Search

Introduction: Orthodontics in China has developed rapidly, but there is no standard index of treatment outcomes. We assessed the validity of the American Board of Orthodontics Objective Grading System (ABO-OGS) for the classification of treatment outcomes in Chinese patients., Methods: We randomly selected 108 patients who completed treatment between July 2005 and September 2008 in 6 orthodontic treatment centers across China. Sixty-nine experienced Chinese orthodontists made subjective assessments of the end-of-treatment casts for each patient. Three examiners then used the ABO-OGS to measure the casts. Pearson correlation analysis and receiver operating characteristic curve analysis were conducted to evaluate the correspondence between the ABO-OGS cast measurements and the orthodontists' subjective assessments., Results: The average subjective grading scores were highly correlated with the ABO-OGS scores (r = 0.7042). Four of the 7 study cast components of the ABO-OGS score-occlusal relationship, overjet, interproximal contact, and alignment-were statistically significantly correlated with the judges' subjective assessments. Together, these 4 accounted for 58% of the variability in the average subjective grading scores. The ABO-OGS cutoff score for cases that the judges deemed satisfactory was 16 points; the corresponding cutoff score for cases that the judges considered acceptable was 21 points., Conclusions: The ABO-OGS is a valid index for the assessment of treatment outcomes in Chinese patients. By comparing the objective scores on this modification of the ABO-OGS with the mean subjective assessment of a panel of highly qualified Chinese orthodontists, a cutoff point for satisfactory treatment outcome was defined as 16 points or fewer, with scores of 16 to 21 points denoting less than satisfactory but still acceptable treatment. Cases that scored greater than 21 points were considered unacceptable., (Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

This report describes the treatment of a 16-year-old girl with a severe transverse dental arch discrepancy resulting from a mildly constricted maxillary arch and an overexpanded mandibular arch. The patient had a Class I skeletal relationship, a high mandibular plane angle, a Class III molar relationship, bilateral posterior crossbites, and deviated midlines. A 3-dimensional digital setup was used to assist treatment planning. The digital setup allowed us to evaluate multiple treatment options before deciding on the most suitable one for the patient. The final treatment protocol consisted of extraction of upper second premolars and lower first molars due to enamel hypoplasia. Starting with the leveling and alignment stage of treatment, the maxillary archwires were expanded and the mandibular wires were constricted to correct the transverse discrepancy. An auxiliary expansion arch was used to achieve overcorrection. The active treatment period was 24 months. Proper overbite and overjet, facial balance, and good occlusion were achieved., (Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Objective: To analyze the results of multiple Chinese orthodontic specialists' subjective evaluation of orthodontic treatment outcome, to investigate the relevance of different experiment items and to explore the weight of each monomial material., Methods: As a randomized clinical trial, with six orthodontic treatment centers and Angle's classification being regarded as two stratification factors, it contained 108 cases with integrity data, which was random extracted from 2383 cases that received orthodontic treatment in six orthodontic treatment centers during the past five years, gathering post-treatment study casts, cephalometrics and photographs of 48 cases as the research subject. Similarly taking Angle's classification as a stratification factor, 108 cases were randomly divided into 9 groups. The randomization of sampling and grouping were both generated by a pseudo-random number generator. According to the monomial and combined subjects, 69 orthodontic specialists were regarded as the raters to rank the 12 cases in each group, and to judge whether the case was qualified., Results: Correlation analysis: the Spearman r between Post-M + C and Post-M + C + P and the Spearman r between Post-M + P and Post-M + C + P were both greater than 0.950. The Spearman r between Post-M and Post-P and the Spearman r between Post-M and Post-C were about 0.300. The Spearman r between Post-P and Post-C was 0.505. Regression analysis: the linear regression results: M + C = 0.782M + 0.308C - 0.150, M + P = 0.804M + 0.233P - 0.091, M + C + P = 0.764M + 0.243P + 0.131C - 0.291. The r(2) of above three models was greater than 0.9., Conclusions: It was applicable to use M + C and M + P instead of M + C + P. Study casts could not replace cephalometrics or photographs when doing subjective evaluation. Cephalometrics and photographs could not substitute for each other either. In the combined materials evaluation, model accounted for the largest percentage. Based on the regression model, for the greater part, the integration of several monomial materials could replace the combined material assessment effectively.

