Facial soft tissue characteristics of patients with different types of malocclusion.

BACKGROUND: This study aimed to investigate the facial soft tissue characteristics of patients with different types of malocclusion. METHODS: The 3dMD scanning data of patients with malocclusion admitted to our hospital from January 2018 to April 2022 were analyzed retrospectively. Forty-seven patients with Class I malocclusion, 43 patients with Class II malocclusion and 44 patients with Class III malocclusion were selected. All patients underwent 3dMD scans prior to orthodontic treatment. Then the differences in the 3D morphological parameters of the facial soft tissues were compared between different sexes and different types of malocclusion. Spearman's correlation was further used to analyze the correlation between each parameter and the classification of malocclusion. RESULTS: In the Class I group and Class II group, there were no significant differences in the 3D morphometric parameters of malocclusion patients of different sexes (P > 0.05). There were significant differences between Al (R)-AL (L), Ac (R)-Ac (L), Prn-Ac (L), n-Prn-Sn, and Al (R)-Al (L)/Ac (L)-Ah (L) values among the three groups of patients. Spearman correlation analysis showed that Ac (R)-Ac (L) and Al (R)-Al (L)/Ac (R)-Ac (L) were correlated with the type of malocclusion. CONCLUSION: Differences in facial soft tissues exist in patients with Class I, II, and III malocclusion. 3dMD technique may be helpful in developing an effective treatment plan prior to orthodontic treatment.

Mouth Breathing Habit and Their Effects on Dentofacial Growth in Children in the Age Range of 6-14 Years: A Cephalometric Study.

Nasal breathing protects the upper airway and is responsible for adequate craniofacial development. It is believed that long-standing obstruction causes mouth breathing, which has a negative impact on the craniofacial complex. Aim: The study aimed to verify the effects of mouth breathing on the dentofacial structure by employing cephalometric analysis. Materials and methods: The present study was conducted on 68 patients (34 mouth-breathing group or study group and 34 nasal-breathing group or control group) aged 6-14 years. Study subjects were screened based on the inclusion and exclusion criteria. Clinical assessment of nasal function was done to select the mouth breathing patients and referred for ear, nose, and throat (ENT) clearance. Lateral cephalograms were taken for the study subjects, including both nasal and mouth breathers, over which selected landmarks were marked to evaluate linear, skeletal, and dental angular variables for comparison with cephalometric variables of a normal child. Results: The mean values of facial height (N-Me, ANS-Me) and mandibular plane angle (SN-GoGn) were significantly higher for mouth breathers. The gonial angle (Ar-GoMe) for ages 6-14 years was significantly lower in the nasal breathing group. Conclusion: The study led to the conclusion that all subjects with a history of mouth breathing showed an increase in facial height, gonial angle, and mandibular plane angle. Clinical significance: Evaluating dentoskeletal changes in a patient with a mouth-breathing habit helps discern the importance of early identification and interception at an early age, thereby ensuring a functional environment adequate for physiological growth and dentofacial esthetics. How to cite this article: Chowdhary K, Yadav G, Rai A, et al. Mouth Breathing Habit and Their Effects on Dentofacial Growth in Children in the Age Range of 6-14 Years: A Cephalometric Study. Int J Clin Pediatr Dent 2024;17(5):545-551.

Is bracket bonding with guided bonding devices accurate enough for crowded dentition?

BACKGROUND: This research aimed to study whether bracket bonding using guided bonding devices (GBDs) is accurate enough for crowded dentitions in vitro. METHODS: Fifteen three-dimensionally (3D) printed resin model sets were included and divided into three groups: mild, moderate, and severe crowding. The resin models were scanned and virtually bonded with brackets. Corresponding GBDs were generated and 3D printed. Subsequently, the brackets were bonded to the resin models on a dental mannequin using the GBDs. The models with bonded brackets were scanned, and comparisons were made between the positions of the actually bonded and the planned ones to evaluate possible deviations. RESULTS: There was no immediate bonding failure in any group. The bonding duration tended to increase with crowding severity (P > 0.05). Almost all linear and angular deviations in all groups were below 0.5 mm and 2°, respectively, and no statistically significant difference was found among the different crowding degrees (P > 0.05). In all groups, the brackets tended to deviate lingually and had buccal crown torque. Brackets in the groups with mild and severe crowding showed a tendency for mesiobuccal rotation. CONCLUSION: GBDs provide high bracket bonding accuracy for dentitions with different crowding degrees and, thus, could hopefully be applied to uncrowded and crowded dentitions alike.

