1. Tooth Morphology (the study of the form of teeth)
Structure of teeth.
Supporting structures.
Deciduous tooth morphology.
Secondary tooth morphology

2. Teeth General arrangement of teeth is called the dentition
Primary dentition
Contains the deciduous teeth
Secondary dentition
Contains the permanent teeth
Mixed dentition
Contains some deciduous and some permanent teeth
Mixed dentition sometimes called ugly ducking stage

3. Maxillary teeth Supported by the maxillary bone
Belong to the maxillary arch
What is the bone called that supports the teeth?
What is special about it?
Figure courtesy Hu-Friedy

4. Mandibular teeth Supported by the mandibular bone
Belong to the mandibular arch
Give me the names of parts of the mandible?
Ramus
Mandibular body
Angle of the mandile
Coronoid process
Condylar process
Give me the names of the 2 foramen in the mandible
Mental
Mandibular
Figure courtesy Hu-Friedy

5. Each arch is divided into a right and left quadrant
Figure courtesy Hu-Friedy

6. Types of teeth Incisors Canines Molars Premolars Anterior teeth
Posterior teeth

7. Incisors Designed to bite or cut food
The biting surface is called the incisal edge.
Central incisor larger than lateral incisor.
Flattened crown with one root.
Upper central incisor is largest of all incisors.
Figure courtesy Hu-Friedy

8. Canines Designed to cut and tear food
Upper canines larger than lowers.
Large conical crown with pointed incisal edge and one long root.
Upper canines have longest of all roots.
Canines known as eye teeth

9. Premolars Used for tearing and chewing food
All have two cusps, equal size in uppers, smaller lingual cusp in lowers.
Upper first premolar has two roots (buccal and palatal), all others have one root.
Upper premolars 2 roots

10. Molars All have large occlusal surface for grinding and chewing food.
All upper molars have three roots (palatal, mesiobuccal and distobuccal)
All lower molars have two roots (mesial and distal).
Upper first molar has five cusps, fifth one called ‘cusp of carabelli’.
Lower first molar has five cusps, three buccal and two lingual.
All other molars have four cusps.
Roots in third molars vary in number, uppers are often fused together.
Figure courtesy Hu-Friedy

11. Occlusion
In a normal mouth all incisal edges and cusps of upper and lower teeth interlock to give a stable bite (occlusion).
The upper arch is usually wider so that the lower teeth bite into the middle of the upper teeth, or onto the cingulum of the incisors and canines.

12. Parts of the teeth Each tooth consists of a crown and root
The crown is covered by enamel
The root is covered by cementum
The crown and root are joined at the cementenamel junction
The cervical line separates the crown and root

13. Enamel Hardest tissue in the body Covers the crown
Thickest over the tips of the crown
Thinnest where crown meets the root
Colour is determined by thickness
Figure courtesy Hu-Friedy

14. Enamel It is made up of 96% inorganic crystals arranged as prisms
Main mineral crystals are hydroxyapatite.
Junction where enamel meets dentine is called the amelodentinal junction.
Contains no nerves or blood vessels and therefore cannot experience sensitivity.
Non-living tissue which cannot grow or repair itself, but can remineralise after acid attack.
Can exchange minerals, especially fluoride, to form fluorapatite crystal which make the enamel surface harder still and more resistant to acid attack.

15. Dentine Forms the bulk of the crown and root of the teeth
Covered by enamel in the crown
Covered by cementum in the root
Living tissue
Receives nutrition from dentinal tubules running from the pulp
Tubules are involved with toothache
Figure courtesy Hu-Friedy

16. Dentine It is up to 80% inorganic.
It is composed of hollow tubules containing fibrils, which are sensory endings from the cells forming the dentine.
It is therefore a living tissue, and can transmit sensitivity.
It is formed by ondontoblast cells, which lie at the edge of the pulp chamber.
It can repair itself by producing secondary dentine.
Secondary dentine also forms as part of the natural ageing process.
Caries progresses rapidly through dentine because of its hollow nature.

