Which statement describes mandibular deflection?

Which statement describes mandibular deflection?

• A. Zig-zag movement during opening
• B. Movement to one side at end range
• C. Symmetric, centered opening
• D. Circular motion during opening

Answer: (B)

Mandibular deflection is when the lower jaw deviates to one side as it opens, usually becoming evident at the end range of mouth opening. In a healthy jaw, opening is smooth and centered, with the midline staying aligned. If one side has restricted translation or pain—common with unilateral disc derangement, joint dysfunction, or muscle imbalance—the mandible shifts toward that side as it nears full opening. So movement to one side at end range best describes this finding. The other patterns don’t fit deflection: zig-zag opening implies an erratic path, circular motion isn’t how the jaw opens, and symmetric, centered opening is normal rather than deflected.

Mandibular deflection is when the lower jaw deviates to one side as it opens, usually becoming evident at the end range of mouth opening. In a healthy jaw, opening is smooth and centered, with the midline staying aligned. If one side has restricted translation or pain—common with unilateral disc derangement, joint dysfunction, or muscle imbalance—the mandible shifts toward that side as it nears full opening. So movement to one side at end range best describes this finding. The other patterns don’t fit deflection: zig-zag opening implies an erratic path, circular motion isn’t how the jaw opens, and symmetric, centered opening is normal rather than deflected.