Current Trends in Pediatric Orthodontics: A Comprehensive Review.

Pediatric orthodontics is a critical field focusing on the diagnosis, prevention, and treatment of dental and facial irregularities in children. This comprehensive review explores current trends and methodologies in pediatric orthodontics and discusses the multifactorial etiology of malocclusions, including genetic, environmental, and disease-related factors. The importance of proper diagnosis is highlighted, and the extraoral, intraoral, and functional evaluations essential for effective treatment planning are detailed. Various orthodontic conditions such as Class III and Class II malocclusions, abnormal oral habits, arch length discrepancies, anterior and posterior crossbites, open bites, and deep bites are examined in depth. The review also addresses the role of temporomandibular joint disorders (TMDs) and obstructive sleep apnea (OSA) in pediatric patients, emphasizing the need for early and accurate diagnosis to facilitate appropriate intervention. The use of clear aligners in early orthodontic intervention is evaluated given their efficacy and improved patient satisfaction compared to traditional appliances. Additionally, the article discusses the non-advisability of early interception for certain self-correcting malocclusions and the limitations of pediatric orthodontic treatment, including compliance-related issues and the unique anatomical considerations of deciduous dentition. This review aims to provide a detailed understanding of contemporary practices and challenges in pediatric orthodontics, offering insights for clinicians to enhance treatment outcomes and patient care.

Honoring Professor Hugo Lorenz Obwegeser: A Visionary in Maxillofacial Surgery and Orthodontics.

Hugo Lorenz Obwegeser was a pioneering Austrian surgeon whose contributions profoundly transformed the field of maxillofacial surgery. His groundbreaking work marked a pivotal turning point, enabling more sophisticated and effective corrections of facial deformities. Obwegeser revolutionized his area of expertise by introducing innovative osteotomies of the mandible and maxilla, which became foundational techniques for addressing facial asymmetries. In addition to his surgical advancements, Obwegeser was a key figure in establishing the European Association for Cranio-Maxillo-Facial Surgery, helping to define the modern scope of the specialty. His legacy in maxillofacial surgery is distinguished by his unwavering commitment to innovation, mentorship, and the continuous advancement of surgical practices. This article aims to honor the extraordinary achievements of Hugo Lorenz Obwegeser and his lasting impact on the field of maxillofacial surgery.

DetSegDiff: A joint periodontal landmark detection and segmentation in intraoral ultrasound using edge-enhanced diffusion-based network.

Individuals with malocclusion require an orthodontic diagnosis and treatment plan based on the severity of their condition. Assessing and monitoring changes in periodontal structures before, during, and after orthodontic procedures is crucial, and intraoral ultrasound (US) imaging has been shown a promising diagnostic tool in imaging periodontium. However, accurately delineating and analyzing periodontal structures in US videos is a challenging task for clinicians, as it is time-consuming and subject to interpretation errors. This paper introduces DetSegDiff, an edge-enhanced diffusion-based network developed to simultaneously detect the cementoenamel junction (CEJ) and segment alveolar bone structure in intraoral US videos. An edge feature encoder is designed to enhance edge and texture information for precise delineation of periodontal structures. Additionally, we employed the spatial squeeze-attention module (SSAM) to extract more representative features to perform both detection and segmentation tasks at global and local levels. This study used 169 videos from 17 orthodontic patients for training purposes and was subsequently tested on 41 videos from 4 additional patients. The proposed method achieved a mean distance difference of 0.17 ± 0.19 mm for the CEJ and an average Dice score of 90.1% for alveolar bone structure. As there is a lack of multi-task benchmark networks, thorough experiments were undertaken to assess and benchmark the proposed method against state-of-the-art (SOTA) detection and segmentation individual networks. The experimental results demonstrated that DetSegDiff outperformed SOTA approaches, confirming the feasibility of using automated diagnostic systems for orthodontists.

