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RISK STARTIFICATION RISK STARTIFICATION AND DENTAL AND DENTAL

MANAGEMENT OF MANAGEMENT OF PATIENTS WITH THYROID PATIENTS WITH THYROID

DYSFUNCTIONDYSFUNCTION

Géza T. Terézhalmy, D.D.S., M.A. Géza T. Terézhalmy, D.D.S., M.A. Professor and Dean Emeritus Professor and Dean Emeritus

School of Dental Medicine School of Dental Medicine Cleveland, Ohio Cleveland, Ohio

[email protected]@uthscsa.edu

Terezhalmy 204/12/23

Thyroid DysfunctionThyroid Dysfunction

• Hypothalamic-pituitary-thyroid axis– Hypothalamus

• Thyrotropin-releasing hormone

– Anterior pituitary• Thyroid stimulating

hormone

– Thyroid gland• Tetraiodothyronine • Triiodothyronine



• T4 and T3– 70% bound to

thyroid binding globulin (TBG)

– 30% bound to transthyretin, albumin, and lipoproteins

– <2% circulate in an unbound free state• Act to maintain

physiological hormone levels



• T3– Accounts for most of the biological

activity of thyroid hormones• Stimulates RNA polymerase

– Transcription and translation» Growth and development» Thermoregulation» Calorigenesis» Carbohydrate, proteins, lipids metabolism» Oxygen utilization



• T3• Enhances tissue sensitivity to

catecholamines -adrenergic receptor activation

• Acts synergistically with epinephrine glycogenolysis



• Clinical manifestations– An estimated 5% of individuals in the

U.S. have palpable thyroid nodules• 95% are benign

– 85% hyperplastic nodules– 15% adenomas– <1% cysts

• 5% are malignant (30,180 cases in 2006)– 81% papillary carcinoma– 14% follicular carcinoma– 3% medullary carcinoma– 2% anaplastic forms



• Clinical manifestations– May be characterized as

• Euthyroid– Normal levels of thyroid hormones

• Hypothyroid– Inadequate levels of thyroid hormones

• Hyperthyroid– Excessive levels of thyroid hormones



• Clinical manifestations– Euthyroidism

• Euthyroid goiter (diffuse, nodular, multinodular)

• Benign tumors• Malignant tumors

– Differentiated (papillary, follicular)– Undifferentiated (small cell, giant cell)– Medullary



• Clinical manifestations– Euthyroidism

• Thyroiditis– Acute thyroiditis– Subacute (De Quevain’s) thyroiditis– Chronic autoimmune thyroiditis

» (Hashimoto’s disease)– Postpartum thyroiditis– Reidel’s thyroiditis



• Clinical manifestations– Hypothyroidism

• Congenital– 1:3,000-4,000 births

» Slightly incidence in the Hispanic population

» 85% is due to sporadic thyroid dysgenesis» 15% due to autosomal recessive mode of

inheritance– Recognized cause of mental retardation

» Symptoms begin to appear at about the 3rd month of life (cretinism)




• Congenital– Cretinism

» Puffy face» Large cranium» Flat and broad nose» Macroglossia» Thick elevated lips» Open mouth» Altered calcification of teeth» Delayed eruption of teeth




• Primary – Chronic

autoimmune thyroiditis

– Iatrogenic (surgery, 131I-therapy)

– Diffuse and nodular goiter

– Severe iodine deficiency




• Secondary– Pituitary




• Tertiary– Hypothalamic




• Clear female predominance (5-10:1)– 10 million in U.S. (8 million undiagnosed)

• Myxedema– Slow speech– Lethargy – Mental impairment– Depression– Increased sensitivity to cold– Pitting edema– Reduced rate of respiration




• Myxedema– Coarse facial

features» Thick lips» Puffy eyelids» Sad

expression– Dry hair– Dry and cold skin




• Myxedema– Muscle weakness– Cardiovascular abnormalities

» Slow pulse rate, coronary artery disease, hypotension, cardiomyopathy

– Laboratory abnormalities Aspartate transaminase Alanine transaminase LDH Creatinine Cholesterol






• Myxedema coma– Precipitating factors

» Infection» Exposure to cold» Sedative drug therapy» Pulmonary disease» Congestive heart failure» Gastrointestinal bleeding» Acute thyroid trauma» Noncompliance with thyroid supplementation




