Survival of a Maxillary Incisor in an Adolescent Female Patient 10 Years After Delayed Replantation

Recreational and sport activities, traffic accidents, and human behavior represent the main causes of trauma in young people. One of the resulting traumatic injuries is avulsion of teeth, which comprises from 0.5% to 3% of injuries in permanent teeth.¹ Other anatomical factors, such as increased overjet with protrusion and inadequate lip coverage, increase the risk of traumatic dental injuries.^2,3

Pulpal and periodontal healing of avulsed teeth normally depends on the stage of tooth development, length of extraoral exposure time, and type of extra-alveolar storage used. A tooth with an open apex has a greater potential for pulpal revascularization and tissue regeneration because it may contain a rich blood supply and stem cells³; pH and osmolarity of the storage medium should be compatible with the survival of periodontal ligament cells.^4-6 Also, knowledge of emergency care at the scene of the dental trauma is critical for the treatment outcome.^1,7

Recall appointments are also crucial for success in cases involving avulsion and other trauma-related injuries. Recall visits allow for an early diagnosis and treatment of complications like pulpal necrosis or root resorption that may occur long after the trauma. If recognized in an early phase, these complications could prove to be treatable, enabling the tooth to remain in place in the oral cavity.

This article presents a 10-year follow-up of a 17-year-old female patient who suffered a facial trauma following an automobile accident and had a replantation of the avulsed tooth several hours later after the tooth had been stored in a dry extraoral condition.

Case Report

At 2:30 a.m. on April 9, 2011, the main author (RM) received a call from his son explaining that he was at the emergency room at a regional medical facility with a 17-year-old female classmate who had fallen on her face onto asphalt while exiting his vehicle and avulsed her maxillary right central incisor (tooth No. 8). The tooth had been recovered, although no attempt was made to remove debris from the root surface. The author spoke with the emergency room physician about replacing the avulsed tooth and possibly performing splinting procedures, which the physician refused to do (for fear of later aspiration).

The author then advised his son to reimplant the tooth himself, explaining the procedure while the son performed and completed the replantation. By this time, the tooth had been out of the oral environment, contained in a dry and contaminated condition, for about 3 hours. The author also instructed his son to bring the young woman to the dental office first thing in the morning.

Early Evaluation

The next morning the patient presented at the author's office for treatment, which was now 7 to 8 hours after the initial incident. The patient was noticeably contused with numerous abrasions throughout her face and lips. Due to readily apparent mobility seen in teeth Nos. 7 through 9, teeth Nos. 6 through 11 were splinted (Figure 1). Tooth No. 8 was repositioned to better align with Nos. 7 and 9. Periapical radiographs showed dislodged teeth Nos. 7 and 8 and possibly Nos. 9 and 10. The patient was advised that endodontic treatment would be needed for teeth Nos. 7 and 8 while Nos. 9 and 10 would be further evaluated at later recall visits. Additionally, clindamycin had been prescribed at the emergency room. During this initial dental office visit, the author also prescribed a Medrol Dosepak (methylprednisolone) to aid with swelling and inflammation. The patient was advised to return to the clinic in 7 to 10 days for evaluation and endodontic treatment.

Ten days later, the maxillary anterior teeth were re-evaluated, both visually and radiographically. No additional pathology was noted with tooth No. 8; however, the periapex of tooth No. 7 was widened, and mobility of tooth No. 6 with sensitivity to percussion was noted. The patient was told that tooth No. 6 would now require endodontic treatment also, but it may not need a crown as the clinical crowns on teeth Nos. 6 through 8 were intact, although several fracture lines/crazes were visible in these teeth. Also, composite repair would be required on tooth No. 7, as well as placement of fiber posts in teeth Nos. 6 through 8 due to the resulting loss of tooth structure once restorative treatment was ultimately begun and fracture lines were removed. The patient had discontinued her antibiotics on her own in the previous couple of days, and her facial abrasions were now healed.

