Normal lateral glide of the mandible is approximately how many millimeters?

• A. 10-15 mm (~¼ opening)
• B. 5-10 mm
• C. 15-20 mm
• D. 0-5 mm

Answer: (A)

Normal lateral glide reflects how far the mandible can move to the side from a centered position. In a healthy jaw, this movement happens with the ipsilateral condyle mainly rotating and the contralateral condyle translating, giving a distinct sideward shift. Clinically, this excursion is about one quarter of the maximal mouth opening. Since a typical opening is around 40–50 mm, the lateral glide falls in roughly the 10–15 mm range. That makes 10–15 mm the best match for normal lateral movement. The smaller ranges (0–5 mm or 5–10 mm) are too little for functional side-to-side motion, and a larger range (15–20 mm) is generally above normal.