Conservative management of progressive external inflammatory root resorption after traumatic tooth intrusion.

Intrusive luxation is one of the most severe types of dental trauma. The risk of development of inflammatory or replacement root resorption is high if not timely managed. Endodontic intervention is required soon after the occurrence of trauma, in an attempt to prevent or delay inflammatory root resorption. This case report emphasized timely referral for endodontic management of intruded tooth to prevent inflammatory root resorption.

INTRODUCTION

Traumatic tooth intrusion is a type of dental injury that involves displacement of the tooth into the alveolar socket.[1] Because of their locked position in the socket, most of the intruded teeth are not sensitive to percussion and are completely firm. The percussion test often elicits a high-pitched metallic sound, similar to an ankylosed tooth.[1] Radiographically, the tooth is shifted in an apical direction with partial or complete disappearance of the periodontal ligament (PDL) space. Traumatic tooth intrusion usually involves the maxillary anterior teeth and is more common in the primary than the permanent dentition.[2]

Intrusion represents a very complex wound, involving disruption of the marginal gingival seal, alveolar bone, PDL fibers, cementum and the neuro-vascular supply to the pulp.[1] Andreasen found that only 3% of permanent teeth injuries were intrusive luxation and all intruded teeth with closed root apices lost their vitality regardless of the degree of intrusion so endodontic intervention should be done as soon as possible.[1]

Traumatic tooth intrusion might result in unexpectedly severe complications, such as pulp necrosis, inflammatory root resorption, ankylosis, replacement resorption, and loss of marginal bone support. External resorption encountered in 54.8% of the teeth. Pulp necrosis is the most common complication after luxation injuries,[3] and has been reported to occur in almost 100% of fully formed, intruded permanent teeth[1] so, endodontic intervention is required as soon as tooth exposed to oral environment after intrusion to prevent complications.

The management of intruded permanent tooth may consist of (i) allowing spontaneous re-eruption, (ii) surgical repositioning and fixation, (iii) orthodontic repositioning, and (iv) a combination of surgical and orthodontic therapy.[4] Immediate orthodontic force on traumatically intruded teeth would facilitate the dental extrusion, allow an early endodontic access[5] and it can be considered a way to prevent the appearance of ankylosis. This method, although, can increase the risk of external root resorption and marginal bone loss.[6]

This case report describes conservative management of extensive cervical and apical inflammatory root resorption of traumatically intruded tooth developed as a result delayed referral for endodontic management.

CASE REPORT

A healthy 10.5-year-old female patient had history of dental trauma which resulted in complete intrusion of tooth [Figure 1a and b]. Patient initially seen by an orthodontist for forced orthodontic extrusion of intruded tooth. After 6 months of orthodontic treatment intruded tooth repositioned back to its original position [Figure 1c]; and direct composite filling was done to build the broken incisal edge [Figure 1d]. After removal of orthodontic appliance Grade 2 mobility was noticed in tooth 11 and post-treatment radiograph revealed sever external apical and cervical root resorption with large periapical radiolucency around tooth 11 [Figure 2a]; so patient was referred for management of external root resorption.

Figure 1

(a) Complete traumatic intrusion of tooth 11 at the time of trauma. (b) X-Ray ortho pantomogram revealed complete intrusion of tooth 11 after trauma. (c) Orthodontic extrusion of intruded tooth 11 with fixed orthodontic appliance. (d) After completion of fixed orthodontic extrusion and final composite build-up of 11

Figure 2

(a) Radiograph after orthodontic treatment showing external root resorption and periapical radiolucency around tooth 11. (b) X-Ray findings at 3 months follow-up with calcium hydroxide in tooth 11. (c) X-Ray findings at 6 months follow-up with calcium hydroxide in tooth 11. (d) Final obturation radiograph with gutta percha in tooth 11 at 2 year follow-up

Her clinical examination showed mixed dentition with satisfactory oral hygiene. Tooth 11 had Grade 2-3 mobility, was in good occlusion and not tender to palpation or percussion. Tooth 11 responded negatively to pulp sensibility testing (thermal and electrical), while teeth 12, 21, and 22 responded positively. Although, clinical and radiographic findings were alarming for the treatment success and long-term prognosis of tooth 11 but still after discussing plan with parents decided to preserve the tooth 11.

Diagnosis

A pulpless and an infected root canal system with chronic apical periodontitis, apical inflammatory root resorption, and lateral inflammatory root resorption (at the cervical level, on both mesial and distal aspects).

TREATMENT PLAN

Immediate treatment plan was to arrest inflammatory root resorption process by removing necrotic pulp from canal space and placement of calcium hydroxide based intra canal medication.

