There are many dental and oral diseases that cause pain, swelling or other acute symptoms. Some general principles can assist medical practitioners to understand the common dental disorders, but more detailed information is available in other publications.1,2
The common dental conditions are inflammatory in nature rather than being infections. Although they are caused by the presence of bacteria in or on the tooth, the bacteria are not necessarily causing all the problems that would be seen when other tissues of the body become infected. Infections do occur in some cases and these may manifest in the form of abscesses (periapical or periodontal) or facial cellulitis.
Dental caries
The most common dental disease is dental caries or tooth decay. It can be painless, but can cause pain ranging from mild to severe pain with swelling and spreading infection. Dental caries is essentially a bacterial disease process which breaks down tooth structure. Once the tooth's outer protective layer of enamel has been breached, the bacteria can progress through the underlying dentine via its network of many tubules. Eventually, the pulp becomes inflamed and if left untreated, it will necrose as the bacteria spread further down into the tooth root. Infection of the root canal system then occurs and this leads to apical periodontitis, an inflammatory response within the periodontal ligament that surrounds the tooth root. Acute apical periodontitis is typically a very painful condition that is likely to lead a patient to seek medical or dental assistance.
Gum disease
The second most common oral condition that can lead to pain and symptoms is periodontal disease. There are various forms of periodontal disease and they are generally the result of the build-up of plaque and calculus on teeth. Plaque is a biofilm of bacteria and this causes inflammatory changes within the gingival tissues and the periodontal ligaments that support the teeth. Most of these conditions are chronic and usually do not cause pain, but some patients will develop acute conditions as a result of certain bacteria or other predisposing factors.
Other conditions
Pain can arise from aphthous ulcers, mucosal diseases (for example lichen planus, pemphigoid), trauma to the teeth or oral tissues, impacted teeth, occlusal (bite) problems, temporomandibular disorders, inflammation of the muscles of mastication, tumours and cysts. Some of these conditions are uncommon and difficult to identify. They generally do not require any emergency or urgent treatment by a medical practitioner unless the patient has severe pain. These conditions should always be assessed and managed by a dentist.