Objective:The aim of this retrospective study was to assess the prevalence and distribution of hypodontia in the permanent dentition in a sample of Turkish patients who referred to the Ankara Dental Hospital for orthodontic treatment.Materials and Methods:The pre-treatment orthodontic records of 2530 patients, 1382 girls (54.62%) and 1148 boys (45.38%) between the chronological ages of 7 and 16 years, were examined for evidence of hypodontia. The third molars were excluded in this study.Results:The prevalence of hypodontia in the inspected population was 5% (3.05% for girls, 1.95% for boys). The average number of the congenitally missing teeth per patient was 2.03 (1.08 for girls, 0.95 for boys). The prevalence of the congenitally missing permanent teeth was 34% for the upper laterals, 30% for the lower second premolars, 12.5% for the upper second premolars and 23.5% for the other teeth. Most patients with hypodontia (84.9%) (57.13% for girls, 27.77% for boys) had got missing either one tooth (45.23%) or two teeth (39.67%).Conclusions:The prevalence of hypodontia in girls was higher than in boys in this sample of the Turkish patients. The upper laterals and lower second premolars were consecutively the most symmetrically absent teeth. The prevalence of advanced hypodontia was lower than single and symmetrical hypodontia.

The aim of this study was to evaluate the facial type and skeletal relationships of Class I Turkish male and female adults by using Bimler cephalometric analysis. Materials and Method: The study sample included 82 randomly selected Turkish adults (42 female, 40 male) with an age range of 18-23 years. Cephalometric measurements defined by Bimler were used to determine skeletal relationships, including his suborbital facial index on lateral cephalometric radiographs. Variance analysis (ANOVA) was used for statistical assessment of the results. Results: The whole sample was found to be in the medium range according to Bimler. For all parameters, except the mandibular flexion (Cgo/CV), which showed hyperflexion with a mean 4.238 in female patients and 3.788 in male patients, Turkish adults show appropriate characteristics as defined by Bimler. There were no significant differences between men and women in most of the angular and linear measurements. Craniofacial height and depth values were significantly higher in men, showing a sexbased difference (p,0.001), whereas differences between the sexes concerning suborbital facial index (H/D) were nonsignificant. Conclusions: Ranges of Turkish population show similarity to those reported by Bimler. The whole sample was found to be in the medium range according to Bimler. Craniofacial height and depth values were significantly higher in men, showing sex-based difference. The mandible showed hyperflexion in both groups which indicates reduction of the height of the middle part of the face.