Objective: To investigate the agreement of subjective evaluation of orthodontic treatment outcome and to analyze possible factors that may be related to it., Methods: As a randomized clinical trial, with Angle's classification as a stratification factor, our study contained 48 cases with integrity data, which were randomly extracted from 806 orthodontic treatment cases in Peking University School and Hospital of Stomatology during July 2004 and August 2008, and gathered post-treatment study casts, cephalometrics and photographs of the 48 cases as the research subjects. Similarly with Angle's classification as a stratification factor, the 48 cases were randomly divided into 4 groups. According to the monomial and combined subjects, 12 clinicians were asked to act as the raters to rank the 12 cases in each group., Results: Overall, there were 1 584 pairings between the raters in the examination of evaluation. The mean Spearman r was 0.565 3 ± 0.239 9. Grouping factor was related to the agreement of subjective evaluation (P<0.05). In the third trial item-Post-M+P, the correlations were the greatest among the judge-pairs (P<0.001). The other five items were at the same agreement level. The level of orthodontic treatment outcome was a factor that influenced the agreement level of subjective evaluation (P<0.05). The score stability of the patients, whose treatment duration was longer than 2.5 years, was significantly higher than that of the patients whose treatment duration was between 1.5 years and 2.5 years (P<0.05). The following factors, such as Angle's classification, age of patients and whether the teeth was extracted or not, were the insignificant factors (P>0.05)., Conclusion: The average correlations present a moderate agreement level. Grouping, experimental item, the length of treatment duration and the level of orthodontic treatment outcome are the factors that affect the agreement of subjective evaluation. Several factors including Angle's classification, age of patients and whether the teeth is extracted or not, do not affect the agreement of subjective evaluation.

Objective: To investigate the craniofacial and occlusal changes of Class III cases treated with Tip-Edge Plus Technique., Methods: Thirteen Class III patients (6 girls and 7 boys, mean age 14.9 years) with mandibular protrusion were selected. All the patients were four premolar extraction cases and treated with Tip-Edge Plus technique. Cephalometric analysis was performed to evaluate the changes before and after treatment., Results: After treatment, Wits changed from (-2.50 +/- 1.40) mm to (-1.00 +/- 0.85) mm and ANB changed from (-0.61 +/- 1.41) degrees to (1.31 +/- 1.66) degrees (P < 0.05). UL-E and LL-E were decreased significantly from (7.55 +/- 1.24) mm to (4.82 +/- 1.05) mm and from (10.16 +/- 2.43) mm to (6.03 +/- 2.01) mm respectively (P < 0.01). The incisors were retracted. A remarkable soft tissue change was noted after the treatment. The difference between the distance of the upper lip and lower lip to SnPg' at the beginning of treatment changed from (-1.57 +/- 1.24) mm to (0.62 +/- 1.24) mm (P < 0.01). FCA changed from (2.62 +/- 1.53) degrees to (7.02 +/- 2.21) degrees ., Conclusions: With Tip-Edge Plus straight-wire technique and light continuous force, anterior teeth could be tipped distally and lingually quickly. The hard and soft tissues changed accordingly.

Introduction: This study continues our assessment of agreement and disagreement among 25 Chinese and 20 US orthodontists in the ranking for facial attractiveness of end-of-treatment photographs of randomly sampled growing Chinese and white orthodontic patients. The main aims of this article were to (1) measure the overall pattern of agreement between the mean rankings of US and Chinese orthodontists, and (2) measure the strength of agreement between the rankings of the US and Chinese orthodontists for each patient., Methods: Each judge independently ranked standard clinical sets of profile, frontal, and frontal-smiling photographs of 43 US patients and 48 Chinese patients. For each patient, a separate mean rank was computed from the responses of each group of judges. Pearson correlations between the mean ranks of the 2 groups of judges were used to measure their overall agreement. Paired and unpaired t tests were used to measure the agreement between the judges of the 2 groups for each patient., Results: The overall agreement between the mean rankings of the US and Chinese judges was very high. For the US patients, the correlation between the Chinese and US judges means was r = 0.92, P <0.0001. For the Chinese patients, the analogous value was r = 0.86, P <0.0001. Agreement between the 2 groups of judges concerning each patient was also generally strong. For two thirds of the patients, the mean ranks of the US and Chinese judges differed by less than 1 unit in a scale of 12. However, for 6 patients considered individually (5 Chinese and 1 US), the assessment of the 2 groups of judges was statistically significantly different at P values ranging from 0.02 to less than 0.0001, even after the Bonferroni correction., Conclusions: These findings demonstrate that orthodontic clinicians can reliably identify and rank subtle differences between patients, and that differences between judges and between patients can be distinguished at a high level of statistical significance, given appropriate study designs. However, the reasons clinicians give for the differences in their judgments are more difficult to investigate and will require further study.

