DENTAL
ANATOMY &
PHYSIOLOGY
INDEX
1. Introduction – oral cavity
2. Functions of oral cavity
3. Teeth introduction
4. Dental Anatomy &
physiology
5. Dentine tissues
6. Periodontal tissues
7. Demineralization &
Remineralization
8. Dentine sensitivity
9. Factors Responsible For
Dental Disease
10. Dental disorders
Oral cavity includes:
Lips
Commissure of lips :
• Where upper & lower lips
meet at corner of mouth.
Vestibule :
• Space bounded by teeth,
gums, Mucosal surface of the
lips & cheeks [on both sides].
Buccal mucosa :
• Inner lining of cheeks
ORAL CAVITY
ORAL CAVITY
 Gingiva (gums)
 Retro molar trigone
• Area just behind back molars in
lower jaw
 Hard palate
• Bony part of roof of mouth
 Soft palate
• fleshy, flexible part at back of
roof of the mouth
 Teeth
 Tongue
 Lower jaw (mandible)
 Upper jaw (maxilla)
Functions Of Oral
Cavity
• Helps in process of digestion
o Receives food, chews & mixes it with saliva.
o Saliva helps in swallowing process.
o Taste buds on tongue provide different sensations of
taste.
• Plays important role in speech.
• Also used for breathing, drinking, facial expressions and social
interactions (such as kissing).
Small calcified, whitish structures in jaws
 Functions: help in tearing scraping &
chewing food
Composed of Hydroxyapatite & Carbonated
hydroxyapatite
Roots of teeth - covered by gums
Humans usually have 20 primary teeth
(deciduous, baby, or milk teeth) and 32
Incisor Canine Premolar Molar
7
Incisors - Cut food
Canines - Shred [scrap or cut] food
Premolars - Chew & grind food
Molars - Grinding food
Mandible
Maxilla Incisors
Canine
Premolars
Molars
 Deciduous teeth : Commonly known as primary teeth /
baby teeth/ temporary teeth /milk teeth.
 Total no of teeth : 20
Normally Adult has 32 teeth
Dental Anatomy & Physiology
Enamel
Alveolar Bone
Pulp
Chamber
 Enamel (hard tissue)
 Dentin (hard tissue)
 Odontoblast Layer
 Pulp Chamber (soft tissue)
 Gingiva (soft tissue)
 Periodontal Membrane (soft
tissue)
 Cementum (hard tissue)
 Alveolar Bone (hard tissue)
 Pulp Canals
 Apical Foramen
The Dental Tissues
Dentin
Odontoblast Layer Gingiva
Periodontal Membrane
Cementum
Pulp Canals
Apical Foramen
11
3 main dental tissues:
 Enamel
 Dentin
 Dental Pulp
Enamel
Dentin
Dental Pulp
12
The Dental Tissues
 Structure
 Highly calcified & hardest tissue in body
 Insensitive—no nerves
 Acid-soluble—demineralizes at pH ≤ 4.5
 Cannot be renewed
 Darkens with age
 Fluoride, calcium phosphate & saliva can
help with remineralization
Dental Tissues:
Enamel
13
Enamel
 Enamel can be lost by :
◦ Physical mechanism
• Abrasion (mechanical wear)
• Attrition (tooth-to-tooth
contact)
• Multifactorial etiology:
Combination of physical &
chemical factors
14
Dental Tissue:
Enamel
Enamel
 Hard tissue, but softer than enamel
 Consist dentinal tubules (fluid inside)
 Does not have nerve supply
 Demineralizes at pH ≤ 4.5
Dental Tissues:
Dentin
15
Dentin
Classification:
 Primary dentin : forms initial shape of tooth.
 Secondary dentin: deposited after formation of primary dentin on all
internal aspects of pulp cavity.
 Tertiary dentin or “reparative dentin”: formed by replacement of
odontoblasts in response to moderate-level irritants e.g. attrition,
abrasion, erosion, trauma, dental caries & certain operative
procedures.
Dental Tissues—Dentin
16
 Innermost part of tooth
 Soft tissue rich with blood
vessels & nerves
 Responsible for nourishing tooth
 Typically sensitive to extreme
thermal stimulation (hot / cold)
Dental Tissue: Dental
Pulp
17
Dental Pulp
 Gingiva
 Periodontal Membrane
 Alveolar Bone
 Cementum
Periodontal
Tissues
Gingiva
Alveolar bone
Cementum
Periodontal Membrane
18
 Part of oral mucosa
 Serves as support structure for
adjacent tissues.
Gingiva
19
Periodontal Tissues:
Gingiva
 Also called as “alveolar
process”.
