Imaging study on relationship between the location of lingula and the Gonial angle in a Chinese population

Purpose The purpose of this study was to investigate the Gonial angle in relation to the position of the lingula using computerized image analysis to guide the oral surgeons to prevent injury to the inferior alveolar nerve and peripheral blood vessels during surgery. Methods We measured Gonial angle sizes of bilateral rami and the distances from the lingula tip to the mandibular notch (LN), the anterior (LA) and posterior (LP) margin of the mandibular ramus, the mandibular base (LB) and the occlusive plane ( h ) in 407 Chinese adults with CBCT. Results In males, the mean distance of LN was 17.64 mm in the low Gonial angle group while 16.76 mm in the high Gonial angle group, which was significantly different between two groups ( P < 0.001). The distance of LA in LGA group was obviously longer than that in HGA group ( P < 0.001). The mean distance LP of men was 17.94 mm in LGA group while 16.9 mm in HGA group ( P < 0.001). In females, the mean distance of LB in LGA group was 33.32 mm and 32.37 mm in HGA group ( P < 0.01). Conclusion We discovered that the segment of the mandibular branch, between the mandibular lingula and the mandibular angle, was obviously smaller in the HGA group than that in the LGA group.