This document discusses the principles of diagnosis in dentistry and oral medicine. It covers taking a thorough patient history, performing extraoral and intraoral examinations, considering relevant medical and dental histories, and ordering appropriate diagnostic tests and investigations. The key steps in diagnosis include obtaining a detailed history, conducting a physical examination of the head and neck both extraorally and intraorally, and ordering diagnostic tests such as radiographs, biopsies, or blood tests when indicated based on the history and examination findings. Special attention is paid to examining lymph nodes, salivary glands, teeth, and soft tissues during the intraoral examination.

1. ‫واالسنان‬ ‫الفم‬ ‫وجراحة‬ ‫لطب‬ ‫التخصصي‬ ‫المركز‬
‫المثنى‬ ‫في‬
‫اعداد‬
‫د‬.‫شوكت‬ ‫عمار‬
‫باشراف‬
‫الدكتور‬‫االختصاص‬
‫د‬.‫حسن‬ ‫محمد‬

2. Principles of
diagnosis

3. introduction
This is series of steps that clinicians take to arrive at a
diagnosis.
Diagnosis is defined as the recognition of the disease, naming
the disease as per agreed criteria.
In other words, diagnosis would mean recognizing the disease
and naming it.

4. Table 1. Principles of diagnosis
A. A detailed history
B. Clinical examination
Extraoral
Intraoral
C. Special investigations (as appropriate)
Radiography or other imaging techniques
Biobsy for histopathology (including immunofluorescence,
immunocytochemistry, electron microscopy, molecular biological tests)
Specimen for microbial culture
Haematological or biochemical test.

5. Taking a history
History-taking needs to be tailored to suit the individual patient but it is sometimes
difficult to get a clear idea of the complaint. Many patients are nervous, some are
inarticulate, others are confused.
Initial questions should allow patients to speak at some length and to gain
confidence.
It is usually best to start with an 'open' question.
Type of question example
Open Tell me about the pain?
Closed What does the pain feel like?
Leading Does the pain feel like an electric shock?

6. Open question
Advantage
A. Allows patients to use their own words and summarise their view of the problem
B. Allows patients to partly direct the history-taking, gives them confidence and quickly
generates rapport
Disadvantage
A. clinicians must listen carefully and avoid interruptions to extract the relevant
information Patients
B. tend to decide what information is relevant

7. Closed question
Advantage
A. Elicits specific information quickly.
B. Useful to fill gaps in the information given in response to open questions
C. Prevents vague patients from rambling away from the complaint
Disadvantage
A. Patients may infer that the clinician is not really interested in their problem if only
closed questions are asked
B. Important information may be lost if not specifically requested
C. Restricts the patient's opportunities to talk

8. Summary of taking a history
A. Introduce yourself and greet the patient by name
B. Put patients at their ease
C. Start with an open question
D. Mix open and closed questions
E. Avoid leading questions
F. Avoid jargon
G. Explain the need for specific questions
H. Assess the patient's mental state
I. Assess the patient's expectations from treatment

9. Demographic details
The age, gender, ethnic group and occupation of the patient should
be noted.

10. History of the present complaint
A. Record the description of the complaint in the patient's own words
B. Elicit the exact meaning of those words
C. Record the duration and the time course of any changes in symptoms
or signs
D. Include any relevant facts in the patient's medical history
E. Note any temporal relationship between them and the present
complaint
F. Consider any previous treatments and their effectiveness

11. Taking a pain history
Characteristic Informative feature
Type Ache, tenderness, dull pain, throbbing, stabbing,
electric shock.
severity Mild — managed with mild analgesics Moderate
unresponsive to mild nalgesics Severe —disturbs sleep
Duration Time since onset. Duration of pain or attacks.
Nature Continuous, periodic or paroxysmal.
Initiating factors Any potential initiating factors. Association
with dental treatment

12. Exacerbating and relieving factors Record all and note especially
hot and cold sensitivity or pain
on eating which suggest a dental cause.
Localisation The patient should map out the
distribution of pain if possible.
Is it well or poorly defined?
Referral try to determine whether the pain
could be referred.

13. The medical history
A medical history is important as it aids the diagnosis of oral
manifestations of systemic disease.
It also ensures that medical conditions and medication which affect dental
or surgical treatment are identified.

