Lingual Tonsil Hypertrophy in OSA: The Role of Prior Tonsillectomy and Associated Clinical Risk Factors.

BACKGROUND

Lingual tonsil hypertrophy (LTH) is increasingly recognized as a contributor to upper airway obstruction in obstructive sleep apnea (OSA). While several etiological factors have been proposed, the potential role of prior palatine tonsillectomy remains understudied in adult OSA populations.

OBJECTIVE

To evaluate whether a history of tonsillectomy is independently associated with increased severity of LTH in adults with OSA, and to explore additional anatomical and clinical contributors.

METHODS

A cross-sectional observational study was conducted including 117 adult OSA patients evaluated via clinical, endoscopic, and drug-induced sleep endoscopy protocols. Patients were grouped by prior history of tonsillectomy. LTH was graded using the Friedman scale. Chi-squared tests assessed differences in LTH severity between groups. An ordinal logistic regression model was applied to identify independent predictors, adjusting for BMI, age, smoking, positional OSA, GERD, rhinitis, Mallampati, and Angle classification.

RESULTS

Among the participants (mean age 51.1 ± 11.1 years; 70.9% male), 26.5% had undergone tonsillectomy. Patients with prior tonsillectomy exhibited significantly greater LTH grades (χ2 = 5.88; P = .015), with a 57% increased risk of grade III to IV hypertrophy (RR = 1.57; 95% CI = 1.06-2.33). In multivariate analysis, tonsillectomy remained independently associated with LTH severity (OR = 2.54; 95% CI = 1.02-6.33; P = .045), as did smoking (OR = 2.50; P = .032), and positional OSA (OR = 2.20; P = .049). Age, BMI, GERD, rhinitis, Angle's classification, and Mallampati score were not significant predictors.

CONCLUSION

A prior history of tonsillectomy is significantly associated with greater lingual tonsil hypertrophy in adult OSA patients, independent of obesity or craniofacial structure. These findings suggest a compensatory or immunological mechanism and support individualized evaluation in anatomically driven OSA phenotypes. LTH assessment should be considered in surgical and anesthetic planning, especially in non-obese patients with prior tonsillectomy or positional OSA.