Teeth are complex structures within the mouth, serving various purposes beyond simply chewing food. Among these, lateral teeth, also known as lateral incisors, hold a distinct place in the dental arch. These teeth are an integral part of the front dentition, helping to shape the smile and perform initial food processing. They are considered significant components of the human mouth, influencing both appearance and the beginning stages of digestion.
Where Lateral Teeth Are Found
Lateral teeth are a type of incisor, positioned in both the upper (maxillary) and lower (mandibular) jaws. In a typical adult dentition, there are four lateral incisors, two on the upper arch and two on the lower. These teeth are located directly adjacent to the central incisors, the two front-most teeth, and medial to the canines, often referred to as “eyeteeth”.
Upper lateral incisors are situated laterally from the maxillary central incisors and medially from the maxillary canines. Similarly, lower lateral incisors are positioned away from the midline from the mandibular central incisors and towards the midline from the mandibular canines. While resembling central incisors, lateral incisors are generally smaller in all dimensions except root length. Their crowns tend to be narrower and more elongated compared to the broader, more symmetrical central incisors.
The shape of lateral incisors also distinguishes them; upper lateral incisors often have more rounded incisal angles and a more convex labial surface than central incisors. The root of the lateral incisor is typically around 1.5 times the length of its crown and can sometimes taper or curve distally. This morphology allows them to fit precisely in their position within the dental arch, contributing to the overall harmony of the smile.
Their Role and Common Variations
Lateral teeth play a role in several oral functions, including the initial stages of food processing. As part of the incisor group, their primary function involves cutting and shearing food during mastication. They work alongside the central incisors to bite into food, dividing it into smaller, more manageable pieces. This action is performed by their relatively thin, sharp incisal edge.
Lateral incisors also contribute to clear speech articulation. The precise alignment and presence of these front teeth assist the tongue in forming specific sounds, such as “th,” “f,” and “v”. Any misalignment or absence of these teeth can impact how the tongue interacts with the dental arch, potentially affecting pronunciation.
Lateral teeth can exhibit common anatomical variations or developmental issues. One such variation is “peg lateral” incisors, where the tooth is noticeably smaller, underdeveloped, and often cone-shaped. This condition can result from genetic factors or developmental issues during tooth formation. Peg laterals can lead to aesthetic concerns, such as gaps or an imbalanced smile, and may also affect bite alignment.
Another variation is agenesis, which refers to the complete failure of a lateral incisor to develop. Agenesis of maxillary lateral incisors is a common dental anomaly, with prevalence varying between 1.5% and 2% in some populations, and it is frequently linked to genetic influences. The absence of these teeth can cause surrounding teeth to shift, potentially leading to misalignment, and can also impact a person’s self-perception due to the visible gaps.