Radiological Evaluation of Olfactory Fossa with Cone-Beam Computed Tomography

Abstract

Objectives:The aim of this retrospective study was to evaluate the morphology of the olfactory fossa in the Turkish population using cone-beam computed tomography according to Keros classification and to investigate the effect of age, gender and nasal septum deviation on the olfactory fossa. Material and Methods: Olfactory fossa (OF) were analysed in coronal sections on cone-beam computed tomography images of 385 individuals. Nasal floor (NF), medial ethmoid roof point (MERP), cribriform plate (CP) heights, CP depth and width, OF width, lateral lamella-cribriform plate angle (LLCPA), and nasal septum deviation angle (NSDA) were measured. Keros and Gera classifications were made according to the measurements. Results: According to the Keros classification, 137 of 770 OFs were type I (17.8%), 554 (71.9%) were type II, and 79 (10.3%) were type III. The most common combination was Keros type II and Gera type II (45.6%). There was a positive correlation between CP depth and LLCP angle, NF, MERP and CP heights (P ≤ 0.05). NF, MERP, and CP heights, CP depth and LLCP angle were statistically significant differences according to Keros classification (P ≤ 0.05). Only the right LLCP angle showed a statistically significant difference according to the NSD sides (P = 0.014). Conclusions:The study shows that the lateral lamella-cribriform plate angle increases as the cribriform plate depth increases. This result suggests that it may moderate the risk during endoscopic sinus surgery. Also, according to the nasal septum deviation sides, the dimensions of the olfactory fossa did not change significantly, except for the lateral lamella-cribriform plate angle.

Diagnostic usefulness of cone‐beam computed tomography versus multi‐detector computed tomography for sinonasal structure evaluation

“…Cone‐beam computed tomography (CBCT), a radiographic imaging technique that has been in use since the 2000s, was initially developed for angiography; however, its recent applications include image‐guided radiation therapy, surgical planning, and intraoperative imaging 1–4 . Currently, CBCT is most widely used in dentistry for dentomaxillofacial imaging, with increasing applications in otorhinolaryngology for the evaluation of the sinuses and temporal bone 5–10 …”

“… 1 , 2 , 3 , 4 Currently, CBCT is most widely used in dentistry for dentomaxillofacial imaging, with increasing applications in otorhinolaryngology for the evaluation of the sinuses and temporal bone. 5 , 6 , 7 , 8 , 9 , 10 …”

Risk Factors for Anterior Skull Base Injury in Endoscopic Sinus Surgery

“…The lateral lamella of the cribriform plate (LLCP) and the posterior ethmoid roof (ER) are predominantly susceptible to CSF leaks due to their delicate bone composition [5][6][7]. The Keros classification is a widely utilized clinical tool for assessing the depth of the cribriform fossa, categorizing it based on the vertical separation between the ER and the cribriform plate (CP) into three distinct types.…”

“…The Keros classification is a widely utilized clinical tool for assessing the depth of the cribriform fossa, categorizing it based on the vertical separation between the ER and the cribriform plate (CP) into three distinct types. It implies that an elongated CP is more prone to damage [7,8]. Nonetheless, the Keros system has limitations in gauging the risk of injuries to the skull base due to its inherent curvature.…”

“…Consequently, evaluating the Gera classification is advisable. According to the Gera methodology, the angle created by the lateral lamella (LL) and the horizontal plane originating from the CP is measured to determine the slope of the ER in relation to the CP, which is classified into three risk categories: Class I (>80°, low risk), Class II (45°-80°, moderate risk), and Class III (<45°, high risk) [7,9].…”