 Thickened ridge of bone
containing tooth sockets in
mandible & maxilla.
Alveolar bone
20
Periodontal Tissues:
Alveolar Bone
 Soft tissue sheath – acts as cushion
between bony socket & tooth
 Holds tooth in place
 Fibers of periodontal membrane -
embedded within Cementum
Periodontal Membrane
21
Periodontal Tissues:
Periodontal Membrane
 Soft bony tissue
◦ Covers root surface in thin
layer
◦ Assists in tooth support.
◦ Meets enamel in line that
surrounds tooth
That line is called “cemento-
enamel junction”.
Cementum
22
Periodontal Tissues:
Cementum
"Demineralization" – means "dissolution of enamel.“
Substantial number of mineral ions may get removed from
Hydroxyapatite [HAP] latticework without destroying its structural
integrity.
How does Demineralization
happen?
At pH ≤ 4.5, HAP can get
dissolved in process known as
demineralisation.
More the acidic
environment, greater is the
outward flow [loss] of ions.
Demineralization phase if
continues for longer period,
may cause excessive loss of
minerals, leading to loss of
enamel structure.
J Conserv Dent. 2016 Jul-Aug; 19(4): 328–331.
International Journal of Advanced Health Sciences 2015; 1(10): 21-
24
 Process whereby calcium & phosphate ions are supplied to tooth
from external source to promote ion deposition.
J Dent Res. 2010 Nov;89(11):1187-97
Sensitivity
Dentinal hypersensitivity
Short, sharp pain arising from
exposed dentin in response to stimuli
Hot and cold food and drinks, sweet food, acidic
drinks, brushing teeth
J Conserv Dent. 2010 Oct-Dec; 13(4): 218–224
Dental hypersensitivity:
Etiology
Loss of enamel
[wear]
Loss of
Cementum
Loss of gingival
tissue
Exposed
Dentin
Dental
hypersensitivity
Normal Vs. Sensitive teeth
Loss of enamel
[wear]
Loss of gingival
tissue
Loss of
Cementum
Exposed
Dentin
Theories For Dentinal Hypersensitivity
Hydrodynamic theory
widely accepted theory for dentinal
hypersensitivity
Three main mechanisms of dentin sensitivity are
proposed:
A. Direct Innervation (DI) Theory
B. Odontoblast Receptor (OR) Theory
C. Fluid Movement/Hydrodynamic Theory
J Dent (Shiraz). 2013 Sep; 14(3): 136–145.
Exposed dentine with open dentine
tubules
Sensitive dentine
Non-sensitive
dentine
Hydrodynamic theory
J Dent (Shiraz). 2013 Sep; 14(3): 136–145.
External stimulus comes in contact of exposed dentine
Triggers change in flow of dentinal fluid.
Resultant pressure change across dentine activates nerve fibres to
cause immediate pain.
Pain
Hydrodynamic theory
JDent(Shiraz).2013Sep;14(3):136–145.
THANK YOU

Dental anatomy & physiology

  • 1.
  • 2.
    INDEX 1. Introduction –oral cavity 2. Functions of oral cavity 3. Teeth introduction 4. Dental Anatomy & physiology 5. Dentine tissues 6. Periodontal tissues 7. Demineralization & Remineralization 8. Dentine sensitivity 9. Factors Responsible For Dental Disease 10. Dental disorders
  • 3.
    Oral cavity includes: Lips Commissureof lips : • Where upper & lower lips meet at corner of mouth. Vestibule : • Space bounded by teeth, gums, Mucosal surface of the lips & cheeks [on both sides]. Buccal mucosa : • Inner lining of cheeks ORAL CAVITY
  • 4.
    ORAL CAVITY  Gingiva(gums)  Retro molar trigone • Area just behind back molars in lower jaw  Hard palate • Bony part of roof of mouth  Soft palate • fleshy, flexible part at back of roof of the mouth  Teeth  Tongue  Lower jaw (mandible)  Upper jaw (maxilla)
  • 5.
    Functions Of Oral Cavity •Helps in process of digestion o Receives food, chews & mixes it with saliva. o Saliva helps in swallowing process. o Taste buds on tongue provide different sensations of taste. • Plays important role in speech. • Also used for breathing, drinking, facial expressions and social interactions (such as kissing).
  • 6.
    Small calcified, whitishstructures in jaws  Functions: help in tearing scraping & chewing food Composed of Hydroxyapatite & Carbonated hydroxyapatite Roots of teeth - covered by gums Humans usually have 20 primary teeth (deciduous, baby, or milk teeth) and 32
  • 7.
