Morphological Variations and Laterality of Bony Projections on Cerebral Aspect of Petrous Temporal Bone: Its Anatomical and Surgical Relevance

Abstract

Introduction: Knowledge regarding projections on cerebral aspect of petrous temporal bone especially in relation to dural venous sinuses or at the site of dural attachments is required for evaluating and differentiating normal from abnormal. Aim: This study was aimed to observe the incidence and localisation of various bony projections relating to sulcus for Dural venous sinus on the postero-superior surface of petrous temporal bone. Material and Methods: The study was conducted on 260 skulls (out of which 20 were obtained from cadavers during dissection and 240 were dry skull) in the Department of Anatomy, ANIIMS from April 2016 to December 2019. The cerebral aspect of petrous temporal bone was observed for presence and localisation of projections. They were classified according to their size (Small- 3 mm), Location, laterality and its relation to sulcus for dural venous sinus. Images were taken and the data was tabulated with percentage incidence of individual observation. Results: Most of the projections seen were bilateral, 168 (64.61%), however most of the projections were seen on right side 146 (56.15%). As per their location the projections were either located along superior border, 31 (11.92%) only in relation to sulcus for superior petrosal sinus or along posterior border, 91 (35.00%) in relation to sulcus for sigmoid sinus or jugular foramen. Majority of specimens (n=138, 53.08%) showed occurrence of projections along both specified sites. Conclusion: Presence of majority of projections bilaterally suggests a symmetrical pattern which might be influenced genetically during development or due to environmental/ external factors. A profound knowledge of various projections on postero-superior surface of petrous temporal bone is required by clinicians and surgeons for management and to avoid their misinterpretation as pathological ones. These findings have a relevance in understanding functional and evolutionary anatomy, and to provide individual variations.

Keywords

• dura mater
• dural venous sinuses
• posterior cranial fossa
• sigmoid sinus
• superior petrosal sinus