secretions of the oral cavity: saliva

SALIVA

> lubricates & protects

the structure of the

mouth.

> influences the nature

of oral flora & chemical

composition of teeth.

> it plays a major role in the

maintenance of health & in the

production of disease by permitting or

inhibiting the formation of:

- plaque

- calculus

- proliferation of selected

microorganisms.

> It contains:

a. Immunoglobulins

b. WBC

c. Lipids

d. Electrolytes

e. Protein

Major Salivary Glands:

- produces 95% of the total salivary flow

1. Parotid

2. Submandibular

3. Sublingual

1. Parotid Gland

- biggest, pyramidal in shape

- literally next or anterior to the ear

- opens to the STENSEN’S duct

( opposite the maxillary 2nd molar)

- produces 60-65% of the total salivary flow

2. Submandibular Gland

- irregular, walnut in shape

- lies posteriorly to the floor of the mouth or at the angle of the mandible

- opens to the WHARTON’S duct

(summit of the sublingual papilla at the side of the frenulum of the tongue)

- produces 20-30% of the total salivary flow

3. Sublingual Gland

- smallest, almond in shape

- lies immediately beneath the oral mucosal lining on the anterior portion of the floor of the mouth

- opens to the BARTHOLIN’S duct

(surface of the sublingual fold on either side of the tongue)

- produces 2-5% of the total

salivary flow

Minor Salivary Glands:

- produces 5% of the total salivary flow

1. Minor sublingual

2. Labial

3. Buccal

4. Glossopalatine

5. Palatine

6. Lingual

> Secretion is primarily by

unconditioned reflex associated with

eating & masticatory proprioceptors of

the periodontal ligament & muscles of

mastication.

> 1,000-1,500 ml is the total salivary

fluid produced during a 24-hour

period. (1 cc/min)

Factors Affecting Salivary Secretion:

1. Pharmacologic agents

2. Psychological

3. Size of gland

4. Interference with taste perception

5. Age changes

6. Systemic diseases

7. Disease of the salivary gland

8. Irradiation of glands.

Most important attribute of salivary

secretions:

Protective in nature – helps maintain

integrity of teeth, tongue & mucous

membrane of oral and pharyngeal

areas.

Role in Oral Health:

1. Lubrication & Protection

- glycoproteins & mucoids produced

by the salivary glands forms a

protective covering for the mucous

membrane against irritants.

2. Buffering action

- because of its bicarbonate,

phosphate & amphoteric proteins.

- bacteria require specific pH

condition.

3. Maintenance of tooth integrity

because it:

a. Provides minerals for

posteruptive maturation.

b. Provides ions to counteract tooth

dissolution.

c. Forms a film of glycoprotein that

may act as a diffusion barrier,

to prevent loss of tooth mineral.

4. Antibacterial activity against

bacteria & viral invasion.

- Lysozyme, IgA, Sialoperoxidase

thiocynate & Lactoferin

> Saliva plays a role in the formation

of plaque & calculus and is therefore

intimately related to caries and

periodontal disease.

> Salivary glycoprotein + precipitation

+ pellicle + microorganisms overgrow

+ plaque + mineralization + calculus.

Functions of Saliva: (Lavelle)

1. Digestive Function

- amylase as main digestive enzyme

2. Excretory Function

- saliva provides as important

excretory route for blood components

3. Solvent Function

- by facilitating digestion

- dissolution of foodstuff (one of the

major salivary function)

4. Protective Function

- protects oral tissues from dehydration

- mechanical food & microbial debris

lavage

Process of Secretion: (Ferguson)

> Stimuli to Digestive Organ has

three phases:

1. Cephalic – conditioned stimuli:

a. Psychological Phase

b. Visual Phase

c. Olfactory Phase

a. Psychological phase

> “the thought of food

b. Visual phase

> ”the sight of food”

c. Olfactory phase

> “the smell of food”

2. Intraorgan – within organ stimuli

(most important for salivary

secretion)

a. Mechanical stimuli – touch &

pressure on oral structures and

movements of masticatory muscles

and mandible

b. Chemical stimuli – substances that

stimulate taste receptors

3. Interorgan – stimulatory effect on

secretion from irritation to the

esophagus

e.g. vomiting reflex

Role in Oral Health:

1. Pellicle & plaque deposition

2. Plaque mineralization &

calculus formation

3. Dental caries

PELLICLE

- thin, cellular &

essentially bacteria

free covering of the

tooth which consist of

various glycoprotein

derived from the

mucous salivary

gland.

- thin deposit may form shortly after eruption on the exposed surface of the teeth.

- reformed within minutes after exposure of pumice-polished teeth to saliva.

- due to rapid formation, it precedes the first stage in plaque formation.

PLAQUE

- localized concentration of microorganism on the tooth surface.

- accretion of necrotic debris, foodstuff substances & salivary glycoproteins.

- contains mono & oligosaccharides

that serve as substrates for microbial

growth.

- Streptococcus mutans is the

predominant organism that

enzymatically degrade plaque.

CALCULAR DEPOSIT

- grainy in nature & act as mechanical irritant.

- by product of calcification of organic products & microorganisms.

- calcified bacterial plaque

- organic components consist mainly

of Calcium & Phosphate.

- Types of Calculus:

a. Supragingival

- creamy white or

yellowish in color

- hard in consistency

- most abundantly

seen opposite the

opening of the major

salivary glands

b. Subgingival

- dark brown to black

due to blood pigments

- hard to very hard in

consistency

- found in the

periodontal pockets of

any tooth.

DENTAL CARIES

- is a microbial

disease of the calcified

tissues of the teeth,

characterized by

demineralization of the

inorganic portion &

destruction of the

organic substance of

the tooth.

- Five general ways by which saliva

can affect caries:

a. to mechanically cleanse & thus

lessen plaque accumulation.

b. to reduce enamel solubility by

plaque modification through calcium,

phosphate & fluoride.

c. buffer & neutralize the acids either

produce cariogen or introduced

directly through diet.

d. direct anti-bacterial activity.

e. by aggregation or clumping

bacteria & reducing adherence to

teeth surfaces.

GINGIVAL FLUIDS

- Sulcular fluid

- fluid found in the gingival sulcus

which seeps through the thin sulcular

epithelium.

Have a blessed day!!!