    Incisor Canine PremolarMolar 7 Incisors - Cut food Canines - Shred [scrap or cut] food Premolars - Chew & grind food Molars - Grinding food Mandible Maxilla Incisors Canine Premolars Molars
  • 8.
     Deciduous teeth: Commonly known as primary teeth / baby teeth/ temporary teeth /milk teeth.  Total no of teeth : 20
  • 9.
  • 10.
    Dental Anatomy &Physiology
  • 11.
    Enamel Alveolar Bone Pulp Chamber  Enamel(hard tissue)  Dentin (hard tissue)  Odontoblast Layer  Pulp Chamber (soft tissue)  Gingiva (soft tissue)  Periodontal Membrane (soft tissue)  Cementum (hard tissue)  Alveolar Bone (hard tissue)  Pulp Canals  Apical Foramen The Dental Tissues Dentin Odontoblast Layer Gingiva Periodontal Membrane Cementum Pulp Canals Apical Foramen 11
  • 12.
    3 main dentaltissues:  Enamel  Dentin  Dental Pulp Enamel Dentin Dental Pulp 12 The Dental Tissues
  • 13.
     Structure  Highlycalcified & hardest tissue in body  Insensitive—no nerves  Acid-soluble—demineralizes at pH ≤ 4.5  Cannot be renewed  Darkens with age  Fluoride, calcium phosphate & saliva can help with remineralization Dental Tissues: Enamel 13 Enamel
  • 14.
     Enamel canbe lost by : ◦ Physical mechanism • Abrasion (mechanical wear) • Attrition (tooth-to-tooth contact) • Multifactorial etiology: Combination of physical & chemical factors 14 Dental Tissue: Enamel Enamel
  • 15.
     Hard tissue,but softer than enamel  Consist dentinal tubules (fluid inside)  Does not have nerve supply  Demineralizes at pH ≤ 4.5 Dental Tissues: Dentin 15 Dentin
  • 16.
    Classification:  Primary dentin: forms initial shape of tooth.  Secondary dentin: deposited after formation of primary dentin on all internal aspects of pulp cavity.  Tertiary dentin or “reparative dentin”: formed by replacement of odontoblasts in response to moderate-level irritants e.g. attrition, abrasion, erosion, trauma, dental caries & certain operative procedures. Dental Tissues—Dentin 16
  • 17.
     Innermost partof tooth  Soft tissue rich with blood vessels & nerves  Responsible for nourishing tooth  Typically sensitive to extreme thermal stimulation (hot / cold) Dental Tissue: Dental Pulp 17 Dental Pulp
  • 18.
     Gingiva  PeriodontalMembrane  Alveolar Bone  Cementum Periodontal Tissues Gingiva Alveolar bone Cementum Periodontal Membrane 18
  • 19.
     Part oforal mucosa  Serves as support structure for adjacent tissues. Gingiva 19 Periodontal Tissues: Gingiva
  • 20.
     Also calledas “alveolar process”.  Thickened ridge of bone containing tooth sockets in mandible & maxilla. Alveolar bone 20 Periodontal Tissues: Alveolar Bone
  • 21.
     Soft tissuesheath – acts as cushion between bony socket & tooth  Holds tooth in place  Fibers of periodontal membrane - embedded within Cementum Periodontal Membrane 21 Periodontal Tissues: Periodontal Membrane
  • 22.
     Soft bonytissue ◦ Covers root surface in thin layer ◦ Assists in tooth support. ◦ Meets enamel in line that surrounds tooth That line is called “cemento- enamel junction”. Cementum 22 Periodontal Tissues: Cementum
  • 23.
    "Demineralization" – means"dissolution of enamel.“ Substantial number of mineral ions may get removed from Hydroxyapatite [HAP] latticework without destroying its structural integrity.
  • 24.
    How does Demineralization happen? AtpH ≤ 4.5, HAP can get dissolved in process known as demineralisation. More the acidic environment, greater is the outward flow [loss] of ions. Demineralization phase if continues for longer period, may cause excessive loss of minerals, leading to loss of enamel structure. J Conserv Dent. 2016 Jul-Aug; 19(4): 328–331. International Journal of Advanced Health Sciences 2015; 1(10): 21- 24
  • 25.
     Process wherebycalcium & phosphate ions are supplied to tooth from external source to promote ion deposition. J Dent Res. 2010 Nov;89(11):1187-97
  • 26.
    Sensitivity Dentinal hypersensitivity Short, sharppain arising from exposed dentin in response to stimuli Hot and cold food and drinks, sweet food, acidic drinks, brushing teeth J Conserv Dent. 2010 Oct-Dec; 13(4): 218–224
  • 27.
