Teeth are necessary for chopping food into small pieces to make digestion easier. Each person has two sets of teeth: the primary teeth, which emerge in infancy, and the secondary teeth, which gradually replace the primary teeth in late childhood. Both sets are protected from damage and decay by a hard coating of enamel and by the gums, which cover the roots.
Good oral hygiene is essential because without regular brushing and flossing of the teeth and gums, tooth decay or gum disease may develop. Improved oral hygiene and the addition of fluoride to water in many parts of the world in order to harden teeth have made tooth decay far less common today than it was several decades ago.
The first articles in this section deal with tooth disorders that are usually caused by neglect of oral hygiene, such as toothache and tooth decay. If left untreated, tooth decay may spread to the central parts of the teeth and cause pulpitis. Pus may eventually build up at the root of a tooth due to infection, resulting in a dental abscess. Poor oral hygiene can also cause teeth to become discoloured. Malocclusion caused by teeth that have grown unevenly or become overcrowded is covered in Malocclusiion. Sometimes teeth are missing or are broken or lost due to injury. Problems of the temporomandibular joint are covered in the last article of this section. Teething in babies is discussed in the children’s section.
For more information on the structure and function of teeth, see Teeth and Gums.
The gums form a layer of protective tissue that surrounds the base of each tooth and covers part of the jawbones. Healthy gum forms a tight seal around the crown of a tooth and protects the sensitive tissues below from bacterial invasion. If the gums are damaged, the teeth may become unsupported and loose. Most gum disorders can be prevented by good oral hygiene.
Most adults have some degree of gum disease which, if left untreated, may eventually lead to loss of teeth. Good oral hygiene is essential to help to prevent gum disorders. During regular dental checkups, most dentists and oral hygienists provide information on the correct way to brush and floss teeth and on general mouth care.
The first topics covered here are gum disorders such as gingivitis and periodontitis, which may be caused by poor oral hygiene. Inadequate teeth cleaning leads to a build-up of plaque (a deposit of food particles, saliva, and bacteria) on the surfaces of the teeth. If the plaque is not removed, it causes the gums to become inflamed. In more serious cases, the teeth may be affected and loosen or come out, either because the periodontal tissues are inflamed and detach from the teeth or because the gums recede, exposing the roots and leading to tooth decay. The final article in this section discusses a condition called dry socket, in which a tooth socket becomes inflamed after the tooth has been extracted.
For more information on the structure and function of the gums, see Teeth and Gums.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.