Assessment of pterygomaxillary separation in Le Fort I Osteotomy in class III patients.
OBJECTIVE
To examine the separation of the pterygomaxillary region at the posterior nasal spine level after Le Fort I osteotomy in Class III patients.


METHODS
The study group consisted of 37 Japanese patients with mandibular prognathism and asymmetry, with maxillary retrognathism or asymmetry. A total of 74 sides were examined. Le Fort I osteotomy was performed without a pterygoid osteotome, with an ultrasonic curette used to remove interference at the pterygomaxillary region. Postoperative computed tomography (CT) was analyzed for all patients. The separation of the pterygomaxillary region and the location of the descending palatine artery were assessed.


RESULTS
Although acceptable separation between the maxilla and pterygoid plates was achieved in all patients, an exact separation of the pterygomaxillary junction at the posterior nasal spine level was found in only 18 of 74 sides (24%). In 29 of 74 sides (39.2%), the separation occurred anterior to the descending palatine artery. In 29 of 74 sides (39.2%), complete separation between the maxilla and lateral and/or medial pterygoid plate was not achieved, but lower level separation of the maxilla and pterygoid plate was always complete. The maxillary segments could be moved to the postoperative ideal position in all cases.


CONCLUSIONS
Le Fort I osteotomy without an osteotome does not always induce an exact separation at the pterygomaxillary junction at the posterior nasal spine level, but the ultrasonic bone curette can remove the interference between maxillary segment and pterygoid plates more safely.
Ueki
Koichiro
K
Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, Kanazawa, Japan. kueki@med.kanazawa-u.ac.jp
Hashiba
Yukari
Y
Marukawa
Kohei
K
Okabe
Katsuhiko
K
Alam
Shamiul
S
Nakagawa
Kiyomasa
K
Yamamoto
Etsuhide
E
D000293:Adolescent; D000328:Adult; D001158:Arteries; D001860:Bone Plates; D001863:Bone Screws; D002508:Cephalometry / Q000379:methods; D003475:Curettage / Q000295:instrumentation; D005146:Facial Asymmetry / Q000601:surgery; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008313:Malocclusion, Angle Class III / Q000601:surgery*; D008437:Maxilla / Q000002:abnormalities / Q000601:surgery*; D008443:Maxillary Sinus / Q000601:surgery; D008875:Middle Aged; D009295:Nasal Bone / Q000601:surgery; D019340:Osteotomy, Le Fort / Q000295:instrumentation / Q000379:methods*; D010159:Palate / Q000098:blood supply / Q000601:surgery; D011378:Prognathism / Q000601:surgery; D013100:Sphenoid Bone / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D014464:Ultrasonic Therapy / Q000295:instrumentation; D055815:Young Adult