Table 1 Selection criteria

Inclusion criteria

 Subjects must provide written informed consent prior to performance of study, specific procedures or assessments and must be willing to comply with treatment and follow-up

 Second molar impaction or primary retention (maxilla or mandible)

 Initial records with CBCT

 Surgery done with the mechanics of the miniscrew-supported pole technique. These patients must present at least three of the following indications:

  Older than 14 years old

  Vertical, distal, or mesial M2 angulation ≥ 45°

  Severe bone depth of the M2

  Proximity to the inferior alveolar nerve canal or the maxillary or mandibular cortical bone

  Closed apex

  Alteration of the root apex

  Signs of primary M2 retention like increased dental follicle

  Previously unsuccessful surgical exposure

Exclusion criteria

 Patients with existing periodontal disease (patients with bleeding on probing, pocket depths > 3 mm and decreased bone diagnosed from baseline radiography)

 Complicated medical or social history where surgery, orthodontic treatment or periodontal probing may be contraindicated and /or syndromic patients

 Age > 25 years