24 - Craniofacial clefts

Abstract

Congenital craniofacial clefts are abnormal disfigurements of the cranium and face occurring in varying degrees of severity but in predictable patterns based upon understanding of embryology. Craniofacial clefts are thought to occur spontaneously, except for syndromes with clefting combinations, like Treacher Collins syndrome or hemifacial microsomia (both a combination of number 6, 7, and 8 clefts). With abnormal embryologic neuroectoderm migration and penetration, the epithelium breaks down and a facial cleft may occur. The severity of the cleft is proportional to the failure of penetration by the neuroectoderm. Tessier’s numeric classification from number 0 to number 14 (facial clefts = numbers 0–8 and cranial clefts = numbers 9–14) offers a descriptive, easy-to-understand system for rare craniofacial clefts. It is treatment-oriented and has withstood the test of time. Median craniofacial dysplasias are unique and consist of hypoplastic (tissue deficiency), dysraphia (normal tissue but clefted), or hyperplastic (tissue excess) malformations. Correction is age-related. During infancy (3–12 months), functional problems, soft-tissue clefts, and midline cranial defects (e.g., encephaloceles) may be corrected. In older children (6–9 years), midface and orbital reconstruction with bone grafting or a facial bipartition may be performed. At skeletal maturity orthognathic and final soft-tissue corrective procedures may be performed. Treatment algorithms may be grouped into: (1) midline and paramedian clefts (numbers 0–14, numbers 1–13, 2–12, or other combinations); (2) oro-naso-ocular clefts (numbers 3–11, 4–10, 5–9); and (3) lateral clefts including constellation of numbers 6, 7, and 8 clefts like Treacher Collins syndrome or craniofacial microsomia.