This is dr. Nitin Gupta , mds endodontics in I.T.S dental college muradnagar, ghaziabad. this is a complete seminar on morpholgy.

1. MORPHOLOGY OF
HUMAN PERMANENT
DENTITION AND
ERUPTION SEQUENCE
Presented by:- Dr. Nitin Gupta
Post graduate Student 1st year

2. OBJECTIVE
 Introduction of dental terminology and its application.
 Understanding dental anatomy.
 To study and facilitate communication about various aspects of teeth.

3. CONTENT
 INTRODUCTION
 CLASSIFICATION
 TOOTH STRUCTURE
 DENTAL ANATOMY
TERMINOLOGY
 GEOMETRIC CONFIGURATION
 CONTACT AREAS AND
EMBRASURES
 SHAPE OF TOOTH & CONTACT
AREAS(Different Views)
 TOOTH IDENTIFICATION
SYSTEM
 TOOTH ERUPTION AND ITS
MECHANISM
 PERMANENT TOOTH
MORPHOLOGY & VARIATION
IN TOOTH MORPHOLOGY
 ERUPTION SEQUENCE
 CONCLUSION
 REFERENCES

4. INTRODUCTION
Teeth are the calcified tissues present in oral cavity,
Used in -chewing food, aids in speech, etc.
Dentition refers to set of all teeth in the
upper jaw bone (maxilla)-maxillary teeth
lower jaw bone (mandible)-mandibular teeth.

5. INTRODUCTION
Humans have 2 sets of teeth during a lifetime-
Diphyodonty
(A)Primary/deciduous
dentition- 1st set of teeth.
(B)Permanent/succedaneou
s dentition- 2nd set of teeth.

6. CLASSIFICATION
BY MORPHOLOGY
 HOMODONT DENTITION:- All teeth
have same morphology
 HETRODONT DENTITION:- Teeth
have different morphology.
BY SETS OF TEETH
MONOPHYDONT DENTITION:-
One set of teeth.
DIPHYDONT DENTITION:-
Two sets of teeth.
POLYPHYDONT DENTITION:-
Multiple sets of teeth.

7. DENTAL ANATOMY TERMINOLOGY

8. DENTAL ANATOMY
TERMINOLOGY
 Anterior teeth: Incisors and canines. 12 total (6 per arch).
 Posterior teeth: Premolars and molars. 20 total (10 per
arch).
CROWN TYPES
 Anatomic crown: The portion of the tooth that extends
from the cement enamel junction (CEJ) to the incisall edge
or occlusal surface.
 Clinical crown: The portion of the tooth that extends
incisally or occlusally from the gingival margin (clinically
visible portion of the tooth).

9. DENTAL ANATOMY
TERMINOLOGY
CHEWING SURFACES
 Incisal edge: The chewing surface of
anterior teeth.
 Occlusal surface: The chewing surface of
posterior teeth consisting of cusps,
ridges, and grooves.
 Occlusal table: The occlusal surface
within the cusp and marginal ridges.

10. TOOTH STRUCTURE

11. ENAMEL
The most calcified and brittle substance in
human body.
 Color ranges from yellowish to grayish-white.
 Semi translucent.

12. DENTIN
 An elastic vascular, mineralized tissue that
is harder than the bone but softer than the
enamel.
 Color is generally yellowish.

13. PULP
 The soft connective tissue that supports the
dentin and is contained inside
 The pulp chamber of the tooth.
 Communicates to the periodontal tissues via
the apical foramen and accessory
 Canals.
CLASSIFICATION OF PULP
By location
 Coronal: Found in the pulp horns.
 Radicular: Found in pulp canals.
FUNCTIONS OF PULP
 Formative: Has mesenchymal cells that
ultimately form dentin.
 Nutritive: Nourishes the avascular dentin.
 Sensory: Free nerve endings provide pain
sensation.
 Protective: Produces reparative dentin as
needed.

14. CEMENTUM
An avascular tissue about 10 μm thick that
covers the radicular dentin.
Composition most closely resembles bone.
FUNCTIONS OF CEMENTUM
 Support: Provides attachment for teeth
(Sharpey’s fibers).
 Protection: Helps prevent root resorption
during tooth movement.
 Formative: Continual apical cementum
deposition accounts for continual.
 Eruption: tooth eruption and movement.

