Effect of 3D printed replicas on the duration of third molar autotransplantation surgery: A controlled clinical trial

BACKGROUND/AIM

This study aimed to develop a protocol that combines cone-beam computed tomography (CBCT), software, and 3D printing to design 3D replicas for tooth autotransplantation. The goal was to evaluate the impact of this approach on the extraoral time of the donor teeth and the total surgical time, thereby enhancing surgical efficiency and outcomes.

MATERIALS AND METHODS

A non-randomized trial (protocol 10.1186/ISRCTN13563091) was conducted at Riga Stradins University, enrolling 46 patients (13-22 years old) who required molar extraction and possessed a non-erupted third molar. The patients were sequentially assigned to a 3D replica group (24 patients) or a control group (22 patients). The primary outcome measured was the extra-alveolar time of the donor tooth, and the secondary outcome was the total duration of surgery. Both were assessed using a sample size capable of detecting a 10-min difference. A generalized linear model adjusted for various factors was used to test for significant time differences (p < .05) between the groups.

RESULTS

Forty-six patients were included in this analysis. The effect of using 3D replicas was not statistically significant and was associated with a decrease in the extraoral time of the donor tooth in seconds (β = -9.35, 95% CI [-40.86, 22.16]). For the total surgical time in minutes, the use of 3D replicas had a statistically significant impact, reducing the operation duration in minutes (β = -13.42, 95% CI [-24.50, -2.34]). No early complications were observed in either group, with all teeth present at 3-4 weeks post-surgery.

CONCLUSIONS

The integration of 3D printing technology can enhance the efficiency of autotransplantation surgeries, primarily by reducing surgical time.

New complementary alternatives in third molar autotransplantation: A systematic review

BACKGROUND

Dental autotransplantation (DAT) is defined as the replacement or direct transfer of an impacted, semi-impacted or erupted tooth to a donor site, either to a post-extraction socket or to a surgically created socket within the same individual. The use of new technological advances, such as 3-D dental models based on computer-aided design, among others, have been reported to improve the success rate of DAT. Therefore, we aimed to perform a systematic review to explore the possible benefits that the use of these innovative techniques can provide when applied to DAT.

MATERIAL AND METHODS

The literature search was conducted in PubMed, Scopus, and Web of Science databases following the PRISMA guidelines. The research question was: "Are computerized technological advancements a useful tool for improving the success of third molar autotransplantation technique?

RESULTS

The initial literature search identified 195 articles, of which only 11 were included for qualitative analysis. All studies used 3D dental models based on computer-aided design data. Surgical guides and stereolithographic models were used by 4 and 1 study respectively. A total of 91 transplanted teeth were evaluated, out of which only 88 were considered within the parameters of clinical success (96.7%). Only 7 out of the 11 articles reported the specific autotransplanted tooth, being mandibular third molars the most prevalent autotransplanted teeth.

CONCLUSIONS

Although the application of new technologies for DAT increases the success rate of this technique, further primary studies are still needed to address long-term teeth survival rates and complications. The cost and availability to implement the integration of these techniques to DAT may be a variable to consider, as this can be a limitation for some patients or for low-income countries.

Bilateral Digitally Aided Tooth Autotransplantation: A 2-Year Case Report

Tooth autotransplantation is an effective treatment to replace missing teeth. Digital planning can facilitate successful autotransplantation. Guiding templates are highly recommended when performing cases in healed ridges in the posterior area to reduce excessive bone loss and increase the chances of fitting the donor tooth in the new socket. This case report highlights the use of 3D planning tools and fully guided drilling templates for successful tooth autotransplantation in the posterior area. Two tooth autotransplantations were performed in a 51-year-old patient using mandibular third molars to replace hopeless mandibular first and second molars. Root canal treatments were carried out before the surgeries, and different alveoloplasty techniques were used in each recipient area. The prosthetic phase was carried out after 9 months. Both teeth were asymptomatic, functional, and exhibited no signs of resorption or apical radiolucency and showed complete regeneration of the periodontal apparatus at the 2-year follow-up.

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.

Effect of cryopreservation of teeth on the structural integrity of dentin

The autotransplantation of teeth after cryopreservation has become an increasingly viable method for whole tooth replacement. While the immediate success rates are quite high, damage introduced by cryopreservation within the dentin or enamel could be detrimental to the durability of these teeth.

OBJECTIVE

to determine whether cryopreservation alters the microstructure of dentin or causes a reduction of its resistance to mechanical failures.

METHODS

Third molars were obtained from young donors (18≤age≤30yrs) and subjected to a cryopreservation protocol involving storage for 10days in cryoprotectant solution at -196°C. After treatment, the mid-coronal dentin was characterized in terms of its elastic modulus, strength and fatigue behavior. Scanning electron microscopy and Raman spectroscopy were used to evaluate the microstructure and integrity of collagen after cryopreservation.

