Role of third molars in mandibular incisor crowding: An orthodontist′s perspective

Abstract

The mandibular third molars erupt after 18 years of age, are the last teeth to erupt in the oral cavity, and are the most commonly impacted teeth as well. With evolution, jaw sizes in humans have reduced, effectively reducing the maxillary and mandibular arch lengths, to accommodate terminal third molars. This has resulted in either absent or impacted third molars. Occasionally these third molars, with inadequate space for their normal eruption, are mesially tilted. This situation is more common in the mandibular arch. There are two schools of thought regarding influence of third molars on incisor crowding. The first school of thought states that mandibular third molars create an anterior component of force which leads to crowding in the anterior segment. The second school of thought suggests that the force generated by third molars is insufficient to cause anterior crowding. The aim of this review is to bring forward both concepts and allow the clinician to justify third molar extractions.