Outcomes and prognostic factors that influence the success of tooth autotransplantation in children and adolescents

Interdisciplinary management of an adolescent patient with a severely impacted mandibular canine

Impacted mandibular canines often result in a variety of clinical dilemmas. Orthodontic disimpaction of severely displaced mandibular canines may be extremely challenging and associated with significant patient discomfort and a high risk of iatrogenic damage. This case report demonstrates the interdisciplinary management of a horizontally impacted permanent mandibular canine, utilising a combination of three-dimensional radiology, biomodel fabrication and subsequent endodontic treatment. © 2024 Australian Dental Association.

Tooth autotransplantation and resin composite reshaping as a multidisciplinary approach for treating dental agenesia: A 10-year follow-up

CASE REPORT

This case report describes the multidisciplinary approach performed in a 9-year-old male patient with dental agenesia affecting teeth 21 and 22. Autotransplantation of the right upper second premolar with incomplete rhizogenesis to the missing area was combined with coronary reshaping with resin composite and orthodontic therapy. The treatment began with the extraction of the deciduous upper left central incisor, bone preparation for the recipient site of the donor tooth, atraumatic extraction of the right upper second premolar and immediate autotransplantation in the surgically prepared recipient site. Subsequently, sutures to reposition the flap and a rigid splint were performed. After 12 months, coronary reshaping of the autotransplanted tooth with resin composite was carried out. Orthodontic treatment involving the use of a fixed appliance was used to correct the interdental spaces and achieve adequate occlusion. Clinical and radiographic follow-up 10 years after tooth autotransplantation and 9 years after reshaping revealed partial obliteration of the pulp chamber, root resorption, ankylosis and the presence of endodontic treatment.

CONCLUSIONS

The long-term outcomes highlighted that tooth autotransplantation represents a biologically and cost-effective procedure for replacing missing teeth in young patients, particularly in cases of incomplete rhizogenesis of the autotransplanted tooth.

CLINICAL SIGNIFICANCE

This case report discusses tooth autotransplantation and resin composite reshaping as viable and long-term clinical options for treating young patients with dental agenesis.

Knowledge, attitudes, and practices among patients with combined dentition defect and non-functional impacted teeth toward tooth autotransplantation

BACKGROUND

Tooth autotransplantation (TAT) is a surgical procedure involving the extraction of a tooth from one location and its subsequent transplantation into another alveolar socket within the same individual. This innovative treatment approach holds significant promise. Nonetheless, the potential recipients exhibit a limited level of awareness and understanding of this procedure. This study investigated the knowledge, attitudes, and practices (KAP) among patients with combined dentition defects and non-functional impacted teeth toward TAT.

METHODS

This web-based cross-sectional study was conducted between December 2022 and February 2023 at one hospital. A self-designed questionnaire was developed to collect demographic information of the patients and assess their knowledge, attitudes, and practices toward TAT.

RESULTS

A total of 533 valid questionnaires were collected. The mean knowledge, attitude, and practice scores were 5.55 ± 2.38 (possible range: 0-10), 26.82 ± 2.46 (possible range, 8-40), and 27.45 ± 7.40 (possible range, 9-45), respectively.

CONCLUSION

The participants had insufficient knowledge, negative attitudes, and passive practices toward TAT. Targeted interventions should be implemented to improve the understanding and practice of TAT among patients with dentition defects.

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.

AUTOTRANSPLANTATION OF TEETH WITH OPEN APICES MAY RESULT IN HIGH SURVIVAL RATES BUT EVIDENCE IS LIMITED

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Tooth autotransplantation: an umbrella review. Tan BL, Tong HJ, Narashimhan S, Banihani A, Nazzal H, Duggal MS. Dent Traumatol 2023;39(Suppl 1):2-29.

SOURCE OF FUNDING

Open access funding provided by the Qatar National Library TYPE OF STUDY/DESIGN: Umbrella review.

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.

Anterior 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. It is relatively common for the anterior segment of the mouth to be affected by traumatic tooth injuries, impacted and/or congenitally missing permanent teeth. Autotransplantation of teeth into the anterior dental arch can provide unrivalled biological solutions when such issues arise in this critical aesthetic zone, particularly for adolescent patients. The combination of meticulous pre-surgical assessment, synergistic interdisciplinary collaboration and carefully performed anterior tooth autotransplantation has been demonstrated to achieve impressive outcomes, with respect to both transplant survival and clinical success. © 2023 Australian Dental Association.

Tooth autotransplantation: An umbrella review

Tooth autotransplantation is a versatile procedure with several clinical applications among patients across different age groups. The success of this procedure depends on multiple factors. Despite the wealth of studies available, no single primary study or systematic review is able to report on every factor affecting the outcomes of autotransplantation. The aims of this umbrella review were to evaluate treatment-related and patient-related outcomes of autotransplantation and to assess the pre-, peri- or post-operative factors that could affect these. An umbrella review was conducted according to the PRISMA statement. A literature search of five databases was performed up to 25 September 2022. Systematic Reviews (SR) with and without meta-analysis evaluating autotransplantation were included. Calibration among reviewers was carried out prior to study selection, data extraction and Risk of Bias (RoB) assessment. Study overlap was calculated using corrected covered area. Meta-meta-analysis (MMA) was performed for suitable SRs. The AMSTAR 2 critical appraisal tool was used to evaluate the quality of evidence. Seventeen SRs met the inclusion criteria. Only two SRs were suitable for conduct of MMA on autotransplantation of open apex teeth. The 5-year and 10-year survival rates were >95%. A narrative summary on factors that could affect autotransplantation outcomes and comparisons of autotransplantation to other treatment options were reported. Five SRs were rated as 'low quality' and 12 SRs were rated as 'critically low quality' in the AMSTAR 2 RoB assessment. In order to facilitate a more homogenous pool of data for subsequent meta-analysis, an Autotransplantation Outcome Index was also proposed to standardise the definition of outcomes. Autotransplantation of teeth with open apices have a high survival rate. Future studies should standardise the reporting of clinical and radiographic findings, as well as the definition of outcomes.