Objective: To investigate hard-tissue changes in borderline cases with extraction and non-extraction during treatment and follow-up stages., Methods: Five associate professors, who were from Peking University School and Hospital of Stomatology, were asked to make judgment on the cases with full pre-treatment records for discriminating the borderline cases from extraction and non-extraction cases. Fifty-four borderline cases with full treatment records which had been out of treatment for at least 2 years were followed. Twenty-one cases with follow-up records were collected including 8 extraction cases and 13 non-extraction cases. Cephalometric measurements were preceded in IDAS (Image and Database Analysis System) software program., Results: In extraction group, significant changes of SNB, SNPg in A-P direction and that of ArGo/ANSMe, MP/SN in vertical direction were present during the follow-up stage, while the overjet was stable. In non-extraction group, only decrease of proclination of lower incisor and increase of overjet were present without any skeletal changes during the follow-up stage. In comparison of the two groups, no skeletal and dental changes showed statistically significant difference except for MP/SN and ArGoGn in pre-treatment stage, while dental characteristics in relation to upper and lower incisor (L1/NB, L1-NB, L1-AP, U1-AP, U1/L1) showed statistically significant difference between the two groups after treatment. But in follow-up stage, the skeletal and dental pattern tended to be similar for both groups only except for the proclination of lower incisor., Conclusion: The similarities of skeletal and dental pattern are demonstrated in extraction and non-extraction group before treatment. Dental changes are the major post-treatment changes in the two groups. In follow-up stage, counter-clockwise rotation of mandible is unique in extraction group, which is likely a helpful factor for stability of overjet, while lingual tipping of lower incisor in non-extraction group without skeletal changes may contribute to overjet relapse.

Objective: To evaluate the craniofacial and occlusional changes of Class II patients treated with Tip-Edge Plus technique., Methods: Twelve Class II patients (7 girls and 5 boys, mean age 14.3 years) with bimaxillary or maxillary protrusion were selected. All the patients were four first premolar extraction cases and treated with Tip-Edge Plus technique. Cephalometric analysis was performed to evaluate the changes before and after treatment., Results: After treatment, the profile was greatly improved. UL-E, LL-E were decreased significantly (P < 0.01) and incisors were retracted (P < 0.05). Upper molars moved forward slightly (P > 0.05)., Conclusions: The anchorage control in Tip-Edge Plus technique was effective without extraoral force, palatal arch and implants. Under very light force, the crown of anterior teeth tipped distally and lingually quickly. In the final stage, it was possible to achieve both desired root uprighting and crown torque.

Objective: The aim of the present study was to evaluate the long-term skeletal and dento-alveolar stability 15 years after combined orthodontic and surgical correction of skeletal anterior open bite., Patients and Methods: Ten (8 female, 2 male) anterior openbite patients who had undergone orthodontic treatment in combination with bimaxillary surgery at Hanover Medical School were examined. Each patient had undergone Le Fort I osteotomy combined with bilateral sagittal split osteotomy (BSSO); osteosynthesis with plates and screws was carried out in the maxilla, and wire-osteosynthesis in the mandible. Cephalometric records of these patients were examined immediately before the start of the orthodontic treatment (T1), before surgery (T2), immediately after surgery (T3), medium-term after surgery, averaging 1.5 years (T4), and long-term after surgery, averaging 15 years (T5). Hasund cephalometric analysis was performed for which skeletal and dental cephalometric measurements had been taken., Results: Moderate skeletal relapse was observed 15 years after surgery. Overbite remained quite stable 15 years after surgery, which is mainly due to the upper and lower incisors' eruption over the long-term period., Conclusion: Treatment of skeletal open bite via Le Fort I and bilateral sagittal split osteotomy appears to be a clinically successful procedure providing stable results.

