lab investigation for dental student (oral medicine and diagnosis II)

1. Dr. Reham Lotfy Aggour
Lecturer of oral Medicine,
Periodontology, Oral diagnosis
and Radiology
Significant lab tests in
dentistry

2. HEMATOLOGIC TESTS

3. Includes:
CBC: Complete Blood Count with
Platelet and WBC differential.
ESR: Erythrocyte Sedimentation
Rate.
Laboratory tests assessing
haemostasis.

4. Platelets
• Normal platelet count: 150.000:
400.000 cells/mm3
• Primary hemostasis needs adequate
platelet count &function

5. Thrombocytopenia

6. For periodontal or
maxillofacial surgery
platelet count should be
above 75.000/mm3
For major surgeries with
general anesthesia
platelet count should be
above 100.000/mm3
Spontaneous bleeding
occurs when the platelet
count is below
20.000/mm3

7. Elements of Hemostasis
1. Adequate blood vessel response.
2. Adequate platelet count.
3. Adequate platelet function: Bleeding time.
4. Adequate level of Von Willebrandʼs factor.
5. Adequate levels of clotting factors : PT/INR, PTT.

8. Clotting Factor Tests
PT (Prothrombin Time)
• Tests extrinsic and common
pathways.
• Normal (11-15 sec)
• Coumarin therapy PT at 1.5
to 2.5 time
• International normalized
ratio INR=1
• Surgery can be done if INR <
3
Partial thromboplastin
time (PTT)
• Tests intrinsic pathway.
• Normal (25-35sec).
• Affected by heparin
anticoagulant

9. Case 1
A 59 years old man
presents to the dental
office for extraction of
one of his lower teeth.
History reveals that he
had 2 venous
thromebolic events and
is on warfarin therapy
(oral anticoagulant):
• Which of the following
investigations should
be performed to
evaluate the risk of
bleeding?
1) Blood glucose level
2) ESR
3) Complete blood count
4) Prothrombin time

10. Case
2
A 18-year old female complains about gingival
bleeding and epistaxis in addition to the above
lesions.
1) What are the lab investigations that should be
performed?

11. • A 26-year old man attend the
dental office for extraction of one
of his teeth. History revealed
spontaneous gingival bleeding .
Investigation shows:
Hb 13.5 g/dl
Platelets 12.000
White blood cells 6.000/mm3
PT (13 sec)
PTT (26 sec)
• What is the cause
of bleeding?
Explain.

12. • A 28 year old lady was
diagnosed with acute
leukemia. She required
extraction of her lower
third molar. Her platelet
count was found to be
11.000/mm₃
• What is the best
action? Why?

13. • A 15-year old girl presented
to her dentist with a
complain of spontaneous
bleeding and palatal
bruising. Investigation
shows:
Hb 14.5 g/dl
Platelets 17.000 /mm3
White blood cells 7.000/mm3
PT (11 sec)
PTT (23 sec)
• What is the cause of
bleeding? Explain.

14. • A 37-years old female who
has a prosthetic valve came to
the dental office complaining
of left submandibular
swelling. A history of dental
pain in the lower left
quadrant was reported. On
examination a tender left
unilateral swelling, limited
mouth opening and partially
impacted lower left wisdom
were observed. The dentist
decided that this wisdom is
indicated for surgical
extraction.
• Mention the needed
laboratory tests and its
normal values?
• What is the best treatment
approach based on the
result of the laboratory
tests?

15. Laboratory Diagnostic Criteria for
Diabetes
Diagnosis is by any of the following three methods and must be
confirmed on a subsequent day by any one of the same three
methods.
• 1. Presence of diabetes symptoms plus casual (nonfasting) plasma
glucose ≥ 200 mg/dL (casual glucose may be drawn at any time of day
without regard to time since last meal)
• 2. Fasting plasma glucose ≥ 126 mg/dL (fasting is defined as no caloric
intake for at least 8 hours)
• 3. Two-hour postprandial glucose† ≥ 200 mg/dL during an oral glucose
tolerance test using a glucose load containing the equivalent of 75 g
of anhydrous glucose dissolved in water

16. Uncontrolled DM : Management

17. Case 2
A 55-diabetic male
complaining of
burning sensation in his
tongue. On
examination a
diagnosis of
pseudomembranous
candidiasis was
confirmed . His last
random blood glucose
level was 350mg/dl .
1) What is the normal value
of random blood glucose
level?
2) What is the appropriate
treatment?

18. AIDS Definition
• An individual is diagnosed with AIDS if
signs or symptoms from CDC defined
Clinical Category C are present.
• CD4 cells count is bellow 200 cells.

19. Centers for Disease Control and Prevention
classification .
CD4+ T Cells/mm3
or
CD4+ Percentage
Clinical Categories
≥ 500 or ≥ 29% A1 B1 C1*
200–499 or 14–
28%
A2 B2 C2*
< 200 or < 14% A3* B3* C3*
A: Asymptomatic Acute HIV or PGL
B: Symptomatic, no A or C Conditions
C: AIDS-Indicator Conditions
* Expanded acquired immunodeficiency
syndrome (AIDS) surveillance case definition.

