During the period of tooth replacement in children, whether the incisors erupt properly is often one of the greatest concerns for parents. In some cases, a child’s tooth may fail to erupt on time. This is not always due to delayed development—it may indicate an obstruction to normal tooth eruption.

Xiao-An, a 7-year-10-month-old child, visited the pediatric dental clinic accompanied by his mother. The chief complaint was that his upper left front tooth had not erupted. The parents were worried, and the child felt self-conscious about smiling due to the missing tooth. The parents reported that the right central incisor had already erupted, but the left side showed no signs of eruption, prompting them to seek further evaluation.

Eruption Disturbance of Incisors

Generally, the maxillary central incisors erupt between the ages of 7 and 9. If one incisor has erupted for more than six months while the contralateral tooth has not, an eruption disturbance should be suspected.

Upon examination, Xiao-An was diagnosed with a typical eruption disturbance of the incisor. His facial proportions were generally normal, with no signs of midface deficiency. The lips were in an ideal position, and the facial profile appeared balanced.

There are many possible causes of eruption failure, including supernumerary teeth (accounting for 42–62% of cases), severe tooth displacement, cysts or odontomas causing impaction, retained primary teeth, root dilaceration or ankylosis, and excessively thick gingival or periodontal tissue.

Clinical and radiographic examinations revealed that Xiao-An had an odontoma located beneath the upper left central incisor, blocking its normal eruption path—this represents a localized pathological factor. Space analysis also showed that there was only about 8 mm of space available in the upper left incisor region, whereas studies suggest that at least 9 mm is typically required for eruption of a central incisor. Therefore, insufficient space was also a contributing factor.

A preoperative cone-beam computed tomography (CBCT) scan was recommended to confirm the position. Under general anesthesia, the odontoma was surgically removed, and local orthodontic treatment (2×3 appliance) was used to create space. The plan was to observe for one year to allow for possible spontaneous eruption of the permanent tooth.

Unfortunately, even after removal of the odontoma and space creation, the tooth did not erupt spontaneously. After discussion with the parents, a more active combined surgical and orthodontic approach was chosen.

Closed Eruption Technique

Due to the deep position of the impacted upper left incisor, a closed eruption technique combined with orthodontic treatment was performed.

Studies suggest that the closed eruption technique results in better gingival height, periodontal condition, and pulp vitality. In contrast, the open eruption technique may lead to longer clinical crowns and reduced bone support.

During surgery, the gingiva was reflected, and a stainless steel chain was bonded to the surface of the impacted tooth and connected to the main orthodontic archwire. The gingiva was then repositioned and sutured. Orthodontic forces were subsequently applied to gently and continuously guide the tooth downward.

After eruption, further orthodontic techniques were used to adjust the tooth’s position and angulation. Initial alignment was achieved using small-diameter nickel-titanium wires, followed by stainless steel wires for more stable control. A “double force system” was also employed, applying both main and auxiliary forces to ensure proper angulation and direction during traction. Finally, gingival recontouring was performed to achieve a more natural appearance.

At the completion of treatment, Xiao-An’s incisor successfully erupted and aligned properly. The occlusion was stable, the appearance was natural, and there was a healthy amount of keratinized gingiva and bone support. Both the patient and his parents were very satisfied with the outcome.

Advice from Pediatric Dentists

Early orthodontic treatment in children is generally considered interceptive orthodontics. Its purpose is to intervene during the mixed dentition stage (approximately ages 7–11), taking advantage of the plasticity of skeletal growth to guide dental and jaw development. Unlike adult orthodontics, the goal is not necessarily to achieve perfect tooth alignment and jaw relationships.

In addition to eruption disturbances, early orthodontic treatment can address issues such as guiding jaw growth, correcting anterior and posterior crossbites (to prevent jaw asymmetry), managing severe protrusion or deep bite (to reduce the risk of trauma to front teeth), expanding the dental arch to create space for permanent teeth, and correcting harmful oral habits that may affect jaw development.

However, orthodontic treatment typically takes a long time (1.5–2 years) and may be uncomfortable. In more complex cases requiring conventional braces, maintaining oral hygiene can also be challenging. Children need sufficient motivation to complete treatment successfully, which requires cooperation among the child, parents, and dentist.