This document defines oral anatomy terminology and describes systems for numbering teeth. It defines 73 oral anatomy terms related to tooth structure and surrounding tissues. It describes the universal numbering system that uses Arabic numbers 1-32 to identify permanent teeth and letters A-T to identify primary teeth. Landmark numbers like 8-9 for maxillary central incisors and 24-25 for mandibular central incisors are provided to help remember the system. The document also briefly outlines the ISO and Palmer numbering systems that are less commonly used.

1. ORAL ANATOMY TERMINOLOGY
Define and locate each of the following general anatomical terms:
1. Anterior (ventral) – front
a. The kneecap is located on the anterior side of the leg.
2. Posterior (dorsal) – back
a. The shoulder blades are located on the posterior side of the body.
3. Lateral- away from the midline of the body
a. The little toe is located on the lateral side of the foot.
4. Medial- toward the midline of the body
a. The big toe is located on the medial side of the foot.
5. Superior (cranial)- upper; towards the head of the body
a. The hand is part of a superior extremity.
6. Interior (caudal, tail)- lower, away from the head, toward the tail
a. The foot is part of an inferior extremity.
7. Cross Section- cutting through an object perpendicular to its long axis
8. Longitudinal Section- lengthwise section; cutting trough an object parallel to its long
axis
9. Sagittal- lengthwise plane running from front to back dividing the body or any of its
parts into right and left sides
10. Midsagittal- sagittal plane through the midline of the body dividing the body or any of
its parts into right and left sides.
11. Transverse (horizontal)- crosswise plane that divides the body into upper and lower
parts.
Define the following Oral Anatomy terms:
1. Alveolar Process (bone)- portion of the jaw that supports the teeth
2. Alveolus- bony socket in which the tooth fits
3. Anatomical Crown- the entire crown that is covered by enamel whether the tooth is
erupted or not
4. Anatomical Root- part of the root that is covered by cementum
5. Anterior Teeth- occupy anterior or front of dental arch, from canine to canine
6. Apex- terminal end or tip of root
7. Apical Foramen- opening at or near the apex of a tooth through which the nerve and
blood supply enter the tooth
8. Apices- plural of apex; tooth with bifurcated roots has 2 apices
9. Bifurcation- furcation in teeth with 2 roots
10. Buccal- surface of posterior teeth next to the cheek
11. Canine (cuspid)- holding or grasping teeth; longest teeth in the human dentition and
most stable since they have the longest roots
12. Cementoenamel Junction (CEJ)- junction of the enamel of crown and cementum of the
root; this junction forms the cervical line around the tooth
13. Cementum- bonelike substance that covers the root. Its main function is to provide a
medium for the attachment of the tooth to the alveolar bone.

2. 14. Central Incisor- designed to cut, anterior teeth lateral incisor
15. Clinical Crown- part of the crown that is seen above the gingiva and is exposed to the
oral cavity
16. Clinical Root- part of the tooth that is embedded in the jaw and is not exposed to the
oral cavity
17. Contact Area- area on a proximal surface that touches the adjacent tooth in the same
arch
18. Cusp- pointed projection or mound on a tooth’s crown
19. Cusp Tip- apex or point of each cusp
20. Dental Anatomy- science of the structure of teeth; each tooth has a crown and a root
21. Dental Arch- dentition is divided into 2 arches - upper (maxillary) and lower
(mandibular); teeth in the upper jaw belong to the maxillary arch; teeth in the lower
jaw belong to the mandibular arch
22. Dentin- calcified tissue forming the inside body of the tooth
23. Dentinoenamel Junction (DEJ)- junction of enamel and dentin
24. Dentition- upper and lower teeth collectively
25. Diastema- space between proximal surfaces
26. Diphyodont- produces two sets of teeth- primary & permanent
27. Distal- surface of tooth away from the midline of the dental arch
28. Embrasure- interproximal space occlusal and cervical to the contact area of adjacent
teeth in the same arch
29. Enamel- covers the outer surface of the anatomical crown. It is the most densely
mineralized and hardest tissue in the human body. It is thickest over the tips of the
crown and becomes thinner until it ends at the cervical line.
30. Facial- surfaces next to the face; labial and buccal are considered facial surfaces
31. Fossa- large, round depression
32. Furcation- area or region lying between and at the base of two or more normal
anatomically divided roots
33. Gingiva- part of the gum tissue that immediately surrounds the teeth and alveolar
bone
34. Groove- a thin line-like depression
35. Height of Contour- widest portion of a tooth
36. Heterodont- dentition with teeth of different shapes
37. Homodont- only one type of tooth
38. Incisal- cutting edge or surface of anterior teeth
39. Interdental Papilla- triangular-shaped gingival tissue that fills the interproximal space
40. Interproximal Space- triangular-shaped area cervical to the contact area of two
adjacent teeth
41. Labial- surface of anterior teeth next to the lips
42. Line Angle- junction of 2 tooth surfaces
43. Lingual- surface of teeth facing the tongue
44. Mandible- lower jaw
45. Mandibular- pertaining to the lower jaw

