For planning, six facial features helped to plan for alteration of OP in orthognathic surgery: (I) facial type; (II) upper incisor display at rest regards to upper lip; (III) dental and gingival display on smile; (IV) fullness and soft tissue support in the lips and paranasal region; (V) chin projection regarding to lips; and (VI) lower lip projection.
The chin projection regarding lower incisor inclination helped to regulate the amount of OP alteration; because we believe higher discrepancy between these structures, greater alteration of OP would be necessary.
Facial analysis showed a well-positioned maxilla despite a hypodivergent face pattern, with a reduction of tooth exposure upon smiling, and favorable chin projection
associated with accentuated and deep labiomental fold due to retrusion of the inferior alveolar segment (Figures 1 and 2).
This loss of bony volume may contribute sagging facial skin, decreased chin projection
, and loss of jaw-line definition.