17. Cementum The cementum is the layer covering dentine of the root.
It normally lies beneath the gingiva.
It allows attachment of the tooth to the supporting structure of the periodontal ligament.
Calcium Hydroxyapatite
Similar chemically to bone
Figure courtesy Hu-Friedy

18. Pulp Chamber Pulp Canals
Pulp is the soft tissue within the tooth structure.
Surrounded by dentine
Consists of connective tissue, blood vessels and nerves
Odontoblasts present on the wall of the pulp chamber
Figure courtesy Hu-Friedy

19. Pulp
It allows the tooth to feel hot, cold, touch, pain by stimulation of fibrils in dentine.
Vessels enter the tooth through the apical foramen, at the end of each root apex.
These tissues are enclosed within the pulp chamber of the tooth.
Chamber is lined by ondontoblast cells.
Gradual formation of secondary dentine with age causes pulp chamber to decrease in size and become narrower.

20. Support and attach the teeth to their bony sockets
Periodontal tissues
Support and attach the teeth to their bony sockets

21. Attachment tissues Periodontal ligament Cementum Alveolar bone
Known as peridontium
4 parts
Tooth
Alveolar bone
Periodontal ligament
Cementum
Alveolar bone
Diagram courtesy Oral-B

22. Periodontal Ligament
This is a specialised fibrous tissue which attaches the teeth to the alveolar bone and surrounding tissues.
Fibres are made up of protein called collagen.
Acts as a shock absorber when tooth undergoes normal chewing movements, so that the tooth can bounce a little in its socket and not fracture.
Destruction of periodontal ligament occurs during periodontal disease.

23. Alveolar bone
The bony extensions of the maxilla and mandible, where the teeth are formed and from where they erupt into the mouth.
Special bone found only in the jaws.
Sole purpose is to support the teeth during their lifetime.
When teeth are extracted, alveolar bone gradually resorbs away.
Outer layer is hard compact bone, with the surface being called the lamina dura.
Inner layer is cancellous bone, sponge like in appearance to allow blood vessels and nerves to run through.
Destruction of the alveolar bone can occur during periodontal disease.

24. Cementum The cementum is the layer covering dentine of the root.
It normally lies beneath the gingivae.
It allows attachment of the tooth to the supporting structure of the periodontal ligament.

25. Gingivae This is the correct term for the gums.
In health they are light pink in colour with a stippled (orange peel) surface.
Form a 2mm crevice (gingival crevice) around the necks of each tooth, above periodontal ligament.
Gingivitis occurs when this area becomes inflamed.
Inflamed gingivae are red and shiny, with a swollen appearance.

27. EXERCISE

28. Enamel
Dentine
Pulp
Cementum
Periodontal ligament
Lamina Dura (Compact bone)
Cancellous Bone (spongy bone)

29. Eruption

30. Eruption Two sets of teeth develop in a person’s lifetime
The deciduous dentition contains 20 teeth
The permanent dentition contains 32 teeth
And for a period of time a child will have a mixed dentition
Containing some deciduous teeth and some permanent teeth

31. Deciduous dentition
The first teeth to appear are the deciduous incisor teeth at about 6 months
The last teeth to appear are the deciduous second molars at 2 ½ years

32. Deciduous dentition
Figure courtesy Hu-Friedy

33. Deciduous dentition eruption ages
Tooth Eruption age
Central incisors to 8 months
Lateral incisors to 9 months
First molars to 16 months
Canines to 21 months
Second molars to 30 months
a-6 months
b- 8 months
c- 18 months
d- 12 months
e- 24 months

34. Deciduous Teeth
Deciduous teeth in general resemble their corresponding permanent teeth but there are some important differences.
Deciduous teeth are much smaller.
There is adequate space so crowding is uncommon.
Deciduous crowns are whiter.
Pulp chambers of deciduous teeth are relatively larger, their enamel is much thinner.

35. Deciduous Teeth
Deciduous incisors and canines are smaller versions of their permanent successors.
Deciduous molars have the same number of roots as permanent molars but differ in other respects.

36. Deciduous Teeth The crowns of deciduous molars are more bulbous.
To provide space for the developing premolar, the roots of deciduous molars are more divergent than those of permanent molars.
Deciduous 2nd molars resemble miniature 1st permanent molars; but the shape of deciduous 1st molars is much less typical, having a pronounced mesio-buccal bulge.

