Ectopic bone formation as a complication of surgical rehabilitation in patients with Moebius' syndrome.
OBJECTIVE
Treatment of facial paralysis by muscular neurotization resulted in ectopic ossification in 1 of 134 cases in this department. That patient suffering from Moebius syndrome (MS) is presented. Reviewing the literature concerning MS, Hox genes and bone morphogenetic protein dysregulation, a pathogenesis of ossification in MS is suggested.


METHODS
The MS patient exhibited a congenital facial nerve palsy, which was treated by muscular neurotization (Lexer-Rosenthal). Because of postoperative ossification of scarred areas, osteotomy of the processus muscularis and mobilization of the masseter muscle was performed. Nevertheless, further ossification occurred at the interface between the mandible and zygoma and in two masticatory muscles. So, the construction of a neoarthrosis became necessary. Three years later, the iatrogenic bone defect had reossified despite of an active opening therapy.


CONCLUSIONS
Ectopic ossification after muscular neurotization seems to be restricted to patients with MS and is triggered by trauma. Molecular pathogenesis: facial malformations in MS are caused by disturbances in embryonic patterning. Failure in the development of the second pharyngeal arch leads to a spatial BMP-4 dysregulation responsible for ossification after wounding of muscle fascia. Therefore, surgical rehabilitation of facial function by muscular neurotization is contra indicated in MS patients.
Franz
Marcus
M
Institute of Pathology, Friedrich Schiller University, 07740 Jena, Germany.
Berndt
Alexander
A
Wehrhan
Falk
F
Schleier
Peter
P
Clement
Joachim
J
Hyckel
Peter
P
D000328:Adult; D005152:Facial Muscles / Q000473:pathology* / Q000601:surgery; D005158:Facial Paralysis / Q000601:surgery; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000473:pathology / Q000601:surgery; D020331:Mobius Syndrome / Q000601:surgery*; D009135:Muscular Diseases / Q000209:etiology*; D016067:Nerve Transfer / Q000009:adverse effects; D009999:Ossification, Heterotopic / Q000209:etiology*; D011183:Postoperative Complications; D013703:Temporal Muscle / Q000294:innervation / Q000473:pathology / Q000601:surgery