Definitive treatment plan

Completion of root canal treatment in tooth 11. Regular, long-term clinical and radiographic assessment of traumatized and adjacent teeth on follow-up visit for vitality.

On initial visit root canal treatment started in tooth 11. After pulpectomy working length was determined roughly on periapical radiograph, although the root apex anatomy was distorted because of external apical root resorption. After chemo-mechanical cleaning and shaping with standardized step back filing technique (using master apical file) Calcium hydroxide based intracanal medication was placed and coronal sealing of access opening was done with glass ionomer cements. On follow-up visit after 3 month mobility in tooth 11 was reduced to Grade 1 and periapical radiograph revealed arrested root resorption process and decrease in size of periapical radiolucency [Figure 2b]. Subsequently at 6 months follow-up, tooth mobility reduced to its physiological limit and periapical radiograph revealed arrested root resorption process, disappearance of periapical radiolucency and continued bony defect filling around tooth 11 [Figure 2c]; so obturation completed by using master apical gutta percha points along with accessories (cold lateral condensation technique). Root formation remained continued for teeth 12, 22 [Figure 2c]. Regular follow-ups were made at 12, 18, 24 months. Clinical and radiographic assessment of tooth 11 showed normal healing process with no sign of replacement root resorption or ankylosis [Figure 2d].

DISCUSSION

The treatment for traumatized permanent incisors can pose a challenge. Management of preadolescent with such an injury is determined by two main variables: The stage of tooth development and the amount of intrusion.[7] Studies have shown that, whereas intrusions of less than 3 mm have an excellent prognosis, those with an intrusion of more than 6 mm will ultimately be lost owing to progressive inflammatory resorption following overwhelming injury of PDL cells.[37]

It has been reported that intrusion and avulsion injuries carry a high-risk of inflammatory root resorption, replacement root resorption and dentoalveolar ankylosis due to irreversible damage to the PDL.[8] The follow-up management of dental trauma in which tooth intrusion occurs requires special attention for all structures involved: The pulp, the PDL, and the alveolar bone.[9]

The early complications are mainly loss of pulp vitality and external root resorption so pulp extirpation should be initiated as soon as possible after intrusion with complete root development to prevent inflammatory root resorption. The main late complications that arise when endodontic treatment is not initially performed include loss of vitality and concomitant inflammatory root resorption in teeth with closed apices and obliteration of the pulp tissue in the teeth that remain vital.[10] In this case, sever inflammatory external root resorption of central incisor could be a result of delay in referral for extirpation of necrotic pulp and exaggerated with forced orthodontic extrusion. It has been reported that almost 100% of fully formed, intruded permanent teeth develop pulp necrosis, so pulp extirpation should be initiated as soon as possible after intrusion with complete root development to prevent inflammatory root resorption.[1] Elimination of infected materials from the root canal has been shown to arrest inflammatory resorption with a high degree of success, and the use of calcium hydroxide dressing has been reported to result in a high frequency of periapical healing.[11]

Although, 97% of all inflammatory resorptions are arrested after long-term calcium hydroxide treatment. This has been explained by its antibacterial property and denaturing effect on tissues in the resorption lesion, including resorbing cells, after diffusion through the dentinal tubules.[11] In this case, we found excellent response to arrest the inflammatory process and periapical healing after removal of infected necrotic pulp and use of calcium hydroxide dressing on follow-up visits. It seems that local routes of antibiotic administration are a more effective mode than systemic applications. Various antibiotics have been tested in numerous studies and each has some advantages. They are typically used in conjunction with corticosteroids and these combinations have anti-inflammatory, anti-bacterial and anti-resorptive properties, all of which help to reduce the periapical inflammatory reaction including clastic-cell mediated resorption.[12]

There is no current consensus on optimal treatment for intruded permanent teeth.[5] In 1996, Oulis et al. recommended that each case should be considered individually and the treatment should take into account the severity of the intrusion and tooth mobility.[13]

“Forced orthodontic eruption” has been suggested as a possible treatment option, which might allow for remodeling of bone and the periodontal apparatus. The intruded tooth may be sufficiently repositioned for endodontic treatment within 2-3 weeks, so that inflammatory resorption can be prevented or treated if present.[5] In this case, completely intruded tooth was successfully repositioned with forced orthodontic extrusion but delayed referral for endodonic management developed a severe complications.

CONCLUSION

Traumatic injury to teeth presents a considerable challenge for the practitioner. To cover all these various demands and necessities in a proper and adequate manner, a sound knowledge and experience of many different dental fields is needed and combined surgical, restorative, endodontic, and orthodontic approach are required to achieve an adequate rehabilitation of the patient. It is important that treatment provision is evidence based and holistic to ensure that the best possible dental and personal outcomes are achieved.