Prevalence and nature of bullying in schoolchildren aged 10-14 years and its association with malocclusion: A cross-sectional study in the South East of the UK.

OBJECTIVE: To investigate the prevalence of, and relationship between, bullying and malocclusion in schoolchildren aged 10-14 years in the South East of the UK. DESIGN: Cross-sectional cohort study. SETTING: Sixteen primary and secondary schools in South East of the UK. PARTICIPANTS: Schoolchildren aged 10-14 years who were consented to participate. METHODS: The prevalence and nature of bullying were measured using a questionnaire. Traits of malocclusion and the need for orthodontic treatment were assessed by clinical examination and determined by the Index of Orthodontic Treatment Need (IOTN) Dental Health (DHC) and Aesthetic components (AC). RESULTS: Complete data were collected for 698 participants. The number defined as being bullied was 68 (9.7%). There was no difference in the prevalence of bullying between gender, ethnicity or age. Higher rates of bullying were reported in mixed sex schools (P = 0.03). Participants with an increased overjet (P = 0.02) and/or a greater need for treatment, as measured by IOTN DHC (P = 0.01) and AC (P = 0.01), reported higher rates of bullying. While there was no difference in the overall prevalence of bullying between genders, boys were more likely than girls to experience physical bullying (P <0.001) and being called names (P = 0.03). CONCLUSION: A significant relationship was evident between being bullied and certain traits of malocclusion.

Simultaneous labial and lingual augmented corticotomy assisted presurgical orthodontics in class III patients: the morphological aspects of the mandibular anterior ridge with cone-beam computed tomography.

OBJECTIVES: This study aims to investigate the changes in alveolar bone following the simultaneous performance of labial and lingual augmented corticotomy (LLAC) in patients with insufficient alveolar bone thickness on both the labial and lingual sides of the mandibular anterior teeth during presurgical orthodontic treatment. MATERIALS AND METHODS: Thirth-five surgical patients with skeletal Class III malocclusion were included: 19 (LLAC group) accepted LLAC surgery during presurgical orthodontic treatment, and 16 (non-surgery group, NS) accepted traditional presurgical orthodontic treatment. Cone-beam computed tomography (CBCT) scans were obtained before treatment (T0) and at the completion of presurgical orthodontic treatment (T1). The amount of vertical alveolar bone and contour area of the alveolar bone in the labial and lingual sides of mandibular incisors were measured. RESULTS: After presurgical orthodontic treatment, the contour area of the alveolar bone at each level on the lingual side and alveolar bone level on both sides decreased significantly in the NS group (P < 0.001). However, the labial and lingual bone contour area at each level and bone level increased significantly in the LLAC group (P < 0.001). The bone formation rate in the lingual apical region was the highest, significantly different from other sites (P < 0.001). CONCLUSIONS: During presurgical orthodontic treatment, LLAC can significantly increase the contour area of the labio-lingual alveolar bone in the mandibular anterior teeth to facilitate safe and effective orthodontic decompensation in skeletal Class III patients. CLINICAL RELEVANCE: This surgery has positive clinical significance in patients lacking bone thickness (< 0.5 mm) in the labial and lingual sides of the lower incisors.

Incidence of enamel defects on permanent canine teeth following extraction of linguoverted mandibular deciduous canine teeth in dogs.

