Morphologic and Morphometric Analysis of Lingula in Localizing Mandibular Foramen with its Surgical Importance

Abstract

Introduction: Morphologic and morphometric evaluation of mandible is clinically important. Considering the close relationship of lingula with neurovascular structures entering through mandibular foramen, lingula is often used as an important bony landmark during oral and maxillofacial surgical approach and inferior alveolar nerve block anaesthesia. Inadequate anatomical knowledge may result various intra operative complications like haemorrhge, fractures and nerve injury. Also, structural variations of lingula followed by inaccurate localization of mandibular foramen have been implicated as causative factor for unsuccessful inferior alveolar nerve block anaesthesia. Aim: To determine morphological and morphometric variations related to lingula of mandible in localizing mandibular foramen and to compare the results with similar type of osteological studies performed earlier on different population group. Materials and Methods: The study was performed on 36 adult dry human mandibles on both sides to categorize lingula according to its various shapes and determine the location of lingula based on surrounding mandibular landmarks by using Vernier caliper as 5 distances from tip of lingula as follows: i) to anterior border of ramus of mandible; ii) to posterior border of ramus of mandible; iii) to centre of mandibular notch; iv) to the alveolar socket of second molar tooth; and v) to the base of mandible. The present study also indicated bilingual distance between tips of lingula of both sides. Data collected were analyzed statistically. Results: The most common shape of lingula was observed as triangular (51.39%) followed by truncated (23.61%), then nodular (20.83%) and assimilated (4.17%) as least prevalent type. The average distances of tip of lingula from anterior and posterior borders of ramus of mandible were 18.21±1.50 mm and 16.33±1.21 mm respectively. On average, the tip of lingula was situated at 18.17±1.51 mm, 33.40±2.11 mm and 32.07±2.68 mm from mandibular notch, second molar tooth and base of the mandible respectively. The average bilingual distance between lingula of both sides was observed as 73.35±3.94 mm. Conclusion: Considering morphologic and morphometric variations of lingula as of great clinical importance in the field of surgery involving mandibular ramus, present study may be helpful by adding important information about localization of mandibular foramen with respect to variations of lingula.

Keywords

• Inferior alveolar nerve
• Mandible
• Maxillo-facial surgery