A nomogram for assisting in diagnosing mouth breathing based on maxillofacial surface electromyographic activity

Objective: A nomogram based on maxillofacial surface electromyographic (sEMG) activities was developed to assist in diagnosing mouth breathing (MB). Methods: Differences in maxillofacial sEMG activities between MB and nasal breathing (NB) subjects were compared across a sample of 250 participants to identify MB diagnostic factors, a nomogram was developed to assist in diagnosing MB. Results: In the univariate analysis, there were significant differences in sEMG activity of masseter muscle with the lips closed lightly, orbicularis oris superior during rest, orbicularis oris superior with the lips closed lightly (OOS3), orbicularis oris superior during swallowing, mentalis muscle during rest, mentalis muscle during maximal intercuspation (MT2), mentalis muscle with the lips closed lightly (MT3) and mentalis muscle during swallowing between the MB and NB groups. Multivariate analysis revealed that OOS3 and MT3 were independent risk factors for MB, while MT2 might be a protective factor against MB. The nomogram exhibited a good clinical application value with an area under the ROC curve of 0.774 (95% CI 0.713–0.834) and fitted calibration curves. Conclusion: MB could affect maxillofacial sEMG activities. We developed a nomogram to assist in diagnosing MB in the clinic. Clinical significance: The nomogram can help clinicians diagnose MB quickly and easily, providing a more effective way to diagnose children with MB early so that they can receive timely treatment and block abnormal neuromuscular reflexes early, thereby avoiding the harmful effects of MB.