Tonsillectomy as a risk factor of periodontitis: A population-based cohort study

Background: To determine whether patients who had undergone tonsillectomy would have higher risks of postoperative periodontitis. Methods: Data were collected from the Taiwan Longitudinal Health Insurance Dataset from 1999 to 2013, a population-based cohort study consisting of cases of newly-onset sleep apnoea, chronic diseases of tonsils and adenoids, peritonsillar abscess, and periodontal diseases. A total of 1482 tonsillectomy cases and 14,796 non-tonsillectomy controls were selected. Propensity score matching³⁷ between the tonsillectomy group and the non-tonsillectomy group was conducted to exclude the confounding effect resulting from indications of tonsillectomy. Cox proportional hazard model and subgroup analyses were conducted to identify subpopulations at risk of tonsillectomy-associated periodontitis, and a sub-outcome analysis was applied to identify the subtype of tonsillectomy-associated periodontitis. Results: A total of 648 patients who had undergone tonsillectomy and 648 out of 6509 propensity score-matched controls were retrieved, among which 230 cases in the tonsillectomy group were associated with post-surgical periodontitis (adjusted HR = 1.31, 95% CI = 1.08 to 1.59). The association persisted in a subpopulation of patients with periodontitis who received mechanical and surgical treatments for periodontitis (adjusted HR = 1.33, 95% CI = 1.09 to 1.63). The incidence of periodontitis was significantly high in the individuals who underwent tonsillectomy and was particularly high in those that were below 12 years of age (HR = 1.58, 95% CI = 1.10 to 2.27). The risk of periodontitis increased 4 years after tonsillectomy (HR = 1.82; 95% CI = 1.29 to 2.59). The majority of post-tonsillectomy periodontitis was aggressive and acute periodontitis (HR = 1.37; 95% CI = 1.10 to 1.71). Conclusions: Tonsillectomy performed in pediatric patients of < 12 years old, increased the risk of developing periodontitis. Aggressive and acute periodontitis as a long-term, postoperative adverse event took place at 4 years or longer after tonsillectomy.