Accuracy of CAD-CAM surgically guided tooth autotransplantation using guided templates and custom-designed osteotomes in human cadaver mandibles

INTRODUCTION

A major challenge in dentistry is the replacement of teeth lost prematurely due to trauma, caries, or malformations, especially in growing patients. The aim of this study was to assess the accuracy of CAD-CAM surgically guided tooth autotransplantation in cryopreserved cadaver mandibles using guided templates and custom-designed osteotomes.

METHODS

Cryopreserved human cadaver heads were digitized and scanned using an intraoral optical scanner and a large-volume cone beam computed tomography (CBCT) device. First, virtual surgical planning was performed to create a 3D tooth replica, two surgical guides, and a custom-made osteotome for each single-rooted tooth autotransplantation procedure/case. Surgical sockets were created in the selected mandibles using guided tooling consisting of an initial guided osteotomy with implant burs and a final guided osteotomy using custom osteotomes. After tooth autotransplantation, second large-volume CBCT images of the five cadaver mandibles were obtained. The discrepancy in mm within the 3D space (apical and mesiodistal deviations) between the final position of the autotransplanted teeth and their digitally planned 3D initial position was calculated and analyzed statistically (P< .05).

RESULTS

All donor teeth were placed without incident within their newly created sockets in the real mandibles. The mean difference between the digitally planned root apex position and the final tooth position was 2.46±1.25mm. The mesiodistal deviation of the autotransplanted teeth was 1.63±0.96mm.

CONCLUSIONS

The autotransplantation of single-rooted teeth with custom-designed and 3D-printed surgical tooling provided promising results. The technique was able to create surgically prepared sockets that could accommodate transplanted teeth in mandibles.

Multimodal Imaging of Dental Pulp Healing Patterns following Tooth Autotransplantation And Regenerative Endodontic Treatment

INTRODUCTION

Understanding the healing process of dental pulp after tooth autotransplantation (TAT) and regenerative endodontic treatment (RET) of immature teeth is important both clinically and scientifically. This study aimed to characterize the pattern of dental pulp healing in human teeth that underwent TAT and RET using state-of-the-art imaging techniques.

MATERIALS AND METHODS

This study examined four human teeth, two premolars that underwent TAT and two central incisors that received RET. The premolars were extracted after one year (case 1) and two years (case 2) due to ankylosis, while the central incisors were extracted after three years (cases 3 and 4) for orthodontic reasons. Nanofocus x-ray computed tomography was used to image the samples before being processed for histological and immunohistochemical analysis. Laser scanning confocal second harmonic generation imaging (SHG) was used to examine the patterns of collagen deposition. A maturity-matched premolar was included as a negative control for the histological and SHG analysis.

RESULTS

Analysis of the four cases revealed different patterns of dental pulp healing. Similarities were observed in the progressive obliteration of the root canal space. However, a striking loss of typical pulpal architecture was observed in the TAT cases, while a pulp-like tissue was observed in one of the RET cases. Odontoblast-like cells were observed in cases 1 and 3.

CONCLUSION

This study provided insights into the patterns of dental pulp healing after TAT and RET. The SHG imaging sheds light on the patterns of collagen deposition during reparative dentin formation.

An evaluation of 1654 premolars transplanted in the posterior region-A retrospective analysis of survival, success and complications

AIM

The aim of this retrospective analysis was to evaluate the survival, success and possible complications of transplanted premolars in the posterior region subdivided by developmental stage and patient age.

MATERIALS AND METHODS

This study included patients who underwent tooth transplantation between April 2004 and December 2021. A total of 1654 premolars were transplanted into 1243 patients. Tooth mobility, oral hygiene and periodontal parameters were clinically evaluated. Intraoral radiographs were used to evaluate pulpal and periodontal healing, and root formation. The cumulative survival rate was calculated using the Kaplan-Meier method.

RESULTS

Data were subdivided into three groups based on the stage of root development and patient age. The mean age at surgery was 14.5 years. The main indication for transplantation was agenesis, followed by trauma and other indications, such as impacted or malformed teeth. A total of 11 premolars were lost during the study period. The overall survival and success rates in the immature premolar group after an observation period of 10 years were 99.7% and 99.4%, respectively. High survival and success rates (95.7% and 95.5%, respectively) were also observed when fully developed premolars were transplanted into the posterior region of adolescents. In adults, the success rate after 10-year follow-up is 83.3%.

CONCLUSIONS

Transplantation of premolars with developing and fully developed roots is a predictable treatment modality.

