Oral Presentation of Monostotic Fibrous Dysplasia in a 4-Month-Old Male Patient: A Rare Case Report

Fibrous dysplasia (FD) is a developmental bone condition that replaces normal bone with aberrant fibrous connective tissue and immature bone trabeculae. This benign condition accounts for ∼7% of all non-cancerous bone tumours and ∼2.5% of all primary bone tumours overall. The extent of involvement determines whether it is monostotic (affecting only one bone) or polyostotic (affecting numerous bones). We present an extremely rare early presentation case of monostotic FD in a 4-month-old infant, who exhibited a gradually enlarging swelling in the lower left posterior region of the jaw over the course of one month. Clinically, the child exhibited extraoral swelling with tenderness on palpation. There were intermittent episodes of fever, but no signs of infection or other systemic symptoms. Radiographic imaging revealed a ground-glass appearance typical of FD, while MRI results confirmed the diagnosis. Due to the self-limiting nature of the disease, which typically stabilises after puberty, no immediate surgical intervention was deemed necessary. Unfortunately, follow-up was lost due to parental noncompliance. However, we called every 3 months to gather information, and there was no increase in swelling size even after 7 months. In general, treatment for monostotic FD involving the jaw is conservative, with surgical correction deferred until after skeletal maturity, and typically undertaken for aesthetic or functional reasons.