Pigmentation in the oral cavity

When examining the oral cavity, the doctor may encounter unusual discoloration on the mucous membranes. This can be a harmless discoloration, but also a consequence of a serious disease. Therefore, every doctor should examine such a finding carefully.

Pigments
Pigments can be divided into exogenous - from the external environment and endogenous - from the internal environment, depending on where they are obtained. A common example of exogenous pigmentation is the amalgam tattooing of the gums. Endogenous pigments include the breakdown products of blood dye and melanin, which, among other things, determines skin colour.

Endogenous pigments
They come from the inner environment.

Physiological pigmentation
This type of pigmentation is most commonly seen on the mucous membranes of the cheeks and gums, but can also be seen elsewhere. They tend to be symmetrical. There is no need to treat them, just monitor them. They are more common in dark-skinned individuals.

Melanotic macules (mucosal melanosis)
Melanotic macules are tiny spots in the red lip area. Their size does not exceed 1 cm in diameter. They occur in the fifth decade of life, they are harmless, there is no need to deal with them clinically. They can also occur on the mucous membranes of the oral cavity, this is due to hyperpigmentation of the basal epithelial cells and multiplication of melanophages.

Smoker's melanosis
Substances contained in cigarette smoke have the ability to activate the proliferation of melanocytes. Spots are found mainly on the cheeks, gums and palate. The good news is that if a smoker stops smoking, the discoloration of the mucous membranes will disappear.

Nevocellular nevi
They can be congenital or acquired and pose a risk of malignant reversal, so it is important to monitor them carefully.

Malignant melanoma
One of the most dangerous tumours, malignant melanoma, can develop in the oral cavity. It arises de novo or as a result of malignant degeneration of a nevus. It accounts for about half a percent of all oral cavity tumours and is not very common in the Czech Republic. Melanoma most often develops on the palate.

Melanin pigmentation in general diseases



 * Peutz-Jeghers syndrome

Small pigmentations are found on the lip blush, but also on the skin around the lips. This syndrome is associated with the presence of a large number of polyps in the intestine, so these patients are more at risk of developing colorectal cancer.


 * Addison's disease

In this disease, an excessive amount of melanin is produced. The hyperpigmentation is mainly in the genital area and areola mammae. In the oral cavity, patches of grey-black pigmentation (called graphite spots) develop on the oral mucosa, especially on the facial mucosa in the region of the molars and on the sides of the tongue.

Haematogenic pigments
These are pigments that are formed by the breakdown of blood dye. Haematogenous pigmentation occurs, for example, in trauma when a patient bites his face (for example, after anaesthesia). Other examples are hematomas, ecchymosis, purpura. A rare cause of pigment deposition of haematogenous origin is haemochromatosis, which is a hereditary disease manifested by increased iron deposition in the body. The manifestation of this disease in the oral cavity is gray-blue pigmentation of the palate and mucous membranes of the cheeks.

Exogenous pigments
They come from the outside environment.

Amalgam
Amalgam stains the gingiva during iatrogenic infection, when amalgam particles from a drilled filling enter the open wound in the gingiva. However, staining can also occur galvanically or traumatically. The discoloured deposits are most often on the gums, cheeks, etc.

Heavy metal poisoning
The black border on the gum is caused by lead poisoning.

Medications
Cisplatin, which is used in cancer therapy, causes the so-called platinum stripe.

Other causes
Other causes include, for example, voluntary tattooing (chewing herbs) or being struck by a foreign body - the tip of a pencil, etc.

Related articles

 * Pigment
 * Addison's disease
 * Lead poisoning
 * Amalgam

Literature used

 * HOLLÁ, Lydie a Antonín FASSMANN. Repetitorium onemocnění sliznice ústní dutiny: (vybrané kapitoly). 1. vyd. Brno: Masarykova univerzita, 2003, 82 s. ISBN 80-210-3047-x.
 * LIŠKA, Karel. Orofaciální patologie. 1. vydání. 1983.


 * POVÝŠIL, Ctibor a Ivo ŠTEINER, et al. Obecná patologie. 1. vydání. Praha : Galén, 2011. 290 s. ISBN 978-80-7262-773-8.


 * DUNDR, . Dutina ústní [přednáška k předmětu Patologická anatomie, obor Zubní lékařství, 1. lékařská fakulta Univerzita Karlova]. Praha. 11.11.2013.