Dental anomalies in different cleft groups related to neural crest developmental fields contributes to the understanding of cleft aetiology.

OBJECTIVE: To analyze dental deviations in three cleft groups and relate findings to embryological neural crest fields (frontonasal, maxillary, and palatal). The overall purpose was to evaluate how fields are involved in different cleft types.
DESIGN: Retrospective audit of clinical photographs, radiographs, dental casts, and medical records. PATIENTS: Ninety individuals (30 cleft lip, 30 cleft palate, and 30 combined cleft lip and palate), aged 5-27 years. MAIN OUTCOME MEASURES: Visual evaluation of tooth number and tooth morphology.
RESULTS: Cleft lip: Dental deviations were predominantly observed in the frontonasal field. Supernumerary lateral incisors occurred significantly more often in cleft lip compared to other cleft types. Cleft palate: Dental deviations were observed in the maxillary and palatal fields indicating that both fields are involved in the development of cleft palate. Malformed roots were seen significantly more often in cleft palate. Combined cleft lip and palate: Number and type of dental deviations differed significantly from deviations in other cleft types, e.g. significantly more ageneses.
CONCLUSIONS: Cleft lip seems to be caused by a disorder in neural crest migration to the frontonasal field and cleft palate by a disorder in neural crest migration to the maxillary and palatal fields. Combined cleft lip and palate seems to be caused by a primary early defect in the cranial course and function of the notochord. The dentition was significantly different in the different cleft types supporting the view of different aetiology/genetics.