Outcomes of autotransplanted teeth and prognostic factors: a 10-year retrospective study

Efficacy of root canal treatment for autotransplanted third molars: a 6-Year cohort study of 167 teeth in southern China

Background

Autogenous tooth transplantation offers significant advantages and promising success rates for replacing non-retainable teeth. This study aimed to investigate the prognostic factors, especially the impact of root canal treatment (RCT), of autotransplanted teeth in an up-to-6-year follow-up cohort of 167 teeth in Southern China.

Methods

We enrolled adult patients from the Southern Medical University-Shenzhen Stomatology Hospital between 2017 and 2023. Patients underwent autogenous tooth transplantation to replace non-retainable molars with upper or lower third molars with Moorrees tooth development stage ≥5. All surgical procedures were performed by an experienced surgeon. The included patients were followed up for 6~72 (median 28.5) months. Success, failure, and survival rate and prognostic factors were evaluated using univariable Kaplan-Meier, multivariable generalized linear regression, and multivariable COX regression analyses.

Results

The overall success rate is 97.6% with four unsuccessful cases. Herein, two of them were removed, leading to an overall survival rate of 98.8%. A total of 159 cases (95%) received RCT in 3 months. Univariable log-rank analysis showed that RCT (RR 0.109, 95%CI 0.010 to 1.202, P = 0.028) and site relationship between donor and receipt sites (RR 3.359, 95% CI [1.210-9.329], P = 0.020) were two significant prognostic factors of autotransplanted teeth. Multivariable generalized linear regression revealed that RCT is the only significant factor protecting the success rate of autotransplanted teeth (HR 0.003, 95% CI [0.000-0.249], P = 0.010). However, in the Cox regression model, the effects of RCT (HR 0.009, 95% CI [0.000-2.514], P = 0.101) did not reach statistical significance. Other factors did not demonstrate a significant impact in this cohort. These results supported that autogenous tooth transplantation is a viable alternative to conventional implant treatment with strict indications. Our findings underscore the importance of RCT in transplanted teeth with closed or semi-closed apices. Multi-center observational studies with larger sample size and extended follow-up duration may be needed to validate the conclusion.

Autotransplantation of immature second premolar combined with alveolar ridge splitting: A long-term (6-year) follow-up case report

This case report describes a successful autotransplantation procedure for an impacted mandibular left second premolar with incomplete root formation. Despite caries and root resorption, the patient's mandibular left second primary molar was retained. Furthermore, the severe impaction of the mandibular left second premolar ruled out orthodontic realignment. Due to the young age of the patient, dental implantation was not feasible, leading to the selection of autotransplantation as the preferred method for replacing the retained primary molar. To address the insufficient buccolingual width of the recipient site, a combination of piezosurgery-assisted alveolar ridge splitting and guided bone regeneration techniques was employed in this autotransplantation procedure.

Intentional replantation for a Class 4/Stage C cemental tear: Etiology, choice and outcomes of treatment

Cemental tears, root cracks, and associated periapical-periodontal lesions may occur simultaneously in one tooth, and can be effectively managed by intentional replantation and etiological control. A durable splint, along with occlusal and periodontal monitoring, is required as healing progresses slowly and may be insufficient.

Retrospective Follow-up Assessment of Risk Variables Influencing the Outcome of Autologous Tooth Transplantation

INTRODUCTION

This retrospective study aimed to identify which patient-, donor tooth-, recipient site-, and surgical procedure-related variables may influence the outcome of tooth autotransplantation.

METHODS

The sample included 128 autotransplants performed in 122 patients. Single-visit clinical/imaging examinations were used to define the outcome as successful, survival, or failure. The association of potential indicators with the survival or failure categories was analyzed individually and adjusted for confounders through multivariate logistic regression models.

RESULTS

After a follow-up period of 1 to 30.11 years, success was achieved in 71.8% of autotransplants, whereas the survival and failure groups had rates of 14.1% each, and the grouped success/survival rate reached 85.9%. An extraoral time >15 minutes and difficult handling/placement were strong/independent risk covariates for survival and failure categories (odds ratio >1, P < .05). Additionally, unerupted/partially erupted status of the donor tooth was a significant indicator for survival, whereas deficient bone level at the recipient site, surgical extraction, poor initial stability, and lack of prophylactic antibiotics were independently linked to failure (odds ratio > 1, P < .05). The root morphology and socket status acted as modifiers of the effect of the recipient site location on the survival group (P > .05).

