Primary Intraosseous Vascular Malformation in a Child with ELMO2 Mutation: Diagnostic and Dental Management Challenges

<b>Background/Objectives:</b> Vascular Malformation-Osteolytic Subtype (VMOS) is an exceptionally rare autosomal recessive disorder caused by homozygous pathogenic variants in the <i>ELMO2</i> gene, with fewer than ten genetically confirmed pediatric cases reported worldwide. This report presents the longitudinal dental management and clinical course of a child with VMOS, emphasizing the challenges of preventive and restorative care in such cases. <b>Methods:</b> A four-year-old child with a confirmed diagnosis of VMOS and a history of urgent bilateral coil embolization and surgical excision of mandibular aneurysmal bone cysts presented for dental care. The patient was followed for three years (2022-2025). Management focused on staged oral rehabilitation, preventive strategies, and restorative interventions adapted to changes across dentition stages. <b>Results:</b> At initial presentation, the child exhibited mandibular swelling, gingival hypertrophy, and a history of spontaneous intraoral bleeding. The postoperative course had been complicated by cerebral abscesses requiring prolonged intravenous antibiotics. During the primary dentition stage, full oral rehabilitation and strict preventive protocols were implemented to minimize caries and infection risk. In the mixed dentition period, the permanent incisors and molars erupted with enamel hypoplasia and developmental defects, necessitating composite restorations. Ectopic eruption and suboptimal oral hygiene, partly related to parental fear of bleeding, were also managed with reinforced preventive counseling. <b>Conclusions:</b> This case highlights the long-term dental implications of VMOS, underscoring the crucial role of the pediatric dentist in early preventive planning and individualized restorative management. Effective multidisciplinary coordination remains essential to preserve oral health and minimize complications in rare vascular syndromes with craniofacial involvement.