Evaluation of the relationship between the Sella Turcica dimension and the pattern of skull growth in horizontal dimension in CBCT images

Abstract

Introduction and Aim: Due to the necessity of understanding the relationship between the size of the cavity of Sella turcica and the skeletal growth pattern for the treatment of patients with orthodontic problems and due to the lack of three-dimensional evaluation of the size and shape of the cavity of Sella turcica with CBCT technique in previous studies, the aim of this study is to investigate the relationship between the size of cavity of Sella turcica in patients with skeletal malocclusions in CBCT images. Methods and Materials: CBCT radiographic images of 72 patients 15-75 years old (24 patients class I, 24 patients class II, 24 patients class III) referred to radiology department of Tabriz University of Medical Sciences were randomly selected. All images were taken with a New Tom VGi (Verona / Italy) camera with conical X-ray, 1920 x 1536 flatbed detector, 127 * 127 μm pixel size, 14-bit pixel depth and 360-degree rotation. In the used images, the patient was in a standing position. The patient's head was in vertical position and frankfurt plan was parallel to the ground. Exposure time for all patients was 3.6 seconds, scan time 18 seconds, field of view 15 × 15, kVp 110, and value of alternating current 1-20mA. For lateral cephalometric analysis of specimens, lateral cephalometric view, which can be reconstructed by software, was used and for determination of skeletal growth pattern in horizontal dimension Steiner analysis was used. Wit's analysis was also followed to evaluate more precisely and eliminate potential weaknesses of Steiner's analysis. The size of the Sella turcica cavity in horizontal dimension was calculated and recorded in mm. To measure the diameter and depth of the cavity in the multiplanar view, in the sagittal view with 0.3 mm cut thickness and 0.3 mm cut intervals, the largest observed dimension are selected. All measurements were performed with NNT viewer software 5.6. Results: The results showed that there was not significant statistically difference between mean of none of the depth and diameter variables in men and women. The mean diameter of Sella turcica between different age groups have no significant difference but The mean depth of Sella turcica in the under-16 age group is lower than its average in the over-24 age group. The difference in mean diameter and depth in all three types of malocclusion was not statistically significant. Discussion and Conclusion: The difference in mean diameter and depth of Sella turcica was not significant in the three types of classifications and in different genders. The mean depth of Sella turcica increased significantly with age.