Extensive Amalgam Tattoo and Oral Melanosis: A Clear Distinction

Why Is Extensive Amalgam Tattoo Commonly Misdiagnosed or Confused With Melanosis?

Oral pigmentation refers to the relative spectrum of disorders that comprises a broad range of factors, most of them diagnostic of an underlying local or systemic condition. One of the most common causes of black pigmentation in the oral cavity is exogenous pigmented oral mucosal lesions. There are varying oral mucosal black-pigmented lesions that resemble the amalgam tattoo. The amalgam tattoo is the most common iatrogenic (operator-induced) exogenous lesion (caused by materials or foreign bodies introduced from outside), that is often confused with the other common exogenous lesions of melanosis (abnormal deposition of melanin pigment). Now let us also look at the differences between amalgam tattoos and extensive amalgam tattoos. While the normal amalgam tattoo diagnosis can be simple as the lesions are usually slate grayish, blue, or black macular lesions (a flat discolored area of skin) - extensive amalgam tattoos are more unusual and rarely reported in the dental literature.

In extensive amalgam tattoos, there would be traumatic dental implantation of amalgam (dental alloy-based filling of mercury) into the soft tissues or the oral mucosal membranes. Be it the amalgam tattoo or extensive amalgam tattoo, the lesions always manifest as bluish-gray or grayish macules that may eventually even resemble black melanotic spots over some time, always closer to the amalgam-restored or filled tooth. Because there can be the potential for misdiagnosis with melanotic lesions, oral surgeons need to differentiate extensive amalgam tattoo lesions by performing a biopsy. Large-sized lesions can be biopsied, and microscopic examination will help in the differential diagnosis.

What Are the Causes of Melanosis?

It is to be noted that melanosis can be caused even by local factors such as smoking, which is one of the major irritants in the form of nicotine that can disrupt oral cell-mediated immunity and result in pigmentation. Further, other systemic diseases that can cause exogenous pigmentations that cause excess melanin deposition in the body are from complex diseases like Peutz-Jeghers syndrome (PJS) (a noncancerous genetic condition that causes the development of polyps in the gastrointestinal tract) and Addison disease (a condition in which body does not make certain hormones). Most often, when dental or maxillofacial surgeons are confronted with a differential diagnosis, then several considerations, including a biopsy, would be done to differentiate the melanin deposition or melanosis lesions or macules from amalgam tattoos. A simple dental or medical history elicited by the maxillofacial or oral surgeon first establishes whether the patient has had a recent or past history of amalgam fillings. Further, local and systemic factors of the patients need to be noted by the dentist to consider the differential diagnosis. This can help the dentist or dental operator differentiate the melanotic lesions or excess melanin deposition from amalgam tattoos.

How Can Microscopic Examination Reveal Extensive Amalgam Tattoos?

Microscopic examination of the amalgam tattoo reveals that the affected oral tissues consist of several discrete brownish or black granules that are dispersed around the collagen bundles as well as the smaller blood vessels and nerves. Based on the iatrogenic error and the extent of biological response, amalgam tattoos can often become extensive tattoos, where microscopic examination can reveal that large fragments are surrounded by dense connective tissue.

Further, in extensive amalgam tattoos, microscopic characteristics of macrophages that surround and engulf the smaller amalgam particles would be diagnostic of this condition. In very severe iatrogenic-induced extensive amalgam tattoos, multinucleated giant cells containing amalgam particles further prove the diagnosis.

In this condition, because the metallic amalgam particles are very finely dispersed, they cannot be as such very clearly differentiated on the dental radiographs or even through the modern CBCT (cone beam computed tomography) or CT (computed tomography) scan. Biopsy and microscopic examination hence remain the gold standard diagnostic criterion for differentiating oral pigmentations associated with melanin excess or melanosis from extensive amalgam tattoos.

If the dentist or maxillofacial surgeon detects the presence of extensive amalgam tattoos after biopsy and microscopic examination, no additional management or treatment modality is usually needed.

How Is Amalgam Substituted for Modern-Day Dental Restoratives?

With the advent of restorative dentistry over the last three decades, the conservative treatment of dental decay or cavitation holds importance in managing dental cases effectively, while also aiding in patients' esthetic and functional expectations of tooth rehabilitation.

Dentists and maxillofacial surgeons should therefore be careful during restorative procedures while handling dental amalgam, which is a primarily mercury-based dental filling material. Further, because of the introduction of several modern-day materials for dental fillings like composites, hybrid resins, ceramic fillers, and GIC (glass ionomer cement)-based fillings, restorative dentistry has seen a tremendous advance in the properties of dental materials and can substitute the traditional amalgam fillings that can be a possible hazard in sensitive patients. Further, there can be scope for iatrogenic errors such as the amalgam tattoo.

What Is the Management for Esthetic Versus Non-esthetic Oral Zones?

As extensive amalgam tattoos often pose cosmetic disturbances, they can be further uniformly distributed across the oral mucosal membranes in the form of bluish, grayish, or black macules. The common locations that can affect the patient's esthetic expectations are the mandibular or lower gingival mucosa, lips, and palate. Lesions that occur on the retromandibular area on the floor of the mouth do not usually require any treatment as they are not covered in the esthetic zones.

However, some individuals who are worried about their oral esthetics may want to undergo cosmetic surgery to eliminate the extensive amalgam tattoo. In such unacceptable cases interfering with a patient's social or cosmetic appearance, surgical excision is the recommended gold standard treatment that will be performed by your maxillofacial surgeon. After excision of the affected oral mucosa, transplantation of tissue would be done at the site, and Q-switched ruby laser or Q-switched alexandrite laser would be favorable and would likely yield favorable post-operative outcomes according to surgical research.

Conclusion

Thus, melanotic lesions, which make less, or excess melanin deposition, can be easily confused clinically with extensive amalgam tattoos. As the causes are completely different in both cases, a biopsy and microscopic examination can prove useful in detecting or confirming the right diagnosis for extensive hyperpigmentation of oral mucosa. Further, serious chronic oral lesions of hyperpigmentation from systemic diseases can also be differentiated by microscopic examination. The accidental displacement of amalgam particles into the oral mucosal tissues is the main operator-induced or iatrogenic reason for causing amalgam tattoos.