Oral Physiology M3 - PHYSIOLOGY OF THE TEETH AND ITS SUPPORTING STRUCTURES IN RELATION TO THE PATHOLOGIC PROCESSES OF THE ORAL STRUCTURES

Lesson 1 - Teeth Lesson 2 - Structures Lesson 3 - Pathologic Conditions

Covered with enamel

Covered with enamel

Crown

Crown with/have incisal ridges or edges

Anterior Teeth

Crown with/present cusps

Posterior teeth

Used to punch and cut food material during mastication.

Incisal ridge/edge

Teeth with incisal ridge/edge

Central and Lateral incisors

Used to shear and tear food support the incisors and premolars

Single cusp

Teeth with single cusp

Canines/ Cuspids

Used to grind food support the canines

TWO CUSPS PREMOLARS/BICUSPIDS

used to grind/triturate food

THREE CUSPS AND MORE (MOLARS)

covered with cementum

Root

The length and number of roots depends on the size and function of the teeth. T/F

T

GIVE ALL MONO-ROOTED TEETH

• Incisors

• Canines

• Premolars (Max 2nd; Mandi 1st & 2nd)

GIVE ALL BI-ROOTED TEETH

• Max. 1st PM

• Mandibular molars

GIVE ALL MULTI-ROOTED TEETH

ALL MAXILLARY MOLARS

Positive contact relation mesially and distally of one tooth with another while they are on their respective position in the dental arch importance

PROXIMAL CONTACT AREA (PCA)

2 importance of PCA

1. keep food from packing in between the teeth

2. stabilize the dental arches by the combined anchorage

PCA ASPECT that will demonstrate the relative position of the contact areas cervico-incisally or cervico-occlusally

Labial / Buccal aspects

anterior teeth; proximal contact areas are ___________

not at the same level

Lateral PCA is higher than central. T/F

T

Canine’s PCA is lower than lateral. T/F

F

posterior teeth; PCA are at the _______

Same level

Canine to PM – both PCA is at the same level. T/F

T

PCA ASPECT that will show the relative position of the contact areas labio-lingually or bucco-lingually

INCISAL / OCCLUSAL ASPECTS

They are formed by the proximal surfaces in contact. Are triangularly shaped spaces in between teeth

and normally are filled by the gingival tissue

Interproximal spaces

IPS - There is normally a separation of ________ between the enamel and alveolar bone

1- 1 1⁄2 mm

When two teeth in the same arch are in contact, their curvatures adjacent to the contact areas forms

spillway spaces called embrasures

EMBRASURE

2 kinds of embrasure

1. Labial or Buccal and Lingual Interproximal

2. Incisal or occlusal Interproximal

Its purpose is:

• It makes a spillway for the escape of food during mastication

• It prevents food from being forced through the contact area

Embrasure

Approximately ______ is the normal curvature from the cementoenamel junction (CEJ) to the crest of the contour

0.5 mm

2 Physiologic importance of Cervical Ridge

1. Holds the gingiva under definite tension

2. Protects the gingival margins by deflecting food material away from the margins during mastication

Gingival tissue may be driven apically resulting to gum recession and possible pathologic changes

ABSENCE OR MINIMAL CURVATURE OF CERVICAL RIDGE

• Gingiva is protected too much and loses tissue “tone” under the exaggerated contour

• Food material and debris will be packed around the gingiva

• Stagnation of foreign material leads to chronic inflammation of the gingiva

TOO MUCH CURVATURE OF CERVICAL RIDGE

Cervical ridge curvature that food will just deflect

Normal Curvature

Mesial CEJ is deeper than the Distal CEJ. T/F

T

The curvature of the cervical line (CEJ) of most teeth will be approximately _____ less distally than mesially

1 mm

PDL is ________ attaching the tooth to the alveolar bone

DENSE CONNECTIVE TISSUE

Thickness varies between 0.1 - 0.25 mm

Periodontal Ligament

Functions of PDL

• Supportive and protective

• Formative

• Sensory

• Nutritive

Formative reaction from the PDL could signal the activation of __________________