CONCLUSION

Based on the results of this study, unerupted/partially erupted status of the donor tooth, surgical extraction, total extraoral time >15 minutes, deficient recipient's bone level, difficult handling/placement of the autotransplant, poor initial stability, and lack of prophylactic antibiotics during the surgical procedure must be considered with caution when performing autotransplantation because of their deleterious influence on the outcome.

An evaluation of 910 premolars transplanted in the anterior region-A retrospective analysis of survival, success, and complications

AIM

The aim this retrospective analysis was to evaluate the survival, success and possible complications of transplanted premolars to the anterior region subdivided in development stage and patient's age.

MATERIALS AND METHODS

The material comprised patients that underwent a tooth transplantation between April 2004 and December 2021. A total of 910 premolars were transplanted in 707 patients. Tooth mobility, oral hygiene, and periodontal parameters were clinically evaluated. Standardized radiographs were used to evaluate pulpal and periodontal healing and root formation. The cumulative survival rate was calculated using the Kaplan-Meier method.

RESULTS

The data were subdivided in three groups based on the stage of root development and patient's age. The average age at surgery was 16 years. The main indication for transplantation was trauma, followed by agenesis and other indications. Two premolars were lost during the whole observation period. The overall survival and success in the immature premolars group after an observation period of 10 years was 99.8%. The 10-year survival and success rate when fully developed premolars were transplanted in the anterior region in adolescents were 100% and 96.3%, respectively. In adults, the 10-year survival and success rate were 87.5%.

CONCLUSION

Transplantation of premolars with developing and fully developed roots to the anterior region in children, adolescents, and adults is a predictable treatment modality.

Eyes wide open to avoid misleading diagnosis and treatment planning

INTRODUCTION

The treatment of impacted and transposed teeth is a challenge for clinical practice. A precise assessment of the relative position of the transposed tooth could lessen the risks of adverse effects, such as root resorption and periodontal problems.

DESCRIPTION OF THE CASE

An 18-year-old patient went to the Orthodontic Department of the Federal University of Juiz de Fora, Brazil for a re-evaluation of the orthodontic treatment to which she had been receiving since the age of 12. Attempted traction of an impacted maxillary canine resulted in root resorption, marked mobility and alteration in the position of adjacent teeth as well as loss of alveolar bone in the anterior region of the maxilla. This tooth was not only partially transposed, but it also had ankylosis, external and internal tooth resorption, which indicated the need for tooth extraction. A change was made to the treatment plan, with the extraction of the canine, bone graft and mesial movement of the posterior teeth.

RESULTS

All the spaces were closed at the end of treatment, with normal overbite and overjet. At the follow-up, the teeth position, the shape of dental arches, disocclusion guides and dental occlusion were preserved. The bone graft in the maxilla showed height and mineral density stability.

CONCLUSION

The presence of the maxillary permanent canines in the dental arch is important for both aesthetics and a functional occlusion. However, despite the importance of their maintenance in the arch, it is well advised that each case be analysed individually.

Validation of a Cox prognostic model for tooth autotransplantation

OBJECTIVES

This study aimed to validate our Cox proportional hazards prognostic model for autotransplantation of teeth with complete root formation using prognostic index (PI) and determine whether the prognosis can be predicted.

PATIENTS AND METHODS

The Protocol group, as a training data set for validation, consisted of 259 autotransplanted teeth to create a PI using the Cox model, as described previously. The Pre-protocol group, as the first validation data set, consisted of 95 autotransplanted teeth treated without a protocol. The Post-protocol group, as the second validation data set, consisted of 61 autotransplanted teeth obtained after the establishment of the prognostic model. Because four prognostic factors, including history of root canal treatment (yes), number of roots (multirooted), source of donor tooth (maxillary tooth), and duration of edentulism (≥2.5 months), were selected as a Cox prognostic model, 16 patterns of PI were constructed. First, the autotransplantated teeth in the Protocol group were divided into low- and high-risk groups respectively according to the median of PI as the cutoff value. The survival curves of low- and high-risk groups were calculated using the Kaplan-Meier method and tested using the log-rank test. Then, in the Pre- and Post-protocol groups, all transplanted teeth were divided into low-and high-risk teeth by the median of PI and the survival curves of low- and high- risk teeth were analyzed statistically in a similar manner.

RESULTS

The survival curves of the low- and high-risk groups diverged significantly in the Protocol and Post-protocol groups. In the Pre-protocol group, the curves of the low- and high-risk groups were separated, and the low-risk survival rate was improved.

CONCLUSIONS

Our Cox prognostic model for autotransplantation of teeth with complete root formation was useful in predicting the prognosis by external validation using PI.

