Short oral presentations

Friday, 25 May 2018 12.00-17.30 Oral presentations

The scientific programme on this day dedicated to short scientific reports related to tooth transplantation and clinical examples of interesting applications of this treatment modality.

timetitle, author(s)
SHORT ORAL PRESENTATIONS
I Scientific Session
Session Chairmen: Ewa Czochrowska, Marcel Linnsen
12.00-12.15The Amsterdam protocol for premolar autotransplantations
The lecture will be presented by Marjolijn Gilijamse in memory of Jacques Baart
12.15-12.30Tooth autotransplantations in the anterior mandible and maxilla
Gilijamse M, Baart JA, de Cleen M, Swart TJ. Amsterdam, Netherlands
12.30-12.45Primary tooth auto-transplantation for instant rehabilitation of young children with traumatic loss or agenesis of permanent incisors
Tschammler C, Linsenmann R, Nolte D, Germany
12.45-13.00Is autotransplantation a reliable treatment option?
van Westerveld KJH, Verweij JP, Anssari Moin D, Mensink G, van Merkesteyn JPR, Netherlands
13.00-13.15A long-term evaluation of the success of 144 tooth autotransplants
Pinheiro TN, Roldi A, Intra TJA, Nunes FC, Intra JBG, Brasil
13.15-13.30The Patient Perspective and the Survival Rate of Tooth Transplantation
Juslin J, Jääsaari P, Teerijoki-Oksa T, Finland
13.30-13.45Complications and endodontic treatment after autotransplantation of premolars: a retrospective study
de Cleen MJH, Baart JA, Netherlands
13.45-13.55Orthodontic forces and their sequelae on autotransplanted teeth: A literature overview.
Jordan B, Nolte D, Müßig D, Germany/Austria
13.55-14.05Enhancement of Human Periodontal Ligament by Pre-application of Orthodontic Loading
Nakdilok K, Krisanaprakornkit S, Suzuki EY, Suzuki B, Thailand
14.05-14.15Altered expression of pluripotent markers in human periodontal ligament upon application of orthodontic preloading
Phutinart S, Suzuki B, Suzuki EY, Krisanaprakornkit S, Thailand
14.15-14.25 Periodontal ligament preservation during orthodontic tooth movement in human
Promchaiwattana P, Suzuki B, Suzuki EY, Krisanaprakornkit S, Thailand
14.25-14.35Discussion
14.35-15.00Coffee break
II Scientific Session
Session Chairmen: Manfred Leunisse, Paweł Plakwicz
15.00-15.15How can we minimize the risk of External Cervical Resorption during autotransplantation?
Mavridou AM, Eggink E, Linssen M, Barendregt D, P. Lambrechts P, Netherlands/Belgium
15.15-15.25A case of tooth autotransplantation for severe atrophic alveolar combined with orthodontic treatment, bone augmentation and vestibuloplasty
Matsuzawa Y, Abe Y, Japan
15.25-15.35Autotransplantation of a lower cuspid- case presentation
Daian M, Louropoulou A, Pantaleon M, Netherlands
15.35-15.45Exploring the limits of tooth autotransplantation
Streblov J, Czech Republic
15.45-15.55Case report of tooth transplantations in patients over 50 years old
Yoshino K, Tokyo, Japan
15.55-16.05Tooth transplantation: where are the limits?
Novosad M, Marek I, Breclav, Czech Republic
16.05-16.20Three-dimensional imaging and rapid prototyping in autotransplantation: innovation that excites!
van Merkesteyn JPR, Verweij JP, van Westerveld KJH, Anssari Moin D, Mensink G, Netherlands
16.20-16.35Three-dimensional imaging and rapid prototyping in autotransplantation: the (im)possibilities of a technique
Verweij JP, van Westerveld KJH, Anssari Moin D, Mensink G, van Merkesteyn JPR, Netherlands
16.35-16.50CBCT-based tooth autotransplantation – Part I: 3D planning, 3D printing and 3D analysis of treatment outcome.
EzEldeen M, Wyatt J, Stratis A, Jacobs R, Belgium
16.50-17.00CBCT-based tooth autotransplantation – Part II: Surgical technique, follow-up, short and long-term treatment outcome.
Wyatt J, EzEldeen M, Shahbazian M, Jacobs R, Belgium
17.00-17.20Affordable 3D planning for tooth transplantation in all stages of development
van der Meer J, Dick Barendregt D, Netherlands
17.20-17.30Discussion
timetitle, author(s), abstract
SHORT ORAL PRESENTATIONS
I Scientific Session
Session Chairmen: Ewa Czochrowska, Marcel Linnsen
12.00-12.15The Amsterdam protocol for premolar autotransplantations
The lecture will be presented by Marjolijn Gilijamse in memory of Jacques Baart
Jacques A. Baart (VUmc, Amsterdam, NL), Marjolijn Gilijamse (VUmc, Amsterdam, NL), Michiel J.H. de Cleen (Practice limited to endodontics, Amsterdam, NL) and Tjebbe W. Swart (Orthodontist, Gouda and Amsterdam, NL)

Introduction:
At the Department of Oral and Maxillofacial Surgery, Free University Medical Centre (Amsterdam, NL) approximately 4500 autotransplantations were performed between 1986 and 2017. The diagnostic and therapeutic consequences were fitted in a protocol which started with a referral letter or e-mail from the orthodontist including radiographs with a copy to the dentist and the parents of the patient. Over 60% of the autotransplantations were upper 2nd premolar to the position of a missing lower 2nd premolar.

