Oral health is essential to general health and quality of life because worldwide, 60–90 per cenr of school children and nearly 100 per cent of adults have dental cavities, often leading to pain and discomfort and severe periodontal (gum) disease, which may result in tooth loss, is found in 15–20 per cent of middle-aged (35-44 years) adults.

It is a state of being free from mouth and facial pain, oral and throat cancer, oral infection and sores, periodontal (gum) disease, tooth decay, tooth loss and other diseases and disorders that limit an individual’s capacity in biting, chewing, smiling, speaking, and psychosocial wellbeing.

The most common oral diseases are dental cavities, periodontal (gum) disease, oral cancer, oral infectious diseases, trauma from injuries, and hereditary lesions. Complete loss of natural teeth is widespread and particularly affects older people. Globally, about 30 per cent of people aged 65–74 have no natural teeth. The incidence of oral cancer ranges from one to 10 cases per 100 000 people in most countries.

The prevalence of oral cancer is relatively higher in men, in older people, and among people of low education and low income. Tobacco and alcohol are major causal factors. Almost half (40–50 per cent) of people who are HIV-positive have oral fungal, bacterial or viral infections. These often occur early in the course of HIV infection.

Across the world, 16-40 per cent of children in the age range 6 to12 years old are affected by dental trauma due to unsafe playgrounds, unsafe schools, road accidents, or violence. Noma is a gangrenous lesion that affects young children living in extreme poverty primarily in Africa and Asia. Lesions are severe gingival disease followed by necrosis (premature death of cells in living tissue) of lips and chin. Many children affected by noma suffer from other infections such as measles and HIV. Without any treatment, about 90 per cent of these children die.