[Familial expansive osteolysis otological and dental manifestations of genetic origin]

OBJECTIVES

Familial Expansive Osteolysis (FEO) ist a rare autosomal dominant bone dysplasia. The disease can show general and focal skeletal alterations, the latter having a predominantly peripheral distribution. Onset occurs after the second decade of life.

PATIENTS AND METHODS

We present the study, of 30 years, of a family consisting of 49 members covering five generations.

RESULTS

Among the 35 members studied, 18 have familial expansive osteolysis (FEO). The first clinical sign of the condition is transmission deafness at an early age. The features of the teeth has a unique and characteristic appearance. Thinning of the cortical bone leads to severe, painful, disabling deformities. Serum alkaline phosphatase, and urinary hydroxyproline and deoxipyridinoline are elevated. Calcium and parathyroid hormone are normal. Treatment with diphosphonates, calcitonin and vitamin D has been unsuccessful. We present the surgical technology and the results to short and long term of 13 interventions on 8 patients.

CONCLUSION

Progressive osteoclastic reabsorption accompanied by weak osteoblastic activity results in medullary expansion characterized by rarefaction of the bone marrow, which is replaced by fibrous tissue and fat. FEO is histologically similar to Paget disease, but the age of onset, the distribution of the bone lesions, the dental and middle ear alterations, and the clinical progression are different. These features also differentiate FEO from fibrous dysplasia, fibrocystic osteitis and imperfect osteogenesis. The gene responsible for FEO is located in the 18q21-22 chromosome region. Mutations in TNFRSF11A, the gene encoding receptor activator of nuclear factor-kappa-B (RANK), has been recently identified as the cause of FEO. A duplication of 18 base pairs in exon 1 of the TNFRSF11A gene suggests that this corresponds to the site of the anomaly and can be considered a "hot spot" for mutations.

Technique pour la suppression de la canule après laryngectomie totale sous-cricoïdienne

It is possible to obtain a permanent gaping tracheostoma after a total sub-cricoid laryngectomy by grafting the hyoïde bone at approximately 1 cm above the stitching of the trachea to the skin with its concavity leaning downwards and overlapping the trachea. First it has to be freed from the muscular intertions and if possible of the perioste: afterwards the distal half of the big horns is cut, as well as the edges of the bone, in order to obtain a large area of spongious bone. The extraction of the hyoïde bone creates no functional trouble. This simple technic, which does not take much time and gives certain advantages, is worthwhile systematically with all patients who have to undergo a total sub-cricoïdienne laryngectomy.