Objectives:
The purpose of the protocol was to minimalize the number and the duration of visits to the hospital, to involve the orthodontist and the dentist in the treatment and post-operative care and to treat potential complication as quickly as possible. This all at low cost and a low radiation dose.

Material and methods:
The OMF-surgeon judges the possibility of the autotransplantation from the referral letter , including a recently made panoramic radiograph. He informs the orthodontist whether auto-transplantation is possible and when the treatment is to be performed. He returns his advice and judgement to the orthodontist, dentist and parents of the patient. He asks if everything is well understood and whether the parents need more information about the procedure, post-operative care, costs and insurance, etc. Almost 80% of all autotransplan-tations are done under local anaesthesia, even if a bilateral transplantation is required. A unilateral procedure takes 30 minutes; a bilateral prodecure 45 minutes. The first control visit is 4 weeks post-operative and the second 1 year post-op. In between these controls the patient is seen by his dentist on a regular base i.e twice a year. The transplanted tooth is tested for mobility, per-cusssion, vertical dimension and rotation (by the orthodontist). An intraoral radiograph is taken and all this information is sent to the OMF-surgeon. Because of a lack of experience, it is often difficult for the dentist to inform the patient and his/her parents. So teleconsulting is the answer. This procedure saves time-consuming visits to the OMF-surgeon. If no further treatment is warranted, the dentist is asked to radiographically check the tooth yearly for a period of 4 years. If and when there are complications (periapical infection, progressive external root resorption) the patient is referred to an experienced endodontontist with ample expertise in this field.

Results:
Survival rate after 1 year was 98%, success rate was 95.6%. Autotransplantation of a tooth in a young and growing child is considered successful if the transplanted tooth performs like a normal premolar: revitalization of the pulp with pulp chamber and later pulp canal obliteration, survival of the periodontal ligament with no progressive external root resorption. Eruption during growth must be spontaneous and the orthodontist should be able to rotate the tooth. The costs of 1 premolar transplantation by the OMF-surgeon during 3 visits including radiographs and surgical treatment are a little less than Euro 1000. (2018).
12.15-12.30Tooth autotransplantations in the anterior mandible and maxilla
M. Gilijamse, J.A. Baart, M. de Cleen, Tj. Swart
Department of Oral and Maxillofacial Surgery and Oral Pathology, University Hospital Vrije Universiteit Amsterdam/ACTA, Amsterdam, the Netherlands

Introduction:
This retrospective study evaluates the survival rates, prognosis, and overall success of autotransplanted teeth in young patients with missing anterior teeth due to trauma, agenesis, or developmental disturbances.

Material and Methods:
Retrospective data was collected from the medical records of patients who where treated by tooth autotransplantation at the Department of Oral and Maxillofacial Surgery and Oral Pathology at the University Hospital Vrije Universiteit Amsterdam. Clinical variables such as gender, age, surgical indications, recipient and donor sites, type of anaesthetics, bone augmentation, and complications during follow-up were registered for analysis.

Results and Conclusions:
Fifty-nine donor teeth in 46 patients (30 boys/16 girls) with an average age of 12,15 years were autotransplanted to the anterior region. After a mean follow-up period of 17,35 months (ranging from 1 to 61 months), survival of autotransplanted teeth was 100%. Despite some limitations, this study supports the conclusion that tooth autotransplantation to the anterior region is an excellent treatment option for suitable patients with missing anterior teeth due to trauma, aplasia, or developmental disturbances.

Key words: autotransplantation, front region, success rate, complications
12.30-12.45Primary tooth auto-transplantation for instant rehabilitation of young children with traumatic loss or agenesis of permanent incisors
Claudia Tschammler1, Robert Linsenmann2, Dirk Nolte2,3
1. Department of Preventive Dentistry, Periodontology and Cariology, University Medical Center
Göttingen, Germany
2. Dental Clinic of OMF-Surgery, Sauerbruchstr. 48, D-81377 Munich -Großhadern
3. Faculty of Medicine, Ruhr University of Bochum, Germany

Introduction:
Avulsion and loss or agenesis of the upper central incisors in young patients (age 7 to 13) are a big challenge for dentists and oral surgeons since both vertical and horizontal deficit of jaw growth may occur. Therefore, the focus of therapy should aim at the promotion and the support of the natural growth of the jaw as early as possible after onset of traumatic tooth loss or agene-sis.

Objectives:
The aim of the study was to investigate the effects of primary tooth autotransplantation on soft tissue and bone growth after traumatic loss or agenesis of the upper central or lateral incisors.

Material and Methods:
A total of 10 patients (age range, 7-13 years) were treated either for trauma or agenesis (n = 14 primary canine transplants). In addition to the clinical examination, patients were subjected to radiologic examinations with regard to root resorption, bone height, and soft tissue level.

Results:
With an average survival rate of 87%, the average survival time of the transplants was 5.2 years. The longest survival time of a transplant was 11 years. The morbidity of the young pa-tients was low as reflected by the high satisfaction of patients and parents with a mean overall score of 1.5 (score: 1 = very good, 6 = very low). In all cases, soft tissue and bone growth was effectively developed. Transplant ankylosis associated with vertical growth inhibition was not observed.

