Tessier classification of facial clefts

The orbit is used as a reference in describing clefts involving soft tissue (top image) and bony structures (bottom image). Clefts 0, 14, and 30 are located on the midline axis. Facial clefts (numbers 0 through 7) are inferior to the orbit and numbered from medial to lateral. Cleft number 8 involves the lateral orbit. Cranial clefts (9 through 14) are superior to the orbit and numbered from lateral to medial. Cleft number 30 involves the mandible.