Treatment of a mandibular molar with primary failure of eruption: A case report.

Primary failure of eruption (PFE) is a rare inherited disorder that is uncommon in dental research. It is characterized by failure of healthy tooth eruption, which may result in unilateral or bilateral posterior open bite. To date, the etiology of PFE has remained elusive. The present study reported the case of a 12-year-old patient exhibiting unilateral open bite of the posterior teeth, with no evidence of local or systemic complications. The patient expressed aesthetic and functional concerns regarding the occlusion. Clinical and radiological examinations revealed unerupted mandibular molars with fully formed roots located in concave bone defects, with no anatomical obstruction or other dental anomalies. Based on clinical and imaging manifestations and exclusion diagnosis, PFE was diagnosed. The affected molar was extracted and orthodontic treatment with metal self-ligating brackets was initiated following diagnosis. Notably, the patient was monitored with regular follow-up visits. Following treatment, occlusal function and dental aesthetics were improved, demonstrating the efficacy of combined surgical extraction and orthodontic management for PFE. In conclusion, the present study highlighted that patients presenting with posterior open bite should be further evaluated to exclude rare disorders, such as PFE. Early detection and intervention may enhance the management of patients, leading to favourable outcomes. However, further studies are required to establish standardized treatment protocols and to elucidate the underlying genetic mechanisms.