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This study aimed to evaluate the differential positional changes of the proximal and distal segments during mandibular setback surgery relapse. Thirty patients with mandibular prognathism who underwent bilateral sagittal split ramus osteotomy were included. Skull models from pretreatment, postsurgery, and post-treatment cone-beam computed tomography were superimposed to evaluate condylar displacement and rotational changes, and to determine the center of rotation (CRot) in the proximal and distal segments. During postsurgical relapse, the proximal segment rotated 2.4 ± 2.1° counterclockwise, with the CRot located near the mandibular condyle. The distal segment rotated 2.0 ± 2.3° counterclockwise, resulting in forward and upward movement of the chin. The displaced condyle partially returned to its original position during postsurgical orthodontic treatment. A vertical bony step (VBS) between the proximal and distal segments commonly occurs during mandibular setback surgery. As the VBS increases, the CRot of the distal segment shifts posterosuperiorly, following a predictable pattern outlined by regression equations. These findings suggest that relapse after mandibular setback surgery consistently occurs in an anterosuperior direction, with translatory movement becoming more prominent as the VBS increases. Including these regression equations in presurgical planning can enhance the precision of relapse simulations and help clinicians more accurately anticipate postsurgical relapse. [ABSTRACT FROM AUTHOR]

Class III malocclusion prevalence varies significantly among racial groups, with the highest prevalence observed in southeast Asian populations at 15.80%. These malocclusions often involve maxillary retrognathism, mandibular prognathism, or both, accompanied by maxillary constriction and crossbites. Comprehensive treatment should address anteroposterior, transverse, and vertical imbalances. Microimplant-assisted rapid palatal expansion (MARPE) has shown high success rates for transverse maxillary expansion in late adolescents and adults, presenting a viable alternative to surgically-assisted rapid palatal expansion (SARPE). This case report aims to demonstrate the successful treatment of a young adult female with borderline Class III malocclusion using MARPE and mandibular backward rotation (MBR) techniques. A 21-year-old female presented with a Class III skeletal pattern, anterior/posterior crossbites, and mild dental crowding. Despite her concerns about a concave facial profile, the patient declined orthognathic surgery due to a negative experience reported by a friend. The treatment plan included MARPE to correct maxillary transverse deficiency and MBR to alleviate Class III malocclusion severity. Lower arch distalization was performed using temporary anchorage devices (TADs) on the buccal shelves, and Class II elastics were used to maintain MBR and prevent retroclination of the lower labial segment during anterior retraction. Significant transverse correction was achieved, and the severity of Class III malocclusion was reduced. The lower dentition was effectively retracted, and the application of Class II elastics helped maintain MBR. The patient's final facial profile was harmonious, with well-aligned dentition and a stable occlusal relationship. The treatment results were well-maintained after one year. The MARPE with MBR approach presents a promising alternative for treating borderline Class III cases, particularly for patients reluctant to undergo orthognathic surgery. This case report highlights the effectiveness of combining MARPE and MBR techniques in achieving stable and satisfactory outcomes in the treatment of Class III malocclusion. [ABSTRACT FROM AUTHOR]