Conclusions:
Primary tooth auto-transplantation is a reliable surgical method for quick rehabilitation of chil-dren in early mixed dentition, enabling adequate soft tissue and bone growth.
12.45-13.00Is autotransplantation a reliable treatment option?
K.J.H. van Westerveld1; J.P. Verweij1; D. Anssari Moin2; G. Mensink1,3; J.P.R. van Merkesteyn1
1. Leiden University Medical Center (LUMC), Leiden, the Netherlands
2. Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, the Netherlands
3. Amphia hospital, Breda, the Netherlands

Objectives:
This retrospective cohort study investigated the short-term success and long-term survival of autotransplanted premolars and molars with incomplete root development.

Material and Methods:
The medical files and radiographs of consecutive patients, that were treated between 1996 and 2015 were analysed. A questionnaire regarding the presence of transplanted teeth was sent to the patient. The patients’ dentists were also sent an additional questionnaire, based on the clinical examination and radiographic examination by the dentist.

Results and Conclusions:
The short-term outcome after autotransplantation shows 82% success rate. The other 18% of transplants (‘unsuccessful cases’) were successfully treated, for example with an endodontic treatment. All transplanted teeth functioned well one year after transplantation, even if an additional procedure was necessary.
The long-term median follow-up with questionnaires was 10.5 years, a total of 68 patient (89 transplants) responded. Six out of 78 premolars (7.7%) and two out of 11 molars (18.2%) were removed. The cumulative 10-year survival rate was computed for 89 autotransplanted teeth and was 90.1%.
This shows that autotransplantation can be considered a good treatment option for permanent single-tooth replacement. These findings may play an important role when choosing between autotransplantation and alternative therapies in young patients.
13.00-13.15A long-term evaluation of the success of 144 tooth autotransplants
Pinheiro T.N.1, Roldi A.2, Intra J.B.G.2, Nunes F.C.3
1. Department of Oral and Maxilofacial Pathology, Amazonas State University, Amazonas
2. Department of Endodontics, Federal University of Espırito Santo, Espırito Santo, Brazil
3. Sao Leopoldo Mandic College, Campinas, Brazil

Introduction:
Among the possible treatments available in oral rehabilitation of a patient, dental autotransplantation is an important procedure in the replacement of missing and lost teeth.

Aim:
The present study examined a sample of 144 teeth autotransplants performed in 128 patients, which were subjected to periodic follow-up from 6 months to 23 years. The objective was to evaluate the success rate of the transplants.

Material and methods:
The sample comprised 33 molars, 91 premolars, 4 canines and 16 incisors. The patients were submitted to periodical clinical and radiographic examination every 6 month since the day of transplantation. The success rate was calculated based on the percentage of transplanted teeth that presented a good functional status during follow-up. In the last follow-up visit, successful autotransplantation should present: absence of active root resorption and ankylosis; crown/root ratio less than 1 (root size higher than crown size); radiographic evidence of additional root growth (in case of partly formed root grafts); and absence of tooth mobility, periodontal disease, and persistent periapical lesions after endodontic treatment. The success rate was acquired by the percentage of transplanted teeth that met the criteria in relation to the total number of transplanted teeth in the sample.

Results and conclusions:
The evaluation showed a 93% success rate for completion of autotransplanted tooth. These findings support that tooth autotransplantation is a reliable treatment option to tooth loss. Tooth autotransplantation is a viable procedure with low morbidity.
13.15-13.30The patient’s perspective and the survival rate of tooth transplantation
Jessica Juslin, DDS Päivi Jääsaari, DDS PhD, Tuija Teerijoki-Oksa, University of Turku, Turku University Hospital, Finland

Introduction:
Autotransplantation of teeth is an alternative treatment method in young patients suffering from hypodontia or impacted teeth.

Objectives:
The aim of this work was to investigate the survival of tooth transplants at Turku University Hospital. Patient views were evaluated by questionnaire.

Material and Methods:
The sample consisted of 36 patients (24 female, 12 male) treated during a time period between 10/2009 and 01/2017. 36 out of 37 patients that underwent tooth transplantation answered the survey and gave permission to analyse their patient files. Patient age ranged from 9,8 to 22,9 years (mean 14,4 years). The follow-up time ranged from 1,3 months to 6,9 years (mean 2,14 years). Demirjian et al method was used to determine the developmental stage of the root E, F or G (in 6, 31 or 8 cases, respectively). The Fisher Exact test was used to analyse the data.

Results and Conclusions:
The overall survival rate of the 45 transplanted teeth was 82 %. In successful transplantations continued root formation was observed in follow-up x-rays compared to unsuccessful transplants (p=0.0013). Neither the stage of root formation (p=0.51) nor the number of roots (22 one-rooted, 23 two-rooted) affected the survival of transplants (p=0.24). Difficulties were detected in 13 cases during surgery including trauma on the periodontal ligament, problems positioning the donor tooth or change of treatment plan. These difficulties did not affect survival (p= 0.59). Patients reported that they received enough information before and after the transplantation. Patients were satisfied with the current position of the transplanted tooth.

Tooth transplantation is a valuable treatment option in growing patients. Patients were satisfied with the received treatment.
13.30-13.45Complications and endodontic treatment after autotransplantation of premolars: a retrospective study
Michiel J.H. de Cleen (Practice limited tot endodontics, Amsterdam, the Netherlands), Jacques A. Baart (Dept. of Oral and Maxillofacial Surgery, VU Medical Center, Amsterdam, the Netherlands)

Introduction:
Successful autotransplantation of immature teeth results in periodontal healing, obliteration of the pulp space and continued root growth. If pulpal healing does not occur, apical periodontitis may develop. In these cases endodontic treatment (e.g. apexification) is indicated.

