Association of temporal bone pneumatization and dehiscence of facial nerve canal: A cadaveric study

Introduction: Facial nerve runs an extensive and complicated course through the temporal bone. Integrity of this nerve is affected by the anatomy of temporal bone. Hence, in-depth knowledge of facial canal and its surrounding structures is of utmost importance to avoid any iatrogenic injury during surgery of the middle ear. Temporal bone pneumatization has a great influence on pathogenesis and prognosis of temporal bone diseases. Hence, this study was planned to observe the pneumatization status of the temporal bone and whether there is any association between pneumatization of temporal bone and dehiscence of facial canal. Materials and Methods: The present study was conducted on 30 formalin-fixed adult temporal bones. Dissection of temporal bone was done in the Anatomy Department, TMMC and RC, TMU, Moradabad. Various cells groups were observed in the temporal bones. Facial canal was exposed, and any dehiscence present was then noted. Results: Out of total temporal bones studied, 20 belongs to the right side and 10 of the left side. Pneumatization status of bones was observed by the assessment of different cells present in the bone. Out of 30 bones, 19 (63.3%) bones were well pneumatized, in which 14 bones were of right side and five were of left side. About 11 (36.6%) bones were poorly pneumatized. In which, six were of the right side and five of the left side. In this study, dehiscence of the facial canal was observed in 9 (30%) temporal bones in which eight bones were well pneumatized and one bone was nonpneumatized. In our study, 21 (70%) bones showed no or insignificant dehiscence. Fisher exact test and Spearman's correlation test were applied to observe any association between the two variables. Conclusion: No association exists in between pneumatization of temporal bone and dehiscent facial nerve canal.