Impacted First and Second Permanent Molars: Overview

Impaction of a permanent tooth is a relatively common clinical occurrence in the human dentition. First mandibular molars and maxillary second molars are rarely impacted with a reported prevalence of 0–2.3% for second molars, 0.02% for the maxillary first molar, and of less than 0.01% for the mandibular first molar. The failures in their eruption mechanism may occur due to an obstacle such as the presence of a supernumerary tooth or an odontoma, lack of adequate space in the arch, an abnormal eruption path, or with idiopathic etiology. It is an asymptomatic pathology which is usually a casual discovery. Early diagnosis and treatment of permanent molars eruption disturbances contributes to optimal outcomes and favorable long-term prognosis by reduction of complication. The purpose of this is chapter is (1) to define prevalence and etiopathogeny of impacted first and second permanent molars, (2) to pinpoint the needs of earlier diagnosis, and finally (3) to highlight the treatment options.