14. example of a medical history questionnair
SURNAME………………………………………Address………………………….
Other name…………………………………………………………………………...
Date of birth……………………………………Telephone number……………….
The following questions are asked in the interests of your safety and any particular
precautions that may need to be taken as a result of present any previous illnesses or
medications.
1. Are you undergoing any medical treatment at present? Yes no
2. Do you have, or have you had any of the following:
a. Heart disease? Yes No
b. Rheumatic fever? Yes No
c. Hepatitis? Yes No
d. Jaundice? Yes No
e. Epilepsy Yes No
f. Diabetes? Yes No

15. g. Raised blood pressure? Yes No
h. Anaemia ? Yes No
I . Asthma, hay fever or other allergies? Yes No
j. Familial or acquired bleeding tendencies? Yes No
3. Have you suffered allergy or other reactions (rash, itchiness etc) to:
a. Penicillin? Yes No
b. Other medicines or tablets? Yes No
c. Substances or chemicals? Yes No
4. Have you ever had any adverse effects from local anaesthetics? Yes No
5. Have you ever experienced unusually prolonged bleeding after injury or tooth
extraction? Yes No
6. Have you ever been given penicillin? Yes No
7. Are you taking any medicines, tablets, injections (etc.) at present? Yes No
If YES can you please indicate the nature of this medication? …………………………..

16. 8. Have you been treated with any of the following in the past 5 years:
a. Cortisone (hydrocortisone, prednisone etc)? Yes No
b. Blood-thinning medication? Yes No
c. Antidepressants? Yes No
9. Have you ever received radiotherapy? Yes No
10. Do you smoke? Yes No
If YES how much on average per day?.....................................
11. For female patients — are you pregnant? Yes No
PLEASE ADD ANY OTHER INFORMATION OR COMMENTS ON YOUR MEDICAL
HISTORY, BELOW
.....................................................................................................
Signature ……………………………………date………………….
Address (if not the patient)…………………………………………

17. The dental history
A dental history and examination are obviously essential
for the diagnosis

18. The family and social history
Whenever a symptom or sign suggests an inherited
disorder, such as haemophilia, the family history should be
elicited.
social history which can be effect , for example,
psychosomatic factors

19. Consent
t is imperative to obtain patients' consent for any procedure. At the very
least, the procedure to be used should be explained to the patient and
verbal consent obtained.
A Consent Form should therefore be used and should state
1.The type of operation or investigation.
2. Possible risks and complications
3. A signed and dated statement by the clinician that he or she has
explained these matters and any options that may be available in terms
understandable to the patient, parent or guardian.

20. 4. A section for the patient, parent or guardian to confirm;
a. that the information was understandable.
b. that the person signing the form has a legal right to do so, i.e. is the
patient, parent or guardian
c. that the procedure has been explained and agreed
d. that there are certain additional procedures that would be completely
unacceptable and should not be carried out.

21. Extra-oral examination
Learning objectives
• know how to palpate lymph node
• be able to identify and assess swellings, sensory disturbance and motor
disturbances
• understand what to look for based on the history

22. Visual areas would cover
• general patient condition
• symmetry
• swellings
• lips/perioral tissues.
Palpation would cover:
• lymph nodes
• temporomandibular joint (TMJ)
• salivary glands
• problem-specific examination.

23. Lymph node examination
The major lymph nodes of the maxillofacial region and neck are submental ,
submandibular and the internal jugular nodes ( jugulo-digastric and jugulo-omohyoid
node being the largest) are of particular importance because these receive lymph
drainage from the oral cavity. Examination of the nodes should be systematic, although
the order of examination is not critically important.
To palpate the nodes, the examiner should stand
behind the patient while he/she is seated in an
upright position. Use both hands. A common sequence would
be to start in the submental region, working back to the
submandibular nodes then back to the jugulodigastric
node. Then continue by palpation of
the parotid region downwards to the retromandibular
area and down the cervical chain of nodes.

24. a. Submental
b. Submandibular
c. pre auricular
d. Post auricular
e. Occipital
f. juculo. digastric
g. Juculo omohyoid
h. Mid jucular
i. Mid posteriar cervical
j. Lower jucular
k. Lower posterior cervical

25. Temporomandibular joint

26. Temporomandibular joint
Joint examination
Movement.
Face the patient and ask him/her to open slowly to maximum. Normal range (inter-
incisal) is 35 to 40 mm. If opening is thought to be reduced, ask whether the limiting
factor is pain or an obstruction. Note the path of opening and any lateral deviation.
Pain on palpation.
Palpate in front of the ear and within the external auditory meatus.
Auscultation.
This needs a stethoscope to be done properly. However, clicks may well be audible
without a stethoscope.

