Hypodontia is a developmental dental anomaly defined as the absence of one or multiple teeth, not including the third molars. The condition can affect permanent and primary dentition and is the most common developmental dental anomaly. Hypodontia is characterised by a patient presenting with fewer teeth than normal, with more than six missing teeth classed as a severe case of the condition. Anodontia is when all teeth are completely absent.
Deciduous teeth are the first set of teeth in childhood and are temporary before the natural emergence of adult or permanent teeth. Hypodontia of deciduous teeth typically affects upper laterals or lower central incisors, accounting for 50 to 90% of childhood cases of the condition. Orthodontics specialist Jonathan Alexander Abt has written in the American Journal of Orthodontics and Dentofacial Orthopedics on the diagnosis of apparent hypodontia.
People demonstrating permanent hypodontia are usually missing just one or two teeth, with the upper lateral incisors or 2nd premolars the most commonly affected. However, there is more variation in individuals suffering from hypodontia as part of a medical syndrome. Hypodontia is not always associated with a syndrome, although cleft-lip patients are more likely to present with the condition, especially if the cleft is severe. Other conditions which increase the likelihood of hypodontia include Down’s syndrome.
Individuals affected by hypodontia are typically concerned with the appearance of their teeth, particularly if front teeth are missing or unusually small or pointed. In more severe cases, where numerous teeth are missing, speaking and chewing may be difficult. Dental examinations and X-rays are needed in order to diagnose the condition.
There is currently no recognised way of preventing hypodontia and in some cases there will be no known reason for its occurrence. As well as affecting people with certain syndromes and other conditions, hypodontia often runs in families too. However not everyone with the condition will pass it on to their children.
Many things can be done by family dentists and orthodontic specialists to treat hypodontia. Treatment will often involve tooth replacement or reshaping existing teeth to improve appearance. Sometimes braces can be used to realign teeth so that there are no visible gaps, or they can be used to widen gaps to allow space for replacement teeth. There is currently extensive research being done to discover causes of hypodontia and develop the best treatment options.