Clinical study on prognostic factors for autotransplantation of teeth with complete root formation

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.

Midterm outcomes of autogenous mature third molars transplantation into surgically created sockets: A retrospective cohort study

BACKGROUND/AIMS

The purpose of this study was to observe the outcome of mature third molars transplantation into surgically created sockets with the assistance of computer designed three dimensional (3-D) printed replicas and compare its outcome with the conventional fresh socket autotransplantation.

MATERIAL AND METHODS

This study included total of 96 mature third molars autotransplanted in 96 cases with the guidance of computer designed 3-D printed replicas. Forty-eight teeth autotransplanted into surgically created sockets were enrolled into the surgically created socket group and 48 teeth conventionally autotransplanted into fresh sockets were enrolled into the fresh socket group. In the surgically created socket group, mature third molars were autotransplanted into surgically prepared sockets at the site of previously missed or extracted molars in the alveolar bone and in the fresh socket group, autotransplantation of mature third molars were performed in fresh sockets of extracted diseased molars simultaneously. After transplantation, the visual analogue scale (VAS) score, Landry Wound Healing Index (LWHI), mobility and probing depth (PD) of the transplanted teeth were measured and the patient satisfaction questionnaire were held in both group. All patients underwent clinical and radiographic examinations during the follow-up.

RESULTS

During the mean follow-up period of 47.63 ± 16.78 months (range 18-78 months), 92 out of 96 teeth remained in situ without clinical or radiographic complications with overall success rate of 95.83%. No statistically significant differences were found in success and survival rates between the two group. The average extra-oral time of the donor teeth were 60.76 ± 22.41 s and mean positioning trials of the donor teeth were 2.43 ± 1.19. The VAS score at Day 1 in the surgically created socket group was higher than the fresh socket group (p < .05). LWHI scores in the surgically created group were lower than the fresh socket group during the first 2 weeks (p < .05). The degree of mobility of the transplanted teeth in both group showed no statistically significant difference during the first 3 months. PD in the surgically created group were higher than the fresh socket group in the first month but there were no statistically significant difference after 1 month. Twenty-six out of 48 cases in the surgically created group needed crown restoration while only 10 cases went through crown restoration in the fresh socket group. Most patients in both group were satisfied with the treatment.

CONCLUSIONS

Autogenous mature third molars transplantation into surgically created sockets is as effective as conventional fresh socket transplantation. This technique is worth recommending in carefully selected cases and optimistic results can be achieved.

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.

Autogenic Molar Transplantation of Third Molar with Complete Root Formation Versus Incomplete Root Formation: A Prospective Clinical Study

Introduction

The aim of the study was to assess and compare the efficacy of autotransplantation of molars with complete and incomplete root formation, by checking the viability of the procedure to replace non-restorable molar teeth in the extraction sockets.

Materials and Methods

Twenty patients with non-restorable molars were included in this study. They were divided into two groups with complete and incomplete root-formed third molars, which needed to be transplanted in place of non-restorable molars. A routine surgical procedure was performed to remove infected molars. Atraumatic removal of the third molar was performed and reimplanted in the socket of previously extracted infected molars.

Results

Results were evaluated based on clinical observation and radiographic analysis of the transplanted tooth. Out of 20 transplants, one transplant, despite good initial stability, was extracted after one month because of abnormal horizontal and axial mobility; this was the single failure case (5%). Of the rest, 19/20 (95%) transplants were followed up for 6 months and showed no failure.

Conclusion

This study clearly indicated that the benefits of autotransplantation over other treatment options are numerous, and the results are not affected by whether the root of the transplanted tooth is complete or incompletely formed.

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.

Validation of a Cox prognostic model for tooth autotransplantation

OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Clinical Assessment of Immediate Autotransplantation of Mandibular Third Molars: An In Vivo Study

INTRODUCTION

Transplanting a tooth from one area of the mouth to another is known as autogenous tooth transplantation. It is a great choice for restoring young patients' teeth with developing alveolar bone because it uses the patient's own tooth as the replacement rather than a false one. This study aims to evaluate pain, infection, mobility, resorption, ankylosis, and success rate in the replacement of mandibular non-restorable molars through an immediate autotransplantation of the nonfunctional impacted mandibular third molar.