RESULTS

There was no significant difference in the elastic modulus or flexural strength between dentin from the cryopreserved and non-cryopreserved (control) teeth. However, the cryopreservation treatment caused a significant decrease in the fatigue strength of dentin with respect to the controls, with average reduction of nearly 20%. While there were no differences apparent in the collagen matrix or fracture surfaces between the cryopreserved and control groups, the microstructure of dentin from the cryopreserved teeth exhibited unique features and damage that appear to have caused the decrease in durability.

SIGNIFICANCE

Autotransplantation of cryopreserved teeth may be a viable option for whole tooth restorations, but hidden damage within the dentin could render these teeth more susceptible to mechanical failures by fatigue and fracture.

Autotransplantation: An Alternative to Dental Implants- Case Report With 4-Year Follow-Up

Autotransplantation can be a viable alternative to dental implant placement for partially edentulous patients when case selection and surgical procedures are performed properly. Moreover, in the event of a failed autotransplantation, implant placement may still be possible. Autotransplantation offers several benefits compared with dental implants, however the surgical procedure is technique sensitive. This case report demonstrates the clinical steps and healing process of an autotransplanted third molar tooth with complete root formation with a 4-year follow-up.

Impacted third molar transplantation on the malpracticed extraction socket

Autotransplantation with or without endodontic therapy is regarded as an alternative treatment option for the replacement of missing teeth. A primary responsibility of a maxillofacial surgeon is to reverse any malpractice to promote successful outcomes and improve the patient's quality of life. This paper presents a malpractice case of incorrect extraction of the lower second molar instead of the impacted third molar. A simple technique of transplanting the impacted third molar to the site of the extracted second molar is introduced by a maxillofacial specialist in Ghana. By making an intentional root socket and fixation without using additional appliances, a novel second molar was achieved with complete recovery. This patient was followed after transplant for a four-year period with the best satisfaction.

FUNDING

A grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea. (HI15C0689).

A New Method Using Autogenous Impacted Third Molars for Sinus Augmentation to Enhance Implant Treatment: Case Series with Preliminary Results of an Open, Prospective Longitudinal Study

PURPOSE

This prospective longitudinal study reports on the results in patients given autologous tooth material for augmentation in a sinus elevation procedure.

MATERIALS AND METHODS

Six patients with inadequate bone supply for augmentation in the maxillary posterior tooth region and at least one impacted maxillary third molar underwent sinus elevation surgery with lateral access using the particulate tooth material. One of the patients received four implants during the same session, while the other patients had a total of 15 implants placed after a healing phase of an average 5.5 months. Drill cylinders collected from the implant bed during the procedure were subjected to histologic/immunohistochemical evaluation.

RESULTS

All six patients showed normal and unobtrusive postoperative healing, having undergone prosthetic restoration up to 5 years before. The average peri-implant probing pocket depth after a period of up to 5 years ranged between 1.86 mm (mesial and lingual) and 2.07 mm (distal and buccal). No bleeding could be triggered with any of the peri-implant probes. The average peri-implant bone resorption measured during the first year was up to 0.63 mm, with the lowest being 0 mm and the maximum 2.9 mm. Peri-implant bone remained stable for the follow-up time of up to 5 years. Histologically, six biopsy specimens collected from five patients showed osteoconductive osteogenesis with encapsulation of tooth enamel and dentin portions and partial resorption of the tooth components. Cementum shares were no longer discernible. Immunohistochemical assessment showed intense new vessel formation that could be observed in the area of loose stroma of reorganized tissue in the augmented area.

CONCLUSION

Within the limits of these preliminary results and with adequate consideration of the small number of patients included, the use of autogenous crushed tooth material from impacted third molars may represent an alternative augmentation material for use in sinus elevation procedures.

Root and Root Canal Morphology of Human Third Molar Teeth

Successful root canal treatment depends on having comprehensive information regarding the root(s)/canal(s) anatomy. Dentists may have some complication in treatment of third molars because the difficulty in their access, their aberrant occlusal anatomy and different patterns of eruption. The aim of this review was to review and address the number of roots and root canals in third molars, prevalence of confluent canals in third molars, C-shaped canals, dilaceration and fusion in third molars, autotransplantation of third molars and endodontic treatment strategies for third molars.

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.

Results after wisdom tooth transplantation. A retrospective study

Wisdom tooth transplants offer youth the possibility of biologically fixed tooth replacement in cases of premolar agenesis or premature loss of a molar. In the present study, 57 transplants of third molars were reviewed and evaluated retrospectively on preoperative findings (root growth stages, extraction sites, indication for transplantation), on postoperative clinical findings (local gingivitis, periodontal probing values, tooth mobility, percussion sound and percussion pain) and on radiological findings (tertiary build-up of dentin, osseous periradicular conditions, progress of root growth). Only the transplants which healed with a vital pulp and in a periodontally healthy state were considered successful. Upper and lower wisdom teeth having 50% to 75% root growth progression were transplanted. The postoperative follow-up observation period averaged 26.4 months. The success of a wisdom tooth transplantation was not influenced by the root growth stage (p = 1), the extraction location of wisdom teeth (p = 0.45), or the feasibility for a transplantation (p = 0.56). Three teeth showed pulpal necrosis with apical periodontitis and were counted as failures. The success rate was rather high with 54 out of 57 transplants (94.7%), therefore wisdom tooth transplantations, with careful selection of a suitable graft and its gentle removal, can be described as a good predictable treatment.

