Survival and success rates of autotransplanted premolars: A prospective study of the protocol for developing teeth

Digital Simulation and Designing of a Novel Osteotomy Guide for Autotransplantation in the Anterior Region

Autotransplantation of teeth (ATT) is a viable treatment option for replacing teeth lost due to various reasons. Periodontal ligament (PDL) on the donor tooth is one of the most crucial factors determining the success of ATT. To preserve the PDL during surgery and improve the success rate of ATT, digital dentistry has been applied to ATT. In this article, a digital workflow including surgical simulation, a three-dimensional (3D) replica fabrication, and a novel osteotomy guide design is introduced. Digital simulation of ATT on a patient's integrated model enables visualization of anatomical structures and the 3D position of the donor tooth prior to the actual surgery. The 3D-printed osteotomy guide allows the transfer of the direction and depth of the planned osteotomy into the intraoral environment. The 3D replica helps prepare the recipient site before the actual transplantation, which minimizes the extra-alveolar time of the donor tooth and decreases trauma during the try-in process. The proposed virtual planning and the use of the guide and the 3D replica can facilitate the surgical procedures while minimizing complications.

Prognostic factors for autotransplanted third molars with completely formed roots: A retrospective cohort study

BACKGROUND

The autotransplant of third molars to replace missing teeth is gaining attention. This study aimed to analyze factors influencing the success, survival, and inflammatory root resorption (IRR) of autotransplanted third molars with completely formed roots.

METHODS

A total of 160 patients who underwent autotransplant of third molars with completely formed roots were evaluated retrospectively, involving 168 teeth. Preoperative, intraoperative, and postoperative variables were assessed to identify prognostic factors for success, survival, and IRR.

RESULTS

The average (SD) follow-up was 5.21 (1.99) years. The success, survival, and IRR rates were 75.0%, 91.1%, and 17.3%, respectively. Cox proportional hazards regression analysis revealed that both apical resection and retrofilling (ARR) (P < .001) and donor tooth replicas (P < .001 for success and IRR; P = .013 for survival) were associated significantly with success, survival, and IRR. Furthermore, root canal treatment timing and patient age significantly affected success and survival, respectively (P = .006 and P = .036). The use of donor tooth replicas significantly reduced both the surgical time (P < .001) and extraoral time of the donor tooth (P < .001), whereas ARR increased the extraoral time of the donor tooth (P = .002). The use of a single root donor tooth was associated with a reduced surgical time (P = .003).

CONCLUSIONS

Using donor tooth replicas and avoiding ARR contributed to increased success and survival rates and prevented IRR.

PRACTICAL IMPLICATIONS

Third molars with completely formed roots are suitable donors for replacing missing teeth, provided that appropriate preoperative, intraoperative, and postoperative indications are considered.

The Effects of Different Developmental Stages on Bone Regeneration of Periodontal Ligament Stem Cells and Periodontal Ligament Cell Sheets In Vitro and Vivo

Periodontal ligament stem cells (PDLSCs) have broad applications in tissue engineering and regeneration. However, the function of PDLSCs changes in different microenvironments. This study aimed to explore the effects of different developmental stages on the biological characteristics of PDLSCs. Here, PDLSCs were successfully cultured from the periodontal tissues of various groups, including a group with immature roots, a young group with mature roots, and an aging group with mature roots. By comparing the results of the three experimental groups, we found that the donors with immature roots exhibited the best proliferative ability and osteogenic differentiation, whereas the aging group demonstrated the worst proliferation. The trend for adipogenic differentiation was the opposite to that for osteogenic differentiation. The cell sheet and in vivo experiments revealed that in the immature root group, the cells produced more extracellular matrix and new bone and better absorbed the implant materials. These results indicate that PDLSCs perform various functions at different stages of development. In clinical applications of PDLSCs for periodontal regeneration, donors with incompletely developed roots have stronger biological characteristics.

