Case Report: An overlooked inverted supernumerary tooth: a rare presentation with nasal invasion and its diagnostic and therapeutic implications

Background: Supernumerary teeth (STs) are common odontogenic anomalies, while inverted STs with palatal perforation and nasal invasion are extremely rare and carry a high risk of misdiagnosis. This case highlights the value of interdisciplinary awareness and advanced imaging. Case Introduction: A 9-year-old boy with unilateral nasal obstruction (previously misdiagnosed as rhinitis) was referred to dentistry due to dental trauma. Initial panoramic X-ray identified an inverted ST but lacked clarity. Subsequent cone-beam computed tomography (CBCT) with multiplanar reconstruction and 3D segmentation confirmed an inverted ST in the anterior maxilla with palatal perforation and nasal invasion. The tooth was extracted via a minimally invasive palatal approach guided by a 3D model, resulting in immediate resolution of nasal symptoms and a good postoperative recovery. Conclusion: Odontogenic causes must be included in the differential diagnosis for children with refractory unilateral nasal symptoms, highlighting the critical need for interdisciplinary collaboration between dentists and otorhinolaryngologists. While panoramic X-ray is a useful preliminary screening tool, CBCT is essential-not only for accurate preoperative diagnosis and safe, minimally invasive surgical planning but also for postoperative confirmation of complete removal.