MATERIALS AND METHODS

In this in vivo study, 20 patients between the ages of 22 and 50 were selected. The cases in which the first or second mandibular molar was nonrestorable and had an impacted third molar for transplantation were selected. In all the cases, the nonrestorable molar was extracted and replaced with a nonfunctional, impacted third molar. All the cases were evaluated for pain, infection, mobility, ankylosis, and resorption at the postoperative second week, one month, third month, and six months. The pain was assessed on the visual analog scale (VAS), infection was assessed by the presence of purulent discharges, mobility was assessed on a clinical examination of tooth movements, ankylosis was seen radiographically as the obliteration of the periodontal ligament space, and the absence of the lamina dura and resorption were seen radiographically as radiolucency on the root surface. All the readings were tabulated and statistically analyzed.

RESULTS

Pain was seen to be maximal at two weeks and minimum at six months. Infection was not seen at all time intervals. Mobility was reduced with time. There was no significant ankylosis or resorption. Out of the 20 cases, four patients required extractions due to resorption and grade 3 mobility. One patient showed ankylosis. The success rate of the autotransplantation was 75%. Fifteen patients showed well-defined lamina dura without ankylosis or resorption.

CONCLUSION

Autotransplantation is a valuable tooth replacement option and more economical, especially when provided with proper case selection.

Autotransplantation of Maxillary Third Molar with Its Attached Buccal Cortical Plate Combined with a Connective Tissue Graft

INTRODUCTION

Tooth replacement often leads to insufficient vertical volume in the recipient socket bone. The aim of this novel report is to present a successful fully guided autotransplantation of a maxillary right third molar (tooth #1) with its attached buccal plate. The procedure was combined with a palatal connective tissue graft to reconstruct a buccal hard and soft tissue defect of an irreparable maxillary right first molar (tooth #3).

METHODS

A 45-year-old man complaining of pain in tooth #3 came to the clinic. Tooth #3 was non-restorable due to an extensive caries and a vertical root fracture of the mesiobuccal root, leading to a total loss of the buccal cortical plate. Guided autotransplantation of tooth #1 was completed by using 3-dimensional surgical templates for implant burs and a 3-dimensional-printed replica. After positioning the donor tooth, the cortical plate was fixed to the recipient socket with osteosynthesis screws. A connective tissue graft was also harvested to increase the band of keratinized gingiva and the thickness of the buccal soft tissue. At 6-month follow-up, the screws were removed, showing excellent regeneration throughout the buccal area.

RESULTS

At 3-year follow-up, the transplanted tooth was asymptomatic, with a natural bone level and no signs of replacement or inflammatory root resorption.

CONCLUSIONS

The use of a donor tooth and its attached bone cortical plate combined simultaneously with a connective tissue graft appears to improve hard and soft tissues in a single procedure.

Long-Term Survival Rate of Autogenous Tooth Transplantation: Up to 162 Months

Background and Objectives: The purpose of this study is to observe the usefulness of autogenous tooth transplantation by examining the cumulative survival rate according to the period of auto-transplanted teeth as pre-implant treatment. Materials and Methods: This study was conducted on 111 patients who visited Kyungpook National University Dental Hospital and underwent autogenous tooth transplantation between November 2008 and January 2021 (about 13 years). The cumulative survival rate of autogenous tooth transplantation according to the causes of extraction of the recipient tooth (caries, periapical lesion, crack, crown fracture, periodontitis) and condition of opposing teeth (natural teeth vs. fixed prosthesis). The cumulative survival rate of autogenous tooth transplantation according to the age (under 30 vs. over 30) was also investigated and it was examined whether there were any differences in each factor. Results: The average follow-up period was 12 months, followed by a maximum of 162 months. The 24-month cumulative survival rate of all auto-transplanted teeth was 91.7%, 83.1% at 60 months and the 162-month cumulative survival rate was 30.1%. There were no statistical differences between the causes of extraction of the recipient's teeth, differences in the condition of the opposing teeth, and differences under and over the age of 30. Conclusions: The survival rate of autogenous tooth transplantation appears to be influenced by the conditions of the donor tooth rather than the conditions of the recipient tooth. Although autogenous tooth transplantation cannot completely replace implant treatment, it is meaningful in that it can slightly delay or at least earn the time until implant placement is possible.