Does Root Development Status Affect the Outcome of Tooth Autotransplantation? A Systematic Review and Meta-Analysis

Background: Tooth autotransplantation is defined as the surgical repositioning of an autogenous tooth in another surgical site within the same individual. Aim: The aim of this research was to analyze the outcome of tooth transplantation using immature donor teeth compared with closed apex teeth and to compare differences between donor tooth positions on the arch. Methods: Electronic and manual literature searches were performed in different databases, including the National Library of Medicine (MEDLINE), EMBASE (OVID), Cochrane Central (CENTRAL), and the digital library of the Universitat Internacional de Catalunya (UIC University) from 1978 to March 2021. Studies were selected when they fulfilled the following criteria: only human prospective clinical studies, minimum sample size of 10 patients, minimum follow-up of 1 year, studies reporting or with at least deducible data on survival rates, immediate tooth autotransplantation with completed or incomplete root formation, and publications in the English language. A meta-analysis of random effects was developed to estimate the global effect measure of the survival rate, success rate, and root resorption involving the total sample, as well as open- and closed-apex groups. Results: Twenty-four articles were eligible for analysis. The Cohen’s kappa corresponding to this review was 0.87, and the risk assessment was considered low–moderate for the included studies. Overall survival and success rates were 95.9% and 89.4%, respectively, with a mean follow-up of 4 years and an overall mean age of 25.2 ± 12.3 years. Closed apex teeth showed a survival rate of 3.9% lower than that of open apex teeth. Higher complication rates were found for both inflammatory external root resorption and replacement root resorption in the closed-apex group, without reaching statistical significance. Conclusions: Tooth autotransplantation is a viable treatment alternative, regardless of the apical condition, with high survival and success rates after a mean follow-up of 4 years. Open-apex donor teeth could be considered the gold-standard option, showing lower complication rates when compared to closed-apex donor teeth. Future randomized controlled clinical studies are needed to examine the long-term prognosis of this technique.

What Are the Complications, Success and Survival Rates for Autotransplanted Teeth? An Overview of Systematic Reviews and Metanalyses

Background: Autotransplantation is the surgical repositioning of a tooth within the same patient. It can be thought of as the controlled avulsion and re-implantation of a tooth and can be a viable alternative to other dental rehabilitation options. This review aimed to evaluate the survival rate (SR), major complications such as ankylosis rate (AR) and infection-related root resorption (RR), and overall success and failure rate (FR) in autotransplanted teeth. Methods: Six databases were accessed up to January 2021 to obtain all systematic reviews and meta-analyses (SRs and MAs). Study selection: After title and abstract reading, data extraction was performed from eligible SRs. The methodological quality was calculated for the included SRs using the risk of bias in systematic reviews (ROBIS) tool. Results: Six SRs were included in this review. The overall failure rate ranged from as low as 2.0% to 10.32%. The 1-year survival was very high (97.4–98.0%). The 5-year survival rate ranged from 81 to 98.2%. Major complications of AR ranged from 1.2 to 6.2%, and RR ranged from 2.1 to 10.4%. Conclusion: The overall findings from these SR and MA are promising; however, all the SRs include only single-arm prospective or retrospective studies, the SRs are of overall low methodological quality, and for the heterogeneity of the included SRs, well-designed comparative studies with a long-term follow-up are recommended.

Autotransplantation of teeth with incomplete root formation: systematic review and meta-analysis

OBJECTIVES

To determine the survival of intentional autotransplantation of developing teeth.

MATERIAL AND METHODS

An electronic search was carried out in the MEDLINE database, Web of Science, and Cochrane Library. The criteria used are the ones described in the PRISMA Declaration. The following MeSH terms were used: ("tooth" [MeSH Terms] OR "tooth" [All Fields]) AND ("transplantation, autologous" [MeSH Terms] OR ("transplantation" [All Fields] AND "autologous" [All Fields]) OR "autologous transplantation" [All Fields] OR "autotransplantation" [All Fields]) AND ("humans" [MeSH Terms]. Randomised clinical trials and prospective and retrospective clinical studies were included.

RESULTS

The meta-analytic study of overall survival included a total of 14 studies, yielding an overall survival rate of 97.9%. In studies with 1-year follow-ups, survival was 98%. The resulting 2-year follow-up rate was 97%, while the 5- and 10-year survival rates were 95.9% and 96.9%, respectively.

CONCLUSIONS

The autotransplantation technique performed in a single-phase and on teeth that have not completed their development is a predictable technique, with a described survival rate at a 2-year follow-up of more than 97%.

CLINICAL RELEVANCE

The technique of dental autotransplantation is considered an important resource for the resolution and rehabilitation of tooth loss in patients, especially in those who are still in a growth period. Moreover, this technique has a low complication rate and a 10-year survival rate of 96.9%. It should therefore be considered a safe and reliable procedure.