Osteoblasts, cementoblasts, and fibroblasts

Nutritive due to the presence of blood supply from the branches of the ________________

Alveolar and interradicular arteries

PRINCIPAL PERIODONTAL FIBER GROUPS

1. TRANSSEPTAL

2. ALVEOLAR CREST

3. HORIZONTAL

4. OBLIQUE

5. APICAL

6. INTERRADICULAR

Embedded into the cementum of adjacent teeth and extends interproximally over the alveolar crests

TRANSSEPTAL FIBERS

extends obliquely from the cementum beneath the junctional epithelium to the alveolar crest. From cementum to alveolar crest

ALVEOLAR CREST FIBERS

Surgery involving PDL fibers

CSF (Circumferential Supracrestal Fiberotomy)

extends at right angle to the long axis of the tooth between cementum and alveolar bone

Horizontal fibers

largest group of principal periodontal fibers, extending from the cementum obliquely to the alveolar bone

Oblique fibers

radiates from the apical cementum to the alveolar bone at the base of the socket. Also known as the “fundus”

Apical fibers

courses over the crest of the interradicular septum in the furcations of multirooted teeth

INTERRADICULAR FIBERS

Mineralized connective tissue that covers the roots of teeth

CEMENTUM

secrete cementum to help keep the tooth stable within the socket

Cementocytes

removal of the cementum

Cemtoclasts

Cementum consists of:

• Cementoblasts

• cementoclasts

• cementocytes

ACCORDING TO LOCATION - cementum

■ Radicular Cementum

■ Coronal Cementum

ACCORDING TO CELLULARITY - cementum

■ Cellular Cementum

■ Acellular Cementum

ACCORDING TO PRESENCE OR ABSENCE OF COLLAGEN FIBRILS - cementum

■ Fibrillar Cementum

■ Afibrillar Cementum

covers the coronal half of the root; devoid of cells

ACELLULAR FIBRILLAR CEMENTUM

■ covers the apical half of the root and the furcation of multirooted teeth

■ cementocytes are noted

CELLULAR FIBRILLAR CEMENTUM

extension of enamel beyond the cervical margin

ENAMEL PROJECTIONS

■ cemental dysplasia

■ excess cementum is formed on the root, most commonly affecting the apical third

HYPERCEMENTOSIS

droplets of ectopic enamel occasionally found on the roots of teeth, most commonly in the

bifurcation or trifurcation areas

ENAMEL PEARL

small foci of calcified tissue, not necessarily true cementum, which lie free or attached in the PDL of the lateral and apical root areas; Radiopaque in the x-ray

CEMENTICLES

part of maxilla and mandible that forms and supports the teeth

ALVEOLAR BONE

ALVEOLAR BONE CONSISTS OF:

osteoblasts, osteoclasts, and osteocytes

PARTS OF ALVEOLAR BONE

1. ALVEOLAR BONE PROPER

2. SUPPORTING BONE

consists of thin lamella of bone immediately surrounding the root; radiopaque lamina dura in radiograph

ALVEOLAR BONE PROPER

surrounds the alveolar bone proper and provides additional functional support

SUPPORTING BONE

Consists of vascular connective tissue contained within the rigid dentinal walls

PULP

PULP CONTAINS:

fibroblasts (for collagen formation), odontoblasts, and defensive cells

FUNCTIONS OF PULP:

• FORMATIVE

• NUTRITIVE

• SENSORY

• DEFENSIVE

majority of sensory receptors on the dental nerves are ____________

free nerve endings

DEFENSIVE PULP provides inflammatory and immune response via ________________

• histiocytes/wandering cells,

• undifferentiated mesenchymal cells,

• polymorphonuclear leukocytes,

• lymphocytes,

• plasma cells,

• eosinophils

__________ in cellular components, ________ in the number and quality of blood vessels and nerves, __________ in size and volume of the pulp owing to continued dentin deposition and reparative dentin formation in relation to Pulp response to aging.