Material and Methods:
In this retrospective study, the results of endodontic treatment of 25 autotransplanted premolars were evaluated. All transplantations were performed by the second author (JAB). All endodontic treatments were carried out by the first author (MJHdC) between 2009 and 2017. Periapical radiographs taken at the start and completion of endodontic treatment and 1-3 years post-operatively were used to evaluate the treatment results. The outcomes of endodontic treatment were classified as complete healing (healed), incomplete healing or non-healing.

Results:
Eight teeth were not available for evaluation; 17 teeth were evaluated 1-3 years after endodontic treatment. Complete healing after endodontic treatment was observed in 88% of the teeth one year after treatment and in 94% of the teeth two years after treatment. In some cases, continued root growth was observed after completion of the endodontic treatment.

Conclusion:
In cases of apical periodontitis after autotransplantation of immature premolars, endodontic treatment is very successful.

Key words: autotransplantation, endodontics, apexification
13.45-13.55Orthodontic forces and their sequelae on autotransplanted teeth: A literature overview.
Jordan B.1, Nolte D.2, Müßig D.3
1. Praxis Dr. Jordan, Neumarkt, Germany
2. MD DDS PhD, Dental Praxis of OMF-Surgery, Munich, Germany
3. Univ.-Prof. Dr. Dr. D. Müßig, Danube Private University (DPU), Krems, Austria

Introduction:
Autotransplantation of teeth is a biological therapy to substitute missing teeth. Thereby, it may act as an interface between conventional dental medicine, oral surgery and orthodontics. So far, little is known about the movement of the tooth transplant in regard of application of the ideal orthodontic force and its best timing of onset.

Objectives:
It was the aim of this study to give an overview of the literature with respect to the influence of the orthodontic forces applied and their sequelae for the healing process of the transplant.

Material and Methods:
A literature search was conducted in three databases and eligibility criteria were established. The searches identified 10.069 articles and after evaluation of exclusion criteria, seven could be included. After extraction of clinical contents from the articles, they are reported narratively.

Results:
The major findings are summarized as follows: 1) Pre- and post-surgery application of adequate force has a positive influence on healing of the transplant. 2) Orthodontic treatment should be performed as soon as possible post-surgery after an initial period of rest ranging between two to about twelve weeks. 3) Loading of the transplant should be performed with light orthodontic forces. 4) Derotation of multi-rooted teeth leads to an increased risk for pulpal or periodontal complications and a shorter final root length. 5) Orthodontic extrusion, minor lateral movement or derotation of single-rooted transplants have no negative influence on outcome.

Conclusion:
Obeying the above given recommendations of pre- and post-surgery transplant handling may improve the healing process and thereby the long-term outcome of the transplants.

Keywords: autotransplantation, orthodontics, force.
13.55-14.05Enhancement of human periodontal ligament by pre-application of orthodontic loading
Kittitat Nakdilok1, Suttichai Krisanaprakornkit2, Eduardo Yugo Suzuki1, Boonsiva Suzuki1
1. Faculty of Dentistry, Bangkokthonburi University, Bangkok 10170, Thailand
2. Center of Excellence in Oral and Maxillofacial Biology, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200, Thailand

Introduction:
The quantity of remaining periodontal ligament (PDL) on the root surface of donor teeth is essential for success of tooth autotransplantation. Pre-application of orthodontic force on the rat teeth increased PDL on the root surface. However, little is known about the effect of preloading on human PDL and its optimal duration.

Objectives:
To determine the optimal duration of orthodontic preloading for maximal PDL tissue on the root surface of extracted human premolars and for facilitating extraction.

Material and Methods:
Twenty-six patients, requiring premolar extraction for orthodontics, received orthodontic loading on either side of their first premolar for 4, 6 or 8 weeks, whereas the contralateral first premolar was not loaded as a control. The loading comprised brackets bonded on either maxillary or mandibular first premolars and 0.016-inch nickel-titanium archwires tied with elastomeric rings. After loading, extractions were performed by the same surgeon with a record for duration of the extraction procedure. The difficulty of extraction was assessed by the surgeon. The extracted premolars were stained with toluidine blue to measure the percentage of residual PDL tissue.

Results and Conclusions:
The results showed that orthodontic preloading for 4 weeks, but not 6 or 8, significantly increased the percentage of stained PDL on the root surface compared to the control (P<0.05). The duration and the difficulty of extraction were significantly less in loaded than unloaded teeth at 4 weeks (P<0.05). Collectively, the 4-week duration of orthodontic preloading was shown to increase PDL and ease tooth extraction, which may be beneficial for tooth autotransplantation.

Keywords: Orthodontic preloading; Periodontal ligament; Premolar; Tooth autotransplantation
Support from the Thailand Research Fund (BRG6080001) to S.K. is gratefully acknowledged.
14.05-14.15Altered expression of pluripotent markers in human periodontal ligament upon application of orthodontic preloading
Sasathorn Phutinart1, Boonsiva Suzuki1, Eduardo Yugo Suzuki1, Suttichai Krisanaprakornkit2
1. Faculty of Dentistry, Bangkokthonburi University, Bangkok 10170, Thailand
2. Center of Excellence in Oral and Maxillofacial Biology, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200, Thailand

Introduction:
Successful tooth autotransplantation requires preservation of vital periodontal ligament (PDL) cells. Previous studies have demonstrated effect of orthodontic preloading on PDL remaining on the root surface and on the easy extraction of donor teeth. However, the effect of preloading on expression of pluripotent markers, including NANOG and Oct4 whose expression was up-regulated by treatment with prostaglandin E2 in cultured human PDL cells, has not yet been investigated.

