Abstract
BACKGROUND: The relationship between chewing gum and the development of temporomandibular disorders (TMD) and other jaw anomalies presents a contentious topic within dental and orthodontic research communities. This systematic review aimed to synthesize the available evidence regarding the association of gum chewing with the incidence of TMD and jaw anomalies. METHODS: Adhering to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we conducted a comprehensive review across six electronic databases-PubMed, EMBASE, Cochrane Library, Web of Science, Scopus and PsycINFO. The studies were chosen based on predetermined inclusion and exclusion criteria, with quality and bias assessments performed on each included investigation. Data extraction and synthesis focused on the relationship between gum chewing habits and the occurrence of TMD symptoms. RESULTS: The review included 8 investigations, yielding mixed outcomes. Some studies within this review indicated no direct causative link between the act of gum chewing and the development of TMD-related symptoms, suggesting that symptoms were transient and subsided with the cessation of gum chewing. Conversely, other research suggested a dose-response relationship where increased frequency and duration of gum chewing were associated with escalated TMD symptoms, such as muscle discomfort and hypertrophy. Notably, several studies highlighted the resilience of jaw musculature to adapt to the stress of chewing in individuals without pre-existing TMD, which might be indicative of a protective adaptive response. CONCLUSIONS: The association between gum chewing and TMD is complex and multifaceted. Evidence from this systematic review suggests a spectrum of effects, from negligible impact to a dose-dependent relationship between gum chewing and TMD symptomatology. THE PROSPERO REGISTRATION: CRD42024553227.