• Myxedema coma– Signs and symptoms

» Progressive alveolar hypoventilation» Hypothermia» Bradycardia» Decreased cardiac contractility» Hyponatremia» Decreased glomerular filtration» Coma




• Myxedema coma– Treatment

» Prompt administration of thyroid hormone» Ventilatory support» Fluid restoration» Glucose administration» Glucocorticoid administration

– Mortality rates» 20 to 60% have been reported



• Clinical manifestations– Hyperthyroidism

• Clear female predominance (5-10:1)– Hyperthyroidism

» 4.5 million in the U.S. (600,000 undiagnosed)• Glandular hyperfunction

– Diffuse hyperthyroid goiter (Grave’s disease)– Multinodular hyperthyroid goiter (Plummer’s

disease)– Autonomous nodule

• Thyrotoxicosis– Exogenous thyroid hormones


Thyroid Dysfunction




• Goiter• Exophthalmia

– Gritty sensation– Light sensitivity– Increased

tearing– Double vision– Felling of

retroocular pressure




• Facial flushing • Warm and moist skin• Enlarger lymph nodes• Tremor • Excitability • Emotional instability• Increased appetite with weight loss• Osteoporosis• Rapid rate of respiration




• Cardiovascular abnormalities– Tachycardia– Atrial fibrillation– Heart murmur– Hypertension

• Laboratory abnormalities Hypercalcemia Cholesterol Alkaline phosphatase (heat labile-bone)






• Thyroid storm– Precipitating factors

» Infection» Non-thyroid trauma» Psychosis» Parturition» Myocardial infarction» Intake or radioiodide and high doses of

iodine-containing compounds» Amiodarone therapy» Discontinuation of antithyroid therapy» Thyroid overdose




• Thyroid storm– Signs and symptoms

» Fever >101.30F» Tachycardia» CNS dysfunction (agitation, confusion,

delirium)» Gastrointestinal dysfunction (nausea,

vomiting, diarrhea)» Diaphoresis» Arial fibrillation» Congestive heart failure




• Thyroid storm– Treatment

» Intensive care» B-adrenergic blocking agents» Propylthiouracil» External cooling



• Diagnosis– Newborns

• Mandatory TSH testing– Adults, serum TSH concentrations

• Hypothyroidism TSH and free T4

• Hyperthyroidism TSH and free T4

– Specialized testing• Anti-thyroglobulin antibody (TgAb)• Anti-thyroid peroxidase antibody (TPOAb)• Anti-thyroid receptor antibody (TRAAb)



• Principles of medical management– Hypothyroidism

• Purified or synthetic thyroid preparations– Daily dosages, 0.05 to 0.15 mg, or its

equivalent» Inadequate replacement therapy is associated

with continued clinical features of hypothyroidism

» Substantial over-treatment results in clinical manifestations of hyperthyroidism



Drug Mechanisms of action Indication ADEs

Levothyroxin (Levoxyl®, Levothyroxin®, Synthroid®)

T4 and T3 replacement Drug of choice

Hyper-thyroidism

in overdose

Liothyronine (Cytomel®, Triostat®)

T3 replacement

When absorption of levothyroxin is inadequate

Liotrix (Thyrolar®)

T4 and T3 replacement

When conversion of levothyroxin, T4 to T3, is abnormal



• Principles of medical management– Hyperthyroidism

• Antithyroid drugs– Primary treatment, therapy is stopped or tapered

after 12 to 18 months of therapy» Lifelong follow-up is required as spontaneous

hypothyroidism may develop decades later OR Preparative therapy before surgery or radioiodine

therapy• Iodine or iodide preparations

– Short-term benefits » Decrease vascularity and size of the thyroid

gland in preparation to surgery




Methimazole (Tapazole®)

Inhibits the transformation of inorganic iodine to organic iodine

Long-term thyroxin suppressionORIn preparation for surgery or radioiodine therapy

AgranulocytosisHepatotoxicityUrticaria ArthralgiaSialadenitis (rarely)




Propyl- thiouracil

Inhibits the transformation of inorganic iodine to organic iodineANDBlocks the conversion of T4 to T3

Long-term thyroxin suppressionORIn preparation for surgery or radioiodine therapy

AgranulocytosisHepatotoxicityUrticariaArthralgia




IodineORIodide

Short-term inhibition of thyroxine release

Adjunctive therapy to antithyroid drugs OR In preparation for surgery

Allergic reactions



DENTAL MANAGEMENT

CONSIDERATIONS



• Goals– Develop and

implement timely preventive and therapeutic strategies compatible with the patients’ physical and emotional ability to undergo and respond to dental care

