Three-dimensional evaluation of skeletal and dental changes in patients with skeletal class III malocclusion and facial asymmetry after surgical-orthodontic treatment.

OBJECTIVE: To evaluate skeletal and dental changes in patients with skeletal Class III malocclusion and facial asymmetry after surgical-orthodontic treatment using cone-beam computerized tomography (CBCT). METHODS: This study included forty adult patients diagnosed with skeletal Class III malocclusion and asymmetry who underwent either isolated mandibular surgery or bimaxillary surgery. CBCT scans were taken before treatment (T0), at the completion of presurgical orthodontic treatment (T1) and after treatment (T2). Mimics 17.0 and 3-Matics 7.0 were used to measure skeletal and dental parameters. Skeletal and dental changes within each group from pretreatment to posttreatment were assessed, and Pearson correlation analysis was used to analyze the correlations among skeletal changes. RESULTS: The three-dimensional changes in condylar position were insignificant after surgical-orthodontic treatment in either group (P > 0.05). However, in the one-jaw surgery group, there were significant backward rotations of the condyle and ramus on the nondeviated side (P < 0.05), and the condyle on the deviated side rotated inward and forward significantly in the two-jaw surgery group (P < 0.05) at T2. There were no significant differences in the changes in the total alveolar bone thickness of bilateral first molars during dental decompensation (P > 0.05). The ratio between the buccal and the total bone thickness around the maxillary first molar on the deviated side decreased significantly at T1, as did those around the mandibular first molar on the nondeviated side (P < 0.05). CONCLUSIONS: Condylar angulations were less stable after treatment (7 to 9 months after surgery) in both the one-jaw and the two-jaw surgery groups, while condylar displacements were insignificant. In addition, orthodontists should keep a watchful eye to the relative position of the root in the alveolar bone during tooth decompensation.

Three-dimensional assessment of soft tissue changes associated with bone-anchored maxillary protraction protocols.

INTRODUCTION: The aim of this study was to assess the 3-dimensional soft tissue changes in growing Class III patients with maxillary deficiency associated with 2 bone-anchored maxillary protraction protocols in relation to an untreated control group of Class III patients. METHODS: Growing skeletal Class III patients between the ages of 10 and 14 years participated in this study. In group 1 (n = 10), skeletally anchored facemasks were used with miniplates placed at the zygomatic buttress. In group 2 (n = 10), the patients were treated with Class III elastics extending from infrazygomatic miniplates in the maxilla to symphyseal miniplates in the mandible. Group 3 (n = 10) was an untreated control group. Three-dimensional stereophotogrammetry images were acquired before and after treatment, and then superimposed and analyzed. In addition, lateral cephalometric radiographs were analyzed. RESULTS: The maxilla moved forward significantly in groups 1 and 2 compared with the untreated control group (group 1, 4.87 mm; group 2, 5.81 mm). The 3-dimensional soft tissue analysis showed significant treatment effects; the major changes were observed in the upper lips, cheeks, and middle of the face, which had a significant positive sagittal displacement in both treatment groups. The lower lip and chin area showed significant negative sagittal changes that indicated that the soft tissue growth in this area was restrained with backward displacement especially in group 1 more than in group 2. CONCLUSIONS: The 2 bone-anchored maxillary protraction protocols effectively improved the Class III concave soft tissue profile.

Mandibular condylar hyperplasia: clinical, histopathological, and treatment considerations.

Condylar hyperplasia is a rare disorder characterized by an increased volume of the condyle, ramus, and mandibular body leading to facial asymmetry. We present three cases of condylar hyperplasia: two women and one man, age range 27 to 34. Clinically, all three patients showed a deviation of the mandible to the opposite side and a protruded position of the chin, hypertrophy of the lower border of the mandible, combined with an elongation of the mandibular ramus, open-bite on the deformed side, and cross-bite on the opposite side. In all three cases, scintigraphy showed an increased uptake. Radiography and CT scanning confirmed the clinical diagnosis and patients were subjected to surgery, comprising high condylectomy on the affected side with access in the pre-tragus area. The surgical piece sent to the Institute of Pathological Anatomy for histological examination revealed a nonuniform picture, in terms of both the depth of cartilage islands and the thickness of the fibrous layer covering the joint surface. Common to all three cases, however, was the apparent evolution of fibrous tissue to cartilage, and of this to compact bone tissue. At two-four years, all cases have maintained a good occlusal response. The asymmetric deformity of the mandible resulting from the rare condition of hemimandibular hyperplasia is presented and the clinical, histopathological and therapeutic aspects discussed.

