Use of orthodontic treatment as an aid to third molar extraction: A method for prevention of mandibular nerve injury and improved periodontal status

Background: Impaction of mandibular third molars predisposes to pathological conditions including periodontal disease. Extraction of these teeth also may lead to damage to the nerve and to periodontal involvement of the second molars. This report describes a series of cases in which the third molars were orthodontically induced to erupt to prevent the sequelae associated with extraction. Methods: Impacted mandibular third molars in 18 patients were surgically exposed following placement of an orthodontic appliance. Depending on the individual case, 1 of 3 approaches was used: attachment of a bracket, placement of a post in the root canal, or placement of an orthodontic wire through a bucco-lingual canal. After suturing the mucoperiosteal flap, the orthodontic appliance was activated. After the tooth erupted, it was removed and periodontal parameters were measured on the second molar. Results: No damage to the inferior alveolar nerve was found. Probing depths on the second molar were reduced from 7.9 ± 1.6 mm on the buccal and 7.4 ± 1.0 mm on the lingual to 1.8 ± 0.7 mm and 1.9 ± 0.7 mm, respectively. There was an average gain of 5.0 mm in attachment. Keratinized tissue increased from 2.9 ± 0.7 to 3.8 ± 0.6 mm. Conclusions: The interdisiplinary use of periodontics and orthodontics results in non-surgical removal of impacted mandibular third molars without damage to the inferior alveolar nerve and iatrogenic periodontal sequelae to the second molars.