Long-term survival of 57 premolars consecutively transplanted to premolar sites

INTRODUCTION

The objective of this study was to report the long-term outcome of autotransplantation of premolars to other premolar recipient sites.

METHODS

The sample was limited to adolescents seeking orthodontic treatment, and all had 1 or 2 premolars transplanted to a recipient site in which a premolar was congenitally missing. The transplantations were performed between 1980 and 2008, comprising 29 premolars in 22 males and 28 premolars in 22 females. Systematic clinical and radiographic follow-up varied from 1 year to 36.8 years, with a mean observation time of 18.9 years and a median of 19.2 years. Of the 57 transplanted teeth, 52 were subjected to orthodontic forces.

RESULTS

A total of 9 of 57 teeth (15.8%) were lost during the observation period, and 8 of 9 lost teeth had been functional for at least 9 years posttransplantation. Of the 48 surviving transplants, 6 did not meet the criteria for success, giving an overall success rate of 73.7%. Complications were diagnosed within 5 years from the transplantation in 4 of 57 teeth (7.0%) and later in 11 of 57 (19.3%). The Kaplan-Meier survival curve shows that the complication-free proportion of transplants decreased at a constant rate over the observation time. The average survival time, taking censoring into account during follow-up of 36.8 years, was estimated as 28.5 years. The complications in the 15 teeth were classified into 4 categories: periapical lesions (6 teeth), inflammatory resorption (5 teeth), abrupt fracture (2 teeth), and ankylosis (2 teeth).

CONCLUSIONS

Overall, premolar transplants in all stages of root formation have high success and survival rates. Transplants with complications may survive temporarily and preserve critical arch space and alveolar bone. Transplants with normal healing may have latent weaknesses that can eventually affect long-term survival.

Translational approach to tooth autotransplantation: A 27-year case study

BACKGROUND

The aim of this case report was to present a translational approach to tooth autotransplantation using jiggling forces to enlarge the periodontal ligament (PDL) space before autotransplantation, with the goal of improving treatment success and long-term survival.

METHODS

A 23-year-old patient, undergoing orthodontic therapy and with an unrestorable maxillary first molar, was proposed to have a healthy and fully-erupted maxillary third molar transplanted in the socket of the first molar. Jiggling forces were applied to the third molar to enlarge the PDL space and facilitate the preservation of PDL fibers on the root surfaces during the extraction.

RESULTS

Jiggling forces induced hypermobility and widened PDL space of the third molar. The autotransplantation was successful and the patient was followed regularly over a 27-year period. At the 27-year visit, the patient showed optimal chewing function, oral plaque control, and absence of gingivitis. The transplanted molar exhibited periodontal health and absence of mobility. Probing depth of 5 mm and radiographic external root resorption was noted on a localized area of the transplanted tooth which had experienced traumatic and unintentional removal of PDL fibers during the extraction.

CONCLUSIONS

A translational approach was proposed by integrating knowledge from the fields of orthodontics, trauma from occlusion, and replantation. It validated the crucial importance of maintaining healthy PDL fibers on the root surface and demonstrated clinically the successful autotransplantation of a fully formed third molar into the socket of a first molar with a retention of 27 years.

KEY POINTS

Why is this case new information? This case provided evidence of successful autotransplantation of a molar with complete root formation. It reported the longest-term follow-up (27 years) present in the literature. Most importantly, it used a translational medicine approach to apply concepts from the fields of orthodontics and traumatic occlusion to improve the success of the autotransplantation procedure. What are the keys to the successful management of this case? Jiggling forces induced tooth hypermobility and increased the PDL space of the tooth planned for autotransplantation. In turn, they facilitated the atraumatic extraction and preservation of the PDL fibers on the transplanted tooth, improving the success of the reattachment of periodontal fibers. What are the primary limitations to success in this case? Traumatic extraction resulting in the unintended removal of PDL fibers from the tooth planned for autotransplantation, or intentional removal of PDL fibers with root planing are expected to decrease the success rate of the autotransplantation procedure. This is due to the lack of viable PDL cells necessary for reattachment.

