AUTOGENOUS TOOTH TRANSPLANTATION AS AN ALTERNATIVE TREATMENT FOR PATIENTS WITH MISSING TEETH : A SYSTEMATIC REVIEW

Transcription

1 Christopher Antoine Germany OF 5, 13 group AUTOGENOUS TOOTH TRANSPLANTATION AS AN ALTERNATIVE TREATMENT FOR PATIENTS WITH MISSING TEETH : A SYSTEMATIC REVIEW Master s Thesis Dr. Arunas Vasiliauskas PhD, Arunas Vasiliauskas Kaunas,

2 LITHUANIAN UNIVERSITY OF HEALTH SCIENCES MEDICAL ACADEMY FACULTY OF ODONTOLOGY CLINIC OF ORTHODONTICS AUTOGENOUS TEETH TRANSPLANTATION AS AN ALTERNATIVE TREATMENT IN PATIENTS WITH MISSING TEETH Master s Thesis The thesis was done by student Christopher Antoine Germany (signature) Supervisor Dr.Arunas Vasiliauskas (signature) (namesurname,year,group) (degree, name surname) (day/month) (day/month) Kaunas,

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4 EVALUATION TABLE OF THE MASTER S THESIS OF THE TYPE OF SYSTEMIC REVIEW OF SCIENTIFIC LITERATURE Evaluation:... Reviewer:... (scientific degree. name and surname) Compliance with MT No. MT parts MT evaluation aspects requirements and evaluation Yes Partially No Is summary informative and in compliance with the thesis 1 Summary ( content and requirements? point) 2 Are keywords in compliance with the thesis essence? Are the novelty, relevance and significance of the work Introduc-tion, justified in the introduction of the thesis? aim and tasks Are the problem, hypothesis, aim and tasks formed (1 point) clearly and properly? Are the aim and tasks interrelated? Is the protocol of systemic review present? Were the eligibility criteria of articles for the selected 7 protocol determined (e.g., year, language, publication condition, etc.) Are all the information sources (databases with dates of Selection 8 coverage, contact with study authors to identify additional criteria of the studies) described and is the last search day indicated? studies, Is the electronic search strategy described in such a way search that it could be repeated (year of search, the last search methods and 9 day; keywords and their combinations; number of found strategy and selected articles according to the combinations of (3.4 points) keywords)? Is the selection process of studies (screening, eligibility, 10 included in systemic review or, if applicable, included in the meta-analysis) described? 11 Is the data extraction method from the articles (types of

5 investigations, participants, interventions, analysed factors, indexes) described? 12 Are all the variables (for which data were sought and any assumptions and simplifications made) listed and defined? 13 Are the methods, which were used to evaluate the risk of bias of individual studies and how this information is to be used in data synthesis, described? 14 Were the principal summary measures (risk ratio, difference in means) stated? Is the number of studies screened: included upon assessment for eligibility and excluded upon giving the reasons in each stage of exclusion presented? 16 Are the characteristics of studies presented in the included Systemization and study size, follow-up period, type of respondents) articles, according to which the data were extracted (e.g., analysis of data presented? Are the evaluations of beneficial or harmful outcomes for 17 (2.2 points) each study presented? (a) simple summary data for each intervention group; b) effect estimates and confidence intervals) 18 Are the extracted and systemized data from studies presented in the tables according to individual tasks? Are the main findings summarized and is their relevance indicated? Discussion Are the limitations of the performed systemic review 20 (1.4 points) discussed? 21 Does author present the interpretation of the results? Do the conclusions reflect the topic, aim and tasks of the Conclusions Master s thesis? (0.5 points) Are the conclusions based on the analysed material? Are the conclusions clear and laconic? Is the references list formed according to the requirements? References Are the links of the references to the text correct? Are the 26 (1 point) literature sources cited correctly and precisely? 27 Is the scientific level of references suitable for Master s

6 thesis? 28 Do the cited sources not older than 10 years old form at least 70% of sources, and the not older than 5 years at least 40%? Additional sections, which may increase the collected number of points 29 Annexes Do the presented annexes help to understand the analysed topic? Practical Are the practical recommendations suggested and are recommendations they related to the received results? Were additional methods of data analysis and their results 31 used and described (sensitivity analyses, metaregression)? Was meta-analysis applied? Are the selected statistical methods indicated? Are the results of each meta-analysis presented? General requirements, non-compliance with which reduce the number of points 33 Is the thesis volume sufficient (excluding pages <15 pages annexes)? (-2 points) (-5 points) 34 Is the thesis volume increased artificially? -2 points -1 point General 38 require-ments Does the thesis structure satisfy the requirements of Master s thesis? -1 point -2 points Is the thesis written in correct language, scientifically, logically and laconically? -0.5 point -1 points Are there any grammatical, style or computer literacy-related mistakes? -2 points -1 points Is text consistent, integral, and are the volumes of its structural parts balanced? -0.2 point -0.5 points 39 Amount of plagiarism in the thesis. >20% (not evaluated) Is the content (names of sections and subsections 40 and enumeration of pages) in compliance with the thesis structure and -0.2 point -0.5 points aims? 41 Are the names of the thesis parts in -0.2 point -0.5 points compliance with the text? Are the titles of sections and sub-sections distinguished 6