15. CEMENTUM MORPHOLOGY AT
CEJ

16. ENAMEL SURFACE JUNCTION
 LINE ANGLE:- Formed by 2
Surface.
 POINT ANGLE:- formed by 3
surface.
Line
angle
Point
angle
Anterior 6 4
Posterior 8 4

17. EMBRASURES
 Contact area:- The location
at which the proximal
surfaces of two adjacent
teeth make contact.
 Embrasure:- A triangular-
shaped space between the
proximal surfaces of
adjacent teeth which
diverges in four directions
from the contact area.
 Buccal
 Lingual
 Occlusal/incisal
 Cervical/gingival :-
(interproximal space): In
health, this space is
completely filled within the

18. DIVISSION OF TEETH

19. CONTACT AREAS(Different views)

20. CONTACT AREAS
 MAXILLARY HEIGHT OF
CONTOUR
 MANDIBULAR HEIGHT OF
CONTOUR

21. CONTACT AREAS
PROXIMAL CONTACTS (FACIAL
VIEW)
 Generally located increasingly more incisally
(occlusally) from the posterior to the anterior.
 The mesial contact is always located more incisally
than the distal.
 Proximal contacts prevent rotation, mesial drift,
and food impaction.
PROXIMAL CONTACTS
(OCCLUSAL VIEW)

22. GEOMATRIC CONFIGURATION

23. GEOMATRIC CONFIGUATION
PROXIMAL SURFACE
SHAPES
 Triangular: All anterior teeth.
 Trapezoidal: All maxillary posterior
teeth.

24. ANATOMIC LANDMARKS ON TEETH WITH
INNERVATIONS

25. ENAMEL SURFACE ELEVATIONS
 Lobe: The primary center of enamel formation in a tooth. In fully formed teeth, lobes are
represented by cusps, mamelons, and cingula, and are separated by developmental
depressions (anterior teeth) or developmental grooves (posterior teeth).
 Mamelon: A round extension of enamel on the incisal edge of all incisors. There are usually
three mamelons per incisor (one for each facial lobe). They are often translucent because of a
lack of underlying dentin. Mamelons are typically worn down by attrition and mastication; thus,
their presence in adults is an indication of malocclusion.
 Cingulum: A bulbous convexity of enamel located on the cervical third of the lingual surface of
all anterior teeth.
 Cusp: A large elevation of enamel located on the occlusal surface of all posterior teeth and the
incisal edge of canines.
 Tubercle: An extra formation of enamel on the crown of a tooth. Often manifests as a
supernumerary cusp, such as the cusp of Carabelli.

26. ENAMEL SURFACE ELEVATIONS
 Ridge: A linear elevation on the enamel surface.
 Marginal ridge: A ridge on all teeth that forms the mesial and distal margins of posterior
occlusal surfaces and anterior lingual surfaces. Center of the facial crown surface. More
prominent in maxillary canines.
 Buccal (cusp) ridge: A ridge only on premolars that runs occlusocervically in the center of the
buccal crown surface. More prominent in first premolars.
 Cervical ridge: A ridge on all primary teeth and permanent molars that runs mesiodistally in the
cervical third of the buccal surface of the crown.
 Oblique ridge: A ridge on all maxillary molars that extends from the ML to DB cusps (it
separates the MB and DL cusps).
 Triangular ridge: A ridge on all posterior teeth that extends from the cusp tip to the central
groove. The ML cusp of all maxillary molars has two triangular ridges.
 Transverse ridge: A ridge on most posterior teeth that runs buccolingually and connects
opposing buccal and lingual triangular ridges. Most common on maxillary premolars and
mandibular molars.