Pulp revascularization after autotransplantation of the mandibular canines with partially resected roots. Report of five cases with follow-ups between 26 and 80 months

INTRODUCTION

Transmigrated (migrated through the midline) mandibular canines constitute a treatment challenge. Advanced transmigration can be successfully treated by autotransplantation. In developing canines, pulp revascularisation is typical after transplantation. On the contrary, the pulp of teeth with completed apex formation does not undergo revascularization. In this case, root canal treatment becomes compulsory and decreases the success of autotransplantation. The aim of this observational retrospective study was to evaluate whether partial resection of the root (performed during the autotransplantation of mature canines) would enable revascularization of the pulp after the surgery.

METHODS

Five transmigrated mandibular canines with complete apex formation before the surgery were evaluated. During the autotransplantation surgery, the resection of 2-4 mm of the root apex was performed to open the path for revascularisation of the pulp after surgery. The transplanted teeth were observed during healing after the surgery for the presence of pulp obliteration. Clinical and radiographic examinations were performed.

RESULTS

All treated canines survived the minimum observation period of two years (ranging from 26 to 80 months, mean: 55 months) without pulp healing complications. The survival was 100 percent, and the success was 80 percent. In one canine, the external cervical root resorption was diagnosed and treated one year after the surgery. At the final examination, transplanted canines presented radiographic features of pulp obliteration, normal mobility, and healthy periodontal tissues.

CONCLUSIONS

The surgical protocol proved to be successful in promoting revascularization to maintain pulp vitality, in all cases. The outcomes confirm that autotransplantation, combined with the resection of the root, constitutes as a valid treatment for mature ectopic canines.

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 auto-transplantation: A bibliometric analysis of the top 100 most-cited articles

BACKGROUND/AIM

Tooth auto-transplantation has recently gained high clinical acceptance. The aim of this study was to identify the top 100 most-cited articles regarding tooth auto-transplantation, to analyse multiple citations and publication metrics and to outline the historical scientific advancements in this field.

MATERIALS AND METHODS

An advanced search of the Clarivate Analytics' Web of Science 'Core Collection' and Elsevier's Scopus databases utilising specific keywords related to tooth auto-transplantation between 1971 and 2021 was performed. The retrieved articles were ranked in descending order based on their Web of Science citation counts and further cross-matched with citation data from Scopus. The extracted data included citation counts, citation density, level of evidence, year of publication, contributing authors names and institutes, corresponding author's address, journal of publication, journal local citations index, cumulative growth index, keywords and keywords Plus. Data analysis was performed using descriptive statistics and graphical mapping.

RESULTS

A total of 1290 articles were retrieved. The top 100 most-cited articles received a total of 4899 (Web of Science) and 5250 (Scopus) citations. Among these, cohort studies (29%) and case series (18%) were the most common study designs. Scandinavian countries produced major contributions in defining the top 100 most-cited articles and ranked within the top 5 countries based on the number of publications and citations per year. The greatest contributing authors were Schwartz O (n = 12), Andreasen JO (n = 8) and Paulsen HU (n = 6), and they were affiliated with Copenhagen, Denmark. The top contributing journals were American Journal of Orthodontics and Dentofacial Orthopedics, International Journal of Oral and Maxillofacial Surgery, Oral Surgery Oral Medicine Oral Pathology Oral Radiology, European Journal of Orthodontics, Dental Traumatology and Journal of Oral and Maxillofacial Surgery.

CONCLUSION

This bibliometric analysis revealed a large geographical scientific interest and broad development in the field of tooth auto-transplantation spanning multiple dental disciplines.

Extraoral Root-End Resection May Promote Pulpal Revascularization in Autotransplanted Mature Teeth-A Retrospective Study

Tooth germ autotransplantation of open apices of the teeth exhibits high pulpal healing rates, whereas that of mature permanent teeth normally causes irreversible pulpal necrosis. Extraoral root-end resection (EORER) during transplantation may promote pulpal revascularization (PRV) in transplanted mature teeth and reduce endodontic treatment requirement. This study compared the primary outcomes of survival rates, PRV, and root resorption and determined relevant confounders in autotransplanted mature and immature teeth. The medical charts of consecutive patients who underwent tooth autotransplantation between January 2017 and March 2021 were evaluated. Teeth with a documented follow-up of at least 1 year were included. During the study period, 59 teeth were transplanted in 44 patients. Overall, 2 teeth were excluded owing to missing data; 57 teeth were analyzed, including 25 mature teeth additionally treated with EORER. After a mean follow-up of 21.2 ± 16.1 months, no significant differences in primary outcomes were detected. Fifty-five teeth remained in situ (96.5%), and radiological signs of root resorption were detected in 9/57 teeth (15.8%). PRV was positive in 54/57 teeth (94.7%). Surgical duration and PRV failure were significantly associated with high incidences of root resorption. Mature teeth autotransplantation with EORER yielded similar results to immature teeth autotransplantation and is a feasible treatment option. Long surgery and failed revascularization increased root resorption rates. More factors should be evaluated in larger trials with longer observation periods.

Role of osteopontin in the process of pulpal healing following tooth replantation in mice

Introduction

The role of osteopontin (OPN) following severe injury remains to be elucidated, especially its relationship with type I collagen (encoded by the Col1a1 gene) secretion by newly-differentiated odontoblast-like cells (OBLCs). In this study, we examined the role of OPN in the process of reparative dentin formation with a focus on reinnervation and revascularization after tooth replantation in Opn knockout (KO) and wild-type (WT) mice.