Tooth auto-transplantation to close an oro-sinusal communication using a 3D printed model to adapt the alveolar socket: a case report

Introduction: Tooth auto-transplantation has a high success rate therapy when limiting the extra-oral time of the graft. In this way, printing a 3D model of the germ can be a useful tool in order to prepare the receiving site. Observation: We treated a case of post extractional oro-sinusal communication closure using a 3D pattern to adapt the alveolar socket receiving the wisdom tooth auto-transplantation. Comment: Extra-oral time spent by the graft was under 15 seconds improving the chance of success. After one year follow up, the graft is vital, functional and it continued its root formation. Conclusion: 3D printing seems to be an effective technique to minimize surgical time leading to a higher rate of success for auto-transplantation therapies.

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.

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.

Surgical Management of Impacted Lower Second Molars: A Comprehensive Review

Impacted lower second molars (ILM2) are rarely reported in the literature, but various studies have been done for its treatment. Apart from solely orthodontic approaches, different surgical management techniques were reported to have successful outcomes. Surgical intervention of ILM2 can help expose the tooth for further orthodontic purposes, simplifying complex treatment methods, and reducing treatment time. This review illustrates the comprehensive evaluation and updated methods of surgical uprighting, repositioning, and transplantation of ILM2 with future directions for better understanding and treatment planning in the clinical setting. The successful outcome of surgical intervention depends on case selection, root development of ILM2, careful surgical manipulation, and adherence to sound biological principles.

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.

Long-Term Outcome of Autotransplantation of a Complete Root Formed a Mandibular Third Molar

Autogenous tooth transplantation is a procedure to reposition an autogenous tooth to another extraction area or surgically created recipient site. The autotransplantation procedures have been documented well in the literature, and the survival rate of the transplanted teeth was reported to be more than 90% after ten years. Therefore, autotransplantation might have been overlooked as a treatment option. The purpose of this case report is to evaluate the long-term (29-year) success and periodontal stability of the tooth autotransplantation from the mandibular third molar to the second molar. A 24-year old female presented to a clinic with a large caries lesion with periapical radiolucnecy on to tooth #18. The tooth was extracted with the site and treated with autogenous tooth transplantation from #17 with a complete root form. Endodontic treatment was completed 3 months post autotransplantation; the final prosthesis was placed 6 months postoperatively. The patient has shown excellent oral hygiene care and high compliance with the regular maintenance recall program. The transplanted tooth has been still functioning without any symptoms. Radiographic and clinical examinations revealed stable periodontal and endodontic conditions over the 29 years after the procedure. This case report showed the long-term success of autotransplantation of the mandibular third molar with a closed root apex to the second molar site. Autotransplantation can be an option when an adequate donor site is available to reconstruct the occlusion after the tooth extraction.

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.

Orthodontic treatment of a skeletal Class III malocclusion with severe root resorption of the maxillary anterior teeth. Autotransplantation using a 3-dimensional printed replica of the donor tooth

This case report describes the successful orthodontic treatment of a 12-year-old girl with skeletal Class III malocclusion and severe root resorption of the maxillary anterior teeth. Ectopic eruption and mesial inclination of the bilateral maxillary canines caused severe root resorption of the right central and lateral incisors and the left lateral incisor. These 3 teeth were extracted, and traction was applied to the maxillary right and left canines toward the extracted right central incisor and left lateral incisor, respectively. In the mandibular arch, the bilateral first premolars were extracted, and the crowding was corrected. The extracted mandibular right first premolar was transplanted after extraction of the maxillary right lateral incisor. To prepare for the tooth transplantation, a cone-beam computed tomography image was used to fabricate a 3-dimensional printed replica of the donor tooth. The crown shape of the maxillary anterior teeth was corrected, and the patient achieved functional occlusion with pleasing esthetics. Root resorption was negligible in the transplanted tooth. This study demonstrates the satisfactory treatment outcome and an effective 3-dimensional simulation for tooth transplantation.

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.