27. ENAMEL SURFACE DEPRESSION
 Sulcus: A V-shaped depression on the occlusal surface
of posterior teeth between ridges and cusps.
 Fossa: An irregularly shaped depression in the enamel
surface.
 Developmental groove: A well-defined, shallow, linear
depression in enamel that separates the cusps, lobes,
and marginal ridges of a tooth.
 Fissure: A narrow crevice at the deepest portion of the
developmental groove in enamel.
 Pit: A small pinpoint concavity at the termination or
junction of developmental grooves.
 Supplemental groove: An irregularly defined, short
groove auxiliary to a developmental groove that does

28. INNERVATION
 All dental and periodontal innervation arises from the
trigeminal nerve CN V).
 The maxillary nerve (V-2) supplies the maxillary teeth.
 The mandibular nerve (V-3) supplies the mandibular
teeth.
Blood Supply
 ARTERIAL SUPPLY
 All dental and periodontal arterial supply arises from the
maxillary artery.
 The arterial supply generally parallels the corresponding
nerves.
 VENOUS RETURN
 All dental and periodontal venous return drains to the
pterygoid plexus of Veins, which eventually forms as the
maxillary vein.

29. TOOTH IDENTIFICATION NUMBER

30.  Tooth is represented by a number 1 – 8
(permanent) or a letter A – E (deciduous).
 Two lines; indicates which quadrant the
tooth belongs to
 A horizontal representing the occlusal
plane and
 A vertical representing the midline
 Examples:
 Maxillary right central incisor 1
 Mandibular left second deciduous molar E
PALMER/ZSIGMONDY NOTATION
SYSTEM

31. UNIVERSAL NUMBERING SYSTEM
 Uppercase letters for deciduous teeth
 Consecutive from A to T
 Following a clockwise order from maxillary right
second molar to mandibular right second molar
 Numbers for permanent teeth
 Consecutive from 1 to 32
 Following a clockwise order from maxillary right
third molar to mandibular right third molar

32. FDI NUMBERING SYSTEM
Each tooth is allocated a two-digit number; the left
designates the quadrant and the right designates the
tooth order
Examples:-
Mandibular right permanent canine- 43
Maxillary left deciduous lateral incisor- 62

33. TOOTH ERUPTION SEQUENCE AND
MECHANISM

35. TOOTH ERUPTIONS
 1. Primary dentition period - In this only deciduous teeth are present, and occurs from
approximately six months to six years of age. It ends with the eruption of the first permanent
tooth, normally the mandibular first molar.
 2. Mixed dentition period - That period during which both deciduous and permanent teeth are
present, and lasts from approximately 6years to 12 years of age.
 3. Permanent dentition period- That period when only permanent teeth are present, and
which begins at approximately twelve years of age and continues through the rest of life.

36. ERUPTIONS
• 6months
• Eruption
of
deciduou
s
mandibul
ar central
incisors
Primary
• 6 yrs
• Eruption of
Permanent
Mand. 1st
molar
Mixed
• 12 yrs
• Exfoliation
Of
deciduous
Maxillary
2nd molar
Permanent

37. THEORIES OF ERUPTION
There are four most accepted theories of eruption, namely:
 Root elongation theory
 Alveolar bone remodelling theory
 PDL (periodontal ligament) traction theory
 Dental follicle theory

38. ROOT ELONGATION THEORY
 Root formation appears to be the cause of
tooth eruption since, it causes an overall
increase in the length of the tooth along
with the crown moving occlusally.
 Some teeth erupt a greater distance than
the total length of their roots, and teeth will
still erupt after the completion of root
formation or when the tissues forming the
root--the apical papilla, Hertwig's epithelial
root sheath, and periapical tissue are
surgically removed.

39. ALVEOLAR BONE REMODELLING
THEORY
 Formation of bone apical to developing
teeth has long been proposed as one
mechanism for eruption.
 It is observed that the alveolar process
forms during tooth development and is
locally deficient in sites where primary
and permanent teeth fail to develop.

40. PDL(periodontal ligament) TRACTION
THEORY
 Formation and renewal of PDL has been
considered a factor in tooth eruption
because of the traction power that
fibroblasts have.
 This force is transmitted to the extracellular
compartment to collagen fibres, which
aligned in an appropriate inclination bring
about root formation, bring about tooth
movement.
 Not accepted because-impacted teeth with
well developed PDL do not erupt.
 Rootless teeth also erupts

41. DENTAL FOLLICLE THEORY
 Reduced enamel epithelium(REE) & follicle
is associated with tooth eruption.
 REE initiates a signalling mechanism that
attracts osteoclasts, also secretes
proteases which breaks connective tissue.
 Dental follicle is necessary to permit bone
remodelling while eruption.