Tooth autotransplantation in orthodontic patients

AIM

The aims of this report are to present three cases of autotransplantation along with a review of the indications, selection criteria for patient donor and recipient sites, and the major steps in the surgical procedure.

BACKGROUND

Autogenous tooth transplantation, or autotransplantation, is the surgical movement of a tooth from one location in the mouth to another in the same individual. It can be a good treatment option in many cases if the dentist knows the implications, indications, and contraindications.

CASE DESCRIPTIONS

Three cases with different treatment indications and plans are presented. All showed autotransplantation of teeth as part of orthodontic treatment. It emphasized the benefits of this treatment modality such as new bone formation and lower costs. One case, a rare example of multiple congenitally missing teeth treated by autotransplantation, also was presented.

SUMMARY

As shown in these case reports, there are instances where the autotransplantation of teeth is appropriate and may possibly simplify future planned orthodontic or prosthodontic treatment.

CLINICAL SIGNIFICANCE

Tooth autotransplantation is an easy and good treatment option, applicable in a lot of cases, substituting different types of prostheses, including dental implants.

Autotransplantation of impacted teeth: a report of 3 cases and review of the literature

Transplantation of one's own teeth from one site to another is called dental autotransplantation. Because tooth transplantation allows dentofacial development and maintains alveolar bone volume, it is a viable treatment method, especially in young patients with missing teeth or tooth agenesis. Three cases are presented in which missing or agenetic teeth were replaced by autotransplantation of impacted teeth. This article illustrates the option of using impacted teeth as a viable reservoir for autotransplantation in young patients with missing permanent teeth.

Autotransplantation of an unerupted wisdom tooth germ without its follicle immediately after removal of an impacted mandibular second molar: a case report

An impacted left mandibular second molar (tooth 37) was extracted, but most of its dental follicle remained in the socket. The crown and dental papilla of an unerupted, left mandibular third molar (tooth 38) were then placed into the socket of tooth 37. Successful interaction between the dental follicle of tooth 37 and the crown and dental papilla of tooth 38 led to the formation of a new tooth 37 at the recipient site. This suggests that the dental follicle may function non-specifically with the crown and dental papilla of other tooth germs.

[Use of laser Doppler flowmetry in dentistry]

An early determination of pulpal vitality is crucial with respect to a correct differential diagnosis of revascularisation or necrosis and its treatment. The use of sensibility tests (cold, heat, electrical pulp test) in combination with X-ray are commonly promoted. However these tests are arbitrary, based on sensations and therefore not always reliable. In such situation the registration of 'real' pulpal blood flow and hence pulp vitality will be more than an added value. The most studied and well documented method is laser Doppler flowmetry (LDF) as it is non invasive, direct and objective. In this article we describe blood flow, LDF and its characteristics, advantages and disadvantages of this method and the newest developments regarding LDF. Despite a low implementation of LDF in Belgium, this technique proved to belong indisputable to the basic assets of a dental clinic. A number of cases are described to demonstrate the efficacy and added value of LDF in assessing tooth vitality.

[Autotransplantation of an immature tooth]

Autogenous tooth transplantation is indicated in young people treated by orthodontology, especially when they present with damaged first molars requiring extraction. This therapeutic alternative with a favourable prognosis is an elegant solution after a single tooth loss.

Autogenous transplantation of teeth with complete root formation: two case reports

AIM

Autotransplantation is an alternative treatment for replacing lost teeth when suitable donor teeth are available. This paper presents two cases of successful autogenous tooth transplantation.

SUMMARY

Two third molars with complete root development were autogenously transplanted from their original sockets into new recipient sites on the same side of the mouth, one in the maxilla and one in the mandible. In both cases, the third molars were transplanted immediately after the first molar extractions. To provide better adaptation of the donor teeth, the recipient alveolar sites were remodelled using surgical burs. Semi-rigid splints were maintained for 45 and 15 days, respectively. Root canal treatment commenced one a week after transplantation and the canals were medicated with a calcium hydroxide paste before they were filled. Clinical and radiographic findings after 5 and 3 years of follow-up, respectively, are discussed in relation to the literature.

KEY LEARNING POINTS

Autogenous transplantation of teeth with complete root formation may be considered as a viable treatment option to conventional prosthetic and implant rehabilitation for both therapeutic and economic reasons. Careful surgical and endodontic procedure, together with careful case selection may lead to satisfactory aesthetic and functional outcomes.

