Author :.Dr.Smita Singh, Prof and HOD, Dept of Conservative Dentistry and Endodontics, Darshan Dental College, Udaipur, Rajasthan

Abstract:

Traumatic intrusion also classified as “intrusive luxation” is a type of dental injury that involves displacement of the tooth into the alveolar socket. Radiographically, the tooth is shifted in an apical direction with partial or complete disappearance of the periodontal ligament space. This type of injury usually involves the maxillary anterior teeth and is more common in the primary than the permanent dentition. A case report is presented in which a intruded tooth was successfully treated by surgical repositioning and acid etch composite splinting followed by the completion of root canal treatment. Also the use of pulse oximeter in checking the vitality of recently traumatized teeth is presented.

Introduction

In dental traumatology, the term traumatic intrusion refers to the displacement of a tooth into the alveolar bone following the application of traumatic force. More properly named intrusive luxation; it usually affects the anterior teeth and is often associated with impacted fracture of the alveolar bone 1.
Andreasen conducted a retrospective study on the etiology and pathogenesis of traumatic dental lesions and observed that, from 2239 traumatized permanent teeth, only 3.0% presented intrusive luxation 2.According to different studies, intrusion of permanent teeth is a rare injury with frequency ranging from 0.23 to 5 percent. The 6-12 years old age is the most frequently involved group in intrusion injuries, but it may also occur later in life. Boys appear to suffer from intrusion earlier than girls. There appears to be a slight difference in the sex proportion of intrusion with more frequent exposure to intrusion in males. The maxillary central and lateral incisors constitute for the majority of cases while mandibular teeth are seldom involved 3.

The clinical treatment for intrusion is especially difficult, because of the severe complications associated with it. These complications include pulp necrosis or obliteration, inflammatory root resorption, ankylosis, replacement root resorption and loss of marginal bone support 4.

Case report

A 25 years old male patient reported with intruded left maxillary central incisor. He gave history of bicycle accident 24 hours back. Extra oral examination revealed the presence of lacerations on the chin and no other signs of injury were observed.  (Figure 1.Pre operative photograph)
Intraoral examination revealed intruded tooth #21 which was firm on palpation. Intraoral periapical radiograph and OPG were taken which revealed completely formed root of tooth #21, and the incisal edge of the intruded tooth was located at the level of the crown-root interface of the adjacent tooth. Also, periodontal space was absent and there was no sign of any other alveolar fracture.

(Figure 2,3 Pre operative Radiographs)

Thermal and electric pulp testing of adjacent teeth #11, 12, 22 was done which gave no response. Since the role of thermal and electric pulp testing on recently traumatized teeth is doubtful, a pulse oximeter test was done for teeth #11, 12, 22. More than 80% oxygen saturation level was obtained and hence they were excluded out of treatment plan.

Based on the clinical and radiographic findings immediate surgical repositioning of the intruded tooth was planned. The soft tissues lacerations were sutured.
The repositioned intruded tooth was splinted physiologically using composite acid etch splinting technique. The labial enamel of the six maxillary anterior teeth was etched with 37% phosphoric acid for 30 seconds, rinsed and dried. The ligature wire was then bonded into place with composite resin. (Figure 4. Intruded tooth # 21 surgically repositioned, splinted and soft tissue sutured)

The patient was recalled after twenty four hours and root canal treatment of tooth # 21 was initiated. Pulp extirpation was done after access opening followed by the completion of biomechanical preparation and the selection of master cone gutta percha.

Calcium Hydroxide as an intra canal medicament was placed and Cavit-G was used as temporary restorative material. The patient was recalled after four weeks.  At four weeks appointment obturation was completed and the splint was removed.

Pulse oximeter gave normal oxygen saturation levels of teeth #11, 12, 22. These teeth now tested positive with EPT also. Further follow up radiograph at two year post operatively showed normal healing of the periapical area without any sign of resorption.

(Figure 5. Post operative IOPA radiograph showing obturated tooth #21)
(Figure 6. Post operative photograph after splint is removed)
(Figure 7. Follow up Intraoral periapical radiograph after 2 years)

Discussion:

Andreasen 5 observed 100.0% of pulp necrosis in intruded teeth with closed apices and 62.5% in teeth with incomplete root formation. Thus, endodontic intervention should be initiated as early as possible to prevent inflammatory external root resorption.

In the present case endodontic treatment was initiated twenty four hours after surgical repositioning and splinting to avoid the chances of inflammatory root resorption which is very high in intrusive luxation injuries.

Different methods have been advocated in the literature for the treatment of intrusive luxation, and there is disagreement as to the most favourable means to reposition the intruded tooth.

The techniques include allowing spontaneous reeruption (passive repositioning), immediate surgical repositioning followed by splinting, and orthodontic repositioning 6-7.

The term spontaneous eruption suggests a false optimistic impression, as movement of the tooth after trauma, besides being unpredictable, also behaves differently from the normal eruption pattern.

Another imprecise term is the orthodontic repositioning. The traction forces used to move intruded teeth are higher than those applied in conventional orthodontic treatment. Severely intruded teeth do not have a functional periodontal ligament, which is a requirement for orthodontic movement. These terms suggest that an intruded tooth will return to its original position with time, or will be moved from the intrusion position by the same mechanisms employed in conventional orthodontic treatment. None of these assumptions is necessarily true8.

