Autotransplantation of immature third molars into edentulous and atrophied jaw sections

Combined application of artificial bone powders and concentrated growth factor membranes on the autotransplantation of mature third molars: A 5-year retrospective case series

AIM

This study aimed to observe the efficacy and outcomes of the combined application of artificial bone powder and concentrated growth factor (CGF) membranes for tooth transplantation in cases with wide recipient sockets and small donor teeth.

MATERIAL AND METHODS

A total of 36 teeth from 36 patients with wide recipient sockets and small donor teeth were enrolled. Autogenous tooth transplantation was performed using bone powders and CGF membranes. After transplantation, the visual analog scale (VAS) score, Landry Wound Healing Index, probing depth (PD), mobility, and gray value of the alveolar bone around the transplanted teeth were measured, and a patient satisfaction questionnaire was administered. All patients underwent clinical and radiographic examinations during follow-up.

RESULTS

The VAS score of 16 (44.4%) cases after 1 week was 0, and 26 (72.2%) patients showed excellent gingival healing after 2-4 weeks. The PD of a few cases was deeper than 3 mm during the first month; however, returned to normal after 3 months. Although the majority of the transplanted teeth possessed mobility greater than grade I during the first month, the mobility gradually improved within 3 months. The gray value of the alveolar bone around the transplanted teeth, 1 year postoperatively showed no difference with pre-operation (p > .05). During the mean follow-up period of 42.7 months (range 20-72 months), 33 of the 36 transplanted teeth remained in situ without clinical or radiographic complications, with an overall success rate of 91.7%.

CONCLUSIONS

Although the PD and mobility of the transplanted teeth were not ideal during the early stages of healing, most of the transplanted teeth had good clinical outcomes. In cases with large recipient sites accompanied by small donor teeth, autotransplantation of teeth using artificial bone powder combined with CGF membranes is a viable option and can lead to optimistic results with favorable success rates.

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.

Evaluation of the 3D Technology in the Auto-transplantation: An Original Research

Introduction

Using three-dimensional printed duplicates of the donor teeth, three-dimensional auto-transplantation is a medical procedure that moves a tooth from one location inside a patient to another. The intraoperative practicability during 3D auto-transplantation of teeth was evaluated in the present study.

Material and Methods

A prospective multicenter clinical study was done among the subjects. "Preoperative cone-beam computed tomography imaging," "computer-assisted design (CAD)," and "computer-assisted manufacturing (CAM)" were used in all operations to make a 3D duplicate of the donor teeth. The clinical parameters that were evaluated were the time required for the fit, number of attempts to fit, and intra-operative experience.

Results

Canines, premolars, molars, and one extra tooth were all transplanted during the 200 auto-transplantation surgeries among 152 subjects. An initial satisfactory fit of the donor tooth and an extra-alveolar time of less than one minute were achieved in 80% of the surgeries. The extra-alveolar time exceeded 3 minutes in ten teeth. Difficulties that were faced were related to the imaging, patient cooperation, and the bone quality.

Conclusions

The application of the duplicate teeth by 3D printing of a donor tooth all through auto-transplantation techniques reduced the time the tooth stays extra-alveolar as well as the efforts at transplant fitting during implantation. This allowed for more challenging surgeries as well as a speedy and reliable therapy.

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.

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.

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.

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.

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.

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.

Pre-autotransplantation alveolar process augmentation and premolar autotransplantation as a treatment method for single tooth replacement in adolescents

The treatment of young patients with missing teeth and an atrophied alveolar process after trauma or agenesis of a tooth can be challenging. The aim of this study was to evaluate autotransplantation of a premolar after pre-autotransplantation alveolar process augmentation (PAPA) as a treatment option for these patients. A retrospective cohort study was implemented to analyse the PAPA procedure and subsequent autotransplantation procedure. Alveolar process augmentation was performed using different types of autologous bone grafts. Subsequent autotransplantation of one or more premolars was performed approximately 4 months later. Nine patients with a mean age of 12 years were included. Twelve premolars were transplanted after a PAPA procedure: seven in the maxillary incisor region, four in the mandibular premolar region, and one in the mandibular incisor region. Initially all transplanted teeth functioned well. However, one mandibular premolar that was transplanted in the maxillary incisor region was lost because of resorption after 6 years of follow-up. The other 11 transplanted teeth functioned well. The mean follow-up was 6 years (range 3-13 years). The results showed that autotransplantation can be facilitated by PAPA with a high chance of success. It can therefore be a valuable addition to other existing treatment options.