Histomorphometric analysis of unilateral condylar hyperplasia in the temporomandibular joint: the value of the condylar layer and cartilage island.

This study aimed to describe the condylar layer and cartilage island in subjects with unilateral condylar hyperplasia (UCH). Five individuals (15-18 years old) with a diagnosis of UCH, treated in a university hospital in Temuco, Chile, were included. The analysis examined the presence, extension, and thickness of the layers on the condylar surface, the number, depth, and area of the cartilage islands, and the argyrophilic proteins of the nucleolar organizer region (AgNOR) score. Statistical significance was set at P<0.05. The fibrocartilaginous layer was thickest (0.13±0.05mm) and the joint layer was thinnest (0.07±0.01mm) (P<0.05). With respect to the number, depth, and area of the islands, case 1 presented the highest values, followed by case 2; the cartilage island was related to the fibrocartilaginous layer (P<0.05). All cases had AgNOR proteins in the proliferative and fibrocartilaginous layers, as well as the islands with the greatest presence of chondrocytes (P=0.245). A relationship was observed between the histopathological alterations in the different layers on the condylar surface and the thickness of the fibrocartilaginous layer, as well as the thickness of the latter and the number, depth, and area of the cartilage islands in the trabecular bone.

Accuracy Assessment of Virtual Surgical Planning Comparing 3D Virtual Surgical Planning and Post-Operative CBCTs in Surgical Skeletal Class III Cases: A Retrospective Study

ABSTRACT Objective: To evaluate the accuracy of Virtual Surgical Planning (VSP) comparing VSPs and post-operative CBCT scans in patients undergoing bimaxillary orthognathic surgery of severe Skeletal Class III malocclusion. Material and Methods: Twenty-three patients (9 males and 14 females, mean age 24.1 ± 7.0 years) were selected and submitted to bimaxillary orthognathic surgery. Pre-operative VSPs and post-operative CBCTs were compared using both linear (taking into account four skeletal and six dental landmarks, each one described by the respective coordinates) and angular measures (seven planes in total). The threshold discrepancies for post-operative clinical acceptable results were set at ≤2 mm for liner and ≤4° for angular discrepancies. The mean difference values and its 95% confidence interval were identified, comparing which planned and which obtained in absolute value. Results: There were significant statistical differences for all absolute linear measures investigated, although only two overcome the linear threshold value of 2mm in both X and Y-linear dimensions. Linear deviations in Z-linear dimension do not reach statistical significance. All 12 angular measures reach the statistical significance, although none overcome the threshold angular value of 4°. Angular deviation for roll register the higher accuracy in contrast to pitch and yaw. Conclusion: Virtual surgical planning is a reliable planning method to be used in orthognathic surgery field; as a matter of fact, although some discrepancies between the planned on the obtained are evident, most of them meet the tolerability range.

3D soft tissue changes in facial morphology in patients with cleft lip and palate and class III mal occlusion under therapy with rapid maxillary expansion and delaire facemask.

AIM: Rapid Maxillary Expansion (RME) and Delaire facemask are a well-established treatment method for patients with cleft lip and palate and Class III malocclusion. Several roentgenocephalometric studies on skeletal effects of this therapy are known. However, there are no systematic studies on soft tissue changes. The aim of this study was to analyze three-dimensionally the soft tissue changes in facial morphology of children with cleft lip and palate and Class III malocclusion under therapy with RME and Delaire facemask. PATIENTS AND METHOD: A prospective longitudinal clinical trial was undertaken. 29 children between 4.1 and 6.4 years were divided into four groups: eight patients with unilateral cleft lip and palate (group 1), six patients with isolated cleft palate (group 2), eight patients with Class III malocclusion (group 3). The mean treatment period with RME and Delaire mask was 8.2 months. Seven untreated children with no need of orthodontic treatment were chosen as the control (group 4). Two 3D images, one at the beginning and one at the end of the study, were generated with the DSP 400((c)) imaging system. Both images were superimposed ten times and measured ten times. RESULTS: We detected significant forward rotation and forward displacement of the soft tissue in the lower midface with the dentoalveolar areas in all patient groups. No significant asymmetric forward displacement of the soft tissue in the maxilla could be verified in the lower or upper midface, not even in the unilateral cleft lip and palate patients. Among the groups, the Class III malocclusion patients showed greater maxillary soft tissue changes. CONCLUSION: The RME and the Delaire facemask demonstrated the greatest effectiveness in the lower midface soft tissue in terms of forward displacement and forward rotation in the cleft lip and palate patients, particularly in the Class III patients. The 3D data allowed us to discriminatively interpret the effects of the orthopedic mask on the entire maxillary complex and maxillary alveolar process. In the unilateral cleft lip and palate patients, there was descriptively both symmetric and asymmetric advancement of the midface soft tissue.