Endodontic Treatment

Two weeks after the initial incident, the patient returned to the author's office for endodontic treatment on teeth Nos. 7 and 8 (Figure 2). After debridement, 10% sodium hypochlorite irrigation, and calcium hydroxide placement, the access cavities were closed with a eugenol-free temporary filling material (Coltosol^® F, Coltene, products.coltene.com). At this visit, severe gingivitis with granulation tissue growth was noted both palatally and facially from canine to canine. Internally, tooth No. 8 evidenced no suppuration. However, clindamycin 150 mg was prescribed because bone dissolution was rapidly progressing radiographically and the patient would benefit from completing her antibiotic regimen that was originally prescribed.

One week later, the right central and lateral incisors were re-evaluated radiographically, and both were accessed and subsequently rinsed and medicated with Mycitracin^® (neomycin-bacitracin-polymyxin cream). After a phone consultation with a local endodontist, it was recommended that diflucan 150 mg be added to the medications, along with the clindamycin, due to the increasing bone resorption evident radiographically adjacent to No. 7 as well as the difficulty that was encountered on resolving this rapid bone loss.

On May 12, 2011, the author initiated endodontic treatment on teeth Nos. 6 and 7. Each tooth was opened and irrigated with sodium hypochlorite. Mycitracin was placed within each, and both were closed.

Nine days later, on May 21, tooth No. 8 was again irrigated and medicated with Mycitracin and sealed. The bonded wire splint that had been placed at the first appointment after the accident was also removed. The granulomatous tissue on the lingual aspect of tooth No. 8 had resolved. The periapical radiograph showed mild interproximal bone loss on tooth No. 7.

On May 25, 2011, teeth Nos. 6 through 8 were obturated with gutta-percha and sealed with eugenol-free root canal sealant (Sealapex^™, Kerr, kerrdental.com). Final periapical radiographs were obtained; teeth Nos. 6 through 10 were polished to remove remaining bonding material. One week later, fiber posts (ParaPost^®, Coltene) were placed in teeth Nos. 6 through 8, and composite (Herculite^™, Kerr) was used to seal the lingual access of these three teeth.

Follow-up Care and Further Endodontic Therapy

The patient was seen for follow-up at 3 months and again at 13 months after the accident. At the 13-month visit, examination of the teeth showed no signs or symptoms of endodontic failure, radiographically or intraorally. The periodontal ligament space had returned to normal width, and interradicular bone density had returned. Additionally, at periodic 6-month recall visits over the subsequent 3 years, no further changes were noted. At each visit the patient presented in good spirits with a pleasing smile and with continued good oral hygiene, which was much improved compared to when she first presented following the accident. Figure 3 shows a radiograph at 2 years post-treatment.

In August 2015, however, the patient presented for an emergency visit, where she reported falling on her face carrying logs in her front yard. Periapical radiographs showed no fractures and no periapical pathology. The patient was advised to eat only a "gentle" diet and be re-evaluated as needed.

One month later, a periapical radiograph was taken to re-evaluate tooth No. 9 where a periapical lesion was noted. The patient was advised at this point that endodontic treatment was required and was subsequently initiated on tooth No. 9. Additionally, in early December 2015, a fiber post was placed in tooth No. 9 because of concerns over future fracture/chipping of the clinical crown.

Over the next year and a half, recall visits showed no signs or symptoms of further pathology. Conversely, at a hygiene recall appointment in April 2018, tooth No. 8 showed signs of root resorption on the periapical radiograph, although the resorption did not progress over the following 26 months, as noted at recall visits. Figure 4 shows a radiograph at 8 years after the accident.

The patient was last seen on January 26, 2021, 10 years after the initial accident. At that time she had no further signs of root resorption beyond that which was noted earlier.

Discussion

In contemporary dentistry, treatment modalities aimed at retaining teeth deemed to have an unfavorable prognosis are often bypassed in favor of implant placement instead. While implantology has revolutionized dentistry, implants do not have inherent, automatic success. When an implant is placed and restored successfully, these restorations have their own expected lifespan. When a tooth has been avulsed traumatically, replantation should be an initial consideration rather than an assumption of an implant treatment plan. Although an implant may ultimately prove to be the best course of action in many circumstances, general practitioners should have the knowledge and clinical repertoire to complete a reimplantation procedure if the situation warrants such treatment. Maintaining a patient's dentition should remain sacrosanct in dentistry. Indeed, intentional replantation following extraction may be the optimal course of action to maintain the dentition in some cases. An example of this is in the repairing of faulty endodontic treatment or the removal of other dental pathology.⁸ These cases, of course, are done under controlled conditions in a clinical setting.

