Treatment Of Skeletal Class Research Articles

Three-dimensional changes in the soft tissue chin after mandibular setback surgery in adult Japanese patients with skeletal class III malocclusion

ABSTRACT Purpose The purpose of the present study is to improve the quality of prediction of soft tissue morphology by clarifying the relationship between the amount of three-dimensional (3-D) changes of hard tissue and the morphological differences of the soft tissue chin before and after orthognathic surgery in skeletal class III malocclusion. Materials and methods Preoperative and six-month postoperative CT was used to analyze the changes in 26 adult Japanese skeletal class III patients. The mean age was 25.5 years. Lateral cephalograms were analyzed to evaluate the initial antero-posterior jaw relationship and the changes before and after treatment. Three-D masks and bone structures were reconstructed using 3-D modelling software, and the final chin models were defined for further analysis following voxel-based registration. Correlation and linear regression analyses were performed to clarify the relationship between the movement of the soft tissue chin and the underlying bone. Results The soft tissue chin volume and surface area significantly increased after surgery. The thickness of the chin significantly increased only at pogonion and menton after surgery. Furthermore, a statistically significant correlation between the movement of soft tissue chin and underlying bone was found. Consequently, the regression model predicted the changes in soft tissue chin from the movement of the underlying bone. Conclusion Three-D analysis of the soft tissue chin revealed a significant change in response to surgical orthodontic treatment in skeletal class III adult patients, and soft tissue chin movement could be predicted by using 3-D CT data when planning orthognathic treatment.

A nomogram prediction of gingival recession in mandibular incisors of orthodontic-orthognathic treated skeletal class III malocclusion with or without PAOO: A retrospective cohort study

BackgroundTo assess the alterations in gingival thickness and the occurrence gingival recession subsequent to orthodontic-orthognathic treatment of mandibular incisors in skeletal Class III and identify risk factors associated with gingival recession. MethodsIn this retrospective cohort study, we enrolled 33 patients exhibiting skeletal Class III malocclusion, totaling 131 mandibular incisors, who were undergoing orthodontic- orthognathic treatment that did not involve extraction of mandibular teeth. The subjects were categorized into surgery group (S; n = 17; ANB = −5.55 ± 3.26; IOFTN = 4.60 ± 0.51, scores ranging: 4.3–5.3) and non-surgery group (NS; n = 16; ANB = −3.00 ± 4.08; IOFTN = 4.63 ± 0.50, scores ranging: 4.3–5.4), based on if they had history of Periodontally Accelerated Osteogenic Orthodontics surgery (S) or not (NS). Patients in S group received orthognathic surgery about 1–1.5 years after Periodontally Accelerated Osteogenic Orthodontics surgery. Alterations in gingival thickness, gingival recession, and keratinized gingival width were compared before and after orthodontic-orthognathic treatment. Logistic regression analysis was used to construct a gingival recession prediction model and draw nomograms. ResultsAfter orthodontic-orthognathic treatment, the gingival thickness and keratinized gingival width in NS group decreased by 0.15 ± 0.21 mm and 0.74 ± 0.91 mm, whereas those in the S group increased by 0.32 ± 0.28 mm and 2.09 ± 1.51 mm (P < 0.05). After orthodontic-orthognathic, the percentage of gingival recession increased by 47.62 % in NS group, which was 14.77 times that of S group (P < 0.05). Multivariate regression analysis indicated that skeletal Class III patients with a gingival thickness below 0.72 mm, an alveolar bone height exceeding 2.36 mm, and an alveolar bone thickness under 0.45 mm might be at elevated risk for developing gingival recession following orthodontic - orthognathic therapy. ConclusionsDrawing on the findings of our investigation, we concluded the risk of gingival recession of mandibular anterior teeth increased after orthodontic-orthognathic treatment in skeletal Class III, whereas Periodontally Accelerated Osteogenic Orthodontics surgery could significantly improve the periodontal phenotype and prevent gingival recession.