Interceptive orthodontics may be indicated in puppies exhibiting dental malocclusion with linguoverted deciduous mandibular canine teeth to alleviate pain and prevent teeth interlock, which may affect growth and development of the mandibles. Historically extraction of deciduous mandibular canine teeth has been recommended as soon as a malocclusion is identified, often as early as 6-8 weeks of age and no later than 12 weeks of age. This early surgical intervention of deciduous teeth extractions risks potential damage to the developing permanent canine teeth resulting in enamel defects often referred to as a Turner's tooth or Turner's hypoplasia. A search of medical records from five veterinary specialty dentistry practices was conducted to identify dogs 8-12 weeks of age who (a) underwent deciduous mandibular canine extractions for management of class 1 or class 2 malocclusion with linguoverted mandibular canine teeth, and (b) were seen for at least one recheck exam to assess for enamel defects on permanent mandibular canine teeth. Furthermore, data was collected to determine the number of dogs that required additional treatment after eruption of the permanent canine teeth due to linguoversion of the permanent canine teeth. All procedures were performed by a board-certified veterinary dentist™ or a supervised veterinary dentistry resident. Seventy-four dogs fit the inclusion criteria and had a total of 143 deciduous mandibular canine teeth extracted, out of which 13 dogs exhibited enamel defects affecting 21 permanent canine teeth. The 13 affected dogs represent a 17.5% cumulative incident rate 13/74 (95%CI 11-28%). Of all extracted teeth, 14.6% (21/143) had enamel defects affecting permanent canine teeth. Twenty-eight dogs required additional treatment to prevent the permanent mandibular canine teeth from causing trauma to the hard palate and gingiva which represented 37.8% (28/74) of all dogs in the study. Age and sex of the dog at the time of extraction were not found to be associated with the likelihood of incidence of enamel defects. This is the first reported rate of enamel defects on permanent mandibular canine teeth following extraction of deciduous mandibular canine teeth and is important to consider when advising or performing extraction of deciduous teeth in dogs.

Early Intervention in Class II Division 1 Malocclusion Using an Activator Appliance: A Case Study.

The field of orthodontics has traditionally been regarded as the primary specialty within dentistry. As per Dr. Tweed's recommendation, historical treatment approaches often entailed the extraction of four premolar teeth. Nonetheless, early orthodontic intervention can frequently obviate the necessity for extractions, thus preserving the integrity, functionality, and aesthetic appeal of the dentition. This case report details a non-extraction approach for managing a developing skeletal Class II malocclusion, characterized by a skeletal disharmony between the maxilla and mandible. The chosen treatment option is influenced by factors such as the patient's age, growth potential, the severity of the malocclusion, and the patient's adherence to the prescribed treatment regimen. Myofunctional appliances have been identified as effective in addressing Class II Division 1 malocclusion resulting from mandibular retrusion.

Surgical and Camouflage Orthodontic Treatment of Anterior Open Bite: Comparison of Profile Attractiveness.

OBJECTIVE: To evaluate the profile's attractiveness between the different protocols for treating the anterior open bite. METHODS: The sample comprised 39 patients with anterior open bite treated with or without extractions, divided into two groups: The surgical group (G1) comprised 21 subjects (10 males, 11 females) with a mean initial age of 21.86 years (SD = 5.09), treated with fixed orthodontic appliance followed by orthognathic surgery, for a total mean period of 2.53 years (SD = 0.61). The mean overbite was -5.01 mm (SD = 2.50); The camouflaged group (G2) comprised 18 subjects (9 males, 9 females), with a mean initial age of 20.47 years (SD = 4.19), treated only with fixed orthodontic appliance, for a total mean period of 2.56 years (SD = 0.94). The mean overbite was -4.28 mm (SD = 1.15). Lateral photographs from pretreatment and posttreatment were used. These photographs were evaluated by 46 laypeople and 67 dentists, who rated the attractiveness of each profile from 0 (most unattractive profile) to 10 (most attractive profile). Intergroup comparisons were performed with independent t-tests. RESULTS: Both groups presented improvement in the profile attractiveness with treatment (p < 0.001). Before treatment, the profile of the surgical group was significantly less attractive than the profile of the camouflaged group (p < 0.001). The surgical presented a more attractive profile at the final stage than the camouflaged group (p < 0.001). The surgical group showed a greater improvement in profile attractiveness with treatment than the camouflaged group (p < 0.001). CONCLUSION: In the final stage, the surgical presented a more attractive and greater improvement in profile attractiveness than the camouflaged group. The laypeople and dentists judged similarly the initial profile attractiveness.