Application of Platelet-Rich Fibrin as Regeneration Assistant in Immediate Auototransplantation of Third Molar with Unformed Roots: Case Report and Review of Literature

Background

Autogenous Tooth Transplantation (ATT) is the surgical movement of a maturely or immaturely formed tooth from its original site to another extraction site or a surgically prepared socket in the same individual. The most important factor in the healing process after autotransplantation is the presence of intact and viable periodontal ligament cells, which have the ability to differentiate into osteoblasts and able to induce bone production. ATT can successfully replace removable dentures as a restoration option in a growing patient, while implants can be placed only after skeletal maturity is attained. Case Presentation. In this case, we presented an immediate ATT of the third molar with unformed roots to the extraction socket of the first molar with evidence of continued root formation after 2 years of follow-up.

Conclusion

Platelet-Rich Fibrin (PRF) can induce sustainable and accelerated healing, and it can also induce the regeneration process of the periodontal tissues and pulpal formation. This process plays a key role in future root development and success rate.

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.

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

BACKGROUND

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

PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Practical whole-tooth restoration utilizing autologous bioengineered tooth germ transplantation in a postnatal canine model

Whole-organ regeneration has great potential for the replacement of dysfunctional organs through the reconstruction of a fully functional bioengineered organ using three-dimensional cell manipulation in vitro. Recently, many basic studies of whole-tooth replacement using three-dimensional cell manipulation have been conducted in a mouse model. Further evidence of the practical application to human medicine is required to demonstrate tooth restoration by reconstructing bioengineered tooth germ using a postnatal large-animal model. Herein, we demonstrate functional tooth restoration through the autologous transplantation of bioengineered tooth germ in a postnatal canine model. The bioengineered tooth, which was reconstructed using permanent tooth germ cells, erupted into the jawbone after autologous transplantation and achieved physiological function equivalent to that of a natural tooth. This study represents a substantial advancement in whole-organ replacement therapy through the transplantation of bioengineered organ germ as a practical model for future clinical regenerative medicine.

Autotransplantation of third molars with completely formed roots into surgically created sockets and fresh extraction sockets: a 10-year comparative study

The aim of this study was to analyze and compare the long-term clinical outcomes of mature third molar autotransplantation in surgically created sockets and fresh extraction sockets with regard to survival and functional success rates. A total of 65 third molars with completely formed roots were autotransplanted in 60 patients (average age 33.1 years). Thirty-six of the teeth were autotransplanted into surgically created sockets with or without guided bone regeneration (GBR; delayed autotransplantation), while 29 were autotransplanted into fresh extraction sockets (immediate autotransplantation; control group). All patients underwent annual clinical and radiographic examinations (average follow-up 9.9 years, range 7-13 years). The survival rates for the control, GBR, and no GBR groups were 93.1%, 95.2%, and 80.0%, respectively, with no significant differences among the groups. There were no statistically significant differences among the groups with regard to the frequency of inflammatory root resorption or root ankylosis. Age did not influence the clinical outcomes. These results suggest that the autotransplantation of third molars with completely formed roots is effective in both surgically created and fresh extraction sockets and provides a high long-term success rate if cases are selected and treated appropriately.

Occlusal rehabilitation in patients with congenitally missing teeth-dental implants, conventional prosthetics, tooth autotransplants, and preservation of deciduous teeth-a systematic review

Background

Implant patients with congenitally missing teeth share some common charateristics and deserve special attention.