    Dental hypersensitivity: Etiology Loss ofenamel [wear] Loss of Cementum Loss of gingival tissue Exposed Dentin Dental hypersensitivity
  • 28.
    Normal Vs. Sensitiveteeth Loss of enamel [wear] Loss of gingival tissue Loss of Cementum Exposed Dentin
  • 29.
    Theories For DentinalHypersensitivity Hydrodynamic theory widely accepted theory for dentinal hypersensitivity Three main mechanisms of dentin sensitivity are proposed: A. Direct Innervation (DI) Theory B. Odontoblast Receptor (OR) Theory C. Fluid Movement/Hydrodynamic Theory J Dent (Shiraz). 2013 Sep; 14(3): 136–145.
  • 30.
    Exposed dentine withopen dentine tubules Sensitive dentine Non-sensitive dentine Hydrodynamic theory J Dent (Shiraz). 2013 Sep; 14(3): 136–145.
  • 31.
    External stimulus comesin contact of exposed dentine Triggers change in flow of dentinal fluid. Resultant pressure change across dentine activates nerve fibres to cause immediate pain. Pain Hydrodynamic theory JDent(Shiraz).2013Sep;14(3):136–145.
  • 32.

Editor's Notes

  • #8 Incisors (central and lateral) The incisors are located near the entrance of the oral cavity and function as cutting or shearing instruments for food. From a proximal view, the crowns of these teeth have a triangular shape with a narrow incisal surface, including the incisal edge, and a broad cervical base. The incisors contribute significantly in cutting actions and other functions; esthetics; and phonetics.   Canines The canines possess the longest roots of all teeth and are located at the corners of the dental arch. They function in the seizing, piercing, and tearing of food, as well as in cutting. From a proximal view the crown also has a triangular shape with a thick incisal ridge. The stocky anatomic form of the crown and length of the root are reasons why these teeth are strong, stable abutment teeth for a fixed or removable prosthesis. The canines serve as imortant guides in occlusion because of their anchorage and position in the dental arches.   Premolars The premolars serve a dual role in function: they act like the canines in the tearing of food and are similar to molars in the grinding of food. Whereas the first premolars are angular, with their facial cusps resembling the canines, the lingual cusps of the maxillary premolars and molars have a more rounded anatomic form. The occlusal surfaces present in a series of curves in the form of concavities and convexities that should be maintained throughout life for correct occlusal contacts and function.   Molars The molars are large, multicusped, strongly anchored teeth located nearest the temporomandibular joint (TMJ), which serves as the fulcrum during function. These teeth have a major role in the crushing, grinding, and chewing of food to the smallest dimensions suitable for deglutition. The occlusal surfaces of both premolars and molars act as a myriad of shears that function in the final mastication of food. The premolars and molars are also important in maintaining the vertical dimension of the face.   All definitions from: Sturdevant JR, Lundeen TF, Sluder TB Jr. Clinical significance of dental anatomy, histology, physiology, and occlusion. In: Roberson TM, Heymann HO, Swift EJ Jr, eds. Sturdevant's Art and Science of Operative Dentistry. 4th ed. St. Louis, MO: Mosby; 2002:15-16.    
  • #12 The anatomic tooth crown is the portion of the tooth covered by enamel. The anatomic root is the lower two thirds of a tooth. The roots are normally subgingival, buried in bone, and serve to anchor the tooth in position. The pulp cavity houses the dental pulp, an organ of myelinated and unmyelinated nerves, arteries, veins, lymph channels, connective tissue cells, and various other cells involved in formative or developmental, nutritive, sensory, protective, and defensive or reparative processes.
  • #13 The 4 main dental tissues are: Enamel Dentin Cementum Dental pulp
  • #14 Structure Highly calcified and hardest tissue in the body Crystalline in nature Enamel rods Insensitive—no nerves Acid-soluble—will demineralize at a pH of 5.5 and lower Cannot be renewed Darkens with age as enamel is lost Fluoride and saliva can help with remineralization
  • #15 Softer than enamel Susceptible to tooth wear (physical or chemical) Does not have a nerve supply but can be sensitive Is produced throughout life Three classifications Primary Secondary Tertiary Will demineralize at a pH of 6.5 and lower Primary dentin forms the initial shape of the tooth. It is usually completed 3 years after tooth eruption (for permanent teeth). Secondary dentin is deposited after the formation of the primary dentin. Secondary dentin forms on all internal aspects of the pulp cavity, but in the pulp chamber of multirooted teeth it tends to be thicker on the roof and floor than on the side walls. Tertiary dentin, or “reparative dentin” is formed by replacement odontoblasts in response to moderate-level irritants such as attrition, abrasion, erosion, trauma, moderate-rate dental caries, and some operative procedures. It usually appears as a localized dentin deposit on the wall of the pulp cavity immediately subadjacent to the area of the tooth that has received the injury.
