Which of the following are well-established risk factors for TMD development?

• A. Bruxism and psychosocial stress/anxiety/depression; female sex is also commonly associated.
• B. Allergic rhinitis and high calcium intake.
• C. Low body weight and excessive hydration.
• D. High caffeine intake and prolonged sun exposure.

Answer: (A)

Bruxism and psychosocial factors like anxiety and depression are well-established contributors to developing TMD because they combine mechanical load with altered pain processing. Habitual teeth grinding or clenching increases activity and strain in the jaw muscles and the temporomandibular joint, which can lead to muscle fatigue, pain, and dysfunction over time. At the same time, psychosocial stress and mood disorders amplify muscle tension, pain perception, and coping difficulties, which can promote persistent TMD symptoms. The higher prevalence in females is consistently observed in studies and is thought to reflect a mix of hormonal influences and differences in pain processing.

The other options don’t have solid evidence linking them to TMD development. Allergic rhinitis and high calcium intake, low body weight with excessive hydration, or high caffeine intake with prolonged sun exposure aren’t established risk factors for TMD in the literature.