A STUDY ON PREVALENCE AND PATTERN OF DENTAL ANOMALIES

치아 이상의 발생 빈도와 양상에 관한 연구

An objective definition of the anomaly is not avaliable and most investigators define the term differently or fail to describe their criterion. Because dental anomaly may lead to many complications, early detection and diagnosis of dental anomalies are essential steps in the evaluation of the child patient and in treatment planning. These procedures require detailed medical and dental histories, through clinical examination and the use of radiographs. So, this study was designed to find out the prevalence of dental anomalies. The clinical and roentgenographic examination was undertaken for 8,054 children at age from 0 to 15 years and statistical analysis was done. The results were as follows : 1. Among the examined subjects, 2,134 subjects(26.5%) showed dental anomalies. The prevalence of individual dental anomalies were as follows : supernumerary teeth 15.6%, congenitally missing teeth 6.6%, fusion 2.2%, odontoma 0.35%, microdontia 1.2%, macrodontia 0.05%, gemination 0.22%, talon cusp 0.36%, dens evaginatus 0.24%, dens invaginatus 0.15%, dilaceration 0.27%, taurodontism 0.09%, abnormal tooth position 1.7%, natal & neonatal teeth 0.92%, amelogenesis imperfecta 0.01%. 2. Significant correlations between the groups with individual dental anomalies were as follows : between group I and other groups, there was negative correlation, especially group I and group II. And the correlation coefficient between male and female showed differences. 3. For the supernumerary teeth group, the prevalence of male was higher than female(p<0.001). While for the congenitally missing teeth, macrodontia, microdontia, abnormal tooth position group, the prevalence of female was greater than male(p<0.001). 4. For the congenitally missing teeth group, the mandibular primary lateral incisor showed the highest incidence in primary dentiton, while mandibular lateral incisor in permanent dentition. In the mandible(72.5%), this site showed higher prevalence than in maxilla. In the case with deciduous congenitally missing teeth, the prevalence of successive permanent congenitally missing teeth was about 33.9%, the incidence was highest in mandibular lateral incisors. 5. Most supernumerary teeth existed on middle area and showed inverted position and unerupted state. In addition, supernumerary teeth showed higher incidence on maxilla (99.3%). 6. In the case with deciduous fused teeth, the prevalence of successive permanent congenitally missing teeth was 39.9%, while that of successive permanent fused teeth was 2.7%. And the highest rate of the prevalence (40.3%) appeared in fusion of mandibular deciduous lateral incisor and canine. 7. In the case of odontoma, the prevalence was higher in maxilla(78.6%) and anterior region(82.7%) than mandible and posterior region.