Methods

Maxillary first molars of 2- and 3-week-old-Opn KO and WT mice (Opn KO 2W, Opn KO 3W, WT 2W, and WT 3W groups) were replanted, followed by fixation 3–56 days after operation. Following micro-computed tomography analysis, the decalcified samples were processed for immunohistochemistry for Ki67, Nestin, PGP 9.5, and CD31 and in situ hybridization for Col1a1.

Results

An intense inflammatory reaction occurred to disrupt pulpal healing in the replanted teeth of the Opn KO 3W group, whereas dental pulp achieved healing in the Opn KO 2W and WT groups. The tertiary dentin in the Opn KO 3W group was significantly decreased in area compared with the Opn KO 2W and WT groups, with a significantly low percentage of Nestin-positive, newly-differentiated OBLCs during postoperative days 7–14. In the Opn KO 3W group, the blood vessels were significantly decreased in area and pulp healing was disturbed with a failure of pulpal revascularization and reinnervation.

Conclusions

OPN is necessary for proper reinnervation and revascularization to deposit reparative dentin following severe injury within the dental pulp of erupted teeth with advanced root development.

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Osteopontin deficiency inhibits hard tissue formation in advanced erupted teeth.

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Odontoblast-like cells may be different origins between mild and severe injuries.

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Osteopontin has an important role for proper reinnervation and revascularization.

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Osteopontin is necessary to deposit reparative dentin in advanced erupted teeth.

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.

Tooth transplantation and replantation: Biological insights towards therapeutic improvements

Transplantation and replantation of teeth are effective therapeutic approaches for tooth repositioning and avulsion, respectively. Transplantation involves transplanting an extracted tooth from the original site into another site, regenerating tissue including the periodontal ligament (PDL) and alveolar bone, around the transplanted tooth. Replantation places the avulsed tooth back to its original site, regenerating functional periodontal tissue. In clinical settings, transplantation and replantation result in favorable outcomes with regenerated PDL tissue in many cases. However, they often result in poor outcomes with two major complications: tooth ankylosis and root resorption. In tooth ankylosis, the root surface and alveolar bone are fused, reducing the PDL tissue between them. The root is subjected to remodeling processes and is partially replaced by bone. In severe cases, the resorbed root is completely replaced by bone tissue, which is called as "replacement resorption." Resorption is sometimes accompanied by infection-mediated inflammation. The molecular mechanisms of ankylosis and root resorption remain unclear, although some signaling mechanisms have been proposed. In this mini-review, we summarized the biological basis of repair mechanisms of tissues in transplantation and replantation and the pathogenesis of their healing failure. We also discussed possible therapeutic interventions to improve treatment success rates.

Combined Application of Virtual Simulation Technology and 3-Dimensional-Printed Computer-Aided Rapid Prototyping in Autotransplantation of a Mature Third Molar

The use of computer-aided rapid prototyping (CARP) models was considered to reduce surgical trauma and improve outcomes when autotransplantation of teeth (ATT) became a viable alternative for dental rehabilitation. However, ATT is considered technique-sensitive due to its series of complicated surgical procedures and unfavorable outcomes in complex cases. This study reported a novel autotransplantation technique of a 28-year-old patient with an unrestorable lower first molar (#36) with double roots. Regardless of a large shape deviation, a lower third molar (#38) with a completely single root formation was used as the donor tooth. ATT was performed with a combined use of virtual simulation, CARP model-based rehearsed surgery, and tooth replica-guided surgery. A 3D virtual model of the donor and recipient site was generated from cone-beam computed tomographic (CBCT) radiographs prior to surgery for direct virtual superimposition simulation and CARP model fabrication. The virtual simulation indicated that it was necessary to retain cervical alveolar bone during the surgical socket preparation, and an intensive surgical rehearsal was performed on the CARP models. The donor tooth replica was used during the procedure to guide precise socket preparation and avoid periodontal ligament injury. Without an additional fitting trial and extra-alveolar storage, the donor tooth settled naturally into the recipient socket within 30 s. The transplanted tooth showed excellent stability and received routine root canal treatment three weeks post-surgery, and the one-year follow-up examination verified the PDL healing outcome and normal functioning. Patient was satisfied with the transplanted tooth. This cutting-edge technology combines virtual simulation, digital surgery planning, and guided surgery implementation to ensure predictable and minimally invasive therapy in complex cases.

Supernumerary tooth autotransplantation to replace missing maxillary central incisor using three-dimensional replica: A 6-year follow-up

INTRODUCTION

Tooth autotransplantation is a viable surgical treatment option for patients with missing permanent teeth. Premolars are generally used for autotransplantation but often require extensive modifications. This case report evaluates the use of supernumerary tooth as an alternative option for premolar autotransplantation. This report shows successful supernumerary tooth autotransplantation with 6-year follow-up.

METHODS

A 13-year-old male with non-contributory medical history was referred for a missing maxillary left central incisor (#9) and presence of a supernumerary tooth. The clinical and radiographic examination revealed presence of supernumerary tooth with similar dimensions to a central incisor. The treatment plan included autotransplantation of the supernumerary tooth to replace the missing central incisor (short-term) and future implant replacement of the autotransplanted tooth when jaw growth ceases (long-term). The patient and parents consented to treatment. A 3-D tooth replica was constructed based on CBCT analyses. Site #9 was prepared using split ridge technique to create a socket to house the 3-D replica. Upon achieving proper socket form, the supernumerary tooth was extracted and autotransplanted in the prepared socket. The supernumerary tooth was splinted, and the bite opened posteriorly using composite to eliminate any occlusal interferences.