• Medical history– Review of organ

systems– Drug History



• Functional capacity– T3 exerts direct

inotropic and chronotropic effects on cardiac muscle

– T3 is synergistic with epinephrine

– Metabolic equivalents (METs)• Ability of the CV

system to meet metabolic demand for oxygen– Poor functional

capacity» < 4 METs



• Vital signs– Blood pressure

• < 180/110 mm Hg– Not an

independent risk factor for cardiovascular risk in association with non-cardiac procedures

• > 180/110 mm Hg constitutes a medical emergency

• < 90/50 mm Hg reliable sign of shock

– Pulse pressure, rate, and rhythm• Pulse pressure

correlates closely with systolic BP– Reliable

cofactor to either rule out or confirm significant CVD

• Pulse rate – <50 or >100

beats/min constitutes a medical emergency



• Treatment strategies– The physiological

events associated with the thyroid dysfunction and the “stress” of a procedure can affect cardiac function (myocardial ischemia)

• Procedure-specific variables– Fluid shifts or– Blood loss– Duration

of the procedure

– Physiological stress

• Dental procedures– Very low risk

* Oral Surg Oral Med Oral Pathol Oral Radiol Endod

1996;82:42-46*Arch Intern Med

2001;161:1509-1512*JADA

2001;132:1570-1579



– The hypothyroid patient• There is no

evidence to justify deferring needed surgery in patients with mild to moderate hypothyroidism

*Am J Med 1983;14:893-897

*Am J Med 1984:77:261-266

– The hyperthyroid patient• The effects of

undiagnosed or undertreated hyperthyroidism on the heart carries perioperative risks– Increased

cardiac output may limit cardiac reserve during surgery

*N Engl J Med 2001;344:501-509



– The use of local anesthetic agents with epinephrine• The hypothyroid

patient– No evidence of

adverse effects associated with epinephrine infusion in patients with hypothyroidism

*Clin Endocrinol 1995;43:747-751

• The hyperthyroid patient– Thyroid

hormones act synergistically with epinephrine» Use

epinephrine with caution



– The use of analgesics and anxiolytic agents• The hypothyroid

patient– Hyper-reactive

to CNS depressants» Use

judiciously

• The hyperthyroid patient– ASA displaces

thyroid hormones from their protein binding sites



Predictors of risk

Physical examination

Treatment options

Consultation or referral

EuthyroidORMild to

moderate thyroid dysfunction

AND/ORMinor or

intermediate predictors of CV risk

Blood pressure < 180/110 mm HgANDNormal pulse pressure, rate, and rhythmANDFunctional capacity > 4 METs

Comprehensive care

Routine referral for medical management and risk factor modification



Predictors of risk


Treatment options


EuthyroidORMild to


AND/ORNo major

predictors of CV risk

Blood pressure < 180/110 mm HgANDNormal pulse pressure, rate, and rhythmANDFunctional capacity < 4 METs

Limited careRoutine medical referral



Predictors of risk


Treatment options


EuthyroidORMild to


AND/ORNo major


BP > 180/110 mm Hg ORSystolic BP < 90 mm HgAND/ORAbnormal pulse pressure, rate, and rhythm

Emergencycare

If patient is asymptomatic

Routine medical referral

If patient is symptomatic

Immediate medical referral



Predictors of risk


Treatment options


Severe hypo-thyroidism

ORThyrotoxicosisAND/ORMajor


Establish baseline vital signs

Emergency care

Immediate medical referral



• Preventive strategies– Oral hygiene

• Conventional vs. electromechanical toothbrushes

– Antibacterial mouthwashes– Topical fluorides– Sialagogues

• Pilocarpine (Salagen)• Cevimeline (Evoxac)



• Potential medical emergencies– The likelihood of

myxedema coma or a thyroid crisis in the oral health care setting is extremely remote• Other medical

emergencies may be anticipated based on the patient’s medical history and vital signs


Risk stratification of patients with TDRisk stratification of patients with TD

• Huber MA, Terezhalmy GT. Risk stratification and dental management of the patient with thyroid dysfunction. Quintessence Int 2008;39:139-150.

• Pickett FA, Terezhalmy GT. LWW’s Dental Drug Reference with Clinical Implications. 2nd ed. Baltimore: Wolters Kluwer Health / Lippincott Williams & Wilkins, 2009.

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