Analysis of soft tissue changes after genioplasty in skeletal class III dentofacial deformity.

PURPOSE: The purpose of this study was to measure the anteroinferior changes and the degree of vertical changes to facilitate the prediction of treatment outcome in patients undergoing genioplasty only, genioplasty with bilateral sagittal split ramus osteotomy (BSSRO), genioplasty, or BSSRO and Lefort I osteotomy. MATERIALS AND METHODS: Serial cephalometry was performed on 25 patients at 1-year follow-up after genioplasty, to assess skeletal changes and relapse. Surgery was performed using conventional techniques. RESULTS: The mean ratio was 0.9:1 of soft tissue to skeletal movement at pogonion, but the average difference between hard and soft tissue was large; thus, the prediction of anteroposterior soft tissue changes was quite inaccurate. CONCLUSION: We observed a good correlation between the amount of hard versus soft tissue change with surgery in the horizontal direction, but a poor correlation in the vertical plane.

Soft tissue facial volumes and shape in skeletal Class III patients before and after orthognathic surgery treatment.

BACKGROUND: To obtain the best surgical results in orthognathic surgery, treatment planning and the evaluation of results should be performed on measurable three-dimensional reproductions of the face of the patients, and compared to reference subjects. METHODS: Seven women aged 18-35 years, all with a skeletal Class III and mandibular asymmetry, were assessed both before (on average, 2 months) and after (on average, 10.7 months) surgical intervention (mandibular reduction by sagittal split osteotomy and LeFort I maxillary advancement). The three-dimensional coordinates of 50 soft tissue facial landmarks (face, eyes, nose, mouth and lips, ears) were collected with a noninvasive, electromagnetic digitizer; facial volumes were estimated, and compared to reference values collected in 87 healthy women of the same age and ethnic group. Inter-individual modifications in facial shape were also assessed. RESULTS: Before surgery the patients had smaller faces than the reference women, with larger lower lips and noses. A large within-group variability was found. Surgical treatment significantly reduced total facial volume and mandibular volume, increased total and upper lip volumes (Student's t test, p<0.05), and made all values more homogenous within the group. Shape differences were significantly larger before than after surgery. On average, right side gonion was the landmark that moved the most, closely followed by menton, while the tragi and ala nasi moved the least. The three-dimensional approach used in this study enabled quantitative evaluation of the final soft tissue results of surgery, without submitting the patients to invasive procedures.

Comparação da anatomia transversal de mandíbula de indivíduos classe III com e sem fissura labiopalatina por meio de tomografia de feixe cônico / Comparison of transverse dimension of class III mandible with and without cleft lip and palate using conical beam tomography

