Correlations Between Mandible Condylar Structures and External Ear Deformities in Hemifacial Microsomia With Three-Dimensional Analysis.

ABSTRACT: This study aimed to explore correlations between mandible and ear deformities and quantitative volumetric relations between condylar structures and external ear in hemifacial microsomia. The authors reconstructed three-dimensional craniofacial models from 212 patients with unilateral hemifacial microsomia (the unaffected side as the controls). Patients were evaluated by Pruzansky-Kaban and Marx classification, and divided into 3 age groups (0-6, 7-12, and >12 years of age). The mandible condylar structures, including condyle and the condylar skeletal unit, were selected (except the classification of the mandibular or ear deformities (M3)). Along with the external ear (except the classification of the mandibular or ear deformities (E4)), their volumes were measured and analyzed. Spearman correlation coefficient analysis was applied. There was a positive correlation between the mandible and ear deformities (r = 0.301, P   <  0.001). Either between the condyle and external ear ( P  = 0.071-0.493) or between the condylar unit and external ear ( P  = 0.080 - 0.488), there were no volumetric relations on the affected side, whereas on the unaffected side were (r = 0.492-0.929 for condyle, r = 0.443-0.929 for the condylar unit, P  < 0.05). In most cases, the condylar structures of the classification of the mandibular or ear deformities (M2b) were significantly smaller than the classification of the mandibular or ear deformities (M2a). Results suggested deformities of mandibular condylar structures and ear did not correlate, although deformities of mandible and ear did. The condylar deformity might develop independently from microtia and be more severe within relatively more abnormal temporomandibular joints.

Pediatric unilateral isolated choanal atresia is not associated with mandibular condyle hypoplasia.

PURPOSE: We hypothesized that the ontogeny of unilateral isolated choanal atresia involves a field defect manifesting as ipsilateral mandibular condylar hypoplasia. The topic is important because the mechanism of the unilateral isolated choanal atresia is unknown. MATERIALS AND METHODS: Retrospective self-controlled case series. We included 20 patients (2 males and 18 females, ages 2 weeks to 13 years) with unilateral isolated non-syndromic choanal atresia. We studied their high-resolution computed tomographic scans. Two otolaryngologists measured the largest cross-sectional area of the mandibular condyle in the axial plane perpendicular to the posterior border of each mandibular ramus independently. Statistical significance and inter-rater agreement were calculated with paired Wilcoxon rank sum test and Spearman's non-parametric correlation coefficient respectively. RESULTS: Cross-sectional areas of the condyles ipsilateral to the choanal atresia were not statistically different than those of the contralateral condyle (P = 0.27). Inter-observer agreement of condyle areas was excellent: Spearman's r = 0.85 on the right and r = 0.94 on the left. CONCLUSIONS: In this cohort of children with the rarity of isolated non-syndromic unilateral congenital choanal atresia, no associated mandibular condyle hypoplasia was found. The data suggest that the underlying ontogeny was unlikely attributable to a field defect.

Correlation between patient complaint, temporomandibular disorder diagnosis and mandible head morphology

The aim of this study was to evaluate the correlation between patient complaints, clinical diagnosis of temporomandibular disorder (TMD) based on the diagnostic criteria for TMD, and morphology of the mandibular condyle obtained by cone-beam computed tomography (CB-CT). Data were collected from 40 patients. The anatomy of the mandibular condyle was assessed using CB-CT, the diagnosis of TMD according to diagnostic criteria for TMD, and patients' complaints was registered at the appointment. Data were explored and all statistical references were completed in bicaudal tests, with 95% confidence level (α=0.05). The Chisquared test was used with Bonferroni correction (z-tests). Main complaints found were grouped as muscular, articular, muscular and articular, or headache and articular symptoms. Clinical diagnosis of TMD involved myalgia, local myalgia, myofascial pain, myofascial pain with reference, myofascial pain with arthralgia, arthralgia, or disc displacement with reduction. At least one joint showed condylar flattening, erosion, sclerosis, or osteophytes. No correlation was observed between main complaints, clinical diagnosis, and morphology of the mandibular condyle in all comparisons. The findings suggest that due to the absence of clinical and morphological correlation, CB-CTs should be requested only in specific cases, when doubt remain after careful TMD diagnosis, to avoid their over-indication(AU)