Methods

The PICO question was “In patients with congenitally missing teeth, does an early occlusal rehabilitation with dental implants in comparison to tooth autotransplants, conventional prosthetics on teeth or preservation of deciduous teeth have better general outcomes in terms of survival, success and better patient centered outcomes in terms of quality of life, self-esteem, satisfaction, chewing function?”

After electronic database search, a total of 63 relevant studies were eligible, of which 42 qualified for numerical data synthesis, 26 being retrospective studies. A data synthesis was performed by weighted means for survival/success/annual failure rates.

Results

The mean survival of implants was 95.3 % (prosthesis survival 97.8 %), autotransplants 94.4 %, deciduous teeth 89.6 %, and conventional prostheses 60.2 %. The implant survival in children, adolescents, and adults was 72.4, 93.0, and 97.4 %. Annual failure rates of implants 3.317 %, autotransplants 1.061 %, deciduous teeth 0.908 %, and conventional prostheses 5.144 % indicated better results for natural teeth and more maintenance needs for the both prosthetic treatments. The mean OHIP score was 27.8 at baseline and a mean improvement of 14.9 score points was reported after implant prosthetics. The mean satisfaction rates were 93.4 (implants), 76.6 (conventional prostheses), 72.0 (autotransplants), and 65.5 % (orthodontic space closure).

Conclusions

In synopsis of general and patient-centered outcomes, implants yielded the best results, however, not in children <13 years. Autotransplants and deciduous teeth had low annual failure rates and are appropriate treatments in children and adolescents at low costs. Conventional prosthetics had lower survival/success rates than the other options. Due to heterogeneity and low number of studies, patient-reported outcomes in this review have to be interpreted with caution.

Functional tooth restoration utilising split germs through re-regionalisation of the tooth-forming field

The tooth is an ectodermal organ that arises from a tooth germ under the regulation of reciprocal epithelial-mesenchymal interactions. Tooth morphogenesis occurs in the tooth-forming field as a result of reaction-diffusion waves of specific gene expression patterns. Here, we developed a novel mechanical ligation method for splitting tooth germs to artificially regulate the molecules that control tooth morphology. The split tooth germs successfully developed into multiple correct teeth through the re-regionalisation of the tooth-forming field, which is regulated by reaction-diffusion waves in response to mechanical force. Furthermore, split teeth erupted into the oral cavity and restored physiological tooth function, including mastication, periodontal ligament function and responsiveness to noxious stimuli. Thus, this study presents a novel tooth regenerative technology based on split tooth germs and the re-regionalisation of the tooth-forming field by artificial mechanical force.

A retrospective analysis of factors influencing the success of autotransplanted posterior teeth

Background

Survival and success rates of tooth transplantations even after long follow-up periods have been shown to be very high. Nevertheless, it is important to analyse factors potentially influencing these rates. The aim of this study was to assess the influence on success of potential factors.

Methods

The research was based on a retrospective analysis of clinical and radiological data from a sample of 59 subjects (75 transplanted teeth). The follow-up period varied from 0.44 to 12.28 years (mean 3.95 years). Success rates were calculated and depicted with Kaplan-Meier plots. Log-rank tests were used to analyse the effect of root development stage, apex width, the use of enamel matrix proteins or the surgeon on success of transplantations.

Results

Results for success of premolar transplantations were comparable with already published data, while molars performed worse than shown in other studies. The surgeon performing the transplantation (p = 0.001) and tooth type (p ≤ 0.001) were significantly associated with transplantation success. Use of enamel matrix proteins (p = 0.10), root development stage (p = 0.13), the recipient area (p = 0.48) and apex width (p = 0.59) were not significantly associated with success.

Conclusions

Molar transplantations were not as successful as premolar transplantations; however, success rates varied greatly depending on the surgeon’s experience. The use of enamel matrix proteins as well as root development stage, the recipient area and apex width did not show significant associations with success of tooth transplantations.

