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Background: Malocclusion is one of the three major oral diseases and may cause deterioration in oral health-related quality of life (OHRQoL). This study aims to determine the prevalence of malocclusion by gender and its impact on quality of life among 12- and 15-year-old children in Shanghai. Methods: This study summarizes the data obtained in the Shanghai Oral Health Epidemiological Survey conducted in 2019. Random cluster sampling was used to select students in Shanghai. A total of 1591 12-year-old children and 747 15-year-old children were included. Each student underwent an oral examination and completed a questionnaire. The Index of Complexity, Outcome and Need (ICON) was adopted to measure the objective severity of malocclusion and Child Oral Health Impact Profile (COHIP) was applied to evaluate quality of life of schoolchildren. Comparisons of COHIP scores were performed among different treatment needs and difficulties by t-test and analysis of variance (ANOVA). Results: No significant difference was found between genders except that the prevalence of deep overbite in 12-year-old boys (1.11 ± 0.95) was significantly higher than that in girls (0.93 ± 0.88) while the prevalence of crossbite among 12-year-old girls (26%) is significantly higher than boys (20%). Malocclusion in 15-year-old children was descended compared with 12-year-old. 15-year-old students demonstrates larger impact of malocclusion on oral health than 12-year-old group except self-image. Health impacts (COHIP) increase significantly as the malocclusion becomes severer except self-image in 12-year-old group. Conclusions: In Shanghai, the severity of malocclusion in 15-year-old children was less than 12-year-old children. Malocclusion has greater influence on oral health of 15-year-old children than 12-year-old children. Severer malocclusion generally correlates with higher level of oral health impacts in schoolchildren. [ABSTRACT FROM AUTHOR]

Objectives: Temporomandibular disorders (TMDs) have a relatively high prevalence among university students. This study aimed to identify independent risk factors for TMD in university students and develop an effective risk prediction model. Methods: This study included 1,122 university students from four universities in Changchun City, Jilin Province, as subjects. Predictive factors were screened by using the least absolute shrinkage and selection operator (LASSO) regression and the machine learning Boruta algorithm in the training cohort. A multifactorial logistic regression analysis was used to construct a TMD risk prediction model. Internal validation of the model was conducted via bootstrap resampling, and an external validation cohort comprised 205 university students undergoing oral examinations at the Stomatological Hospital of Jilin University. Results: The prevalence of TMD among university students was 44.30%. Ten predictive factors were included in the model, comprising gender, facial cold stimulation, unilateral chewing, biting hard or resilient foods, clenching teeth, grinding teeth, excessive mouth opening, malocclusion, stress, and anxiety. The model demonstrated good predictive ability with area under the receiver operating characteristic curve (AUC) values of 0.853, 0.838, and 0.821 in the training cohort, internal validation cohort, and external validation cohort, respectively. The calibration curves demonstrated that the predicted results were consistent with the actual results, and the decision curve analysis (DCA) indicated the model's high clinical utility. Conclusions: An online nomogram of TMD in university students with good predictive performance was constructed, which can effectively predict the risk of TMD in university students. The model provides a useful tool for the early identification and treatment of TMDs in university students, helping clinicians to predict the probability of TMDs in each patient, thus providing more personalized and accurate treatment decisions for patients. [ABSTRACT FROM AUTHOR]

Background: The determining effect of facial hard tissues on soft tissue morphology in orthodontic patients has yet to be explained. The aim of this study was to clarify the hard-soft tissue relationships of the lower 1/3 of the face in skeletal Class II-hyperdivergent patients compared with those in Class I-normodivergent patients using network analysis. Methods: Fifty-two adult patients (42 females, 10 males; age, 26.58 ± 5.80 years) were divided into two groups: Group 1, 25 subjects, skeletal Class I normodivergent pattern with straight profile; Group 2, 27 subjects, skeletal Class II hyperdivergent pattern with convex profile. Pretreatment cone-beam computed tomography and three-dimensional facial scans were taken and superimposed, on which landmarks were identified manually, and their coordinate values were used for network analysis. Results: (1) In sagittal direction, Group 2 correlations were generally weaker than Group 1. In both the vertical and sagittal directions of Group 1, the most influential hard tissue landmarks to soft tissues were located between the level of cemento-enamel junction of upper teeth and root apex of lower teeth. In Group 2, the hard tissue landmarks with the greatest influence in vertical direction were distributed more forward and downward than in Group 1. (2) In Group 1, all the correlations for vertical-hard tissue to sagittal-soft tissue position and sagittal-hard tissue to vertical-soft tissue position were positive. However, Group 2 correlations between vertical-hard tissue and sagittal-soft tissue positions were mostly negative. Between sagittal-hard tissue and vertical-soft tissue positions, Group 2 correlations were negative for mandible, and were positive for maxilla and teeth. Conclusion: Compared with Class I normodivergent patients with straight profile, Class II hyperdivergent patients with convex profile had more variations in soft tissue morphology in sagittal direction. In vertical direction, the most relevant hard tissue landmarks on which soft tissue predictions should be based were distributed more forward and downward in Class II hyperdivergent patients with convex profile. Class II hyperdivergent pattern with convex profile was an imbalanced phenotype concerning sagittal and vertical positions of maxillofacial hard and soft tissues. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate the condylar morphological changes after orthodontic treatment in adult patients with Class II malocclusion using a Cone-beam computed tomography (CBCT). Methods: Images of twenty-eight adult patients with Class II malocclusion who have no temporomandibular symptoms were involved in this study. To analyze the post-treatment changes in condylar morphology, mimics 17.0 software was used to measure several values and reconstruct the three-dimensional condyle, including height of the condyle, area and bone mineral density of the maximum axial and sagittal section, volume and bone mineral density of the three-dimensional condyle and condylar head before and after orthodontic treatment. Using SPSS 19.0 software package Paired t-test was applied for comparison of condylar morphology analysis between pre-treatment and post-treatment. Results: Height of condylar head increase significant (P <.05). Bone mineral density showed a decrease in the maximum axial and sagittal section, three-dimensional condyle and condylar head (P <.01). Evaluation of volume revealed that volume of both condyle and condylar head decrease considerably (P <.05). No significant difference was detected in other values ((P >.05). Conclusion: Condylar volume decreased and height of condylar head have changed, so we speculated that adaptive bone remodeling of the condyle occurs. [ABSTRACT FROM AUTHOR]

Background: The lateral profile is an important indicator of facial attractiveness. This study explored the general characteristics of the forehead profile and protrusion, and their relationship with related factors in structure and development. Methods: Four hundred fourteen Chinese participants in the Yangtze River Delta region were involved. Including 206 males (17.15 ± 7.68 years old) and 208 females (18.35 ± 8.06 years old); 94 children (8.54 ± 2.21 years old, ranging from 4 to 12 years old), 166 adolescents (14.83 ± 1.50 years old, ranging from 13 to 17 years old), and 154 adults (25.52 ± 4.89, 18 years or older). The frontal section of the forehead was used to explore its shape. The straight distance between the vertical line of the FH plane through the nasal root point and its parallel line, which is tangential to the forehead, indicates the forehead prominence. Frontal sinus width was measured using the method described by Mahmood. Results: The general shape of the forehead was straight and slightly bulged near the eyebrow arch in males but rounder in females. The average forehead protrusion in males was higher than that in females in adults. Significant differences in forehead protrusion between the dentoskeletal classifications and growth phases were notable. Frontal protrusion significantly correlated with frontal sinus depth, especially in males, adults, Class I, and those whose convex points were located in the lower section of the forehead. Conclusions: Age, race, and sex affect the forehead protrusion and frontal sinus width. Forehead protrusion may be an indicator of dentoskeletal deformities in the early stage. And dentoskeletal deformities may impair the correlation between the frontal sinuses and forehead protrusion during development. Trial registration: This retrospective, cross-sectional study was reviewed and approved by the Research Ethical Committee (T2020008), and registered at ClinicalTrial.gov with an identified number (ChiCTR2100041913). [ABSTRACT FROM AUTHOR]

