Morphometric Analysis of Retromolar Triangle in Eastern Indian Population

Abstract

Background: Retromolar triangle exhibits great variation related with the 3rd molar presence, their impactation grade, its loss. RMT bone can be used as autological graft. RMT presents foramina of variable number and dimension. RMF of variable diameter can be found in different regional populations. Present study explores a morphometric study of RMT and their relationship to the mandibular canal and other bony landmarks of clinical significance. Materials and Method: After ascertaining the gender distinction, bilateral retromolar triangle areas were demarcated and its margins were identified. Thereafter using a magnifying zoom lens of 10X, the RMF was located. The location of RMF was assessed, dimensions measured using syringe of various gauge and their distance from the bony landmarks were noted. Result: The present study describes RMT morphology as retromolar fossa, tubercle and plateau. Retromolar plateau (61 specimen) and retromolar fossa (60 specimen) were equi-proportion, retromolar tubercle being the least common (9 specimen). Prevalence of RMF in the present study is 60.77% (79 out of 130 specimen), being highest ever reported in the Indian population. Unilateral right sided foramina were exhibited by 9.2% (12 specimen) and left sided in 3.85% (5 specimen). Bilateral RMF was present in 47.69% (62 specimen). Most common variant exhibited was 26G(0.45mm) in 41.54% of the specimens. Presence of RMF at the apex is the most common variant (30%) followed by near the base (20%). On the right side there was statistically significant association between gender and location of RMF. Mean distance between the right third molar and RMF is 4.3±2.3 and Mean distance on the left between the third molar and RMF is 4.6 ±2.3mm Conclusion: Presence of RMF and its greater dimension represent a collateral neurovascular route of mandibular canal causing inadequate analgesia and vascular complications. The close proximity of RMF with 3rd molar especially “near the base” variant; may damage the structures passing through RMF during 3rd molar extraction and causes postoperative hematomas due to rupturing of the blood vessels. Henceforth, RMT and RMF is of clinical importance in Dental and Oral & Maxillofacial Surgeries. KEY WORDS: Retromolar triangle, Retromolar foramen, Mandibular canal, Third mandibular molar.