Advancements in tooth autotransplantation

BACKGROUND

Tooth autotransplantation (AT) involves the surgical relocation of a tooth from 1 site in the mouth to another site within the same patient. This approach is a good option in a growing patient when dental implant placements or fixed bridges are not suitable and when preserving natural teeth is a priority. Tooth AT is a complex procedure that requires specialized skills from a multidisciplinary team with careful patient and tooth selection and treatment planning.

TYPES OF STUDIES REVIEWED

The authors provided a review of the state of knowledge and research on tooth AT and presented a case scenario and barriers to adoption, with a focus on the United States.

RESULTS

Success rates for tooth AT can vary depending on several factors, including the patient's overall health, specific tooth involved, skill of the dental surgeon, and postoperative care provided. Long-term outcomes of autotransplanted teeth have been cited in the literature with impressive longitudinal follow-up spanning up to 26 years. Results of several systematic reviews showed survival rates from 75% through 98%.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Adoption of tooth AT has grown over the years, owing to advancements in dental techniques, improved patient outcomes, and increased awareness among both dentists and patients. Increasing awareness and availability of tooth AT to replace missing teeth can provide a natural and functional alternative to traditional prosthetic options. Tooth AT helps preserve the alveolar bone in growing patients and can offer excellent esthetic and functional outcomes.

Computer-aided design and computer-aided manufacturing poly (methyl methacrylate) interim veneers for immediate esthetic restoration of autotransplanted teeth

Autotransplanted teeth in the maxillary anterior region should be restored or reshaped as soon as possible for functional and esthetic reasons as well as the well-being of the patient. However, such tooth restorations are frequently not carried out immediately after tooth transplantation because the process could have a negative impact on the healing process. The development of a simple, immediate, and atraumatic esthetic interim restoration would be of great benefit to both the clinician and patient and address all the concerns caused by immediately preparing the tooth postoperatively and cementing a permanent restoration. This report describes the use of CAD-CAM technology to create poly (methyl methacrylate) veneers preoperatively that can be cemented extraorally on the extracted donor tooth for the immediate and interim recontouring of autotransplanted anterior teeth.

Use of 3D printing models for donor tooth extraction in autotransplantation cases

OBJECTIVE

To clarify whether the 3D printing model has auxiliary functions in toto extraction of donor tooth in autotransplantation cases.

METHODS

Two hundred and sixty patients who would have operation of ATT were divided into two groups. In group 1, determination of the tooth extraction in toto was predicted only according to the clinical and imaging examination. In group 2, the prediction was performed according to the clinical and imaging examination as well as the 3D model of donor tooth pre-extraction. A prespctive clinical study was designed on intra-group comparison between the predicted and actual donor teeth situation when extraction in cases of ATT. The consistent rate for the predicted results and the actual results were compared with the two groups.

RESULTS

A remarkable difference was observed between the predicted results and the actual results of tooth positions and root numbers in group without model (p < 0,05). The consistency rate of the model group (94.62%) was significantly higher than that of non 3D model group (86.15%) (p = 0.034).

CONCLUSION

The 3D printing model for the donor tooth is helpful for dentists to predict the accuracy of toto extraction of donor teeth in autotransplantation cases.

Successful Non-Surgical Root Canal Treatment on Auto-Transplanted Maxillary Premolar with Apical Periodontitis

