Orthodontic extrusion By : hoda pouyanfar

Orthodontic forced eruption may be a suitable approach without risking the esthetic appearance in tooth fracture below the gingival attachment or alveolar bone crest. Extrusion of such teeth allows elevating the fracture line above the epithelial attachment and so the proper finishing margins can be prepared. Restoration after orthodontic eruption may present a more conservative treatment choice in young J Can Dent Assoc 2004; 70(11):775–80

Orthodontic Extrusion Movement of a tooth by extrusion involves applying traction forces in all regions of the periodontal ligament to stimulate marginal apposition of crestal bone. Because the gingival tissue is attached to the root by connective tissue, the gingiva follows the vertical movement of the root during the extrusion process. Similarly, the alveolus is attached to the root by the periodontal ligament and is in turn pulled along by the movement of the root. J Can Dent Assoc 2004; 70(11):775–80

Indications for Orthodontic Extrusion for treatment of a subgingival or infraosseous lesion of the tooth between the cementoenamel junction and the coronal third of the root (caries, oblique or horizontal fractures, perforations caused by a pin or Post , internal or external root resorption), especially when there are esthetic considerations for treatment of a restoration impinging on the biological width for reduction of angular bone defects and isolated periodontal pockets for preimplant extraction to maintain or re-establish the integrity of an alveolar ridge for orthodontic extraction where surgical extraction is contraindicated (chemotherapy or radiotherapy) for treatment of trauma or impacted teeth(canines) J Can Dent Assoc 2004; 70(11):775–80

J Can Dent Assoc 2004; 70(11):775–80

Contraindications to Orthodontic Extrusion ankylosis or hypercementosis root proximity and premature closure of embrasures short roots insufficient prosthetic space exposure of the furcation. the presence of chronic, uncontrollable inflammatory lesions, including combined endodontic-periodontic lesions and fractured roots; an inability to control inflammation and acute infection that would adversely affect healing and the overall response to treatment an absence of attachment apparatus because forced eruption only relocates the existing attachment, it does not create a new attachment J Can Dent Assoc 2004; 70(11):775–80

J Can Dent Assoc 2004; 70(11):775–80

Advantages conservative procedure that allows retention of a tooth without the disadvantages of a fixed bridge does not involve loss of bone or periodontal support, as commonly occurs during extraction Avoid resection of bone of the teeth adjacent to the tooth this simple technique requires a relatively easy movement of the tooth. J Can Dent Assoc 2004; 70(11):775–80

Disadvantages Wearing an orthodontic device esthetic problems oral hygiene duration of treatment (4 to 6 weeks of extrusion and 4 weeks to 6 months of retention for implant cases in which tissue and bone remodelling are the objectives) periodontal surgery J Can Dent Assoc 2004; 70(11):775–80

Periodontal Effects Orthodontic extrusion forces coronal migration of the root and increases the bone ridge as well as the quantity of attached gingiva , in particular when weak to moderate forces are applied. The amount of attached gingiva is increased through eversion of the sulcular epithelium, appearing first as immature nonkeratinized tissue (known as“red patch”) and then as keratinized tissue; the process of keratinization requires 28 to 42 days. J Can Dent Assoc 2004; 70(11):775–80

J Can Dent Assoc 2004; 70(11):775–80

After coronal movement of the periodontal attachment J Can Dent Assoc 2004; 70(11):775–80 After coronal movement of the periodontal attachment minor surgical correction weekly fibrotomy single fibrotomy

J Can Dent Assoc 2004; 70(11):775–80

Extrusion and Endodontics Treated endodontically to prevent sensitivity and exposure of the pulp during the occlusal reduction required during the extrusion. calcium hydroxide Pulpectomy extrusion force of 50 g preimplant extraction 1 week odontoblastic degeneration 4 weeks J Can Dent Assoc 2004; 70(11):775–80 pulpal fibrosis

Pulp prolapse would be due to ischemia secondary to rapid movement J Can Dent Assoc 2004; 70(11):775–80 pulpal reaction would differ depending on the diameter of the apical foramen Pulp prolapse would be due to ischemia secondary to rapid movement During rapid extrusion, a pseudo-apical lesion appears, which must be differentiated from a true lesion of endodontic origin

Extrusion and Prosthodontics The mesiodistal diameter of the root, which is naturally “strangled” at the cementoenamel junction of single-rooted teeth, is reduced with progression of the extrusion (especially in the case of conical roots), which involves expansion of interproximal gingival embrasures. The contour shape of the crowns must not be exaggerated to compensate for this reduction in diameter . Similarly, embrasures should not be filled to prevent an overcontour, which could adversely affect the marginal periodontium. J Can Dent Assoc 2004; 70(11):775–80

J Can Dent Assoc 2004; 70(11):775–80

Choice of treatment 37 teeth re-eruption with forceps at the day of the injury and splinted with wire and composite for 2–6 weeks 7 teeth Repositioned orthodontically (two teeth within 1 week and five teeth after 1–8 months) 7 teeth

Results Re-eruption occurred in 35 out of 37 teeth 2 teeth → ankylosis both necrosis and the external root resorptions occurred more often in orthodontically and surgically repositioned teeth than in the non- repositioned teeth

Condition 5 days after injury, before start of endodontic treatment. A gingivectomy was performed to gain access to the root canal Partial re-eruption 1 month later. Pulp canal is filled temporarily with calcium hydroxide Complete re-eruption and permanent root filling 10 months after trauma

Three weeks after complete intrusion Five years later

20-year-old male

The total extrusion time was 4 months. The extruded tooth was retained with the same arch wire for 12 weeks to prevent any relapse. At the end of a 12-week retention period, gingivectomy and fiberotomy were performed for lingual margin exposure and better esthetics.

A 21-year-old white woman

complicated crown fracture in central oblique crown-root fracture in lateral

A temporary root canal therapy using a calcium hydroxide dressing was immediately performed on both incisors, which were then sealed with a glass ionomer cement

9-year-old child cervical root fracture Calcium hydroxide pulpotomy for apexogenesis

extrusion of 2–3 mm was obtained within 6–8 weeks

The patient was examined every 3 months during the follow-up period of 18 months

After 3-year follow-up

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