“…Oral pigmentation (Table 2) is associated with a variety of exogenous and endogenous factors including drugs, heavy metals, genetics, endocrine disturbances (Addison's disease), syndromes (Albright syndrome, Peutz-Jegher syndrome), and postinflammatory reactions. 110 Physiologic pigmentation is usually symmetric, occurring on the gingiva, buccal mucosa, hard palate, lips, and tongue.…”