Retrospective evaluation of the tooth number anomalies in children between the ages of 6-15 living in and around of the Trabzon

Tooth number anomalies are pathologies which are important in terms of causing functional and aesthetic disorders and that require time and effort from simple attempts to complicated interventions to ensure that this lost function and aesthetics in their treatment. This study is aimed to evaluate the prevalence and characteristics of tooth number anomalies in children aged 6-15 years living in and around of the Trabzon. The study was conducted by retrospectively examining the extraoral (panoramic) and intraoral (periapical and occlusal) radiographic, medical and dental anamnesis records of 7109 non-syndromic children aged 6-15 years, who were admitted to Karadeniz Technical University, Faculty of Dentistry, Department of Pedodontics for dental treatment between January 2019-January 2020. While evaluating the missing teeth, missing teeth caused by trauma, caries, periodontal disease, orthodontic extraction were excluded and the missing third molar teeth were not included in the study. In case of congenital absence of at least one tooth, the term "hypodontia" was used. The number of teeth greater than that described by the normal dental formula was recorded as "hyperdontia". The simultaneous occurrence of hypodontia and hyperdontia in the same person was recorded as "concomitant hypohyperdontia". The frequency and distributions according to the gender, region, side and position of the detected tooth number anomalies were analyzed. Chi-square, Fisher's exact and Mann Whitney U tests were used for statistical analysis. p<0.05 was considered significant in all analyzes. According to the data obtained, the prevalence of hypodontia was 7.7%, the prevalence of hyperdontia was 1.5%, and the prevalence of concomitant hypohyperdontia was 0.08%. It was determined that the teeth with the most common congenital missing teeth were the lower 2nd premolars (32.7%). Supernumerary teeth most commonly appeared as mesiodens in the midline of the maxilla (36.5%). As a result of the statistical analysis, it was determined that although hypoodontia was more common in girls (52.7%) than boys (47.3%), this difference between the sexes was not statistically significant (p=0.185; p>0.05). It was determined that hyperdontia was more common in boys (65.7%) than girls (34.3%), and this difference was statistically significant (p=0.001; p<0.01). The prevalence and characteristics of tooth number anomalies may differ between and within populations. Dentists need to be aware of the frequent occurrence of tooth number anomalies and give importance to clinical and radiological examination for diagnosis. Early diagnosis and multidisciplinary treatment of these anomalies are important in terms of minimizing the potential orthodontic and aesthetic problems of children and reducing the cost and duration of treatment in the long term. Keywords: Tooth number anomalies, Hypodontia, Hyperdontia, Supernumerary teeth, Concomitant hypohyperdontia, Prevalence