Therefore, the strategies of treatment for intruded teeth include surgical reduction (immediate repositioning), allowing the tooth to return to its original position (passive repositioning), or repositioning with traction (active repositioning).

However, surgical repositioning has been associated with a high incidence of ankylosis, pulp necrosis and marginal bone loss4 but according to Ebeleseder et al6 an advantage of the surgical technique is that it may be easily performed; moreover, it returns the adjacent tissues to the original anatomic situation to allow repair and further allows fast and adequate endodontic access. However, the inadvertent exarticulation during repositioning and the possibility of additional damage to the periodontal ligament lead to an increased risk of ankylosis.

Therefore, the short comings of the surgical repositioning treatment procedure would be more dependent on the clinicians skill than on the procedure itself.
Cunha et al9 also agreed that immediate surgical repositioning of severely intruded permanent teeth with complete root formation presents several advantages and few disadvantages.

In this case surgical repositioning was preferred over orthodontic repositioning which is in accordance with the treatment guide lines of intruded teeth as given by British society of pediatric dentistry13 (BSPD) and Andreasen et al14 depending on the root apex formation and the degree of intrusion.

(here PR= Passive reeruption,  SR= Surgical repositioning and OR= Orthodontic repositioning)

With regard to the intra canal medicament of choice, calcium hydroxide has been shown to successfully stop the inflammatory resorption 1,10.
Although some studies suggest a harmful effect of calcium hydroxide on the periodontal ligament, which might supposedly lead to localized ankylosis and replacement resorption.11 However, a review of the clinical investigation that evaluated the long term prognosis of intruded teeth treated with calcium hydroxide does not support this theory 10,12. The ankylosis caused by damage to the periodontal tissues occurs before treatment with calcium hydroxide, therefore indicating that trauma is really the reason for such complication12.

There is again dispute in the literature as to the ideal time of maintenance of calcium hydroxide dressing in the root canal. There are some studies which suggest that calcium hydroxide as an intracanal medicament in cases of intrusive luxations should be kept for 6 weeks– 9 months6.

According to Cvek, calcium hydroxide should be maintained in the root canal for 1– 6 months before obturation with gutta-percha points. A minimum time of 3-4 weeks is recommended for calcium hydroxide dressing following intrusive luxations.

Andreasen et al.18 recommend a splinting period of 6–8 weeks following surgical repositioning, although in the recent studies a shorter period of around two weeks has been shown to permit sufficient reduction in mobility. Numerous investigations have been done to disclose if splinting teeth may aid periodontal and pulpal healing. In an animal experiment, normal masticatory stimulation appeared to eliminate small resorption areas15. In the same manner it has been demonstrated that periodontal ligament recovered 70% of its original strength 14 days following extraction and replantation.16 As clinical healing of the periodontium occurs within 7 days by reattaching to the new junctional epithelium, cases with minor supporting tissue injuries should not be splinted for more than 1 to 2 weeks.17 Ideally, a splint should remain attached to an injured tooth for the shortest time possible, so that, after its removal, the tooth and associated tissues can stay in proper relationship for the healing process to complete itself. Most displaced teeth require around 7 to 14 days for stabilization by splinting18. Hence in this case acid etch composite ligature wire splint was used which is a physiologic method of splinting.

In all cases the tooth should be reviewed within 1 week of the accident to assess the healing process, check the mobility, check and adjust the splint if necessary. Longer periods of splinting can be used depending upon the particular case.

Pulse oximeter is a well established and noninvasive method for measuring vascular health by evaluating oxygen saturation. A vital pulp with an intact vasculature may test non vital if only neurovascular component is injured. This condition is often seen with recently traumatized teeth.19 Though 11,12, 22 gave negative response by thermal testing and electric pulp testing it gave a positive response with pulse oximetry.

Conclusion

Although the recommendations on the treatment of intruded permanent teeth are contradictory,
the current case demonstrates and confirms the possibility that severely intruded incisors may be treated by surgical repositioning, which provides an immediate endodontic access. Although numerous types of splinting methods have been described, the bonded composite resin ligature wire splint stands alone in its simplicity, ease of use, versatility, and reliability. A two year follow up shows satisfactory periapical healing.

References

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2. Andreasen JO. Etiology and pathogenesis of traumatic dental injuries. A clinical study of 1298 cases. Scand J Dent Res 1970;78:329–42.
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13. Sondos Albadri, Halla Zaitoun & Martin Kinirons. UK National Clinical Guidelines in Paediatric Dentistry. Treatment of traumatically intruded permanent incisor teeth in children. International Journal of Paediatric Dentistry 2010;20:1-2.
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15. Andersson L, Lindskog S, Blomlof et al.Effect of masticatory stimulation on dentoalveolar ankylosis after experimental tooth replantation. Endod Dent. Traumatol 1985;1:13–6.
16. Mandel U, Viidik A. Effect of splinting and histological properties of the healing periodontal ligament in the Vervet Monkey (cercopithecus aethiops). Arch Oral Biol 1989;34:209-17.
17. Andreasen JO. The effect of splinting upon periodontal healing after replantation of permanent incisors in monkey. Acta Odontol Scand 1975;33:313-23.
18. Croll, Theodore P. Bonded composite resin/ligature wire splint for stabilization of traumatically displaced teeth. Quintessence Int 1991:22:17-21.
19. E. Calil, C.L. Calderia, G. Gavini and E.M. Lemos. Determination of pulp vitality in vivo with pulse oximeter” International Endodontic Journal. 2008 : 41:741-46.

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