Evaluation of the Effects of Orthopedic Treatment on the Dentofacial Structure and Upper Airway of Subjects with Skeletal Class III Malocclusion.

Objective: The present study aimed to evaluate the effect of rapid maxillary expansion (RME) and face mask treatment on the upper airway in patients with maxillary retrusion in two dimensions using digital cephalograms and volumetric evaluation using acoustic rhinometric measurements. Methods: A total of 22 individuals with a concave profile and skeletal and dental Class III malocclusion during growth and development with a mean age of 9.9±1.38 years were included in the study. A bonded RME appliance and a petit face mask were adapted for the patients. Before treatment (T0) and after maxillary protraction (T1), lateral cephalometric films and acoustic rhinometric recordings were obtained. The dependent sample t-test was used for statistical evaluation. Results: Cephalometric analysis revealed forward movement of the maxilla and backward downward rotation of the mandible. A significant increase was observed in the nasopharyngeal and oropharyngeal regions of the upper airway. Three-dimensional evaluation of the upper airway by acoustic rhinometry revealed only an increase in the volumes of the left nasal cavity after decongestant administration. A statistically significant increase in acoustic rhinometric measurements in nasal valves. When the correlation of the cephalometric findings of the nasopharyngeal region with the acoustic rhinometry findings was examined, no statistically significant relationship was found. Conclusion: As a result of this study, we observed an increase in the cephalometric measurements of the nasopharyngeal and oropharyngeal areas. A significant increase was observed in the minimal cross-sectional area measured by acoustic rhinometry.

Pharyngeal Airway Space Changes after Single Mandibular and Two-Jaw Surgery in Patients with Skeletal Class II Malocclusion.

Objective: To retrospectively evaluate the effects of single mandibular advancement (MA) and two-jaw surgery (2J-S) on the pharyngeal airway space (PAS) and hyoid position for the correction of skeletal Class II malocclusion. Methods: Eleven adult patients who underwent only MA surgery and twelve adult patients who underwent Le Fort I maxillary impaction-MA surgery (2-JS) were included in the retrospective study. A total of 46 cephalometric recordings obtained before (T1) and after treatment (T2) were examined. Craniofacial changes, area, and linear measurements of the pharyngeal airway and hyoid bone position were obtained in both groups. The Wilcoxon signed-rank test was used to evaluate time-dependent changes within groups. The Mann-Whitney U test was used to compare differences between groups. Results: Hyoid-Vert values increased significantly in both groups (MA, p<0.01; 2J-S, p<0.05); however, Hyoid-Hor values decreased significantly only in the 2J-S group (p<0.01). The anteroposterior dimensions of the airway increased in both groups, except for the PNS-P and PPS groups (p<0.01). Although a significant increase was observed in the nasopharyngeal area (A1) in the MA group (p<0.05), the decrease was found to be statistically significant in 2JG (p<0.01). Significant increases were found in the oropharyngeal (A2) and hypopharyngeal areas (A3) in both groups (p<0.01, p<0.05). Conclusion: Both surgical procedures for the correction of Class II malocclusion resulted in increased hypopharyngeal, oropharyngeal, and total airway measurements.

Evaluation of Incisor Position in a Sample of Orthodontic Patients.

BACKGROUND: To achieve a successful result, the orthodontist must use a systematic approach to plan the orthodontic treatment. Defining the correct position of the upper and lower incisors and evaluating their relationship with intermaxillary discrepancy and facial divergence have been recognized as the starting point for the diagnostic decision regarding extractions and anchorage requirements. The aim of our study was to analyze the relationship between intermaxillary discrepancy (ANPg^), mandibular inclination (SN^GoGn), lip incompetence, and the positioning of the upper and lower incisors (UIPs and LIPs) in a group of orthodontic patients. This retrospective study included 290 lateral cephalograms in 122 males (42.1%) and 168 females (57.9%) aged 8 to 53 years (median 14; interquartile range IQR 12-17). Data were analyzed by means of one-way Analysis of Variance (ANOVA) and linear regression analysis. RESULTS: This study showed a statistically significant increase in LIP values in patients with lip incompetence (p < 0.001). Moreover, the distribution of LIPs in groups with various SN^GoGn and ANPg^ angles was significantly different (p < 0.001). The regression analysis also showed a positive association between the LIP and SN^GoGn and between the LIP and ANPg^. CONCLUSION: The LIP presented a statistically significant difference in patients with and without lip incompetence, which varied significantly in subjects with different sagittal malocclusions and vertical face patterns.

