A RADIOLOGICAL STUDY ON THE TOOTH SHAPE ANOMALY

치아형태 이상에 관한 방사선학적 연구

The purpose of this study was to evaluate the prevalence and distribution according to the types of tooth shape anomalies in permanent teeth of 6,082 persons by means of analysis of the full mouth periapical radiographs. And the following results were obtained ; 1. Among tooth shape anomalies, the highest incidence was observed on dilaceration (20.14%), foll owed by dens invaginatus(3.02%), peg lateralis(1.48%), taurodontism (0.34%), dens evaginatus (0.33%), talon cusp(0.20%), fusion(0.07%) and gemination(0%) in descending order of frequency. 2. Peg lateralis, dens invaginatus and dilaceration occurred more prevalent in females, and other types of tooth shape anomalies occurred more prevalent in males. 3. Dens evaginatus and taurodontism occurred with bilateral tendency, but other anomalies occur- ed with unilateral tendency. 4. As to the involved teeth, maxillary lateral incisors were the most frequently involved teeth on peg lateralis, dens invaginatus and talon cusp. And the mandibular premolars were the most frequently involved teeth on dens evaginatus, the maxillary first molars were on taurodontism, the maxillary second premolars were on dilaceration, and the mandibular incisors and canines were on fusion.