What is physiological mandibular forward shift in concave facial profiles?
Physiological mandibular forward shift is often associated with Class III malocclusion and typically presents in patients with a concave facial profile.
According to Prof. Gang Shen’s Diagnostic Classification of Malocclusion, concave profiles involving a physiological mandibular forward shift are primarily attributed to mandibular?positioning?originated factors. These cases typically show a fully mesial molar relationship, and the mandible protrudes sagittally.
Similar to facial convexity caused by mandibular retrusion, facial concavity with a forward mandibular shift often shows a flattened, horizontally rectangular mandibular body on lateral cephalograms. This characteristic is collectively referred to as “Reverse Three Depth”.
*Note: Three Depth?refers to deep overjet, deep overbite and deep curve of Spee.