Loss of teeth. Coloured pan-oral X-ray of the mouth of an elderly man showing his few remaining teeth. Some of the teeth (for instance at centre right) have fillings (white) in them. Only one tooth remains in this man's upper jaw. Teeth can be lost due to infections of the gums (gingivitis) or the teeth themselves (caries). Good dental hygiene, such as regular brushing, can help to prevent both disorders.