Asymmetric mandibular prognathism has varied causes; but often there is excess growth of the lower jaw (condylar head) at one of the temporomandibular joints (TMJ). When this happens, there is a primary effect on the lower jaw and secondary effects on the upper jaw and chin. The extent of deformity will be dependent on the timing of the unilateral (one sided) condylar overgrowth in relation to any further (residual) growth of the facial bones.

A combined orthodontic and surgical approach is required to improve the occlusion (bite), facial symmetry and facial proportions.

Example (figure 7).

Example (figure 8).