Autotransplantation of Immature Third Molars and Orthodontic Treatment After En Bloc Resection of Conventional Ameloblastoma

Ameloblastoma treatment can lead to significant bone defects; consequently, oral rehabilitation can be challenging. We present the case of a 14-year-old girl diagnosed with a conventional ameloblastoma in the mandible who was treated using en bloc resection and rehabilitated with autotransplantation of the immature third molars and orthodontic treatment. The lesion was in the region of the lower left canine and premolars, and en bloc resection resulted in a significant alveolar bone defect. Autotransplantation of the lower third molars to the site of the lower left premolars was performed. After 2 years, the upper left third molar was transplanted to the site of the lower left canine. During the orthodontic treatment period, considerable alveolar bone formation was observed in the region of the transplanted teeth, and roots developed. To the best of our knowledge, this is the first reported case of alveolar bone formation induction caused by tooth transplantation after ameloblastoma treatment.

Evaluating success of autotransplantation of embedded/impacted third molars harvested using piezosurgery: a pilot study

OBJECTIVE

To evaluate the success of autogenous transplantation of embedded/impacted third molars harvested using piezosurgery.

MATERIALS AND METHODS

This prospective pilot study enrolled 20 healthy patients with non-restorable first/second molars and a caries-free retrievable embedded/impacted third molar. Piezosurgery was used for removing inter-radicular bone at the recipient socket as well as for bone removal around the donor teeth.

RESULTS

After an average follow-up of 16.4 months (SD = 1.9), 18 cases were successful with formation of periodontal ligament around the teeth. One tooth was lost due to infection at 1 month. One patient was lost to follow-up. There was no root resorption or ankylosis in any of the cases. In six donor teeth with complete root formation, root canal treatment was carried out. All the remaining teeth responded positively with vitality testing.

CONCLUSION

Piezosurgery is an effective device if embedded/impacted third molars are to be harvested for successful autogenous transplantation.

A histological and micro-CT investigation in to the effect of NGF and EGF on the periodontal, alveolar bone, root and pulpal healing of replanted molars in a rat model - a pilot study

BACKGROUND

This study aims to investigate, utilising micro-computed tomography (micro-CT) and histology, whether the topical application of nerve growth factor (NGF) and/or epidermal growth factor (EGF) can enhance periodontal, alveolar bone, root and pulpal tissue regeneration while minimising the risk of pulpal necrosis, root resorption and ankylosis of replanted molars in a rat model.

METHODS

Twelve four-week-old male Sprague-Dawley rats were divided into four groups: sham, collagen, EGF and NGF. The maxillary right first molar was elevated and replanted with or without a collagen membrane impregnated with either the growth factors EGF or NGF, or a saline solution. Four weeks after replantation, the animals were sacrificed and the posterior maxilla was assessed using histological and micro-CT analysis. The maxillary left first molar served as the control for the corresponding right first molar.

RESULTS

Micro-CT analysis revealed a tendency for all replanted molars to have reduced root length, root volume, alveolar bone height and inter-radicular alveolar bone volume. It appears that the use of the collagen membrane had a negative effect while no positive effect was noted with the incorporation of EGF or NGF. Histologically, the incorporation of the collagen membrane was found to negatively affect pulpal, root, periodontal and alveolar bone healing with pulpal inflammation and hard tissue formation, extensive root resorption and alveolar bone fragmentation. The incorporation of EGF and NGF did not improve root, periodontal or alveolar bone healing. However, EGF was found to improve pulp vascularisation while NGF-improved pulpal architecture and cell organisation, although not to the level of the control group.

CONCLUSIONS

Results indicate a possible benefit on pulpal vascularisation and pulpal cell organisation following the incorporation of EGF and NGF, respectively, into the alveolar socket of replanted molars in the rat model. No potential benefit of EGF and NGF was detected in periodontal or root healing, while the use of a collagen membrane carrier was found to have a negative effect on the healing response.

