Trigeminal nerve hypesthesia after sagittal split osteotomy in setback cases: correlation of postoperative computed tomography and long-term trigeminal somatosensory evoked potentials.
OBJECTIVE
We sought to assess the relationship of the inferior alveolar nerve to the osteotomy site after bilateral sagittal split osteotomy (BSSO) and to correlate the nerve osteotomy relationship as the cause of long-term postoperative hypesthesia.


METHODS
The subjects consisted of 28 patients with mandibular prognathism who underwent BSSO setback surgery. The distance between the ostectomized surface of the mandibular ramus and mandibular canal was measured and scored on a computed tomograph (CT). The relationship between this distance and the presence and degree or absence of trigeminal nerve hypesthesia was objectively evaluated by latency delay of the trigeminal somatosensory evoked potential (TSEP) records.


RESULTS
Five of the 56 sides (8.9%) showed latency delays more than 1 year after the operations. Scored CT points between the canal and the split surface strongly correlated with TSEP latency recovery (Y = 1.716X + 41.2).


CONCLUSIONS
This relationship between the canal and the osteotomy site is related to long-term hypesthesia in BSSO postoperatively.
Nakagawa
Kiyomasa
K
Department of Oral and Macillofacial Surgery, Graduate School of Medicine, Kanazawa University, Kanazawa, Japan. nakagawa@med.kanazawa-u.ac.jp
Ueki
Koichiro
K
Takatsuka
Shigeyuki
S
Yamamoto
Etsuhide
E
D000293:Adolescent; D000328:Adult; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005260:Female; D006801:Humans; D006987:Hypesthesia / Q000209:etiology*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D008340:Mandibular Nerve / Q000000981:diagnostic imaging; D008875:Middle Aged; D010027:Osteotomy / Q000009:adverse effects* / Q000379:methods; D011378:Prognathism / Q000601:surgery; D011930:Reaction Time / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D014057:Tomography, X-Ray Computed; D014276:Trigeminal Nerve / Q000503:physiopathology*; D020433:Trigeminal Nerve Diseases / Q000209:etiology*