Three-dimensional computed tomography evaluation of postsurgical condylar displacement after mandibular osteotomy.
OBJECTIVE
The purpose of this study was to examine both condylar displacement of the temporomandibular joint after sagittal split ramus osteotomy with rigid osteosynthesis and intraoral vertical ramus osteotomy without osteosynthesis in patients with mandibular prognathism by means of three-dimensional computed tomography.


METHODS
In this pilot study, five patients treated with sagittal split ramus osteotomy and 5 patients treated with intraoral vertical ramus osteotomy were evaluated. A technique to superimpose a postoperative three-dimensional computed tomography image on its corresponding preoperative image was designed. Postoperative condylar displacement, rotation, and tilting were measured in three-dimensional computed tomography images.


RESULTS
Within 3 to 6 months after surgery, changes in the inclination of the condylar axes were distinctly seen, although changes in the position of the condyles within the joints were minimal. In particular, outward rotation of the condylar long axes after intraoral vertical ramus osteotomy was a frequent finding.


CONCLUSIONS
The three-dimensional computed tomography superimposition technique was a practical method of evaluating postsurgical condylar displacement after mandibular osteotomy.
Kawamata
A
A
Department of Oral Radiology, Asahi University School of Dentistry, Gifu, Japan.
Fujishita
M
M
Nagahara
K
K
Kanematu
N
N
Niwa
K
K
Langlais
R P
RP
D000293:Adolescent; D000328:Adult; D001860:Bone Plates; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D008335:Mandibular Condyle / Q000000981:diagnostic imaging* / Q000601:surgery; D009068:Movement; D009971:Orthodontics, Corrective; D010027:Osteotomy / Q000379:methods*; D010865:Pilot Projects; D011378:Prognathism / Q000601:surgery; D012399:Rotation; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*