Auto-transplantation is a procedure that replaces traumatized or congenitally missing teeth. While most auto-transplanted teeth are successfully integrated into recipient sites, the donor tooth may develop apical periodontitis, causing early failure. In the present case report, the periodontic resident performed the procedure on a 15-year-old male by selecting donor teeth #4 and #13 and transplanting them at recipient sites #29 and #20, respectively. After 6 weeks, the patient was referred to the endodontic resident for evaluation of tooth #20 due to symptom development. While one auto-transplanted tooth (donor tooth #4, recipient site #29) was successfully integrated, the other (donor tooth #13, recipient site #20) was unsuccessful: the patient was diagnosed with pulp necrosis and a chronic apical abscess. Because of the patient's age, collaboration among periodontic, endodontic, and orthodontic residents/specialists informed the clinical decision to pursue non-surgical root canal treatment (NSRCT) rather than extraction. The canal was cleaned and shaped to a size #80 using copious irrigation of 2.5% sodium hypochlorite (NaOCl), followed by 17% ethylenediaminetetraacetic acid (EDTA) via the EndoVac Negative Pressure Irrigation system. The tooth was dried with paper points, and then calcium hydroxide was mixed with 2.5% NaOCl and placed with an amalgam carrier 2 mm from the radiographic apex. The tooth was next temporized with Teflon tape and Fuji TRIAGE. Four weeks later, after confirming the patient was asymptomatic and tooth mobility had decreased, the canal was obturated using EndoSequence Bioceramic Root Repair Material Fast Set Putty in 2 mm incremental layers to achieve a three-dimensional fill and create an apical plug to prevent gutta-percha extrusion, then backfilled in incremental layers of gutta-percha to the cementoenamel junction (CEJ). At the 8-month follow-up, the patient was asymptomatic, and the periodontal ligament (PDL) had no signs of periapical pathology. When teeth undergoing auto-transplantation procedures develop apical periodontitis, NSRCT can be implemented.

Availability of Third Molars as Donor Teeth for Autotransplantation to Replace Congenitally Absent Second Premolars in Children and Young Adults

The aim of the study was to assess the presence and distribution of third molars (M3) regarding their autotransplantation in patients with congenital absence of second premolars (PM2). Additionally, M3 development in relation to patients' age and gender was investigated. Panoramic radiographs of non-syndromic patients with at least one congenitally absent PM2 were used to assess the localization and number of missing PM2 and the presence or absence of M3 (minimum age 10 years). The alternate logistic regression model was applied to analyze associations between the presence of PM2 and M3. A total of 131 patients with PM2 agenesis were identified (82 females, 49 males). At least one M3 was present in 75.6% and all M3 were present in 42.7% of patients. A statistically significant association between the number of PM2 and M3 agenesis was found; the effects of age and gender were not significant. More than half of M3 in patients between 14-17 years old had completed ¼ of their root development. The congenital absence of maxillary PM2 was associated with the absence of maxillary PM2, M3, and no correlation was found in the mandible. In patients with PM2 agenesis, at least one M3 is often present and can be considered as a donor tooth for autotransplantation.

The outcomes of auto-transplanted premolars in the anterior maxilla following traumatic dental injuries

BACKGROUND/AIMS

Tooth auto-transplantation is a treatment option, which is often not considered to replace anterior maxillary incisors in children and adolescents. There are multiple prognostic factors that may influence the outcomes of premolar auto-transplantation, but there is limited evidence from human studies. The aim of this study was to report the outcomes of auto-transplanted premolars in the anterior maxilla following traumatic dental injuries (TDIs) and to identify their prognostic factors.

MATERIALS AND METHODS

The clinical records of patients who had premolars transplanted in the anterior maxilla following TDI, with appropriate radiographs and a minimal of 1-year follow-up, were reviewed retrospectively. A specific data extraction form was developed, tested and used to collect information for the prognostic factors and outcomes.

RESULTS

The cohort included 120 patients with 144 auto-transplanted premolars. The mean age was 12.2 years (±2.0), and the mean observation period was 3.7 years (±1.8). The success rate was 80%, and the survival rate was 93%. Unfavourable outcomes included external replacement resorption in 12.5%, uncontrolled external inflammatory resorption in 2.7%, and both resorption types in 4.9% of teeth. Periodontal healing was significantly associated with donor tooth root maturity, graft handling at the time of surgery including ease of donor tooth extraction and placement at the recipient sites, recipient site alveolar bone status, and post-operative transplant mobility. Seventy-four teeth (53.4%) were immature at the time of transplantation where pulp revascularisation was anticipated, and 52 (70%) of those had radiographic and clinical signs of pulp healing. Pulp healing was significantly related to donor tooth eruption stage, ease of extraction of donor tooth, and ease of placement in the recipient site.

