Relationship between the positions of impacted third molars and the presence of dentigerous cysts.

The objective of this study was to assess the association between the histopathological diagnoses of dentigerous cysts and pericoronal follicles and the positions of impacted third molars. The sample comprised 151 cases, diagnosed as dentigerous cysts and pericoronal follicles. Most patients were female (70.9%), white (90.1%), and age 20 years or older (63.6%). Ninety-eight cases (64.9%) were diagnosed as pericoronal follicles and 53 (35.1%) as dentigerous cysts. Teeth that developed dentigerous cysts were predominantly located in the mandible (84.9%), in a mesioangular position (49.1%), and in the 20- to 29-year age group (66.0%). The mandible seems to be the most frequent location of impacted teeth, probably because mandibular tooth eruption is more difficult, as well as dentigerous cysts, probably because the long duration of impaction increases the exposure to inflammatory stimuli and, thus, the potential for formation of dentigerous cysts. The findings also suggest that the incidence of dentigerous cysts tends to increase with age, especially for mandibular teeth in mesioangular positions.