An Inverted Impaction Of Central Incisor Caused By Supernumerary Tooth

Supernumerary tooth is one of the etiologies of incisors impaction. Early diagnosis and intervention are critical to gain a better prognosis. A 8-year-old female patient exhibited maxillary right central incisor impaction and dental arch crowding. CBCT examination revealed that the right maxillary central incisor was impacted in an inverted position, with a supernumerary tooth located closely behind its palatal side. The patient was accompanied by the premature loss of multiple deciduous molars and a narrow dental arch, presenting as Angle's Class II occlusion with mild overjet and overbite. The cephalometric analysis showed a skeletal Class II malocclusion, mandibular retrusion, and a vertical growth pattern. The phase I early orthodontic treatment plan involved upper dental arch expansion, space management, surgical exposure, and orthodontic traction. Considering the supernumerary tooth was proximity to the palatal side of the impacted incisor, immediate extraction of the supernumerary tooth might damage the incisor's tooth germ. After MDT consultation, it was decided to rotate the impacted incisor downward in a certain angle first, and then extract the supernumerary tooth. The results showed that the treatment plan effectively averted damage to the tooth germ. Moreover, the impacted central incisor was successfully guided to eruption and was aligned within the dental arch. This case demonstrated a specific extraction strategy for the complex supernumerary tooth and the comprehensive treatment for the impacted incisor. It highlights the significance of early treatment of the impacted inverted incisor as to guide normal tooth eruption and reduce long-term complications.