Autotransplantation of immature third molars using a computer-aided rapid prototyping model: a report of 4 cases

INTRODUCTION

Autotransplantation of immature teeth can be an option for premature tooth loss in young patients as an alternative to immediately replacing teeth with fixed or implant-supported prostheses. The present case series reports 4 successful autotransplantation cases using computer-aided rapid prototyping (CARP) models with immature third molars.

METHODS

The compromised upper and lower molars (n = 4) of patients aged 15-21 years old were transplanted with third molars using CARP models. Postoperatively, the pulp vitality and the development of the roots were examined clinically and radiographically. The patient follow-up period was 2-7.5 years after surgery.

RESULTS

The long-term follow-up showed that all of the transplants were asymptomatic and functional. Radiographic examination indicated that the apices developed continuously and the root length and thickness increased. The final follow-up examination revealed that all of the transplants kept the vitality, and the apices were fully developed with normal periodontal ligaments and trabecular bony patterns.

CONCLUSIONS

Based on long-term follow-up observations, our 4 cases of autotransplantation of immature teeth using CARP models resulted in favorable prognoses. The CARP model assisted in minimizing the extraoral time and the possible Hertwig epithelial root sheath injury of the transplanted tooth.

Regional odontodysplasia: orthodontic treatment and transplantation of premolars

Regional odontodysplasia is a rare and unique dental anomaly involving both dentitions, but mostly the teeth of 1 quadrant. This report describes the combined surgical and orthodontic treatment of a boy with regional odontodysplasia. The mandibular right central and lateral incisors and the canine (as well as the deciduous predecessors) were affected. In a 2-step procedure, the maxillary right and left second premolars were autotransplanted to the affected area. The extraction sites in the maxilla were closed, and a good functional occlusion was established.

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

Autotransplantation is often performed to replace a missing tooth, but tooth autotransplantation has been reported in fewer teeth with complete root formation than those with incomplete root formation. The aim of this prospective study was to evaluate the factors that affect the prognosis of autotransplantation of teeth with complete root formation. 109 patients with 117 transplants were studied. Of the 117 transplants investigated, 14 (12%) failed during the observation period. The overall 1-year survival rate was 96%; the 5-year survival rate was 84%. The major causes of failure were unsuccessful initial healing and replacement root resorption with periodontal inflammation. Factors significantly associated with unsuccessful transplantation, in single factor analysis, were age 40 years or more, molar tooth as donor, probing pocket depth to 4mm or more, history of root canal treatment, multi-rooted teeth and fixation with sutures. Pocket depth of 4mm or more and history of root canal treatment appeared to increase the risk of unsuccessful transplantation in multivariate analysis. It is suggested that the pocket depth of the donor tooth and history of root canal treatment are related to the healing of paratransplantal tissue and root resorption.

Avulsion and replacement of the tooth element fractured at the level of the middle 1/3: a case report

Dental trauma continues to cause loss of teeth, particularly in the anterior region of the maxilla. Reimplanting the tooth with the fragment repositioned by turning it through 180 degrees presents a conservative treatment option that makes it possible to keep a tooth, at first indicated for extraction, functioning and with a satisfactory esthetic appearance.

Time of endodontic treatment in autogenic transplants of mature teeth: Histological study in dogs

OBJECTIVE

Root canal therapy is often recommended after mature tooth transplantation. The aim of this work was to histologically evaluate, in dogs, the best time for root canal treatment in autogenic transplants of teeth with complete root formation.

STUDY DESIGN

Mandibular lateral incisors of 8 dogs were extracted and transplanted to the homologous alveolus, endodontically treated after 15 (Group I) or 40 (Group II) days, and processed for routine histological evaluation. Tissue responses on the root surface were evaluated by light microscopy and classified as normal periodontium, active inflammatory root resorption, favorable healing, and unfavorable healing.

RESULTS

The mean of normal periodontal tissue was in 88.6% in Group I and 79.4% in Group II. There were no significant statistical differences between the groups in all analyzed parameters.

CONCLUSION

The results indicated that endodontic therapy can be postponed for 40 days postoperatively when the tooth stability is higher.