Reabsorción Condilar como Complicación Postoperatoria en Pacientes Sometidos a Cirugía Ortognática. Revisión Narrativa / Condylar Resorption as a Postoperative Complication in Patients Undergoing Orthognathic Surgery. Narrative Review

RESUMEN: La reabsorción condilar como complicación postoperatoria en cirugía ortognática es una causa frecuente de recidiva de anomalías dentomaxilares, existiendo diversos factores que se relacionan con su aparición. El objetivo de este estudio fue describir mediante una revisión narrativa la reabsorción condilar como complicación postoperatoria en cirugía ortognática. Se realizó una búsqueda electrónica de la literatura en las bases de datos electrónicas PubMed, EBSCO, TripDatabase y Epistemonikos sin límite de años, en idioma inglés y español, incluyendo revisiones sistemáticas, ensayos clínicos y estudios observacionales. Se excluyeron reportes de casos, estudios en animales y aquellos que no relacionaran la complicación con cirugía ortognática. Se evaluaron los estudios según grado de recomendación y calidad de reporte. Veintiún artículos fueron seleccionados según los criterios de selección establecidos en esta revisión. La literatura reportada sugiere que la reabsorción condilar es una patología de frecuencia relativa en pacientes postoperados de cirugía ortognática (1,4-32 % de los casos) y que está asociada a factores de riesgo preoperatorios tales como género, edad, tipo de anomalía dentomaxilar y técnica quirúrgica utilizada. La reabsorción condilar es una complicación postoperatoria a cirugía ortognática que debemos considerar en la planificación del tratamiento e identificar pacientes con factores de riesgo. Luego de la intervención quirúrgica es de vital importancia realizar un seguimiento estricto a este tipo de pacientes e identificar de forma temprana cambios clínicos y radiográficos. Finalmente, es importante seguir investigando sobre esta materia para establecer criterios de prevención y diagnóstico, con mayor claridad.

ABSTRACT: Condylar resorption as a complication following orthognathic surgery is considered to cause dento-facial anomalies, relating to different pre and intra-operative factors. The aim of the research was to describe condylar resorption as a postoperative complication after orthognathic surgery. A review of the literature was made in four databases: PubMed, EBSCO, Trip database and Epistemonikos. The search was carried out without year limiting, articles in English and Spanish, including systematic reviews, observational studies and clinical trials. Exclusion criteria were applied for report cases, animal studies and articles that do not relate condylar resorption with orthognathic surgery. Quality of evidence and strength of the recommendations were assessed for the chosen studies. For this study 21 articles were selected following the inclusion criteria. The literature found reported that condylar resorption is a relatively frequent complication following orthognathic surgery (1.4-32 % of frequency) and that it can be associated with several factors such as genre, age, dento-maxillary anomaly and surgical technique. Condylar resorption is a complication that we must consider in the planning of orthognathic surgery, in order to identify risk factors and patients who are more likely to present this post-surgical complication. Following surgery, strict follow-up is a key factor to determine early clinical and radiographic changes. Finally, further research is needed to establish stronger prevention and diagnostic criteria.

Bifid mandibular condyles: A systematic review

BACKGROUND: Bifid mandibular condyle (BMC) constitutes an extremely rare disorder characterized by a duplication of the head of the mandibular condyle. Its prevalence ranges from 0.31% to 1.82% in the published literature. OBJECTIVES: The primary objective was to describe the main etiological, clinical and radiological characteristics of patients with BMCs and the existent treatment options. The secondary objective was to simultaneously include the characteristics of two new cases of BMC. MATERIAL AND METHODS: An electronic search in Pubmed (MEDLINE), Scopus and The Cochrane Library was carried out by two independent reviewers until April 2018. Prospective or retrospective cohort studies, case series and case reports describing clinical and/or radiological characteristics of patients with BMC were included. Registered variables were demographic, etiological factors, diagnostic exam, clinical characteristics and treatment options. The results from the articles selected were organized in a Table along with the characteristics of two new cases of BMC provided by the authors. RESULTS: From a total of 431 articles found in the initial search, 68 articles were finally included. This systematic review included 216 patients and 270 BMC with an average age of 30.6 (SD=14.7) years and a women:men ratio of 1.4:1. Mediolateral condylar orientation was the most prevalent position (80.1%). Among cases with known etiology, 40.8% of cases had a history of traumatism, while 55.9% did not present any relevant medical background. Half of the symptomatic cases had history of trauma. The most common symptoms were hypomobility (22.7%), arthralgia (18.1%), articular noise (17.2%) and ankylosis (17.6%). Active monitoring and manufacturing an occlusal splint were the most frequent treatment options. CONCLUSIONS: BMC may have congenital or traumatic etiology. Hypomobility and arthralgia are the most frequent symptoms and treatment options are often conservative

Bifid Mandibular Canal: A Case Review and Retrospective Review of CBCTs.

