Dr. Reham Lotfy AggourLecturer of oral Medicine,

Periodontology, Oral diagnosis and Radiology

Significant lab tests in dentistry

HEMATOLOGIC TESTS

Includes:CBC: Complete Blood Count with

Platelet and WBC differential.ESR: Erythrocyte Sedimentation

Rate.Laboratory tests assessing

haemostasis.

Complete Blood Count• RBCs: 4.2-5.9 million/mm3 • Hemoglobin: males: 14-18 g/dl female: 12-16 g/dl• Haematocrit: males: 40--54 % female: 37-47 %• MCV (mean corpuscular volume): 86-98 fl /cell• MCH (mean corpuscular hemoglobin): 27-32 pg/RBC• MCHC : 30-33%• Platelet: 150.000- 400.000 /mm3

Complete Blood Count• WBCs: 4.000-10.000 /mm3 • WBCs differential: Neutrophils: 60-70% Lymphocytes: 20-35% Monocytes: 1-10% Eosinophils: 1-6% Basophils: 0-2%

Increased RBCsPolycthemia

• erythrocyte count of 6 to 12 million/mm3 with a hemoglobin concentration of 18 to 24 g/dL. Hct also increase.

Causes: • Hypoxia (high altitude or

vigorous physical activity) → ↑ erythropoietin production by the kidney → ↑ RBCs

• Polycythemia vera (primary proliferative polycythemia)

• Secondary polycythemia (chronic pulmonary disease, congenital heart disease).

Anemias by RBC Patterns• ↓Hb; ↓Hct; ↓MCV; ↓MCH: microcytic hypochromic

anemia:1. Iron deficency anemia2. Thalathemia• ↓Hb (hemoglobin); ↓ Hct; ↑ MCV; ↑ MCH: : Macrocytic

megaloblastic pattern.1. Vitamin B12 deficiency2. Folic acid deficiency• ↓Hb; “N” MCV & “N” MCH: normocytic

normochromic pattern:1. Aplastic anemia2. Acute hemolysis3. Chronic disease

Oral Manifestations of anemia

Leukocytosis= increased WBC

Physiologic• exercise .• Stress.Pathologic• Infection.• Allergies. • Necrosis.• drugs. • LEUKEMIA

Gingival leukemic infiltrate in a patient newly diagnosed with acute myelogenous leukemia.

Bleeding tendency may occur in leukemic pts due to bone marrow infiltration leading to thrombocytopenia

Increased incidense of infection is a sign of any immunocompromised patient including leukemic pts

Leukocytosis: Diff. Analysis• Diff. is used to follow the course of diseases,

infections, and neoplastic conditions.1. ↑ WBC count &neutrophils → Acute bacterial

infection, sterile inf., mylogenous leukemia2. ↓ Neutrophils, ↑ lymphocytes → Viral

infections, ch. Infection, lymphoblastic leukemia

3. ↑ Monocytes → Chronic bacterial infections, infectious mononucleosis, monocytic leukemia

4. ↑ Eosinophils → Allergies, parasites, Hodgkinʼs lymphoma.

5. ↑ Basophils → CMV, polycythemia

-Lymphadenopathy may be due lymphoma or lymphoblastic leukemia

1. ↓ Neutrophils, ↑ lymphocytes → Viral infections, ch. Infection, lymphoblastic leukemia, lymphoma

-Lymphadenopathy may be due mylogenous leukemia

1. ↑ WBC count &neutrophils → Acute bacterial infection, sterile inf., mylogenous leukemia

Leucopenia: ANC• ANC: Absolute Neutrophil Count• ANC: 1.500: 7.200 cells/mm3 • ANC calculation: WBC× (%neutrophils+%Bands)• Leucopnia is caused by: 1. Drugs2. Bone Marrow suppression3. Some viral and bacterial infections4. Radiation• The most common cause is chemotherapy

Leucopenia: Dental precautions• ANC below 1.500 cells/mm3 predicts the risk of

infection (mild, moderate, or severe).1. 1.000-1.500 cells/mm3 → mild risk of infection

2. 500-1000 cells/mm3 → moderate risk of infection

3. Less than 500 cells/mm3 → life threatening sepsis risk.

Neutropenia: Infection S/S

• oral ulcerations in Neutropenic patient(necrosis, severe pain , prolonged duration, no pus)

Platelets

• Normal platelet count: 150.000: 400.000 cells/mm3

• Primary hemostasis needs adequate platelet count &function

Thrombocytopenia

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

Case 1• A 27 year old male complains about

bleeding gums and several recent onset of epistaxis. Examination revealed a pale appearance.

