Incisors are single rooted, blade-shaped teeth. Incisors are oval to nearly circular in cross-section near the cervix; the tooth flattens into a lingual-labially compressed blade towards the occlusal surface. With wear, the enamel coating on the occlusal surface is removed to reveal the underlying dentin, surrounded by a resistant ring of enamel. This worn enamel ring is rectangular, distinguishing incisors from canines which have a diamond shaped worn surface. The labial surfaces of the incisors are convex and relatively smooth, while the lingual surfaces are more concave. A common variation in incisor form is shoveling on the lingual surface. Shoveled incisors have raised borders on their mesial and distal lingual margins and a deep excavated portion in the center of the lingual surface. Shoveled incisors are more common in some populations than others. This trait is especially common in Asian and Native American populations.
More teeth specimens can be found in the digital teaching collection. See also canines, premolars, and molars.
Each quadrant has a central incisor (I1) and a lateral incisor (I2) which differ in size. I1 is much wider and slightly taller than I2. Furthermore, I1 is more bulbous near the cervix than I2. In the lower incisors, I2 is slightly wider and taller than the I1. However, it may be extremely difficult to distinguish between I1 and I2 due to their morphological similarity.
Siding Incisors
For both upper and lower incisors, the long axis of the root angles distally when the tooth is positioned as it would be in the mouth. This root angle is most strongly expressed in the lateral incisors. In all incisors, the distal corner of the occlusal surface is more rounded than the sharper corner of the mesial side, but this is most noticeable for the upper incisors. In general, while upper incisors can usually be unambiguously sided it is not always possible to reliably side lower incisors.
Each quadrant has a central incisor (I1) and a lateral incisor (I2) which differ in size. I1 is much wider and slightly taller than I2. Furthermore, I1 is more bulbous near the cervix than I2. In the lower incisors, I2 is slightly wider and taller than the I1. However, it may be extremely difficult to distinguish between I1 and I2 due to their morphological similarity.
Siding Incisors
For both upper and lower incisors, the long axis of the root angles distally when the tooth is positioned as it would be in the mouth. This root angle is most strongly expressed in the lateral incisors. In all incisors, the distal corner of the occlusal surface is more rounded than the sharper corner of the mesial side, but this is most noticeable for the upper incisors. In general, while upper incisors can usually be unambiguously sided it is not always possible to reliably side lower incisors.
Each quadrant has a central incisor (I1) and a lateral incisor (I2) which differ in size. I1 is much wider and slightly taller than I2. Furthermore, I1 is more bulbous near the cervix than I2. In the lower incisors, I2 is slightly wider and taller than the I1. However, it may be extremely difficult to distinguish between I1 and I2 due to their morphological similarity.
Siding Incisors
For both upper and lower incisors, the long axis of the root angles distally when the tooth is positioned as it would be in the mouth. This root angle is most strongly expressed in the lateral incisors. In all incisors, the distal corner of the occlusal surface is more rounded than the sharper corner of the mesial side, but this is most noticeable for the upper incisors. In general, while upper incisors can usually be unambiguously sided it is not always possible to reliably side lower incisors.
Each quadrant has a central incisor (I1) and a lateral incisor (I2) which differ in size. I1 is much wider and slightly taller than I2. Furthermore, I1 is more bulbous near the cervix than I2. In the lower incisors, I2 is slightly wider and taller than the I1. However, it may be extremely difficult to distinguish between I1 and I2 due to their morphological similarity.
Siding Incisors
For both upper and lower incisors, the long axis of the root angles distally when the tooth is positioned as it would be in the mouth. This root angle is most strongly expressed in the lateral incisors. In all incisors, the distal corner of the occlusal surface is more rounded than the sharper corner of the mesial side, but this is most noticeable for the upper incisors. In general, while upper incisors can usually be unambiguously sided it is not always possible to reliably side lower incisors.