37. Permanent dentition The permanent teeth replace the deciduous teeth
The first permanent teeth to appear are the mandibular first molars
These teeth erupt behind the deciduous second molars
The next permanent teeth to erupt are the central and lateral incisors

38. Permanent dentition
Figure courtesy Hu-Friedy

39. Permanent dentition eruption ages
Tooth Eruption age
First molars to 7 years
Central incisors
6 to 8 years
Lateral incisors
7- 9 years
Canines
9 to 11 years
First premolars
10 to 12 years
Second premolars
Second molars
12 to 13 years
Third molars to 22 years
These are approx ages
An easy way to work out eruption dates
Lowers Uppers
1-7
2-8
6-6
7-12
8-18

40. Exercise

41. What Is the Approximate Age of These Patients?

42. 12 years
All permanent teeth erupted except the third molars

43. 8-10 years
Canines not quite erupted
No premolars yet
7’s not in
Lower right e present but you can see roots starting to resorb.

44. 7-8 years
6’s erupted
Central’s and laterals erupted
e’s still present

45. CHARTING

46. Tooth surfaces-posterior teeth
Mesial – nearest the midline
Distal – furthest from the midline
Lingual - facing the tongue
Buccal – facing the cheek
Occlusal – chewing surface
Figure courtesy Hu-Friedy

47. Tooth surfaces-anterior teeth
Labial – facing the lip
Mesial – nearest the midline
Distal – furthest from the midline
Lingual - facing the tongue
Incisal edge – biting surface of anterior teeth
Figure courtesy Hu-Friedy

48. There is a convention for naming the teeth which must be followed
Tooth identification
There is a convention for naming the teeth which must be followed

49. The tooth is identified by
The dentition – permanent or deciduous
The arch – maxillary or mandibular
The quadrant – right or left side of the mouth
The tooth type – incisor, canine, premolar or molar

50. EXERCISE

52. Palmer notation Permanent teeth
Figure courtesy Hu-Friedy

53. Examples of palmer notation
Palmer notation Tooth description
Permanent maxillary right second premolar
Permanent maxillary left third molar
Permanent mandibular left lateral incisor
Permanent mandibular right canine
Difficult to recreate on computer so sometime UR UL LL and LR use to define quadrant

54. Palmer notation system Deciduous teeth
Assigns a letter to the deciduous tooth depending on its position relative to the midline
Central incisors are closest to the midline and are given the letter A
The second molars are furthest and are given the letter E

55. Palmer notation Identification Deciduous tooth
Deciduous tooth Symbol assigned
Central incisor A
Lateral incisor B
Canine C
First molar D
Second molar E

56. Palmer notation Deciduous teeth
Figure courtesy Hu-Friedy

57. Palmer notation Deciduous teeth
Palmer Notation Tooth description
Deciduous maxillary right second
molar
Deciduous maxillary left first molar
Deciduous mandibular left lateral
incisor
Deciduous mandibular right canine

58. EXERCISE
Palmers charting

60. FDI notation system – Permanent teeth
Uses a two-digit number to identify each tooth
The first digit identifies the quadrant
The permanent quadrants are numbered from 1 through to 4
The second digit identifies the tooth
The permanent teeth are numbered from 1 through to 8

61. FDI- Identification Permanent tooth
Permanent tooth Number assigned
Central incisor
Lateral incisor
Canine
First premolar
Second premolar
First molar
Second molar
Third molar

62. FDI notation system Permanent teeth
Figure courtesy Hu-Friedy

63. Examples of FDI notation
Notation Tooth description
Permanent maxillary right central incisor
Permanent maxillary right first molar
Permanent maxillary left canine
Permanent maxillary left third molar
Permanent mandibular left first premolar
Permanent mandibular left second molar
Permanent mandibular right lateral incisor
Permanent mandibular right second permolar

64. FDI notation system Deciduous teeth
Uses a two-digit number to identify each tooth
The first digit identifies the quadrant
The deciduous quadrants are numbered from
5 through to 8
The second digit identifies the tooth
The deciduous teeth are numbered from
1 through to 5

65. FDI Identification Deciduous tooth
Deciduous tooth Number Assigned
Central incisor
Lateral incisor
Canine
First molar
Second molar
Not letters but numbers
1-5

66. FDI notation system Deciduous teeth
Figure courtesy Hu-Friedy

67. Examples of FDI notation
Notation Tooth description
Deciduous maxillary right central incisor
Deciduous maxillary right first molar
Deciduous maxillary left canine
Deciduous maxillary left second molar
Deciduous mandibular left first molar
Deciduous mandibular left second molar
Deciduous mandibular right lateral incisor
Deciduous mandibular right central incisor

68. EXCERCISE