Objective:
To determine and monitor expression of NANOG and Oct4 proteins in PDL tissue upon an application of preloading force for different periods of time.

Material and Methods:
Ten patients, requiring extraction of four first premolars for their orthodontic treatment, were recruited with informed consent. Premolars in the experimental groups were subjected to light leveling orthodontic force for one, two or four weeks, whereas those in the control group received no force application. All teeth were extracted using a forceps technique, and total protein was freshly isolated from PDL tissue, scraped off using a scalpel below the cervical one-third of the root, by a glass homogenizer. The expression of NANOG and Oct4, normalized by that of beta-actin, was analyzed by immunoblotting, and the relative ratios of expressions were compared between groups.

Results and Conclusions:
Varying expressions of NANOG and Oct4 were detected at their predicted sizes in both control and experimental groups. The expression levels were clearly up-regulated after preloading at any time points, reflecting an increase in the number of PDL stem cells that may help improve success rate of autotransplantation.

Keywords: NANOG; Oct4; Orthodontic loading; Periodontal ligament; Stem cell
Support from the Thailand Research Fund (BRG6080001) to S.K. is gratefully acknowledged.
14.15-14.25 Periodontal ligament preservation during orthodontic tooth movement in human
Promchaiwattana P, Suzuki B, Suzuki EY, Krisanaprakornkit S, Thailand
Pattarin Promchaiwattana1, Boonsiva Suzuki1, Eduardo Yugo Suzuki1, Suttichai Krisanaprakornkit2
1. Faculty of Dentistry, Bangkokthonburi University, Bangkok 10170, Thailand
2. Center of Excellence in Oral and Maxillofacial Biology, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200, Thailand

Introduction:
The preservation of vital periodontal ligament (PDL) cells and good PDL tissue adaptation are the most important considerations for successful tooth autotransplantation (TAT). Preloading with orthodontic force before extraction eases the extraction and results in rich PDL tissue on the root surface of the rat teeth. However, the effect of orthodontic preloading on the preservation of human PDL tissue has never been investigated.

Objectives:
To examine the amount of remaining PDL tissue on the root surface of extracted third molars following pre-application of orthodontic force.

Material and Methods:
Twelve partially erupted third molars with mesio-angulation, extracted before orthodontic treatment, were included. The experimental molars (n=6) received orthodontic force using a Smart Spring connected to a single miniscrew anchorage as a means of orthodontic extraction, while the contralateral mesio-angular impacted third molars (n=6) received no force application as a control. Alterations in angulation and position of the third molars were monitored by panoramic radiographs. The extracted teeth were stained with toluidine blue to determine the amount of remaining PDL on the root surface under stereomicroscopy. The percentages of stained PDL areas were then compared between experimental and control groups.

Results and Conclusions:
After preloading force for three months, the angulation of experimental third molars was decreased to half of that before preloading force. Moreover, the mean percentage of remaining PDL tissue on preloaded teeth was significantly higher than that on unloaded teeth (P<0.05), indicating that orthodontic preloading increases the amounts of PDL tissue, which may influence the success of TAT.

Keywords: Orthodontic force; Periodontal ligament; Transplantation; Miniscrew implants
14.25-14.35Discussion
14.35-15.00Coffee break
II Scientific Session
Session Chairmen: Manfred Leunisse, Paweł Plakwicz
15.00-15.15How can we minimize the risk of External Cervical Resorption during autotransplantation?
A.M. Mavridou1,2, E. Eggink2, M. Linssen2, D. Barendregt2, P. Lambrechts1
1. Department of Oral Health Sciences, BIOMAT Research Cluster, KU Leuven & University Hospitals Leuven, Leuven, Belgium
2. Private practice, Proclin Rotterdam, Rotterdam, the Netherlands

Aim:
To investigate under which conditions autotransplantation can potentially result in External Cervical Resorption. A focus is also given on how to minimize the risk of ECR by preventing PDL damage and hypoxia during autotransplantation.

Material and Methods:
In this study five indicative cases of ECR after autotransplantation were included. To identify the potential predisposing factors the medical history, existing radiographs, and dental records were evaluated. Intraoral pictures using a dental operating microscope and digital camera were taken during clinical examination. The radiographic examination consisted of digital periapical radiography and/or cone-beam computed tomographic imaging.
The 3D patterns of these different clinical cases were assessed with CBCT (Morita, FOV 40x40, 60x60), and with a high performance NanoTom scanner (GE Measurement and Control Solutions, Wunstorf, Germany). To verify the types of cell tissues involved, additional histological analysis was performed.
Clinical case examples were presented to illustrate the potential predisposing factors involved and evolution mechanism.

