Prevalence of third molars determined by panoramic radiographs in a population‐based survey of adult Finns

Abstract

Objectives:The aim of the study was to examine the prevalence of third molars in panoramic radiographs in a population-based study of adults aged ≥30 years. Methods:Out of a sample of 8028 inhabitants of Finland, selected with two-staged stratified cluster-sampling method for the Health 2000 Survey, 5989 participated in clinical oral examination and panoramic radiography. Mean age was 52.5 years (SD 14.6; range 30-97 years). The following variables were included in the analysis: participant characteristics, clinical number of all teeth, and radiographic prevalence and characteristics of third molars. Statistics included chi-squared, Fisher's exact, and Kruskal-Wallis tests and SAS-SUDAAN calculations.Results: A total of 5912 third molars in 47.8% of the study population were recorded from panoramic radiographs. At least one impacted third molar was found in 21.9% of the study population. More than half (57.3%) of the remaining third molars were located in the mandible. A preponderance of participants with all third molars missing were observed in the oldest age group, women, those with lower education and those living in the countryside. Third molars or remnants thereof were observed radiographically in 3.9% of clinically edentulous study population. Conclusions:The panoramic radiographs disclosed many remaining third molars in adult Finns aged ≥30 years. One-third of the third molars located impacted which may cause unexpected need for care. K E Y W O R D Sadults, dental health, epidemiology

Investigation of the prevalence of impacted third molars and the effects of eruption level and angulation on caries development by panoramic radiographs

“…Ventä et al . reported a lower rate than the present study by including individuals over 30 years of age ( 16 ). The diagnostic method used also had an effect on prevalence.…”

“…Although some studies reported that there was no difference between gender and the prevalence of impacted third molars ( 16 , 24 ), most studies, including the present study, stated that the frequency of impacted third molars was significantly higher in females ( 25 ). The higher prevalence rates of impacted third molars in females can be attributed to the smaller size of the jaw compared to males and the lack of space for eruption.…”

“…Therefore, it was planned to investigate the prevalence and associations in a large sample of Turkish patients in the Trakya Region. Although there have been several studies investigating the prevalence of impacted third molars and the associations between their position and angulation ( 16 , 17 ), only a few studies focused on detrimental effects of impacted third molars on the adjacent tooth ( 18 - 20 ) and almost none have been conducted with such a large sample.…”

“…In the present study, the prevalence rate was 23% which is very similar to the rate of 21.9% reported by Ventä et al . ( 16 ). These conflicting prevalence rates can be explained primarily by racial differences and sampling techniques.…”