A relação entre a anatomia mandibular e a ocorrência de fratura indesejada de mandíbula na osteotomia sagital é alvo de estudos. A literatura mostra a existência de diferentes conformações anatômicas da mandíbula, porém não há estudos nessa área direcionados a indivíduos com fissura labiopalatina. Também não há na literatura estudos que mostrem as diferenças morfológicas da mandíbula relacionadas a secção transversal entre primeiro e segundo molar e sua relação com implicações na cirurgia ortognática. O objetivo do presente estudo foi avaliar a morfologia da região entre primeiro e segundo molar inferior e classificar a prevalência dos tipos mandibulares dentro de cada grupo. Foram realizadas análises e medições das reformatações das tomografias da região de molares, bilateralmente, de indivíduos Classe III, com fissura labiopalatina unilateral (Grupo FLP) submetidos à cirurgia ortognática para recuo mandibular no Hospital de Reabilitação de Anomalias Craniofaciais e de indivíduos Classe III, sem fissura (Grupo Controle) do banco de dados do Departamento de Cirurgia e Estomatologia da Faculdade de Odontologia de Bauru. Foram realizadas duas medidas lineares e uma medida angular. As hemimandíbulas foram classificadas segundo a profundidade da fossa mandibular em: Tipo a - 0 e 1mm; Tipo b - 1,1 e 2mm; Tipo c - 2,1 e 3mm; Tipo d - maior que 3,1mm. Foram analisadas 200 hemimandíbulas no Grupo FLP e 100 no Grupo Controle. Os resultados mostraram que não houve diferença entre os grupos quanto a classificação das mandíbulas segunda a profundidade da fossa, sendo o grupo b o mais prevalente, mas houve diferença em relação a angulação e a altura da mandíbula. Também foi notada uma relação entre a altura da mandíbula e a sua angulação em ambos os grupos. Assim, pode ser observada a grande variação morfológica dessa região, tanto para o grupo com fissura labiopalatina, quanto para o grupo controle. (AU)

The relationship between a mandibular anatomy and an occurrence of an undesirable jaw fracture in a sagittal osteotomy is the subject of the studies. The literature shows an existence of different anatomical conformations of the mandible, but there are no studies on the area directed to individuals with cleft lip and palate. There are not in the literature, studies that show a prevalence of mandibular types and the relation of these anatomical variations with orthognathic surgery implications. The objective of the present study was evaluate the morphology of the region between the first and second lower molars and analyze the prevalence of mandibular types within each sample group. Analyzes and measurements of the CT scans were performed bilaterally on Class III patients with unilateral cleft lip and palate (CLP Group) submitted to orthognathic surgery for mandibular retreatment at the Hospital for Rehabilitation of Craniofacial Anomalies and Class III individuals, without Fissure (Control Group) of the database of the Department of Stomatology of the Faculty of Dentistry of Bauru. Two linear measurements and one angular measurement were performed. The half of mandibles were classified according to the depth of the mandibular fossa in: Type a - 0 and 1mm; Type b - 1.1 and 2mm; Type c - 2.1 and 3 mm; Type d - greater than 3.1mm. Two hundred half of mandibles were analyzed in the CLP Group and 100 in the Control Group. The results showed that there was no difference between the groups regarding the classification of the mandibles according to the depth of the fossa, being group b the most prevalent, but there was difference in relation to the angulation and the height of the mandible. It was also noted a relationship between the height of the mandible and its angulation in both groups. Thus, the great anatomical variation of this region can be observed, both for the group with fissure and for the group without fissure. (AU)

Avaliação das vias aéreas superiores por meio de tomografia computadorizada Cone-beam em pacientes Classe III submetidos à cirurgia bimaxilar / Evaluation of the upper airways by means of Cone-beam computed tomography in Class III patients submitted to bimaxilar surgery

