Which malocclusion requires a retro-pulsation test on the mandible?

Which malocclusion requires a retro-pulsation test on the mandible?

• A. retrognathism of the lower jaw
• B. prognathism of the lower jaw
• C. laterognathism of the lower jaw
• D. deep blocking

Answer: (B)

The main idea is to use a retro-pulsion maneuver to judge whether a forward-positioned lower jaw is due to a true skeletal forward displacement or to dental/functional factors. By attempting to move the mandible backward from its habitual bite, you’re testing how much of the forward position is locked in by the underlying bone. If the mandible resists retrusion and remains forward, that supports skeletal prognathism—the jaw itself is positioned ahead of the maxilla. If the mandible moves back easily and the bite aligns closer to normal when retruded, the forward appearance is more likely due to dental alignment or a functional shift rather than true skeletal protrusion. This distinction matters most when the clinical picture suggests a protrusive mandible. The other malocclusions—one being a retruded mandible, which wouldn’t present with a forward position needing such a test; a lateral jaw deviation (asymmetry) rather than anterior-posterior position; and a deep bite—are not primarily diagnosed or clarified by this retro-pulsion assessment.

The main idea is to use a retro-pulsion maneuver to judge whether a forward-positioned lower jaw is due to a true skeletal forward displacement or to dental/functional factors. By attempting to move the mandible backward from its habitual bite, you’re testing how much of the forward position is locked in by the underlying bone. If the mandible resists retrusion and remains forward, that supports skeletal prognathism—the jaw itself is positioned ahead of the maxilla. If the mandible moves back easily and the bite aligns closer to normal when retruded, the forward appearance is more likely due to dental alignment or a functional shift rather than true skeletal protrusion. This distinction matters most when the clinical picture suggests a protrusive mandible. The other malocclusions—one being a retruded mandible, which wouldn’t present with a forward position needing such a test; a lateral jaw deviation (asymmetry) rather than anterior-posterior position; and a deep bite—are not primarily diagnosed or clarified by this retro-pulsion assessment.