Abnormal Maxillary Trapezoid Pattern in Human Fetal Cleft Lip and Palate

Abstract

Objective: To elucidate abnormal growth patterns of human fetal maxillae with cleft lip and palate (CLP). Subject: A total of 71 fetal maxillae with CLP were obtained from aborted human fetuses. Method: Dimensions of the maxillary trapezoid (MT), formed by the maxillary primary growth centers (MxPGC), were taken from radiographic images. The CLP dimensions were compared with maxillary trapezoid dimensions of normal fetuses from a previous study (Lee et al., 1992). Main Outcome Measures: Cleft lip subjects without a cleft palate, unilateral cleft lip-alveolar cleft or cleft palate (UCL+A/UCLP), and bilateral cleft lip-alveolar cleft or cleft palate (BCL+A/BCLP) displayed abnormal MT patterns. MT abnormalities were most marked in the BCL+A/BCLP cohort. Results: The MT growth of prenatal CLP maxillae was severely arrested, resulting in abnormal MT shape on palatal radiograms. BCL+A/BCLP subjects had a more protruded nasal septum than subjects with other types of CLPs, while UCL+A/UCLP subjects showed severe deviation of the protruded nasal septum toward the noncleft side. Cleft lip-only subjects also exhibited abnormal MT growth. Conclusion: MT is primarily involved in CLPs, so that the MT shape could be utilized as a sensitive indicator for the analysis of maxillary malformation in different types of CLPs.