Observation of the temporal crest canal in the mandibular ramus by cone beam computed tomography and macroscopic study.
OBJECTIVE
The mandibular ramus is regarded as a relatively safe zone for a sagittal splitting osteotomy or for harvesting bone during implant treatment. The only important anatomical structure is the mandibular canal. The mandible has some anatomical variants that need to be recognized, such as a bifid mandibular canal, a retromolar canal, and rarely a temporal crest canal (TCC). In this study, cadaver mandibles were used to evaluate the TCC in the mandibular ramus using cone beam computed tomography (CBCT).


METHODS
Altogether, 90 sites on 48 mandibles from Japanese cadavers were examined in this study. The CBCT volumetric images were acquired for areas of 79 mm[Formula: see text] 71 mm. Three-dimensional observation of the images was undertaken to estimate the frequency, position of the orifices, and canal continuity. The cadaver mandibles in which the TCCs were observed were dissected from the inner surface to confirm the contents.


RESULTS
Five TCCs (5.6 %) were observed in 90 observation areas. At least one TCC was confirmed in four (8.3 %) of 48 mandibles. Two types of TCC were recognized. Dissection revealed that they contained neurovascular bundles.


CONCLUSIONS
Three-dimensional diagnosis is essential prior to surgical procedures in the mandibular ramus because unexpected blood vessels may be present that may cause bleeding or complications during the surgery.
Department of Oral and Maxillofacial Radiology, School of Life Dentistry at Tokyo, Nippon Dental University, 1-9-20, Fujimi Chiyoda-ku, Tokyo, 102-8159, Japan, t-kawai@tky.ndu.ac.jp.
Taisuke
T
Kawai
Rieko
R
Asaumi
Yasuo
Y
Kumazawa
Iwao
I
Sato
Takashi
T
Yosue
D002102:Cadaver; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging* / Q000601:surgery; D010027:Osteotomy; D015203:Reproducibility of Results