Eruption problems frequently noted and covered in this section are:
An eruption hematoma presents as a bluish swelling over an erupting tooth and is usually asymptomatic. The follicle surrounding the erupting tooth becomes filled with blood-tinged fluid. Eruption hematomas usually rupture spontaneously and require no treatment. Treatment is indicated when eating is impaired by the size of the hematoma or if pain is present.
Over-retained Primary Teeth
Primary teeth may be retained beyond the normal exfoliation time. One reason for "over-retention" is the lack of a permanent successor. Another cause of retention is ankylosis, a condition in which the root surface becomes fused to the alveolar bone. The primary teeth most commonly ankylosed are the mandibular primary first and second molars, followed by the maxillary primary first and second molars. For some patients, extraction of the ankylosed tooth may allow for the eruption of a succedaneous tooth. Bruxism has also been identified as a factor in over-retention of primary teeth.
Disturbances in Exfoliation/Eruption
Ectopically erupting permanent teeth follow an abnormal path. This may cause either premature root resorption and early loss of erupted primary teeth or the opposite, when root resorption does not occur and primary teeth are retained. Ectopic eruption may be associated with any tooth. Crowding may be seen in the lower anterior region when the permanent incisors erupt lingual to the primary incisors.
Early or Late Loss of Primary Teeth
Early or late loss of primary teeth is sometimes associated with systemic conditions. Cleidocranial dysostosis, Trisomy 21 (Down Syndrome), hypothyroidism, and hypopituitarism are conditions associated with retention of primary teeth. Conditions associated with premature exfoliation are hypophosphatasia, Langerhans cell histiocytosis, hyperthyroidism, and cyclic neutropenia.