27. Salivary glands

28. Salivary glands
As always, symptoms are often indicative of the abnormality present.
These can include:
• slowly developing swelling or mass, suggesting a tumour
• swelling (at the site of a major gland) associated with sight/taste/smell of food, slowly
subsiding subsequently, suggesting obstruction by calculus
• pain and swelling (of a major gland) perhaps with a bad taste, suggesting infection
• dry mouth, suggesting a wide range of causes, including Sjogren's syndrome.

29. Problem-specific examination
The examination will be made in the light of the symptoms
reported by the patient
But the examiner may detect swelling, sensory or motor
disturbance that the patient has not noticed.

30. Swelling/lump
.anatomical site
.shape and size
.colour
.single or multiple
.surface texture/warmth
. tenderness
. fluctuation
.sensation/pulsation
To assess fluctuation, place two fingers on the swelling and press down with one finger.
If fluid is present the other finger will record an upward pressure. Pulsation in a swelling
will indicate direct (i.e. it is a vascular lesion) or indirect involvement (i.e. in immediate
contact) of an artery.

31. Paraesthesia / anaesthesia
It is important to identify the extent of the affected area and the degree of alteration in
sensation It is best to use a fairly fine, but blunt-ended, instrument for this at first, for
example the handle of a dental mirror. First, run the instrument gently over what is
assumed to be a normal area of skin . Then repeat this over the symptomatic area,
asking the patient to say whether they can feel anything. Record the area of altered
sensation in the notes using a drawing.

32. Paralysis/motor disturbance
While paralysis or motor disturbance may be reported as a symptom by the patient, it
may initially be identified during an examination. In the maxillofacial region, the motor
nerves that are likely to be under consideration are the facial nerve, the hypoglossal
nerve and the nerves controlling the muscles that move the eyes.
The latter is seen in a large number of conditions but, for the dentist, important
causes include Bell's palsy , parotid tumours, a misplaced inferior dental local
anaesthetic and trauma.

33. Trigeminal nerve
V1 ophthalmic division
V2 maxillary division
V3 mandibular division
Cervial nerve
C2 _c4 branches

34. Sjogrens syndrome

35. Sjogren's syndrome
Sjogren's syndrome is an autoimmune chronic inflammatory disease involving the
salivary and lacrimal glands.
Diagnosis
/. Ocular symptoms
three selected questions
1. Have you had daily, persistent, trouble some dry eyes for more than 3 months?
2. Do you have a recurrent sensation of sand or gravel in the eyes?
3. Do you use tear substitutes more than three times a day?
//. Oral symptoms
three selected questions
1.Have you had a daily feeling of dry mouth for more than 3 months?
2. Have you had recurrently or persistently swollen salivary glands as an adult?
3. Do you frequently drink liquids to aid swallowing dry food?

36. ///. Ocular signs
two tests:
1.Schirmer's test
2. Rose Bengal score
IV. Histopathology
A focus score >1 in a minor salivary gland biopsy.
V. Salivary gland involvement
three diagnostic tests:
1.Salivary scintigraphy
2. Parotid sialography
3. Unstimulated salivary flow (<1.5 ml in 15 minutes)*
VI. Autoantibodies
Presence in the serum of the following antibodies:
1. Antibodies to Ro (SS-A) or La (SS-B) antigens, or both

37. Oral examination
Examination of the oral cavity can only be performed adequately with good
light, mirrors and compressed air or other means of drying the teeth.

38. Soft tissues
The soft tissues of the mouth should usually be inspected first.
Examination should be systematic to include all areas of the mouth.
ensure complete examination of the lateral tongue and posterior floor of mouth the
tongue must be held in gauze and gently extended from side to side.
After examination of the oral mucosa try to visualise the oropharynx and tonsils.

39. Teeth
As a minimum, the standing teeth with a summary of their periodontal health,
caries and restorative state, should be recorded.
When dental pain is a possibility, full charting, assessment of mobility and
percussion of teeth are necessary .

40. Some anatomical variants and normal structures often misdiagnosed as
lesions
Fordyce spots
Description
Sebaceous glands lying superficially in the mucosa are visible as white or
cream coloured spots up to 0.5 mm across. Usually labial mucosa and
buccal mucosa. Occasionally prominent and very numerous .

41. Lingual tonsils
Enlarge with viral infection and occasionally noted by patients. Sometimes
large or ectopic and then mistaken for disease.

42. Circumvallate papillae
Readily identifiable but sometimes prominent and misinterpreted by
patients or health care workers.

43. Retrocuspid papilla
Firm pink nodule 0.5-4 mm diameter on the attached gingiva lingual to the
lower canine and lateral incisor, usually bilaterally but sometimes unilateral.
Prominent in children but regress with age.