DECREASE

Pulpal response to aging

Dentinal Sclerosis

_________ in number and thickness of collagen fibers, ________ of pulp stones and dystrophic mineralizations, in relation to pulp response to aging.

Increase

Part of the oral mucosa that covers the alveolar processes and surrounds the cervical region of the teeth

GINGIVA

3 REGIONS OF GINGIVA

1. MARGINAL GINGIVA / UNATTACHED

2. ATTACHED

3. INTERDENTAL PAPILLA / GINGIVA

Border of the gingiva surrounding the teeth in a collar fashion

MARGINAL GINGIVA

Firm, resilient and tightly bound to the underlying alveolar periosteum

ATTACHED GINGIVA

Occupies the interproximal space between the areas of adjacent tooth contact

INTERPROXIMAL GINGIVA

LAYERS OF GINGIVAL EPITHELIUM (3)

1. ORAL EPITHELIUM

2. SULCULAR EPITHELIUM

3. JUNCTIONAL EPITHELIUM

The outer epithelium that covers the crest and outer surface of the marginal gingiva and the surface of the attached

ORAL EPITHELIUM

WHICH LAYER OF GINGIVAL EPITHELIUM IS THE ONLY KERATINIZED

ORAL EPITHELIUM

Lines the gingival sulcus; A thin layer of non-keratinized squamous epithelium that extends from the coronal limit of the junctional epithelium to the crest of the gingival margin

SULCULAR EPITHELIUM

Comprises a collar-like band of non-keratinized squamous epithelium. The tooth is reinforced by the gingival fibers that brace the marginal gingiva against the tooth surface

JUNCTIONAL EPITHELIUM

GROUPS OF GINGIVAL FIBERS (8)

1. DENTOGINGIVAL

2. DENTOALVEOLAR

3. ALVEOLOGINGIVAL

4. CIRCULAR

5. SEMICIRCULAR

6. TRANSSEPTAL

7. TRANSGINGIVAL

8. INTERGINGIVAL

Embedded into the cementum just beneath the epithelium at the base of the gingival sulcus; The fibers then spread in fan-like fashion into the periosteum, crest of interdental gingiva, and attached gingiva

DENTOGINGIVAL

Fibers extend to the outer surface of the alveolar bone

DENTOALVEOLAR

Fibers extend from the alveolar crest to the lamina propria of free and attached gingiva

ALVEOLOGINGIVAL

Fibers that encircle the tooth in a ring-like fashion

CIRCULAR

Fibers that emanate from the cementum near the CEJ, cross the free gingival margin, and insert into a similar position on the tooth's opposite side

SEMICIRCULAR

Forms horizontal bundles between the cementum of approximating teeth into which they are

embedded; They lie in the area between the epithelium at the base of the gingival sulcus and the crest of the interdental bone

TRANSSEPTAL

Seen in and around the teeth within the attached gingiva

TRANSGINGIVAL

Seen within the attached gingiva adjacent to the basement membrane extending mesiodistally, providing support and contour for the attached gingiva

INTERGINGIVAL

The connective tissue of the gingiva that is densely collagenous

LAMINA PROPRIA

A ____________ subjacent to the epithelium consisting of papillary projections between the epithelial rete pegs

papillary layer

A ______________ connecting with the periosteum of the alveolar bone

reticular layer

Blood supply of Gingiva

• Supraperiosteal arterioles from facial and lingual alveolar bone

• vessels of PDL

• arterioles emerging from crest of interdental septa

Nerve supply of Gingiva

• fibers from PDL

• Labial, buccal, lingual nerve

• Unspecialized nerve-endings, MEISSNER-type, KRAUSE-type specialized nerve endings

Color of gingiva

COLAR PINK

Due to_______________ occurs as a diffuse deep purple discoloration or irregular brown pigmented areas

MELANOCYTES