RESULTS

The patient was followed up clinically and radiographically. The autotransplanted supernumerary tooth integrated well within the newly created socket and remained functional at the 6-year follow-up.

CONCLUSIONS

The current case presents successful management of supernumerary tooth autotransplantation with 6-year follow-up. The results show stable periodontium with satisfactory functional and aesthetic results.

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.

Three-Dimensional (3D) Stereolithographic Tooth Replicas Accuracy Evaluation: In Vitro Pilot Study for Dental Auto-Transplant Surgical Procedures

After immediate tooth extraction or after alveolar socket healing, tooth transplants are increasingly used for functional restoration of edentulous maxillary areas. Recent studies have shown the periodontal ligament (PDL) viability and the tooth housing time in the adapted neo-alveolus as key factors for transplantation success. During surgical time, 3D stereolithographic replicas are used for fitting test procedures. In this paper, the accuracy of 3D dental replicas, compared with the corresponding natural teeth, is assessed in surgical transplantation. Lamb skulls were selected and submitted to Cone Beam Computer Tomography (CBCT). Scanning information, converted into Standard Digital Imaging and Communications in Medicine (DICOM) and Standard Triangulation Language (STL), was sent to the Volux X-ray Centre for 3D replica printing. After the tooth extractions, all lambs’ incisors were measured with a digital caliber and compared with the 3D replicas. Volume and dimensional error values were evaluated. All replicas showed macroscopically smaller volume (45.54%). Root replicas showed higher variations compared with the crown areas, with several unreplicated apical root areas. The cement–enamel junction tooth area was replicated quite faithfully, and the base area relative error showed 9.8% mean value. Even further studies with a larger number of replicas are needed. Data obtained confirmed high volumes of macroscopic discrepancies with several unreproduced apical root sites. The achieved accuracy (90.2%) confirmed that the 3D replicas cannot be used to reduce the surgical time during transplantation predictable procedures.

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.

Influence of Static Navigation Technique on the Accuracy of Autotransplanted Teeth in Surgically Created Sockets

The aim of this study was to analyse and compare the position of single-rooted autotransplanted teeth using computer-aided SNT drilling and conventional freehand (FT) drilling, by comparing the planned and performed position at the coronal, apical and angular level. Materials and methods: Forty single-root upper teeth were selected and distributed into the following study groups: A. Autotransplanted tooth using the computer-aided static navigation technique (SNT) (n = 20) and B. Autotransplanted tooth using the conventional free-hand technique (FT) (n = 20). Afterwards, the teeth were embedded into two experimental models and 10 single-root upper teeth were randomly autotransplanted in each experimental model. The experimental models were submitted to a preoperative cone-beam computed tomography (CBCT) scan and a digital impression by a 3D intraoral scan, in addition to a postoperative CBCT scan, after the autotransplantation. Datasets from postoperative CBCT scans of the two study groups were uploaded to the 3D implant planning software, aligned with the autotransplantation planning, and the coronal, apical and angular deviations were measured. The results were analysed using Student’s t-test and Mann–Whitney non-parametric statistical analysis. Results: Coronal (p = 0.079) and angular (p = 0.208) statistical comparisons did not present statistically significant differences; however, statistically significant differences between the apical deviation of the SNT and FT study groups (p = 0.038) were also observed. Conclusions: The computer-aided static navigation technique does not provide higher accuracy in the positioning of single-root autotransplanted teeth compared to the conventional free-hand technique.

Decoronation - a treatment option of an ankylosed permanent tooth in children and adolescents

Introduction. In children and growing adolescents, ankylotic resorption (i.e., progressive replacement resorption) of a permanent tooth is a serious complication. An ankylosed tooth root is continuously resorbed and replaced with bone; normal growth of alveolar bone is disturbed and infraposition of the dental crown progresses. This article aims to present decoronation as a very good treatment option for permanent incisors diagnosed with progressive replacement resorption in children and adolescents. Case outline. A 9.5-year-old boy was referred with non-vital both upper central permanent incisors due to dental trauma. In the left one, which had been re-implanted 90 minutes after avulsion, progression of clinical and radiographic pathological signs of ankylotic resorption was observed over the months. To prevent the local arrest of alveolar ridge growth and tilting of adjacent teeth, we decoronated the ankylosed tooth. For aesthetic and functional rehabilitation adhesive bonding of his dental crown was performed. Conclusion. In growing individuals with progressive replacement resorption, a dentist should be aware of decoronation as an effective treatment option with a predictable outcome.

Impacted maxillary canine with curved apex: Three-dimensional guided protocol for autotransplantation

INTRODUCTION

Maxillary canines play a crucial role in dental and facial aspect, arch expansion, and efficient occlusion. When surgical exposure measures cannot be executed or the patient does not agree to take the treatment, autotransplantation should be considered. The aim of this case report was to describe a novel surgical technique using virtually planned three-dimensional(3D)-printed templates for guided apicoectomy and guided drilling of the recipient site for an autotransplantation of an impacted maxillary canine with a curved apex.

METHODS

A 42-year-old male complaining of pain and increased mobility in the maxillary left primary canine came to the clinic. Autotransplantation of the impacted canine was completed using altered methods from guided implant surgery to manufacture 3D-printed templates. Following a full-thickness mucoperiosteal flap elevation, the surgical template for the guided osteotomy and apicoectomy was inserted. This 3D-printed guided allowed the clinician to perform a quick and precise removal of the curved apex, providing an atraumatic extraction of the impacted canine throughout the cyst. Three further 3D surgical guides for implant burs and a 3D replica tooth were printed to modify the recipient socket. After the final position, the tooth was semi-rigid splinted to the adjacent teeth.

