Detection of anatomical variations in mandible by panoramic radiography

Abstract

Aim: To assess the visibility, frequency and gender variations of mandibular canal, mental foramen, anterior loop of mental nerve, incisive canal and lingual foramen in Indian population. Material and Methods: Retrospective analysis of total 300 panoramic radiographs were selected for the study. Radiographs were analysed for the mandibular canal, mental foramen, anterior loop of mental nerve, incisive canal and lingual foramen by two independent observers and scores were recorded. Intra and inter-examiner reliability was assessed by kappa-statistics percentages of observations were obtained and Chi-square test was used to find out association of age and gender with visibility of anatomical landmarks. Results: The mandibular canal was visible in 100% of the 300 cases. Anterior looping of the mental nerve was not visible in 90% (270) of the cases, with 1.3% having good visibility. The mental foramen was moderately visible in 66% cases. The lingual foramen could not be visualized in 95.3% of the cases, with poor visibility in 0.7%. An incisive canal was observed in 33% of the cases, good visibility with only 1.3%. Contingency tables with Chi-square test showed that gender does not exert any effect on the visibility of the anatomical structures in the mental interforaminal region ( P > 0.05). Chi-square test reveled, significant difference exist between age and visibility of mandibular canal ( P Conclusion: The important conclusion drawn from the present study is that as far as mandibular canal and mental foramen is concerned, panoramic images provide sufficient information. However, it is insufficient for detection of interforamina structures especially for presurgical implant planning in the mental region and may need to be supplemented with three dimensional imaging for better visualization of the area.