Mineral trioxide aggregate pulpotomy in autotransplanted immature mandibular third molar with a 4-year follow-up.

Autotransplantation is the surgical transposition of a tooth from its original site to another, replacing a lost or a compromised tooth by another tooth, usually the third molar in the same individual. This technique is considered a viable method due to its high success rate, well-grounded treatment option, provided the case selection and the procedure followed is within the acceptable limits. Autotransplantation is considered as an alternative approach of oral rehabilitations in a conservative manner mainly in young patients with compromised financial conditions to perform a high cost treatment. It is a fast way to recover function and aesthetic properties without interfering with the orofacial growth. This report describes a successful 4-year follow-up of a case of immediately performed mineral trioxide aggregate (MTA) pulpotomy in autotransplantated mandibular left immature third molar to replace the mandibular left first molar that was extracted due to extensive carious lesion.

INTRODUCTION

Autotransplantation is the surgical transposition of a tooth from its original site to another extraction or surgically formed recipient site in the same individual.[1] Autotransplantation is advocated in various conditions such as teeth with extensive caries, advanced periodontal diseases, congenitally missing, impacted, or ectopically erupting teeth, tooth loss due to trauma, teeth with large endodontic lesions and localized severe periodontitis which does not show promising prognosis.[2] Autotransplantation is cost-effective and shows a higher success rate with the maintenance of a unique sensory system and promoting proper healing of the periodontal environment to sound tissue.[3] It is preferred in young patients as it allows normal orofacial growth.[45] In autotransplantation, misalignment or supraeruption of more than 2 mm of donor tooth can affect the pulp of an otherwise healthy tooth.[6] In such conditions, pulp therapies that can be performed are pulpotomy (partial or complete) or pulpectomy depending upon vitality or maturity of tooth. Pulpotomy is universally accepted treatment in teeth having incompletely formed root involving pulpal exposure. Pulpotomy is the surgical amputation of coronal portion of the pulp to the level of healthy pulp and is followed by the placement of suitable medicament that will promote healing and preserve the vitality of remaining radicular pulp that is necessary for continuous root development.[789] This case report highlights a 4-year follow-up of a case of immediately performed mineral trioxide aggregate (MTA) pulpotomy in autotransplanted mandibular left immature third molar to replace the grossly decayed mandibular left first molar in a 17-year-old female.

CASE REPORT

A 17-year-old healthy Asian girl reported to the department with the chief complaint of pain in the lower left posterior region. Past dental history revealed that the patient had spontaneous pain, followed by swelling in relation to the same tooth around 8 months ago. Clinical and radiographic examinations revealed that the lower left first molar (tooth #36) was irreparably damaged [Figure 1A]. A single implant placement after extraction was one of the treatment options. Considering the patient's age, condition of tooth #36, availability of ipsilateral third molar with incomplete root formation [Figure 1B], economical status, and the patient's willingness, autotransplantation with MTA pulpotomy was decided as a definitive treatment plan. The patient was explained about the risks, complications, and possible outcomes of autotransplantation and MTA pulpotomy. A free and clarified consent form was signed by the patient's mother, where all the risks and complications of the treatment were explained, authorizing the patient's preplanned dental intervention.

Figure 1

An intraoral preoperative radiograph of recipient (tooth #36) (A) and donor tooth (tooth #38) (B). Mandibular left third molar (tooth #38) was extracted carefully (C) and transplanted in the socket of tooth #36. It was in supraocclusion (around 4 to 5 mm) (D)