PURPOSE: This case presentation and retrospective review of cone-beam computed tomograms is to evaluate prevalence, classification, and demographics of bifid mandibular canals (BMC) to inform practitioners on this variation and avoid untoward complications due to failure to diagnose. MATERIALS AND METHODS: Two thousand one hundred thirty scans were evaluated by 2 oral and maxillofacial radiologists. BMCs were noted and classified according to Naitoh. Demographic data were also collected and analyzed. RESULTS: Twenty-eight patients were noted to have bifid mandibular canal, with an average age of 39 years (± 19.5), with no strong sex predilection. Patients (1.31%) were noted to have bifid canals. A greater percentage of patients were shown to have bilateral bifid canals (42.9%) versus either unilateral side (25% left, 32.1% right), but is statistically insignificant. Prevalence was greatest in types 1 and 3 (35.9% and 51.3%, respectively, P = 0.000011). Types 2 and 4 were much less common. CONCLUSION: BMCs are an important anatomic variation that has implications on any mandibular surgery, including implant surgery. Just more than 1% of patients have this variation, but failure to recognize this in a patient can result in poor outcome, as illustrated in the case presented.

Bifid mandibular condyles: A systematic review.

BACKGROUND: Bifid mandibular condyle (BMC) constitutes an extremely rare disorder characterized by a duplication of the head of the mandibular condyle. Its prevalence ranges from 0.31% to 1.82% in the published literature. OBJECTIVES: The primary objective was to describe the main etiological, clinical and radiological characteristics of patients with BMCs and the existent treatment options. The secondary objective was to simultaneously include the characteristics of two new cases of BMC. MATERIAL AND METHODS: An electronic search in Pubmed (MEDLINE), Scopus and The Cochrane Library was carried out by two independent reviewers until April 2018. Prospective or retrospective cohort studies, case series and case reports describing clinical and/or radiological characteristics of patients with BMC were included. Registered variables were demographic, etiological factors, diagnostic exam, clinical characteristics and treatment options. The results from the articles selected were organized in a Table along with the characteristics of two new cases of BMC provided by the authors. RESULTS: From a total of 431 articles found in the initial search, 68 articles were finally included. This systematic review included 216 patients and 270 BMC with an average age of 30.6 (SD=14.7) years and a women:men ratio of 1.4:1. Mediolateral condylar orientation was the most prevalent position (80.1%). Among cases with known etiology, 40.8% of cases had a history of traumatism, while 55.9% did not present any relevant medical background. Half of the symptomatic cases had history of trauma. The most common symptoms were hypomobility (22.7%), arthralgia (18.1%), articular noise (17.2%) and ankylosis (17.6%). Active monitoring and manufacturing an occlusal splint were the most frequent treatment options. CONCLUSIONS: BMC may have congenital or traumatic etiology. Hypomobility and arthralgia are the most frequent symptoms and treatment options are often conservative.

Mandibular Condylar Aplasia Treated with a Functional Appliance: A Five years Follow Up.

This report presents a follow up of a clinical case published five years ago by the same authors. In the previous report, the authors showed a young girl treated with a myofunctional appliance due to a mandibular condylar agenesia. After a traditional graft had failed, the patient successfully responded to the functional treatment by forming a mandibular condyle. In this new report, the authors are showing how the mandibular condyle has continued developing within normal limits and, the mandibular ramus has continued positively remodeling. The bone biology embedded in the biological process reported here is discussed by the authors.

Hemifacial microsomia (oculo-auriculo-vertebral spectrum) in an individual from the Teramo Sant'Anna archaeological site (7th-12th centuries of the Common Era, Italy).