A Prospective Randomized Control Trial of Lingual Frenuloplasty with Myofunctional Therapy in Patients with Maxillofacial Deformity in a Polish Cohort.

Introduction: There are few publications concerning ankyloglossia in mixed-aged groups utilizing myofunctional therapy and frenuloplasty in patients undergoing orthodontic treatment and maxillofacial surgery. While it is well known that ankyloglossia is mainly diagnosed in babies, research on functional and structural disorders in different age groups is less common. Thus, there is a high need for specific information about the influence and effectiveness of frenuloplasty with myofunctional therapy on the stomatognathic function and final treatment outcome for a wider variety of patients, especially those with maxillofacial deformities. Aim: This paper aims to evaluate the impact of lingual frenuloplasty as an adjunct to myofunctional therapy for the treatment of ankyloglossia in children and adults with maxillofacial deformity. Methods: Prospective randomized control trial with 155 subjects. Methods were based on visual observation and examination of the oral cavity. There were two groups: myofunctional therapy vs. myofunctional therapy and lingual frenuloplasty. Patients were randomized based on order of entry into the study. χ2 test, Kruskal-Wallis, ANOVA, Student's t-test and others were used for statistical analyses. Results: The presented protocol with myofunctional therapy and surgical procedures proved to be significantly more effective in improving tongue mobility and stomatognathic functions such as swallowing, breathing, and oral resting postures as compared to the reference group who underwent myofunctional therapy only. Conclusions: Lingual frenuloplasty with myofunctional therapy is highly effective in restoring the equilibrium of the orofacial muscles and the skeleton, which is often disturbed and may lead to unstable functional effects among patients considering orthodontic and orthognathic treatments for maxillofacial deformities.

Nonsurgical class III correction in adolescence using modified fixed reverse twin-block therapy and fixed appliances - a case series.

Skeletal class III malocclusion is a therapeutic challenge in orthodontic practice. Reverse functional appliances such as reverse twin block (RTB) are used to correct class III skeletal and occlusal disharmonies associated with functional anterior shift in growing patients. However, treatment options become limited with increasing age, especially when patients desire nonsurgical and nonextraction camouflage treatment. This report illustrates the successful nonsurgical treatment of class III malocclusion during adolescence and adulthood, exacerbated by a functional anterior shift that resulted in overclosure of the mandible. A modified fixed RTB was utilized to posture the mandible backwards, thereby inducing active clockwise rotation of the mandible. After treatment, patients demonstrated significantly improved maxillomandibular relationships, well-maintained stable occlusion, and facial esthetics. Satisfactory occlusal, esthetic, and functional outcomes achieved in the present cases underline the fact that dentoalveolar changes induced by fixed RTB can be utilized even past a patient's peak pubertal growth period to obtain changes that aid in correcting a class III malocclusion. A synergistic combination of modified fixed RTB therapy accompanied by comprehensive fixed mechanotherapy is a viable treatment alternative for the correction of aptly selected mild to moderate skeletal class III malocclusions associated with functional anterior shift, anterior crossbites, and mandibular overclosure.

Prediction on the chin advancement of the twin block functional appliance in growing Chinese patients using the cephalometric markers: a retrospective study.

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 (ß = -0.26, 95% CI: -0.06 to -0.01, p = 0.01) and without (ß = -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.

Familial severe skeletal Class II malocclusion with gingival hyperplasia caused by a complex structural rearrangement at the KCNJ2-KCNJ16 locus.