  • #16 Softer than enamel Susceptible to tooth wear (physical or chemical) Does not have a nerve supply but can be sensitive Is produced throughout life Three classifications Primary Secondary Tertiary Will demineralize at a pH of 6.5 and lower Primary dentin forms the initial shape of the tooth. It is usually completed 3 years after tooth eruption (for permanent teeth). Secondary dentin is deposited after the formation of the primary dentin. Secondary dentin forms on all internal aspects of the pulp cavity, but in the pulp chamber of multirooted teeth it tends to be thicker on the roof and floor than on the side walls. Tertiary dentin, or “reparative dentin” is formed by replacement odontoblasts in response to moderate-level irritants such as attrition, abrasion, erosion, trauma, moderate-rate dental caries, and some operative procedures. It usually appears as a localized dentin deposit on the wall of the pulp cavity immediately subadjacent to the area of the tooth that has received the injury.
  • #17 Softer than enamel Susceptible to tooth wear (physical or chemical) Does not have a nerve supply but can be sensitive Is produced throughout life Three classifications Primary Secondary Tertiary Will demineralize at a pH of 6.5 and lower Primary dentin forms the initial shape of the tooth. It is usually completed 3 years after tooth eruption (for permanent teeth). Secondary dentin is deposited after the formation of the primary dentin. Secondary dentin forms on all internal aspects of the pulp cavity, but in the pulp chamber of multirooted teeth it tends to be thicker on the roof and floor than on the side walls. Tertiary dentin, or “reparative dentin” is formed by replacement odontoblasts in response to moderate-level irritants such as attrition, abrasion, erosion, trauma, moderate-rate dental caries, and some operative procedures. It usually appears as a localized dentin deposit on the wall of the pulp cavity immediately subadjacent to the area of the tooth that has received the injury.
  • #18 Dental pulp is: Innermost part of the tooth A soft tissue rich with blood vessels and nerves Responsible for nourishing the tooth The pulp in the crown of the tooth is known as the pulp chamber Pulp canals traverse the root of the tooth Typically sensitive
  • #20 The gingival is commonly divided into free (the unattached portion, forming the wall of the gingival crevice) and attached (the part that is firm and resilient and bound to the underlying cementum and the alveolar bone, thus being immovable).
  • #21 Dental pulp is: Innermost part of the tooth A soft tissue rich with blood vessels and nerves Responsible for nourishing the tooth The pulp in the crown of the tooth is known as the pulp chamber Pulp canals traverse the root of the tooth Typically sensitive
  • #22 Dental pulp is: Innermost part of the tooth A soft tissue rich with blood vessels and nerves Responsible for nourishing the tooth The pulp in the crown of the tooth is known as the pulp chamber Pulp canals traverse the root of the tooth Typically sensitive
  • #27 Thermal – hot and cold drinks and foods,[7] cold air, coolant water jet from a dental instrument. Electrical – electric pulp testers.[8] Mechanical–tactile – dental probe during dental examination,[8] periodontal scaling and root planing,[8] toothbrushing.[7] Osmotic – hypertonic solutions such as sugars.[8] Evaporation – air blast from a dental instrument.[8] Chemical – acids,[8] e.g. dietary, gastric, acid etch during dental treatments
  • #32 Hydrodynamic Theory for sensitive dentine was first proposed by Brannstorm [21]. This theory is the most widely accepted theory for DH. The theory has been proposed based on the movement of the fluid inside the dentinal tubules. The theory claims that tubules are open between dentine surface which is exposed to the environment and pulp [21-22]. It is believed that DH is made as the result of movement of the fluid inside the dentinal tubules, which is further due to the thermal and physical changes, or as the result of formation of osmotic stimuli near the exposed dentine. The movement of fluid stimulates a baroreceptor and leads to neural discharge. The process is called the hydrodynamic theory of pain [3, 14]. This process is similar to activating the neural fibers around the hair by touching or pressing the hair. The movement of fluid can be toward the inside of the pulp or the outside of dentin. Cooling, drying, evaporation, and hypertonic chemical stimuli cause the dentinal fluid to flow away from the dentin-pulp complex and lead to an increase in pain [15]. Heating causes the fluid to flow toward the pulp. About 75% of patients with DH feel pain in response to cold stimuli [1-3]. As it was stated above, the number of tubules in sensitive dentin is eight times more than the number of tubules in non sensitive dentin. Furthermore, tubules of sensitive dentin are wider than those in non sensitive dentin.