[Agenesis and the morphology and site of other teeth in the permanent dentition].
OBJECTIVE
To Investigate the relationship among anodontia, anomalously shaped teeth and reduction of teeth crown.


METHODS
The position and the number of congenitally absent teeth of 79 patients were analysed, as well as the abnormal morphology of other teeth. The width of the remained teeth was measured and compared with that of normal on base of patients being divided into four groups by the number and the position of agenesis.


RESULTS
(1)Most of the congenitally absent teeth were upper lateral incisors and lower central incisors. (2) The congenitally absent teeth of upper central incisors, upper and lower first molars were rare. While in several cases, the central incisors were lightly pet-shaped. (3) There was no significant difference in teeth size between mild hypodontia groups and normal. As the incremental degree of hypodontia, anterior teeth tended to reduce, while the size of posterior teeth was relatively stable. Upper lateral incisors, lower canines, upper second premolars, upper and lower second molars accounted most in the anomalously shaped teeth which could be often found in patients with hypodontia.


CONCLUSIONS
(1) number during evolution. (2) The developmental anomaly of teeth size, teeth morphology and teeth number might be a procedure of continuous variation and it might be different manifestation of the same mechanism.
Department of Orthodontics, School of Stomatology, Shanghai Second Medical University, Shanghai 200025, China. jiguoping31@yahoo.com.cn
Guo-ping
GP
Ji
Hui-ju
HJ
Cao
Sieng
S
Weng
Guo-hua
GH
Tang
Xiao
X
Yuan