True or False: A >5mm overjet is a predisposition for TMD.

True or False: A >5mm overjet is a predisposition for TMD.

• A. Not sure
• B. Depends on the case
• C. False
• D. True

Answer: (D)

A large overjet changes how the teeth meet during function and can shift the balance of forces on the jaw joint and muscles. When there is more than about 5 mm of horizontal overlap, there can be less stable intercuspation and more reliance on anterior guidance or edge-to-edge contacts, which may place unusual or uneven loads on the temporomandibular joint during closing, opening, and grinding movements. This increased or misdirected loading can contribute to muscle strain, joint wear, and symptoms associated with TMD, especially if it coexists with other risk factors like parafunctional habits, trauma, or postural issues. So, an overjet greater than 5 mm is considered a predisposition for TMD because it raises the likelihood of dysfunctional occlusal contacts and joint loading, even though it doesn’t guarantee that someone will develop TMD.

A large overjet changes how the teeth meet during function and can shift the balance of forces on the jaw joint and muscles. When there is more than about 5 mm of horizontal overlap, there can be less stable intercuspation and more reliance on anterior guidance or edge-to-edge contacts, which may place unusual or uneven loads on the temporomandibular joint during closing, opening, and grinding movements. This increased or misdirected loading can contribute to muscle strain, joint wear, and symptoms associated with TMD, especially if it coexists with other risk factors like parafunctional habits, trauma, or postural issues. So, an overjet greater than 5 mm is considered a predisposition for TMD because it raises the likelihood of dysfunctional occlusal contacts and joint loading, even though it doesn’t guarantee that someone will develop TMD.