Observation of the anterior loop and mental foramen of the mandibular canal using cone beam computed tomography

Koh, Kwang Joon; Kim, Kyoung A

Abstract

PURPOSE : To evaluate the anteroposterior length and buccal angle of the anterior loop, and the size and location of the mental foramen using cone beam computed tomography (CBCT).
MATERIALS AND METHODS
: 100 CBCT images from 87 adults (43 males and 44 females) ranging in age from 20 to 73 years (average 50 years) with edentulous ridge of the mandibular premolar region were obtained. Axial, sagittal, coronal images were reconstructed from Dental and Block Images of CBCT. The anteroposterior length, shape and buccal angle of the anterior loop, and the size and location of the mental foramen were calculated from reconstructed images of axial, sagittal and coronal CBCT.
RESULTS
: The anteroposterior length and buccal angle of the mental canal was 4.0+/-1.2 mm, 37.8+/-11.6 degrees respectively. The loop type with straight course was the most common shape of the mental canal. The location of the mental foramen below the apex of the lower second premolar (78%) was the most common. The maximum size of the mental foramen was 4.6+/-1.0 mm in width and 3.0+/-0.6 mm in height. The inner size of the mental canal was 2.6+/-0.6 mm in width and 2.1mm+/-0.4 mm in height.
CONCLUSION
: CBCT is useful to evaluate the anterior loop and mental foramen of the mandibular canal. Safe guideline of 4 mm from the most anterior point of the mental foramen is recommended for implant and surgical treatment.