CONCLUSIONS

Good outcomes were observed for premolar teeth auto-transplanted in the anterior maxilla. The main prognostic factors were ease of extraction of donor tooth and ease of placement in the recipient sites and donor tooth root maturity.

Tooth Autotransplantation as an Alternative Biological Treatment: A Literature Review

Tooth autotransplantation is the treatment modality in which a tooth is transferred from one site to another in the same person. This technique has a history of centuries. However, it is not well-known or well-documented. Essential aspects of the clinical procedure, criteria for performing tooth autotransplantation, advantages, disadvantages, and complications are also discussed in the review. It has been a public health concern considering the prevalence of dental trauma in children, the financial burden of treatment, and the long recovery times associated with dental injuries. There is evidence that tooth autotransplantation is an effective method of restoring missing teeth, particularly for growing children. Even if autotransplantation fails, the soft tissue and bone conditions would likely still be suitable for subsequent implant treatment. Appropriate patient and tooth selection are essential to the technique's success. Other prognostic factors are also discussed. The findings from the available literature suggest that tooth autotransplantation is a viable and cost-effective technique. This paper discusses the literature and protocols the authors implemented for autotransplantation of the tooth.

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.

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.

Status of the alveolar bone after autotransplantation of developing premolars to the anterior maxilla assessed by CBCT measurements

Background/Aims

Autotransplantation of developing premolars is an established treatment to replace missing teeth in the anterior maxilla in growing patients with a reported success rate of over 90%. The normal shape of the alveolus is observed after transplantation, but data on the presence and amount of alveolar bone after healing has not been previously reported. The aim of this study was to look for potential differences in alveolar bone dimensions between sites where autotransplanted premolars replaced missing incisors and control sites of contralateral incisors.

Material/Methods

There were 11 patients aged between 10 and 12 years five months (mean age: 10 years and 7 months) who underwent autotransplantation of a premolar to replace a central incisor. Cone Beam Computed Tomography (CBCT) performed at least 1 year after transplantation served to evaluate bone at sites of autotransplanted premolars and controls (contralateral maxillary central incisor). The thickness of the labial bone, plus the height and width of the alveolar process were measured on scans and compared at transplant and control sites.

Results

Mean thicknesses of the labial bone at the transplant and control sites were 0.78 mm and 0.82 mm respectively. Mean alveolar bone height was 15.15 mm at the transplant sites and 15.12 mm at the control sites. The mean marginal thickness of the alveolus was 7.75 mm at the transplant sites and 7.98 mm at the control sites. Mean thicknesses of the alveolus for half of its vertical dimension at the transplant and control sites were 7.54 mm and 8.03 mm, respectively.

Conclusion

The mean values of bone thickness, width and height of the alveolar process at sites of transplanted premolars were comparable to the mean values for the control incisors. Successful autotransplantation of developing premolars to replace missing central incisors allowed preservation of alveolar bone in the anterior maxilla.

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.

A retrospective analysis of autotransplanted teeth including an evaluation of a novel surgical technique

OBJECTIVES

To assess survival rates and frequency of complications for immature and mature autotransplanted teeth after at least 1 year in function.

MATERIALS AND METHODS

All consecutive patients who had undergone tooth autotransplantation between 2000 and 2018 were invited to a clinical and radiographic follow-up examination. First, survival rates were calculated on the basis of a phone inquiry. A clinical follow-up examination allowed for the calculation of the success rate, i.e., absence of any potentially adverse clinical and radiographic findings of the autotransplanted teeth. Moreover, the effect of demographic, dental, and surgical variables on survival/success was analyzed statistically.