Introdução: Dependendo da magnitude da má oclusão de Classe III, esta é uma alteração difícil de ser tratada apenas com a correção ortodôntica. Tanto as cirurgias de recuo mandibular quanto as bimaxilares promovem uma melhora na oclusão, na função mastigatória e na estética facial, ao corrigirem as posições da mandíbula e/ou maxila, mas um importante aspecto da cirurgia ortognática, que não pode ser negligenciado, são os efeitos que os movimentos esqueléticos das bases ósseas podem provocar na região das vias aéreas, ao alterar a posição do osso hióide e da língua. O estreitamento das vias aéreas superiores (VAS) pode comprometer o sono dos pacientes submetidos à correção cirúrgica e predispor ao desenvolvimento da apneia/hipopneia obstrutiva do sono (AOS). Objetivos: O presente trabalho tem como objetivo avaliar as alterações de volume e área axial mínima do espaço aéreo faringeo em pacientes com má oclusão de Classe III esquelética, submetidos à cirurgia ortognática bimaxilar, pela técnica de osteotomia Le Fort I da maxila e osteotomia sagital bilateral da mandíbula. Material e Métodos: As avaliações foram feitas em tomografias computadorizadas Cone-beam, utilizando-se o Programa Dolphin Imaging 11.7. As tomografias de 50 pacientes, de ambos os sexos, com média de idade de 33,40 (± 9,38) anos, foram analisadas nos períodos pré e pósoperatório e as medidas de volume e área axial mínima foram mensuradas. Foi utilizado o teste t pareado e os testes foram realizados utilizando-se o programa Statistica 7.0, adotando-se um nível de significância de 5%. Resultados: ao calcular o erro do método, não foram encontrados erros casuais e nem sistemáticos (p> 0,05 em todas as medidas). As cirurgias bimaxilares para correção da Classe III esquelética promoveram um aumento de 16,68% (±22,61) no volume e 23,58% (± 31,46) na área axial mínima. Conclusões: Mesmo que os efeitos da cirurgia de avanço maxilar e recuo mandibular sobre as vias aéreas não sejam completamente previsíveis, podemos observar que a maioria dos pacientes não apresentaram prejuízos na anatomia faringeana que resulte em diminuição do volume aéreo e área axial mínima, predispondo-o ao desenvolvimento da AOS.(AU)

Introduction: Depending on the extend of Class III malocclusion, it becomes difficult to be treated only with orthodontic correction. Both mandibular setback surgery as bimaxillary surgery, promote an improvement in occlusion, masticatory function and facial aesthetics, correcting the position of the mandible and/or maxilla. But an important aspect of orthognathic surgery that cant be overlooked, are the effects that the skeletal movements of the bone bases causes in the airway space, since they change the position of the hyoid bone and tongue. The narrowing of the pharingeal airway space (PAS) may impair the patient's sleep and predispose to the development of obstructive sleep apnea (OSA). Purpose: This study aims to evaluate surgical changes in the airway volume and minimal cross-sectional area in the pharyngeal airway space (PAS) in patients with skeletal Class III malocclusion, submitted to bimaxillary surgery, using a Le Fort I maxillary osteotomy and bilateral sagittal split ramus osteotomy technique. Material and Methods: The evaluations were made through Cone-beam computed tomography (CBCT), using Dolphin Imaging program version 11.7. The CT scans of 50 patients of both genders, with a mean age of 33.40 (± 9.38), were analyzed pre and postoperatively and volume and minimum axial area were measured. Paired t test was used and tests were performed using Statistica 7.0 software, adopting a 5% significance level. Results: Method error were done and no random or systematic errors were found (p> 0.05 for all measures). Bimaxillary surgery for skeletal Class III correction promoted an increase of 16.68% (± 22.61) in volume and 23.58% (± 31.46) at the minimum axial area. Conclusion: Even if the effects of the maxillary advancement and mandibular setback surgery on the airway are not completely predictable, we observed that most patients didnt have pharyngeal airway anatomy damage, that could result decreased on airway volume and minimum axial area predisposing to OSA development.(AU)

Treatment of a Class I malocclusion with severe bimaxillary protrusion.

This report describes the treatment of a 20-year-old woman from Nigeria who had severe bimaxillary dentolveolar protrusion. The main issue in determining the appropriate treatment plan was the severity of the dentoalveolar protrusion. Four first premolars were extracted to reduce lip procumbancy. The change in the patient's facial esthetics was dramatic. Significant retraction of the upper and lower lips was achieved, and lip eversion and dentoalveolar protrusion were significantly improved. As the lips were retracted, mentalis strain was reduced; this improved chin projection. This case report was presented at an AAO meeting as part of the ABO student case display. It was chosen by committee to be published in the AJO-DO.

Tratamento da maloclusão de classe III com o aparelho regulador de função 3 (RF-3) de frankel / Treatment ot class 111 malacclusian with the functian regulatar 3 appliance (RF-3) af frankel

Este trabalho teve como objetivo descrever um caso clínico de maloclusão classe 111 com mordida cruzada anterior e sobremordida profunda tratado com o Regulador de Função 3 de Frankel, acompanhado por três anos. Em cada fase foi obtida documentação ortodôntica e observou-se nas avaliaçôes clínicas e cefalométricas evolução favorável principalmente em relação à rotação horária da mandíbula, descruzamento da mordida e das grandezas cefalométricas no decorrer do tratamento, respectivamente concluímos que o Regulador de Função 3 de Frankel é um recurso efetivo no tratamento da maloclusão de classe 111 com mordida cruzada e sobremordida profunda em indivíduos em fase de crescimento.