Another factor is that traumatic tooth avulsion usually occurs outside the clinical setting. To improve the prognosis of avulsed teeth in these situations, it is paramount that immediate replantation be attempted at the time of the injury. Immediate replantation is the optimal practice for avulsed permanent teeth, but if this is not feasible, the tooth or teeth must be stored in the mouth of the patient inside the lip or cheek or in a container with saliva or milk for as short a period as possible, preferably no longer than 30 minutes.⁹ Also, a solution such as Hank's Balanced Solution, if available, should be used in transporting an avulsed tooth to the dental clinic. There should be minimal manipulation of the root surface of the tooth.

Dry storage conditions may drastically reduce the favorable prognosis.¹ In the present case, however, the dry storage did not seem to affect the performance of the replantation. This could be due to the timely visit to the dental office and the endodontic treatment performed relatively soon after the avulsion, combined with active hygiene recall.

Replanted avulsed teeth usually show signs of complications, such as inflammatory and replacement resorption due to dry storage and/or delayed replantation.² The results of this case report demonstrate that even after an extended extraoral period, avulsed teeth may be replanted followed by endodontic treatment. If the procedure is done properly, the patient might be able to maintain the tooth for several years, despite the potential for a negative outcome. Despite these adverse possibilities, the continued use of the tooth will delay the need for implant or other prosthesis placement and maintain space in the dental arch. This could prove invaluable for younger patients who have not completed their growth cycles.

Normally, in cases with extraoral exposure time longer than 60 minutes, external root resorption occurs, with the entire root being replaced with bone (replacement resorption).⁴ Complete root resorption typically occurs within 3 to 7 years in patients aged 8 to 16 years old.¹ In this case this only began to happen at the 8- to 10-year follow-up.

In the present case report, tooth No. 8 was still retained after 10 years even though it had a long-term extraoral dry storage at the time of avulsion and showed only a "minimal" infraocclusion, according to Malmgren and Malmgren's classification (Index 1: <1/8 of the crown height, compared to the homologous maxillary incisor with relatively healthy periodontal ligaments).¹⁰ This minimal infraocclusion was to be expected, as the avulsion occurred after the pubertal growth spurt.

Finally, a shorter flexible splinting time than the 6 weeks used in the present case may be preferred, according to the guidelines of the International Association of Dental Traumatology, which were published shortly after the patient's initial visit, although a longer period does not seem to affect successful periodontal healing after replantation.^11,12 This case report agrees with a recent study and other articles showing that endodontically treated traumatized teeth can be kept functional.^13-15

It should be noted that the high risk and potential costs of reimplanting an avulsed tooth must be conveyed to the patient. When considering the cost of the root canal and post, the numerous follow-up visits, and the very real possibility of reimplantation failure, the potentially high costs/fees need to be addressed with the patient. The predictability of dental implant placement may outweigh the reimplantation of the tooth, and this should be part of the clinician-patient conversation.

Conclusion

This case report underscores the importance of timely and appropriate intervention in the management of avulsed permanent teeth, even in emergency situations. Despite the extended extraoral dry storage, minimal amount of root surface cleaning, and delayed replantation, the long-term retention of the adolescent patient's maxillary central incisor over a 10-year period is a compelling example of how maintaining the natural dentition remains a viable and sometimes preferable treatment option. While dental implants offer excellent outcomes in many cases, they should not automatically be used to replace efforts to preserve a patient's natural teeth-particularly in younger individuals. With diligent follow-up, proper endodontic care, and patient compliance, even teeth with guarded prognoses may achieve functional and esthetic success for years.

About the Authors

Robert E. McCalla, DDS
Assistant Professor, Department of General Dentistry, University of Tennessee Health Science Center, Memphis, Tennessee

Clint Conner, DDS
Assistant Professor, Department of General Dentistry, University of Tennessee Health Science Center, Memphis, Tennessee

Jeffrey Kalmowicz, DDS
Associate Professor, Department of General Dentistry, University of Tennessee Health Science Center, Memphis, Tennessee

Franklin Garcia-Godoy, DDS, MS, PhD, PhD
Professor, Department of Bioscience Research, University of Tennessee Health Science Center, Memphis, Tennessee

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