Failure of maxillary incisor teeth eruption usually presents around the ages of 7-9 years. The anterior maxilla is a common site for the development of supernumeraries/odontome and permanent maxillary incisors are susceptible to dilacerations and eruption failure following trauma.

Maxillary central incisors are the third most commonly impacted tooth after third permanent molars and maxillary canines. Failure of eruption are often associated with other dental anomalies such as enamel hypoplasia, supernumerary teeth (most frequently) and ectopic teeth.

Establishing The Cause Of Eruption FailureClinical FeaturesPatient Factors To Consider When Treatment PlanningDental Factors To Consider When Treatment PlanningManagement OptionsTreatment Of Ankylosed Maxillary IncisorsRefernces
  • Determine any possible hereditary or environmental factors which may have caused delayed eruption.
  • Trauma is a major cause of the failure of eruption of a maxillary incisor, therefore any trauma should be sought and documented as accurately as possible.
  • Spacing and rotations
  • Displacement of permanent teeth in the upper anterior segment
  • Presence of palatal/labial swelling
  • Angulation and inclination of adjacent teeth
  • Availability of spacing:
    • 9mm– central incisor
    • 7mm– lateral incisor
  • Medical history
  • Age
    • According to RCS guidelines the spontaneous eruption of un-erupted maxillary incisor is more likely to occur following the removal of any associated supernumerary between the ages of 8-9.
  • Patient compliance
  • Retained primary teeth
  • Position of impacted incisor
    • The higher the vertical position of the impacted maxillary incisor the less likely it is to erupt spontaneously.
  • Developmental stage of impacted incisors
    • Some studies report, un-erupted incisors with immature roots are more likely to erupt spontaneously following supernumerary removal than those with mature roots.
  • Unfavourable root formation
    • Dilacerated roots- can be due to environmental or developmental factors

1) Removal of physical obstruction (eg. Supernumerary or odontome) only

Patient criteria: Children up to 9 years with incomplete root development of permanent incisor.

  1. Remove obstruction
  2. Do not uncover bone from the un-erupted incisor
  3. Monitor eruption for up to 12 months- many incisors will erupt spontaneously
  4. If exposure is required, then expose minimally to eliminate soft tissue obstruction.
  5. If the tooth is still high, expose and bond bracket

2) Removal of the obstruction alongside creation of space

Patient criteria: Children above 9 years with complete or nearly complete apex

  1. Remove obstruction
  2. Create space of required
  3. Permanent incisor can be monitored for up to 12 months
  4. If the tooth is un-erupted at 12 months, or if the incisor is high at the time of removal of an obstruction, expose and bond bracket as required.

3) Surgical Intervention

Patient criteria: If the permanent incisor is impacted or children referred who are older than 10 years old.

Open Exposure:

  • Simple elliptical incision of the overlying soft tissue, may be useful when there is a soft tissue impaction, with the tooth occupying a very superficial position just beneath the mucosa.
  • When the vertical height of the un-erupted incisor precludes a simple soft tissue excision over the crown of the tooth, an apically repositioned flap can be used to expose the crown of the tooth. This technique has been associated with increased incisor crown length and poor aesthetics.

Closed Eruption Technique:

  • A mucoperiosteal flap incorporating the attached gingiva is raised and an attachment bonded to the impacted incisor before the flap is replaced into its original position.
  • The attachment should incorporate a gold chain or traction ligature. The attachment should be low profile and bonded to the palatal surface of the unerupted incisor.

4) Incisor removal

Sometimes a permanent maxillary incisor has to be removed due to significant dilacerations/ ankylosis/ infra-occlusion. Space should be maintained for subsequent replacement.

5) Auto transplantation

NOTE: If the permanent incisor is impacted

Potential risks of treatment:

  • Failure of eruption
  • Ankylosis
  • External root resorption
  • Poor gingival aesthetics
  • Leave and monitor with a possible composite build-up for any minor infra-occlusion
  • Reposition the ankylosed incisor eg. Surgical dislodgement, repositioning osteotomy or distraction osteogenesis
  • Extraction of the ankylosed incisor followed by orthodontic space closure or prosthetic replacement
  • De-coronation of the incisor

Bjerklin K, Kurol K. Ectopic eruption of the maxillary first permanent molar: Etologicfactors. American Journal of Orthodontics 1983;84: 147-155.

Barberia-Leache E, Suarez-Clua MC, Saavedra-Ontiveros D. Ectopic eruption of the maxillary first permanent molar: characteristics and occurrence in growing children. Angle Orthodontist 2005;75: 610-615.

Pulver,F.The etiology and prevalence of ectopic eruption of the maxillary first permanent molar. ASDC Journal of Dentistry for Children 1968;35:138–146.

Bjerklin, K.Ectopic eruption of the maxillary first permanent molar. An epidemiological, familial, etiological and longitudinal clinical study.Swedish Dental Journal Supplement 1994;100:1–16.

See also Anterior Open Bite