Maxillonasal Dysplasia

Binder syndrome is a rare developmental anomaly, affecting primarily the anterior part of the maxilla and nasal complex.

Epidemiology

Binder syndrome occurs in less than one birth in 10,000 but is probably underdiagnosed.

Clinical description

Affected individuals typically have an unusually flat, underdeveloped midface (midfacial hypoplasia), with an abnormally short nose and flat nasal bridge, underdeveloped upper jaw, relatively protruding lower jaw and/or a 'reverse overbite'' (or class III malocclusion). Hypoplasia of distal phalanges of fingers was reported in some cases.

Etiology

The etiology and pathogenesis of Binder syndrome remains uncertain.

Differential diagnosis

Phenocopies of Binder syndrome have been described in children exposed in utero to phenytoin or to vitamin K deficiency, being induced either by drug (anticoagulants) or by biliary lithiasis. Some authors consider Binder syndrome as an allelic form of chondrodysplasia punctata. Others suggest that Binder type maxillonasal dysplasia does not represent a distinct disease entity or syndrome, but rather is a nonspecific abnormality of the nasomaxillary regions.

Antenatal diagnosis

Prenatal diagnosis by two and three-dimensional ultrasound is possible (visualization of flat profile; bone hypoplasia) from 20-22 weeks of gestation.

Genetic counseling

Most reported cases were sporadic. A few cases of recurrence in pedigrees could be explained by either autosomal recessive or dominant inheritance with reduced penetrance or by multifactorial etiology.

Management and treatment

Since the degree of malformation in Binder syndrome varies significantly, surgical correction (orthodontic, plastic surgery) needs to be tailored individually.