Extensive Fibrous Dysplasia of Maxilla – A Case Report

Fibrous dysplasia is a disease of bone maturation and remodeling. The process in fibrous dysplasia is the replacement of normal medullary bone and cortices into a disorganized fibrous weaker bone. This bone (fibroosseous bone) is more elastic and structurally weaker than the original bone. The cause of development of fibrous dysplasia is the deletion of a bone maturation protein during embryogenesis and represents about 2.5% of all bone tumors and over 7% of all benign tumors of facial bones. This article presents a case of extensive fibrous dysplasia of the maxilla. The diagnosis was confirmed by imaging studies such as OPG and CT scan and by histopathological examination. Curettage and surgical recontouring was performed as a mode of treatment. Extensive Fibrous Dysplasia of Maxilla – A Case Report INTRODUCTION Fibrous dysplasia is an asymptomatic non neoplastic disease of bone in which normal trabeculae like osseous structure are present. In 1937, McCune and Bruch first suggested that among all of the abnormalities of bone disorders, the fibrous dysplasia should have its own place as a distinct clinical entity. Later, Lichtenstein introduced the term fibrous dysplasia as an arrest of bone maturation in which woven bone with ossification results from metaplasia of a non specific fibro-osseous type. Fibrous dysplasia is not a true neoplasm because it is self limiting. It begins its development as a fibrous replacement of the medullary bone which is gradually replaced by metaplastic woven bone that eventually matures into dense lamellar bone. Fibrous dysplasia is a disease of bone maturation and remodeling in which the resultant fibro-osseous bone is more elastic and structurally weaker than the original bone due to the abnormal growth process [1]. This lesion is related to a mutation in the gene that encodes the submit of a stimulating G protein (GS) located as chromosome 20. Due to this mutation, there is a substitution of the cysteine or the histedonian acids of the genomic DNA in the osteoblastic cells by another amino acid, arginine[3]. As a result, the osteoblastic cells will elaborate a fibrous tissue in the bone marrow instead of normal bone. Fibrous dysplasia affects the facial bones in about 30% of the patients. It represents about 2.5% of all bone tumors and over 7% of all benign tumors. The condition develops in children and teenagers primarily with few if any cases beginning after the age of 25 years [4]. The maxilla is affected more often than the mandible. Teeth are often displaced, rotated or malaligned resulting into severe malocclusion. The affected area presents as an asymptomatic diffuse expansion of the cortices. Fibrous dysplasia can be described in three major types – monostotic fibrous dysplasia, polyostotic fibrous dysplasia and craniofacial fibrous dysplasia. Monostotic fibrous dysplasia involves a single bone and accounts for 70% of fibrous dysplasia cases [7]. Polyostotic fibrous dysplasia involves several skeletal sites occurs as part of the McCune Albright syndrome. It features also skin pigmentation and endocrine dysfunctions [5]. When polyostotic form of fibrous dysplasia occurs in absence of endocrine disturbance, it has been formed Jaffe-Lichtenstein type of polyostotic fibrous dysplasia. Craniofacial fibrous dysplasia involves two or more bones of the jaw-midface skull complex in continuity. This type of fibrous dysplasia is seen relatively often in dental and oral and maxillofacial practices. It is thought to be a monostotic fibrous dysplasia of the maxilla, yet it often involves the zygoma, sphenoid, temporal bone, nasal chonchae and clivus. Alkaline phosphatase may be raised in up to 30% of patients with polyostotic fibrous dysplasia, and a dramatic rise may herald malignant degeneration. Malignant degeneration occurs in less than 1% of cases of fibrous dysplasia. The disease is self-limiting but grossly disfiguring lesions may need to be excised. Treatment is surgical recontouring for cosmetic and functional achievements [2]. CASE REPORT A 32 years old female patient attended the department of oral surgery with a chief complaint of swelling in the left side of face. Swelling was slowly progressing for the last 4 years. The swelling was causing problem with facial esthetics and difficulty in mastication. There was no past medical history and family history with similar findings of swelling. The extra oral clinical examination revealed hard swelling of about 4 cm. in size on the left side of maxilla extending from alla of the nose to the cheek area “Fig 1about here”. Intraorally the swelling is bulging in the left maxillary alveolar process with the ulceration of mucosa. There was displacement of posterior teeth “Fig 2 about here”. On palpation the lesion was non tender, hard in consistency, expansion of buccal cortical plate from canine region to second molar region. OPG and CT showed radiolucent shadow in the first premolar to second molar region. CT scan revealed a radiolucent radiopaque shadow in the posterior part of the left maxilla “Fig 3,4 about here”. Preoperatively synthetic salmon calcitonin injections in doses ranging from 50 to100 IU three times weekly for a period of 3-months were given subcutaneously to prevent excessive bleeding during operation and to induce bone formation by its anti-osteoclastic actions. The mass was removed under LA by curettage and surgical excision. The mucoperiosteal flap was raised extending from central incisor to molar region of the same side. A hard bony mass was excised by curettes “Fig 5,6 about here”. The wound was decontaminated with normal Saliva and betadine solution. Carnoy’s solution was applied as a fixative to fix the lesion. This was used to prevent any recurrence of the lesion by the necrosis of the remaining lesion.Primary closure was done with vicryl 4-0 interrupted suture. The mass was sent for histopathological examination to confirm the diagnosis. The histopathological report showed areas of cellular fibrous connective tissue and immature metaplastic bone with a woven pattern. The lesion blends with the surrounding normal bone and cortical plates “Fig-7about here”. This confirmed the diagnosis of fibrous dysplasia. Follow up of the lesion was done for one and half years for any recurrence. No recurrence was observed “Fig 8,9 about here”. DISCUSSION Fibrous dysplasia is a disease of bone in which the normal medullary bone and cortices are replaced by a disorganized form of woven bone. It is caused by the deletion of a bone matura-