Results:
It was found that autotransplantation can be only linked to ECR under very specific and limited conditions. This is because it can result in the damage of PDL and cementum, but for ECR to occur there also needs to be an additional stimulating factor that creates a hypoxic microenvironment (e.g. plague, orthodontics etc.). Indeed, oxygen tension is found to: (a) regulate the osteoclast and osteoblast biology (formation and activation of osteoclasts and osteoblasts) and (b) hinder the recovery of human PDL fibroblasts. In any case the pattern of ECR remains the same, as the 3 stages namely initiation, resorption and repair/remodeling were observed.
In addition, the risk of ECR during autotransplantation can be minimized by using less aggressive techniques (e.g. rotational force during extraction instead of axial) so that the PDL remains intact, and the extraction forceps should not be in contact with the cervical part of the tooth. It should be also noted that the clinician should also consider that poor oral health and orthodontics (e.g. timing, type of forces) may influence the outcome/success of autotransplantation process.

Conculsions:
There is a low risk of ECR during autotrasplantation, as it can only act as a synergetic potential predisposing factor for ECR occurrence. This risk can be further decreased by preparing a correct treatment planning that involves less aggressive techniques and takes into consideration additional predisposing factors that could influence the outcome/success of autotransplantation process.
15.15-15.25A case of tooth autotransplantation for severe atrophic alveolar combined with orthodontic treatment, bone augmentation and vestibuloplasty
Yusuke Matsuzawa1, Yuna Abe2, Kanchu Tei3, Tetsuro Yamashita4
1. Department of Oral and Maxillofacial Surgery, Keiyukai Sapporo Hospital, Sapporo
2. Department of Oral Surgery, JR Sapporo Hospital Department of Oral and Maxillofacial Surgery, Division of Oral Patho-biological Science, Hokkaido University Faculty of Dental Medicine
3. Department of Oral and Maxillofacial Surgery, Division of Oral Patho-biological Science, Hokkaido University Faculty of Dental Medicine
4. Department of Oral and Maxillofacial Surgery, Keiyukai Sapporo Hospital, Japan

Introduction:
In order to achieve the ideal transplantation, it is important that the alveolus width of the recipient site suitable for the root of donor tooth are maintained, and that the keratinized gingiva is present.

Objectives:
The object of this report is to introduce a case of tooth autotransplantation for severe atrophic alveolar combined with orthodontic treatment, bone augmentation and vestibuloplasty.

Case presentation:
A 41-year-old woman was consulted to transplant teeth from an orthodontist. The lower right first and second molar were absent, but third molar was existed. The alveolus width was narrow, the oral vestibule was shallow and the keratinized gingiva was defective.I contrive a treatment plan to transplant the upper left first premolar requiring tooth extraction in orthodontic treatment to the right lower first molar site, but I decided to perform bone augmentation and vestibuloplasty. I performed bone augumentation by veneer grafting with chin bon. Six month after bone grafting, I performed vestibuloplasty by graft of palatal mucosa. One year 6 months after bone grafting, tooth autotransplant was undergone. During the follow-up observation, the tooth root of the right lower third molar fracture, so I transplanted the right upper third molar.

Result and Conclusions:
At the time of about 10 years from the first transplantation, 6 years after the second transplantation, Orthodontic treatment is also finished, and good occlusion has been obtained. The transplanted keratinized gingiva is maintained, the pocket depth of the transplanted tooth is within 3 mm, the tooth mobility is M 0, and percussion pain is not seen. On the X-ray, both of the transplanted teeth have a clear periodontal ligament space and lamina alba and root resorption was not observed.
15.25-15.35Autotransplantation of a lower cuspid - case presentation
Manuela Daian, Anna Louropoulou, Michalis Pantaleon, Practice Orthodontie, Oud-Beijerland, Clinic ParoRotterdam, Rotterdam, the Netherlands

Introduction
Mandibular canine impaction with or without transmigration is regarded as a much rarer phenomenon and there are limited studies revealing its frequency of occurrence.
Canine impactions occur 20 times more frequently in the maxilla than in the mandible and impacted maxillary canines have not been observed migrating across the midline palatal suture.
The cause is usually a supernumerary tooth, an odontoma or crowding. It may, however, occur with no apparent reason.

Objectives
This problem has several solutions. The tooth could be surgically exposed and moved into the dental arch orthodontically, an autotransplantation could be performed or the cuspid can be extracted.

Case presentation
We will present in detail a case of a 13-year old girl with an impacted and transmigrated lower cuspid. The autotransplantation was chosen as the treatment method. The autotrasplantation was performed in the Clinic ParoRotterdam. Because the root formation of the cuspid was complete an endodontic treatment was performed two weeks after the autotransplantation.
The postoperative phase developed without complications and the orthodontic treatment was completed within 11 months after the autotransplantation.

Conclusions
In 1933 Harry Wright stated that in order to have a normal occlusion all the permanent teeth shall be present and in a correct position. Referring to the impacted teeth and their treatment he affirmed that: “is easier to extract such a tooth than to aid his eruption”. Unfortunately, his affirmations are still present; there are still clinicians who choose for extraction of the lower impacted cuspid even if the position of the cuspid allows the autotransplantation.
15.35-15.45Exploring the limits of tooth autotransplantation
Jan Streblov, 3DK Dental Clinic, Prague, Czech Republic

