Duplication of stomatodeal structures: report of three cases with literature review and suggestion for classification.

Three cases of duplications of stomatodeal structures are reported. One had an accessory mouth that could move simultaneously with his mouth at sternal notch. Another had a teeth-bearing bony mass at left maxilla with excessive upper lip and a false pouch. The third had an excessive upper lip, upper jaw with teeth, and hard and soft palate. The literature is reviewed, and a classification is suggested: type I, a duplicated mouth; type II, duplication of maxilla-upper lip or mandible-lower lip complex; and type III, centrally located, poorly developed lip-jaw duplication.