RESULTS

Follow-up at 2 years showed complete regeneration of the palatal defect and remodeling of the bone surrounding the maxillary canine.

CONCLUSIONS

Digitally planned procedures can facilitate the complex execution of an autotransplantation reducing the treatment chair-time and the morbidity for the patient as well as increasing the predictability of the result.

Application of concentrated growth factor to autotransplantation with inflammation in recipient area

OBJECTIVE

The purpose of this study was to apply concentrated growth factor (CGF) to the transplanted area with inflammation, to observe the clinical effects of CGF on the inflammation area assisted by 3D printing technology.

METHODS

A total of 52 compromised mandibular first or second molar with chronic periapical lesions were transplanted with mature third molars. The patients were divided into CGF group (n = 26) and control group (n = 26) and transplanted into fresh extraction sockets with or without CGF. All the patients underwent clinical and radiographic examinations during the follow-up.

RESULTS

Average surgery and extra-oral time were 39 min (± 7.8) and 42 s (± 10.2). The success rates of CGF group and control group were 100% and 92.3% respectively. Most of the periapical lesions in CGF group healed completely within 3 months, which was significantly faster than control group. The initial stability of CGF group was better than control group immediately after operation, and the degree of pain in CGF group was lower than control group on the 1st and 3rd day after operation.

CONCLUSIONS

The application of CGF in recipient site with chronic periapical lesions can accelerate the regeneration of alveolar bone and the healing of inflammation, greatly shorten the healing period. Meanwhile, CGF help to reduce postoperative pain and reaction at the early stage of healing and increase the success rate of autogenous tooth transplantation (ATT). Additionally, the use of 3D printing model can greatly reduce the extra-oral time of donor teeth.

An interdisciplinary approach to orthodontic treatment of a mutilated Class III malocclusion with mini-implants, dental implants, and an autotransplant

This case report demonstrates the interdisciplinary treatment of a 24-year-old female. Her skeletal discrepancy, anterior crossbite, mutilated dentition, and midline deviation made it challenging to achieve satisfactory treatment results, especially without major orthognathic surgery. This article thoroughly discusses the decision-making process associated with various treatment alternatives, the biomechanical considerations with temporary skeletal anchorage devices, and the detailed operational process of dental implant restoration and autotransplantation. CLINICAL SIGNIFICANCE: Orthodontic treatment aims to obtain better facial and dental esthetics, achieve functional occlusion, and improve oral health. Treatment of patients with a mutilated dentition requires interdisciplinary teamwork from a group of professionals with various types of expertise. Orthodontists should be the navigator that generates the tooth movement and space redistribution, thus facilitating the subsequent functional rehabilitation under a well-organized occlusal architecture. Autotransplantation offers an economical and biologically-friendly opportunity to replace a missing tooth.

Pre- and peri-operative factors influence autogenous tooth transplantation healing in insufficient bone sites

Background

The amount of bone remaining at the transplant site for autogenous tooth transplantation can facilitate successful healing. Therefore, this retrospective study evaluated the factors influencing the healing of 50 successful autogenous tooth transplantations with insufficient bone support at the transplanted site without a bone graft.

Methods

The factors were classified as pre- and peri-operative factors, and the healing outcomes were clinical and radiographic observations. The factors were statistically analyzed using the chi-square test to identify correlations between the pre- and peri-operative factors and the clinical and radiographic outcomes. The T-test or one-way analysis of variance was used to compare the percent bone change in each factor.

Results

The results indicated that gingival healing was delayed in the intra-arch transplantations, and pulp obliteration was seen earlier when transplanted in the maxilla. Patients under 18-years-old demonstrated a greater percent bone change than the over 18-year-old patients, while the peri-operative variables did not have a relationship with clinical healing and the amount of bone change over 12 months. Furthermore, the percent bone change significantly increased during the first three months.

Conclusions

In conclusion, pre-operative factors, age and transplant site, influenced the healing rate of autogenous transplanted teeth. In contrast, the peri-operative factors were not related with the clinical and radiographic outcomes. Generating the least trauma to the periodontal ligament cells is the most important concern.

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 conservative approach for an adult patient with a fractured tooth and crowding: Autotransplantation at the fracture site

Autotransplantation of a mature premolar in adults can be a treatment of choice for tooth replacement when combined with well-planned orthodontic treatment. This case report describes the successful treatment of a 39-year-old patient with severe crowding and a hopelessly fractured tooth on the maxillary left side. Maxillary dental crowding was relieved by extraction of a premolar on the right side, and this extracted tooth was autotransplanted to replace the fractured tooth. A mandibular incisor was extracted to correct anterior crossbite. The total treatment period was 20 months. The treatment results showed a good long-term prognosis after transplantation of a mature premolar with normal surrounding alveolar bone level for over 6 years of follow-up. Occlusion and periodontal health were excellent in the long term.

Effect of Root Canal Therapy on the Success Rate of Teeth with Complete Roots in Autogenous Tooth Transplantation

BACKGROUND

Autogenous tooth transplantation is a reliable method for repairing missing teeth. Although it recently became a recognized and feasible treatment method in dentistry, the long-term efficacy of root canal therapy (RCT) has not been well confirmed. This study is aimed at determining whether RCT has a good effect on the success rate of teeth with complete roots in autogenous tooth transplantation.