42. CLINICAL CONSIDERATIONS
• Local factors include –
Deciduous teeth with
consequent drifting of opposing
teeth to block the eruptive
pathway.
Severe trauma –
Eruption cyst.
Crowding of teeth in small jaws
–
Third molars and canines are
teeth mostly impacted.
 Systemic Factors
 Nutrition
 Genetic
 Endocrine

43. MORPHOLOGY OF PERMANENT DENTITION

44. TO BE DISCUSS

45. MAXILLARY THIRD MOLAR

46. Maxillary 3rd Molar
DIMENSIONS

48. FACIAL VIEW
 Crown Dimensions
The mesiodistal crown dimension is greater than the occlusocervical crown dimension
 Crown-Root Dimensions
The maxillary third molar has a uniquely small apical-occlusal (crown and root combined) dimension
 Crown Outline Form
The outline form of the crown has been described as trapezoidal
 Facial Cusp Height/Form
The distofacial (distobuccal) cusp is very short and flattened
 Facial Groove Location
The facial groove is closer to the distal surface of the crown, making the mesiofacial cusp larger than
the distofacial cusp
 Mesial Proximal Contact
The area of greatest mesial convexity (mesial proximal contact) has been located in the middle third of
the crown
 Root Length
In the maxillary arch, the third molar has uniquely short roots
 Root Curvature
Most of the roots curve distally in the apical third

49. LINGUAL VIEW
 Mesiolingual Cusp Size
The mesiolingual cusp is usually the largest cusp
 Distolingual Cusp Size/Pressure
The distolingual cusp is very poorly developed or may be entirely missing
 Lingual Root Curvature
The lingual root often has a marked distal inclination

50. MESIAL VIEW
 Crown Dimensions
The faciolingual (buccolingual) crown dimension is greater than the occlusocervical crown
dimension
 Crown Outline Form
The outline form of the crown has been described as trapezoidal
 Facial Height of Contour
The facial height of contour is in the cervical third of the crown
 Lingual Height of Contour
The lingual height of contour is in the middle third of the crown

51. DISTAL VIEW
 Occlusal Surface Visibility
Much of the occlusal surface is visible because of the angulation of the occlusal
surface relative to the long axis of the root
 Facial Surface Visibility
The markedly smaller distofacial cusp permits much of the facial surface to be visible
 Marginal Ridge Location
The distal marginal ridge is located farther apically than the mesial marginal ridge

52. OCCLUSAL VIEW
 Mesial Crown Dimension
The faciolingual dimension of the mesial half of the crown is considerably larger than the distal
half
 Crown Outline Form
The predominant occlusal outline form is “heart-shaped”
 Mesial Proximal Contact
The mesial proximal contact has been located facial to the faciolingual center of the crown
 Lingual Surface Form
The form of the lingual aspect of the crown is semicircular
 Cusps
There are 3 functioning cusps on the typical third molar: two facial and one lingual cusp
 Oblique Ridge
The oblique ridge is poorly developed and often absent
 Supplemental Grooves

53. MANDIBULAR THIRD MOLAR

54. DIMENSIONS

56. Facial View
 Crown Dimensions
The mesiodistal crown dimension is greater than the occlusocervical crown dimension
 Occlusocervical Crown Dimension
From a facial view, the distal half of the crown has a noticeably shorter than the mesial half
 Mesiofacial Cusp
The mesiofacial cusp is often the widest and tallest of the facial cusps
 Mesial Proximal Contact
The mesial proximal contact has been located at the junction of the occlusal and middle thirds
 Root Length
The root length is only about half again as long as the occlusocervical crown dimension
 Root Trunk
The root trunk is long
 Root Proximity
The roots are often fused together and if separate, the root trunk is long and the root apices are usually
pointed

57. LINGUAL VIEW
 Cusp Size
The mesiolingual cusp is the largest of all the cusps
 Cusp Form
The lingual cusps are rounded