The aim of this work was to identify the underlying genetic cause in a four-generation family segregating an unusual phenotype comprising a severe form of skeletal Class II malocclusion with gingival hyperplasia. SNP array identified a copy number gain on chromosome 1 (chr1); however, this chromosomal region did not segregate correctly in the extended family. Exome sequencing also failed to identify a candidate causative variant but highlighted co-segregating genetic markers on chr17 and chr19. Short- and long-read genome sequencing allowed us to pinpoint and characterize at nucleotide-level resolution a chromothripsis-like complex rearrangement (CR) inserted into the chr17 co-segregating region at the KCNJ2-SOX9 locus. The CR involved the gain of five different regions from chr1 that are shuffled, chained, and inserted as a single block (∼828 kb) at chr17q24.3. The inserted sequences contain craniofacial enhancers that are predicted to interact with KCNJ2/KCNJ16 through neo-topologically associating domain (TAD) formation to induce ectopic activation. Our findings suggest that the CR inserted at chr17q24.3 is the cause of the severe skeletal Class II malocclusion with gingival hyperplasia in this family and expands the panoply of phenotypes linked to variation at the KCNJ2-SOX9 locus. In addition, we highlight a previously overlooked potential role for misregulation of the KCNJ2/KCNJ16 genes in the pathomechanism of gingival hyperplasia associated with deletions and other rearrangements of the 17q24.2-q24.3 region (MIM 135400).

Assessing the Efficacy of Early versus Late Orthodontic Intervention in the Management of Class II Malocclusion: A Comparative Analysis.

Background: Class II malocclusion is a common orthodontic issue characterized by the excessive protrusion of the upper teeth relative to the lower teeth. Early intervention during mixed dentition has been advocated to guide skeletal growth and potentially reduce the severity of malocclusion. Materials and Methods: A comparative analysis was conducted to evaluate the efficacy of early (before the pubertal growth spurt) versus late (after the pubertal growth spurt) orthodontic intervention in managing Class II malocclusion. A cohort of 100 patients diagnosed with Class II malocclusion was divided into two groups: early intervention group (n = 50) and late intervention group (n = 50). Treatment outcomes including changes in overjet, molar relationship, and cephalometric measurements were assessed before and after orthodontic treatment. Results: In the early intervention group, the mean reduction in overjet was 5.2 mm (SD = 1.3), while in the late intervention group, it was 3.8 mm (SD = 1.6). The improvement in molar relationship was greater in the early intervention group (mean change = 4.5 mm, SD = 1.1) compared to the late intervention group (mean change = 3.1 mm, SD = 1.4). Cephalometric analysis revealed significant differences in skeletal and dental parameters between the two groups, with greater improvements observed in the early intervention group. Conclusion: Early orthodontic intervention shows superior efficacy in managing Class II malocclusion compared to late intervention. Early treatment leads to greater reductions in overjet, improvements in molar relationship, and favorable changes in skeletal and dental parameters. These findings underscore the importance of timely orthodontic intervention, particularly during the mixed dentition stage, for optimal management of Class II malocclusion.

Assessing the Co-relation between Mandibular Flare and Thickness of Lingual Cortex in Relation to the Third Molars: A Retrospective Cross-sectional Study.

Aim: To assess the co-relation between mandibular flare and thickness of lingual cortex in relation to the third molars. Materials and Methods: Retrospectively obtained computed tomography (CT) data of 26 patients was used after classifying them into respective skeletal malocclusion groups (classes I, II, and III). Thickness of lingual cortex was measured at crestal, middle, and apical levels in mandibular third molar region. Two angular and two linear measurements were used to measure mandibular flare. Angular measurements included the angle between condylion (Co) and menton (Me), and between gonion (Go) and menton (Me). Linear measurements included bigonial and bicondylion widths. Results: The two angular measurements did not differ significantly among the three skeletal malocclusion groups. Contrastingly, bicondylion width differed significantly among the three groups. Class II group showed no significant correlation between mandibular flare and lingual cortical thickness. Class III group demonstrated a significant negative correlation of linear and angular measurements with cortical bone thickness. Bicondylion width was significantly more in Class III group than in other skeletal groups, which proved an increased mandibular flare in patients with Class III malocclusion. Conclusion: Increase in mandibular flare was associated with decreased thickness of lingual cortical bone.