Patients with class III malocclusion often exhibit mandibular prognathism and complain of "prognathic appearance". The overall positive effects of orthognathic surgery on facial appearance have been demonstrated using patient-reported outcome measures (PROMs), but studies investigating the correlation between subjective PROMs results and objective measurements of imaging studies are sparse in the literature. This study recruited consecutive patients with skeletal class III malocclusion who underwent two-jaw orthognathic surgery between January 2016 and January 2021. The PROMs survey was conducted focusing on subjective perception of mandibular appearance. Lateral cephalometric images were measured to examine the correlation with the PROMs results. A total of 96 patients were eligible for this study. Of these, 74 patients (77.1%) reported complete correction of prognathic appearance postoperatively, whereas 22 patients (22.9%) perceived residual prognathic appearance. In a comparison of postoperative measurements between completely and incompletely satisfied patients, there were significant differences in SNB, ANB, convexity, facial angle, Nv-B, Nv-Pog, SN'B', soft tissue facial angle, lip–chin–throat angle, N'v-B′, and N'v-Pog'. The PROM results were significantly associated with the objective measurements of imaging studies. Investigating the correlation between PROMs and objective measurements enables integration of patients' perception of the outcomes into future therapeutic strategy and surgical planning, contributing to the enhancement of patient satisfaction. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this retrospective study was to determine orthognathic surgery indicators for Japanese patients with jaw deformities using both Index of Orthognathic Functional Treatment Needs (IOFTN) and maxillofacial morphometric analysis. Subjects and methods: The subjects were 89 patients treated with orthognathic surgery and 92 patients treated with orthodontic treatment alone, and were classified as class I, II, or III according to the ANB angle. Based on the results for IOFTN and the results of cephalometric analysis, the indication criteria for orthognathic surgery were examined. Results: In IOFTN analysis, none of patients in the orthognathic surgery group were classified as category 1 or 2, while 48% of the patients in the orthodontic treatment group were classified as category 4 or 5. The results of the cephalometric analysis of patients in classified categories 4 and 5 showed that the orthognathic surgery group had significantly greater lateral mandibular deviation in Class I cases, significantly more severe degree of mandibular retrusion in Class II cases, and significantly more severe degree of mandibular prognathism in Class III cases. The results of the logistic regression analysis showed that IOFTN was a common variable as an indication criterion for orthognathic surgery, and several different variables were also selected from the cephalometric measurements in each group. Conclusion: IOFTN is a highly sensitive and useful indicator as a criterion for orthognathic surgery. However, in the choice of treatment strategy, maxillofacial morphometric analyses and the patient's desired goal are important. [ABSTRACT FROM AUTHOR]

Background: Coordination among lip, cheek and tongue movements during swallowing in patients with mandibular prognathism remains unclear. Objectives: This study aimed to identify the temporal sequences of tongue pressure and maxillofacial muscle activities during swallowing in patients with mandibular prognathism and compared characteristics with those of healthy volunteers. Methods: Seven patients with mandibular prognathism (mandibular prognathism group) and 25 healthy volunteers with individual normal occlusion (control group) were recruited. Tongue pressures and masseter, orbicularis oris, mentalis and supra‐ and infrahyoid muscle activities while swallowing gel were measured simultaneously using a sensor sheet system with five measurement points and surface electromyography, respectively. Onset time, offset time and durations of tongue pressure and muscle activities were analysed. Results: In the mandibular prognathism group, tongue pressure was often produced first in more peripheral parts of the palate. Offset of tongue pressure in the posteromedian and peripheral parts of the palate and maxillofacial muscle activities except for orbicularis oris were delayed. Duration of tongue pressure in the anteromedian part of the palate was significantly shorter and durations of masseter, mentalis and suprahyoid muscle activities were significantly longer. Times to onset of orbicularis oris and suprahyoid muscle activities based on first onset of tongue pressure were significantly shorter. Conclusion: These results suggest that patients with mandibular prognathism may exhibit specific patterns of tongue pressure production and maxillofacial muscle activities during swallowing. [ABSTRACT FROM AUTHOR]

We present a case report of a 26-year-old female suffering from Coffin–Siris Syndrome, who underwent orthodontic treatment and surgery to solve her malocclusion and to improve her aesthetics and functional occlusion. Methods: The presurgical phase involved multibracket self-ligating attachments, namely a Damon prescription. The patient underwent maxillofacial surgery to correct the severe skeletal malocclusion and to relocate the bone bases to the right position. Post-surgical orthodontic treatment was performed to complete the alignment. Results: The patient's aesthetics and functional abilities improved. Conclusions: Syndromic patients can undergo orthodontic treatment if comorbidities and collaboration allow it. The support and collaboration of families and psychotherapists must be considered, but clinical cases of syndromic patients can be faced and solved. Obviously, each syndromic patient is considered unique, and the risk–benefit ratio must be correctly assessed for each one. [ABSTRACT FROM AUTHOR]