RESULTS

Thirty-eight teeth in 35 patients were transplanted during the study period. Three teeth in 3 patients were excluded due to missing records. All other patients were successfully contacted and interviewed by phone. Out of these 35 transplants, 32 were still in function, and 3 had been extracted, yielding a 91.4% survival probability after a median follow-up of 3.4 years. Of the 32 teeth qualifying for the success analysis, 20 (62.5%) showed absence of potentially adverse findings, while 3 (9.4%) required root canal treatment (RCT). Out of the 9 mature, root-end resected transplants, 4 exhibited ongoing pulp canal obliteration, all with a single root canal. Postoperative and potentially adverse findings or failures were found more frequently in the group of mature transplants (55.6%) than immature transplants (30.4%) and for molars (72.7%) than premolars (17.6%) or canines (25%). None of the potential predictors had a statistically significant effect on survival or success.

CONCLUSION

Autotransplanted teeth yielded a satisfying midterm survival rate regardless of their stage of development. An additional, extraoral root-end resection of mature transplants may lead to rates of revascularization and postoperative pulp canal obliteration higher than the data reported on unmodified mature transplants.

CLINICAL RELEVANCE

Extraoral root-end resection of mature teeth shows promising outcomes for transplants especially with a single root canal and uncomplicated root morphology.

Autotransplanted premolars with incomplete root formation in a growing patient with multiple missing teeth

A boy aged 8 years 11-months with 4 missing teeth in his mandibular arch and with a skeletal Class II pattern was treated with autotransplantation of developing premolars from his maxillary arch with the aid of temporary skeletal anchorage devices. The active treatment duration was 25 months. After treatment, he had a normal occlusion, and his profile was improved. Posttreatment records at 12 months showed stable occlusion and successfully autotransplanted premolars.

Posterior tooth autotransplantation: a case series

Tooth autotransplantation is the technique of transplanting embedded, impacted or erupted teeth from one site into another in the same individual. Autotransplantation can provide a long-term, cost-effective and biological solution for adolescent patients with congenitally missing teeth or significantly compromised teeth when a suitable donor tooth is available. Successful autotransplantation of immature teeth can offer many advantages for a growing patient, including a normally functioning periodontium, proprioception and preservation of alveolar bone volume. Even in the event that an autotransplanted tooth does eventually fail, the bone and soft tissue conditions are likely to be conducive for subsequent implant treatment. Despite the significant physiological and cost-benefit advantages, tooth autotransplantation remains relatively underutilized, as the procedure is considered to be technique-sensitive. Although carefully considered individual case selection and surgical skill are the critical determinants for success, advances in three-dimensional computed tomography and rapid prototyping have the potential to simultaneously reduce the technique sensitivity and increase the predictability of the autotransplantation procedure. It is hoped that this case series will provide greater awareness and an appreciation of the tremendous value of autotransplantation for the management of patients with congenitally missing or significantly compromised posterior teeth.

Technology at the service of surgery in a new technique of autotransplantation by guided surgery: a case report

Background

The aim of this case report was to use a surgical technique for autotransplantation of tooth using virtually planned 3D printed surgical templates for guided osteotomy preparation of the recipient of donor tooth.

Case presentation

An 18-year-old male patient received autotransplantation of the right mandibular third molar to replace an included right second molar. This procedure was based on guided implant surgery methods by superimposition of DICOM files and 3D data sets of the jaws. In order to design a 3D-printed template with the aid of a fully digital workflow; the third molar was conserved in PRGF during the surgical procedure and the tooth socket was prepared with a template and the help of a 3D-printed donor tooth copy in order to prevent iatrogenic damage to the donor tooth. This template and replica were manufactured using 3D-printing techniques. The transplanted tooth was placed in infra-occlusion and fixed with a suture splint and root canal therapy was performed 15 days later. The intervention was be accomplished by performing preplanned virtual transplantations with guided osteotomies to ensure accurate donor tooth placement in the new recipient site. The 24 months follow-up showed physiological clinical and radiologic results compatible with healing periradicular tissues.

