prevalence of eruption status of third molars in libyan students

background: the aim of the present study is to determine the number of third molars per person, angulation, level, amount of space for eruption of third molar between ramus of mandible and second molar and the eruption status of third molar in a group of libyan students, with different impaction patterns and agenesis of third molars. materials and methods: in this descriptive retrospective study, a total of 200 students (100 male and 100 female students of bachelor of dental surgery, faculty of dentistry, garyounis university, benghazi, libya) were enrolled. students who had complete complement of teeth within the age group 17–26 years were selected for this study, while those cases who had history of extraction of any of the teeth or who refused to give consent were excluded. before starting the study, ethical concern from the ethical committee, irb and informed consent from each student who underwent radiography were obtained. results: the results showed that 5% of third molars were congenitally missing. approximately 93.5% of the subjects had all four third molars, 1% had two third molars and 0.5% had one third molars with 2.5% having agenesis of all third molars. third molar agenesis showed predilection for maxilla with higher proportion in females (3%) than males (2.1%). angular position was maximum with vertical position (5.83%), with least being horizontal impactions. level of occlusal plane of third molar similar to that of adjacent tooth was seen in 44.74%, below the occlusal plane in 24.76%, totally impacted noted in 30%. conclusion: the present study showed that 33% of the teeth were fully erupted and 66% were in various stages of eruption and 5% were congenitally missing in these students. key words: dental, epidemiology, impacted molar, prevalence