Monostotic Fibrous Dysplasia of the Mandible in a 9-Year-Old Male Patient Treated with a Conservative Surgical Treatment: A Case Report and 15-Year Follow-Up

Abstract

Fibrous dysplasia is a developmental disorder of the bone that originates from a genetic defect disturbing the osteogenesis leading to the replacement of normal bone with the excess proliferation of fibrous tissue. It can be associated with hyperpigmentation of the skin and endocrine disorders. Fibrous dysplasia can manifest in a monostotic form affecting one bone or in a polyostotic form involving several bones. Approximately 30% of monostotic forms are observed in the maxilla and the mandible. It frequently appears in the posterior region and is usually unilateral. It is found in teenagers and could become static after adulthood. Patients can present with swelling, facial asymmetry, pain, or numbness on the affected side. Treatment modalities vary between conservative surgical treatment, radical surgical approach, and medical treatment based on bisphosphonates. Here, we present a case of a monostotic form of fibrous dysplasia affecting the posterior left region of the mandible in a 9-year-old male complaining of gradually increased swelling on the left mandibular side of one-year duration. The diagnosis of fibrous dysplasia is established based on clinical, radiographical, and histopathological features. Conservative surgery is implemented with surgical shaving and reencountering of the bone excess to reduce the facial asymmetry. Recurrence is reported 10 years later and is also treated with a localized osteoplasty and remodeling of the bone contours. Five years later, the lesion remains stable. In conclusion, a conservative approach should be adopted as the first line of treatment for young patients suffering from monostotic fibrous dysplasia.

A Case Series and Literature Review of Craniofacial Fibrous Dysplasia

“…There are additional fibro-osseous entities, such as ossifying fibroma and cemento-osseous dysplasia [ 2 ]. FD is a benign intraosseous condition in which the medullary bone is replaced by fibrous connective tissue, resulting in underdeveloped and insufficiently calcified bone [ 7 ]. In 1938, Lichtenstein first coined the term FD [ 2 ].…”

“…It affects approximately 1:30,000 individuals [ 10 ]. The majority of cases of FD occur in the early or second decades of life, showing female prevalence 2:1 and typically having minimal progression and no symptoms [ 7 ]. If it is assumed that all FDs develop in childhood or adolescence, the majority of monostotic instances go undiagnosed until they become active or reactivate later in life, at the point where they are diagnosed for the first time [ 10 ].…”

“…Malignant transformation occurs in 0.4% to 4% of cases [ 6 ]. FD is diagnosed based on clinical, radiographic, and histological findings [ 7 ]. However, the main objective of therapy is always to maintain function, the enhancement of aesthetics by treating the fundamental defect is also a legitimate purpose [ 1 ].…”

The histological artistry of fibrous dysplasia: A case report

“…Generally, conservative treatment or correction of the deformity is deemed sufficient for controlling FD. [5][6][7] Surgical resection is considered for lesions with aggressive behavior or in case of the presence of symptoms. The pathogenesis of FD involved somatic activating mutations of the GNAS-1 gene.…”

“…4 These range from a developmental anomaly to hamartoma to a benign tumor-like process. [5][6][7] Considering the incidence rate, FD comprises only 2% of all benign tumors and tumor-like processes of the bone. 8 FD may affect a single bone (monostotic) or multiple bones (polyostotic).…”