Operational Analysis of Trautman's Triangle in Petroclival Region Approaches: Cone- Beam Computed Tomography Study

-OBJECTIVE: This study was conducted to evaluate the anatomical and clinical features of Trautman's triangle (TT) and to better understand the possible surgical corridor for other surgical approaches involving the petroclival region, especially the presigmoid retrolabyrinthine approach.-METHODS: In this study, morphological analysis of structures related to TT was performed from cone beam computed tomography images of 134 female and 206 male individuals aged 18e65 years.-RESULTS: The TT area was observed as 5.6% (n = 19) type I, 63.2% (n = 215) type II, and 31.2% (n = 106) type III. It was determined that 87.6% of the sigmoid sinus (SS) was lateral to the posterior semicircular canal and 12.4% was medial. It was determined that the TT area showed a positive correlation with petrous slope and a negative correlation with mastoid aeration. In other words, as the TT area increased, the petrous inclination angle also increased, but the mastoid aeration decreased. It was also found that the TT area was associated with the location of the SS and the largest TT area (164.84 + 42.29 mm2) was observed in the posteriorly located SS. -CONCLUSIONS: The relationship between TT and SS, petroclival angle, mastoid aeration, and subarcuate fossa has a very dynamic structure. Understanding the variations and clinical significance of these structures in the petro-clival region is critical in determining the surgical ap-proaches to be applied and understanding the etiology of vestibular system diseases.