Which factor is NOT typically involved in TMD etiology?

Which factor is NOT typically involved in TMD etiology?

• A. Viral infection.
• B. Parafunctional habits.
• C. Occlusal disharmonies.
• D. Hormonal influences.

Answer: (C)

TMD is driven by multiple interacting factors, with strongest support for influences that increase jaw muscle load and pain sensitivity. Parafunctional habits like bruxism and clenching push the jaw muscles hard and repeatedly, which can lead to muscle strain, joint overuse, and pain. Hormonal influences, particularly fluctuations in estrogen, help explain why TMD is more prevalent in women and may affect pain perception and inflammatory responses. Occlusal disharmonies, while once emphasized, do not reliably cause TMD on their own—many people with noticeable bite discrepancies have no TMD, and many with TMD have relatively normal occlusion. Because of this inconsistent link, occlusal disharmonies are not considered a typical etiologic factor. They may influence symptoms in some individuals or interact with other risk factors, but they are not the main drivers of TMD.

TMD is driven by multiple interacting factors, with strongest support for influences that increase jaw muscle load and pain sensitivity. Parafunctional habits like bruxism and clenching push the jaw muscles hard and repeatedly, which can lead to muscle strain, joint overuse, and pain. Hormonal influences, particularly fluctuations in estrogen, help explain why TMD is more prevalent in women and may affect pain perception and inflammatory responses. Occlusal disharmonies, while once emphasized, do not reliably cause TMD on their own—many people with noticeable bite discrepancies have no TMD, and many with TMD have relatively normal occlusion. Because of this inconsistent link, occlusal disharmonies are not considered a typical etiologic factor. They may influence symptoms in some individuals or interact with other risk factors, but they are not the main drivers of TMD.