<unk>  is the pathological fusion between alveolar bone and the cementum of teeth, which is a rare phenomenon in the deciduous dentition and even more uncommon in permanent teeth.<unk>  occurs when partial root resorption is followed by repair with either cementum or dentine that unites the<unk>  root with the alveolar bone, usually after trauma. However, root resorption does not necessarily lead to<unk>  and the causes of<unk>  remain uncertain to a large extent. However, it is evident that the incident rate of<unk>  in deciduous teeth is much higher than that of permanent teeth. Risk factors of<unk>  can be generally classified into genetic factors and dental trauma. Diagnostic methods of<unk>  include the use of clinical examinations, x-ray and cone beam computerized tomography (CBCT).<unk>  could have several symptoms, with decreased<unk>  count being the most prominent one. Factors like gender and sex may also lead<unk> e incidence of certain signs, yet the full mechanisms have not been well evaluated. In general, the non-growing subjects and growing subjects would exhibit different signs and symptoms. Individuals suffering from<unk>  of deciduous teeth risk of losing these teeth due<unk> e failure of the<unk>  eruption during facial growth and would lead to a series of functional and esthetic problems. After diagnosis with clinical examination or CBCT image,<unk>  is often treated by removing the crown of the affected<unk> . Early orthodontic interception is also confirmed to be effective in promoting the recovery of the lost space as well as allowing the eruption of the teeth. It is current under the investigation of its probability being used as a prevention of<unk> .
Tooth ankylosis
Radial dysplasia
Metaphyseal dysplasia
Multiple epiphyseal dysplasia
Spinal stenosis
Carpal coalition
Fibrous ankylosis
Tarsal coalition