The standard preoperative procedures were performed: Intraoral antisepsis with 0.12% chlorhexidine digluconate for 1 min and perioral antisepsis with povidone. Under local anesthetic solution with adrenaline (2% lidocaine with 1: 100,000 epinephrine, LOX 2% Neon Lab, India), tooth #36 was extracted. Mandibular left third molar (tooth #38) was extracted using osteotomy, so as to make its extraction easy with minimum trauma to its periodontal tissues [Figure 1C] and was transplanted in the socket of tooth #36. The extraoral time from extraction of the tooth #38 to transplantation was 10 min. After tooth transplantation, it was found that the transplanted tooth was in supraocclusion (around 4-5 mm) [Figure 1D]. Selective occlusal grinding was done to keep the tooth out of any occlusal stresses. This occlusal adjustment resulted in a mechanical exposure of the pulp and, hence, it was decided to perform an immediate MTA pulpotomy. The pulp chamber was enlarged and freshly mixed MTA was packed in the pulp chamber space followed by a glass ionomer restoration [Figure 2A–D]. The tooth was stabilized using 4-0 silk sutures. Nonrigid temporary splinting through malleable orthodontic wire and composite resin from tooth #34 to #37 was executed. The patient was instructed to perform daily mouth rinsing with 0.12% chlorhexidine gluconate, twice a day and was prescribed amoxicillin 500 mg and ibuprofen 400 mg orally for 7 days. The patient was recalled after 1 day to check whether any symptoms were present and the tooth was restored permanently using composite restoration. The patient's mother was instructed regarding the importance of the follow-up appointments and the patient was clinically and radiographically followed up for every 6 months for the next 4 years.

Figure 2

Radiograph of autotransplanted mandibular left third molar (tooth #38) in the socket of tooth #36 (A). Under rubber isolation, one step MTA pulpotomy was carried out (B). Follow-up radiograph at 2 years (C), and 4 years (D) showed complete healing of extraction socket with the appearance of normal lamina dura

DISCUSSION

Autotransplantation is a simple and viable treatment option for missing teeth or for teeth indicated for extraction when a suitable donor tooth is available.[510] Various factors influencing the success of autotransplantation are the patient's age, the stage of root development (open or closed apex), the number of roots present (single or multirooted), oral hygiene, similarity of root morphology of donor tooth with recipient tooth, etc.[1112] It is more successful in young patients because teeth with immature roots show higher success rate due to greater chances of revascularization and adjacent alveolar growth. Chances of regeneration of pulp in autotransplanted immature tooth is very high (around 96%) compared to teeth with closed apices (around 15%). In the presented case, the presence of immature roots was the main reason for such a long-term clinical and radiographic success rate.

Autotransplanted tooth should have intimate contact in buccolingual and mesiodistal direction with the recipient site to improve the level of nutrition and the blood supply for its higher success rate.[1314] In the absence of adequate buccolingual width, the alveolar ridge may get resorbed due to pressure from autotransplanted tooth. In the present case, the buccolingual dimension of the donor tooth was compatible with the width of the recipient socket, but the mesiodistal size of the donor tooth was considerably larger and, hence, the donor tooth was in a supraocclusal position. Autotransplanted tooth #38 showed good initial stability and gingival tissue on the mesial and distal aspects of the tooth were sutured to optimize postoperative healing. In addition, selective occlusal adjustment in tooth #38 was carried out to avoid any occlusal discrepancy. Various treatment options are available for such a clinical situation ranging from enameloplasty to vital pulp therapy including indirect pulp treatment (IPT), direct pulp treatment (DPT), pulpotomy, and pulpectomy depending upon the degree of severity.

Pulpotomy is indicated in permanent, vital teeth with open apices.[15] Here pulpotomy was performed as there was a mechanical exposure due to selective occlusal grinding. Plethora of materials can be used for the pulpotomy. However, nowadays MTA is preferred for pulpotomy purposes.[16] MTA induces predictable and rapid dentin formation with greater structural integrity and completes dentin bridging. It helps in maintaining the integrity of the pulp and apexogenesis. In addition, in response to MTA pulpotomy, the pulp shows less inflammation, hyperemia, and necrosis, as well as a thicker dentinal bridge with more frequent odontoblastic layer formation. Hence, one step MTA pulpotomy was done in the presented case.

CONCLUSION

It can be concluded that autogenous tooth transplantation, when well indicated, planned, and performed, can be a viable alternative mainly in young patients, allowing the reestablishment of the functionality (mastication) and aesthetics as well as to contribute clinically for bone formation stimulus at the transplanted site. Proper planning, surgical technique knowledge, the clinician's ability to perform the procedure, and the patient's compliance have a fundamental role in the success of autotransplantation. The success of autotransplantation can be further influenced by a number of other factors such as the patient's age, the developmental stage of the transplanted tooth, the type of tooth transplanted, the surgical technique employed, and the extra-alveolar time span before the tooth is transplanted. Root resorption and loss of attachment are the major challenges of autogenous tooth transplants.

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Conflicts of interest

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