The extent of three-dimensional soft tissue changes in patients with varied facial skeletal patterns following mandibular setback surgery remains unclear. In this study, we aimed to investigate the postoperative changes in soft tissue chin thickness among mandibular prognathism patients, focusing on those presenting different divergence patterns, such as hyperdivergent and normodivergent patients. Cone-beam computed tomography images were obtained from 56 skeletal Class III patients who underwent only mandibular setback. Based on vertical craniofacial skeletal relationship, patients were divided into normodivergent group (27°37°) group. The three-dimensional displacements of Infradentale (Id), B point (B), and Pogonion (Pog), the soft tissue thickness of Id-Li (Labrale inferius), B-B' (soft tissue B point), and Pog-Pog' (soft tissue Pog point) were measured. Factors influencing the change in soft tissue thickness were investigated. Preoperative B-B' and Pog-Pog' thickness were significantly thinner in the hyperdivergent group than normodivergent group. Postoperative changes in B-B' and Pog-Pog' thickness were significantly larger in the hyperdivergent group than normodivergent group. A significant correlation was found between soft tissue thickness change (B-B' and Pog-Pog') and the preoperative soft tissue thickness and superior movement (B and Pog). Hyperdivergent patients with skeletal class III have thinner preoperative soft tissue thickness (B-B' and Pog-Pog') than normodivergent patients in the preoperation. Postoperative changes in B-B' and Pog-Pog' thickness were significantly larger in the hyperdivergent group than normodivergent group. Postoperative superior movement of B and Pog correlated with postoperative change of soft tissue thickness. [ABSTRACT FROM AUTHOR]

Purpose: This study compared sequential changes in skeletal stability and the pharyngeal airway following mandibular setback surgery involving fixation with either a titanium or a bioabsorbable plate and screws. Materials and Methods: Twenty-eight patients with mandibular prognathism undergoing bilateral sagittal split osteotomy by titanium or bioabsorbable fixation were randomly selected in this study. Lateral cephalometric analysis was conducted preoperatively and at 1 week, 3-6 months, and 1 year postoperatively. Mandibular stability was assessed by examining horizontal (BX), vertical (BY), and angular measurements including the sella-nasion to point B angle and the mandibular plane angle (MPA). Pharyngeal airway changes were evaluated by analyzing the nasopharynx, uvula-pharynx, tongue-pharynx, and epiglottis-pharynx (EOP) distances. Mandibular and pharyngeal airway changes were examined sequentially. To evaluate postoperative changes within groups, the Wilcoxon signedrank test was employed, while the Mann-Whitney U test was used for between-group comparisons. Immediate postoperative changes in the airway were correlated to surgical movements using the Spearman rank test. Results: Significant changes in the MPA were observed in both the titanium and bioabsorbable groups at 3-6 months post-surgery, with significance persisting in the bioabsorbable group at 1 year postoperatively (2.29°±2.28°; P<0.05). The bioabsorbable group also exhibited significant EOP changes (-1.21±1.54 mm; P<0.05) at 3-6 months, which gradually returned to non-significant levels by 1 year postoperatively. Conclusion: Osteofixation using bioabsorbable plates and screws is comparable to that achieved with titanium in long-term skeletal stability and maintaining pharyngeal airway dimensions. However, a tendency for relapse exists, especially regarding the MPA. [ABSTRACT FROM AUTHOR]

Patient-specific 3D models of the human mandible are finding increasing utility in medical fields such as oral and maxillofacial surgery, orthodontics, dentistry, and forensic sciences. The efficient creation of personalized 3D bone models poses a key challenge in these applications. Existing solutions often rely on 3D statistical models of human bone, offering advantages in rapid bone geometry adaptation and flexibility by capturing a range of anatomical variations, but also a disadvantage in terms of reduced precision in representing specific shapes. Considering this, the proposed parametric model allows for precise manipulation using morphometric parameters acquired from medical images. This paper highlights the significance of employing the parametric model in the creation of a personalized bone model, exemplified through a case study targeting mandibular prognathism reconstruction. A personalized model is described as 3D point cloud determined through the utilization of series of parametric functions, determined by the application of geometrical morphometrics, morphology properties, and artificial neural networks in the input dataset of human mandible samples. With 95.05% of the personalized model's surface area displaying deviations within −1.00–1.00 mm relative to the input polygonal model, and a maximum deviation of 2.52 mm, this research accentuates the benefits of the parametric approach, particularly in the preoperative planning of mandibular deformity surgeries. [ABSTRACT FROM AUTHOR]