Background: The Malocclusion Impact Scale for Early Childhood (MIS-EC) is a newly developed questionnaire used to measure the parental perceptions of the impact of malocclusion on oral health-related quality of life (OHRQoL) of preschool children aged 3–5 years. This study describes the cross-cultural adaptation and validation of the MIS-EC questionnaire into Chinese version (MIS-EC/C). Methods: The MIS-EC/C was developed in accordance with international standards. The scale was then evaluated in a cross-sectional study comprising 210 preschool children aged 3–5 years. The reliability of the MIS-EC/C was tested using internal consistency and test-retest reliability analyses. Cross-cultural validity, discriminant validity and convergent validity were tested. Results: The Cronbach's α value and intraclass correlation coefficient (ICC) value for the MIS-EC/C were 0.943 and 0.873, respectively. Confirmatory factor analysis indicated that the fitting indicators of the two-factor model all reached the standard. The MIS-EC/C can differentiate preschool children with malocclusion from those without malocclusion. In addition, there is a good relationship between the MIS-EC/C and the general oral health question. Conclusion: The MIS-EC/C is a reliable and effective assessment tool for assessing the effect of malocclusion on the OHRQoL of preschool children in China. [ABSTRACT FROM AUTHOR]

Background: This study is to evaluate and compare the improvement of upper airway morphology and hyoid bone position in children with Class II mandibular retrusion treated with Invisalign mandibular advancement (MA) and Twin-Block (TB) appliances, utilizing cone beam computed tomography (CBCT). Methods: 32 children aged between 8 and 11.5 years old were included in this study, with an average age of 10.2 years old. These children were divided into two groups, MA and TB, with 16 children in each group. Changes in upper airway morphology and hyoid bone position before and after treatment were analyzed using CBCT. Results: (1) Changes in upper airway before and after treatment: the oropharynx volume (Or-V), the oropharynx minimum cross-sectional area (Or-mCSA), the hypopharynx volume (Hy-V), and the hypopharynx minimum cross-sectional area (Hy-mCSA) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05) compared to pre-treatment status. (2) Changes in hyoid bone position before and after treatment: The distances between H point and third cervical vertebra (H-C3), H point and pogonion (H-RGN), H point and mandibular plane (H-MP), H point and Frankfort horizontal plane (H-FH), H and S point (H-S), and H point and palatal plane (H-PP) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05). Conclusion: Both MA and TB appliances effectively improved the structural narrowness of the upper airway and reduced respiratory resistance, thus improving breath quality. However, MA showed more effectiveness in improving the narrowest part of the hypopharynx compared to TB. Both appliances also promoted anterior downward movement of the hyoid bone, which opens the upper airway of the oropharynx and hypopharynx and helps the upper airway morphology return to normal range. [ABSTRACT FROM AUTHOR]

Background: The main purpose of the study was to investigate the prevalence and related risk factors of malocclusion in permanent dentition among adolescents in Shanghai, and provide basic data for government's preventive strategies and intervention plans. Methods: 1799 adolescents aged 11–15 years old from 18 middle schools in 6 districts of Shanghai were recruited to investigate oral health status and related risk factors using cluster random sampling method in 2021. Malocclusion and caries were examined by on-site inspection. The investigation criteria referred to Bjoerk and the recommendation of the WHO. The malocclusion inspection items included molars relationship, canine relationship, overbite, overjet, midline displacement, anterior crossbite, posterior crossbite, scissors bite, crowding and spacing. The subjects were asked to fill in a questionnaire including parents' education level, oral health behaviors and dietary habits. The chi-square test and logistic regression analysis were used to analyze the relationship between malocclusion and risk factors. Results: 1799 adolescents were included in the study and the prevalence of malocclusion in adolescents in Shanghai was 83.5%, and the proportion of molar relationship class I, class II, and class III was 48.9%, 14.7%, and 19.0%, respectively. The most common occlusal characteristic of malocclusion was anterior crowding, followed by midline irregularities and deep overbite, with prevalence rates of 44.8%, 39.0% and 38.6%, respectively. The prevalence rate of adolescents with caries was 34.3%. Those who had dental caries and preferred soft food were more likely to have abnormal occlusal characteristics (p < 0.05). Conclusion: The prevalence of malocclusion in adolescents in Shanghai is high, so it is of great significance to strengthen oral health education, allocate proper preventive strategies and carry out the early correction if necessary. [ABSTRACT FROM AUTHOR]

Copyright of West China Journal of Stomatology is the property of Sichuan University, West China College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of West China Journal of Stomatology is the property of Sichuan University, West China College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: No studies have focused on cortical anchorage resistance in cuspids, this study aimed to characterize the cortical anchorage according to sagittal skeletal classes using cone-beam computed tomography (CBCT). Methods: CBCT images of 104 men and 104 women were divided into skeletal class I, II, and III malocclusion groups. Skeletal and dental evaluations were performed on the sagittal and axial cross-sections. One-way analysis of variance followed by least significant difference post-hoc tests was used for group differences. Multiple linear regression was performed to evaluate the relationship between influential factors and cuspid cortical anchorage. Results: All cuspids were close to the labial bone cortex in different sagittal skeletal patterns and had different inclinations. There was a significant difference in the apical root position of cuspids in the alveolar bone; however, no significant difference in the middle or cervical portions of the root was found between different sagittal facial patterns. The middle of the cuspid root was embedded to the greatest extent in the labial bone cortex, with no significant difference between the sagittal patterns. For all sagittal patterns, 6.03 ± 4.41° (men) and 6.08 ± 4.45° (women) may be appropriate root control angles to keep maxillary cuspids' roots detached from the labial bone cortex. Conclusions: Comparison of skeletal class I, II, and III malocclusion patients showed that dental compensation alleviated sagittal skeletal discrepancies in the cuspid positions of all patients, regardless of the malocclusion class. Detailed treatment procedures and clear treatment boundaries of cuspids with different skeletal patterns can improve the treatment time, periodontal bone remodeling, and post-treatment long-term stability. Future studies on cuspids with different dentofacial patterns and considering cuspid morphology and periodontal condition may provide more evidence for clinical treatment. [ABSTRACT FROM AUTHOR]

This survey examined the prevalence of malocclusion and its associated factors in 3- to 5-year-old children in Huizhou, China. Children were recruited from 21 kindergartens using a multistage sampling method. Two examiners performed oral examinations on the children, assessing occlusal traits, including primary molar and canine relationship, overjet, crossbite, overbite, anterior open bite, scissor bite, midline deviation, crowding, and spacing. Caries experience was recorded. Self-administered questionnaires were distributed to collect background information and oral health-related habits. Chi-square test, Mann–Whitney U test, and binary logistic regression were conducted. The study invited 1485 children and eventually recruited 1454 (52.9% boys; response rate: 97.9%). The prevalence of malocclusion was 68.3%, and deep overbite was found in 48.6% of the children. Children who had lip-biting habits had a higher prevalence of deep overbite than those who did not (OR = 2.36, p < 0.05). Children who had digit-sucking habits and dental caries in anterior maxillary teeth had a lower prevalence of deep overbite than those who did not (OR = 0.73 and 0.70, respectively, p < 0.05). In conclusion, over half of the children in Huizhou who participated in the study had malocclusion. Dental caries in anterior maxillary teeth, digit-sucking, and lip-biting were the associated factors of deep overbite. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to determine the prevalence and independent risk factors of SDB, and explore its association with malocclusion among 6–11-year-old children in Shanghai, China. Methods: A cluster sampling procedure was adopted in this cross-sectional study. Pediatric Sleep Questionnaire (PSQ) was applied to evaluate the presence of SDB. Questionnaires including PSQ, medical history, family history, and daily habits/environment were completed by parents under instruction, and oral examinations were implemented by well-trained orthodontists. Multivariable logistic regression was applied to identify independent risk factors for SDB. Chi-square tests and Spearman's Rank Correlation were used to estimate the relationship between SDB and malocclusion. Results: A total of 3433 subjects (1788 males and 1645 females) were included in the study. The SDB prevalence was about 17.7%. Allergic rhinitis (OR 1.39, 95% CI 1.09–1.79), adenotonsillar hypertrophy (OR 2.39, 95% CI 1.82–3.19), paternal snoring (OR 1.97, 95% CI 1.53–2.53), and maternal snoring (OR 1.35, 95% CI 1.05–1.73) were independent risk factors for SDB. The SDB prevalence was higher in children with retrusive mandibles than in proper or excessive ones. No significant difference was observed in the correlation between SDB and lateral facial profile, mandible plane angle, constricted dental arch form, the severity of anterior overjet and overbite, degree of crowding and spacing, and the presence of crossbite and open bite. Conclusions: The prevalence of SDB in primary students in the Chinese urban population was high and highly associated with mandible retrusion. The independent risk factors included Allergic rhinitis, adenotonsillar hypertrophy, paternal snoring, and maternal snoring. More efforts should be made to enhance public education about SDB and related dental-maxillofacial abnormalities. [ABSTRACT FROM AUTHOR]

