Palatal expansion in a patient with solitary median maxillary central incisor syndrome

The objective of this article was to report a clinical case of a patient with solitary median maxillary central incisor syndrome. He was treated with rapid maxillary expansion and evaluated with computed tomography. The boy, aged 6 years 7 months, had a single maxillary central incisor in the midline, posterior crossbite, prominent midpalatal ridge, indistinct philtrum, no incisive papilla, and no labial frenulum. No other systemic anomalies were found. Posteroanterior cephalometric radiography showed skeletal atresia of the maxilla that was corrected with rapid maxillary expansion. A Haas expander was used and activated twice per day (quarter turn per activation) for 15 days. The procedure was monitored with computed tomography to evaluate any effect on the intermaxillary suture and tooth. Although the crossbite was clinically corrected after the expansion, radiographs and tomographs showed no opening of the midpalatal suture. Rapid maxillary expansion resulted in neither midpalatal suture opening nor transverse increase of the maxillary skeletal base in this patient.