Tooth autotransplantation becomes increasingly popular and new indications have been sought during last years. One of the keystone questions is, what amount of bone is necessary for tooth transplantation?
In contrast to dental implants, there are no strict rules prescribing the width of the bone when transplanting a tooth. Moreover, teeth are usually much wider than implants, so when thinking analogically to dental implants, much more bone would be needed for a tooth transplantation. However, such way of thinking seems to be inappropriate.
The presentation will deal with situations, where bone volume seems to be insufficient or extremely limited. Is there a way, how to transplant teeth anyway? Do we need some bone augmentation materials? Several case reports with a follow up 2 - 6 years will be presented and a biologic principle will be explained.
15.45-15.55Case report of tooth transplantations in patients over 50 years old
Koichi Yoshino
Department of Epidemiology and Public Health, Tokyo Dental College, Japan

Recently, tooth transplantation (TT) is often used for young patients for achieving ideal tooth dentition. For older adults, one of purpose of TT is maintaining tooth alignment. However, one of the risk factors of TT is age. Previous literature has revealed that using donor teeth with complete root formation is a risk factor for complications. This case report presents cases of TT in patients over 50 years old using donor teeth with complete root formation. I present six cases, including five males (51, 57 (2), 60, and 65 years) and one female (61 years) who received TT at my dental clinic. Donor teeth were two lower third molars, one upper third molar, one upper and one lower second molar, and one upper lateral incisor. Recipient sites included two in the lower first molar position, two in the upper first molar position, and one each in the lower second molar and upper second premolar positions. Five of the cases were single root transplantations and one was a triple root transplantation. The observation periods were from 5 to 9 years. All cases demonstrate clinical survival of the transplanted tooth. In Japan, TT can often be provided at a lower cost to the patient than implants, as national health insurance covers transplantation of third molars. If suitable donor teeth are available, TT is a plausible treatment option for replacing missing teeth, for the purpose of maintaining tooth alignment.
15.55-16.05Tooth transplantation: where are the limits?
Novosad M, Marek I, Private Dental Clinic STOMMA Breclav, Czech Republic

Tooth autotransplantation is one of the methods to replace a missing tooth, with a long-term prognosis and no need to insert a non-biological material into the body.
However, where are the limits? When is it better to use an implant? When is it too risky to use an autotransplant? The authors reflect indication and surgical limits of autotransplantation, the complications and their possible solutions.
16.05-16.20Three-dimensional imaging and rapid prototyping in autotransplantation: innovation that excites!
J.P.R van Merkesteyn1; J.P. Verweij1; K.J.H. van Westerveld1; D. Anssari Moin2; G. Mensink1,3
1. Leiden University Medical Center (LUMC), Leiden, the Netherlands
2. Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, the Netherlands
3. Amphia hospital, Breda, the Netherlands

Introduction:
Autotransplantation of premolars is a good treatment option for single-tooth replacement. Nevertheless, surgeons should always strive to improve the predictability of the procedure and minimize discomfort for the patient.

Objectives:
This prospective study aimed to evaluate the benefits and outcome of autotransplantation of premolars with the help of three-dimensional (3D) imaging and rapid prototyping techniques.

Material and Methods:
In a prospective observational study design, all ‘3D autotransplantation’ procedures of premolars that were performed since 2015 are analysed. All autotransplantation procedures were performed with a patient specific replica of the donor tooth, based on a pre-operative cone-beam computed tomogram (CBCT). Intra-operatively, the extra-alveolar time of the transplant, the number of fitting attempts with the transplant and the procedural time were recorded. Post-operatively, the healing after autotransplantation was monitored and possible adverse events, such as root resorption, ankylosis or endodontic problems were also recorded.

Results and Conclusions:
Our first experiences show that 3D autotransplantation enables a quick and easy procedure. The extra-alveolar time is less than one minute in almost every case with 1 or 2 fitting attempts to achieve a good fit of the transplant.
16.20-16.35Three-dimensional imaging and rapid prototyping in autotransplantation: the (im)possibilities of a technique
J.P. Verweij1; K.J.H. van Westerveld1; D. Anssari Moin2; G. Mensink1,3; J.P.R. van Merkesteyn1
1. Leiden University Medical Center (LUMC), Leiden, the Netherlands
2. Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, the Netherlands
3. Amphia hospital, Breda, the Netherlands

Introduction:
Current advances in three-dimensional (3D) imaging have transformed modern day dentistry and oral surgery. The new imaging modalities and rise of rapid prototyping shows a promise of new possibilities in many different fields, including the field of tooth transplantation.

Objectives:
This study aimed to investigate the possibilities (and limits of the possibilities) of autotransplantation with the help of three-dimensional imaging and rapid prototyping.

Material and Methods:
All autotransplantation procedures were performed with a patient specific replica of the donor tooth, based on a pre-operative 3D imaging and rapid prototyping. Several difficult autotransplantation procedures were analysed. These procedures included transplantation of impacted canines; transplantation to the site of a fracture after mandibular fractures combined with loss of teeth; transplantation of curved/malformed third molars; transplantation of multiple third molars to replace heavily damaged/infectious molars etc.

Results and Conclusions:
In our experience, ‘3D autotransplantation’ has shown to be very valuable in order to make challenging cases possible. However, in some cases successful autotransplantation of teeth remains a challenge. It is therefore important to share and analyse the limits of the possibilities of the 3D autotransplantation technique.
16.35-16.50CBCT-based tooth autotransplantation – Part I: 3D planning, 3D printing and 3D analysis of treatment outcome.
Mostafa EzEldeen1,2, Jan Wyatt2, Andreas Stratis1, Reinhilde Jacobs1
1. OMFS IMPATH Research Group, Faculty of Medicine, Department of Imaging and Pathology, KU Leuven and Oral and Maxillofacial Surgery
2. Department of Oral Health Sciences, KU Leuven and Paediatric Dentistry and Special Dental Care, University Hospitals Leuven, Leuven

Introduction:
Tooth autotransplantation (TAT) offers a viable biological approach to tooth replacement in children. To enhance the outcome predictability of the TAT procedure, a cone-beam computed tomographic (CBCT)- based surgical planning and transfer technique has been developed.