Background: According to epidemiological studies, gingivitis is a common disease. However, its morbidity, considerably varies among individual. This study aimed to investigate the epidemiological characteristics of gingivitis, including prevalence, severity, intraoral distribution, and associated risk factors, in children aged 6–12 years in Jinzhou, China. Methods: A multistage, whole-group, randomized sample of 2880 children aged 6–12 years in Jinzhou City, China, was selected and clinically examined. Each selected child completed a questionnaire on sociodemographic factors and oral health behaviors in cooperation with the investigator and teacher. Gingival bleeding refers to the bleeding of 10% or more teeth under the condition of ingivitis. Gingivitis was further categorized into localized gingivitis (30% ≥ number of teeth positive for gingival bleeding ≥ 10%) and generalized gingivitis (number of positive for gingival bleeding > 30%). The score of gingival bleeding was recorded using the Gingival Index. Results: The prevalence of gingivitis in children aged 6–12 years in Jinzhou was 28.58%, including 701 cases of localized gingivitis (24.3%) and 122 cases of generalized gingivitis (4.2%). There were 429 cases (28.3%) of gingivitis in males and 394 cases (28.9%) in females, with no statistically significant difference in prevalence between males and females (P > 0.05). Chi-square tests and binary logistic regression analysis showed that aging, dental calculus, plaque, and dental crowding were significantly associated with a high prevalence of gingivitis. Conclusions: Our study showed that dental calculus, large amount dental plaque, poor oral health behavior, and oral health awareness are associated with the prevalence of gingivitis and maintaining children's oral health requires professional guidance and regular preventive care. [ABSTRACT FROM AUTHOR]

Background: This study aimed to compare the maxillary sinus dimensions and surface area in accordance with skeletal malocclusion, gender and ethnicity factors in a sample of Chinese and Yemeni patients. Methods: This cross-sectional study analysed 180 maxillary sinuses using 180 lateral cephalometric radiographs. The patients were subdivided into two ethnic groups: Chinese and Yemeni. Each ethnic group comprised 90 patients, and men and women were divided equally. Each ethnic group was classified into three skeletal classes using ANB and Wits appraisal (skeletal Classes I, II and III). Pearson's correlation coefficient was also used to assess the relationship between maxillary sinus dimensions and cephalometric parameters. Results: Men had larger maxillary sinuses than women; skeletal Class II had a higher length and surface area increase than other skeletal classes, although skeletal Classes I and II were almost equal in height. Except for the maxillary sinus length, none of these findings were statistically significant. The maxillary sinuses in Chinese are larger than those in Yemenis (P = 0.000). These variables were positively correlated with SNA, SNB and Co–A. The maxillary sinus length and Co–Gn were positively correlated. The NA–APO and NA–FH angles were also correlated with the maxillary sinus surface area. However, the gonial and GoGn–Sn angles negatively affected the maxillary sinus dimension and surface area. Conclusions: Men had larger maxillary sinuses than women in both ethnic groups, and Chinese individuals had larger maxillary sinuses than Yemenis. Skeletal Class II malocclusion of both ethnicities had larger maxillary sinus dimensions. Furthermore, the maxillary sinus dimensions correlated with cephalometric parameters. [ABSTRACT FROM AUTHOR]

Objectives: To quantitatively assess periodontal soft tissue changes, including gingival thickness and keratinized gingiva width after periodontally accelerated osteogenic orthodontics (PAOO) surgery by digital measurements. Methods: This study enrolled 15 maxillaries with 89 anterior teeth and 16 mandibles with 94 anterior teeth from Chinese adult patients with skeletal Angle Class III malocclusion for whom PAOO surgery was proposed during orthodontic treatment. Intraoral scanning and cone beam computed tomography (CBCT) examinations were performed before PAOO surgery and 6 months after the surgery. Keratinized gingiva width was measured on the digital model acquired by intraoral scanning. The gingival thickness was measured using a digital three-dimensional (3D) model based on the combination of digital intraoral scanning and CBCT data. Results: The mean gingival thickness before surgery was 0.91 ± 0.32 mm and 1.21 ± 0.38 mm at 6-month after PAOO. Patients showed periodontal soft tissue increase with a mean gingival tissue gain of 0.30 ± 0.33 mm. At 1 mm, 2 and 3 mm apical to cemento-enamel junction (CEJ) levels, the gingival thickness increase of the mandible was higher than that of the maxilla (0.38 ± 0.30 mm vs. 0.24 ± 0.31 mm, 0.43 ± 0.35 mm vs. 0.26 ± 0.41 mm, 0.36 ± 0.27 vs. 0.25 ± 0.32 mm, respectively, all P < 0.05). Moreover, the sites of gingival thickness ≤ 1 mm before surgery showed more tissue gain than the sites > 1 mm (0.36 ± 0.32 mm vs. 0.18 ± 0.31 mm, P < 0.001). The mean keratinized gingiva width at T0 was 3.88 ± 1.22 mm, and increased 1.05 ± 1.24 mm 6 months after PAOO surgery. Moreover, a digital 3D model for gingival thickness measurement based on the combination of digital intraoral scanning and CBCT displayed high reliability and accuracy with an intra-class correlation coefficient (ICC) of 0.897. Conclusion: PAOO could improve an insufficient quantity of periodontal soft and hard tissues in patients with skeletal Angle Class III malocclusion, including the gingival thickness and keratinized gingiva width. A digital 3D model based on the combination of digital intraoral scanning and CBCT data could provide a new digital measurement of gingival thickness with high accuracy and reliability. [ABSTRACT FROM AUTHOR]

BACKGROUND: At present, the research on the performance of Physiological Anchorage Spee's Wire System (PASS) appliance in China is still in its infancy. Quantitative analysis of the effect of vertical anchorage control using PASS appliance for teenagers is seldom reported. OBJECTIVE: To analyze the relationship between the vertical anchorage control and the changes of jaw plane angle and chin shape in patients with maxillary protrusion treated by PASS appliance. METHODS: 120 patients with maxillary protrusion were treated in the Second Affiliated Hospital of Xingtai Medical College from March 2016 to March 2019. The patients undergoing micro-implant anchorage treatment were randomly divided into observation group and control group, with 60 patients in each group. PASS appliance was used in the control group, and vertical support appliance between the first molars of both sides was used in the observation group. Oral X-ray lateral radiographs were used for imaging diagnosis to compare the effect and the difference of the chin shape between the two groups. RESULTS AND CONCLUSION: (1) At 4 weeks after treatment, the inner lower angle between the upper central incisor and the anterior skull base plane, the inner upper angle between the long axis of the lower central incisor and the mandibular plane, the angle of the mandibular plane, the distance between the two feet, and the distance from the lower lip bump to the aesthetic plane were significantly lower in the observation group than those of the control group (P < 0.05). The angle of the long axis of the upper and lower central incisors was significantly higher in the observation group than that of the control group (P < 0.05). (2) At 4 weeks after treatment, the apical point chin thickness, anterior chin thickness, chin depression, chin inclination, and chin soft tissue thickness of the observation group were significantly lower than those of the control group (P < 0.05), and the chin height, chin protrusion, and chin curvature and the depth of the soft tissue depression of the chin were significantly higher than those of the control group (P < 0.05). (3) It is concluded that in the treatment of patients with malocclusion, compared with PASS appliance, micro-implant anchorage combined with vertical control measures can effectively improve the shape of the chin, and the effect is significant. [ABSTRACT FROM AUTHOR]

