Structural goals in craniofacial surgery.

Major craniofacial abnormalities can be considered as a group for purposes of operative planning. Known normal relations define what is abnormal and indicate goals to be achieved with the craniofacial operative procedures. The principle syndromes with significant facial structural changes amenable to such surgical corrective procedures are craniofacial stenoses, hypertelorism, mandibulofacial dysostoses, median facial clefts, residua of encephaloceles, and trauma. Deformities primarily involve the middle and upper thirds of the face. In planning, abnormal relations and structures must be clearly defined utilizing patient examination, x-rays, dental study models, and photography. Standards of norm indicating goals for the corrective procedure are also based on studies using these tools, data from previous publications, and measurements directly from skulls. Precise measurements about the orbits and maxillary-mandibular relation are the keystone for planning. Soft tissue, nose, and ear alterations are based on already widely known concepts of norm and symmetry. Bony interocular distance, medial intercanthal distance, height and width at the orbital rim of the bony orbits, orbital shape, orbital axis, and orbital volume as determined by measurement with an exophthalmometer are useful in determining what is to be done about the orbits. Cribiform plate level, anterior cranial base, length and contour, and size of the zygomatic arches are important dimension considerations. Paranasal sinus size and location is important. These considerations are essential prior to any major facial structural changes.