BACKGROUND: This study is based in an analysis of the skeletal remains of an adult male from the Teramo Sant'Anna archaeological site (7th-12th centuries of the Common Era, Teramo, Italy). RESULTS AND DISCUSSION: The individual shows distinct abnormalities that principally involve asymmetric hypoplasia and dysmorphogenesis of the facial skeleton. The combination of these findings and the absence of abnormalities of the spine strongly suggest diagnosis of the congenital malformation known as hemifacial microsomia. This very heterogeneous syndrome affects primarily aural, ocular, oral and mandibular development. Despite the lack of clinical information and the absence of soft tissue, it was possible to perform a differential diagnosis for this palaeopathological case. Mastication was probably altered considering that the mandible is extremely asymmetric and lacks true condyles. The temporomandibular joints are present, but the right one is hypoplastic and abnormal in shape. There is evidence of bilateral dislocation, and the facial muscles are hypertrophic. CONCLUSIONS: This case represents an important contribution to the palaeopathological literature because this is an uncommon condition that has not been widely documented in ancient skeletal remains.

A study on etiopathogenesis and clinical features of multi-headed (bifid and trifid) mandibular condyles and review of the literature.

PURPOSE: The formations of second or more condylar heads are considered as rare anomalies. Fourteen multi-headed condyles (MHC) were presented; 13 of these were bifid mandibular condyles (BMC), whereas one exceptionally rare case was a trifid mandibular condyle (TMC). The TMC presented in this paper is the eighth case reported in the literature. In this paper, etiopathogenesis, types, and treatments are discussed. MATERIALS AND METHODS: Patients were classified according to their status, etiologies, gender, functions of the mandible, interocclusal distances, pathological conditions, types, and treatment received. RESULTS: BMCs were classified into two groups: type I BMCs were nontraumatic, nonsymptomatic, mediolateral, presumably developmental, and characterized by shallow grooves. Type II BMCs were traumatic and may have two subgroups. The first group of type II BMCs were mediolateral and Y-shaped. The second group of type II BMCs were characterized by two separate and anteroposteriorly located condyles. CONCLUSION: Treatment depended on patients' complaints. In this study, asymptomatic patients did not receive therapy, whereas patients with temporomandibular join internal derangement received medical treatment, and patients with ankylosis had surgical treatment.

Surgical Management of a Bilateral Bifid Condyle: Diagnosis, Three-dimensional Reconstruction, and Treatment - A Report of a Case and Review of the Literature.

Bifid condyle is a rare entity with a difficult diagnosis and usually identified as an incidental finding on routine radiographic examination. The etiology is not well known, possible causes may be developmental, traumatic, vascular, abnormal muscle pulling, nutritional, endocrinal, teratogenic, and infections. The orientation of the condylar heads can behelpful for the etiological diagnosis.This case report describes a 56-year-old woman who suffered from a unilateral, progressively increasing, radiating pain which intensified with the movement of the mandible and includes information about the diagnosis, management, radiographic and three-dimensional model features and review of the literature.

No association between types of unilateral mandibular condylar abnormalities and facial asymmetry in orthopedic-treated patients with juvenile idiopathic arthritis.

INTRODUCTION: Dentofacial asymmetries are often observed in patients with juvenile idiopathic arthritis (JIA) and temporomandibular joint (TMJ) involvements. The aim of this split-face study was to associate types of radiologic TMJ abnormalities with the degree of dentofacial asymmetry in patients with unilateral TMJ involvements assessed with cone-beam computed tomography. METHODS: Forty-seven JIA patients and 19 nonarthritic control subjects were included in the study. Normal condylar radiologic cone-beam computed tomography appearance in at least 1 TMJ was the inclusion criterion for all patients with JIA. The contralateral TMJ was thereafter scored as either "normal," "deformed," or "erosive," consistent with predefined criteria. Based on the bilateral radiologic TMJ appearances, 3 JIA groups were assigned: normal/normal, normal/deformed, and normal/erosive. The severity of the dentofacial asymmetry was compared between the JIA groups and control subjects. Dentofacial asymmetry was expressed as interside ratios and angular measurements. RESULTS: Eighty-seven percent of the JIA patients were being treated or had previously received treatment with a functional orthopedic appliance at the time of the cone-beam computed tomography. Significantly greater dentofacial asymmetries were observed in the 2 groups of JIA patients with unilateral condylar abnormalities (deformation or erosion) than in the other groups. A similar degree of dentofacial asymmetry was observed in JIA patients with bilateral normal TMJs and in the nonarthritic control group. CONCLUSIONS: JIA patients with unilateral condylar abnormalities (deformation or erosion) exhibited significantly more severe dentofacial asymmetries than did the JIA patients without condylar abnormalities and the control subjects. We found the same degree of dentofacial asymmetry when dividing patients with condylar abnormalities into deformation and erosion groups.