Autotransplantation of the Third Molar: A Therapeutic Alternative to the Rehabilitation of a Missing Tooth: A Scoping Review

INTRODUCTION

Tooth autotransplantation is the repositioning of an erupted, partially erupted, or non-erupted autologous tooth from one site to another within the same individual. Several factors influence the success rate of the autotransplant, such as the stage of root development, the morphology of the tooth, the surgical procedure selected, the extraoral time, the shape of the recipient socket, the vascularity of the recipient bed, and the vitality of the cells of the periodontal ligament. The aim of this scoping review was to provide the most up-to-date information and data on the clinical principles of the third-molar autograft and thus provide clinical considerations for its success.

MATERIALS AND METHODS

This review was conducted based on PRISMA-ScR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews). The research was conducted by searching for keywords in three databases-PubMed, Scopus and Google Scholar-by two independent reviewers following the PRISMA protocol, from which 599 records were identified.

CONCLUSIONS

Third-molar autotransplantation is a valid solution to replace missing teeth. The key to the success of this technique is the surgical procedure, which must be as atraumatic as possible to preserve the periodontal ligament of the tooth to be transplanted. The success rate is also linked to the stage of development of the root, with a worse prognosis in the case of a complete root.

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.

Mesioangulation of mandibular second molars: A case report

This case report describes a simple alternative for treatment of mesioangulation of mandibular second molars. An 11-year-old girl was diagnosed with unilateral posterior crossbite, moderate incisor crowding and mesioangulation of the right mandibular second molar. The ectopic second molar was uprighted using a modified lingual arch with a distal hook and elastic chains. Orthodontic traction began after appliance installation and was activated once per month using 120 g of force. After six months, the right mandibular second molar was in an upright position. Orthodontic treatment continued with teeth levelling and alignment until acceptable occlusal and aesthetic results were achieved. Adequate stability was observed one year after debonding. The modified mandibular lingual arch with a distal hook is a simple and effective alternative to manage mesioangulation of mandibular second molars with minimum adverse effects and stable outcomes.

Guided tooth autotransplantation in edentulous areas post-orthodontic treatment

OBJECTIVE

Tooth autotransplantation with a complete root formation to replace one or more lost teeth is indicated as a cost-effective alternative to implants. The aim of this case report was to describe a successfully guided autotransplantation of a maxillary third molar with fully formed roots into a surgically created socket after orthodontic space opening.

CLINICAL CONSIDERATIONS

A guided autotransplantation of the maxillary left third molar into the missing maxillary left first molar site was chosen. After virtually orientating donor tooth to confirm its optimum fit, it was deemed necessary to open 4 mm the mesiodistal space. Following the orthodontic movement, a 3-dimensional (3D)-guiding template and a milled surgical guide were manufactured to allow the donor tooth to be transplanted exactly in the planned position. The 2-year follow-up periapical radiograph showed a continuous periodontal space with no signs of apical periodontitis or root resorption.

CONCLUSIONS

Virtual planning and 3D-printed tooth replica combined with guided surgery can simplify the autotransplantation technique for both the clinician and the patient, particularly when the socket has been completely created during surgery.

CLINICAL SIGNIFICANCE

Virtual digital planning, which can accurately calculate the exact space to open orthodontically before an autotransplantation, could prove essential to enhancing the precision of 3D placement of the donor tooth in the recipient site.

Autotransplantation of a completely developed impacted maxillary canine: A 7-year follow-up case report

BACKGROUND

Impacted maxillary canines are likely to be extracted in adult patients once orthodontic treatment is ruled out. The missing teeth are generally replaced with dental implants.

CASE DESCRIPTION

The authors report the clinical case of a 45-year-old man who was missing the maxillary left canine for 30 years. Radiographic examination revealed that the maxillary permanent left canine was palatally impacted. The tooth was transplanted into the prepared socket on the missing tooth site and secured in the desired position with a flexible wire splint. During the 7-year follow-up, the tooth remained clinically sound with no radiographic manifestation of inflammatory or root resorption.

PRACTICAL IMPLICATIONS

The prognosis for the transplanted tooth was favorable after long-term follow-up observation. This result suggests that autotransplantation of impacted maxillary canines can be a viable treatment option for some adult patients who expect to retain their natural teeth.

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.

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.