Objective: To investigate orofacial traits and general factors related to oral health‐related quality of life in acromegaly patients. Materials and Methods: A cross‐sectional study with 34 acromegaly patients was conducted. The OHIP‐14 questionnaire was used to assess oral health‐related quality of life scores. To assess orofacial and occlusion morphology, an oral evaluation was performed. Correlation measures, multiple linear regression and a structural equation model (SEM) were used in the statistical analysis. Results: The presence of arthrosis (SC = 0.467, SE = 0.155, p = 0.003) and smoking history (SC = 0.459, SE = 0.206, p = 0.026) were associated with a negative impact on oral health‐related quality of life. Mandibular protrusion was related to physical pain (β = 2.74, p = 0.029). Anterior open bite (β = 4.44, p = 0.004) and anterior crossbite (β = 2.61, p = 0.026) were related to psychological disability. Diastema was related to social disability (β = 3.42, p = 0.037) and handicap (β = 2.74, p = 0.044). Conclusion: The findings suggest that smoking, arthrosis and orofacial alterations (mandibular protrusion, open bite, crossbite and diastema) have a negative impact on oral health‐related quality of life in acromegaly patients. [ABSTRACT FROM AUTHOR]

This systematic review aimed to investigate the factors that may contribute to the development of OSA after orthognathic surgery in patients with skeletal class III. Electronic searches of PubMed, Embase, Web of Science, and Cochrane databases were conducted up to December 10, 2022. In total, 277 studies were retrieved and screened according to the inclusion and exclusion criteria, and 14 were finally selected. All studies were of medium quality (moderate risk of bias). The occurrence of OSA after orthognathic surgery in patients with class III skeletal relationships depends on surgical factors and patient self-factors. Surgical factors include surgery type, amount of maxillary and mandibular movement, and the patient's postoperative swelling. Patient self-factors include weight, age, gender, and hypertrophy of the soft palate, tonsils, and tongue. According to information in the 14 selected articles, the incidences of OSA after Le Fort I impaction and BSSO setback, BSSO setback, and Le Fort I advancement and BSSO setback were 19.2%, 8.57%, and 0.7%, respectively, mostly accompanied with greater amounts of mandibular recession. However, no clear evidence exists to confirm that orthognathic surgery is a causative factor for postoperative sleep breathing disorders in patients with mandibular prognathism. The wider upper airway in patients with class III skeletal might be the reason for the rare occurrence of OSA after surgery. In addition, obesity and advanced age may lead to sleep apnea after orthognathic surgery. Obese patients should be advised to lose weight preoperatively. [ABSTRACT FROM AUTHOR]

In addition to affecting oral functions such as temporomandibular joint function, mastication, and speech, malocclusion caused by skeletal maxillary prognathism also entails sociopsychological implications. Surgical orthodontic treatment to improve occlusion and oral function and to correct esthetic disharmony is important to improve patients' quality of life. We report the case of a 32-year-old woman who visited our hospital with a chief complaint of proclined upper front teeth. Clinical examination revealed maxillary overgrowth and severe labial inclination of the maxillary incisors with palatal gingival recession. The incisal protrusion was corrected with a maxillary anterior alveolar osteotomy—a surgical orthodontic method that could improve the overbite without causing excessive lingual inclination, while also minimizing orthodontic movement of the maxillary anterior teeth. This treatment is generally indicated in cases of maxillary prognathism with a relatively stable occlusal relationship in the molar region. As a result of the treatment, the patient's chief complaint improved and a long-term functional occlusion was achieved. This paper outlines the pre- and posttreatment skeletal and occlusal changes. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the differential positional changes of the proximal and distal segments during mandibular setback surgery relapse. Thirty patients with mandibular prognathism who underwent bilateral sagittal split ramus osteotomy were included. Skull models from pretreatment, postsurgery, and post-treatment cone-beam computed tomography were superimposed to evaluate condylar displacement and rotational changes, and to determine the center of rotation (CRot) in the proximal and distal segments. During postsurgical relapse, the proximal segment rotated 2.4 ± 2.1° counterclockwise, with the CRot located near the mandibular condyle. The distal segment rotated 2.0 ± 2.3° counterclockwise, resulting in forward and upward movement of the chin. The displaced condyle partially returned to its original position during postsurgical orthodontic treatment. A vertical bony step (VBS) between the proximal and distal segments commonly occurs during mandibular setback surgery. As the VBS increases, the CRot of the distal segment shifts posterosuperiorly, following a predictable pattern outlined by regression equations. These findings suggest that relapse after mandibular setback surgery consistently occurs in an anterosuperior direction, with translatory movement becoming more prominent as the VBS increases. Including these regression equations in presurgical planning can enhance the precision of relapse simulations and help clinicians more accurately anticipate postsurgical relapse.