Introduction: The purpose of this study was to compare orthodontic treatment outcomes in Chinese patients with borderline problems treated with and without extractions., Methods: Records of 39 borderline patients treated at the Faculty Clinic of the Peking University Orthodontic Department were evaluated retrospectively by 5 associate professors. Sixteen patients had been treated without extractions, and 23 had 4 first or second premolars extracted. Each judge evaluated the posttreatment records independently for tooth alignment, overbite, overjet, midline symmetry, lateral occlusion, and facial profile, and rated them on a scale from 1 to 5., Results: The only statistically significant difference between the extraction and nonextraction groups was for facial profile, with the judges preferring the extraction profiles. Fifteen soft-tissue cephalometric variables were measured to determine the source of the difference, and 6 showed statistically significant differences. When profile changes from pretreatment to posttreatment were examined, significant differences in treatment-associated changes between extraction and nonextraction groups were all related to the lower lip and chin., Conclusions: In this sample of Chinese borderline orthodontic patients, Chinese clinicians had a statistically significant preference for the facial profiles of the extraction patients, but no statistically significant preferences for tooth alignment, overbite, overjet, midline symmetry, or posterior occlusion. Extraction treatment increases the inclination of the chin and reduces protrusion of the lower lip compared with nonextraction treatment, and this might explain the difference.

Objective: Comparison of structural characteristic changes between deep overbite malocclusions with hyper- and hypodivergent skeletal pattern during treatment and follow-up stages. To discuss the difference between both in treatment mechanism and characteristic of relapse., Methods: 59 cases out of 162 finished patients with deep overbite malocclusion followed for more than 2 years, selected from orthodontic clinic in school of stomatology Peking University, were filtered by cephalometrics (MP-SN>40 degrees or <29 degrees)and then two groups were formed. The hyperdivergent group (MP-SN>40 degrees) comprised 10 cases and the hypodivergent group (MP-SN<29 degrees) comprised 9 cases. Measurements and statistics were performed upon the two groups., Results: After orthodontic treatment, the hyperdivergent group exhibited the extrusions of upper and lower molars [U6-PP increased from (10.69+/- 2.10)mm to (12.91+/-2.19)mm; L6-MP increased from (17.34+/-2.73)mm to (20.86+/-3.08)mm]. As to the skeletal change, a decrease of ANB angle from (5.86+/- 1.34) degrees to (4.62+/-1.67) degrees and NA-PA angle from (11.99+/-3.74) degrees to (8.76+/-4.45) degrees reflecting the sagittal change tendency from skeletal Class II to Class I. In vertical direction, the ratio of Ar-Go/ANS-Me increased from (0.58+/-0.03) to (0.62+/-0.05). Compared with the hyperdivergent group, the hypodivergent one only showed the extrusion of lower molars after treatment. The stability of overbite didn't show any statistically significant difference between two groups during the follow-up stage. Also in this stage the change of overbite in the hyperdivergent group was mainly due to the lingual inclination of upper incisors during the treatment stage and in the hypodivergent group it was due to the molar extrusion during treatment., Conclusion: The ramus showed great potential of growth in the hyperdivergent group during the treatment stage, which maintained the inclination of mandibular plane. The relapse of overbite was correlated with the changes of teeth during the treatment and follow-up stages.

