Aim: The authors' objective was to prove or reject the hypothesis stating that in patients with cleft lip and palate agenesis in the lower jaw is more frequent. We monitored patients with the most frequent cleft defect, i.e. unilateral cleft lip and palate, and the most frequently missing tooth in the mandible, i.e. second premolar.
Material and method: The sample included 160 patients with unilateral cleft lip and palate either on the left or on the right side. We recorded the side of the cleft defect, patients' sex, and presence or absence of lower second premolar germ either on the leftor on the right.
The criteria included the patients' age (patients born between 1999 and 2008), at least one good quality scan taken at the age 8-11, and unilateral cleft lip and palate that is not aɸpart of aɸsyndrome. Results: Out of the 160 patients, 146 (91.3%) had established lower second premolars, in 14 (8.7%) the teeth were missing (agenetic).
In case of right side clefts, the missing lower second premolar was found either on the right side or on both sides; in case of the left side clefts, the missing lower second premolar was found either on the left side or on both sides. Conclusion: The results proved more frequent agenesis in the mandible, and show significant relationship between the cleft side and the side with missing lower second premolar.