Late-onset Pompe disease manifests predominantly in the proximal lower limbs and may be mistaken for an inflammatory myopathy. A 46-year-old man with acromegaly had an 8-year history of progressive weakness. His myopathy was initially attributed to the acromegaly, but severe progression prompted a muscle biopsy, which suggested an inflammatory myopathy. However, his weakness progressed despite treatment for polymyositis. His muscle ultrasound scan pattern was more suggestive of Pompe disease than polymyositis, and Pompe disease was confirmed by genetic and enzymatic testing. Patients with apparent polymyositis, which persists despite treatment, require reconsideration of the diagnosis, with particular attention to treatable genetic causes. [ABSTRACT FROM AUTHOR]

This study measured and analyzed chronological changes in temporomandibular joint space volume by compartment following transoral vertical ramus osteotomy (TOVRO) using reconstructed 3-dimensional (3D) images of patients with mandibular prognathism. It included 70 joints of 35 patients who underwent TOVRO between January 2018 and December 2021. Computed tomography (CT) or cone-beam CT (CBCT) was performed before surgery (T0) and at 3 days (T1), 6 months (T2), and 12 months postoperatively (T3). These scans were then analyzed using 3D software. The volumes of the overall (Vjs), anterior (Vajs), posterior (Vpjs), medial (Vmjs), and lateral (Vljs) joint spaces were calculated at each time point. A linear mixed model and repeated-measures covariance pattern with unstructured covariance were used to evaluate significant changes in joint space volume over time. Vjs significantly increased to 134.54 ± 34.28 mm3 at T3 compared to T0 (p < 0.001). Vpjas and Vljs increased by 130.72 ± 10.07 mm3 and 109.98 ± 7.52 mm3 at T3 compared to T0, respectively (p < 0.001). However, no significant difference was observed between T0 and T2 in Vajs and Vmjs (p = 0.9999). The observed volume increases in Vpjs and Vljs appeared to contribute to the overall Vjs increase. [ABSTRACT FROM AUTHOR]

Facial asymmetry is often seen in patients with skeletal mandibular prognathism and is associated with deformities in the maxillofacial and head regions. The maxillofacial deviation is three-dimensional and affects not only the lateral deviation of the mandible and midface, but also the cranium. This study conducted a three-dimensional morphological evaluation of the cranial base morphology of patients with skeletal mandibular prognathism (ANB < 0°, Wits < 0 mm) with the aim of examining the relationship between deformities of the head region and facial asymmetry. Data obtained from computed tomography conducted during the initial examination of patients with and without skeletal mandibular prognathism with facial asymmetry were used. Differences in the position of structures present in the cranial base were measured, and the association between cranial deformities and mandibular deviation was assessed. The middle cranial base area and the lateral deviation of the mandibular fossa were significantly larger in patients with facial asymmetry compared to those without facial asymmetry. In addition, a correlation between the amount of mandibular deviation and the area of the anterior cranial base was identified in patients with significant cranial deformity (p = 0.012). Given the identified association between the structure of the head region and facial asymmetry, further studies are needed to determine the factors implicated in the growth process. [ABSTRACT FROM AUTHOR]

Mandibular prognathism is a gnathic defect that causes severe dysfunction of the stomatognathic system. The aim of the study was to describe the compensatory mechanisms in the anatomical structure of the historical skull of a woman with severe mandibular prognathism, from the 'Kuronia' collection from the former 19th-century cemeteries of the Evangelical-Reformed Parish and the Evangelical-Augsburg Parish of St. Mary Magdalene in Wrocław. The compensatory changes in the anatomical structure of the skull, mainly affecting the alveolar part of the mandible and the maxillary alveolar processes, were probably aimed at achieving functionally efficient interdental contacts in the upper and lower arches. Due to edentulism, it was not possible to describe the exact position of the teeth. However, from the preserved alveolar bone structures it was possible to approximate the axes of their inclination. The analysis of the defects of the stomatognathic system in historical populations can enrich the study of their biological condition, constituting a rich source of information on their lifestyle and nutrition. [ABSTRACT FROM AUTHOR]

