Abstract:

A 21-year-old boy had fractured his maxillary left central incisor. The fracture line involved 2/3rd of the crown, compromising the pulp and extended subgingivally on the palatal aspect invading the biologic width. The procedure used to manage this case included endodontic treatment of residual tooth, orthodontic extrusion to move the fracture line above the alveolar bone and finally the tooth was restored prosthetically.

Introduction:

Trauma with accompanying fracture of a permanent incisor is a tragic experience for the young patient and creates psychological impact on both the parents and patient. If the injury involves the loss of extensive tooth structure, it alters the patient’s appearance. This case report outlines the management of complicated crown-root fracture N873.64 [Andreasen modification of WHO classification, 1981] and Type B fracture [Dean's classification] with maintaining the healthy periodontal tissue and alveolar bone. 1-2

Case description:

A 21 year old male patient reported to post graduate clinics of department of endodontics and conservative dentistry with a complain of pain and grade 1 mobility with upper anterior teeth and with a history of roadside injury 23 hour before. Clinical examination revealed oblique fracture line on tooth no. 21, 2 mm supragingivally on the labial aspect and extending palatally towards the coronal third of root. The tooth was tender and the fractured coronal segment was mobile. It was attached only by periodontal ligament fibers on palatal side. The gingiva around the fractured tooth was inflamed on palatal aspect. Radiographic examination confirmed the findings of the clinical examination; the fracture line on palatal side could be traced 2 mm below the alveolar crest. Periapical view showed closed apex with tooth no. 21. The periodontal space around the tooth was widened. There was no damage to adjacent teeth.

On the basis of clinical and radiographic findings, a diagnosis of complicated crown-root oblique fracture, Dean's type B [plane of fracture angled cervically in a facial-to-lingual direction when viewed proximally] was made.

Treatment plan:

A detailed explanation about the treatment plan given  to the patient, which include active repositioning of intruded tooth 21 using fixed orthodontia with completion of the endodontic treatment as soon as possible. Surgery kept as a last resort. The treatment plan was accepted by the patient. Removal of fractured fragment under local anesthesia followed by single sitting  endodontic therapy of residual tooth done. After this orthodontic bracket were bonded  to anterior teeth from canine to canine to move the fracture line 3 mm above the alveolar crest was planned to regain the lost biologic width.  

At the end of 3 weeks the bracket was in contact with the horizontal wire and fracture line on palatal aspect could be seen. At this stage, circumferential supracrestal fibrotomy was performed for prevention of relapse. 3 It was now stabilized for 8 weeks by ligating brakets and horizontal wire with ligature wire. 4
The bony and periodontal repair was evident within 8 weeks. After 8 weeks, beggs brackets, straight wire, ligature wire were removed and a fiber-optic post [Luscent Anchor, Dentatus] was cemented with dual cure composite resin cement and a core was built up with composite resin. Finally the tooth was restored prosthetically for good esthetic results .

Discussion:

There are several options for the treatment of tooth fracture involving the biologic width which include Tooth extrusion, fragment reattachment only, fragment reattachment or reconstruction after crown lengthening and tooth extraction in severe case. Tooth restored with adhesive reattachment cannot withstand functional and orthodontic forces until prosthetic rehabilitation is performed; hence it cannot be considered a durable treatment.5 In the present situation, the subgingival location of the fracture line could not allow an optimal sealing besides oral hygiene could have been difficult to maintain. In such a case, two main factors must be addressed; the fracture margin access and the possibility of performing a tight seal restoration. 6

An orthodontic extrusion of fractured tooth will maintain the periodontal tissues at the same level and restore a physiological attachment. A 3-4 mm distance from the alveolar crest to the coronal extension of the remaining tooth structure has been recommended for optimal periodontal health. 7 This treatment is preferred over crown lengthening which removes alveolar bone and may become the reason for pocket formation. The orthodontic procedure allows the movement of the fracture line supragingivally and then optimizes the marginal sealing. The forced eruption was limited to 3 mm (it should be maximum 5 mm as suggested by Ingle) 4 and was achieved with minimal force (Only 0.2 - 0.3 N). 7 The major limitation of this treatment is the longer duration of treatment and a longer stabilization period. It may also impair good esthetic resolution because the cervical diameter of extruded tooth is smaller than the adjacent teeth. 8
When the tooth is moved to the new position, the supracrestal gingival fibers tend to stretch and may become the major cause of relapse. A circumferential suprecrestal fibrotomy was performed to avoid such an occurrence when the tooth was in new corrected position.Finally, the use of a fiber-optic post gives good esthetic results and increases retention and distributes the stresses along the root.

Conclusion: advanced technology and procedure not only helped in managing the difficult cases with simplicity but have also improved endodontic outcome and predictability. Restoration of traumatized teeth requires a close collaboration between the different dental fields to avoid loss of tooth. Even though orthodontic extrusion reduces crown/root ratio and widens the embrasure, this approach allows to maintain the biologic width and optimizes the marginal sealing. 6

The present case reports a multidisciplinary management of a dental trauma that leads to conservation of a tooth and its permanent restoration. In addition, the adjacent teeth need not be prepared for fixed prosthesis and the alveolar bone is conserved.

References:

1. Rao A Principles and practice of pedodontics. 1st ed, Jaypee Brothers Medical Publishers (P) Ltd New Delhi; 2006.
2. Trushkowsky RD. Esthetic, biologic and restorative considerations in coronal segment reattachment for a fractured tooth: A clinical report. J Prosthet Dent 1998; 79:115-9.
3. Carranza FA, Newman MG. Clinical periodontology. 8th ed,  A Harcourt Publishers International Company.
4. Ingle JI, Bakland LK.  Endodontics. 5th ed, BC Decker Inc.
5. Cengiz SB, Kocadereli I, Gungor HC et.al. Adhesive fragment reattachment after orthodontic extrusion: A case report. Dent Traumatol  2005; 21:60-4.
6. Villat C, Machtou P, Naulin-Ifi C. Multidisciplinary approach to the immediate esthetic repair and long term treatment of an oblique crown-root fracture. Dent Traumatol  2004; 20: 56-60.
7. Kocadereli I, Tasman F, Guner SB. Combined endodontic-orthodontic and prosthodontic treatment of fractured teeth. Case report. Aust Dent J 1998; 43:28-31.
8. Nogueira Filho Gda R, Machion L, Teixeira F B et.al. Reattachment of an autogenous tooth fragment in a fracture with biologic width violation: A case report. Quitessence Int 2002;33:181-4.