MATERIALS AND METHODS

Data were collected from the Korea University Guro Hospital. Data of patients who underwent autogenous tooth transplantation within 9 years were collected. We selected 29 teeth with complete roots as the research subjects in our study. None of the patients had any systemic diseases. All cases in this study were obtained with patient permission.

RESULTS

According to the tooth vitality test, the autogenous teeth tested negative in dental pulp test and function. Nine of the 29 teeth with autogenous tooth transplantation were treated with RCT and survived throughout the observation period. However, 20 autogenous teeth were not treated with RCT, and eight of them did not survive. All statistical analyses were performed using IBM SPSS 20.0. The null hypothesis was rejected (p < 0.05).

CONCLUSION

For complete root teeth, the success rate after autogenous tooth transplantation after RCT is higher than that of teeth not treated with RCT.

Success, Survival Rate, and Soft Tissue Esthetic of Tooth Autotransplantation

INTRODUCTION

The aim of this retrospective study was to assess the success, survival rate, and soft tissue esthetic of autotransplanted teeth.

METHODS

This study included patients with at least 1 tooth autotransplanted to the maxilla during childhood or adolescence. The autotransplantation technique included the removal of an immature tooth from a donor site and its placement in the maxilla as a replacement for a missing or extremely compromised tooth. The cases were properly restored to ensure function and esthetic. To be considered successful, the tooth should be asymptomatic at the time of assessment, no pain to palpation and percussion, have no signs of apical periodontitis or a sinus tract, have a periodontal probe ≤3, and have an absence of root resorption and development of at least 70% of the normal root. The esthetic evaluation of the soft tissue was based on the pink esthetic score and graded as very unsatisfactory, unsatisfactory, poor, fair, good, or excellent. Data were statistically analyzed at a significance level of 5%.

RESULTS

Thirty-five patients (23 males and 12 females) had 43 anterior teeth replaced, including 42 central incisors and 1 lateral incisor. The follow-up period ranged from 1-25 years. In regard to success and the survival rate, 43 teeth were assessed; 34 cases (79.07%) were considered successful and 9 (20.93%) unsuccessful. Only 1 tooth was lost, and 42 teeth remained functional (survival rate = 97.67%). In regard to the esthetic, 40 teeth could be assessed and were considered as excellent (30%), good (35%), fair (27.5%), and poor (7.5%); there were no reports of unsatisfactory or very unsatisfactory cases.

CONCLUSIONS

Tooth autotransplantation can be considered a valid procedure to replace lost teeth in the maxilla, presenting high survival and success rates. The overall esthetic of the patients was considered as satisfactory.

The use of 3D additive manufacturing technology in autogenous dental transplantation

Background

In medicine and dentistry, 3D technology allows the virtual planning and printing of surgical replicas of anatomical structures that can facilitate certain transplant procedures. In dentistry, 3D technology is useful in autogenous tooth transplantation.

Case presentation

We present a clinical case of an ectopic mandibular second premolar, describing the preoperative planning with dental replicas and the autotransplantation surgery. 3D prints of the surgical replica of the tooth to be transplanted was made using an Objet30 Prime® Printer, PolyJet. Clinical controls performed at 3, 6 and 12 months indicated the satisfactory evolution of the transplanted tooth.

Conclusion

3D additive manufacturing technology allows the preparation of a new recipient socket with the aid of a surgical replica of the tooth to be transplanted, thus minimizing handling and extraoral time.

Survival of Autotransplanted Teeth With Open Apices: A Retrospective Cohort Study

PURPOSE

Autotransplantation of teeth is an alternative treatment method in growing patients with hypodontia or impacted teeth. The purpose of the present study was to investigate the occurrence of, and predictors for, the loss of transplanted teeth in children and young adults.

PATIENTS AND METHODS

All patients who had undergone tooth transplantation at the Department of Oral and Maxillofacial Surgery, Turku University Hospital, from October 1, 2009 to January 5, 2017, were identified from the hospital's database. The outcome variable was survival of the transplanted tooth. The predictor variables were the transplantation type, donor tooth, maturity of the donor tooth, number of roots of the donor tooth, recipient's jaw, the need for extraoral storage of the donor tooth during surgery, continuation of root development during follow-up, and institution experience. One tooth was randomly selected from each subject. The Kaplan-Meier method for survival analysis, and the Cox proportional hazards regression analysis results were used to assess the association between survival and the risk factors.

RESULTS

The sample included 36 subjects with a mean age of 14.3 years; 33.3% were male, 45 teeth were transplanted, and the median follow-up time was 1.3 years. The 1-year survival rate was 87% (95% confidence interval [CI], 75 to 99%). A significant predictor for tooth survival was the continuation of root development (hazard ratio, 21.3; 95% CI, 2.1 to 215.0; P = .009). Although not statistically significantly, more favorable prognoses were found for distant than for transalveolar transplantations, 1-rooted than multirooted teeth, premolars than molars, teeth not stored in an extraoral media, and teeth that had been transplanted later during the study period.

CONCLUSIONS

The experience of the professional team, use of open apex premolars, and postoperative continuation of root development of the transplant were the factors associated with favorable outcomes. Transplants could benefit from the use of 3-dimensional models during surgery.