Mandibular condylar hypoplasia in children with isolated unilateral congenital aural atresia.

OBJECTIVES/HYPOTHESIS: We hypothesized that children with isolated nonsyndromic unilateral congenital aural atresia have subclinical mandibular condylar hypoplasia ipsilateral to the atretic ear, and that the Jahrsdoerfer score is associated with the degree of condylar hypoplasia. STUDY DESIGN: Retrospective self-controlled case series. METHODS: We reviewed high-resolution computed tomography scans of the temporal bones of 68 children with isolated nonsyndromic unilateral congenital aural atresia. Images were viewed in the transverse (axial) plane perpendicular to the axis of the mandibular ramus and scanned from the mandibular notch to the condylar top. The slice where the condyle had the largest cross-sectional area was measured and checked for correlation with atresia status, age, and sex. The Jahrsdoerfer score of the atretic ear was calculated and correlated with condyle cross-sectional area, age, and sex. RESULTS: Cross-sectional area of the condyle ipsilateral to the atretic ear was, on average, 8.41 mm2 smaller than the contralateral condyle (P < .0001). The Jahrsdoerfer score was not associated with the condylar cross-sectional area, age, or sex. CONCLUSION: Isolated nonsyndromic unilateral congenital aural atresia is associated with mild hypoplasia of the mandibular condyle ipsilateral to the atretic ear. This is consistent with the hypothesis that congenital aural atresia is a variant of craniofacial (hemifacial) microsomia. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:1191-1195, 2018.

Congenital Abnormalities of the Temporomandibular Joint.

Congenital deformities of the temporomandibular joint (TMJ) complex can present as a heterogeneous continuum of growth disturbances of the mandibular condyle, articular eminence, and temporal bone. This article describes several syndromes with congenital condylar deformity, including mandibulofacial dysostosis (Treacher Collins syndrome), hemifacial microsomia, oculoauriculovertebral syndrome, oculomandibulodyscephaly (Hallermann-Streiff syndrome), and Nager syndrome. Variations in the extent of TMJ deficiency seen in each individual case influence the timing and techniques of TMJ reconstruction.

SPECT bone scintigraphy for the assessment of condylar growth activity in mandibular asymmetry: is it accurate?

The comparison of serial radiographs and clinical photographs is considered the current accepted standard for the diagnosis of active condylar hyperplasia in patients with facial asymmetry. Single photon emission computed tomography (SPECT) has recently been proposed as an alternative method. SPECT can be interpreted using three reported methods absolute difference in uptake, uptake ratio, and relative uptake. SPECT findings were compared to those from serial comparisons of radiographs and clinical photographs taken at the time of SPECT and a year later; the sensitivities and specificities were determined. Two hundred patient scans were evaluated. Thirty-four patients showed active growth on serial growth assessment. On comparison with serial growth assessment, the sensitivity and specificity of the three methods ranged between 32.4% and 67.6%, and 36.1% and 78.3%, respectively. Analysis using receiver operating characteristic (ROC) curves revealed area under the curve (AUC) values of <0.58. The average age (mean±standard deviation) of patients with active growth was 18.6±2.8 years, and average growth in the anteroposterior, vertical, and transverse directions was 0.94±0.91mm, 0.88±0.86mm, and 1.4±0.66 mm, respectively. With such low sensitivity and specificity values, it is not justifiable to use SPECT in place of serial growth assessment for the determination of condylar growth status.

CT Findings of Trifid Mandibular Condyle in a 12Year-Old Patient: A Case Report and Review / Hallazgos en TC de Cóndilo Mandibular Trífido en un Paciente de 12 Años: Reporte de Caso y Revisión

ABSTRACT: Bifid or trifid mandibular condyle is an extremely rare entity, of unknown etiology, although it has been associated with trauma in the condyle growth center. The development of imagining techniques has allowed the exact characterization of these alterations, which were incidentally discovered by routine dental x-rays. The aim of this report is to describe a case of a mandibular condyle with a trifid appearance in a twelve year-old individual with a history of mandibular trauma during childhood and a review of the relevant literature.