Finite element analysis of stress distribution in autotransplanted molars

OBJECTIVE

The biomechanical response of an autotransplanted tooth and surrounding bone to occlusal loads is not well-known. The aim of the present study was to investigate the effect of root form and occlusal morphology on stress distribution in autotransplanted teeth and surrounding bone by using finite element analysis (FEA).

METHODS

Seven FEA models representing different autotransplanted tooth situations were generated: (a) first molar, (b) third molar, (c) root canal-treated third molar, (d) root canal-treated, ankylosed, third molar, (e) crowned third molar, (f) crowned and root canal-treated third molar, (g) root canal-treated, ankylosed, and crowned third molar. Load (200 N) was applied on the occlusal surface, parallel to the long axis of the tooth. Maximum von Mises stress values on dentin and surrounding bone were calculated for each situation.

RESULTS

Differences in stress distribution were observed among models. In ankylosed model, stress was primarily observed at the coronal region of the tooth. The stress was observed more at the coronal region of the tooth in crowned models compared with the non-crowned models. The stress distribution was homogeneous with root canal-treated and crowned autotransplanted tooth.

CONCLUSIONS

The occlusal morphology and root form of the autotransplanted tooth affected the stress in surrounding bone at the transfer site and the biomechanical response of the tooth. The stress was more homogeneous in crowned tooth and primarily observed at the coronal region, which may decrease the risk for root resorption.

CLINICAL SIGNIFICANCE

Root configuration, occlusal form and root canal treatment induce significant changes on the stress distribution on teeth and bone, including characteristic stress concentration and increased stress values. Clinicians can consider crowning autotransplanted teeth for improved stress distribution within the tooth structure.

Tissue Engineering with Compact Bone-Derived Cell Spheroids Enables Bone Formation around Transplanted Tooth

BACKGROUND

Although tooth transplantation is a desirable treatment option for congenital defects of permanent teeth in children, transplantation to a narrow alveolar ridge is not feasible. In this study, we investigated the possibility of bone tissue engineering simultaneously with tooth transplantation to enhance the width of the alveolar bone.

METHODS

Bone marrow mononuclear cells or cortical bone-derived mesenchymal stromal cell spheroids were seeded onto atelocollagen sponge and transplanted with freshly extracted molars from mice of the same strain. New bone formation around the tooth root was evaluated using micro-computed tomography and histological analysis. Tooth alone, or tooth with scaffold but without cells, was also transplanted and served as controls.

RESULTS

Micro-computed tomography showed new bone formation in the furcation area in all four groups. Remarkable bone formation outside the root was also observed in the cortical bone-derived mesenchymal stromal cell group, but was scarce in the other three groups. Histological analysis revealed that the space between the new bone and the root was filled with collagen fibers in all four groups, indicating that the periodontal ligament was maintained.

CONCLUSION

This study demonstrates the potential of simultaneous alveolar bone expansion employing bone tissue engineering approach using cortical bone-derived mesenchymal stromal cell spheroids for tooth transplantation. The use of an orthotopic transplantation model may further clarify the feasibility and functional recovery of the transplanted tooth over a longer period.

Mid-Term outcomes and periodontal prognostic factors Of autotransplanted third molars: A Retrospective Cohort Study

BACKGROUND

Tooth autotransplantation is a valid method for replacing non-restorable teeth. This study aimed to assess mid-term survival and success of autotransplanted third molars and the clinical periodontal parameters and factors predicting successful periodontal attachment apparatus regeneration.

METHODS

In total, 36 patients who had undergone extraction and subsequent autotransplantation of 36 third molars using virtual planning and computer-aided rapid prototyping models by an oral surgeon and endodontist were eligible. Probing pocket depth (PPD), gingival recession (REC), clinical attachment level (CAL), pulpal and periapical healing, root resorption, and radiographic bone loss (RBL) were evaluated. Additionally, a questionnaire evaluated patient-reported outcomes.

RESULTS

The mean age of the participants was 30.2 years with a mean follow-up duration of 29.42 ± 14.56 months. The overall survival and success rates were 97.2% and 91.7%, respectively. No statistically significant differences were found in success and survival rates between open and closed apex groups or between compromised and intact buccal bone groups. No signs of pulp necrosis were found in the open apex group. Progressive replacement resorption was detected in one closed apex case. The mean PPD was 2.7 ± 0.45 mm for all transplanted teeth. REC was 0.13 mm higher in transplanted teeth than in previous hopeless teeth. CAL changes were neither clinically relevant (-0.17 ± 0.66 mm) nor statistically significant. The reported patient satisfaction was high.