• Investigations shows:Haemoglobin: 8.0g/dlHaematocrit: 24%MCV: 88 fl (NR:86-98 fl /cell)White cell count: 2000 /mm3

Neutrophils: 20%Lymphocytes: 77%Platelets: 40.000/mm3

Blood film showed normocytic erythrocytes

The most likely diagnosis is:

1. Iron deficiency anemia

2. Thalasemia3. Pernicious anemia4. Aplastic anemia

CASE 2

• A 18 year old man presented with a 3 week history of generalized gingival enlargement and painless cervical lymphadenopathy.

• Which of the following investigations should be performed?

1) Blood glucose level2) Panoramic x-ray3) Complete blood count4) Prothrombin time

Case 3• A 19 years old man presents

immediate profuse bleeding after extraction of one of his lower teeth. No local cause has been identified. On further questioning, he gives a history of chronic gastric ulcer.

• Investigation shows:Hb: 6.7MCV : 58.0 fl (NR:86-98 fl /cell)WBC: 13.000 /mm3

Neutrophils : 10.000 /mm3

Platelet: 503.000 /mm3

• The most likely cause of bleeding is:

1. Thrombocytopenia2. Iron deficiency anemia3. Aplastic anemia4. Haemophilia

Case 4• A 65-year old lady treated

by antifungal for oral candidiasis. She reported being free for 2 weeks but the lesion recurs . Investigation shows:

Hb 13.5 g/dlPlatelets 170.000 /mm3

White blood cells 30.000/mm3

Lymphocytes 26.000/mm

Neutrophils 3.200/mm

• What is the possible cause of recurrence? Explain.

CASE 5• A 55-year old lady presented to

his dentist with a complain of burning sensation in her mouth especially her tongue. She also reported having tingling in her feet and hands and being fatigued. Investigation shows:

Hb 4.5 g/dl ( no. 11.5-15.5)Haematocrit 19 (no. 0.38-0.47)MCV 118 FL (no. 80-96)MCH 33.0 PG (no. 28-32)Platelets 95.000 /mm3

White blood cells 8.000/mm3

• What is the cause of burning? Explain.

• A 26-year old man presented to his dentist with spontaneous gingival bleeding. History revealed six month history of fatigue and dyspnea:

Hb 7.5 g/dlPlatelets 12.000White blood cells 300.000/mm3

Neutrophils 34% (normal 60-70%)Blast 1%

• What is the cause of bleeding? Explain.

• A 15-year old girl presented to his dentist with a complain of spontaneous bleeding and palatal bruising. She denied having any trauma but reported having a mild viral infection a week ago. Investigation shows:

Hb 14.5 g/dlPlatelets 15.000 /mm3

White blood cells 7.000/mm3

• What is the cause of bleeding? Explain.

Other hematological testsReticulocyte count

• Assess bone marrow activity• Raised in: Hemolytic anemiaAcute blood lossAfter iron therapy

• A 25-year old man presented to his dentist complaining of parathesia of his tongue. During examination, the dentist observed yellowish discoloration of his sclera, skin and oral mucosa. He asked for investigation which shows:

Hb 7.5 g/dlReticulocyte 6.28% (NR 0.5-2.4%)Platelets 266.000Bilirubin 45 mg/dl (NR0.3-1.0 mg/dl)AST 36 IU/L (NR 10-40 U/L) APT 40 IU/L (NR 9-60U/L)

• What is the cause of his complain? Explain.

• 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/dlReticulocyte 6.2% (NR 0.5-2.4%)Platelets 166.000Bilirubin 4 mg/dlAST 20 IU/L (NR 10-40 U/L) APT 30 IU/L (NR 9-60U/L)

• What is the cause of yellowish discoloration? Explain.

• A 32-year old man presented to his dentist with massive submandibular space infection. History revealed that the patent is on chemotherapy for lymphoma.

• On examination , he appeared unwell. He was febrile 39.5 and he was unable to open his mouth. Investigation revealed:

Hb 11.5 g/dlPlatelets 152.000White blood cells 2.000/mm3

Neutrophils 10 % (normal 60-70%)Lymphocytes 80%

• What is the best action? Why?