Conclusions

This approach enables the planning and production of a 3D printed surgical template using the latest diagnostic methods and techniques of guided implant surgery. These accurate virtually predesigned surgical templates and printed analogues of the donor tooth could facilitate autotransplantation, ensuring an atraumatic surgical protocol.

The influence of storage temperature on fracture behavior of cryopreserved teeth-An in vitro study

Objectives

Cryopreservation is discussed as a viable method of preserving teeth for determined autogenous tooth transplantation. Unchanged physical properties of hard tooth tissues are crucial for functional healing. Due to different thermal expansion coefficients of enamel and dentin or the crystallization process, the freezing process may lead to crack formation, which could adversely impact the long‐term prognosis of the teeth.

Material and methods

Twenty third molars (n = 20) were frozen slowly using a conservative cryopreservation protocol and stored at −80°C (group 1) and −196°C (group 2). After a storage time of 2 weeks, the samples were thawed to a temperature of +36°C and embedded in polymethyl methacrylate blocks. Cyclic loading was carried out using a spherical steel test specimen with 50,000 mechanical load cycles, followed by load to failure testing for determination of critical load.

Results

No significant difference in the first load drop could be detected during the load to failure test under different storage conditions. The values until fracture correlated very closely in contralateral tooth pairs, which emphasizes the importance of crown geometry in load to failure tests.

Conclusions

Conclusions: Cryopreservation, specifically the storage temperature, does not appear to have a significant effect on the physical properties of tooth transplants.

Autotransplantation of premolars and space closure in a patient with inflamed sinuses

Congenital absence of permanent teeth can be treated by means of dental implants and prosthetics. Tooth autotransplantation is an alternative in growing patients because continued eruption of the transplanted tooth and associated alveolar bone growth can be expected. This clinical report presents tooth autotransplantation in a 10-year-old boy with chronic maxillary rhinosinusitis, diagnosed by the department of otorhinolaryngology. The patient's mandibular second premolars were transplanted to a congenitally edentulous maxillary premolar region. There was insufficient alveolar bone during transplantation because of pneumatization, but normal root development with vertical alveolar bone growth was observed during a 3-year follow-up. Healing of the transplant in the right side without closing of the apex and without signs of obliteration after 4 years is exceptional.

Computer-aided autotransplantation of teeth with 3D printed surgical guides and arch bar: a preliminary experience

Background/Aim

Autotransplantation of teeth is a method to restore the missing teeth and computer-aided techniques have been applied in this field. The aim of this study was to describe a novel approach for computer-aided autotransplantation of teeth and to preliminarily assess its feasibility, accuracy, and stability.

Methods

Eight wisdom teeth with complete root formation of eight adult patients were autotransplanted. Individual replicas of donor teeth with local splints, surgical templates, and arch bars were virtually designed and fabricated using three-dimensional printing, these were then applied in the autotransplantation surgeries. Clinical and radiological outcomes were observed, the extra-alveolar time, success rate, and 1-year survival rate were analyzed, and accuracy and stability of this approach were evaluated.

Results

The extra-alveolar time of donor teeth were less than 3 min. The average follow-up duration was 2.00 ± 1.06 years. All autotransplanted teeth showed normal masticatory function. Ankylosis was found in one patient, and the overall success rate was 87.5%, whereas the 1-year survival rate was 100%. Linear differences between the designed and the immediate autotransplanted positions at crowns and apexes of the donor teeth were 1.43 ± 0.57 and 1.77 ± 0.67 mm, respectively. Linear differences between immediate and the stable positions at crowns and apexes of the donor teeth were 0.66 ± 0.36 and 0.67 ± 0.48 mm, respectively.

Conclusion

The present study illustrated the feasibility, clinical satisfied accuracy, and stability of a novel approach for computer-aided autotransplantation of teeth. This new approach facilitated the surgical procedure and might be a viable and predictable method for autotransplantation of teeth.

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

OBJECTIVES

The objective of this systematic review and meta-analysis was to determine the rates of survival and success and the complications related to autotransplantation of teeth with incomplete root formation. Additionally, we attempted to identify the prognostic factors that influence the outcome of tooth autotransplantation.

