Loss of Permanent First Molars in the Mixed Dentition: Circumstances Resulting in Extraction and Requiring Orthodontic Management.

Extraction of significantly compromised permanent first molars may be indicated during the mixed dentition stage of occlusal development. The purpose of this article was to review circumstances that can result in the loss of a permanent first molar-including dental caries, molar incisor hypomineralization, eruption disturbances of permanent teeth, and failure of restorative treatment to affirm that a complete dental arch is not necessary for the existence of a functional dental arch. The extraction of permanent first molar(s) with subsequent orthodontic treatment in a young patient can be considered a cost-effective alternative to placing complex restorations that require replacement over the lifespan. Approaches to establish a functional dental arch in the event of the loss of a permanent first molar(s) are outlined. Additionally, orthodontic diagnostic and treatment principles are reviewed. Case histories are provided to illustrate the clinical management of permanent first molar extractions to achieve a functional dental arch.