Abstract: Objective The measurement of length， depth， diameter， shape of sella turcica and the incidence of sella turcica bridges on lateral cephalograms were performed to investigate the relationship between the size， morphology and incidence of sella turcica and age and gender， which can provide theoretical information for clinical use. Methods Lateral cephalograms of patients aged 325 from Department of Orthodontics， Hospital of Stomatology， China Medical University， between 2011—2015， were selected. All the patients were divided into 4 groups according to age: 310y group， 1112y group， 1314y group， 1525y group. Every group had 400 cases. There were 1 600 cases in total. Sella structural points were located on cephalometric radiograph by Winceph 8.0 software. The morphology of sella turcica and the types of sella bridging were recorded. The relationship between sella length， depth， diameter and age， gender was analyzed by SPSS 21.0 software. Results With the increasing of the age， the length， depth and diameter of sella increased， which had no significant difference between genders in the same age groups (P>0.05). The length of sella had the largest increase during 1314y， while the depth， diameter of sella had the largest increase during 1112y. It was only slightly different in the increase of the length of sella between genders. The length of the male sella had the largest increase during 1314y， while the length of the female sella had the largest increase during 1112y. The proportion of sellar shapes—the circular， flat， oval was respectively 37.9%， 33.2%， 28.9%. The incidence of sella bridging was 12.2%. There was significant difference in the incidence of sella bridging between genders(P<0.05). Conclusion During the growth and development， the size of the sella increases with age， which has no significant difference between genders in the same age groups. No significant difference is found in the proportion of sellar shapes and genders. Statistically significant difference is found in the incidence of sella bridging between genders. The incidence of sella bridging is higher in the male than in the female.

Key words: sella turcica, sella bridging, cephalogram, linear measurement, morphological analysis