Thyroid disorders
Introduction:
During his professional practice, the dentist will frequently be required to treat patients suffering from endocrine pathologies. Thyroid disorders are part of this and are relatively common (the second most widespread endocrine disease in the world after diabetes), their repercussions are at different levels (molecular, hormonal, cellular) and therefore on many anatomical sites, including the oral environment.
Through the history and clinical examination, the dentist will then be able to establish the link between a thyroid disorder and an oral pathology. This diagnosis will prove to be crucial when it comes to intercepting the disease and treating it to restore endocrine balance as quickly as possible, and the disappearance of oral manifestations.
Anatomical and physiological reminders:
Anatomical
The thyroid gland is a butterfly-shaped organ located just below the larynx.
It is composed of two lobes, joined by an isthmus resting in front of the anterior surface of the trachea.
Each lobe is about 4 cm long / 1 to 2 cm wide and lies on either side of the trachea.
Typically, the gland weighs about 30g. Richly vascularized, it receives between 80 and 120 ml of blood per minute.
Thyroid disorders
Thyroid hormones:
- triiodothyronine called T3 produced 10 to 25% by the thyroid.
- thyroxine called T4 produced by the thyroid.
- thyrocalcitonin which intervenes for the regulation of calcium, by helping its elimination through urine but also its fixation to the bones.
Average values of hormones:
Iodine intake is an important element for the proper functioning of the thyroid.
Too much iodine intake can lead to hyperthyroidism: the thyroid goes into overdrive and produces too many thyroid hormones, which causes the body to speed up.
A lack of iodine leads to hypothyroidism: the thyroid no longer produces enough hormones, which causes the body to slow down.
So:
hyperthyroidism = low TSH – high T3 and T4
hypothyroidism = high TSH – low T3 and T4.
3. Effects of thyroid hormones at the oral level
Thyroid hormones have multiple metabolic and tissue effects. All tissues respond in one way or another to their action. They stimulate or inhibit the activity of a large number of enzymes and this at several sites in the body but more particularly at the oral level.
3.1 Salivary impact
One of the major sites of action of thyroid hormones is saliva, they influence in particular its production and excretion.
The thyroid has a significant impact on the salivary glands and their secretions (T3 and T4 increase salivary secretion) and therefore acts on saliva but also on the roles of saliva and on salivary disorders. (dry mouth, carious lesions, etc.)
3.2 Bone impact
Thyroid hormones have an impact on bone growth and differentiation; Several studies have reported this phenomenon at the oral level. (Action on osteopontin which is a hormone inducing bone formation in fact thyroid hormones stimulate the expression of OPN therefore promote the formation of osteoblasts and the fixation of osteoclasts, which accelerates bone remodeling.
- Definition and etiologies of thyroid disorders
4.1 Hyperthyroidism:
thyrotoxicosis is the set of manifestations linked to excess circulating thyroid hormones which can come from:
An excess secretion of thyroid hormones (overall hypersecretion or by nodules), Graves’ disease (anti-TSH receptor antibodies)
2. An excess release of thyroid hormones by a cytolytic process destroying the thyroid (thyroiditis: autoimmune, induced by iodine, etc.)
3. An exogenous intake of thyroid hormones (factitious thyrotoxicosis)
4.2 Hypothyroidism:
Thyroid insufficiency: abnormal functioning of the thyroid
Thyrotropic insufficiency: due to a lack of stimulation of the thyroid by pituitary insufficiency
Familial or congenital character:
In association with other autoimmune diseases due to antibodies (Hashimoto’s thyroiditis):
ATPO: anti-thyroperoxidase antibodies
AntiTG: anti-thyroglobulin antibodies
Iodine deficiency (Nepal, Central Africa) responsible for severe thyroid insufficiency in utero with large goiter and irreversible neurological disorders
Infections: example: De Quervain’s thyroiditis
Inflammation of the thyroid gland of viral origin, painful, this disease is accompanied by fever and an increase in the size of the gland. Mild hypothyroidism may be found there.
Iodine: massive intake of iodine can block organification (this is the case with Amiodarone* and contrast agents)
Lithium*: Anti-thyroid action which can manifest itself after several years of treatment
Synthetic antithyroid drugs
Surgery
Other conditions:
Subacute thyroiditis
Painless thyroiditis:
Thyroid cancers
(causes, solitary nodule)
Thyroid nodules
20% cancerous can be adenomas cysts…
- Characteristic of hypo and hyperthyroidism:
hypothyroidism
hyperthyroidism
Chilliness
Intolerance to heat
Insufficient sweating
Excessive sweating
Dry and cold skin
Hot and humid
skin Hair loss
Loss of appetite
Increased appetite
Weight gain
Weight loss
Bradycardia
Tachycardia
Angina pectoris
Heart failure
Constipation
Diarrhea
Delayed thinking, memory impairment
Irritability
6- Treatment:
Hypothyroidism
Hyperthyroidism
Dietary modification
Antithyroid administrations (methimazole, propylthiouracil, etc.)
Administration of thyroxine (levothyrox)
B-blocker
Surgery (thyroidectomy..)
Oral manifestations of thyroid disorders:
7-Diagnostic approach:
Examination of the thyroid (palpation and inspection) should be included in the patient’s clinical examination at least during the first consultation.
A patient presents to the consultation with the following signs:
– nervous
– irritable
– heat intolerant
– tachycardic
– and having recently lost weight
– exophthalmos
– goiter or nodule on palpation
Intraorally:
– early eruption of temporary and permanent teeth
– a cyst of the thyroglossal tract
A hyperthyroid disorder should be suspected
A patient presents to the consultation with the following signs:
– apathetic
–
sluggish – intolerant to cold
– tachycardic
– having recently gained weight
Intraorally:
– large protruding tongue
– delayed dental eruption
– gingival hypertrophy –
ventilation through the oral cavity
Hypothyroidism should be suspected.
Thyroid disorders
- Action to be taken:
Refer the patient to a specialist doctor for a medical assessment and possible treatment
And if the diagnosis has already been established, the dental surgeon must know the precise diagnosis as well as previous and current treatments
Short-term care
Preferably carried out in the morning
Do not interrupt treatment
If the hyperthyroid patient is muscularly weakened, he must be placed in a semi-recumbent position
Antibiotic prophylaxis for hyperthyroid patients to combat the risk of infection
Sedative premedication is contraindicated in hypothyroid patients
Use of local anesthesia without vasoconstrictor in hyperthyroid patients
In case of emergency: provide care in a hospital setting
In case of a thyrotoxic crisis:
– injection of 100 to 200 mg of hydrocortisone
– hypertonic glucose infusion
– external cardiac massage
Will be undertaken while waiting for the SAMU
In case of concomitant pathology: need to take specific precautions
Conclusion
The management of a patient with a thyroid disorder in the dental office must always be done in collaboration with the treating physician.
Good training of practitioners is essential to ensure safety in the conduct of care.
Thyroid disorders
Deep cavities may require root canal treatment.
Interdental brushes effectively clean between teeth.
Misaligned teeth can cause chewing problems.
Untreated dental infections can spread to other parts of the body.
Whitening trays are used for gradual results.
Cracked teeth can be repaired with composite resins.
Proper hydration helps maintain a healthy mouth.