Treatment of external inflammatory root resorption after autogenous tooth transplantation: case report

This paper describes a case of autogenous tooth transplantation. An external inflammatory root resorption developed in a 30-year-old female patient and was successfully treated with the placement of calcium hydroxide-based intracanal dressings. Autotransplantation of tooth 32 into the extraction socket of tooth 30 was carried out with no intraoperative complications and uneventful postoperative course. However, the patient did not appear on the 14th postoperative day to initiate endodontic therapy of the transplanted tooth. She did not return for 3 months, at which time the clinical and periapical radiographic examinations revealed the presence of external inflammatory root resorption. Endodontic treatment was initiated immediately. Root canals were prepared and filled with a calcium hydroxide-based intracanal dressing (Calen paste), changed every 21 days during a 6-month period, and were thereafter obturated with Sealapex calcium hydroxide-based sealer and gutta-percha points. After 2 years of follow-up, the transplanted tooth was symptom free with no exacerbated sensibility to percussion, normal mobility, occlusion, and masticatory function. Probing revealed no periodontal pockets or other pathological signs. Radiographic examination showed the periradicular area with normal appearance, completely healed resorption areas, and presence of an intact lamina dura.

Effect of different splinting methods and fixation periods on root development of autotransplanted immature third molars

PURPOSE

The aim of the present study was to assess the influence of suture splinting for 1 week or rigid fixation for 4 weeks on final root length, root length increment, and mobility of autotransplanted immature third molars.

PATIENTS AND METHODS

The sample consisted of 63 patients with a total of 65 transplanted immature third molars. All transplants had reached one-half (n = 29) to three-fourths (n = 36) of their expected root length. In 24 of the transplants, postoperative fixation was carried out with a rigid acid-etch composite and wire splint for 4 weeks (rigid group), and in 41 transplants, with a suture splint for 1 week (suture group). The fixation method depended on the initial stability of the transplants. All transplants were followed up clinically and radiologically for a mean period of 3.9 years.

RESULTS

Transplants in the rigid group revealed a significantly lower final root length ( P = .002) and root length increment ( P = .001) than those in the suture group. The differences were found to be more pronounced in transplants at earlier developmental stages. No differences were found in transplant mobility.

CONCLUSIONS

The results of the present study indicate that prolonged rigid fixation of autotransplanted immature third molars has a significantly negative influence on final root length and root length increment, especially in transplants at earlier developmental stages.

Success rate of autotransplanted teeth without stabilisation by splints: a long-term clinical and radiological follow-up

The purpose of this retrospective study was to assess the results after a follow-up of 10 years of autotransplantation of canines and third molars without the use of any apparatus for stabilisation. A total of 96 teeth were transplanted and 83 were successful (86%). The technique is easy, reliable, and effective.

Autotransplantation of an impacted third molar: an orthodontic case report

This case report describes the use of autotransplantation as part of an orthodontic treatment plan where there was early loss of an upper molar tooth secondary to irreversible pulpitis. An impacted lower third molar, which had symptoms of pericoronitis, was transplanted into the upper left second molar socket. Fixed orthodontic treatment, to correct the patient's initial complaint of crowding, was completed in 22 months. The transplanted tooth remained vital and functional throughout.

Mandibular third molar autotransplantation--literature review with clinical cases

Autotransplantation of mandibular third molars in a precocious phase of development is indicated when a substitute for adjacent compromised or missing molars is needed, and when mesial movements of the posterior teeth, the resultant loss of space, and overeruption of opposing teeth and consequent changes in the occlusion must be avoided. Provided that the apices of the mandibular third molar are immature, the immediate replacement of a lost or compromised tooth usually ensures a good outcome. Transplantation of third molars helps to maintain alveolar bone and enables endosseous implantation without requiring bone regeneration. We present examples of transplantation of mandibular third molars and review the factors that affect the success or failure of this procedure, such as atraumatic extraction and adequate immobilization of the transplanted tooth and root development after transplantation. Sex or age seem to have no effect on the final outcome.

Autotransplantation of immature third molars into edentulous and atrophied jaw sections

The aim of the present study was to assess the results after transplantation of 85 immature third molars. Recipient site conditions varied and different surgical techniques were used. The long-term results after preparation of a new alveolus, splitting osteotomy of the alveolar process or use of free bone autografts were compared with the results after transplantation into a fresh extraction site (control group). Transplantations into prepared sockets showed equal results to the control group (94% respectively). Transplantations in connection with free bone autografts (84%) or after splitting osteotomy of the alveolar process (63%) showed poorer success rates, the differences between the latter and the control group being statistically significant. A possible correlation to revascularization disturbances of the pulp due to an insufficiency of the recipient site or to postoperative infection is suspected. The results show that transplantation of immature third molars is a safe, useful procedure when appropriate conditions of the recipient site are present. Where the alveolus is atrophic, a splitting osteotomy should be performed only in exceptional cases and preference should be given to alternative methods such as primary bone augmentation or bone-regenerative procedures.