Introduction: Mandibular prognathism, also called progenia, is a type of anterior malocclusion that has negative effects on physical and mental health. The aim of the study was to determine differences in the selfimage of people with mandibular prognathism before and after orthognathic surgery. Materials and methods: The study included 155 people - 79 of whom had a mandibular prognathism (group A) and 76 of whom had a previous mandibular prognathism that had already been corrected by surgery (group B). The research method used was a diagnostic survey that included original questions about wellbeing, self-esteem, and self-confidence. Results: Group A statistically significantly more often experienced feelings of frustration, lower self-confidence, embarrassment, concern about appearance, especially when meeting new people, and lack of comfort due to their appearance being the center of attention than group B. People in group A were statistically significantly more likely to avoid smiling or laughing in company, to hide a smile in pictures, to avoid looking at themselves in the mirror, to compare their appearance to others, and to avoid meetings due to dissatisfaction with their appearance than were people in group B. People in group A were statistically significantly less likely to preferably rate the general appearance of the face, the profile of the face, the appearance of the face from the front, and the appearance of the teeth than were people in group B. People in group A were statistically significantly less likely to preferably rate the general appearance of the face, the profile of the face, the appearance of the face from the front, and the appearance of the teeth than were people in group B. Conclusions: Orthognathic surgery is a very important factor affecting the psyche of people with prognathism. People with mandibular prognathism before orthognathic surgery experience more negative feelings about their appearance, more often engage in behaviors aimed at concealing a malocclusion, and rate their appearance worse than people who have undergone orthognathic surgery. In view of this, comprehensive medical care, including psychological care, should be provided before, during, and after surgery. [ABSTRACT FROM AUTHOR]

We present a case report of a 26-year-old female suffering from Coffin–Siris Syndrome, who underwent orthodontic treatment and surgery to solve her malocclusion and to improve her aesthetics and functional occlusion. Methods: The presurgical phase involved multibracket self-ligating attachments, namely a Damon prescription. The patient underwent maxillofacial surgery to correct the severe skeletal malocclusion and to relocate the bone bases to the right position. Post-surgical orthodontic treatment was performed to complete the alignment. Results: The patient’s aesthetics and functional abilities improved. Conclusions: Syndromic patients can undergo orthodontic treatment if comorbidities and collaboration allow it. The support and collaboration of families and psychotherapists must be considered, but clinical cases of syndromic patients can be faced and solved. Obviously, each syndromic patient is considered unique, and the risk–benefit ratio must be correctly assessed for each one.

Background: The relationship between the maximum lip‐closing force (LCF) and malocclusion has long been studied. Recently, a method to measure the ability to control directional LCF from eight directions (upper, lower, right, left and the four directions in between) during lip pursing was established. Objective: It is considered important to evaluate the ability to control directional LCF. The aim of this study was to investigate the ability of skeletal class III patients to control directional LCF. Methods: Fifteen skeletal class III patients (mandibular prognathism group) and 15 people with normal occlusion (normal occlusion group) were recruited. The maximum LCF and the accuracy rate (the ratio of the matched time in which the participant was able to keep the LCF in the target range over a total time of 6 s) were measured. Results: The maximum LCF was not significantly different between the mandibular prognathism group and the normal occlusion group. The accuracy rate in the mandibular prognathism group was significantly lower in all six directions than that in the individual normal occlusion group. Conclusion: As the accuracy rate in all six directions was significantly lower in the mandibular prognathism group than that in the normal occlusion group, occlusion and craniofacial morphology might influence lip function. [ABSTRACT FROM AUTHOR]

Arch forms in orthodontics are considered to affect occlusal stability. This study's subjects were 47 patients (Class III S group) who visited the Chiba Dental Center of Tokyo Dental College and were surgical orthodontic cases, and 60 patients with Class I malocclusion were selected as the control group. A mandibular model of each subject was plotted with each tooth on a digitizer. The clinical bracket points of each tooth were plotted, and intercanine and intermolar measurements were taken. The least squares method was used to fit a quartic equation, and the arch form was drawn. The Class IIIS group was divided by Wits appraisal and facial pattern into a dolichofacial or brachyfacial pattern, and arch forms were compared. The results show that the Class IIIS group had a significantly smaller intermolar width, canine depth, and molar depth and a significantly larger canine W/D ratio. In those with a dolichofacial pattern, the anterior curve of the arch form tended to be flat and the posterior curve narrower. This is because, in skeletal mandibular prognathism, the mandibular anterior shows lingual tipping, and the molars show palatal tipping due to dental compensation, and it was inferred that this tendency was higher in high-angle cases. [ABSTRACT FROM AUTHOR]

