An arch length deficiency is most commonly associated with which condition?

An arch length deficiency refers to a situation where the available space in the dental arch is insufficient to accommodate the size and position of the teeth. This condition is most commonly associated with buckly impacted canines. When canines are impacted, especially if they are positioned buccally (towards the cheek), they can disrupt the normal alignment and spacing of the other teeth in the arch. The displacement of these canines often leads to crowding of adjacent teeth, thereby creating a perceived deficiency in the arch length as the space is not adequate to accommodate the erupting canines together with the adjacent teeth.

In contrast, impacted third molars typically do not cause a significant arch length deficiency since they are posterior teeth that do not influence the overall arch space in the same manner. Mesially positioned molars can lead to crowding, but they are less directly linked to arch length deficiency compared to the primary impact of canines. Diastemas, or gaps between incisors, may indicate other dental alignment issues but are not fundamentally linked to arch length deficiency as a primary causative factor in the same way that impacted canines are. Therefore, the association of arch length deficiency with buckly impacted canines is clear and reflects the complexities inherent in dental arch relationships