Background: A growing number of Chinese residents are seeking orthodontic treatment. The aim of the study was to investigate rates of orthodontic publicity, orthodontic treatment history and related factors among college freshmen in China, to preliminarily understand the current situation of orthodontic publicity and treatment in China, especially after the 2020s. Methods: Referred to previous studies, a self-designed online questionnaire of Chinese college freshmen was conducted. The questionnaire was divided into two parts, after collecting basic information, we investigated orthodontic publicity rate and orthodontic treatment history with starting age, relapse phenomenon, satisfaction score and willingness to re-treatment. Factors hindering first-time and second-time treatment were also collected. The statistical analysis was performed using the Chi-square test, t-test, Kruskal–Wallis test and logistic regression analysis. Results: The response rate was 100% and 3308 responses were included. The male to female ratio was 1524:1784 with a mean age of 18.43 years (SD 0.91 years). Statistically significant of economic administrative regions, age, major and orthodontics engagement of relatives or friends were found on prevalence and rate of orthodontic treatment (P < 0.05). Average opinion on orthodontic treatment was "satisfied" and most claimed a phenomenon of relapse (slight relapse: 38.22%, obvious relapse: 23.12%), where age, major and orthodontics engagement of relatives or friends showed statistically significant. Retreatment willingness was correlation with start age and relapse phenomenon. For those who refused first-time treatment, except for good tooth arrangement condition, pain, long-time span, and cost weighted, while for those who refused re-treatment, the fair of discomfort and long-time span ranked at the top. Conclusions: In contemporary China, the prevalence and rate of orthodontic treatment had been greatly promoted. Earlier age for receiving orthodontic treatment was also discovered. Subjective factors regarding psychology, self-requirement affected the need of orthodontic treatment. Contemporary Chinese college freshmen had a high ability of judging dental alignment, while improve of overall orthodontic care level is still required. [ABSTRACT FROM AUTHOR]

Objectives: Machine learning is increasingly being used in the medical field. Based on machine learning models, the present study aims to improve the prediction performance of craniodentofacial morphological harmony judgment after orthodontic treatment and to determine the most significant factors. Methods: A dataset of 180 subjects was randomly selected from a large sample of 3,706 finished orthodontic cases from six top orthodontic treatment centers around China. Thirteen algorithms were used to predict the value of the cephalometric morphological harmony score of each subject and to search for the optimal model. Based on the feature importance ranking and by removing features, the regression models of machine learning (including the Adaboost, ExtraTree, XGBoost, and linear regression models) were used to predict and compare the score of harmony for each subject from the dataset with cross validations. By analyzing the prediction values, the most optimal model and the most significant cephalometric characteristics were determined. Results: When nine features were included, the performance of the XGBoost regression model was MAE = 0.267, RMSE = 0.341, and Pearson correlation coefficient = 0.683, which indicated that the XGBoost regression model exhibited the best fitting and predicting performance for craniodentofacial morphological harmony judgment. Nine cephalometric features including L1/NB (inclination of the lower central incisors), ANB (sagittal position between the maxilla and mandible), LL-EP (distance from the point of the prominence of the lower lip to the aesthetic plane), SN/OP (inclination of the occlusal plane), SNB (sagittal position of the mandible in relation to the cranial base), U1/SN (inclination of the upper incisors to the cranial base), L1-NB (protrusion of the lower central incisors), Ns-Prn-Pos (nasal protrusion), and U1/L1 (relationship between the protrusions of the upper and lower central incisors) were revealed to significantly influence the judgment. Conclusion: The application of the XGBoost regression model enhanced the predictive ability regarding the craniodentofacial morphological harmony evaluation by experts after orthodontic treatment. Teeth position, teeth alignment, jaw position, and soft tissue morphology would be the most significant factors influencing the judgment. The methodology also provided guidance for the application of machine learning models to resolve medical problems characterized by limited sample size. [ABSTRACT FROM AUTHOR]

In spite of the widespread use of functional appliances, broad variations were applied the treatment response. The aim of this study is to investigate the pre-treatment cephalometric predictors on the chin advancement of twin-block in growing Chinese patients with class II malocclusion. After screening, 90 patients treated by twin-block were included in the study. The treatment outcome was assessed by the alterations in the distance of skeletal pogonion (Pog) to the vertical reference plane perpendicular to the Frankfurt plane (ΔPog-VRP). Moreover, ΔPog-VRP was divided by the cranial growth indicated by the Nasion to Basion changes (ΔN-Ba) to minimize the growth discrepancy among individuals (adjΔPog-VRP). Patients with ΔPog-VRP/adjΔPog-VRP above the median value were categorized into good response group (GRG/adjGRG, N = 45), while the rest were poor response group (PRG/adjPRG, N = 45). Independent t -test was used to compare the pre-treatment cephalometric measurements between GRG/adjGRG and PRG/adjPRG. Stepwise multivariate regression models were used to determine the pre-treatment cephalometric predictors for the chin advancement. Generally, there were not any significant differences between GRG/adjGRG and PRG/adjPRG regarding age, gender and cervical stage before twin-block treatment. Patients from GRG had significantly reduced cephalometric measurements in the vertical dimensions, including ∠N-Go-Me, ∠Mandibular plane-Occlusal plane (∠MP-OP) and the sum of angles ( p < 0.05) in comparison to PRG. When the individual growth was taken account, similar findings were observed. The patients from adjGRG had a significantly lower ∠Sella Nasion line-MP (∠SN-MP), ∠Ar-Go-Me and ∠N-Go-Me, as well as an increased Posterior facial height (PFH)/Anterior facial height (AFH) ( p < 0.05) compared with their counterparts. ∠N-Go-Me variable was the independent predictor on Pog advancement with (β = -0.26, 95% CI: -0.06 to -0.01, p = 0.01) and without (β = -0.29, 95% CI: -0.06 to -0.01, p < 0.01) adjustments on individual growth. The results of this study showed that patients with a reduced N-Go-Me angle are more likely to experience a greater chin advancement following twin-block treatment., Competing Interests: The authors declare no conflict of interest., (©2024 The Author(s). Published by MRE Press.)

Copyright of West China Journal of Stomatology is the property of Sichuan University, West China College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To translate and cross-culturally adapt the Malocclusion Impact Questionnaire (MIQ) into Chinese and to assess the psychometric properties of the Chinese version of the MIQ (MIQ/C) for use among adolescents with malocclusion in China. Materials and method: First, the MIQ/C was developed according to international guidelines. Then, the MIQ/C was filled out by 536 adolescents between 10 and 16 years of age. This study used exploratory factor analysis (EFA), confirmatory factor analysis (CFA), convergent validity, internal consistency, and test-retest reliability to evaluate the psychometric properties of the MIQ/C. Results: Following EFA, three domains were extracted, accounting for 65.950% of the total variance. The CFA results showed that the fit indices of each factor in the three-factor model all reached the standard (chi-square/DF = 2.591, GFI = 0.919, TLI = 0.926, CFI = 0.928, RMSEA = 0.076). The scale evidenced a good relationship with the two global questions, indicating good convergent validity. The Cronbach alpha value and the intraclass correlation coefficients (ICC) value of the MIQ/C were 0.929 and 0.893, respectively. Conclusion: The MIQ/C demonstrated good reliability and validity and can be further studied and applied in Chinese adolescents with malocclusion. Clinical relevance: The MIQ/C can be applied to assess the psychosocial impact of malocclusion among Chinese adolescents. [ABSTRACT FROM AUTHOR]

Background: To investigate soft- and hard-tissue changes after augmented corticotomy in Chinese adult patients with skeletal Angle Class III malocclusion.Methods: This non-randomized controlled trial included 357 anterior teeth from 30 Chinese adult patients with skeletal Angle Class III malocclusion for whom the proposed treatment was augmented corticotomy. Jaws receiving surgery were allocated to a test group (S, surgical group, n = 47) and jaws not receiving surgery were allocated to a control group (NS, non-surgical group, n = 13). Changes in the periodontal biotype, width of the keratinized gingiva (WKG), and labial and lingual horizontal bone thicknesses (BTs) were compared 6 months after surgery by univariate and multivariate analyses.Results: After adjustment for confounding variables, average gains of 0.473 mm in the WKG and 0.649 mm in the labial BT were found in the S group relative to the NS group (P <0.05). The odds of transition from a thin periodontal biotype to a thick biotype in the S group were about 230 times those in the NS group, and the odds of the reverse biotype transition in the NS group were about 83 times those in the S group (P <0.05).Conclusions: Within the limitations of the present study, augmented corticotomy is a promising approach to improve insufficient periodontal soft and hard tissues in Chinese adult patients with skeletal Angle Class III malocclusion. [ABSTRACT FROM AUTHOR]

