Assessment of the Anterior Loop of the Mental Nerve Using Cone Beam Computerized Tomography Scan

Abstract

The purpose of this study is to use cone-beam computerized tomography (CBCT) scans with oblique-transverse reconstruction modality to measure and compare the anterior loop length (AnLL) of the mental nerve between gender and age groups and to compare the difference between the right and left sides. Sixty-one female and 61 male CBCT scans were randomly selected for each age group: 21-40, 41-60, and 61-80 years. Both right- and left-side AnLLs were measured in each subject using i-CATVision software to measure AnLLs on the oblique transverse plane using multiplanar reconstruction. The anterior loop was identified in 85.2% of cases, with the mean AnLL of the 366 subjects (732 hemimandibles) being 1.46 ± 1.25 mm with no statistically significant difference between right and left sides or between different gender groups. However, the mean AnLL in the 21-40 year group (1.89 ± 1.35 mm) was larger than the AnLL in the 41-60 year group (1.35 ± 1.19 mm) and the 61-80 year group (1.13 ± 1.08 mm). In conclusion, when placing implants in close proximity to mental foramina, caution is recommended to avoid injury to the inferior alveolar nerve. No fixed distance anteriorly from the mental foramen should be considered safe. Using CBCT scans with the oblique-transverse method to accurately identify and measure the AnLL is of utmost importance in avoiding and protecting its integrity.

Prevalence and measurement of anterior loop of the mandibular canal using CBCT: A cross sectional study

“…Mental nerve loop is present in 11.76% of our study population which correlates approximately with 7% as studied by Jacobs et al in the wide range of its prevalence percentage ranging from 7% to 82% …”

Characteristics of intrabony nerve canals in mandibular interforaminal region by using cone‐beam computed tomography and a recommendation of safe zone for implant and bone harvesting

“…Previous studies have shown that the prevalence of the AL varied widely from 48% to 96.25%. In the cadaver studies, the prevalence were from 88% to 96.25%, which were higher than the studies based on CBCT (48%‐85.2%) . The reason of lower detection in CBCT was that the canal is too thin to be observed.…”

“…In the cadaver studies, the prevalence were from 88% to 96.25%, [20][21][22] which were higher than the studies based on CBCT (48%-85.2%). 12,13,23 The reason of lower detection in CBCT was that the canal is too thin to be observed. Therefore, no detection of intrabony nerve canals in CBCT does not mean that it could be ignored.…”

“…In CBCT studies, the prevalence of the AL varied widely from 48% to 85.2% and the prevalence of the MIC varied from 83% to 100% . The influence of ethnic background might cause these differences.…”

“…In recent years, CBCT is widely used to derive clinical recommendations for preoperative planning to reduce the complications in implant surgeries. 11 In CBCT studies, the prevalence of the AL varied widely from 48% to 85.2% 12,13 and the prevalence of the MIC varied from 83% to 100%. 14,15 The influence of ethnic background might cause these differences.…”