Influence of orthodontic derotation and extrusion on pulpal and periodontal condition of autotransplanted immature third molars

The aim of this study was to determine the influence of orthodontic treatment on the pulpal and periodontal condition of 91 transplanted immature third molars. In patients with atrophy of the alveolar process or unfavorable root morphology, transplants had to be placed in extreme rotated or infraoccluded positions. After 3 to 6 months, these transplants were derotated (45 degrees to 90 degrees) to a correct position in the dental arch (derotation group; n = 28) or extruded to the occlusal plane (extrusion group; n = 21). Finally, approximal spaces were closed in both groups. A sample of 42 transplanted third molars with no orthodontic treatment need served as the control group. All transplants were followed clinically and radiologically for a mean period of 4.0 years. With respect to pulpal and periodontal conditions, no significant differences were observed between the control and the extrusion group. In contrast, compared with the control group, transplants in the derotation group had a significantly poorer pulpal and periodontal condition. In the derotated transplants, a significant correlation was detected between pulp necrosis and orthodontic treatment of multi-rooted transplants. This study indicates that orthodontic extrusion and minor lateral movements of autotransplanted immature third molars, as well as rotation of single-rooted third-molar transplants, represent no additional risk to transplant survival. In contrast, rotation of multi-rooted transplants seems to initiate later severance of the vascular and nerval supply to the pulp.

Facial asymmetry case with multiple missing teeth treated by molar autotransplantation and orthognathic surgery

Autotransplantation is an alternative treatment in cases of missing teeth. Autotransplantation of teeth can lead to significantly shorter treatment time and an improved treatment result in certain cases of tooth loss, wherever a suitable tooth is available and the anatomic circumstances permit it. The presented case report, treated successfully with molar autotransplantation and orthognathic surgery, had a number of missing teeth and facial asymmetry.

Potential efficacy of GTR and autogenous bone graft for autotransplantation to recipient sites with osseous defects: evaluation by re-entry procedure

This clinical study aimed to evaluate the effectiveness of guided tissue regeneration (GTR) or autogenous bone graft for autotransplantation to recipient sites with an osseous defect, based on a substantial assessment of bone regeneration using a re-entry procedure. Three cases of autotransplantation of a wisdom tooth to the position of first molar, in which moderate to extensive bone loss at the buccal alveolar plate was observed, were studied. Each tooth was transplanted with no additional treatment, or in conjunction with GTR or autogenous bone graft. Four to 20 months after surgery, a re-entry procedure was performed to visually examine healing. When GTR membrane coverage or bone graft was used, previously absent alveolar bony plates regenerated and the initially exposed roots were covered with newly formed bone, while no bone formation was observed in the case without any additional procedure. These results demonstrate that both GTR and autogenous bone graft are beneficial for obtaining bone regeneration in autotransplantation to defective recipient sites, contributing to retaining space and excluding the contact of gingival connective tissue with periodontal ligaments.

Influence of orthodontic movement on root length of autotransplanted immature third molars

The aim of this study was to investigate the influence of orthodontic extrusion or derotation on final root length and root length increment in 75 autotransplanted immature third molars. Depending on the condition of the recipient site and the root morphology, transplants had to be placed in extreme rotated or infra-occluded position. Three to six months after transplantation, these transplants were derotated to a correct position in the dental arch (derotation group, n = 19) or extruded to the occlusal plane (extrusion group, n=18). Thirty-eight transplants with no orthodontic treatment need served as controls (control group). Transplants were followed clinically and radiologically for a mean period of 4.0 yr. No statistically significant differences were observed between the extrusion and the control groups or between the single-rooted transplants in the different groups. In contrast, multi-rooted transplants in the derotation group showed a statistically significantly shorter final root length than multi-rooted transplants in the extrusion and the control groups. However, as these differences may be considered to be of minor clinical importance (<1 mm), it can be concluded that the effect of orthodontic movement on root development of transplanted immature third molars is of only negligible clinical significance.

A prospective study on transplantation of third molars with complete root formation

OBJECTIVE

The study objective was to evaluate the prognosis for autotransplantation of third molar teeth with fully developed roots followed by endodontic treatment on the basis of a time-table analysis.

STUDY DESIGN

A total of 50 third molars with completely developed roots were autotransplanted to replace a lost first or second molar in the same number of admitted patients. Root canal treatment was started 3 to 4 weeks later. Clinical and radiographic checkup of the transplanted and root-filled third molars was done annually according to a predesigned record form. Descriptive statistics including a life table and statistical analysis were performed.

RESULTS

The cumulative survival rate during 4 years' follow-up was 81.4%. In all, 7 transplants were lost during the follow-up time, 4 of them due to marginal periodontal pathosis and the other 3 due to root resorption. None of the root resorptions was observed before the second postoperative year. The radiographic periapical status was considered normal in 96% of the transplants at the latest follow-up visit.

CONCLUSIONS

Autotransplantation of mature third molar teeth is a reasonable treatment alternative to conventional prosthetic rehabilitation or implant treatment in cases of partial edentualism from both a therapeutic and an economic point of view.

[Root growth after wisdom tooth transposition. Case documentation with proposal for a radiologic method to quantify growth]

OBJECTIVES

To introduce a method for assessment of root growth on panoramic radiographs exemplified by a case report on an autotransplanted lower third molar.

MATERIAL AND METHODS

A lower left third molar (T) with incomplete root formation was transplanted for replacement of the lower left first molar in an 18-year-old woman. T was monitored clinically and, together with its neighboring lower second molar (37) with constant root length, also radiographically by means of two panoramic radiographs (OPGs) produced 12 days and 20 months postoperatively. A method for calculation of the root length as a multiple of the crown length is introduced, using accurately reproducible landmarks defining the coronal and apical endpoints of the examined tooth in all OPGs of the series. This method minimizes error due to different magnifications within the set of radiographs.