Background: Malocclusion is a common oral health problem in schoolchildren. Literature describing the prevalence of malocclusion varies substantially across China. Aim: This study identified the epidemiological characteristics of malocclusion among Chinese schoolchildren from 1991 to 2018. Design: Six English and Chinese electronic databases were searched through November 2018. The search was supplemented by hand searching to identify relevant surveys. The overall prevalence of malocclusion was estimated by a random‐effects meta‐analysis model, and variations in different groups were assessed by subgroup meta‐analysis. Results: Thirty‐seven eligible articles describing 117 682 samples were investigated. The pooled national prevalence for malocclusion was 47.92% (95% CI: 58.6%‐71.9%). For the Angle classification, the overall prevalence rates were 30.07% (95% CI: 25.37%‐35.48%), 9.91% (95% CI: 7.41%‐13.79%), and 4.76% (95% CI: 3.85%‐6.54%) for Class I, Class II, and Class III malocclusion, respectively. A deep overbite (16.67%, 95% CI: 11.50%‐23.08%) was shown to be the most common trait of malocclusion. When stratified by sex, males had a slightly higher prevalence than females (RR = 1.04, 95% CI: 1.01‐1.06). More importantly, an ascending trend and substantial variations across the country were observed. Conclusions: Our results confirmed that malocclusion has become a serious oral health problem in Chinese schoolchildren, highlighting the need for proactive interventions at an early age. Moreover, high‐quality epidemiological studies on malocclusion are still required. [ABSTRACT FROM AUTHOR]

Objective: This study examined the relationships between skeletal deformities and the pharyngeal airway of patients with nonsyndromic unilateral cleft lip and palate (UCLP). Design: Retrospective study. Setting: Orthodontics and Oral and Maxillofacial Surgery Departments in the Affiliated Hospital of Stomatology, Nanjing Medical University, China. Patients, Participants: The sample comprised 30 nonsyndromic UCLP patients and 30 healthy controls. Each group has 23 males and 7 females. Interventions: All cone-beam computed tomography images were obtained with the participant in the standard supine position and asked to bite with intercuspal position without swallowing or moving their heads and tongues during scanning. Main Outcome Measure(s): SNA, SNB, ANB, anterior cranial base, Wits appraisal, maxillary length (PTM-ANS || FH), maxillary position (S-PTM || FH), mandibular length (Go-Pog || MP), FMA, posterior face height, anterior face height, Posterior-Anterior face height, lower face height, pharyngeal airway volumes, and areas were evaluated by Dolphin imaging software. Results: The UCLP group showed significantly decreased SNA, SNB, ANB, PTM-ANS || FH, S-PTM || FH, P-A Face Height compared with the controls. However, the airway volumes and areas showed no significant difference between 2 groups. The total airway volume and minimum cross-sectional area in UCLP patients were related to the Go-Pog || MP and FMA. Conclusions: Patients with UCLP have both the maxillary and mandibular deficiencies in the sagittal dimension. Both the sagittal and vertical relationships of the jaw might affect the airway volume and area. However, no significant difference was detected in airway volume and area in UCLP patients when compared with the controls. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate the occlusion, the demand for orthodontic treatment and the reasons for this among Chinese young adults in Hong Kong. Materials and Methods: A questionnaire was used to study previous orthodontic experience and to evaluate the orthodontic treatment demand and the reasons for this in Chinese university students. Among those who had no orthodontic treatment, 120 participants were invited for an occlusal assessment. Their treatment need was graded using the index of orthodontic treatment need. Results: A total of 240 students, aged 18 to 27 years, completed the questionnaire survey. Thirty-one students (13%) had orthodontic treatment. Sixty-seven (28%) students had orthodontic treatment demand, and their common reasons were to improve appearance (78%), self-image (36%), self-confidence (34%) as well as to follow parental advice (24%). The reasons for those students who would not consider having orthodontic treatment included no perceived need (64%), long treatment time (18%) and high treatment fee (14%). All 120 invited participants who had no orthodontic treatment attended the occlusal assessment. One-fifth had a normal occlusion. Most malocclusions were manifested as Angle Class I (48%) followed by Class III (21%) malocclusion. Fifty-six students (47%) had moderate and 40 students (33%) had 'great' or 'extremely great' treatment need. Conclusions: The most prevalent malocclusion among this group of Chinese young adults was Angle Class I malocclusion. Although the majority of the Chinese young adults had malocclusion with a high treatment need, their demand for orthodontic treatment was relatively low. Apart from consideration of dental health needs, the common reasons for orthodontic treatment demand were influenced by the desire for improvement in appearance. [ABSTRACT FROM AUTHOR]

Background: The anatomical relationship between the root apices of maxillary molars and the maxillary sinus floor (MSF) is important for the treatment of dental implantations and endodontic procedures. In this study, the detailed anatomical relationships between the root apices of maxillary molars and the MSF were studied in a Chinese population using CBCT. Methods: We collected the CBCT data files of patients who visited the stomatology outpatient clinic in Shanghai Fifth People's Hospital, Fudan University from January 1, 2017 to January 1, 2019 and measured the following items: the distance between the molar root apices and the MSF, the thickness of the mucosa and cortical bone of the MSF closest to the root apices, and the angle between the buccal and palatal roots. Results: The shortest distances between the root apices and the MSF were 1.57 ± 3.33 mm (the mesiobuccal root of the left second molar) and 1.61 ± 3.37 mm (the mesiobuccal root of the right second molar). Apical protrusion over the inferior wall of the sinus most often occurred in the mesiobuccal root of left second molar (frequency, 20.5%). The mucosa of the MSF was thinnest at the distobuccal root of the right second molar (1.52 ± 0.85 mm), the cortical bone of the MSF was thinnest at the mesiobuccal root of the right second molar (0.46 ± 0.28 mm), and the angle between the buccal and palatal roots ranged from 12.01° to 124.2° (42.36 ± 24.33 °). Conclusions: Among the root apices of the maxillary molars, the mesiobuccal root apex of the left second molar was closest to the MSF, and it had the highest incidence of protrusion into the sinus. The unique anatomical relationship between the maxillary molars and the MSF in this Chinese population is critical for treatment planning for dental implantation or endodontic procedures. [ABSTRACT FROM AUTHOR]

Objectives: To assess the validity of the American Board of Orthodontics Discrepancy Index (ABO-DI) and Peer Assessment Rating (PAR) Index in evaluating malocclusion severity in Chinese orthodontic patients.Setting and Sample Population: A stratified random sample of 120 orthodontic patients based on Angle classification was collected from six university orthodontic centres.Material and Methods: Sixty-nine orthodontists rated malocclusion severity on a five-point scale by assessing a full set of pre-treatment records for each case and listed reasons for their decision. Their judgement was then compared with ABO-DI and PAR scores determined by three calibrated examiners.Results: Excellent interexaminer reliability of clinician judgement, ABO-DI and PAR index was demonstrated by the Intraclass Correlation Coefficient (rho= 0.995, 0.990 and 0.964, respectively). Both the ABO-DI and US-PAR index showed good correlation with clinician judgement (r=.700 and r=.707, respectively). There was variability among the different Angle classifications: the ABO-DI showed the highest correlation with clinician judgement in Class II patients (r=.780), whereas the US-PAR index showed the highest correlation with clinician judgement in Class III patients (r=.710). Both indices demonstrated the lowest correlations with clinician judgement in Class I patients.Conclusion: With strong interexaminer agreement, the panel consensus was used for validating the ABO-DI and US-PAR index for malocclusion severity. Overall, the ABO-DI and US-PAR index were reliable for measuring malocclusion severity with significantly variable weightings for different Angle classifications. Further modification of the indices for different Angle classification may be indicated. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the effects of a Twin-block appliance on the condyles of patients with ClassⅡmalocclusion by conducting a systematic review and a Meta-analysis., Methods: Pubmed, Embase, Cochrane Library, Chinese BioMedical Literature Database, China National Knowledge Infrastructure, and VIP Database were electronically searched. Randomized controlled trials, controlled clinical trials, and single-arm trials on condylar changes produced by a Twin-block appliance in patients with ClassⅡmalocclusion were included. Two reviewers independently extracted and assessed the risk of bias. Meta-analyses were conducted with Review Manager 5.3., Results: Eight studies were included; among which, seven were of high quality. After treatment with a twin block appliance, condyles moved anteriorly. The anterior joint spaces decreased ( P <0.000 01), whereas the posterior spaces increased ( P <0.000 01). The superior spaces were not changed ( P =0.11). Moreover, a significant difference was observed in the increase of the condylar space index ( P <0.000 01). After treatment, the anteroposterior diameters of the condyles and condylar height increased ( P =0.000 2 and P <0.000 01, respectively). By contrast, no significant changes were discovered in the medial external diameters of the condyles ( P =0.42)., Conclusions: A Twin-block appliance can promote the growth of a condyle in the posterior and upper direction and move it forward in favor of the correction of Class Ⅱ malocclusion.

