A new computed tomography protocol to assess the olfactory cleft

Abstract

INTRODUCTION: The olfactory cleft is a region of significant importance within the nasal cavity, given the heightened focus on olfactory disorders in recent years. It is considered a 3-dimensional space that starts at the most anterior olfactory filament and ends just anteriorly to the sphenoid sinus. This study aimed to outline the profile of the olfactory cleft as an anatomical area of extreme relevance in the diagnosis of diseases of the nose, paranasal sinuses and olfactory disorders. The aim to establish parameters of radiological normality for the olfactory cleft enables us to recognize and differentiate nasal disorders by identifying the widening or narrowing of the olfactory cleft during the preoperative assessment, thus facilitating the planning of the optimal treatment. This supports a theory about the evolution and development of the nose (Evo Devo Theory) that shows the olfactory nose (ethmoid and olfactory cleft) represents the seat of most diseases of the nose and paranasal sinuses. MATERIALS AND METHODS: 700 random CT scans of the nose and sinuses have been studied. A homogeneous group of CT scans of patients without paranasal sinus diseases were included in this study, seeking to define a reference anatomical measure as a criterion for tomographic normality. Measurements of the olfactory cleft were taken in the lateral-lateral direction between the middle concha and the septum on each side of the nose cavity at three specific anatomical points in the anterior skull base in the anteroposterior direction, corresponding to the beginning, middle and end of the olfactory cleft. For data analysis, exploratory statistical techniques have been used that allowed a better visualization of the general characteristics of the data. The appropriate statstical analysis was performed using Statistical Package for Social Sciences (SPSS). RESULTS: According to the statistical analysis performed, the reference values that were found evaluating and studying the three points were: at the first point - First Olfactory Neuron Point (FONP) – was 1.3 to 2.1 mm, at the second point - Middle Point (MP) was 1.1 to 1.6 mm, and at the third point – Sphenoethmoidal recess point (SERP) was 1.1 to 1.8 mm. The average in the first point was 1.78 mm, while in the second and third points were 1.41 and 1.48 mm, respectively. CONCLUSION: It is concluded that the tomographic olfactory cleft reference values are respectively: at the first point – First Olfactory Neuron Point- 1.3 to 2.1 mm, at the second point - Middle Point - 1.1 to 1.6 mm, and at the third point – Sphenoethmoidal recess point -1.1 to 1.8 mm.