44. Dorsal tongue fur
Furring of the dorsal tongue mucosa is very variable and is heavier when the diet is
soft. Even light furring is regarded as pathological by many patients. When pigmented
black by bacteria the condition is called black hairy tongue.

45. Leukoedema
A milky white translucent whitening of the oral mucosa which disappears or
fades on stretching. Commoner in black races.

46. Exostoses in the midline of the palate or in the lingual alveolus in the
premolar region are termed tori.

47. Medical examination
The dentist should be capable of performing simple medical examinations of the head
and skin of the face, hair, scalp and neck may reveal unexpected foci of infection to
account for cervical lymphadenopathy or even malignant neoplasms.
The eye can readily be inspected for conjunctivitis or signs of mucous membrane
pemphigoid, anaemia or jaundice. Examination of the hands may also reveal relevant
information .

48. Useful diagnostic information from examination of the hands
Flexor surface of wrist
signs
Rash (or history of rash) consisting of purplish of papules suggests lichen planus,
especially if itchy.

49. Finger morphology
signs
Clubbing may be associated with some chronic respiratory and cardiac conditions
(including infective endocarditis) and sometimes remote malignancy.

50. Abnormal nails
signs
Koilonychia suggests long-standing anaemia Hypoplastic nails may be associated with
several inherited epithelial disorders of oral significance including ectodermal dysplasia
and dyskeratosis congenita

51. Skin of fingers
Signs
May be thin, shiny and white in Raynaud's phenomenon (periodic ischaemia resulting
from exposure to cold — often associated with autoimmune conditions particularly
systemic sclerosis or Sjogren's syndrome)

52. Palmar-plantar keratosis
signs
Associated with several syndromes including Papillon-Lefevre syndrome
(includes juvenile periodontitis).

53. Imaging
The most informative imaging techniques in the head and neck are radiography and
computerised tomography (CT), magnetic resonance imaging (MRI) and ultrasound.
Requirements for useful radiographic information
A. Always take bitewings when dental pain is suspected.
B. When imaging bony swellings always take two views at right angles
C. Panoramic tomograms cannot provide high definition of bony lesions. Only a cross-
section of the lesion is in the focal trough . For more information, oblique lateral views of
the mandible or oblique occlusal films should be taken
D. Radiography of soft tissues is occasionally useful, for instance to detect a foreign
body or calcification in lymph nodes.

54. Histopathology
Value and limitations
Removal of a biopsy specimen for histopathological examination is the mainstay of
diagnosis for diseases of the mucosa, soft tissues and bone.
Biopsy
Biopsy is the removal and examination of a part or the whole of a lesion
Types of biopsy
• Surgical biopsy (incisional or excisional)
Fixed specimen for paraffin blocks
Frozen sections
• Fine needle aspiration biopsy
• Thick needle/core biopsy

55. Essential biopsy principles
A. Choose most suspicious area
B. Avoid sloughs or necrotic areas
C. Give regional or local anaesthetic — not into the lesion
D. Include normal tissue margin
E. Specimen should preferably be at least 1 x 0.6 cm by 2 mm deep
F. Specimen edges should be vertical not beveled
G. Pass a suture through the specimen to control it and prevent it being swallowed or
aspirated by the suction
H. For large lesions, several areas may need to be sampled
I. Include every fragment for histological examination
J. Label specimen bottle with patient's name and clinical details
K. Suture and control any bleeding
I.

56. L. Warn patient of possible soreness afterwards. Give an analgesic
M. Check the findings are consistent with the clinical diagnosis and investigations
N. Discuss with pathologist or repeat biopsy if diagnosis is unclear or not understood

57. Surgical biopsy
Incisional biopsy (removal of part of a lesion) is used to determine the
diagnosis before treatment. Excisional biopsy (removal of the whole lesion
such as a mucocele) is used to confirm a clinical diagnosis.

58. Frozen sections
Frozen section technique allows a stained slide to be examined within 10 minutes of
taking the specimen. The tissue is sent fresh to the laboratory to be quickly frozen,
preferably to about -70°C .

59. Fine needle (FNA) aspiration biopsy
Even if not completely conclusive, the information from fine needle aspiration (FNA) is
often sufficient to distinguish benign from malignant neoplasms.

60. Exfoliative cytology
Exfoliative cytology is examination of cells scraped from the surface of a
lesion or occasionally of material in aspirates of a cyst

61. Brush biopsy
This technique uses a round stiff bristle brush to collect cells from the
surface and subsurface layers of a lesion by vigorous abrasion