RESUMEN
Odontogenic cysts and tumors are associated with some lesions that impacted teeth are one of them. Impacted teeth are those cease to erupt before emergence. Varying incidences have been reported in different literature about this condition. The aim of this retrospective study was to achieve the sexual, location and age related distribution of odontogenic cysts and tumors and frequency of each one in relationship with an impacted tooth in order to prompt of clinician knowledge and easy selection of treatment plan. In this retrospective study, we used registration books and paraffinized blocks and slides of pathology archives of Mashhad dental school which had belonged to the patients involving with impacted teeth pathology, were evaluated from 1996-2006.Over all of these lesions were 304 cases in this period and relation between impaction of tooth and type of lesion was done by exact test. This study included 160 lesions consisting of 140 cysts [87.5%] and 20 tumors [12.5%]. Dentigerous cyst was the most common cyst [58.7%], and Odontoma was demonstrated to be the most common tumor [5%]. These lesions affected males [59.8%] more than females [41.2%] and they occurred with a pick in the second decade. The left-sided posterior mandible was more commonly involved by far. The findings of this study for Dentigerous cyst and Odontogenic keratocyst were similar to the findings of the other studies; nevertheless, Mandible and males predilection of Calcifying odontogenic cyst, one decade later involvement of Odontoma [3[rd] decade], one decade sooner involvement of Ameloblastoma [3[rd] decade], male predilection of Adenomatoid odontogenic tumor were not identical to the other studies, findings. However, more studies are recommended to achieve this purpose