RESULTS

Using the method introduced, the root length of the constant tooth 37 varied at 2.7% within the set of OPGs, whereas it revealed a 5.6% variation when the evaluation was based on direct measurement. Based on the described method, T revealed a postoperative root growth of approximately one-third of its final length and showed clinically no pathological findings during the observation period.

CONCLUSIONS

Our results indicate that with the described method root growth assessment on panoramic radiographs is more accurate than with direct measurement.

Autotransplantation of endodontically treated third molars

OBJECTIVE

To determine the success rate in autotransplantation of endodontically treated third molars.

DESIGN

A descriptive study.

PLACE AND DURATION OF STUDY

This study was carried out at Armed Forces Institute of Dentistry (AFID), Rawalpindi (Pakistan) from January 2002 to December 2002.

PATIENTS AND METHODS

A total of 50 patients meeting the inclusion criteria were selected who had their first or second molars in unrestorable condition with intact third molars. The donor teeth were extracted after the preparation of recipient site. After endodontically treated in vitro the donor teeth were carried to the recipient site and immobilized. Postoperative variables were recorded and analyzed on SPSS version 10.

RESULTS

The overall success rate after six months of the transplantation of third molars was 88% with complete root formation after endodontic treatment. All the patients(12%) who had complaints were more than 35 years of age.

CONCLUSION

Third molars are good substitute for the unrestorable first or second molars and would be as effective as endosseous implants. The procedure is likely to have complications in the advanced age group.

Use of third molar transplantation for closure of the oroantral communication after tooth extraction: a report of 2 cases

OBJECTIVE

This clinical report introduces a promising and unique method for the immediate closure of the oroantral communication (OAC) after tooth extraction: the use of the transplanted third molar with closed apices.

STUDY DESIGN

In 2 adult patients, OAC caused by the extraction of an upper molar was immediately closed by using a transplanted third molar with complete root formation. After tooth extraction at the recipient site, OAC with perforated mucosa of the sinus floor was confirmed and the donor third molar was transferred to the prepared recipient socket. Endodontic therapy of the transplanted third molar began at 3 weeks after surgery, and prosthetic treatment was completed at 5 months after the operation. These 2 patients were carefully observed both clinically and radiographically.

RESULTS

Closure of the OAC was successfully performed, and the transplanted teeth became fixed with the passage of time in these 2 patients. Root resorption did not occur, and good functional results were obtained without any complications.

CONCLUSIONS

Tooth transplantation of a mature third molar for closure of the OAC is a simple and excellent method because the transplanted tooth not only closes the communication to the maxillary sinus, but it also satisfactorily functions at the recipient site during mastication, even in adult patients.

Results of transplanting developing third molars as part of orthodontics space management. Part 2: results following the orthodontic treatment of transplanted developing third molars in cases of aplasia and premature loss of teeth with atrophy of the alveolar process

MATERIAL AND METHODS

The aim of this study was to assess the effects of atrophy of the alveolar process and subsequent orthodontic treatment on the transplantation results of developing third molars. The material consisted of 35 teeth transplanted to an atrophied alveolar process. 19 of these teeth were treated orthodontically subsequent to transplantation. The control group consisted of 61 developing molars transplanted to a new extraction socket. The transplanted teeth were followed up clinically and radiographically for a mean period of 3.2 years.

RESULTS

The success rate was 85% for transplants to new extraction sockets and 84% for transplants to atrophied jaw sections with subsequent orthodontic treatment. In contrast, transplants to atrophied jaw sections without subsequent orthodontic treatment showed a significantly (p < or = 0.001) lower success rate of only 37.5%. These poorer results were due to persistent infraocclusion and ankylosis.

CONCLUSIONS

Even in cases with atrophy of the alveolar process, a transplantation with subsequent orthodontic treatment represents a promising treatment concept, whereas teeth without subsequent orthodontic treatment showed a lower success rate. Orthodontic tooth movement had no negative effect on the healing rates of transplanted developing third molars.

Autotransplantation of immature third molars: influence of different splinting methods and fixation periods

Different data were published documenting the influence of fixation methods and periods on the outcome of autotransplantations of teeth. Besides studies reporting increased ankylosis and disturbances of pulpal revascularization following rigid or extended fixation, there are studies revealing no connection in this matter. The clinical and radiological results of 76 transplanted germs of third molars were to be assessed after a rigid fixation for 4 weeks or after a suture splinting for 7 days and compared with each other. The choice of fixation method depended on the initial stability of the transplant. After a mean observation period of 3.4 years (range 1.0-6.1 years), 92.9% of the teeth stabilized with a suture, but only 73.5% fixed with an acid-etch composite and wire splint could be classified as successful (P = 0.029). The significant increases in ankylosis (P = 0.036) and pulp necrosis (P = 0.041) were the factors for the less favorable results of the rigidly fixed teeth. Our data support the results of other experimental and clinical studies with regard to the negative influences of an extended and rigid fixation on the success of tooth transplantation. However, apart from a correlation with the method and period of fixation, we also suspect the influence of an incongruity between the transplant and recipient site.

