Association between condylar morphology and mandibular asymmetry. Cases report

The mandibular asymmetry is defned when there is an unbalanced regarding to the homologous parts composing to the mandible complex affecting the proportions among the structures.This condition is relatively common, with a prevalence of 21% to 85%.The etiology of mandibular asymmetries is multifactorial, including genetic, environmental and congenital influences. Temporomandibular joint (TMJ) structural abnormalities are important etiologic factors that may lead to mandibular growth disturbances. Some alterations of condylar morphology can lead to the development of mandibular asymmetry: Bifid or trifid mandibular condyles are extremely rare entities, of unknown etiology, although they have been associated with trauma involving the temporo mandibular joint (TMJ). Although there are cases supportingthis hypothesis, bifd condyle has also been reported in patients with no known history of trauma; Condylar Hyperplasia is a disorder characterized by an excessive bone growth of the mandibular condyle which brings a number of facial, occlusal and functional alterations that may also interfere with the patient’s psychosocial development; Condylar hypoplasia is a bone disease characterized by the decreased development of one or both the mandibular condyles. All these alterations of condylar growth lead to the development of mandibular asymmetries that are usually asymptomatic. The objective of this report is to describe three cases of mandibular asymmetry associated with trifd condyle, condylar hyperplasia, bifid condyle and condylar hypoplasia, which were attended by the Orthodontic Department in the Faculty of Dentistry of the University Central of Venezuela. Cases Report: 1- Male patient of 12 years of age, asymptomatic, with a history of facial trauma at 3 years of age. An extra-oral examination revealed a slight mandibular deviation towards the left side. Skeletal and dental Class II patient with deep bite was present.The articular clinical evaluation presented normal-mobility in opening and closing and in excursion movements, as well as the absence of joint noises. The evaluation of Computed Tomography (CT) shows a trifd condyle on the left side. 2- Male patient of 15 years of age, with antecedent trauma at the chin at 4 years of age. Extra-oral examination revealed gross facial asymmetry of the lower third of the face with deviation of the mandible to the left side. Patient showed a skeletal and dental Class I, deep bite and canting the occlusal plane. There was evident reciprocal clicking of the left TMJ and pain associated on palpation of the left TMJ. CT revealed condylar hyperplasia in the right TMJ. MRI showed disc displacement with reduction in left TMJ and disc thinned in right TMJ. 3- Female patient, asymptomatic, 21 years old with severe mandibular asymmetry with deviation on the right side. Skeletal Class III and dental Class I right and left Class III with canting of the occlusal plane. The TMJ evaluation revealed bilateral noises. CT showed a bifd condyle on the left side and condylar hypoplasia on the right side. In MRI, bilateral disc displacement was observed. Conclusions: The relationship between TMJ morphology and facial skeletal deformities was reported from many authors. These cases suggested that mandibular asymmetry was associated with condylar morphology. Understanding the etiology of mandibular asymmetry is extremely important in the management of patients. Early diagnosis of this condition is the key for satisfactory results in such patients.