CONCLUSIONS

Autotransplantation of third molars is a predictable treatment method, with a 2.5-year cumulative tooth survival and success of 97.2% and 91.7%, respectively, which were not influenced by recipient site integrity or root development.

Autotransplantation of Two Immature Third Molars with the Use of L-PRF

Tooth autotransplantation is a procedure which provides the extraction of an erupted or impacted tooth and its repositioning to another site in the oral cavity. This Case Report describes a successful case of two autotransplantations of open-apex mandibular third molars in place of the hopeless first mandibular molars with the use of L-PRF in a growing patient. A 15-year-old male patient was referred to the Dental Clinic for the extractions of the two hopeless mandibular first molars. Autotransplantation was considered the best treatment option for both sites 36 and 46, because the presence of two impacted mandibular third molars (38 and 48) with an incomplete root formation. Teeth 36 and 46 were extracted and replaced with teeth 38 and 48. The patient had an uneventful healing. At follow-up visits, the two autotransplanted teeth showed physiologic mobility, absence of inflammation and discomfort, and absence of infection; probing depth values were within normal range, and the vitality tests were positive. After 2 years, the teeth in position 36 and 46 showed absence of infection and mobility, and positive pulp vitality tests and the radiographic examinations exhibited closure of the root apices as well as absence of any periapical radiolucency or root resorption. Tooth autotransplantation is a good treatment option in case of tooth loss offering an alternative to traditional or implant-supported prosthesis especially for growing patients.

Effect of Orthodontic Treatment on Tooth Autotransplantation: Systematic Review of Controlled Clinical Trials

This systematic review was focused on evaluating tooth autotransplantation, considering its impacts on the teeth, bone, soft tissues, and aesthetics in orthodontic patients. A bibliographic search was conducted without limitations on year of publication or language in the databases of PubMed, Web of Science, Scopus, Medline Complete, Cochrane, Clinical Trials, and Trials Central. For triage of articles, indications, surgical planning, orthodontic movement, risk factors for treatment, and long-term follow-ups were considered. For outcomes, the results with reference to teeth, alveolar bone, periodontal tissues, and esthetic satisfaction were considered. Risk of bias was evaluated using the methodological index for nonrandomized studies-MINORS. The results showed 10 controlled clinical trials, and no randomized clinical trials were found. The selected studies included 715 patients and 934 autotransplanted teeth among which there were premolars, molars, and anterior teeth evaluated in the long term, indicating that orthodontics associated with autotransplantation indicated a result that was generally clinically acceptable. The quality of the set of evidence was considered medium due to the presence of different methodological problems, risk of bias, and significant heterogeneity in the evaluated studies. There was a sufficient body of evidence that justified autotransplantation in patients who needed orthodontic movement. In teeth, there was an increase in root resorption influenced by orthodontics, but without impacting on the general clinical result in the long term. Bone and periodontal tissue do not appear to be affected by orthodontics. The patient’s aesthetic satisfaction was not considered in the studies.

Effectiveness of a Piezoelectric-Assisted Distraction Osteogenesis Procedure for the Treatment of Ankylosed Permanent Front Teeth

A common complication of tooth replantation after traumatic avulsion is tooth ankylosis causing dental malpositioning, partial loss of function, tipping of adjacent teeth and worsening of aesthetics. The aim of this study is to evaluate the effects of a repositioning procedure of such ankylosed permanent front teeth by a distraction osteogenesis procedure. Five patients (mean age 13.4 years), with an ankylosed permanent front tooth in the anterior area, were enrolled in the present study. After the pre-operatory orthodontic preparation, each selected site was treated with single-tooth dento-alveolar block osteotomy surgery performed with a piezoelectric surgery device with ultrasonic cuts on the buccal side. Subsequently, a custom distraction device, made by a resin splint and a sector expansion screw, was set in such a way it delivered a force with direction and sense towards the planned position of the tooth as well as the osteotomy's incision. After a latency period of 14 days, the distraction of the dento-alveolar block was started with a rate of distraction of 0.8 mm per day. The average shift obtained by the ankylosed teeth was 7.8 ± 0.75 mm (±SD), and the ankylosed tooth was regularly positioned into the occlusion in 20.4 ± 1.85 days (±SD), with a slight relapse (±0.5 mm) observed after 1 year. This study indicates that a therapeutic approach combining piezoelectric surgery and orthodontic therapy may be useful for the treatment of ankylosed permanent teeth in the frontal area with a long-term follow-up over 5 years.