Mandibular and temporomandibular morphologic characteristics of patients with suspected unilateral condylar hyperplasia: a CT study

Abstract

Introduction: Facial asymmetry associated with unilateral condylar hyperplasia (UCH) is a complicated clinical condition. Objective: The objective of this study was to describe morphological characteristics of the mandible and the temporomandibular joint in patients with facial asymmetry, using computed tomography and 3D reconstruction. Methods: A retrospective observational study was performed with patients displaying facial asymmetry evaluated by single photon emission computed tomography (SPECT)/CT analysis, for suspected UCH, between 2015 and 2018. The following variables were compared between the affected side (producing the asymmetry) and the contralateral side (side to where the jaw is deflected): condylar length, condylar medial and lateral pole length, mandibular ramus length, intra-articular spaces, articular eminence height and position of the posterior wall of the glenoid fossa. Results: Forty-three patients (21 women, mean age: 20.7 ± 7.25 years) with facial asymmetry were included, 19 patients presented right side deviation and 24 patients had left side deviation. Condylar length, lateral pole length, the sum of maximum values and articular eminence height were greater in the affected side (p< 0.05). A positive correlation was found between the position of the posterior wall of the glenoid fossa and the articular eminence height in the affected side (r = 0.442). Conclusions: In patients with suspected UCH, evaluated through CT, craniofacial measurements showed significantly larger condylar length and the condylar sum of maximum values in the affected side. A positive correlation was found between the increased dimensions of the articular eminence and the more posterior position of the glenoid fossa in the affected side.

Case Report: unilateral condylar hyperplasia

“…CT imaging aids in multiplanar imaging of the condyles 22 . A recently conducted retrospective CT based study revealed a significant increase in condylar length and other dimensions on the hyperplastic side when compared to the normal side 23 . CH characteristically appears as a uniform enlargement of the condylar head 19 , 24 .…”

Positional Features of the Mandibular Condyle in Patients with Facial Asymmetry

“…Likewise, in the present study, when the values are analyzed by affected side and by each entity, with the exception of GFA, all joint spaces were smaller. It was even evident in cases of condylar hyperplasia, in which there is a substantial change in the condylar size and the height of the joint cavity towards the affected side [ 31 ]. It was evidenced that the joint spaces were decreased with respect to the non-asymmetric subjects and only for the posterior joint space it was not significant in HH.…”

Unilateral condylar hyperplasia treated with simultaneous 2-jaw orthognathic surgery and posterior segmental osteotomy

“…8,9 CH can be broadly classified into three types: hemimandibular hyperplasia, in which the vertical lengths of the mandibular condyle and ramus increase; hemimandibular elongation, in which the horizontal lengths of the mandibular condyle and ramus increase; or a hybrid form. [9][10][11] In the hybrid form, there is a combination of the 2 vectors, with a resultant severe expression of the pathology. If the unilateral mandibular condyle increases in length vertically, canting-type facial asymmetry occurs.…”