Morphological analysis of lingula shape in a modern Italian cemeterial population: Clinical and forensic considerations

The lingula is a small bony projection emerging from the medial ridge of the mandibular foramen, subjected to morphological variations. To date, scientific literature has described four different shapes (truncated, triangular, nodular and assimilated) and the relative distributions in different human populations. However, no data are available on Europeans so far. To this purpose, the present study aims to evaluate the distribution of the lingula shapes in the Italian population and to verify its relevance in ancestry estimation. Lingula was analysed in 235 dry mandibles selected among contemporary Italian cemeterial skeletons. Since only well-preserved sides were considered, 453 sides were evaluated according to a classification method, which includes the description of a fifth shape (the bridge shape) and the presence of mixed morphologies. In our sample, the most prevalent shape was the truncated shape (38.6%), followed by the nodular (26.3%), mixed morphologies (15.2%), triangular (10.8%), bridge (5.1%) and assimilated (4.0%) shapes. Within mixed morphologies, the most prevalent were the nodular/truncated (31.9%), nodular/triangular (30.4%), and nodular/assimilated (23.2%). Differently to previous studies, the lingula morphology could not actually offer a concrete and reliable help to ancestry estimation. However, its shape and extension would assume a stronger clinical influence for the execution and success of the alveolar nerve block used in dental and maxillofacial surgery procedures.