Prevalence of mandibular third molar impaction, associated pathologies, and correlation with Temporomandibular joint morphology in Spanish Population: A panoramic radiography study

Background mandibular third molar is considered as the most frequent impacted tooth in the oral cavity. Its cooccurrence could lead to some impacts including the temromandbular joint symptoms. Therefore, the present study aimed to assess the prevalence of impacted mandibular third molar (IMTM), any associated pathologies, and their correlation with temporomandibular joint (TMJ) morphology in the Spanish population. Methods the existing records of orthopantomography images; panoramic images (OPGs) of patients visiting the Dental Hospital of the University of Barcelona, aged 18–40 years, having IMTM, were assessed, and interpreted by experienced Oral Radiologists and retrieved from September 2021 and May 2023. OPGs were screened for the type of impaction according to Winter classification system, any associated pathologies, and shape of mandibular condyle. Results out of 80 OPGs, 60% were females, and the majority (53.8%) were between 18 and 28 years of age. The prevalence rate of IMTM was 86.88%, with the left side commonly involved. On both sides, oval-shaped condyle and vertical IMTM were the most common, with dental caries and bone loss being the commonly observed pathologies. 15% cases showed sclerotic changes on both sides of TMJ. A statistically non-significant difference ( P  > 0.05) was observed between associated pathologies and condyle shape. Vertical and mesioangular, followed by horizontally impacted mandibular third molars were observed to be the most prevalent types of impaction, resulting in a statistically non-significant association ( P  > 0.05) with condylar shape. Conclusion The pattern of IMTM in the Spanish population showed the prevalence of vertical impaction, mainly on the left side of the mandible, with a female predominance. The commonly associated pathological changes are dental caries and bone loss, revealing a significant relation with the type of impaction and condyle shape.