Steven Bender DDS
The relationship, if any, of temporomandibular joint disorders and bruxism appears to be controversial and unclear.
The evidence reviewed failed to demonstrate a relationship between bruxism and temporomandibular joint disorders in children and adolescents.
Is there a relationship between bruxism and temporomandibular disorders (TMDs) in children and adolescents?
A search of 4 electronic databases, supplemented by manual searching of listed references from each included paper, from March 1970 through June 2007 identified a total of 64 papers. Original papers, interim reports, related internet sites and textbook chapters also were considered. Two reviewers selected and reviewed the articles with a 100% consensus between the reviewers. Included studies met the following criteria: 1) the study evaluated a possible association between TMDs and bruxism and 2) the study population included children or adolescents.
Thirty articles met the inclusion criteria. Two studies found temporomandibular disorders to be unrelated to bruxism in young children. One study reported that prevention of parafunctional activity in early childhood helped reduce temporomandibular disorder related to oral parafunctional behaviors. Another reported that juvenile bruxing was self-limiting and did not progress to adult bruxism. The study also suggested that childhood bruxing was unrelated to TMJ symptoms. One study reported a significant relationship between tooth attrition and symptoms of TMD in preschool children while another found no relationship in subjects aged 10 through 18 years. . In the only longitudinal study, a positive correlation was reported between bruxing and signs of TMD in children and adolescents over a 10-year period. Finally, of 10 pain variables reported by preschool children, 8 of the variables appeared related to bruxism, 3 with thumb sucking and 2 with nail biting.
The evidence is inconclusive on whether or not a relationship exists between bruxism and TMDs.
Source of Funding:
Importance and Context:
The term “TMD” encompasses a multitude of disorders, which contributes to the confusion surrounding this topic. Disorders of the temporomandibular joints, previously believed to affect only adults, affectchildren and adolescents with equal prevalence. Prevalence estimates are based on the presenting signs and symptoms of the disorders. Functional joint overload through bruxism is a possible causative factor. The etiology of bruxism, which remains controversial, is likely multifactorial. The unreliability of a clinical assessment of bruxism results from the lack of a clear definition and ultimately reduces confidence in conclusions about any possible relationship between it and TMDs. Clinicians face a difficult issue when attempting to determine the etiology of these disorders. The presentation is often multifactorial. This review clearly demonstrates there is little available evidence to demonstrate a causal relationship between parafunctional oral behaviors and facial pain presentations. This finding substantiates the need for better classification systems and research criteria.
Strengths and Weaknesses of the Systematic Review:
This review is a narrative review rather than a systematic review. The authors’ findings were limited by the paucity of available evidence. The clinical question was not well stated making the purpose of the paper vague. However, the search methods were comprehensive and the available data was presented reasonably
Strengths and Weaknesses of the Evidence:
For this review, the quality of available evidence was poor. The 30 selected articles presented epidemiologic and prevalence rate information instead of the results from controlled studies. The definition of TMDs encompasses many different disorders, which causes prevalence rates to be highly variable.
Implications for Dental Practice:
Based upon current scientific evidence, it is unclear if any relationship exists between TMDs and bruxism. This review highlights the need to better define and classify disorders of the temporomandibular joints and related structures. Better classification of distinct TMDs will facilitate progress toward the determination of each malady’s potential causative factors. Sleep bruxism differs from awake parafunctional behaviors. Data gathered from awake subjects cannot predict sleep bruxism behaviors. Based on the limited evidence available, therapeutic treatment of TMDs should be limited to conservative and reversible treatment modalities.