facial clefting – atypical
description
atypical forms of facial clefting have been described between the mouth and ears – oro-auricular – and between the mouth and eyes – oro-ocular. these disruptions are the least common types of facial cleft but carry specific diagnostic considerations. oro-auricular clefts occur with incomplete merging of maxillary and mandibular processes, and are otherwise known as lateral clefts of the mouth. there are several syndromic associations, trisomy 13 and less commonly 18. oro-orbital clefts do not follow the normal lines of facial fusion and may be more bizarre, leading to disruption and distortion of normal anatomy, particularly of the eye and nose. they have been classified by tessier. many are a consequence of amniotic band syndrome; others can be attributed to defective closure of the cranial neural tube. atypical clefts associated with the amniotic band sequence have frequent association with other major defects, particularly those of the cns e.g., anencephaly, encephalocele, and limb amputations.
diagnosis
traditional scanning planes in sagittal, parasagittal and coronal sections should reveal the topography of these atypical facial clefts. associated abnormalities of the face, such as micro- or anophthalmia, anomalous eye-spacing and nasal deformities may be present, in addition to a deficient calvarium and cns abnormalities. close survey of the amniotic cavity may highlight these fibrous bands leading to restrictive fetal movement, limb amputation and body wall defects such as gastroschisis.
differential diagnosis
frontoethmoidal meningo-encephalocele may mimic an atypical facial cleft or may be found in association with it.
sonographic features
bizarre, slash-like, often deeply fissured, facial clefts which may be horizontal, vertical or random in position
fibrous, echogenic bands attached to the body of the fetus in close proximity to the aberrant structures
associated severe cns abnormalities such as anencephaly, encephalocele limb amputations, gastroschisis
associated facial abnormalities, such as anomalous eye size or spacing, cleft lip, or nasal deformation
associated syndromes
- amniotic band sequence
- nager
- oculoauriculovertebral
- treacher-collins
references
- lettieri j in: human malformations and related anomalies oxford university press, pp 367-375
- hughes rm, benzie rj amniotic band syndrome causing fetal head deformity prenatal diagn 4:447-450
- borluni kg amniotic band syndrome in second trimester associated with fetal malformations prenatal diagn 4:311-314
- higginbottom mc, jones kl, hall bd, smith dw the amniotic band disruption complex: timing of amniotic rupture and variable spectum of consequent defects j pediatr 95:544-549
- chen h, gonzalez e amniotic band sequence and its neurocutaneous manifestations am j med genet 28: 661-673