Objective: This study aims to investigate the clinical effectiveness of muscle function training combined with occlusal inducers in the treatment for children's malocclusion after obstructive sleep apnea（OSA） surgery. Methods: A total of 40 pediatric patients who underwent surgery for OSA at Shanghai Children's Medical Center, affiliated with Shanghai Jiao Tong University School of Medicine, from January 2020 to December 2021 were involved in this study. They were divided into a treatment group（ n =20） and a control group（ n =20）. The treatment group received muscle function training combined with occlusal inducers, while the control group received muscle function training alone. Cephalometric measurements of hard tissues were compared between the two groups before and 12 months after surgery. Additionally, the OSA-18 questionnaire, which includes 18 items to assess the life quality of children with OSA, was filled out before surgery, 6 months after surgery, and 12 months after surgery by these patients. Results: ①The scores of sleep disorders, physical symptoms, emotional status, daytime sleepiness and energy status and the degree of influence on guardians in the two groups were significantly improved at 12 months after operation（ P <0.05）. The scores of sleep disorders, physical symptoms, emotional status and the degree of influence on guardians in the treatment group were better than those in the control group（ P <0.05）. ②Cephalometric data at 12 months after operation showed that the upper and lower alveolar seat angle（ANB）, Overbite, upper and lower central incisor angle（U1-L1） and Overjet in the treatment group were lower than those in the control group at 12 months after operation, and the difference was statistically significant（ P <0.05）. Conclusion: Children with OSA can improve the dentition irregularity by muscle function training combined with occlusal inducer after operation, and the effect is better than that of muscle function training alone., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Purpose: To investigate the prevalence, clinical manifestations and related risk factors of malocclusion in schoolchildren of Jinzhou City, China., Materials and Methods: A total of 2162 children aged 6-12 years were randomly selected from various districts of Jinzhou. Conventional clinical examination was performed by stomatologists, and the results were described based on different clinical manifestations of malocclusion and individual normal occlusion. Further, a questionnaire survey completed by children's parents or guardians provided the demographic data, lifestyle, and oral habits. The distribution of individual normal occlusion and malocclusion was documented in percentage, and Pearson's Χ2 was used for two-factor analysis. The data were statistically analysed using SPSS software (version 25.0) with a significance level of α = 0.05., Results: A total of 1129 boys and 1033 girls were included in this study, i.e. 52.2% and 47.8% of the total number of children, respectively. The prevalence of malocclusion in children aged 6-12 years old in Jinzhou was 67.9%, of which crowded dentition was the most common form, with a prevalence of 71.8%, followed by deep overbite, anterior crossbite, dental spacing, deep overjet, anterior edge-to-edge occlusion, and anterior open bite. In the logistic regression model, the results showed that BMI index had little effect on the occurrence of malocclusion (p > 0.05), while dental caries, bad oral habits, retained primary teeth, and a low labial frenum were all related to the occurrence of malocclusion (p < 0.05). Moreover, the higher frequency and duration of bad oral habits were associated with a higher likelihood of malocclusion., Conclusions: The prevalence of malocclusion in children aged 6-12 years in Jinzhou is high. In addition, bad oral habits (such as lip biting, tongue thrusting, biting/gnawing objects, unilateral chin supporting, and unilateral mastication) and other related risk factors (such as dental caries, mouth breathing, retention of primary teeth, and low labial frenum, etc) were associated with malocclusion.

Background: Malocclusion is a common disease of oral and maxillofacial region. The study was aimed to investigate levels changes of periodontal pathogens in malocclusion patients before, during and after orthodontic treatments, and to confirm the difference between adults and children. Method: One hundred and eight malocclusion patients (46 adults and 62 children at the school-age) were randomly selected and received orthodontic treatment with fixed orthodontic appliances. Subgingival plaques were Porphyromonas gingivalis (P.gingivalis), Fusobacterium nucleatum (F. nucleatum), Prevotella intermedia (P. intermedia) and Tannerella forsythensis (T. forsythensis) collected from the observed regions before and after treatment. Clinical indexes, including plaque index (PLI), gingival index (GI), sulcus bleeding index (SBI), probing depth (PD) and attachment loss (AL) of observed teeth were examined. Results: The detection rates of P.gingivalis, F. nucleatum, P. intermedia and T. forsythensis increased from baseline to the third month without significant difference, and then returned to pretreatment levels 12 month after applying fixed orthodontic appliances. Adults' percentage contents of P.gingivalis, F. nucleatum, P. intermedia and T. forsythensis were significantly higher than those of children at baseline and the first month, but not obvious at the third month. PLI and SBI were increased from baseline to the first and to the third month both in adults and children groups. Besides, PD were increased from baseline to first month, followed by a downward trend in the third month; however, all patients were failed to detect with AL. Conclusions: Periodontal and microbiological statuses of malocclusion patients may be influenced by fixed orthodontic appliances in both adults and children, more significant in children than in adults. Some microbiological indexes have synchronous trend with the clinical indexes. Long-term efficacy of fixed orthodontic appliances for malocclusion should be confirmed by future researches. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the prevalence and associated factors of malocclusion among children with primary dentition in Xi'an, China. Methods: A total of 2,974 subjects were selected from local schools in Xi'an city using a stratified cluster sampling method from January to September 2015. After screening samples according to the inclusion criteria, the final sample size comprised 2,235 pre-school children, with a mean age of 4.82 (SD, 1.76; range, 2.63-6.12) years. Malocclusion traits were assessed by trained clinicians followed by the evaluation of associated factors through clinical examination and a precisely designed questionnaire including data regarding gender, birth place, parental education level, monthly familial income, parental attitude toward the problem of malocclusion, feeding methods of the children, feeding postures, pacifier use, and delivery methods. Data were analyzed using the Chi-square test and logistic regression analysis. Results: The most common type of malocclusion was increased overjet (34.99 %) in the sagittal direction, deep overbite (37.58 %), and midline deviation (25.32 %) in the vertical and transverse directions, respectively. The prevalence of posterior crossbite, anterior crossbite, and anterior open bite was 7.56, 6.80 and 6.98 %, respectively. The prevalence of the anterior edge-to-edge occlusion was the lowest (2.46 %). The variables associated with malocclusion (P < 0.05) were birth place (odds ratio [OR] = 1.741 with 95 % CI of 1.384-2.162), insufficient abrasion of primary canines (OR = 1.465; 95 % CI of 1.153-1.894), caries in primary teeth (OR = 2.045; 95 % CI of 1.665-2.539), tongue thrusting (OR = 2.833; 95 % CI of 1.640-3.649), mandibular prognathism (OR = 2.621; 95 % CI of 1.574-3.689), and finger sucking (OR = 1.573 with 95 % CI of 1.098-2.014). The feeding methods (OR = 3.614 with 95 % CI of 3. 087-4.596) along with the method of delivery (OR = 1.847 with 95 % CI of 1.323-2.451) have been observed to play an important role in the morbidity of malocclusion (P < 0.05). Conclusions: The prevalence of malocclusion among pre-school children in Xi'an is higher compared to that in other geographical parts of China. Therefore, early attention to the development of occlusion and necessary interventions toward the associated factors are important to reduce its prevalence and further adverse effects. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study is to evaluate the psychosocial impact of dental aesthetics in undergraduate students in the People's Republic of China and to investigate the association between normal orthodontic treatment needs, psychosocial impact of dental aesthetics, and desire for orthodontic treatment. Materials and methods: A cross-sectional study was carried out in two universities in a city of the People's Republic of China with 374 young adults aged between 19 years and 24 years. The students answered a Chinese version of the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) and addressed their desire for orthodontic treatment. Objective malocclusion severity was assessed with the Index of Orthodontic Treatment Need (IOTN). Statistical analysis was performed by the SPSS software (Version 15.0). Results: There was no statistical sex difference in relation to the dental health component of IOTN (P=0.893) and PIDAQ scores (P=0.06), but it was found that the desire for orthodontic treatment was significantly stronger among females. The total and subscale PIDAQ scores and malocclusion severity differed significantly among the five grades of desire (P<0.01). Significant positive correlation was found among desire for orthodontic treatment, IOTN-dental health component grades, and total or subscale PIDAQ scores (P<0.01). High correlation was found between desire and PIDAQ score (r=0.93). Conclusion: The desire for orthodontic treatment is higher among female young adults who have the same orthodontic treatment needs compared to males. The desire for orthodontic treatment has high positive correlation with PIDAQ scores and increases with the increase in self-perceived psychosocial impacts of malocclusion and the needs for orthodontic treatment. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate the relationships of sagittal skeletal discrepancy, natural head position (NHP), and craniocervical posture in young Chinese children with average vertical facial pattern.Methods: Ninety patients with average Frankfort mandibular plane angle (FH/ML) were classified into skeletal class I, II, and III relationships according to their ANB angle. Cephalometric radiographs in NHP were taken. Variables representing sagittal and vertical craniofacial morphology, head posture, and craniocervical posture were measured and compared.Results: Subjects in the skeletal class II group showed the largest craniovertical angles and craniocervical angles, while subjects in the skeletal class III group exhibited the smallest craniovertical angles and craniocervical angles, though not all the measurements showed significant differences. The angle formed by the nasion-sella line and the tangent to the posterior border of the mandibular ramus (NSL/RL) was largest in the skeletal class II group and smallest in the skeletal class III group (p = 0.05).Discussion: Significant differences exist in NHP and craniocervical posture among skeletal class I, II, and III relationships in young Chinese children. Subjects with skeletal class II relationship tended to exhibit more extended head, and children with skeletal class III relationship often exhibited flexed head. [ABSTRACT FROM AUTHOR]

