that cantilever resin-bonded bridges are at least as good as conventional fixed-fixed bridges. Restoring teeth with this method can only be done after orthodontic treatment and will need an element of retention to ensure that tooth contacts are not misplaced. Conventional bridges: Teeth tend to be prepared for conventional bridgework if there are large restorations present, thus being more commonly done on adult patients with hypodontia. Treatment with conventional bridgework will require significant reduction of tooth structure, which will put the tooth at risk of biological damage i.e. loss of vitality. This risk is especially high in young patients with large pulp chambers. Tooth autotransplantation Autotransplantation involves the removal of a tooth from one socket and relocating to another socket in the same individual. If done successfully, it is able to ensure stable alveolar bone volume as there is continuous stimulation of the periodontal ligament. Implant supported tooth replacement Placing dental implants has proven to be a predictable and reliable method of treating hypodontia, along with bringing excellent aesthetic results. Implant placement should be delayed until jaw growth in an individual is complete. One limitation of implant placement would be the need for a sufficient amount of bone volume, which if not met, may affect the positioning of the implant. However, bone grafting can be carried out to overcome this. Epidemiology Hypodontia is less common in the primary dentition, with reported prevalence rates ranging from 0.5% in the Icelandic population to 2.4% in the Japanese population. In the primary dentition the teeth reported as most likely to be missing are the lateral incisors, both maxillary and mandibular. If a deciduous tooth is missing this will increase the risk of an absent successor. In the permanent dentition third molars are most commonly absent, and one study found prevalence rates of between 20–22%. When third molars are ignored the prevalence rate for each tooth varies from study to study. In Caucasian studies mandibular second premolars and maxillary lateral incisors are most often absent. Several UK studies have found the lower second premolar to be most commonly absent. Studies from Asian populations report that the mandibular incisor is most commonly absent. A higher prevalence of hypodontia in females has been reported. The most extensive studies have been in Caucasian populations and suggest a prevalence of 4–6%. One study looked at 33 previous studies with a sample size of 127,000, and concluded that the