Moebius sequence -a multidisciplinary clinical approach

Abstract

Background: Moebius Sequence (MS) is a rare disorder defined by bilateral congenital paralysis of the abducens and facial nerves in combination with various odontological, craniofacial, ophthalmological and orthopaedic conditions. The aetiology is still unknown; but both genetic (de novo mutations) and vascular events in utero are reported. The purpose of present study was through a multidisciplinary clinical approach to examine children diagnosed with Moebius-like symptoms. Ten children underwent odontological, ophthalmological, obstetric, paediatric, orthopaedic, genetic, radiological and photographical evaluation. Five patients maintained the diagnosis of MS according to the diagnostic criteria.

Results: All five patients had bilateral facial and abducens paralysis confirmed by ophthalmological examination. Three of five had normal brain MR imaging. Two had missing facial nerves and one had missing abducens nerves. The Strengths and Difficulties Questionnaire (SDQ) showed normal scores in three of five patients. Interestingly, two of five children were born to mothers with uterine abnormalities (unicornuate/bicornuate uterus). In the odontological examination three of five showed enamel hypomineralisation. All five had abnormal orofacial motor function and maxillary prognathism. Two patients had adactyly, syndactyly and brachydactyly. None of the five patients had Poland anomaly, hip dislocation or dysplasia but all had a mild degree of scoliosis. We observed congenital club-feet, calcaneovalgus deformities, macrodactyly of one or more toes or curly toes. Pedobarography showed plantar pressures within normal ranges.

Conclusions: Adherence to standard diagnostic criteria is central in the diagnosis of MS. An accurate diagnosis is the basis for correct discussion of other relevant concomitant symptoms of MS, genetic testing and evaluation of prognosis. The multidisciplinary approach and adherence to diagnostic criteria taken in present study increases the knowledge on the relationship between genotype, phenotype and symptomatology of MS.

Keywords: Children; Moebius Sequence; Multidisciplinary Approach; Rare Disease.

Fig. 1

Consort 2010 Flow Diagram of the inclusion process

Fig. 2

The frontal facial view of two females with Moebius, maximal lip-closure. Patient no. 5 (a) have poor facial expression and was only able to force the lower lip into contact with the upper incisors, but the labial surfaces of the upper incisors remained partly uncovered. Patient no. 4 (b) have had “smile surgery” performed seen as indentations on the cheeks but was not able to close the lips

Fig. 3

Result of “smile surgery” with frontal facial view and oblique views of patient no 2 when smiling. Patient no. 2 had unilateral (right) “smile surgery” with a free gracilis muscle and nerve transfer. The left side have a minimal function of the lower branches of the left facial nerve

Fig. 4

Conebeam CT scanning with 3D-reconstruction of craniofacial structures of two patients with Moebius. Patient no. 5 (a) and patient no. 4 (b). Both have a large maxillary prognathism in relation to the anterior cranial base (ACB) thus, having relatively retrognathic mandibles. In addition, the mandibular alveolar prognathism in relation to the mandibular base is large. Patient no. 4 (b) have severely proclined upper incisors with very divergent jaw-bases opening anteriorly and a marked reduction of the maxillary inclination in relation to the ACB and an anterior open bite

Fig. 5

Hands and arm deformities of two patients with Moebius. Clinical photographs and radiographs of the hand and arm of patient no. 1 (a-d) shows terminal transverse congenital deficiency of the right forearm with a radioulnar synostosis, brachydactyly (shortness of fingers) of the five fingers on the left hand, slight syndactyly of the left second and third finger and camptodactyly (flexion contracture of the proximal interphalangeal joints) of the left fourth and fifth finger. Clinical photographs and radiographs of the hands of patient no. 3 (e-h) shows brachydacyly of all ten fingers, slight syndactyly of the left second and third finger, adactyly of the left second finger and camptodactyly of the right fourth and fifth finger

Fig. 6

Toe deformities of two patients with Moebius. Clinical photographs of the toes of patient no. 5 (a-b) shows curly toes of the left third and fourth toe and the right fourth and fifth toe. Clinical photographs of the toes of patient no. 2 (c-d) shows macrodactyly (local gigantism) of the left third and fourth toe

Fig. 7

Dynamic pedobarograms of four patients with Moebius. Patient no. 2 (a) have forefoot adduction and macrodactyly. The pedobarogram shows adduction of the first toe with the region of peak contact pressure at the third metatarsal head. Patient no. 3 (b) have calcaneovalgus position, macrodactyly and curly toes but normal pedobarogram. Patient no. 4 (c) have bilateral club feet with previous surgical treatment, calcaneovalgus position, macrodactyly and curly toes. The pedobarogram shows increased pressure in the midfoot area with a total foot peak contact pressure of 8080 mmHg. Patient no. 5 (d) have calcaneovalgus position and curly toes but normal pedobarogram