Third molar autotransplant planning with a tooth replica. A year of follow-up case report

The advantages of dental autotransplantation and its high level of clinical success mean that it should be considered as a therapeutic option when replacing a lost tooth. In order to achieve optimum results, it is necessary to know the technique of dental autotransplantation, promoting its use whenever the clinical conditions to perform it are present. The objective of this article is to describe the technique in detail by means of a clinical case of a dental autotransplant whose donor tooth was a third unerupted molar. A 39-year-old male patient with no medical history of interest. On clinical examination, tooth 2.6 shows vertical fracture with indication of exodontia. A compatibility study is carried out using a CBCT and after this, a subsequent preparation of a 3D-printed replica of the donor tooth 2.8 is made. A step-by-step description is given of the autotransplantation technique from 2.8 to 2.6. After this, antibiotic coverage, semi-rigid splinting and root canal treatment are carried out in a short time. Results are shown at 12 months. The main factor for the success of this technique is the preservation of periodontal ligament cells. The unerupted teeth are the only ones that fully preserve the periodontal ligament, but they require greater surgical skills. Autotransplantation is a predictable treatment alternative to dental implants, being above all an option indicated to replace teeth with dental fissures or vertical root fractures or poor restorative and/or endodontic prognosis. The third molars are the most used teeth for transplantation, due to their indications for extraction in a high percentage preserving the entire periodontal ligament. The diagnosis by CBCT and the use of 3D- printed replicas of the tooth to be transplanted have meant a highly significant improvement in the prognosis and predictability of the technique. Key words:Dental autotransplant, tooth replica, third molar.

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.

Autotransplantation of teeth as an alternative to dental implantation

Autotransplantation of teeth is a considerable option for tooth replacement in adults who are to undergo orthodontic treatment. Being compared with dental implantation, this procedure is more preferable as a grafted tooth functions as a normal one. In this case report, we describe successful autotransplantation of the third molar with complete root formation. To provide better adaptation of the donor tooth, we used its preoperatively printed replica. The donor tooth was immediately placed to the recipient site and splinted for 28 days. Endodontic treatment was initiated 2 weeks after transplantation. Clinical and radiographic findings at 6 and 12 months of follow-up are compared with the results described in the literature.

Periodontal ligament proliferation and expressions of bone biomolecules upon orthodontic preloading: Clinical implications for tooth autotransplantation

Objective

Preservation of the periodontal ligament (PDL) is vital to the success of tooth autotransplantation (TAT). Increased PDL volumes and facilitated tooth extraction have been observed upon orthodontic preloading. However, it is unclear whether any changes occur in the expressions of bone biomolecules in the increased PDL volumes. This study aimed to determine the expressions of runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), receptor activator of nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG) in PDL upon preloading.

Methods

Seventy-two premolars from 18 patients were randomly assigned to experimental groups that received a leveling force for 1, 2, or 4 weeks or to a control unloaded group. Following extraction, PDL volumes from 32 premolars of eight patients (21.0 ± 3.8 years) were evaluated using toluidine blue staining. The expressions of the biomolecules in the PDL from 40 premolars of ten patients (21.4 ± 4.0 years) were analyzed via immunoblotting.

Results

The median percentage of stained PDL was significantly higher at 2 and 4 weeks after preloading than in the unloaded condition (p < 0.05). The median RUNX2 and ALP expression levels were significantly higher at 2 and 4 weeks after preloading than in the unloaded condition (p < 0.05), whereas the median RANKL/OPG ratios were significantly higher at 1 and 4 weeks after preloading (p < 0.05).

Conclusions

Orthodontic preloading for 4 weeks enhances PDL volumes as well as the expressions of RUNX2, ALP and the RANKL/OPG ratio in the PDL, suggesting this loading period is suitable for successful TAT.

Autotransplantation of third molars with completely formed roots to replace compromised molars with the computer-aided rapid prototyping

OBJECTIVE

To describe a method to fabricate donor tooth replica to assist surgeons in preparation of recipient socket during tooth autotransplantation.

MATERIALS AND METHODS

A total of 28 compromised molars in 27 patients were transplanted with third molars using computer-aided rapid prototyping (CARP) technique. Surgery time and extra-alveolar time were documented. Postoperatively, the distance between cervix of transplanted tooth and the alveolar wall was measured. The degree of postoperative pain experienced was assessed with visual analog scale at day 1, 3, and 7.

