Removal of Symptomatic Third Molars May Improve Periodontal Status of Remaining Dentition
Subjects and Methods: Healthy subjects (ASA I and II) 18 to 35 years old with mild symptoms of pericoronitis affecting at least one mandibular 3rd molar were recruited for an IRB-approved study. Exclusion criteria were major symptoms of pericoronitis, generalized periodontal disease, obesity, systemic antibiotic use within two months, and tobacco use. Subjects who had all four 3rd molars removed with follow-up at least three months later were included in these analyses.
Clinical and demographic data were collected at enrollment and post-surgery. Full mouth periodontal probing was conducted at 6 sites per tooth. A periodontal probing depth of at least 4 mm (PD4+) was considered an indicator variable for periodontal pathology.
Outcome variables included the number of subjects with at least one PD4+ probing site in the third molar region and the number and extent of PD4+ sites on the D2M and on teeth more anterior in the mouth. These variables were assessed at the subject and jaw levels. Data was analyzed using McNemar’s test and outcomes are reported with descriptive statistics.
Results: Median age of the 51 subjects was 22 years (IQR 20.2-25.8). Fifty-five percent were male; 61% were Caucasian.
Periodontal probing depths improved significantly after surgery on the distal of 2nd molars (D2M): 86% of subjects had at least one D2M PD4+ at enrollment as compared to only 26% of subjects post-surgery (p <0.001). The median number of D2M PD4+ was reduced from 2 (IQR 1-3) to 0 (IQR 0-1) after third molar removal. This effect was more pronounced in the mandible. Extent (percent possible) of mandibular D2M probing sites that had PD4+ was reduced from 48% to 10% after third molar removal.
Interestingly, periodontal probing depths anterior to the D2M also improved after third molar removal. Fifty-nine percent of subjects had at least one PD4+ anterior to the 3rd molar region at enrollment as opposed to only 22% post-surgery. The median number of PD4+ anterior to the D2M on a subject level was reduced from 1 (IQR 1-5) to 0 (IQR 0-0). The extent of mandibular probing sites anterior to the D2M with PD4+ dropped from 3.4 to 0.9% post-surgery.
In terms of full mouth absolute number of PD4+ probing depths, our subjects experienced a reduction from a median of 7 (IQR 4-11) to 0 (IQR 0-2).
Conclusions: Removal of 3rd molars in subjects with mild pericoronitis appears to improve the clinical periodontal status of the distal of 2nd molars and teeth more anterior in the mouth.
References:
1. Dodson TB, Richardson DT: Risk of periodontal defects after third molar surgery: an exercise in evidenced-based clinical decision making. Oral Maxillofac Surg Clin NA 19:93, 2007
2. Krausz AA, Machtel EE, Peled M: Effects of lower third molar extraction on attachment level and alveolar bone height of the adjacent second molar. Int J Oral Maxillofac Surg 34:756, 2005