Appearance
The crown of the canine has no occlusal surface but a cusp tip with two incisal edges. If you look at the canine from the vestibular side (from the outside, or from the inside of the lips or cheeks), you can see that the surface of the canine is divided in two. Both facets form a very flat angle to each other.
This middle edge is also the kink along which the dental arch bends and runs backwards. On the palatal side of the upper jaw (the side facing the palate) and the lingual side of the lower jaw (the side facing the tongue), two strong rims are visible, mesial and distal, which join together with the central ridge in the middle to form a strong tuberculum. Mesial always means towards the center of the dental arch, distal means the surface facing away from the center of the dental arch.
The distal incisal edge of the canine is slightly longer than the mesial one, and also forms a slightly flatter angle. The proximal surfaces are triangular in canines. Proximal surfaces are the surfaces where two adjacent teeth touch.
In the course of life, the proximal surfaces become flatter and wider, the tip of the canine flattens out and is not quite as pointed. Both are normal signs of wear and tear that normally do not require treatment. Canine tips are also the first to disappear in patients with bruxism.
They are simply crunched off. (Bruxism is the technical term for grinding) The root of the canine in the upper jaw is the longest in the whole jaw. In the upper jaw, it can even reach almost to the sinuses.
Canines have in almost all cases only one root canal. The root itself is oval and inclined distally. The roots of the lower canine are shorter than those of the canines in the upper jaw.
Functions
The canines play a very important role in chewing. In closed rows of teeth, the cheek teeth of the lower and upper jaw touch each other. If the lower jaw is now pushed to the left, as it is inevitable when chewing, the contact between the molars disappears.
The canine glides with its tip on its counterpart in the other jaw and thus a small gap is created between the molars of the upper and lower jaw. The canine teeth ensure that the upper and lower jaws cannot remain pressed together with the molars when the lower jaw is moved to the right or left. This prevents that too strong forces can act on the cheek teeth when chewing.
The consequence of continuous excessive force on the teeth is loosening of the teeth, which is more than undesirable. The whole levering out of the jaws by the canines is called anterior canine guidance. This guidance is very important and should always be maintained if possible.
The tips of the canines become flatter in the course of life, but this is normal and does not require treatment. Under certain conditions, the tip of the canine canine can be capped as part of an orthodontic treatment if the tooth is to replace a missing anterior tooth for aesthetic reasons. Functionally, in this case an attempt should be made to restore the above-mentioned anterior canine at least in part by grinding in the tooth with a premolar.
When fabricating crowns or bridges, which also include the canine, the dental technician should make sure that the anterior canine guidance is maintained or restored. In the case of total dentures, the experts are not yet in agreement as to whether anterior canine guidance should be aimed at or not. The canine is very important for aesthetics and function, therefore in case of extraction during an orthodontic treatment a premolar should be removed to make room. Premolars cannot be transformed optically very well into canines, whereas canines can be considered as anterior teeth after grinding the tip.