Results of transplanting developing third molars as part of orthodontic space management. Part 1: clinical and radiographic results

PATIENTS AND METHOD

The aim of the present study was to contribute to a more accurate indication and better integration of developing third molar transplantation into orthodontic space management, using the results gleaned from the authors' own pool of patients. For this purpose, a clinical and radiographic examination of 61 transplanted developing molars in 57 patients was carried out after an average of 3.3 years.

RESULTS

The overall success rate was 85%. Failure was due in 10% of cases to impaired periodontal healing (inflammatory root resorption, ankylosis, or increased pocket probing depths) and in 5% of cases to insufficient or arrested postoperative root development accompanied by increased transplant mobility. The incidence of postoperative cessation of further root development was significantly higher (p = 0.011) in transplants at early developmental stages, which also had a negative impact on the final root length, the crown-root ratio and the mobility values of these transplants.

CONCLUSIONS

The transplantation of developing third molars should be given stronger consideration in treatment plans for orthodontic space management although it represents a real alternative to orthodontic space closure only in exceptional cases. However, unlike implantological or prosthodontic treatment, it offers an opportunity to replace a missing or non-retainable tooth with a patient's own vital and fully functional tooth, provided the appropriate transplant is selected.

Response of autotransplanted teeth to electric pulp testing

OBJECTIVE

The purpose of this retrospective study was to assess the results of third molar autotransplantation by using electric pulp testing (EPT) and to determine the correlation of EPT response and bone formation.

STUDY DESIGN

Fourteen patients with 22 transplanted teeth were studied. The patients had received autotransplantation of third molars and regularly came for follow-up on the third, sixth, ninth, and twelfth months. Postoperative clinical assessment included pain, inflammation of surrounding soft tissues, tooth mobility, and the EPT response. Periapical radiographs were subsequently evaluated during follow-up. The correlation between pulpal response to EPT and bone healing was analyzed.

RESULTS

Most of the teeth had normal mobility within 3 months, which corresponded to bone formation. Bone healing at the recipient sites completely occurred within 6 months, and more than 50% had lamina dura. The teeth with EPT response increased to 95% within 12 months. There was no significant association between the EPT response and bone formation.

CONCLUSIONS

The EPT response subsequently increased with time, and it seemed to be unchanged after 1 year.

Autogenous dental transplants: description of a clinical case

The dental transplant was already in use more than 2,000 years ago, reaching a peak in the Middle Ages, but it was only after the 1950s that this subject appeared in the scientific literature. This article describes the case of a young woman whose mandibular left second and right first molars had to be extracted and were replaced using the maxillary third molars. The positive clinical and radiographic results over a 5-year period encourage the use of this technique.

Clinical application of computer-aided rapid prototyping for tooth transplantation

The maintenance of healthy periodontal ligament cells in the donor tooth is one of the most important factors for successful tooth transplantation. This is achieved by minimizing the extraoral time during the surgical procedure. If a duplicate form of donor tooth could be obtained before extraction, it would be possible to precontour the recipient alveolar bone compatible with the donor tooth, and thereby reduce the extra-oral time of the donor tooth. We obtained a three-dimensional image with the real dimensions of the donor tooth from a CT Highspeed Advantage, allowing a life-sized resin model of the tooth to be fabricated. From 22 clinical cases, we achieved an average total transplantation time of 7.7 min. The average distance between the transplanted root surface and the alveolar bone from 12 available cases was 0.87 mm at the mesial cervix, 0.91 mm at the mesial apex, 0.98 mm at the distal cervix and 1.16 mm at the distal apex on the postoperative radiographs. Clinical data indicate that computer-aided rapid prototyping may be of value in minimizing the extra-oral time and possible injury to transplanted tooth during the process of autotransplantation.

The long-term survival of lower second primary molars in subjects with agenesis of the premolars

This study investigated 41 subjects, 13 male and 28 female, with agenesis of one or both lower second premolars, and with retained lower second primary molars. Intra-oral radiographs of 59 primary teeth were examined to judge the resorption of the mesial and distal roots, and were measured to record infra-occlusion of the primary teeth and tipping of the adjacent permanent teeth. The study commenced at 11-12 years of age. The mean age at the last measurement was 20 years 6 months (SD 3.62, range 13.6-31.8 years). During the observation period, only two of the 59 primary teeth were exfoliated. Five were extracted, two of which were replaced by upper third molar transplants. Beyond the age of 20 years no teeth were lost. Root resorption varied widely between individuals, but was slow. There was no typical pattern for development of infra-occlusion. Mean infra-occlusion was 0.47 mm (SD 1.13) at 11-12 years, increasing by less than 1.0 to 1.43 mm (SD 1.13) at age 17-18 years. At age 19-20 years, 55 per cent of teeth showed infra-occlusion between 0.5 and 4.5 mm, but 45 per cent showed no infra-occlusion. The space between the first molar and first premolar was a mean of 10.35 mm (SD 0.76) at age 10-12 years compared with the mean width of the second primary molar of 10.53 mm (SD 0.51). The space reduced by less than 0.5 mm to 9.95 mm (SD 1.50) at age 17-18 years. If primary molars are present at 20 years of age they appear to have a good prognosis for long-term survival.