20. Case 3
32 parentral drug user male came to
the dental office with a complain of
mild roughness and irritation related
to both lateral surfaces of the
tongue. He also reported a history
of frequent attacks of respiratory
tract and skin infections during the
last 3 months. The dentist diagnosed
the lesion as hairy leukoplakia
1. What condition is important to
exclude?
2. What lab. Investigation that
should be done?

21. Liver function tests
• Tests for hepatic function
• Tests for hepatobillary disease
• Tests of hepatocellular damage

22. Tests for hepatic function
• Serum albumin (3.5-5.5 mg/dl)
Serum half life of albumin is 14-20 days, and serum levels fall
with prolonged liver dysfunction or acute hepatic failure.
Malnutrition and renal or gastrointestinal losses needs
consideration in cases of hypoalbuminemia, especially if
prothrombin time is normal.
• Prothrompin time (10.5-13 sec)
The prothrompin time responds rapidly to altered hepatic
function so it is useful as a daily marker of hepatic
function. However, coexistent vit K def. Must be excluded.

23. Tests for hepatobillary disease
• Serum alkaline phosphatase (30-120U/L)
Increrased also in
 bone destruction/remodeling
 bile duct obstruction
 infiltrative liver disease (neoplasms, granulomas)
• Serum bilirubin (0.3-1.0 mg/dl)
Increrased also in
haemolysis in addition to billary obstruction
liver disease.

24. Tests of hepatocellular damage
• Aspartate aminotransferase (AST)(10-40 U/L): ↑ in
• hepatocellular necrosis
• cardiac or skeletal muscle necrosis.
• Alanine aminotransferase (9-60 U/L): ALT is more
specific for liver cell damage

25. Hepatitis B virus (HBV)
• HBV surface antigen (HBsAg) +ve in most cases of acute or chronic
infection.
• HBV e antigen (HBeAg) Indicates presence of viral replication and
high infectivity.
• HBV-DNA Its levels reflect degree of viral replication and predict response to
therapy.
• Anti-HBe Reflection of low infectivity
• Anti HBc (IgM or IgG) +ve in all cases of acute or chronic
infection.. IgM anti HBc reflects acute infection. Not protective.
• Anti-HBs+ve in late convalescence in most acute cases. Confers
immunity.

26. Hepatitis C virus (HCV)
• Anti-HCV +ve 6-8 wk after exposure, not
protective. Persistent in acute, chronic or
post infection.
• HCV-RNA Reflects ongoing infection. Levels
inversely linked to ttt response.

27. • A 25-year old man presented to his
dentist for oral hygiene prophylaxis.
During examination, the dentist
observed yellowish discoloration of
his sclera, skin and oral mucosa. He
asked for investigation which shows:
Hb 14.5 g/dl
Reticulocyte 0.68% (NR 0.5-2.4%)
Platelets 266.000
Bilirubin 45 mg/dl (NR 0.3-1.0 mg/dl)
AST 1 36 IU/L (NR 10-40 U/L)
ALT 240 IU/L (NR 9-60U/L)
• What is the
possible cause of
the yellow
discoloration?
Explain.

28. • A 56-year old man presented to
his dentist. During examination,
he observed yellowish
discoloration of his sclera, skin
and oral mucosa. He asked for
investigation which shows:
Hb 6.5 g/dl
Reticulocyte 6.2% (NR 0.5-2.4%)
Platelets 166.000
Bilirubin 4 mg/dl
AST 20 IU/L (NR 10-40 U/L)
ALT 30 IU/L (NR 9-60U/L)
• What is the cause of
yellowish
discoloration? Explain.

29. • A 66-year old lady presented to his dentist for
extraction of one of her upper molars. After
extraction, perfuse immediate bleeding
occurred. History revealed chronic fatigue
and nasal bleeding.
• Investigation shows:
Hb 8.5 g/dl
MCV 68 fl (No. 80-69)
Platelets 12.000 /mm3
White blood cells 6.000/mm3
PT (11 sec)
PTT (23 sec)
• What is the cause
of bleeding?
Explain.

30. A 55 years old man
attended dental clinic
complaining of several
bruises related to his
tongue and palate over
the past week without
any precipitating
trauma . history
revealed deep venous
thrombosis 2 months
ago.
1. What laboratory tests
that should be done ?

31. BONE METABOLISM
• Calcium (9.0-10.5 mg%).
• Phosphorous( 3.0- 4.5 mg%)..
• Alkaline phosphatase (25 - 115 Units/L).

32. Hypercalccemia:
• Hyperparathyroidism.
• Multiple myeloma.
• Paget’s disease.
• Osteoporosis .
• Cancer
Hypocalcemia:
• Hypoparathyroidism,
• Vit. D deficicency,
• Preganancy,
• Diuretics

33. A 65 years old woman
admitted to the hospital
following a mandibular
fracture that resulted
from a sudden fall from
her bed. history revealed
difficulty in climbing up
stairs in addition to
chronic fatigue. The
patient reported living in
a residential house. A
slight lordosis have been
detected
• Serum calcium: 7.5 mg/dl
• Serum phosphate:
2mg/dl
• Alkaline phosphatase
enzyme: 233 IU/L
1. What is your D.D?