Can bruxism and malocclusion (temporomandibular joint disorder) contribute to the development of TMJ (temporomandibular joint) disorder?

Can Bruxism and Malocclusion Cause TMJ Disorder?

Yes, both bruxism and malocclusion are recognized as contributing factors to temporomandibular disorders (TMD), though they are part of a multifactorial etiology rather than sole causative agents. The relationship is complex and not purely causal, but these factors frequently co-occur with TMD and can exacerbate symptoms.

The Evidence for Bruxism as a Contributing Factor

Bruxism is frequently involved as a biomechanical factor in TMD development, particularly through occlusal overloading and parafunctional activity 1. Current guidelines specifically recommend bite plates or oral appliances "in the presence of bruxism" as part of conservative TMD management, acknowledging this relationship 2.

• Bruxism has a mean prevalence of approximately 20% in the population and is associated with muscle stiffness, muscle pain, and limitation of mouth opening—symptoms that overlap significantly with TMD 3
• In TMD patients with malocclusion, the presence of oral signs of bruxism significantly explains the degree of myalgia, disc displacement, and overall TMD severity 4
• The mechanism appears to involve chronic muscle tension and repetitive loading of the temporomandibular joint structures 1

Important caveat: While bruxism and TMD frequently coexist, a direct causal relationship has not been definitively established 3. The association is strong enough, however, that clinical guidelines consistently address bruxism management as part of TMD treatment protocols 2.

The Evidence for Malocclusion as a Contributing Factor

Specific types of malocclusion, particularly Angle Class II, are associated with increased TMD severity and specific clinical manifestations 4, 5.

• Class II malocclusion is associated with higher myalgia levels, more frequent disc displacement without reduction, and reduced maximum mouth opening (38.13 mm vs 39.93 mm in Class I) 4
• Deep bite, crossbite, and Class III malocclusions also show high prevalence of TMD symptoms including mandibular deviation, arthritic pain, and muscle tenderness 5
• Edentulous spaces and reduced vertical dimension of occlusion contribute to TMD severity, particularly in older adults 5
• Premature occlusal contacts and occlusal interferences contribute to TMD symptoms 5

Critical clinical point: Despite these associations, current high-quality guidelines explicitly recommend against routine irreversible alteration of the temporomandibular joints, jaws, occlusion, or dentition 2. This reflects the understanding that while malocclusion may contribute to TMD, correcting occlusion through irreversible means does not reliably resolve TMD and may cause harm.

The Biopsychosocial Context

The etiology of TMD is multidimensional, involving biomechanical, neuromuscular, biopsychosocial, and biological factors 1. Bruxism and malocclusion represent biomechanical contributors within this broader framework.

• Stress, anxiety, and depression frequently co-occur with TMD and may drive bruxism behavior 1
• TMD is linked with other conditions including back pain, fibromyalgia, and headaches, suggesting systemic factors 2
• Depression, catastrophizing, and other psychological factors increase the risk of TMD chronicity 2

Clinical Implications for Management

When bruxism or malocclusion is present in a TMD patient, address them conservatively as part of comprehensive TMD management, but do not pursue irreversible occlusal alterations 2.

For Bruxism:

• Use stabilization-type occlusal appliances (hard full coverage splints) worn at night 2
• Provide patient education about parafunctional behaviors and self-management strategies 2
• Address psychological factors that may drive bruxism through cognitive behavioral therapy 2

For Malocclusion:

• In skeletally immature patients with minor-to-moderate dentofacial deformities, dentofacial orthopedics may improve facial development and occlusion 2
• Orthodontic treatment with fixed appliances may establish dental occlusion after orthopedic treatment or correct minor malocclusions 2
• Never perform irreversible alterations to occlusion as primary TMD treatment 2

Conservative First-Line Approach:

• Supervised jaw exercises and manual trigger point therapy provide the largest pain reductions 6
• NSAIDs for pain and inflammation 2
• Patient education about avoiding aggravating activities, soft diet, heat/cold therapy 2, 6
• Physical therapy and jaw mobilization 2

Common Pitfalls to Avoid

• Do not assume that correcting malocclusion will resolve TMD—the relationship is associative, not clearly causal, and irreversible occlusal procedures are contraindicated 2
• Do not overlook psychological comorbidities that may be driving bruxism and contributing to TMD 2, 1
• Do not rely solely on occlusal splints despite their popularity—education and active therapies may be more beneficial long-term 2, 6
• Recognize that most TMD (85-90%) can be treated with non-invasive interventions regardless of whether bruxism or malocclusion is present 2