Objective: To compare soft-tissue morphology changes by cephalometric measurements between extraction and non-extraction orthodontic treatment in borderline cases., Methods: The samples consisted of 33 cases selected as borderline cases by 5 orthodontic specialists. They were divided into 21 extraction cases (including 13 four first premolar extraction cases and 8 four second premolar extraction cases) and 12 non-extraction cases by checking patients' treatment records. Conventional cephalometric analysis was made to compare soft tissue structures before and after orthodontic treatments and the same comparison was made between two different extraction patterns., Results: No statistical difference was found in pretreatment soft-tissue morphology between extraction and non-extraction groups divided from borderline cases. The PosBs/FH of the four first premolars extraction group was smaller than that of non-extraction group, and the Ns-Sn-Pos of the four first premolars extraction group was smaller than that of four second premolar extraction group. None of the post-treatment soft-tissue measures showed significant statistical differences between four first premolars extraction group and non-extraction group, but there were 6 items showed significant statistical differences between four second premolars extraction group and non-extraction group. Compared with extraction and non-extraction treatments, the most significant soft-tissue changes were: PosBs/FH, LL-SnPos, and Bs-EP ., Conclusion: Although pre-treatment soft-tissue morphology of second premolar extraction group was close to that of non-extraction group, the post-treatment soft-tissue morphology of first premolar extraction group became closer to that of non-extraction group. Compared with non-extraction treatment, the more significant changes caused by extraction treatment were located in the lower lip and chin, but not the upper lips.

Objective: To compare the treatment effect on the prominence of profile in borderline cases between extraction and non-extraction treatment., Methods: The sample consisting of 33 borderline cases based on the judgment of 5 orthodontic specialists was divided into three groups according to the treatment way selected by the doctor in charge of the case. Three groups comprised 12 non-extraction cases, 13 four first premolars extraction cases and 8 four second premolars extraction cases. Structure superimposition was used to measure landmarks displacements which reflect the change of profile prominence before and after orthodontic treatment using pretreatment FH plane as a frame of reference., Results: Only the prominence of upper and lower incisors showed statistically significance between the extraction and non-extraction treatments. There was no statistically significant difference between the extraction of four first premolars and second premolars., Conclusion: The main effect of extraction vs. non-extraction on profile of borderline cases is the prominence of upper and lower incisors, while their influences on upper and lower base bone and soft-tissue profile are not obvious.

Objective: To investigate the relapse of incisor alignment after orthodontic treatment and possible factors which may related to its stability., Methods: 72 finished cases with full records selected from orthodontic clinic of Peking University School of Stomatology composed the sample. The follow-up lateral head films and study casts were taken at least 2 years after orthodontic treatment. The cephalograms were measured by computerized program and the study casts measured by caliper., Results: The upper Irregularity Index decreased from (11.5 +/- 5.02) mm before treatment to (2.01 +/- 1.39) mm after treatment and then increased to (3.46 +/- 1.69) mm in the follow-up stage. The lower Irregularity Index decreased from (7.24 +/- 44.35) mm before treatment to (1.75 +/- 1.04) mm after treatment and then increased to (3.39 +/- 1.78) mm in the follow-up stage. The changes are significant statistically. The changes of jaw in the sagittal and vertical directions as well as the related changes of the position of lower incisors, the decrease of the lower canine arch width, Bolton Index and sex all have statistically significant relation with the changes of the lower Irregularity Index after retention., Conclusions: Compared with lower arch, the alignment in upper arch is more stable in the follow-up stage. The results suggest that some possible factors may have correlations with the change of lower arch crowding during the follow-up stage.

The authors made a thorough and careful study on the Begg Stage I appliance and established a model of mechanics in accordance with the actual situation of arch wire being activated and derived a mathematical formula based on the elastic small deflection theory. This study provides not only the basis of choosing intrusive-force value for individual arches, but also the possibility of analysing dynamically the changes of intrusive- force value in the process of bite opening.

Class II elastics are usually employed in the treatment of excessive overbite and overjet with the Begg technique. The effect of Class II elastics on bite opening and the extent of such an effect is uncertain. This article, based on measurements of 30 cases, illustrates that the effect of the vertical component of force from Class II elastics in reducing the intrusive force generated by the anchor bands in the upper archwire is less than previously believed. The position of the circles in the archwire for intermaxillary elastics has the greatest influence on the anterior intrusive force of the upper archwire. The direction of the Class II elastics and the length of the dental arch (a negative correlation) came second, while the force actually exerted by the elastics had the smallest influence. It is, therefore, suggested that the position of the intermaxillary elastic circles should be located according to the differing clinical objectives.