Oral Pathology & Microbiology

lecture (3)

Prepared by:

Dr. Enas Hawari.

Immune system

• Immune system:

Is responsible for providing resistance to

communicable diseases.

• Communicable disease:

Is caused by an infection that can be

spread from person to person or through

contact with body fluids.

• Immunity allows the body to resist

disease and prevents foreign bodies

from causing infection.

• Immunity is classified into:

Naturally acquired immunity.

Artificially acquired immunity.

Naturally acquired immunity

• Occurs when a person has previously

contracted a disease and recovered.

• Two types of naturally acquired immunity:

Active immunity.

Passive immunity.

• Active immunity:

Occurs when the body was fighting the

invading pathogen, it formed antibodies

that provide future resistance against

that particular pathogen.

It is called active because the body of the

host is actively involved in the process.

• Passive immunity:

Occurs during pregnancy when the

fetus receives antibodies from the

mother placenta.

Also occurs when the mother

breastfeeds the infant.

It is called passive cause the antibodies

are acquired from an outside source.

Artificially acquired immunity

• When the human body has not been exposed

to a disease, it has not developed antibodies

and is completely defenseless against the

disease.

• Antibodies can be introduced into the body

artificially by immunization or vaccination.

• A vaccine that contains a weakened

disease-causing organisms is injected

into the body.

• Harmful characteristic of the disease are

eliminated from the vaccine to make them

less likely to cause disease.

• The body then forms antibodies in

response to the vaccine, resulting in

artificially acquired immunity.

ORAL PATHOLOGY

Oral pathology

• Is the study of disease in the oral cavity.

• Only a dentist or a physician may diagnose

disease conditions.

• It is important for the dental assistant to be

able to recognize the difference between

normal and abnormal conditions that appear

in the mouth.

• Before you can recognize abnormal

conditions in the mouth, you must have a

solid understanding of the appearance of

the normal tissue.

• A dental assistant should understand the

terms used to describe pathologic

conditions, so that you can communicate

effectively with other professionals.

Making a diagnosis

• Making a diagnosis is much like putting a

puzzle together – many pieces are

necessary.

• To make an accurate diagnosis, the dentist

must rely on a variety of types of

information.

• One piece of information alone is not

enough to make a diagnosis.

• Eight sources of information can be used

to make a final diagnosis.

• These includes:

Historical.

Clinical.

Radiographic.

Microscopic.

Laboratory.

Therapeutic.

Surgical.

Differential findings.

Historical diagnosis

Personal history

Family history.

Medical history.

Dental history.

History of a lesion.

• Family history is important because of

the genetic disorders.

• Medical history can provide

information about medication the

patient may be taking that could have

an effect on the oral tissue.

Clinical diagnosis

• Is based on the clinical appearance of the

lesion, including the:

Color.

Size.

Shape.

Location.

Radiographic diagnosis

• Radiographs are excellent in providing

information about:

Periapical pathology.

Internal resorption.

Impacted teeth.

Microscopic diagnosis

• When a suspicious lesion is present,

tissue is removed from the lesion and is

sent to a pathology laboratory, this is

called (biopsy).

• This procedure is very often used to

make the final diagnosis.

Laboratory diagnosis

• Blood chemistries and other laboratory

tests, including urinalysis, can provide

information that leads to a diagnosis.

• Cultures done in the laboratory can be

used to diagnose types of oral infection.

Therapeutic diagnosis

• Is made by providing a treatment and

seeing how the condition responds.

Surgical diagnosis

• A diagnosis made on the basis of findings

from a surgical procedure.

• Surgically open the area and inspect it if it

needs a further treatment.

Differential diagnosis

• When two or more possible causes of a

condition are identified, a differential

diagnosis must be made.

• The dentist will determine which tests or

procedures should be done to rule out the

incorrect cause and make a final diagnosis.

Thank you