Fixed vs Removable Twin-block Treatment in Skeletal Class II Malocclusion

Fixed vs Removable Twin-block Treatment in Skeletal Class II Malocclusion

Study on the effect of chin morphology on orthodontic treatment.

To investigate the effect of different soft-tissue morphologies on the treatment of skeletal class Ⅰ malocclusion patients by analyzing measurement data before and after treatment. Pre- and post-treatment lateral cephalograms of 55 adult female Angle class Ⅰ patients were collected in the Department of Orthodontics, Hospital of Stomatology, Jilin University from January 2012 to December 2020. Chin soft-tissue morphologies in the lateral cranial radiographs were used to divide the patients into an abnormal chin morphology group (flat and retracted chins, n=27) and a normal chin morphology group (rounded and prominent chins, n=28). Relevant soft- and hard-tissue indexes were selected to study in-group varieties and intergroup differences in the varying chin morphologies before and after treatment. The chin-lip angle, mandibular chin angle, mandibular chin vertex angle, PP-MP, LL-E, UL-E, Po-Pos, and B-B' thickness in the abnormal chin morphology group were significantly higher than those in the normal chin morphology group (P<0.05). Furthermore, m∶BMe and n∶B'Mes in the abnormal chin morphology group were signi-ficantly lower than those in the normal chin morphology group (P<0.05). After treatment, the mandibular chin angle, mandibular chin vertex angle, U1-SN, L1-MP, LL-E, UL-E, SNA, SNB, and B-B' thickness of the abnormal chin morphology group significantly decreased (P<0.05), whereas the nasolabial angle, m∶BMe, n∶B' Mes, and Po-Pos significantly increased (P<0.05). In the normal chin morphology group, the U1-SN, L1-MP, LL-E, UL-E, and B-B' thicknesses decreased significantly (P<0.05), whereas the nasolabial angle significantly increased (P<0.05). Among them, m∶BMe and n∶B' Mes were positively correlated. Chin morphology affects the formulation of treatment plans. Compared with the normal chin morphology group, the abnormal chin morphology group required a larger retraction of incisors. Although the chin of soft-tissue morphology is related to the morphology of bones, the changes in soft tissue chin after treatment cannot be directly predicted according to the bone changes. Soft-tissue chin morphology affects the aesthetic assessment of the soft-tissue lateral profile and the change in soft tissue before and after treatment. The method of predicting the change in soft-tissue chin after treatment should consider the morphology of the soft-tissue chin.

Three-dimensional evaluation of PowerScope appliance assisted with low-level laser therapy on mandibular changes in the treatment of skeletal class 2 malocclusions: A prospective clinical study.

Three-dimensional evaluation of PowerScope appliance assisted with low-level laser therapy on mandibular changes in the treatment of skeletal class 2 malocclusions: A prospective clinical study.

Pharyngeal airway volume changes following treatment of skeletal class II patients using a miniplate-supported buccally acting distalizer: A retrospective 3-dimensional CBCT study

Pharyngeal airway volume changes following treatment of skeletal class II patients using a miniplate-supported buccally acting distalizer: A retrospective 3-dimensional CBCT study

Camouflage Treatment of Skeletal Class III Patient with Anterior Crossbite, Spaced Dentition and Missing Mandibular Left First Molar

Camouflage Treatment of Skeletal Class III Patient with Anterior Crossbite, Spaced Dentition and Missing Mandibular Left First Molar

Three-dimensional evaluation of the efficacy of Powerscope appliance in treatment of skeletal Class 2 malocclusion: A prospective clinical study

Three-dimensional evaluation of the efficacy of Powerscope appliance in treatment of skeletal Class 2 malocclusion: A prospective clinical study

Evaluation of the Functional Treatment of Patients With Skeletal Class II Malocclusion Using Low-Level Laser Therapy-Assisted Twin-Block Appliance: A Three-Arm Randomized Controlled Trial.

