Positional change in mandibular condyle in facial asymmetric patients after orthognathic surgery: cone-beam computed tomography study

Abstract

BackgroundWe evaluated change in the mandibular condyle after orthognathic surgery using cone-beam computed tomography (CBCT) in patients with facial asymmetry.MethodsThirty patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry were classified into two groups according to the amount of menton deviation (MD) from the facial midline on anteroposterior (AP) cephalogram: group A (asymmetry, MD ≥ 4 mm; n = 15) and group B (symmetry, MD < 4 mm; n = 15). Position and angle of condylar heads on the axial, sagittal, and coronal views were measured within 1 month preoperatively (T0) and postoperatively (T1) and 6 months (T2) postoperatively.ResultsOn axial view, both groups showed inward rotation of condylar heads at T1, but at T2, the change was gradually removed and the condylar head returned to its original position. At T1, both groups showed no AP condylar head changes on sagittal view, although downward movement of the condylar heads occurred. Then, at T2, the condylar heads tended to return to their original position. The change in distance between the two condylar heads showed that they had moved outward in both groups, causing an increase in the width between the two heads postoperatively. Analysis of all three-dimensional changes of the condylar head positions demonstrated statistically significant changes in the three different CBCT views in group B and no statistically significant changes in group A.ConclusionsThere was no significant difference between the two groups in condylar head position. Because sagittal split ramus osteotomy can be performed without significant change in symmetrical and asymmetrical cases, it can be regarded as an effective method to stabilize the condylar head position in patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry.

Evaluation of Condylar Positional, Structural, and Volumetric Status in Class III Orthognathic Surgery Patients

“…The proportions of anteriorly positioned condyles decreased only minimally. This finding is in accordance with the previous research of Kim et al [43,44], Iguchi et al [45], and Choi et al [46,47]. In the maxillary single-jaw surgery group, the condyles were positioned anteriorly or concentrically before the surgery.…”

“…The available evidence regarding angular rotation in the axial plane is controversial. Several studies [46,47,49,50] found that condyles tend to rotate inwards immediately after surgery. However, longer-term follow-ups showed that condyles tend to regress to their original position.…”

Evaluación de la posición condilar mediante tomografía computarizada de haz cónico en pacientes Clase III sometidos a cirugía ortognática

“…Byung-Joon Choi y cols. 23 , en su estudio, reportan que no se encuentran cambios significativos en la evaluación de la posición condilar. En nuestra experiencia no se encontraron cambios significativos entre la medición condilar inicial y la medición final.…”

Short-term and long-term alterations of condylar position after bilateral sagittal split ramus osteotomy for mandibular setback: A preliminary before-after clinical trial

“…[ 2 ] One of the most common methods in the management of excessive mandibular prognathism is mandibular setback using bilateral sagittal split ramus osteotomy (BSSRO), which has many advantages including a wide contact area between segments facilitating healing as well as convenient relocation of the distal segment; it also has certain complications including condylar displacement and a rather high rate of relapse. [ 1 2 3 4 5 ] In BSSRO, the mandible is divided into distal and proximal segments to enable their displacement. [ 4 6 ] In such cases, it is of significant value to maintain the initial positions of the condylar heads.…”

“…[ 1 2 3 4 5 ] In BSSRO, the mandible is divided into distal and proximal segments to enable their displacement. [ 4 6 ] In such cases, it is of significant value to maintain the initial positions of the condylar heads. [ 4 6 ] because it can help prevent post-BSSRO relapse.…”