RESULTS

From 28 clinical cases, the average extra-alveolar time and surgery time were 2.5 minutes (±1.3) and 44 minutes (±6.8), respectively. Postoperatively, the average distance between cervix of transplanted tooth and the alveolar wall was 0.87 mm (±0.15) at the mesial-cervix, 0.95 mm (±0.17) at the distal-cervix, 0.88 mm (±0.18) at the buccal-cervix, and 0.95 mm (±0.13) at the lingual-cervix. The value of visual analog scale score significantly decreased from day 1 to day 3.

CONCLUSIONS

CARP is a reliable technique for fabrication of tooth like surgical replicas in conventional autotransplantation.

CLINICAL SIGNIFICANCE

CARP technique minimized extra-oral time, reduced iatrogenic damage, and consequently increased the survival rate of tooth autotransplantation.

Endodontic considerations of survival rate for autotransplanted third molars: a nationwide population-based study

AIM

To investigate whether the timing of root canal treatment (primary aim) or other endodontic parameters (secondary aim) is associated with the survival probability of autotransplanted third molars, using a nationwide population-based database.

METHODOLOGY

A total of 1811 third molars autotransplanted between 2000 and 2013 met the inclusion criteria and were followed until the end of 2016. The teeth were classified into three groups on the basis of timing between root canal treatment and the autotransplantation: preoperative, extraoral and postoperative treatment groups. Univariate and multivariate Cox proportional hazards models were used to estimate the association between the timing of root canal treatment and the risk of tooth extraction after autotransplantation.

RESULTS

Of the 1811 autotransplanted third molars, 462 were extracted, yielding a 17-year survival probability of 0.578. The survival probability of autotransplanted teeth that received postoperative root fillings after 17 years was 0.583, which was significantly higher than the 0.434 and 0.566 for teeth that received preoperative and extraoral root fillings, respectively (P = 0.0013). After adjustment for potential confounding factors, teeth that received postoperative root fillings were associated with a significantly lower tooth extraction hazard ratio (HR) compared with those that received extraoral root fillings (adjusted HR, 1.43; 95% confidence interval [CI], 1.14-1.78) and those that received preoperative root fillings (adjusted HR, 2.13; 95% CI, 1.19-3.82). Furthermore, the use of a rubber dam during postoperative root filling was associated with a significantly lower extraction rate after autotransplantation (adjusted HR, 0.54; 95% CI, 0.43-0.69).

CONCLUSIONS

Postoperative root canal treatment resulted in a significantly lower extraction rate than did preoperative or extraoral root canal treatment amongst autotransplanted third molars during a mean follow-up period of 8.33 years. Rubber dam use is recommended during postoperative root canal treatment to improve the outcomes of autotransplantation.

Autotransplantation of mature impacted tooth to a fresh molar socket using a 3D replica and guided bone regeneration: two years retrospective case series

Background

The aim of this study was to evaluate the clinical outcome of autotransplantation of mature third molars to fresh molar extraction sockets using 3D replicas.

Methods

Ten patients underwent teeth autotransplantation with or without GBR. We observed the mobility, percussion, radiography examination, the probing depth and the masticatory function of the transplanted teeth during 2 years following up, which were transplanted into fresh molar sockets by using 3D replicas, and GBR when it is necessary.

Results

The average extra-oral time of donor tooth had been shortened to 1.65 min when used the 3D replica. Some probing depth of the transplanted tooth were deeper than 3 mm at 4 or 5 weeks temporarily. And one patient felt slight sensitive when chewing with soft food at 4 weeks, then disappeared. The clinical examination of the autotransplantation teeth during 1 year follow-up showed no sign of failure.

Conclusions

The tooth autotransplantation using 3D replica with or without GBR is an effective method which can reduce the extra-oral time of the donor teeth and may result in less failure.