Poly lactic-co-glycolic acid scaffold loaded with plasmid DNA encoding fibroblast growth factor-2 promotes periodontal ligament regeneration of replanted teeth

OBJECTIVE

This study investigated the effects of poly lactic-co-glycolic acid (PLGA) loaded with plasmid DNA encoding fibroblast growth factor-2 (pFGF-2) on human periodontal ligament cells (hPDLCs) in vitro and evaluated the ability of the PLGA/pFGF-2 scaffold to promote periodontal ligament (PDL) regeneration in a beagle dog teeth avulsion animal model.

BACKGROUND

Growth factor and scaffold play important roles in PDL regeneration. PLGA is a kind of biodegradable and biocompatible polymer that can be used as a carrier to deliver growth factors or genes. FGF-2 can induce potent proliferative responses, promote cell migration and regulate the production of extracellular matrix. Therefore, a gene-activated matrix composed of scaffold and genes is supposed to be a superior approach for promoting tissue regeneration.

METHODS

In this study, PLGA and PLGA/pFGF-2 scaffolds were fabricated using electrospinning. The characterization of scaffolds was shown by scanning electron microscope (SEM) and transmission electron microscope (TEM). dsDNA HS was used to test the plasmid release of PLGA/pFGF-2 scaffold. The viability and proliferation of hPDLCs on the two kinds of scaffolds were evaluated by the CCK-8 assay, and the expression of collagen I and scleraxis were analysed by RT-qPCR. The roots of avulsed teeth were covered by the two types of scaffolds and replanted into the alveolar pockets in beagles. Haematoxylin-eosin and Masson staining were used to evaluate the effects of PLGA/pFGF-2 scaffold on promoting PDL regeneration.

RESULTS

The smooth and uniform fibres can be observed in both scaffolds, and the plasmids were randomly distributed in the PLGA/pFGF-2 scaffold. dsDNA HS analysis demonstrated that the PLGA/pFGF-2 scaffold released up to 123 ng pFGF-2 over 21 days in a sustained manner without any obvious burst release. The PLGA/pFGF-2 scaffold promoted the proliferation of hPDLCs and increased the expression levels of collagen I and scleraxis compared with PLGA scaffold. Animal experiments showed that more regular PDL-like tissues and less root surface resorption occurred in the PLGA/pFGF-2 scaffold group compared with the PLGA scaffold group.

CONCLUSIONS

The PLGA/pFGF-2 scaffold promoted hPDLCs proliferation and facilitated periodontal ligament-related differentiation. The PLGA/pFGF-2 scaffold possesses excellent biological characteristics and could be used as a promising biomaterial for improving the treatment prognosis of replanted tooth.

Autotransplantation of a surgically removed canine using a customised 3D-printed surgical template

Autotransplantation is a treatment option with high reported survival rates to replace failing teeth in the anterior maxilla. This treatment requires a multidisciplinary approach from orthodontists, paediatric dentists, restorative dentists, and oral and maxillofacial surgeons to achieve successful outcomes. Success is dependent on many factors including stage of root development, handling of the periodontal ligament, extra-alveolar time and splinting. This case report presents the novel use of digitally designed and three-dimensional (3D) printed surgical templates to aid intraoperatively and reduce the extra-alveolar time. A preoperative cone-beam computed tomography scan allowed digital planning and construction of surgical templates that replicated the exact root dimensions of impacted maxillary canines. These templates were subsequently 3D printed in resin, sterilised and utilised intraoperatively to aid socket preparation before the surgical autotransplantation.

Use of CBCT Guidance for Tooth Autotransplantation in Children

Tooth autotransplantation (TAT) offers a viable biological approach to tooth replacement in children and adolescents. The aim of this study was to evaluate the outcome of the cone-beam computed tomographic (CBCT)–guided TAT compared to the conventional TAT protocol and to assess the 3-dimensional (3D) patterns of healing after CBCT-guided TAT (secondary aim). This study included 100 autotransplanted teeth in 88 patients. Each experimental group consisted of 50 transplants in 44 patients (31 males and 19 females). The mean (SD) age at the time of surgery was 10.7 (1.1) y for the CBCT-guided group. This was 10.6 (1.3) y for the conventional group. The mean (SD) follow-up period was 4.5 (3.1) y (range, 1.1 to 10.4 y). Overall survival rate for the CBCT-guided TAT was 92% with a success rate of 86% compared to an 84% survival rate and a 78% success rate for the conventional group ( P > 0.005). The following measurements were extracted from the 3D analysis: root hard tissue volume (RV), root length (RL), apical foramen area (AFA), and mean and maximum dentin wall thickness (DWT). Overall, the mean (SD) percentage of tissue change was as follows: RV gain by 65.8% (34.6%), RL gain by 37.3% (31.5%), AFA reduction by 91.1% (14.9%), mean DWT increase by 107.9% (67.7%), and maximum DWT increase by 26.5% (40.1%). Principal component analysis (PCA) identified the mean DWT, RV, and maximum DWT as the parameters best describing the tissue change after TAT. Cluster analysis applied to the variables chosen by the PCA classified the CBCT group into 4 distinct clusters (C1 = 37.2%, C2 = 17.1%, C3 = 28.6%, C4 = 17.1%), revealing different patterns of tissue healing after TAT. The CBCT-guided approach increased the predictability of the treatment. The 3D analysis provided insights into the patterns of healing. CBCT-guided TAT could be adopted as an alternative for the conventional approach. (Clinical trial center and ethical board University Hospitals, KU Leuven: S55287; ClinicalTrials.gov Identifier: NCT02464202)