[A radiographic survey of root resorption in pulpless primary teeth]

The goal of this article is to survey the relation between root resorption types and sex, age, pulpless source, tooth position of pulpless primary central incisors. Healthy children with pulpless primary maxillary central incisors were systematically selected from the Kaohsiung Medical College Hospital Pedodontic Department. After a complete recording of age (3-6y/o), Sex (male, female), pulpless source (caries, trauma), and tooth position (#51, #61), the bisecting angle technique was used to take periapical X-ray film of pulpless primary maxillary central incisors. A total of 112 pulpless primary central incisors was collected and classified into 5 types: Type I--mild resorption Type II--end-cutting resorption Type III--semi-circumferential resorption Type IV--circumferential resorption Type V--irregular resorption 15 teeth (13.4%) were classified as type I, 27 teeth (24.1%) classified as type II, 35 teeth (31.2%) as type III, 30 teeth (26.8%) as type IV, and 5 teeth (4.5%) classified as type V. Chi-square analysis between root resorption types and sex, age, pulpless source, tooth position were performed, and two results were noted: (1) There are no relation between root resorption types and sex, age, tooth position. (2) There is a close relation between root resorption type and pulpless source. The pulpless teeth caused by caries tend to be resorbed as type III and type IV; on the other hand, the pulpless teeth caused by a traumatic source tend to behave like type I and type II.