BackgroundDifferent techniques have been used to reduce functional treatment time including low-level laser therapy (LLLT), and the majority of studies have been conducted on animals. Therefore, the aim of the current study was to evaluate the effects of LLLT on improving orthodontic functional treatment using the Twin-Block (TB) appliance.Materials and methodsThis study was a three-arm, parallel-group randomized controlled trial. Patients were selected using the following inclusion criteria: skeletal Class II Division 1 malocclusion resulting from mandibular retrognathia (angle between the anterior cranial base and the NB plane (i.e., SNB angle): 73°-78°), the sagittal skeletal discrepancy angle (ANB angle) between 4° and 9°, and overjet between 5 and 9 mm. Forty-eight patients were randomly allocated into three equal groups. In the LLLT-TB group, the low-level laser device was used with a wavelength of 808 nm and power of 250 mW in addition to functional treatment with a Twin-Block appliance. The laser was applied on the skin at the bilateral temporomandibular joint (TMJ) regions, at five points, each point received 5 J of the laser for 20 seconds. The laser course was twice a week in the first month, every two weeks in the second month, and every three weeks up to the end of the treatment. The second group (the TB group) received functional treatment with a Twin-Block appliance, while patients in the third group (the untreated control group (UCG)) were observed for nine months without any intervention.ResultsThere were statistically significant differences in treatment periods between the LLLT-TB group and the TB group (129 days and 235 days, respectively, P-value<0.001). The change in the effective mandibular length (Co-Gn) was the highest in the LLLT-TB group compared with the TB and the UCG groups (4.41 mm, 3.66 mm, and 1.07 mm, respectively; P-value<0.001).ConclusionsThe application of low-level laser therapy on the condylar regions accelerated the functional treatment in skeletal Class II malocclusion patients by approximately 45% and increased the bone growth and mandibular length. The improvement in the SNB angle was similar in both interventional groups. Irradiation of low-level laser stimulated bone growth at the condyles and did not cause anterior movement of the temporomandibular joint following functional orthopedic correction.

Late upper airway constriction and its prevention by interceptive functional appliance therapy- A review

Introduction: Sleep-disordered breathing (SDB) is one of the poorly diagnosed disorders which affects the quality of life of patients. The SDB is a spectrum of problems ranging from simple snoring to obstructive sleep apnoea (OSA) which involves complete collapse of the pharyngeal airway passage during sleep resulting in airflow cessation and consequent arousals. A noteworthy etiological factor of OSA is mandibular retrognathism. Imaging studies on craniofacial structures in OSA patients have shown decreased oropharyngeal and hypopharyngeal depth, elongated soft palate, altered tongue posture, and increased hyoid bone-to-mandible distance. The management modalities of OSA are positive airway pressure (PAP) and oral appliance therapy. The modus operandi of mandibular advancement devices (MADs) is the same as of myofunctional therapy instituted by orthodontists for the treatment of skeletal Class II malocclusions with mandibular retrusion in growing patients. By virtue of the increase in the mandibular length and advancement in mandibular position, pharyngeal airway space is enlarged along with favorable changes in the soft palate, tongue posture, and hyoid bone position. The focus of the present review is to consolidate the available literature on the long-term effects of functional appliance treatment. It is hypothesized that interceptive functional appliance therapy in the growing stage could be a viable strategy for the prevention of OSA development during adulthood. The review also highlights the importance of the need for more studies emphasizing the long-term impact of functional treatment to establish the role of the same in reducing the OSA treatment burden during adulthood.

Surgical Orthodontic Treatment for Skeletal Class I with Facial Asymmetry and Occlusal Cant: A Case Report

Background: Cases of facial asymmetry with chin deviation and canted occlusal plane represent a challenge in orthodontic treatment. Case Report: We report successful surgical orthodontic treatment for skeletal Class I with severe facial asymmetry. Miniscrew anchorage was used to decompensate the canted occlusal plane in presurgical orthodontic treatment with a fixed appliance by the intrusion of the maxillary right molars and extrusion of the left molars. Then, orthognathic surgery consisting of bilateral sagittal split osteotomy for asymmetric mandibular setback was performed. Treatment resulted in marked improvement of facial asymmetry. Conclusion: The use of miniscrew implant anchorage may represent a superior presurgical orthodontic treatment and expand the possibility of treatment by one-jaw surgery.

