Classification and phenotypic spectrum of atypical orofacial clefts – A single centre study

Orofacial clefts, among the commonest birth defects, can extend atypically onto splanchnocranium. To analyse the phenotypic spectrum of atypical orofacial clefts and relate clinical diagnosis with other topographic and pathomorphogenetic classifications, a cross sectional descriptive study was performed on 500 children aged ≤18 years with orofacial clefts over three years. Pattern of malformation and clinical diagnosis were established in children with atypical clefts. Evaluation focussed on type of cleft, laterality, dysmorphology and associated anomalies. Topographic and morphogenetic classifications were tabulated against clinical diagnosis. Statistical analysis was descriptive. Results: Among 500 children with orofacial clefts, associated or syndromic clefts were seen in 116 and atypical clefts in 21. Thus, atypical clefts constituted 4.2% of all clefts and 18.1% of associated clefts. Of children with atypical clefts, bilaterality was seen in 11 (52.4%) subjects. Oculo-auriculo-vertebral spectrum constituted the largest group with nine children. Others included Treacher Collins syndrome phenotype, amniotic band sequence, frontonasal dysplasia sequence, holoprosencephaly sequence and heminasal aplasia. A majority were male (16, i.e. 76.2%). Risk factors included advanced paternal age, young maternal age and first birth order. Neuroimaging abnormalities included semilobar holoprosencephaly, interrupted ventricular system with schizencephaly and acrania. A majority were lateral clefts corresponding to Tessier 7 (9, i.e. 42.9%). Others included oblique (6, i.e. 28.6%) and median (6, i.e. 28.6%). Morphogenetically, malar and mandibular hypoplasia were significant in nine cases each. In conclusion, atypical orofacial clefts, though rare, constitute an important group of conditions with phenotypic heterogeneity. Topographic and morphogenetic classifications based on different principles would aid in the clinical diagnosis and guide in further work up