Objective: The aim of the current study is to explore country of origin and social race category differences in dental crowding prevalence through an anthropological approach., Design: Data were collected from individuals within five countries (Australia, China, Japan, South Africa, United States; n = 1008) and seven social race groups in two countries (American Black, American White, Latinx, and Indigenous in the United States, South African Black, South African White, and South African Coloured; n = 654). Statistical significance between groups was assessed with a Kruskal-Wallis test, while a Dunn's post-hoc test identified which groups significantly differed., Results: Results indicate South Africa is characterized by the lowest frequencies of dental crowding, with Coloured South Africans yielding the highest and Black South Africans displaying the lowest frequencies. Individuals in the United States exhibited relatively high levels of minor dental crowding. American Blacks had lower crowding levels, while the Indigenous group had high levels of severe crowding. Individuals within China and Japan exhibited higher relative prevalence of severe crowding., Conclusions: Overall, significant differences exist in dental crowding prevalence across countries and social race categories using an anthropological grading system to assess crowding. These differences are likely impacted by sociocultural (aesthetic preferences) and economic (access to dental care) factors., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: The objectives of this study were to investigated changes in OHRQoL among patients with different classifications of malocclusion during comprehensive orthodontic treatment. Methods: Clinical data were collected from 81 patients (aged 15 to 24) who had undergone comprehensive orthodontic treatment. Participants were classified 3 groups: Class I (n = 35), II (n = 32) and III (n = 14) by Angle classification. OHRQoL was assessed using the Oral Health Impact Profile (OHIP-14). All subjects were examined and interviewed at baseline (T0), after alignment and leveling (T1), after correction of molar relationship and space closure (T2), after finishing (T3). Friedman 2-way analysis of variance (ANOVA) and Wilcoxon signed rank tests were used to compare the relative changes of OHRQoL among the different time points. A Bonferroni correction with P < 0.005 was used to declare significance. Results: Significant reductions were observed in all seven OHIP-14 domains of three groups except for social disability (P > 0.005) in class I and class II, Handicap in class II and class III (P > 0.005). Class I patients showed significant changes for psychological disability and psychological discomfort domain at T1, functional limitation, physical pain at T2. Class III patients showed a significant benefit in all domains except physical pain and functional limitation. Class II patients showed significant changes in the physical pain, functional disability, and physical disability domains at T1. Conclusions: The impact of comprehensive orthodontic treatment on patients' OHRQoL do not follow the same pattern among patients with different malocclusion. Class II patients benefits the most from the stage of space closure, while class I patients benefits the first stage (alignment and leveling) of treatment in psychological disability and psychological discomfort domains. [ABSTRACT FROM AUTHOR]

Treatment outcomes of Angle Class II subdivision malocclusions may be compromised because of the uncertainty of the aetiology. Previous studies have reported controversial ideas about the origins, but the existence of a primary contributor still remains unknown. Functional factors have been mentioned as a probable cause, but until now, there have been no supporting data. This study was a cross-sectional investigation of the characteristics of Angle Class II subdivision malocclusion, including dental, skeletal and functional factors, by comparison of the subdivision group and the normal occlusion group. The evaluations of dental and skeletal asymmetries of both groups were carried out by cone-beam computed tomography ( CBCT) and analysis of dental casts. The functional deviations were evaluated by cast mounting and measuring. In the subdivision group, the asymmetric position of the glenoid fossa was found to be the most significant skeletal asymmetry. No dentoalveolar asymmetry was found in this group. The most important finding was that, in subdivision malocclusions, functional deviation resulting in pseudoasymmetry occurred in 32·86% of the study participants. This deviation is probably related to the disharmonious arch width between maxillary and mandibular dental arches in the premolar section. The origin of Angle Class II subdivision malocclusion is multifactorial, with dental, skeletal and functional factors included. Functional deviation occurs, probably due to dental arch width disharmony. Asymmetric position of the glenoid fossa may account for most of the skeletal asymmetry. [ABSTRACT FROM AUTHOR]

This study aimed to assess generic health-related quality of life (HRQoL), pain intensity, and anxiety levels and the relationship between the three aspects in healthy young Chinese orthodontic patients in the early stage of orthodontic treatment. We enrolled 252 eligible participants (10–29 years old) to complete validated Chinese versions of questionnaires, including the State-Trait Anxiety Inventory (S-AI), the visual analogue scale (VAS), and the Short-Form 36-Item Health Survey (SF-36) at baseline and on days 1, 2, 3, 7, 14, and 30 after initial archwire placement (SF-36 only at baseline and day 30). The response rate was 96% (243 of 252). SF-36 had moderate reliability (Cronbach's alpha coefficient exceeding 0.7, good fit on day 30). Statistical significant changes were observed in physical function (P<0.01), body pain (P=0.01), and general health (P<0.01) domains. Spearman correlation coefficients for SF-36 with S-AI were −0.131~−0.515 (P<0.05); SF-36 with VAS were −0.141~−0.273 (P<0.05), indicating significant but moderate negative correlations between HRQoL and pain/anxiety. Overall, the application of SF-36 in assessing HRQoL is reluctantly suitable for young Chinese orthodontic patients in the early stage of orthodontic treatment. Early treatment-related pain and anxiety are important factors in HRQoL. [ABSTRACT FROM AUTHOR]

To assess associations between occlusal tooth wear and shortened dental arches ( SDA) in Chinese 40 years and older subjects. From a sample of 1462 urban and rural adults, those presenting with SDA ( n = 150) were compared with a control group of 65 randomly selected subjects with complete dentitions ( CDA). Occlusal wear was assessed using a modified Smith and Knight index - the occlusal tooth wear index ( OWTI) - and analysed using multivariate (logistic) regression. There was no significant effect from SDA on severe occlusal wear ( OTWI score 3 or 4: OR = 2·016; 95% CI = 0·960-4·231; P = 0·064). Higher age was associated with severe occlusal wear ( P values ≤0·007) and with higher mean OTWI scores; urban had less often severe occlusal wear than rural residents ( OR = 0·519; P = 0·008). Higher mean OTWI scores were associated with rural residents, except for anterior teeth. Females had lower mean OTWI score for anterior teeth (effect = −0·153; P = 0·030). Premolars in SDA had higher mean OTWI scores compared with those in CDA (effect = +0·213; P = 0·006). In SDA, more posterior occluding pairs ( POPs) were associated with lower mean OTWI sores for anterior teeth (effect: −0·158; P = 0·008) and higher scores for molars (effect: +0·249, P = 0·003). Subjects with SDA or CDA presented comparable occlusal wear, but premolars in SDA tend to have higher probability for having occlusal wear. Fewer numbers of POPs were associated with more wear in anterior teeth. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to evaluate the morphological and dimensional variations of the frontal air sinuses in a group of adolescent Caucasians and Chinese with different skeletal malocclusions in both genders., Materials and Methods: This retrospective study included 290 adolescent Caucasians and Chinese patients with 145 each. Each sample included 90 females and 55 males and was categorized based on ANB angle in reference to each population norms into 65 skeletal class I, 50 skeletal class II, and 30 skeletal class III malocclusions. All linear, angular, and surface area measurements of the frontal air sinuses were evaluated using lateral cephalometric radiographs and calculated using Winceph version 8 software. The frontal air sinus parameters were compared between genders and the two ethnic groups using an independent sample t-test. ANOVA with Tukey's post hoc tests were used to compare the frontal air sinus parameters between the three skeletal malocclusions., Result: The frontal air sinus width and surface area were found to be significantly greater in Caucasians when compared with Chinese patients. According to gender, the frontal air sinus length, width, and surface area, as well as the glabella convexity, were greater in males than females, while the frontal air sinus index (length/width) was significantly greater in females than males in both ethnic groups. In both ethnic groups, the frontal air sinus surface area was significantly greater in skeletal class III malocclusion when compared to skeletal class I and class II malocclusions in Caucasians (P = 0.0022) and Chinese (P = 0.0097). There was a weak-to-moderate correlation between the frontal air sinus parameters and the nasio, sella, and glabella positions (R = -0.56 to 0.62)., Conclusion: The frontal air sinus dimensions and surface area varied greatly in between ethnic groups, genders, and malocclusion types. The frontal air sinus parameters were correlated with nasion, sella, and glabella positions., Clinical Relevance: These findings could assist orthodontists, ENT specialist, and forensic medical investigators to focus on the size of frontal sinus during treatment planning, the relationship between the size of frontal air sinus and malocclusions, and age determination., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