58. MESIAL VIEW
 Crown Dimensions
The faciolingual (buccolingual) crown dimension is greater than the occlusocervical crown
dimension
 Cusp Proximity
The faciolingual distance between the cusp tips is reduced
 Facial Crown Form
The facial surface is very convex and the tooth has a bulbous form
 Mesial Proximal Contact
The mesial proximal contact has been located one third of the distance between the cusp
tip and the cervical line
 Mesial Root
The mesial root is broad faciolingually but short

59. DISTAL VIEW
 Cervical Crown Form
The contour of the cervical crown surface has been described as flat or slightly
convex
 Distal Root
The distal root is narrower faciolingually and shorter than the mesial root

60. OCCLUSAL VIEW
 Crown Dimensions
The mesiodistal crown dimension is greater than the faciolingual crown dimension
 Faciolingual Dimension
The mesial aspect of the crown is much wider faciolingually than the distal half
 Crown Outline Form
The occlusal outline form is often ovoid
 Crown Convergence
The crown tapers from mesial to distal but only slightly from facial to lingual
 Number of Cusps
Third molars often have 4 cusps (mesiofacial, distofacial, mesiolingual, and distolingual)
 Marginal Ridge Form
The mesial and distal marginal ridges are highly convex arcs
 Pit-Groove Form
The pit-groove pattern is highly irregular
The occlusal surface is quite “wrinkled” due to numerous supplemental grooves and ridges

61. PERMANENT AND DECIDOUS
TEETH
 Lighter in color.
 Pulp cavities are large
 Crown is more bulbous and constricted.
 Crown is smoother.
 Anterior teeth are wider M-D & shorter Insicocervically.
 Primary molars are shorter & narrower M-D at cervical 3rd.
 Root tapers more rapidly.
 Root are long 7 slender
 Root trunk is shorter.
 Enamel stops abruptly at CEJ.
 Enamel is thinner

62. DENTAL ANATOMY FACTS
 The primary second molar generally exhibits cusp of Carabelli
 Mandibular central incisors and Maxillary third molars generally occlude with only
one opposing tooth..
 The tooth with the longest root is the maxillary canine.
 Maxillary incisors are the only anterior teeth that are wider mesio-distally than facio-
lingually
 Mandibular Molars are the only posterior teeth that are wider mesio-distally than
facio-lingually
 The MAX canine is the only tooth that has potentional of contacting both anterior
and posterior teeth
 There are a total of 12 teeth in the permanent dentition that normally have
cingulums
 Maxillary lateral incisors have the most distinct and deepest lingual fossa’s of all
anterior teeth.
 The DL groove of a MAX lateral incisor is an anatomical feature that complicates root

63.  The softest dental tissue is cementum. The hardest dental tissue is enamel
 The maxillary 1st premolar has a mesial concavity that makes it difficult to adapt a
matrix band
 The largest root of the maxillary molar is the palatal. The smallest root of the
maxillary molar is the distofacial
 The Mandibular 1st molar has the greatest m-d diameter of all molars
 A key feature that differentiates a mandibular1st & 2nd molar is the number of
developmental grooves
 Another feature is the number of cusps
 The facial cusp of the maxillary 1st premolar is offset to the distal
 The distolingual cusp of maxillary molar is the only one that is not part of the molar
cusp triangle
 Mesiolingual groove is an identifying characteristic for the mandibular 1st premolar

64. CONCLUSION
 Exact tooth contours can only be reproduced in a restoration when we are clear with the
anatomy of that particular tooth.
 Studying the morphology of the teeth helps us to understand the relationship of teeth to one
another, to differentiate each type of tooth, define restoration contours and visualize the
crown contours in order to adapt the instruments properly and replicate the morphology.
 Thus if we are able to reproduce the exact contours of the tooth in our restoration , we
provide the patient with a harmonious occlusion and in turn healthy and physiologic
stomatognathic system.

65. REFERENCE
 Ash MM, Nelson S. Wheeler’s Dental Anatomy, Physiology and Occlusion.8th ed.
Saunders; 2003.
 Woelfel JB, Scheid RC. Dental anatomy : its relevance to dentistry. 7th ed. Lippincott
Williams and Wilkins; 2007.
 Neville B, Damm DD, Allen CM, Bouquot J. Oral and maxillofacial pathology. 3rd ed.
Elsevier; 2009.
 Ten Cate AR, Copeland E. Oral Histology.7th ed. Mosby; 2008.