MATERIALS AND METHODS

A literature search for all data published until July 2016 was conducted. Inclusion and exclusion criteria were specified. Risk of bias was assessed with the Newcastle checklist. Meta-analysis was performed by using the DerSimonian-Laird random effect model. The 1-, 5-, and 10-year survival rates and the weighted estimated survival, success, and complication rates per year were calculated.

RESULTS

Thirty-two studies were included for analysis. The survival rates reported after 1, 5, and 10 years were 97.4, 97.8, and 96.3%, respectively. The annual weighted estimated survival rate (98.2%), success rate (96.6%), and complication rates in terms of ankylosis (2.0%), root resorption (2.9%), and pulp necrosis (3.3%) were analyzed. No firm conclusions could be drawn with respect to the prognostic factors due to insufficient evidence of high quality.

CONCLUSION

The survival and success rates of autotransplantation of teeth with incomplete root formation were high (> 95%), with a low rate of complications (< 5%).

CLINICAL RELEVANCE

Current evidence from the literature on autotransplantation of teeth with incomplete root formation shows favorable survival and success rates and low complication rates, indicating it is a reliable treatment option.

Autotransplantation of a Premolar with Incipient Root Development, an 18-Year Follow-Up

In young patients, premature tooth loss in the anterior maxilla after trauma is challenging for the patient and the dental professional, with serious implications from aesthetic and functional points of view, as well as from a craniofacial growth aspect perspective. Premolars autotransplanted into the maxillary anterior region have been shown to be a biological alternative in this situation. This report describes the clinical management of a case of premature loss of a maxillary central incisor after traumatic injury. A mandibular premolar at the stage of initial root development was transplanted into the alveolar socket of the lost incisor. After 18 years, the transplanted tooth remained responsive to pulp sensibility tests and the periradicular bone and soft tissues were within normal limits. Autotransplantation of premolar teeth into the maxilla could be considered an excellent treatment choice with many biological advantages over implants or fixed dentures as long as proper case selection is followed.

Survival rate of autotransplanted teeth after 5 years - A retrospective cohort study

BACKGROUND

Autotransplantation of teeth (TX) is a predictable treatment option, although this type of therapy is often overlooked compared to other types of restorations.

PURPOSE

As current literature contains few long-term studies concerning the outcome of autotransplanted immature molars, the aim was to evaluate results after a follow-up period of 5 years.

MATERIAL AND METHODS

This retrospective study enrolled all patients treated with immature autotransplanted molars after a follow-up period of 5 years. In order to ensure comparable results, survival rate was investigated as well as clinical and radiological parameters. Contralateral teeth (TC) were used as controls for further assessments and for ensuring comparable future results.

RESULTS

52 patients with 66 TX were examined. Mean age at the time of surgery was 19.64 years. Tooth survival rate after 5 years was 89.39%. The results for parameters such as PPD, BOP, mobility, dental caries, periapical pathologies and endodontic treatments showed no differences. In contrast, dental restorations (p < 0.001), occlusal contacts (p = 0.003) and sensitivity (p < 0.001) differed significantly between TX and TC.

CONCLUSIONS

The current findings clearly confirm that TX is an effective alternative treatment option to fixed prosthodontic restorations and dental implants, and provides for results equivalent to those with the patients' natural teeth.

Premolar transplantation in a patient with solitary median maxillary central incisor syndrome

This case report describes the orthodontic treatment of an 11-year-old girl with solitary median maxillary central incisor syndrome, a presumed microform of holoprosencephaly. Because both second premolars were missing in the maxilla, deciduous molar extraction and orthodontic space opening were performed, moving the solitary median maxillary central incisor electively off-center. A mandibular second premolar was transplanted to replace the missing incisor. The resulting spaces could be orthodontically closed in both arches. Prosthodontic reshaping of the transplanted tooth after debonding completed the dental treatment.