This paper had as objective describes a clinical case of class 111 malocclusions with anterior crossbite and deep bite agreement with the Function Regulator 3 of Frankel, accompanied by 3 years. In each phase it was obtained orthodontic documentation and it was observed mainly in the clinical evaluations and cephalometric favorable evolution in relation to the mandible rotation, correction of the bite and of the cephalometric measures in elapsing of the treatment respectively. This work concluded that the Function Regulator 3 of Frankel is an effective resource in the treatment of the class 111 malocclusions with anterior crossbite and deep bite in individuais in growth phase.

Clase III por hipodesarrollo del maxilar superior / Class III by hipodevelopment of the upper jaw

La clase III tiene su origen en diferentes factores. Uno de ellos es el deficiente desarrollo del maxilar superior que se puede dar en los tres planos del espacio. Es frecuente observar dos tipos de deficiencia, una fundamentalmente transversal con menor afección horizontal y vertical, y la otra mayormente horizontal o vertical con dimensión transversal razonablemente normal. Ambos tipos poseen rasgos faciales, intraorales y funcionales particulares que los distinguen. Siempre que se presente hipodesarrollo del maxilar superior, independientemente del plano de mayor o menor afección, debe ser tratado en forma precoz, combinando fuerzas ortopédicas y ortodónticas. Los resultados del tratamiento deben cumplir objetivos dentarios, faciales y funcionales.

Cephalometric evaluation of Class III malocclusion by a modified Tweed-Merrifield analysis

A sample of cephalograms of 20 White Brazilian subjects (9 males, 11 females) of 17-36 years old, who presented Class III dental malocclusion was selected and traced. Results showed statistically significant differences among genders for FMIA, SNA, SNB, 1.NB, PFH, AFH, 1-NB and mandibular length. Anteroposterior jaw relation, as shown by SNA and SNB, presented a maxilla correctly positioned, as well as mandibular protrusion, which was related to a normal upper jaw length and an augmented lower jaw length. A vertical growth pattern prevailed, as evidenced by FMA, AFH, PHF and OCC.PL. Angle. The Z Angle, total chin and upper lip failed to clearly show any disturbance of facial esthetics and IMPA, 1.NA, 1-NA, 1.NB and 1-NB revealed dental compensation

Características morfológicas da sínfise mandibular e do incisivo inferior na má oclusão de classe III com indicação de recuo mandibular cirúrgico / Morphological characteristics of mandibular symphysis and lower incisor in class malocclusion requiring mandibular setback surgery

Este resumo teve como propósito definir as características morfológicas da sínfise mandibular e do incisivo inferior em pacientes com má oclusão de Classe III com indicação de recuo mandibular isolado. A amostra experimental foi constituida por 16 pacientes, na faixa etária média de 21 anos e 11 meses, apresentando má oclusão de Classe III represnetada por protusão mandibular. Para cada paciente foi realizada uma telerradiografia nas fase pré-tratamento, sendo comparada a um grupo controle constituído de indivíduos com oclusão normal. De acordo com a metodologia empregada, os resultados obtidos a partir de variáveis cefalométrricas angulares, lineares e proporcionais foram avaliados estatisticamente. Constatou-se uma compensação para a má oclusão referida, estando os incisivos inferiores e sínfise mandibular lingualizados, morfologicamente diferente dos indivíduos com oclusão normal. O processo alveolar e a região basal da sínfise mandibular e as corticais ósseas vestibular das regiões referidas apresentaram-se lingualizadas, considerando-se o plano mandibular ocasionando uma curvatura menos pronunciada entre a sregiões alveolar e basal propriamente ditas e suas corticais óssea vestibular. Nestes pacientes, o mento ósseo apresnetou-se mais pronunciado e o processo alveolar, a porção basal e a altura da sínfise mandibular apresentaram-se diminuídos. Já a latura da sínfise não apresentou diferença estatisticamente significante em relação ao normal. O incisivo inferior apresentou diferença significante em relação ao processo alveolar