A clinical and radiographic study of 25 autotransplanted third molars

This paper is a report on 25 autotransplantations of third molars with complete root formations. The study consists of 23 patients in whom 25 third molars were transplanted. The mean age was 29.6 years (range 20-54). In nine cases third molars were directly transplanted into the new socket. In 11 cases the sockets were widened and made deeper with a bur. In five cases the recipient beds were made by splitting osteotomy of the alveolar region. The transplanted third molars were stabilized with silk sutures, resin, wire splint or circumferential wiring for 1-6 weeks. Two-three weeks after transplantation, the root canals were treated and filled. After operation, the marginal and the periapical conditions were examined clinically and radiographically. The transplanted teeth clinically appeared to become firmer with the passage of time. Progressive root resorption was not found and good results were obtained. This study shows that autotransplantation of third molars with complete root formation produces an acceptable result using the procedures outlined.

Transplanting teeth successfully: autografts and allografts that work

This article suggests tooth transplantation as an alternative to other restorative options. The 10-year success rates for autografts--teeth moved from one location to another in a patient's mouth--range from 60 percent to 95 percent. Allografts, teeth moved from one person to another, are less successful. The authors report on one case of each type of transplant.

[Outcome of wisdom tooth germ transplantation]

In 68 patients, 79 tooth germs of the third molar were transplanted. Out of this group, 43 patients with 50 transplantations under-went a follow-up examination. All surgery was performed by one surgeon. Retrospectively, we tried to establish whether the success of postoperative healing depends on the donor and receiver regions. Crossing the jaw border clearly worsens the prognosis for transplantation. Altogether 9 transplantations turned out to be failures, 7 of which had been transplanted from the upper to the lower jaw. The results of this investigation showed incomplete root development in 34%, the necessity of endodontic treatment in 6% and enlarged periodontal pockets in 8%. Ankylosed teeth were found in 10%; we did not see any root resorptions.

Autogenous transplantation of third molars in irradiated jaws--a preliminary report

Our experience with third molar autotransplants in 2 patients, into an area irradiated at an early age, is described and discussed. It is shown that such autotransplantations are possible.

Replacement therapy utilising autotransplanted wisdom teeth

Loss of 1st and 2nd molars among adolescents due to dental caries is not uncommon in developing countries. Whilst their replacement is indicated, conventional methods of treatment, namely, bridging and dentures are in most cases inaccessible because of prohibitive cost. Given that it is in the same age group that diagnosis of unfavourably embedded wisdom teeth becomes feasible, autotransplantation of the latter to replace the unsalvageable 1st and 2nd molars could be an alternative treatment. Available literature suggests a success rate of over 82% based on follow-up studies of over ten years. Observations at the Dental School Clinic of the University of Nairobi, Kenya, indicate that the time it takes the transplant to 'take' and assume its functional position is 4 to 8 weeks and 2.5 to 3.5 months respectively. Since the method is relatively straightforward, we are of the view that training undergraduates and practising dental surgeons in this technique should enhance utilisation of otherwise "useless" teeth to replace the lost 1st and 2nd molars in occlusal rehabilitation.

Autotransplantation of a tooth using guided tissue regeneration

Autotransplantation is an alternative treatment to replace missing or periodontally-involved hopeless teeth. A prerequisite for performing this procedure is having a recipient site with sufficient bone volume to support the transplant. Often, however, crestal bone resorption following tooth extraction or periodontitis results in a reduced alveolar ridge with inadequate dimensions to properly house the transplant. In these cases, the procedure is contraindicated. A case is presented in which the biologic principle of guided tissue regeneration was used to gain periodontal support around an autotransplanted 3rd molar. The results suggest the potential use of guided tissue regeneration in conjunction with autotransplantation. This may represent a new area in reconstructive dentistry.

Autotransplantation of third molars as treatment in advanced periodontal disease

The aim of this study was to investigate the prognosis of replacing molars with advanced periodontitis by autotransplanted fully developed third molars. The patient sample consisted of 18 subjects, 24-58 years of age. The patients selected had at least 1 molar with advanced periodontal tissue destruction. After extraction of the diseased molar, autotransplantation of a third molar was immediately performed. After a splinting and healing period of 2-3 weeks, endodontic treatment was carried out. The follow-up included recordings of the clinical parameters, probing periodontal pocket depth, probing attachment level, percussion sound, and mobility. Radiographs were taken immediately after the surgical procedure, after 6 months, 1 year, and thereafter annually. The results of this study indicate that autotransplantation may be an alternative treatment procedure for molars with advanced periodontal disease.

Autogenous transplantation of third molars; a rapid new clinical splinting technique

A simple, rapid technique to splint transplanted third molars is presented and illustrated. Stable postoperative fixation is achieved whilst using readily available materials.