Background: Impacted tooth is common in dental practice. Dentists usually remove them if they are associated with any pathologic sign or symptom. The challenge is whether to extract the asymptomatic tooth or not. This study was conducted to determine the association between developmental odontogenic cysts and tumors and impacted and unerupted teeth, if left untreated. Methods: In this matched case-control study, 262 participants were recruited in case and control groups to evaluate the association between the presence of odontogenic cyst and tumors and unerupted and impacted teeth in patient records in the School of Dentistry, Shahid Beheshti University of Medical Sciences during 2000-2002. The controls referred to a dental radiology center for routine OPG. We also recorded the data on age, gender, the involved jaw, and type of lesion. All patients\' records were reviewed by the research director and an oral pathologist separately. The variables that were matched as confounders were age, gender, and the site of the involved jaw. Results: Results of conditional logistic regression analysis showed that the presence of odontogenic lesions was associated with impacted teeth (OR = 6.9), and not associated with the involved jaw and unerupted teeth. Conclusion: Impacted teeth could be considered as a potential risk factor for the presence of odontogenic lesions.