Details
There are four canine teeth: two in the upper (maxillary) and two in the lower (mandibular) arch. A canine is placed laterally to each lateral incisor. They are larger and stronger than the incisors, and their roots sink deeply into the bones, and cause well-marked prominences upon the surface.
The crown is large and conical, very convex on its labial surface, a little hollowed and uneven on its lingual surface, and tapering to a blunted point or cusp, which projects beyond the level of the other teeth. The root is single, but longer and thicker than that of the incisors, conical in form, compressed laterally, and marked by a slight groove on each side. The lingual surface also presents two depressions on either side of the surface separated by a ridge in between; these depressions are known as mesial and distal lingual fossae.
In humans the upper canine teeth (popularly called eye teeth, from their position under the eyes) are larger and longer than the lower, and usually present a distinct basal ridge. Eruption typically occurs between the ages of 11 and 12.
From a facial aspect, maxillary canines are approximately 1mm narrower than the central incisor. Their mesial aspects resemble the adjacent lateral incisors, while their distal aspects anticipate the first premolars. They are slightly darker and more yellow in color than the other anterior teeth. From a lingual aspect, they have well developed mesial and distal marginal ridges and a well-developed cingulum. A prominent lingual ridge divides the lingual aspect in half and creates the mesial and distal lingual fossae between the lingual ridge and the marginal ridges. From a proximal aspect, they resemble the incisors, but are more robust, especially in the cingulum region. Incisally, they are visibly asymmetrical, as the mesial incisal edge is slightly shorter than the distal incisal edge, which places the cusp slightly mesial to the long axis of the tooth. They are also thicker labiolingually than mesio-distally. Because of the disproportionate incisal edges, the contacts are also asymmetrical. Mesially, the contact sits at the junction of the incisal and middle third of the crown, while distally, the contact as more cervical, in the middle of the middle third of the crown.
The lower canine teeth are placed nearer the middle line than the upper, so that their summits correspond to the intervals between the upper canines and the lateral incisors. Eruption typically occurs between the ages of 9 and 10 years of age.
From a facial aspect, the mandibular canine is noticeably narrower mesio-distally than the maxillary one, even though the root may be just as long(and sometimes bifurcated). A distinctive feature is the nearly straight outline this tooth has compared to the maxillary canine which is slightly more bowed. As in the maxillary canine, the mesial incisal edge (or cusp ridge) is shorter than the distal side, however, the cusp is displaced slightly lingual relative to the cusp of the maxillary canine. Lingually, the surface of the tooth is much more smooth compared to the very pronounced surface of the maxillary canine, and the cingulum is noted as less developed.
Read more about this topic: Canine Tooth
Famous quotes containing the word details:
“Different persons growing up in the same language are like different bushes trimmed and trained to take the shape of identical elephants. The anatomical details of twigs and branches will fulfill the elephantine form differently from bush to bush, but the overall outward results are alike.”
—Willard Van Orman Quine (b. 1908)
“There was a time when the average reader read a novel simply for the moral he could get out of it, and however naïve that may have been, it was a good deal less naïve than some of the limited objectives he has now. Today novels are considered to be entirely concerned with the social or economic or psychological forces that they will by necessity exhibit, or with those details of daily life that are for the good novelist only means to some deeper end.”
—Flannery O’Connor (1925–1964)
“Anyone can see that to write Uncle Tom’s Cabin on the knee in the kitchen, with constant calls to cooking and other details of housework to punctuate the paragraphs, was a more difficult achievement than to write it at leisure in a quiet room.”
—Anna Garlin Spencer (1851–1931)