Does Retaining Third Molars Result in the Development of Pathology Over Time? A Systematic Review

J Oral Maxillofac Surg. 2020 Nov;78(11):1892-1908. doi: 10.1016/j.joms.2020.06.014. Epub 2020 Jun 15.


Purpose: The present systematic review was conducted to assess the available literature on pathologies associated with third molar retention.

Materials and methods: A systematic literature search was conducted in MEDLINE (PubMed), Embase, and Cochrane Library and reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Relevant reports were selected using predefined inclusion and exclusion criteria. Pathology related to third molar retention included caries, periodontal pathology, second molar external root resorption, and pathologic widening of the third molar pericoronal space. The methodologic quality of each study was reviewed using a pathology-specific tool to assess the risk of bias.

Results: A total of 37 studies were included for qualitative analysis. The available data showed that asymptomatic retained third molars frequently become diseased with increasing age of the patient and increased retention time. Caries and periodontal pathology were most frequently observed, especially in partially erupted third molars and mesially inclined mandibular third molars. Overall, the available data were regarded as medium to fair quality evidence.

Conclusions: The available data have revealed that retained asymptomatic third molars rarely remain disease-free over time. Increasing age and, thus, increasing retention time seemed associated with greater disease prevalence. Well-designed, prospective follow-up studies are needed to substantiate the clinical management of asymptomatic disease-free third molars.

Publication types

  • Systematic Review

MeSH terms

  • Dental Caries*
  • Follow-Up Studies
  • Humans
  • Molar
  • Molar, Third*
  • Prospective Studies