Comparative efficacy of the bone‐anchored maxillary protraction protocols for orthopaedic treatment in skeletal Class III malocclusion: A Bayesian network meta‐analysis

To compare the treatment effects of five bone-anchored maxillary protraction protocols (BAC3E, BAMP, BARME-FM, BARME-ME, SAFM) for skeletal Class III malocclusion. We conducted a systematic literature search through CENTRAL, EBSCO, PubMed and Web of Science and included the randomized controlled trials and clinical controlled trials, which met the criteria. A Bayesian network meta-analysis (NMA) for SNA, SNB, ANB, SN-MP and Wits appraisal was performed in R software using a random consistency model. The additional analyses included node-splitting analysis, statistical heterogeneity analysis, sensitivity analysis and ranking probability by SUCRA. A total of 598 articles were initially obtained; 13 articles involving 482 individuals were eventually included. Among the five bone-anchored maxillary protraction protocols, the largest increment in SNA and Wits appraisal was observed in the BAMP group and BAC3E group, respectively; the SAFM, BAC3E and BAMP groups showed similar capability in terms of changes of ANB; least clockwise rotation of the mandible was found in the BARME-ME group, followed by the BAMP group; dental compensation appears to be most pronounced in the BAC3E group; and intermaxillary traction seems to reduce the lingual inclination of lower incisors and even cause labial inclination. The SAFM, BAMP and BAC3E groups seem to be advantageous in the improvement of the maxillo-mandibular relationship, followed by the BARME-FM and BARME-ME groups. The findings of this study should be interpreted with caution as only short-term effects were compared and the quality of evidence ranged from very low to moderate. More RCTs with high-quality and long-term investigation are needed.

A combined Surgical-Orthodontic treatment in skeletal Class II malocclusion patients

Skeletal Class II malocclusion with mandibular deficiency is one of the most common problems that patients seek treatment. Adult patients with severe skeletal Class II malocclusion need orthognathic surgery for successful treatment. Bilateral sagittal split osteotomy (BSSO) is the most often preferred technique for these patients. This case report briefs about two male patient of age 24 years presented with Class II Skeletal relation, mesoprosopic facial form, horizontal growth pattern and Angle’s Class II div 1 malocclusion who were treated with Bilateral sagittal split osteotomy (BSSO) mandibular advancement. The ideal anteroposterior relation was established along with a Class I molar, incisor, canine relationship and ideal overjet, overbite and the overall facial esthetics were significantly improved. Combined surgical-orthodontic treatment aims to obtain a more harmonious facial, skeletal, dental and soft tissue relationship with an added patient self esteem.

Treatment of a Growing Patient with Skeletal Class III Malocclusion Using Face Mask and Maxillary Skeletal Expander

Face mask treatment with a rapid palatal expander is common in children with Class III malocclusion and maxillary deficiency. However, it can cause anchorage loss and dental side effects. To overcome these disadvantages, the use of skeletal anchorage such as miniplates in the infrazygomatic crest area or palate has been reported. This clinical case report presents face mask treatment in skeletal Class III adolescent with maxillary skeletal expander (MSE). MSE has been developed for the maxillary expansion in adults, but it can be used as a skeletal anchorage for face mask treatment in children. The post-treatment profile was significantly improved without any dental side effects.

Sexual dimorphism in the long-term stability (10 years) of skeletal Class III treatment