Development and validation of the autotransplanted maxillary canine radiological index

The purpose of this study was to propose and validate an index evaluating 2D and 3D radiographic variables of autotransplanted maxillary canines. Setting and sample population are from the Department of Oral and Maxillofacial Surgery at University Hospitals Leuven. Eight oral-maxillofacial surgeons rated 12 autotransplanted maxillary canines and adjacent bone using 11 rating variables. A new autotransplanted maxillary canine radiological index (AMCRI) was proposed. It consisted of 11 variables. These variables were based on 2D (intraoral) and 3D Cone Beam Computed Tomography (CBCT) radiographs. Intraclass correlation coefficient (ICC) and Fleiss's kappa statistics were performed to analyze intrarater and interrater agreement. Considering cumulative assessment of the AMCRI, the mean ICC value for the interrater agreement of the eight examiners was 0.94, representing an excellent agreement. Intrarater agreement was 0.91. The AMCRI is an objective tool in rating radiological outcome of autotransplanted canines and adjacent bone, when compared with the contralateral canine.

Outcome of Autotransplantation of Mature Third Molars Using 3-dimensional-printed Guiding Templates and Donor Tooth Replicas

Autotransplantation exhibits a number of advantages compared with other treatment options (ie, dental implants or fixed partial prostheses), such as greater resistance to occlusal loading, maintenance of the periodontal ligament and surrounding bone, and the potential for better esthetics. The aim of this study was to determine clinical outcomes for autotransplanted teeth with complete root formation using 3-dimensional-printed guiding templates and tooth replicas. Twenty-seven third molars with completely formed roots were autotransplanted. Each donor tooth and recipient site were examined clinically and radiographically (periapical radiographs). A selective cone-beam computed tomographic scan was taken of each donor tooth and recipient site. The images of the selected donor teeth were segmented and saved as stereolithography files. Similar to virtual planning of dental implants, correct angulation, rotation, and accurate positioning of the donor teeth were predefined using the stereolithography files. According to the virtually defined positions and dimensions of the donor teeth, 3-dimensional guiding templates and donor tooth replicas were printed. All autotransplantations were performed according to 1 treatment protocol and surgical technique. In 22 of the 24 transplanted teeth, no inflammation occurred during the healing period. At 2 years, no pathologic radiolucency or tooth resorption was observed in the 22 donor teeth. The autotransplanted teeth fulfilled the success criteria in 22 cases for a 91.7% success rate. Digital planning could potentially provide an accurate alternative to current autotransplantation techniques.

Influence of Extraoral Apicoectomy on Revascularization of an Autotransplanted Tooth: A Case Report

Autotransplantation is considered a standard procedure with a poorer prognosis for mature than for immature teeth. In this case report, the root tip of an almost fully developed tooth was resected during autotransplantation to fit into a deficient recipient site. As a positive side effect, the apical foramen was enlarged, with potential improvement of the probability of revascularization. Clinical and radiologic follow-up examinations up to 18 months indicated revascularization and uneventful periodontal regeneration and thus successful autotransplantation. This case supports the hypothesis that intraoperative apicoectomy can improve the prognosis for revascularization of mature autotransplanted teeth. Further prospective controlled clinical studies are needed to confirm this innovative surgical approach.

A preliminary study of effects of low-intensity pulsed ultrasound (LIPUS) irradiation on dentoalveolar ankylosis

The purpose of this experiment was to investigate whether low-intensity pulsed ultrasound (LIPUS) irradiation can inhibit dentoalveolar ankylosis in transplanted rat teeth. LIPUS irradiation (the pulsed ultrasound signal had a frequency of 3.0 MHz, a spatial average intensity of 30 mW/cm², and a pulse ratio of 1:4) was performed on the face over the re-planted teeth of rats for 4 weeks. After the rats were euthanized, we measured mobility (Periotest value [PTV]) of the transplanted and control teeth using a Periotest. Finally, we performed histological evaluation to detect ankylosis. PTVs tended to be significantly lower for re-planted teeth than for control teeth. Histological evaluation revealed that the roots of all re-planted teeth were coalescent with alveolar bone. Furthermore, no ankylosis was observed in three-fifths of the re-planted teeth following LIPUS irradiation. These results indicate the potential efficacy of LIPUS to inhibit dentoalveolar ankylosis.

