"Skull and teeth of Bennett's Kangaroo (Macropus bennettii). i1, i2, i3, first second and third upper incisors; pm, second or posterior premolar (the first having been already shed); m1, m2, m3, m4, the four true molars. The last, not fully developed, is nearly concealed by the ascending ramus of the jaw." —The Encyclopedia Britannica, 1910

Bennett's Kangaroo

"Skull and teeth of Bennett's Kangaroo (Macropus bennettii). i1, i2, i3, first second and third upper…

Section of a portion of the dentine and cement from the middle of the root of an incisor tooth. Labels: a, dental tubuli ramifying and terminating, some of them in the interglobular spaces b and c, which somewhat resemble bone lacunae; d, inner layer of the cement with numerous closely set canaliculi; e, outer later of cement; f, lacunae; g, canaliculi.

Dentine and Cement

Section of a portion of the dentine and cement from the middle of the root of an incisor tooth. Labels:…

"Skull and teeth of Gray's Rat Kangaroo (Bellongia grayii). c, upper canine tooth. i1, i2, i3, first, second, and third upper incisors; pm, second or posterior premolar (the first having been already shed); m1, m2, m3, m4, the four true molars." —The Encyclopedia Britannica, 1910

Gray's Rat Kangaroo

"Skull and teeth of Gray's Rat Kangaroo (Bellongia grayii). c, upper canine tooth. i1, i2, i3, first,…

"Side view of skull of horse, with the bone removed so as to expose the whole of the teeth. PMx, premaxilla; Mx, maxilla; Na, nasal bone; Ma, malar bone; L, lacrymal bone; Fr, frontal bone; Sq, squamosal bone; Pa, parietal bone; oc, occipital condyle; pp, paroccipital process; i, the three incisor teeth; c, the canine tooth; pm1, the situation of the rudimentary first premolar, which has been lost in the lower, but is present in the upper jaw; pm2, pm3, and pm4, the three fully-developed premolar teeth; m, the three true molar teeth." — Encyclopedia Britannica, 1893

Horse Skull

"Side view of skull of horse, with the bone removed so as to expose the whole of the teeth. PMx, premaxilla;…

Illustrating the relationship of the lateral incisor tooth to the palatal cleft. A, Normal hard palate. The premaxilla is stippled; the lateral incisor occurs in the suture between it and the maxilla.B, Double cleft palate, the lateral incisor being situated on the premaxilla to the inner side of the cleft. The septum of the nose is exposed in the cleft between the maxillary bones. C, Double cleft palate, the lateral incisor being situated on the maxilla to the outer side of the cleft.

Incisor Relation to Palatal Cleft

Illustrating the relationship of the lateral incisor tooth to the palatal cleft. A, Normal hard palate.…

Median incisor teeth of left side labial (A) and lateral (B) aspects.

Median Incisor Teeth

Median incisor teeth of left side labial (A) and lateral (B) aspects.

Temporary incisor teeth of left side. A, median; B, lateral incisors.

Temporary Incisor

Temporary incisor teeth of left side. A, median; B, lateral incisors.

Unworn surfaces of upper and lower permanent incisor teeth, lingual aspect.

Unworn Incisor

Unworn surfaces of upper and lower permanent incisor teeth, lingual aspect.

Horizontal section through both the upper and lower jaws to show the roots of the teeth. The sections were carried through the bones a short distance from the edge of their alveolar borders. The upper figure shows the upper teeth, the lower figure the lower teeth. Note the flattened roots of the lower incisors, the two root canals in the anterior root of each lower molar, and the confluence of the three roots of the upper wisdom teeth.

Jaw Showing Roots of Teeth

Horizontal section through both the upper and lower jaws to show the roots of the teeth. The sections…

To show the relation of the upper to the lower teeth when the mouth is closed. The manner in which a tooth of one row usually strikes against two teeth of the opposite row, and the resulting interlocking of the teeth, is to be noted.

Teeth

To show the relation of the upper to the lower teeth when the mouth is closed. The manner in which a…

"A Tooth is one of the hard bodies of the mouth, attached to the skeleton, but not forming part of it and developed from the dermis or true skin. True teeth consist of one, two, or more tissues differing in their chemical composition and in their microscopical appearances. Dentine, which forms the body of the tooth, and 'cement,' which forms its outer crust, are always present, the third tissue, the 'enamel,' when present, being situated between the dentine and cement. The incisors, or cutting teeth, are situated in front. In men there are two of these incisors in each side of each jaw. The permanent incisors, molars, and premolars are preceded by a set of deciduous or milk teeth, which are lost before maturity, and replaced by the permanent ones. The canines come next to the incisors. In man there is one canine tooth in each half-jaw. The premolars (known also as bicuspids and false molars) come next in order to the canines. In man there are two premolars in each half-jaw. The true molars (or multicuspids) are placed most posteriorly. In man there are three molars in each half-jaw, the posterior one being termed the wisdom tooth. The figures [in the illustration] refer to months after birth."—(Charles Leonard-Stuart, 1911)

First Teeth

"A Tooth is one of the hard bodies of the mouth, attached to the skeleton, but not forming part of it…

Incisor and canine teeth of a horse. A, front, B, lateral, and C, corner incisor; D, canine teeth.

