Correction of the bilateral cleft using the sliding sulcus technique

The morphology of the bilateral cleft lip can be understood in terms of process theory and field theory. The former holds that an initial event sets in motion processes of division, deficiency, displacement, and distortion; these act on the cleft site to convert a trivial defect into the final result seen at birth. Field theory describes embryonic units that are in disarray by virtue of the cleft. A subperiosteal technique is described that combines these concepts to achieve simultaneous closure of the lip and alveolus. Primary separation of the nasal tip from the philtral-columellar unit is carried out along embryonic fusion lines.