BackgroundClass III malocclusion is associated with high sexual dimorphism, especially in individuals older than 13 years of age, with significant differences in growth between males and females during the pubertal and postpubertal stages, and in adulthood. The aim of this research was to examine differences between males and females in long-term stability (10 years) of treatment for skeletal Class III malocclusion.MethodsThirty patients (15 males and 15 females) with skeletal Class III malocclusion, who had been treated with rapid maxillary expansion (RME) combined with face mask protraction followed by fixed appliances, were selected sequentially. Thirty patients (15 males and 15 females) with skeletal Class I and mesofacial patterns treated only with fixed appliances for dental problems served as the control group. Differences between groups and sexes were evaluated using lateral cephalograms taken at the start of treatment (T0), immediately after the end of treatment (T1), and after 10 years (T2). The long-term treatment success rate was calculated.ResultsTen years after Class III treatment, overjet and overbite relapse occurred similarly in females (− 0.68 ± 0.7 mm; − 0.38 ± 0.75 mm, respectively) and males (− 1.09 ± 1.47 mm; − 0.64 ± 0.9 mm, respectively); the ANB angle and Wits appraisal became significantly more negative in males (− 1.37 ± 1.06°; − 2.7 ± 2.53 mm) than in females (− 0.18 ± 1.26°; − 0.46 ± 1.94 mm). The success rate was 73.3% in males and 80% in females.ConclusionsSignificant differences in the long-term stability of Class III treatment outcomes have been found between males and females, with a larger skeletal Class III relapse and lower long-term success rates in males.

Three-dimensional changes of oropharyngeal airway after orthodontic extraction treatment in skeletal class Ⅰ adolescents

Objective: To explore the effect of extraction on upper airway in skeletal class Ⅰ adolescents. Methods: According to random number table method, 30 skeletal class Ⅰteenagers who underwent orthodontic straight wire treatment were selected randomly in Department of Orthodontics, School of Stomatology, The Fourth Military Medical University between January 2016 and December 2019. There were 13 males and 17 females, aged (13.7±1.5) years (12.2-15.7 years). In all patients, four first premolars were removed and the upper and lower anterior teeth were retracted under non-maximal anchorage (non-implant anchorage or face bow). The cone-beam CT (CBCT) data before and after orthodontic extraction treatments were studied. The three-dimensional model of the upper airway was reconstructed and segmented, and the relevant indexes of oropharyngeal volume and cross-sectional area were measured. Cephalograms was generated to measure tooth-jaw indexes and hyoid position. The changes of each index before and after orthodontic treatment were compared. The correlation between the changes in the volume or sectional area of the oropharyngeal airway and the changes in the dental and maxillary indexes and the hyoid position was tested. Results: Compared with those before treatment, palatopharyngeal volume, glossopharyngeal volume, oropharyngeal total volume, and minimum transection area increased by 632 (558) mm3, 758 (549) mm3, 1 454 (955) mm3 and 14 (29) mm2 respectively, and statistically significant differences were found (P<0.05). The minimum oropharyngeal area was mostly located in the glossopharynx. The cross-sectional area and the maximum anterior-posterior diameter of uvula tip decreased by (4±10) mm2 and (0.4±0.8) mm respectively, and the difference was statistically significant (P<0.05). There was no significant difference in the maximum lateral diameter before and after treatment (P>0.05). The ratio of the maximum antero-posterior diameter to the maximum lateral diameter at the uvula tip decreased from 0.589 (0.034) before treatment to 0.535 (0.047) after treatment (P<0.05), indicating that its shape tends to be more elliptic after treatment. In addition, the change of cross-sectional area at the apex of uvula was positively correlated with the changes of mandibular central incisor lip inclination and the distances from the upper and lower central incisor points to the Frankfort plane perpendicular to the sella point (UI-FHp and LI-FHp) (P<0.05). Conclusions: The impact of orthodontic extraction treatment on oropharyngeal airway was generally small in skeletal class Ⅰ adolescents. However, it could change the shape of the airway to some extent. The change of airway cross-sectional area at the uvula tip was positively correlated with the retraction of anterior teeth.

