Comprehending the three-dimensional mandibular morphology of facial asymmetry patients with mandibular prognathism

Abstract

BackgroundThe purpose of this study was to elucidate the factors that cause facial asymmetry by comparing the characteristics of the mandibular morphology in patients with mandibular prognathism with or without facial asymmetry using three-dimensional computed tomography (3D-CT).MethodsWe studied 28 mandibular prognathism patients whose menton deviated by ≥ 4 mm from the midline (FA group, n = 14) and those with a < 4-mm deviation (NA group, n = 14). DICOM data from multislice CT images were reconstructed and analysed using 3D image analysing software. Mandibular structures were assessed via linear, angular, or volumetric measurements and analysed statistically.ResultsThe lengths of the ramal and body components and condylar volume in the FA group were significantly greater on the nondeviated side than those on the deviated side. The mandibular body length of the nondeviated side in the FA group was significantly longer than that of the NA group. Other components of the FA group did not significantly differ from those of the NA group.ConclusionsImbalances in the sizes of the ramal and body components as well as the increased body length of the nondeviated side in the FA group compared with that of the NA group may contribute to facial asymmetry in patients with mandibular prognathism.

Facial asymmetry assessment in skeletal Class III patients with spatially-dense geometric morphometrics

“…In this study, the chin was identified as the most asymmetric region and with relatively large individual variation among skeletal Class III patients, which is consistent with previous findings (1,16). This most likely results from positional displacement or morphological alteration of the mandible (17,22). Pronounced asymmetry has also been detected in the cheek and nose, which have been rarely investigated in related literature.…”

Three-Dimensional Analysis of the Condylar Hypoplasia and Facial Asymmetry in Craniofacial Microsomia Using Cone-Beam Computed Tomography

“…[24][25][26][27] Second, as the condylar hypoplasia on the CFM-affected side increased, the facial asymmetry toward the ipsilateral side increased; coincidently in the non-syndromic studies, the smaller condyle of the chin-deviated side compared to that of the non-deviated side 28 was associated with a more severe chin deviation. 21,22 Finally, the CFM cases commonly showed chin deviation along with corresponding maxillomandibular cant toward the CFM-affected side regardless of the Pruzansky-Kaban types. The menton deviation in CFM was found to be significantly correlated with the canting of the occlusal plane (r = 0.905, P < .001) and mandibular plane (r = 0.691, P < .001).…”

“…In the current CFM study, there were comparable patterns of facial asymmetry and condylar asymmetry to those reported in other studies on non-syndromic facial asymmetry with various malocclusion (Class I, II and III), although the extents of asymmetry in CFM were unsurprisingly greater. [21][22][23] First, the CFM subjects showed increased severity of asymmetry for the lower part of face (Table 5). [24][25][26][27] Second, as the condylar hypoplasia on the CFM-affected side increased, the facial asymmetry toward the ipsilateral side increased; coincidently in the non-syndromic studies, the smaller condyle of the chin-deviated side compared to that of the non-deviated side 28 was associated with a more severe chin deviation.…”

Diferencias en la morfología ósea entre el lado desplazado y contralateral en pacientes con asimetría facial: Estudio 3D-TC

“…También es importante mencionar que la longitud del cuerpo mandibular fue mayor para el lado contralateral, coincidiendo con lo encontrado por Kamata y Col. (23). Este hallazgo difiere de lo que se puede esperar: una mayor longitud en el lado desplazado, que es el que produce la asimetría.…”