Third Molar Study

Did you know the periodontal probe is a surgical tool?

When you probe the third molar regions, you can produce data to your patient about the current state of his or her periodontal health and provide a risk estimate for future disease. Probing depths greater than 4 mm suggest the presence of early periodontal disease. If the patient elects to retain the third molars, additional follow up is indicated. Recent studies show there is a 40% chance of progression of periodontal disease.

Based on the OMS Foundation and AAOMS-funded “Third molar clinical trials,” 25- to 60% of patients with asymptomatic third molars (M3s), depending on their age or gender, had clinical evidence of periodontal inflammatory disease as evidenced by periodontal probing depths of at least 4 mm. (ref) When the M3s are retained, almost 40% of patients with periodontal disease present involving the M3s at baseline (defined as PD > 4 mm) will have clinically significant progression of periodontal disease within 2 years of follow-up.

These findings can change your practice and help you take better care of your patients.

Here are some more results of the Third Molar Clinical Trials:

  • Depending on age, 28% to 77% of patients with asymptomatic M3s will have caries. At the baseline examination, 28% of patients enrolled in the Third Molar Clinical Trials had occlusal caries. Patients with caries in M1s or M2s were more likely to have caries in adjacent M3s than patients who did not have caries in those molars.
  • In patients with M3s that are visible in the mouth, mechanical debridement did not lower the levels of pathogenic bacteria or inflammatory mediators.
  • Patients who presented with mild pericoronitis had significantly more periodontal pockets around their M3s than patients who did not have pericoronitis. When examining the entire mouth, they also had more pathologic periodontal pocketing (PD 4 mm) overall than patients who presented without pericoronitis. On average, patients without pericoronitis
  • For the M3s and adjacent M2s, the periodontal status is expected to get worse for a substantial proportion of patients.

The Third Molar Clinical Trials are just one of many research endeavors that have received significant funding from the Oral and Maxillofacial Surgery Foundation and AAOMS. The OMS Foundation approved $680,000 in funding for 2016 for Research Support Grants, Student Research Training Awards, support of the AAOMS Faculty Educator Development Awards, and in support of the AAOMS Clinical Trials Methods Course. The Third Molar Clinical Trials was the umbrella project aimed at generating data on management of patients with M3s. The studies produced strong evidence that even asymptomatic unerupted and partly erupted third molar teeth may have significant bacterial colonization with periodontal pathogens and associated periodontal pathology. As dentists, we recognize periodontal probing as the gold standard for diagnosing and measuring periodontal pathology.

The Third Molar Clinical trials was a colossal undertaking, involving 24 non-surgeon investigators from multiple disciplines and numerous oral and maxillofacial surgeons from two major universities. Initially planned for 5 years, the project led to such a wealth of meaningful clinical data that the studies were funded by the AAOMS and the OMS Foundation continuously from 1998 until 2012. Total support from the OMS Foundation was $1,400,000.

Comprehensive data was collected. There were two longitudinal studies involving subjects retaining asymptomatic third molars and subjects with minor symptoms of pericoronitis related to their M3sA third prospective observational clinical trial followed the short term recovery– 14 days after removal of asymptomatic and symptomatic M3s. Investigators also analyzed cross-sectional data relating to M3s from subjects enrolled in four major large cohort population studies that were conducted by other researchers for purposes other than the study M3s.

At the conclusion of the Third Molar Clinical Trials, more than 130 publications had been produced, including abstracts of studies presented at AAOMS, The American Association for Dental research, and The American Association of Orthodontists meetings, and peer reviewed journals. Recently, three papers based on the Third Molar Clinical Trials authored by OMS residents received Straumann Awards, and another paper received the 2015 Daniel M. Laskin Award.

Because of the sheer volume of information, AAOMS formed the Task Force for Third Molar Summary to review and distill the findings of the Third Molar Clinical Trials into a summary report. The report indicated that the Third Molar Clinical Trials documented the presence of dental and periodontal pathology affecting both asymptomatic and symptomatic M3s. View the summaries of findings.