Oral Pigmentation Overview

Oral Pigmentation

• Four pigments contribute to oral and skin color: melanin, carotenoids, reduced hemoglobin, and oxygenated hemoglobin.
• Melanin is the most significant pigment.
• Melanin is an endogenous, non-hematogenous pigment.
• Melanocytes produce melanin in the basal layer of the epithelium.
• Melanin is transferred to adjacent keratinocytes via melanosomes.
• Nevus cells also synthesize melanin; pigmentation varies by location (black, gray, blue, or brown).
• Pigmentation is the process of depositing pigments in tissues.
• Various diseases can lead to diverse oral mucosal colorations.
• Pigmented oral lesions arise from increased melanin production, increased melanocyte numbers (melanocytosis), or exogenous material deposition.
• Physiological oral pigmentation results from melanocyte activity variations, common in darker-skinned individuals.
• Pathological pigmentation is categorized as exogenous or endogenous, based on the cause.
• Exogenous pigmentation: induced by drugs, tobacco/smoking, amalgam tattoos, or heavy metals.
• Endogenous pigmentation: associated with endocrine disorders, syndromes, infections, chronic irritation, or neoplastic processes.

Exogenous Pigmentation of the Oral Mucosa

• Source | Color | Disease Process
• --|---|---
• Silver amalgam | Gray, black | Tattoo, iatrogenic trauma
• Graphite | Gray, black | Tattoo, trauma
• Lead, mercury, bismuth | Gray | Ingestion of paint or medicinals
• Chromogenic bacteria | Brown, green, black | Superficial colonization

Endogenous Pigmentation of the Oral Mucosa

• Pigment | Color | Disease Process
• --|---|---
• Hemoglobin | Blue, red, purple | Varix, hemangioma, kaposi's sarcoma, angiosarcoma, hereditary hemorrhagic telangiectasia
• Hemosiderin | Brown | Ecchymosis, petechia, thrombosed varix, hemorrhagic mucocele, hemochromatosis
• Melanin | Brown, black or gray | Melanotic macule, nevus, melanoma, basilar melanosis with incontinence

Drug-Induced Pigmentation

• Pigmentation can result from various drugs, including hormones, oral contraceptives, chemotherapeutic agents, tranquilizers, antimalarials, antimicrobials, anti-retrovirals, and antifungals.
• Common affected sites are the palate and gingiva.
• Teeth may appear bluish-gray due to minocycline/tetracycline use.

Tobacco-Induced Pigmentation

• Heavy tobacco use stimulates melanin production in areas of mucosal contact.
• This is a protective mechanism against tobacco elements like nicotine.
• Similar protection occurs in response to sun exposure.

Smoking-Related Pigmentation

• Smoking results in flat, light brown pigmentation, often diffuse, on the facial anterior gingiva, mandible, commissure, buccal mucosa, and hard palate.
• Excessive melanin production is the underlying cause.

Heavy Metals

• Elevated levels of metals (lead, bismuth, mercury, silver, arsenic, gold) cause oral mucosal discoloration.
• Plumbism (lead poisoning) shows a blue-black line along the marginal gingiva (Burtonian line).

Amalgam Tattoo

• One of the most common causes of oral pigmentation.
• Twice as common as melanotic macules and 10 times as common as oral nevi.
• Most commonly involves the gingiva and alveolar mucosa.
• Presents clinically as a localized, blue-gray lesion.
• Amalgamic particles in the connective tissue confirmed through biopsy.

Graphite

• Accidental incorporation during injury, commonly seen in children.
• Appears as an irregular gray to black macule on the anterior palate.

Primary Hypoadrenalism (Addison's Disease)

• Chronic adrenal cortical insufficiency leading to cell destruction (at least 90%).
• Causes may be tuberculosis, autoimmune disorders, massive hemorrhage, or metastasis.
• Characterized by hyperpigmentation, initially skin, then oral cavity, (increased ACTH and MSH levels).

Treatment for Addison's Disease

• Corticosteroid replacement therapy.
• Increased dosages during stressful events, including dental procedures that use local anesthesia usually do not warrant an increased dosage.
• Dental procedures needing higher dosages are usually performed with general anesthesia (GA).

Polyostotic Fibrous Dysplasia

• Developmental lesion replacing bone with dysplastic fibrous tissue.
• Caused by a genetic mutation.
• Polyostotic or monostotic, the latter being less serious.
• Feature of McCune-Albright syndrome (Café-au-lait pigmentation, fibrous dysplasia, endocrine dysfunction).

Neurofibromatosis

• Autosomal dominant disorder (NF1 and NF2).
• Characterized by café-au-lait pigmentation on the skin (patches of irregular brown/light brown).
• Patches generally greater than 5 cm in diameter.

Café-au-lait pigmentation

• Light brown, oval patches (greater than 5cm).
• Smooth borders.
• Often associated with other conditions.

Hemochromatosis

• Homozygous-recessive inherited disorder causing excessive iron absorption.
• Iron accumulates in various organs (e.g. liver, pancreas).
• Secondary hemochromatosis: a complication of parenteral iron administration.

Peutz-Jeghers Syndrome

• Autosomal dominant disorder with mucocutaneous macules.
• Increased risk of cancers (e.g., pancreas, gastrointestinal tract, thyroid, breast).
• Oral manifestations often involve the lips, buccal mucosa, gingiva, palate, and tongue.
• Shows increased melanin in the basal layer.

Posttraumatic Pigmentation

• Characterized by discoloration from hematoma, leading to secondary hemosiderin deposition.
• The discoloration varies from red to blue-black, depending on lesion age.
• Clinically, may be confused with pigment from other sources.
• Often occurs in trauma susceptible tissues (buccal mucosa, tongue, lips, junction of hard and soft palate).

Postinflammatory Pigmentation

• Characterized by mucosal pigmentation occurring in inflammatory diseases, particularly lichen planus (multiple brown/black pigmented areas adjacent to inflammation/erosive lichen planus).
• Microscopically shows melanin production from melanocytes with accumulation in the connective tissues.

Melanocytic Nevus/Melanocytic Macule

• Benign proliferation of melanocytes.
• May appear clinically similar to melanotic macules (increased melanocytes within basal epithelium or underlying connective tissues).
• Generally rare in the oral cavity, but are common skin lesions.

Bluish-gray Nevus of the Hard Palate

• Commonly seen on the hard palate; most often, presenting as slightly raised or flattened.
  • The color varies from colorless to dark blue. brown, or black
  • May be misdiagnosed for other lesions.

Oral Melanocytic Macule

• Multiple pigmened areas clinically, but microscopic examination reveals increased melanin in the basal layer (not just hyperplasia).
• Important to rule out other conditions like Addison's disease (which has increased melanin due to hormonal issues).
  • May be found on gingiva, lips, buccal mucosa.

Pigmented Malignant Lesion

• Melanoma is a malignant neoplasm of melanocytes, and oral melanomas commonly present on the hard palate as a brown/black macule with irregular margins.
• Note: Melanoma is a serious condition, and referral to a doctor is essential.

Oral Melanoma

• Diagnostic criteria use the ABCDE rule: Asymmetry, Border irregularity, Color variation, Diameter, and Elevation.

• Note: Consistent, accurate oral examination is needed to assess possible melanomas.

• Questions? (This was the final slide).

This quiz covers the significant aspects related to oral pigmentation, including the role of melanin and other pigments in oral and skin color. It discusses the physiological and pathological factors affecting pigmentation and is essential for understanding oral health implications. Test your knowledge on how various diseases influence oral mucosal coloration and the biology behind melanocyte activity.