Abstract
RATIONALE: Ectopic teeth may be supernumerary, deciduous, or permanent and rarely occur in the general population, with an incidence of ≈0.1% to 1% according to the literature. This report presents a rare case of an ectopic impacted tooth in the mandibular ramus region, aiming to enhance clinical recognition of this condition and explore the etiology of the ectopic tooth. PATIENT CONCERNS: In a patient with an asymptomatic ectopic impacted tooth in the mandibular ramus region, accompanied by congenital loss of the second lower right premolar, we found an ectopic impacted tooth in the mandibular ramus region. DIAGNOSES: Ectopic teeth, impacted teeth, and congenital loss of the second lower right premolar. INTERVENTIONS: The impacted tooth was not extracted, and regular oral radiographs were obtained every year. For congenital loss of the second lower right premolar, we recommend implant restoration in the position of the second right mandibular premolar. OUTCOMES: The patient accepted our recommendation and underwent implant restoration at the position of the second right mandibular premolar. LESSONS: Asymptomatic ectopic impacted teeth in the mandibular ramus region are rare. Dental development is a complex process that is influenced by a variety of factors, including genetic or acquired factors, and is regulated at many levels and in different time periods; however, it is still not clear.