Objectives:
To optimize the CBCT scanning protocol to achieve a dose as low as possible and to maintain sufficient image quality for tooth autotransplantation planning and follow-up, to evaluate the patterns of healing after transplantation.

Material and Methods:
Eighteen exposure protocols in 3 different CBCT machines were evaluated. Effective dose (ED) was calculated using Monte-Carlo simulation and pediatric voxel phantoms (5 & 8 years-old male, 12 years-old female). Image quality was assessed by: comparing segmented teeth volumes, evaluation of the visibility of lamina-dura, and morphological surface analysis of 3D models. A general linear mixed model was fit to combine image quality parameters and radiation effective dose for each protocol in order to rank and compare all the protocols examined in the study. Pre and post-operative CBCT images (n= 44, follow-up period = 1-10 years) were analyzed using a novel method analyzing the 3D hard tissue change of the transplanted teeth.

Results and Conclusion:
The ED for the pre-operative scan can be reduced to the range of 74.6-157.9 µSv. ED for the post-operative scan can be reduced to the range of 24.2-41.5 µSv. CBCT-based volumetric comparison of the root hard tissue (Pre vs. Post) showed beneficial hard tissue formation. A considerable reduction in the pediatric effective dose can be achieved while maintaining sufficient image quality for tooth auto-transplantation planning and follow-up using elaborated dose optimization protocols.

Keywords: CBCT, Tooth Autotransplantation, 3D planning, 3D printing
16.50-17.00CBCT-based tooth autotransplantation – Part II: Surgical technique, follow-up, short and long-term treatment outcome.
Wyatt J, EzEldeen M, Shahbazian M, Jacobs R, Belgium
Jan Wyatt1, Mostafa EzEldeen1,2, Maryam Shahbazian2, Reinhilde Jacobs2
1. Department of Oral Health Sciences, KU Leuven and Paediatric Dentistry and Special Dental Care, University Hospitals Leuven, Leuven
2. OMFS IMPATH Research Group, Faculty of Medicine, Department of Imaging and Pathology, KU Leuven and Oral and Maxillofacial Surgery

Introduction:
Tooth autotransplantation (TAT) offers a viable biological approach to tooth replacement in children. To enhance the outcome predictability of the TAT procedure, a cone-beam computed tomographic (CBCT)- based surgical planning and transfer technique has been developed.

Objectives:
To evaluate the outcome of CBCT-based autotransplantation technique. To compare the outcome of CBCT-based surgical planning and transfer technique for tooth autotransplantation versus conventional autotransplantation.

Material and Methods:
Total of 44 pediatric patients received CBCT-based TAT in the period between 2007-2016. For the comparative study a total of 40 subjects in whom 48 teeth were included following a case control design. The study group (n= 20, mean age 11 years) underwent CBCT imaging for surgical planning and transfer via stereolithographic tooth replica fabrication, the historical control group (n= 20, mean age 12 years) was subjected to conventional autotransplantation.

Results and Conclusion:
The group underwent CBCT-based TAT showed overall a 91% survival rate and 89% success rate after and average follow-up period of 4.5 years. The CBCT-based preoperative planning and the use of a tooth replica decreased the extra-alveolar time and reduced the number of positioning trials with the donor tooth. In the control group (case-control study), 6 patients showed 1 or more complications, while this was noticed for only 2 patients in the CBCT-based group.
Patients with CBCT-based surgical planning of tooth autotransplantation may benefit from a shorter surgical time, a less invasive technique, and fewer failures than a conventional approach.

Keywords: CBCT, Tooth Autotransplantation, Surgical technique, Clinical outcome
17.00-17.20Affordable 3D planning for tooth transplantation in all stages of development
van der Meer J1, Barendregt D.2
1. University Medical Center Groningen
2. Proclin Rotterdam, Netherlands

The planning of tooth transplantation is often complex and requires the joint effort of a multi-disciplinary team to accomplish the desired end-result. Digital technology and 3D workflows seem to be a portent of radical changes in the dental profession and this technological shift should lead to highly reliable treatment results with an unsurpassed quality. The digital technology could offer new and exciting possibilities for these complex cases, like tooth transplantation. But the different applications seem scarcely available and quite often only appeal to the 3D cognoscenti.
In our team, we’ve been able to integrate digital planning of the tooth transplantation cases that involve the loss of multiple front teeth. The digital workflow offers a wide range of solutions that can be combined and used not only for the planning of the different treatment phases, but also to facilitate the communication within the team and between the team members. By employing cone beam CT, intra and extra oral scanners and free software planning tools, we’re able to plan our complex cases in all of the phases. Low cost 3D printers are often used to produce the tools necessary to facilitate the different treatments.
In this lecture, an overview is given of the workflow that can be used in any inter-disciplinary dental trauma team and the tools made in medical-grade polymethylmethacrylaat, that are readily available for this, are explained. Clinical examples are shown to illustrate the different phases of the digital workflow and the end-results that can be accomplished in this way.
17.20-17.30Discussion