This review examines a prevalent condition with multifaceted etiology encompassing genetic, environmental, and oral behavioral factors. It stands as a significant ailment impacting oral functionality, aesthetics, and quality of life. Longitudinal studies indicate that malocclusion in primary dentition may progress to permanent malocclusion. Recognizing and managing malocclusion in primary dentition is gaining prominence. The World Health Organization ranks malocclusions as the third most widespread oral health issue globally. Angle's classification system is widely used to categorize malocclusions, with Class I occlusion considered the norm. However, its prevalence varies across populations due to genetic and examination disparities. Genetic factors, including variants in genes like MSX1, PAX9, and AXIN2, have been associated with an increased risk of Class I occlusion. This review aims to provide a comprehensive overview of clinical strategies for managing Class I occlusion and consolidate genetic insights from both human and murine populations. Additionally, genomic relationships among craniofacial genes will be assessed in individuals with Class I occlusion, along with a murine model, shedding light on phenotype–genotype associations of clinical relevance. The prevalence of Class I occlusion, its impact, and treatment approaches will be discussed, emphasizing the importance of early intervention. Additionally, the role of RNA alterations in skeletal Class I occlusion will be explored, focusing on variations in expression or structure that influence craniofacial development. Mouse models will be highlighted as crucial tools for investigating mandible size and prognathism and conducting QTL analysis to gain deeper genetic insights. This review amalgamates cellular, molecular, and clinical trait data to unravel correlations between malocclusion and Class I phenotypes. [ABSTRACT FROM AUTHOR]

This case presents a facially mature patient with Beckwith–Wiedemann Syndrome (BWS) who presented with severe class III malocclusion. Computed tomography imaging revealed an anterior crossbite of 19 mm and a narrow pharyngeal airway at the level of the tongue base precluding mandibular setback surgery. The patient was indicated for a LeFort III combined with a LeFort I advancement, each of 10 mm, for a 20 mm combined advancement. Stable, functional occlusion was achieved without airway compromise. This novel use of the combined LeFort III/I can restore stable class I occlusion in patients with BWS at risk for tongue base airway compromise. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the changes in the upper airway following mandibular setback surgery. Methods: The patients underwent mandibular setback surgery and cone‐beam computed tomography scan data obtained at four time points: before surgery, immediately after surgery, short‐ and long‐term follow‐up. Upper airway geometries were segmented and extracted at each time point. Time‐averaged airflow through the upper airway was evaluated at each time point. The measurements of airway volume and minimum cross‐sectional areas were obtained at four time points. Results: The airway volume and cross‐sectional areas of airway significantly decreased immediately after surgery (p = 0.013 for airway volume and 0.016 for cross‐sectional area). At short‐term follow‐up, the decreased airway volume and cross‐sectional areas still showed statistically significant difference to original dimension (p = 0.017 for airway volume and 0.006 for cross‐sectional area). At long‐term follow‐up, although there were no statistical significances (p = 0.859 for airway volume and 0.721 for cross‐sectional area), the airway volume and cross‐sectional areas had increased slightly compared to those at short‐term follow‐up. Conclusions: Although the airflow and dimensional parameters of the upper airway worsened following mandibular setback surgery, there was a tendency to gradually recover during long‐term follow‐up. [ABSTRACT FROM AUTHOR]

With the advancement of digital technology over the last few decades, the use of virtual surgical planning and fabrication of surgical guides have tremendously improved the outcomes of various maxillofacial surgical procedures. The intraoral vertical ramus osteotomy (IVRO) is an orthognathic surgical procedure largely employed for mandibular setback in correcting dentofacial deformities. This study describes the design and application of a surgical cutting guide for IVRO. The guide can also be used to facilitate the placement of miniplate fixation. The initial experience at the authors' centre suggests that the guide has allowed the osteotomy to be performed with increased precision and confidence. Furthermore, the use of miniplate fixation decreased the period of maxillomandibular fixation. However, a larger series is required to evaluate the utility of this system more thoroughly. [ABSTRACT FROM AUTHOR]