Objective: The purpose of this study was to investigate the possible absenc
e of teeth in the postcanine region of the upper jaw of the unoperated adul
t cleft patient,
Method: The study was performed on 266 dental casts of fully unoperated adu
lt cleft patients, The patients were divided into four groups according to
the type of the cleft: unilateral cleft lip and alveolus, unilateral cleft
lip and palate, bilateral cleft lip and alveolus, and bilateral cleft lip a
nd palate.
Results: No absence of permanent teeth in the canine and postcanine area of
the upper jaw could be found,
Conclusion: The results are in contradiction with the established hypothesi
s that absence of teeth outside the cleft area of the maxilla is due to an
unknown congenital factor. On the contrary, the findings support the hypoth
esis that surgery for the closure of the hard palate in early childhood is
the most important etiological factor for the absence of teeth outside the
cleft area in the early operated cleft patient. The superficial position of
the tooth germs (at the time of the palatal surgery), especially those of
the premolars, supports this hypothesis.