Maxillary anterior root resorption in Class II/I malocclusion patients post fixed orthodontic treatment

Background: Previous studies on root resorption were reviewed by panoramic radiographs. Cone-beam computed tomography (CBCT) showed that 41.5% of teeth experienced resorption when panoramically examinated, while 68% of teeth experienced resorption when the examination method used was CBCT. Root resorption occurs in the maxillary central incisor (as much as 74%) and in the maxillary lateral incisor (as much as 82%). The maxillary canines have the most resorption, followed by the lateral maxillary incisors. Purpose: The aim of this study was to determine the differences of apical resorption in anterior maxillary teeth before and after orthodontic treatment in skeletal Class I/II cases of extraction. Methods: Samples from this study were the results of panoramic photographs of 50 patients treated by fixed orthodontic appliances at the Dental and Oral Hospital Airlangga University. These were selected according to the sample criteria. The evaluation method consists of measuring root and crown lengths with a digital application (RadiAnt DICOM Viewer). Subsequently, the measurements were evaluated using CBCT images. Results: The data were statistically analysed using normality tests with Shapiro–Wilk and Kolmogorov–Smirnov tests. Based on the results of paired sample tests, it was found that every treatment group had significant differences in the average length of the crowns and roots, with a result of p=0.000 (p&lt;0.05). Conclusion: The use of CBCT is considered quite effective and accurate in evaluating root resorption compared to panoramic photographs.

Evaluation of long-term hard tissue relapse following surgical–orthodontic treatment in skeletal class II patients: A systematic review and meta-analysis

This systematic review and meta-analysis was performed to evaluate the long-term hard tissue stability and relapse factors following surgical–orthodontic treatment in skeletal class II patients. A literature search was conducted using Embase, Cochrane Central, Web of Science, and PubMed, yielding 3184 articles published up to January 2019. Risk of bias was assessed following the Cochrane handbook. Ten articles met the inclusion criteria. A total of 1079 patients were followed up for 5–13 years. The qualitative findings showed a variety of extrinsic and intrinsic factors affecting long-term stability. Meta-analysis for the amount and direction of cephalometric landmark displacement in the vertical and sagittal planes showed significant angular increases of ANB and backward relapse of SNB, however within the clinically acceptable range of 4°. In relation to linear measurements, the mean differences in all landmarks were within the clinically acceptable range of 2mm except for gonion. In conclusion, this systematic review showed multiple intrinsic and extrinsic factors responsible for relapse. However, the outcomes of the meta-analysis are limited due to the heterogeneity of data, small number of studies, and inconsistent methods of evaluation. Further high-quality studies utilising standardised three-dimensional methodologies are required to improve the level of evidence.

Dentoskeletal effects following Twin-Block functional treatment of skeletal Class II malocclusion accompanied with low-level laser therapy: A prospective clinical evaluation

Dentoskeletal effects following Twin-Block functional treatment of skeletal Class II malocclusion accompanied with low-level laser therapy: A prospective clinical evaluation

Long-term maxillary three dimensional changes following maxillary protraction with or without expansion: A systematic review and meta-analysis

Background/purposeMaxillary protraction with or without expansion appears to be an effective orthopedic treatment in skeletal class III growing patients, but the long-term effect on maxilla changes is less clear. The aim of this meta-analysis was to evaluate long-term three dimensional skeletal effects on maxilla through face mask (FM) with or without rapid maxillary expansion (RME) in skeletal CIII growing patients.Materials and methodsWe searched database including PubMed, Science Direct, Embase and Web of Science through Feb 2020. Inclusion criteria were randomized controlled trials or cohort studies recruiting growing patients who received maxillary protraction and/or expansion and comparing the treatment groups with untreated controls. The follow-up periods were more than 3 years. Risk of bias was assessed using the Cochrane tools (RoB2.0 and ROBINS-I). GRADE was used to qualify the evidence.ResultsThis meta-analysis included 6 studies comprising 327 participants in total. No statistically significant changes were observed on the degree of Sella-Nasion-A point (SNA) in the treated groups when compared with the untreated controls. However, significant increase on maxillary rotation degree (mean difference: 8.20, 95% CI = 6.87–9.53, p < 0.001) and maxillary base width (mean difference: 2.27, 95% CI = 1.39–3.15, p < 0.001) in the treated groups, if compared with untreated controls.ConclusionOur results indicated that FM and FM/RME treatments might not be long-term effective on correcting maxillary anteroposterior hypoplasia in growing patients. Additionally, more long-term studies are still necessary to further assess its skeletal benefits on maxilla in vertical and transverse dimension.