tooth agenesis code (tac)values in a sample of orthodontic patient population

Yildirim H., ÇELİKOĞLU M., Ceylan I.

Atatürk Üniversitesi Diş Hekimliği Fakültesi Dergisi, vol.20, no.1, pp.12-18, 2010 (Peer-Reviewed Journal)


Purpose: There are numerous studies about tooth 
agenesis, but most focus on the absence of teeth not 
the patterns of absent teeth. The purpose of this 
study was to document TAC values in a sample of 
orthodontic patient population. 
Material and Methods: Orthopantomograms of 
2733 orthodontic patients (1674 females and 1059 
males) between the ages of 12 and 25 years were 
examined for the evidence of hypodontia. The TAC 
method was used to determine TAC and TACoverall 
values for combination patterns of absent teeth. 
Results: It was found that 710 (26%) patients had 
1600 missing teeth, including third molars. There were 
79 combination patterns of these missing teeth. A 
number of 31 patterns were occurred more than one 
and symmetrical patterns were clearly showed in 
congenitally missing teeth. 
Conclusions: In this study, the symmetry and 
combinations of tooth agenesis in an orthodontic 
patient population by using the TAC and TACoverall 
values were performed.