3. 46. Marginal Ridge- elevation that separates the occlusal or lingual surface from a
proximal surface
47. Mastication- act of chewing
48. Maxilla- upper jaw
49. Maxillary- pertaining to the upper jaw
50. Mesial- surface of tooth toward the midline of the dental arch
51. Mixed Dentition- composed of teeth from both the permanent and primary teeth
after they have been exfoliated, i.e., incisors, canines and premolars.
52. Molar- chew and grind up food
53. Nonsuccedaneous Teeth- permanent teeth that do not succeed or replace primary
teeth- molars
54. Occlusal- chewing surface of posterior teeth
55. Palatal- surface of maxillary teeth nearest the hard palate; lingual surface of maxillary
teeth
56. Periodontal Ligament (PDL)- collagen fibers attached to roots and alveolar bone;
serves as the attachment of the tooth to the bone
57. Permanent Dentition- composed of 32 primary teeth; 16 maxillary and 16 mandibular
teeth; fllows primary dentition
58. Pit- an intersection where grooves join or at the end of a groove
59. Point Angle- point at which 3 tooth surfaces meet
60. Polyphyodont- produces many sets of teeth
61. Posterior Teeth- occupy the back part of the mouth
62. Premolar (bicuspid)- aid in holding and grinding food; a cross between a canine and
molar
63. Primary (deciduous) Dentition- dentition that is shed or exfoliated; composed of 20
teeth; 10 maxillary and 10 mandibular teeth; these teeth are lost at the end of a
certain period and are replaced by the permanent dentition.
64. Proximal- surface or side of a tooth that is next to an adjacent tooth; either mesial or
distal
65. Pulp Canals- canals located within the roots of the tooth
66. Pulp Cavity- pulp chamber and pulp canals together; runs the entire length of the
interior of the tooth from the tip of the pulp chamber to the apex of the root
67. Pulp- central core of the tooth that is the nourishing, sensory, and reparative system
of the tooth; it is composed of blood vessels, lymph vessels, connective tissue, and
nervous tissue
68. Pulp Chamber- major portion of the pulp; housed within the coronal potion of the
tooth
69. Quadrant- each arch is further divided into a right and left half; there are 4 quadrants;
2 in the maxilla; 2 in the mandible
70. Ridge- elevation that forms a line on a crown’s surface
71. Succedaneous Teeth- permanent teeth that replace or succeed the primary teeth after
they have been exfoliated- incisors, canines, premolars
72. Teeth- hard structures in the jaw used for the mastication of food
73. Trifurcation- furcation in teeth with 3 roots- maxillary molars

4. Tooth Numbering Systems
To communicate with colleagues and to keep records of clients’ teeth, a coding system for
designating teeth is helpful and widely used. The most common system used in the United
States is the Universal Numbering System.
Arabic numbers one through thirty-two (1-32) are used for permanent teeth and letters A
through T are used for the twenty primary teeth. Assuming the two arch segments form an
elliptical circle, then a diagram can represent a complete dentition, and the pattern for the
number and letter code can be readily seen.
Try to use some key numbers to help you remember these codes. For example, 8 and 9 are the
maxillary central incisors and 24 and 25 are the mandibular central incisors. You should
remember groups of teeth such as 3, 14, 19, 30 representing all of the first molars and 6, 11, 22,
27 representing the canines. Using these landmark numbers will help you to recall the ones in
between.
In the primary dentition, it is easiest to remember the primary second molars, A, J, K, T and the
primary central incisors, E, F, O, P. There are no premolars in this dentition.
You will be tested by two methods:
1. You must provide the correct number or letter.
a. The permanent mandibular left second molar is #_____ (#20)
b. The primary maxillary right canine is ____ (C)
2. The tooth number will be provided, and you must write out the correct tooth
identification.
a. #12 is the ______________________ (permanent maxillary left first
premolar)
b. L is the ________________________ (primary mandibular left first molar)
The correct order for tooth identification is as follows:
DENTITION ARCH SIDE TOOTH
Permanent Maxillary Right Canine
Primary Mandibular Left Lateral Incisor

5. International Standards Organization (ISO) Designation System:
 Almost never used
 Teeth are designated using a 2 digit code
 First digit- indicates the quadrant
 Second digit- indicates the tooth
 Based on FDI system
Palmer Method Designation System:
 Widely used in orthodontics
 Teeth are designated with a right-angle symbol indicating the quads with the tooth
number inside
 Similar to ISO

6. ANATOMICAL IDENTIFICATION

9. PERMANENT DENTITION

10. PRIMARY DENTITION

11. PERMAMENT DENTITION SEXTANTS

13. SURFACES OF THE TEETH

14. DESIGNATION OF LINE ANGLES
DESIGNATION OF CROWN AND ROOT THIRDS

15. TOOTH NUMBERING SYSTEMS