Incisor and Canine Horse Teeth

Incisor and canine teeth of a horse. A, front, B, lateral, and C, corner incisor; D, canine teeth.

The lower permanent teeth, viewed from above.

Lower Permanent Teeth

The lower permanent teeth, viewed from above.

The permanent teeth of the right side, outer or labial aspect. The upper row shows the upper teeth, the lower row the lower teeth. The wide vertical labial ridge is distinct on the upper canine and premolar teeth.

Permanent Teeth

The permanent teeth of the right side, outer or labial aspect. The upper row shows the upper teeth,…

The permanent teeth of the right side, inner of lingual aspect. The upper row shows the upper teeth, the lower row the lower teeth. The cingulum is distinct on the upper incisors and both canines, the lingual cusp on the upper lateral incisor and the upper canine.

Permanent Teeth

The permanent teeth of the right side, inner of lingual aspect. The upper row shows the upper teeth,…

"A Tooth is one of the hard bodies of the mouth, attached to the skeleton, but not forming part of it and developed from the dermis or true skin. True teeth consist of one, two, or more tissues differing in their chemical composition and in their microscopical appearances. Dentine, which forms the body of the tooth, and 'cement,' which forms its outer crust, are always present, the third tissue, the 'enamel,' when present, being situated between the dentine and cement. The incisors, or cutting teeth, are situated in front. In men there are two of these incisors in each side of each jaw. The permanent incisors, molars, and premolars are preceded by a set of deciduous or milk teeth, which are lost before maturity, and replaced by the permanent ones. The canines come next to the incisors. In man there is one canine tooth in each half-jaw. The premolars (known also as bicuspids and false molars) come next in order to the canines. In man there are two premolars in each half-jaw. The true molars (or multicuspids) are placed most posteriorly. In man there are three molars in each half-jaw, the posterior one being termed the wisdom tooth. The figures [in the illustration] refer to years after birth."—(Charles Leonard-Stuart, 1911)

Second Teeth

"A Tooth is one of the hard bodies of the mouth, attached to the skeleton, but not forming part of it…

The temporary teeth of the left side. The masticating surfaces of the tow upper molars are shown above. In the second row the upper teeth are viewed from the outer or labial side. In the third row the lower teeth are shown in a similar manner; and below are the masticating surfaces of the two lower molars. In the specimen from which the first upper molar was drawn the two outer or buccal cusps were not distinctly separated, as is often the case.

Temporary Teeth

The temporary teeth of the left side. The masticating surfaces of the tow upper molars are shown above.…

"<em>Temporary Teeth:</em> <em>A</em>, central incisors; <em>B</em>, lateral incisors; <em>C</em>, canines; <em>D</em>, anterior molars; <em>E</em>, posterior molars, <em>F</em>, central incisors; <em>H</em>, lateral incisors; <em>K</em>, canines; <em>L</em>, first bicuspids; <em>M</em>second bicuspids; <em>N</em>, first molars." &mdash; Blaisedell, 1904

Temporary and permanent teeth

"Temporary Teeth: A, central incisors; B, lateral incisors; C, canines;…

The upper permanent teeth.

Upper Permanent Teeth

The upper permanent teeth.

Diagram to illustrate the development of a tooth. I. Shows the downgrowth of the dental lamina D.L. from the surface epithelium E and the beginning of the enamel germ E.G. II. Shows the further growth of the enamel germ and its invagination. III. The enamel germ is more invaginated, and its inner layer of cells becomes columnar. A, the dental lamina, grows thinner, but near its posterior or lingual edge there is an enlargement R.G which is the reserve germ for a permanent tooth. The superficial cells of the dentine papilla P are becoming columnar. IV. The inner columnar cells of the enamel germ ( called enamel cells) A have formed a cap of enamel EN, inside which the superficial cells of the papilla, the odontoblasts O, have formed a layer of dentine D. V. Shows a more advances stage still. The deposit of dentine is extending downwards, and enclosing the papilla to form the future pulp, in which a vessel V is seen. Labels: A, inner layer; B, outer layer; C, remains of intermediate cells; D, dentine; D.L, dental lamina; E, epithelium; E.G, enamel germ; EN, enamel; F, dental furrow; L.D, labio-dental furrow; M, connective tissue cells; O, odontoblasts; P, dentine papilla; R.G, reserve germ; V, blood vessels.

Development of a Tooth

Diagram to illustrate the development of a tooth. I. Shows the downgrowth of the dental lamina D.L.…

Incisor tooth of a horse-posterior view. Labels: a, outer layer of enamel; b, inner layer of enamel round the infundibulum; c, dental star; d, the dentine.

Horse Incisor Tooth

Incisor tooth of a horse-posterior view. Labels: a, outer layer of enamel; b, inner layer of enamel…