Dental ankylosis is a condition characterized by abnormal fusion of the cementum of the tooth
with the surrounding alveolar bone, leading to the loss of the periodontal ligament (PDL). This
fusion disrupts the normal tooth eruption process, especially in primary teeth, and prevents
them from reaching the correct occlusal plane. The exact cause of ankylosis in primary teeth is
not fully understood and is the subject of ongoing research. However, it is believed to be mul-
tifactorial, including potential contributing factors such as trauma, genetic predisposition, bone
disorders, systemic diseases, and infections. Research shows that ankylosis predominantly affects
the first lower primary molars, with secondary ankylosis sometimes occurring due to traumatic
events. Following the first lower primary molars, the first upper primary molars, second lower
primary molars, and second upper primary molars are also frequently affected. Infra-occlusion
is approximately 10 times more common in the mandible than in the maxilla and often occurs
bilaterally. Clinically, ankylosed teeth cannot be exposed to post-eruption movements and can
remain fixed in the infra-occlusion position. The severity of infra-occlusion can vary from mild to
complete retention. Histological examinations of ankylosed teeth reveal that resorbed root areas
may be replaced by both cementum and bone, establishing a direct connection between the
tooth and the surrounding bone. In addition, PDL remnants may be present despite fibrosis and
reduced cell number. Treatment goals for infra-occluded primary molars with successive teeth
include facilitating the natural eruption of the permanent tooth while protecting the affected
tooth and surrounding gum and bone tissue. The goals in the treatment of ankylosed teeth are
to preserve the affected tooth as much as possible, protect adjacent tissues, prevent interference
with normal growth, enable orthodontic interventions, preserve the aesthetic appearance, and
restore normal function.