Autotransplantation of mature and immature third molars in 23 Chinese patients: a clinical and radiological follow-up study

BACKGROUND

We investigated the clinical and radiographic outcomes of autotransplanted teeth over a follow-up period of 2 to 8 years, and summarize the findings of other relevant studies with regard to the primary factors that influence a good prognosis in such patients.

METHODS

Twenty-three patients (6 men, 17 women) who attended Tanggu Stomatological Hospital, Tianjin, China, from 2008 through 2013, were included in the study. These patients presented with a variety of dental problems, including tooth loss, residual crowns, missing first or second molars, dental trauma, tooth fracture, and unrestored teeth. A total of 26 third molars, including 2 immature molars, were autotransplanted in these patients. The success rate of autotransplantation was assessed on the basis of clinical and radiographic outcomes after follow-up periods ranging from 2 to 8 years.

RESULTS

Clinical examination revealed stability of all 26 transplanted teeth, with satisfactory masticatory function and no patient discomfort. Radiographic examination revealed normal periapical tissues and an intact lamina dura surrounding the tooth root, indicating adequate healing of periodontal tissues.

CONCLUSIONS

Autotransplantation achieved good results in the Chinese sample population investigated, and was associated with an excellent prognosis. Rigorous case selection, adequate protection of the periodontal ligament, and proper oral hygiene contribute significantly to the long-term success of the procedure.

Eight-year follow-up of autogenous tooth transplantation involving multidisciplinary treatment

Although autogenous tooth transplantation is a widely reported procedure, its success is dependent on a number of factors. Here we describe the surgical technique, endodontic treatment and rehabilitation employed for a patient in whom a lower right third molar was transplanted to substitute an adjacent second molar with extensive caries. During an 8-year follow-up period, normal periodontal healing was observed and no infection, ankylosis or progressive resorption occurred. It may be concluded that transplantation of a third molar is a practicable approach for replacement of a lost permanent tooth, with restoration of esthetics and function.

Tooth Auto-transplantation: An Alternative Treatment

Auto-transplantation is the repositioning of an autogenously erupted, partially erupted, or unerupted tooth from one site to another in the same individual. The purpose of this case report is to describe the auto-transplantation of the mandibular third molars as an alternative means of replacing second molars requiring extraction. An orthopantomogram revealed horizontal impaction of teeth #37 and 47 and mesio-angular impaction of teeth #38 and 48. Cone beam computed tomography revealed that the roots of #37 and 47 were in close proximity to the inferior alveolar canal bilaterally. As atraumatic and complete removal of these two teeth was not possible, #38 and 48 were chosen as the donor teeth instead. The procedure was carried out under general anesthesia. Teeth #38 and 48 were extracted atraumatically; teeth #37 and 47 were pulled out by sectioning and transplant sites prepared. Teeth #38 and 48 were transplanted to the sites vacated by teeth #37 and 47, respectively. Endodontic treatment of teeth #38 and 48 was completed within 1 month following transplantation. Both clinical and radiographic outcomes were considered satisfactory at 1 year postoperatively. Bone healing was observed around the roots of teeth #38 and 48. In conclusion, although auto-transplantation is not very common in general dental practice, we believe that it offers a clinically and economically viable alternative to other complicated prosthetic and dental implant treatments.

Posterior Open Bite Due to Failure of Maxillary Molar Eruption

Posterior open bite can cause problems with occlusion. It arises from systemic or local factors such as physical or functional interference, ankylosis, and failure of eruption. Primary failure of eruption (PFE) is a rare condition that is difficult to differentiate from ankylosis and requires complex treatment strategies. Here we report a 12-year-old girl who was referred to our hospital by her dentist for re-evaluation of eruption failure of the left maxillary secondary premolar and first and second molars with congenitally missing maxillary lateral teeth. The maxillary first molar was extracted for a therapeutic diagnosis. The left maxillary secondary premolar and second molar reacted well to subsequent orthodontic treatment. Auto-transplantation of the mandibular premolar to the maxil-lary arch was carried out to achieve optimal overjet, overbite, and occlusion. The active treatment period spanned 4 years and 1 month. Assessment of the patient's medical and dental history, prior trauma, and clinical conditions resulted in a therapeutic diagnosis of PFE. Satisfactory orthodontic treatment results were achieved.