PURPOSE: The aim of this study is to evaluate the vertical relationship of maxilla and mandible with overbite depth indicator (ODI) in order to help diagnose and treat skeletal Class III malocclusion. METHODS: 100 adults and adolescents were divided into 5 groups according to age and occlusion. It consisted of 20 eases of adult normal occlusion, 20 youngster normal occlusion, 28 adult skeletal Class III malocclusion, 24 early skeletal Class III malocclusion, 8 early skeletal Class III malocclusion with treatment failure. Cephalometrie analysis was taken on lateral cephalograms including FH-PP, MP-AB, ODI. The data were analysed with SAS6.12 software package for grouped t test. RESULTS: The mean value of ODI in normal occlusion was above 70°. The average value of Class III malocclusion was less than 63°. All measurements in teenager were lower than those in adult. Severe malocclusions who need surgical treatment showed lower ODI value less than 53°. ODI displayed significant difference between groups, P<0.001. CONCLUSIONS: There is high correlation between ODI and severity of malocclusion. The results of this study demonstrate that ODI is an efficient index for evaluation of the vertical position of the skeletal Class III malocclusion. Supported by Shanghai Leading Academic Discipline Project (Grant No.Y0203). [ABSTRACT FROM AUTHOR]

PURPOSE: To evaluate and compare the morphology, and position of the glenoid fossa in patients with Class Il malocclusion associated with mandibular retrusion and Class I malocclusion in the permanent dentition. METHODS: A sample of 26 subjects (12 males, 14 females, average age 13.4 years) with skeletal and dental Class II malocclusion associated with mandibular retrusion, was compared with a matched group of 31 subjects(12 males, 19 females, aged 12.9 years) with skeletal and dental Class I relationships. The lateral cephalograms were traced and the cephalometric analysis was taken by Nemotec Dental Studio 2006 software before orthodontic treatment. The comparisons between the two groups on the cephalometric measures for the assessment of glenoid fossa were performed by means of an independent samples t test using SPSS 15.0 software package. The correlation and regression analysis was also performed within the measures in the Class II group. RESULTS: The results showed there was significant difference of Wits, GF/Ptm-FH and GF-FMN between the two groups (P<0.01). There was a significant correlation between the GF-FMN vs. AOBO, GF-FMN vs. GF/S- FH, GF/S-FH vs.GF/Ptm-FH, S/Ptm-FH vs. GF/Ptm-FH in the Class II group. The regression equations of the GF-FMN vs. AOBO and GF-FMN vs. GF/S-FH were also obtained (P<0.05). CONCLUSIONS: The Class II malocclusion associated with mandibular retrusion patients have a posteriorly displaced glenoid fossa compared with Class 1 patients. Cephaiometric measurement is a useful tool to evaluate the glenoid fossa morphology and position. Supported by Research Fund of Science and Technology Committee of Shanghai Municipality (Grant No.08DZ2271100). [ABSTRACT FROM AUTHOR]

PURPOSE: To investigate the relationship between sagittal upper airway size and craniofacial characteristics in men with malocclusion in early permanent dentition, and to find out the factor that affect the pharyngeal airway size remarkably. METHODS: Seventy-four cephalometric films of nonsnoring males with malocclusion aged from II to 16 years(mean 13 years) before treatment were collected and measured with Delaire cephalometric analysis, the results were assessed by SPSS13.0 software package, multiple regression analysis was used to examine the relationship between upper airway size anti craniofacial characteristics variation. RESULTS: The size of nasopharyngeal space (PNS-ad) correlated negatively with the upper face height, the inclination of ramus plane, percentage of cranial height to cranial base length. The size of palatopharyngeal space(Ve-PVe) correlated negatively with the upper face height, percentage of cranial height to cranial base length. The size of hypopharyngeal space (Ph1-Ph2) correlated positively with the angle between cervical vertebrae tangent and cranial base, negatively mandibular plane angle, the length of mandibular body and percentage of cranial height to cranial base length. CONCLUSIONS: The sagittal upper airway size of nonsnoring males with occlusion is significantly correlated to the craniofacial skeletal structures and head posture, the types of craniofacial growth and the skeletal structure around have remarkable effect on the upper airway space. Supported by Key Research Project of Bureau of Health of Chongqing Municipality (Grant No.05-1-007). [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that there is no difference between the effects of maxillary protraction on anterior crossbites in repaired unilateral cleft lip and palate (UCLP) and noncleft prepubertal boys. Materials and Methods: Eighteen operated UCLP boys with anterior crossbite (aged 9.54 ± 1.21 years) were the experimental subjects. Eighteen noncleft boys with similar malocclusion (aged 9.75 ± 1.46 years) were selected as a control group. A Hyrax appliance and reverse headgear were applied. Lateral cephalometric radiographs were taken before and after the treatment. Computerized cephalometric analysis and statistics were carried out. Results: There were no significant differences in anterior movement of point A between the two groups (P > .05). ANB increased by 3.82° and A-Pg (FH) increased by 5.89 mm in the UCLP group. ANB increased by 2.68° and A-Pg (FH) increased by 3.66 mm in the noncleft group. The change of sagittal skeletal intermaxillary relationships was significantly larger in the UCLP group than in the noncleft group (P < .05). The change of lower lip in the UCLP group was less than in the noncleft group (P < .05). Conclusions: The hypothesis is rejected. The changes of sagittal skeletal intermaxillary relationship and mandibular clockwise rotation were larger in the operated UCLP patients than in the noncleft subjects. The amount of the lower lip retrusion was significantly less in the UCLP patients. [ABSTRACT FROM AUTHOR]

The article presents a study to compare the characteristics of pseudo-Class III malocclusions with those of skeletal Class III malocclusions in Southern Chinese children with mixed or early permanent dentition. In this study, one group of children was included in the pseudo-Class III malocclusion and the other group was included in the skeletal Class III malocclusion. Analysis and results of the research were revealed.

Based on a literature review and recent surveys, the needs and implementation of preventive dentistry in China have been estimated. The average DMFT of 12- and 15-yr-old schoolchildren in Beijing were 1.61 and 2.11 respectively. The caries prevalence was higher in the coastal cities in the south. The caries rate was also higher in urban areas than in rural areas. There were some controversies in the results of fluoridation studies with one study reporting as high as 47.2% of the children to be afflicted with enamel fluorosis. The community periodontal disease status and treatment needs index (CPTNI) showed that 93% of the 12-yr-olds had bleeding, 98% had calculus and 15% had shallow pockets, with 100% of the children needing prophylaxis. There was a high prevalence of dental malocclusion with 54% of schoolchildren with dental anomalies, of whom 36% needed treatment. Much emphasis had been placed on oral pathology, oral medicine and maxillofacial surgery in the curriculum of Stomatology in Chinese dental schools. [ABSTRACT FROM AUTHOR]