Introduction: Hypodontia is one of the most common developmental anomalies. This study aimed to evaluate the variations of radiographic dental development in a group of Iranian children with dental agenesis.
Materials and Methods: This study evaluated 1230 Orthopantomographs (OPGs) for agenesis of permanent teeth obtained from the patients aged between 8 and 18 years. Then the difference between Dental Age and Chronological Age (DA-CA) of the samples with full dentitions and affected with dental agenesis were compared. Dental age w::as char::acterized by root and crown development according to Häävikko’s method and the chronological age was determined by subtracting the date of birth from the date of acquiring the OPG. The obtained data were analyzed using Independent t test. 
Results: The prevalence of tooth agenesis was 3.57% in study sample (59.10% females and 40.90% males). The mean (SD) of the difference between DA-CA of the hypodontia and control groups were 1.74(1.53) and 2.12(1.81), respectively. Regarding the results of Independent t test, there was no significant difference between hypodontia and control groups in terms of DA-CA (P>0.05). The Spearman test showed no correlation between delayed tooth development and hypodontia severity.
Conclusion: The development of permanent teeth in children with dental agenesis was similar to children with normal dental development. Also, there was no correlation between hypodontia severity and delayed tooth developments.