RESUMEN: El cóndilo bífido o trífido es una entidad extremamente rara de etología desconocida, sin embargo, ha sido asociada con trauma en el centro de crecimiento condilar. El desarrollo de técnicas imagenológicas ha permitido la exacta caracterización de estas alteraciones, las cuales son incidentalmente descubiertas durante radiografías de rutina. El objetivo de este reporte es describir un caso de un cóndilo mandibular con apariencia trífida en un paciente de 12 años de edad con historia de trauma en la mandíbula durante la primera infancia y una revisión de la literatura relevante.

Cóndilo mandibular bífido bilateral / Bilateral bifid mandibular condyle

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Three-dimensional analysis of mandibular condyle position in patients with deviated mandibular prognathism.

The purpose of this study was to evaluate the bilateral difference in condyle position in patients with deviated mandibular prognathism. Patients with asymmetrical (n=28) and symmetrical mandibular prognathism (n=23) were compared using the three-dimensional (3D) reformatted image from cone beam computed tomography. Significant positional differences in the condyle and subcondyle region (sigmoid notch) were found between the deviated and contralateral sides in the group with asymmetrical mandibular prognathism, but not in the control group. The lateral condyle was more laterally and inferiorly positioned on the contralateral side than on the deviated side (P<0.05). The sigmoid notch was more laterally, superiorly, and posteriorly positioned on the deviated side (P<0.01). Interestingly, condyle width and height on the deviated side was narrower and shorter than on the contralateral side and in the control group. Menton deviation was closely correlated with the bilateral difference in condyle height and 3D position of the sigmoid notch (P<0.01). The degree of asymmetry was more highly correlated with condyle height than with the spatial orientation of the condyle head. The results demonstrated that mandibular prognathism with asymmetry is associated with bilateral differences in 3D morphology and orientation of the condyle. Therefore, clinicians should consider these variations during surgical planning.

Sequential changes of postoperative condylar position in patients with facial asymmetry.

OBJECTIVE: To evaluate sequential images of the condylar position in relation to the glenoid fossa after orthognathic surgery in patients with facial asymmetry using cone beam computed tomography. MATERIALS AND METHODS: A total of 20 adult patients (11 men and 9 women; mean age, 22.1 ± 4.02 years) with facial asymmetry who underwent sagittal split ramus osteotomy with rigid fixation were involved. Cone beam computed tomography scans were obtained before treatment (T0), 1 month before the surgery (T1), and 1 day (T2), 3 months (T3), 6 months (T4), and 12 months (T5) after the surgery. The condyle position was evaluated. RESULTS: At 1 day after surgery (T2), the condylar position on both sides significantly changed posteriorly, inferiorly, and laterally, but no significant difference was observed between the nonaffected and affected sides. The condyle on the nonaffected side had a tendency to recover its preoperative position at 3 months after surgery (T3) and inclined slightly laterally up to 1 year after the surgery (T5). The condyle on the affected side returned more closely to the glenoid fossa than to its pretreatment position at 3 months after surgery (T3). Thereafter, it showed a more backward and downward position (T5). CONCLUSIONS: The overall condylar position after an orthognathic surgery in patients with facial asymmetry was relatively stable at 1 year after surgery. However, the condyle on the affected side during the first 3 months after surgery should be carefully monitored for surgical stability.

Incidence of a Bifid Mandibular Condyle in Dry Mandibles.

BACKGROUND: A bifid mandibular condyle (BMC) is a rare anatomical variation with an etiology not fully understood. Although there are numerous case reports regarding it, purposeful epidemiological investigations on the BMC frequency among different groups are scarce. This study aims to investigate the incidence and laterality of BMC among series of adult males from Bulgaria and perform a morphometric analysis of it. MATERIALS AND METHODS: A series of 500 dry intact mandibles from adult males was investigated. The condyles were macroscopically observed and when skulls were available, the corresponding mandibular fossae were also inspected. In the cases when bifid condyles were found, 27 measurements were taken. RESULTS: Bifid mandibular condyle was observed in 4 (0.8%) mandibles. All of the cases were unilateral, 2 on the right side (0.4%) and 2 on the left (0.4%). The condyles were divided into medial and lateral heads by a sagittal fissure or a notch. CONCLUSION: The established frequency of BMC was comparable with those reported in Turkish and Korean populations. The lack of injury marks and traces implies a developmental etiology of this condition.