7 42 43 logically and correctly? Are there explanations of the key terms and abbreviations (if needed)? Is the quality of the thesis typography (quality of printing, visual aids, binding) good? *In total (maximum 10 points): -0.2 point -0.5 points -0.2 point -0.5 points Reviewing date:... *Remark: the amount of collected points may exceed 10 points. Reviewer s comments: Reviewer s name and surname Reviewer s signature TABLE OF CONTENTS 7

8 SUMMARY...9 Background...9 Objectives...9 Data sources...9 Review method...9 Result...9 Conclusion...9 Keywords...9 INTRODUCTION...10 The aim...11 The tasks...11 Hypothesis...11 Indications for transplantation of teeth...11 Technique of autotransplantation...12 SELECTION CRITERIA OF THE ARTICLES. SEARCH METHODS AND STRATEGY...13 Protocol and eligibility criteria...13 Inclusion criteria...13 Exclusion criteria...13 Sources of information and search strategy :...13 Study selection and data extraction :...13 Study Variables...14 Flow Diagram...15 RESULTS...16 Selection of studies...16 Summary of articles:...17 Quantitative analysis...20 Evaluation of bias...26 DISCUSSION...27 CONCLUSION...29 PRACTICAL RECOMMENDATIONS...30 REFERENCES

9 SUMMARY Background: Autogenous tooth transplantation was first well documented in 1954 by M.L. Hale. It is a surgical movement of a tooth from its original location to another site in the mouth within the same person. The major principles of this technique are still followed today. One advantage of this procedure is that placement of an implant-supported prosthesis or other form of prosthetic tooth replacement is not needed. The purpose of this work is to highlight the viability of autogenous tooth transplantation in human patients with missing teeth, and to answer the following questions: can the autogenous transplantation of a tooth provide a high rate of success and long term functional and esthetic results? What are the criteria necessary for a successful patient selection and outcome of such a technique? Objectives: To determine the success rate of autogenous tooth transplant, long term results combined with causes of failure, as well as the required criteria of patient selection for a successful procedure. Data sources: Databases and internet (including MEDLINE/PubMed) Review method: Searches were performed during the month of December Result: Among the studies included in this research, cases presented had a high rate of success, as well as long term esthetics and functionality. Conclusion: success rates in my studies were high (mean 85%), so Autogenous Tooth Transplantation can be used as an alternative treatment to replace missing teeth. Criteria for a successful transplantation were evaluated and careful patient selection combined with good surgical skills may offer good long term results. causes of failure were analyzed, and certain factors may limit the versatility of the procedure like transplantation of teeth to the opposite jaw, and increased extra-oral time of the donor tooth. Keywords: Autogenous, Transplant, Autotransplantation. 9

10 INTRODUCTION In ancient Egypt, slaves were forced to give their teeth to their masters and those were the first reports of teeth transplantation in history [1]. The first documentation of tooth transplantation was written by Abulcassis, in Ambroise Paré, a French dentist performed the first recorded surgery with details about tooth bud transplantation in A transplantation technique for molars was reported in 1956 and until today, the general guidelines of this surgical technique are practically the same where high success rates have been achieved as well as excellent long term functional and esthetic results when combining careful patient selection with the appropriate technique [2]. However, along the years histocompatibility complex problems deemed this act rather impossible and allo transplantation (transplantation of an organ from one person to another) was abandoned and replaced with auto transplantation [1]. Auto transplantation, also known as autogenous tooth transplantation, is a well-established surgical treatment which consists of moving a tooth from one location to another in the mouth of the same individual and later restored to the size, shape, and color of the missing tooth [3]. Ideal subjects would be patients with congenitally missing teeth, patients with ectopic teeth positions, patients with severe caries, those with periodontal diseases as well as individuals who suffered teeth trauma or endodontic failure [4]. Auto transplantation uses a natural tooth rather than a prosthesis or an Osseo integrated implant to replace the missing tooth [5]. The main advantages of this procedure are the absence of alterations in the development of the maxilla and mandibular alveolar bone. This method has had high success rates. The success of autogenous transplantation of a tooth is influenced by various factors regarding the donor and recipient site, the extent of periodontal tooth damage, as the duration of the extra oral exposure of the donor s tooth during surgery and the recipient site. The skill of the surgeon plays an important role as well [4]. The aim of this work is to study the possibility of using this technique as viable treatment to replace a missing tooth. The tasks of this study are: 1) To evaluate the success rates for autogenous transplantation 2) To evaluate the necessary criteria of teeth selection for a successful outcome 3) To evaluate long term results and possible causes of failure for this procedure Hypothesis: This paper allows us to answer the following question: Can this procedure provide a natural alternative to a prosthesis or an Osseo-integrated implant to replace a missing tooth? 10

11 Indications for transplantation of teeth: There are several indications for auto transplantation of teeth, the most common one being the loss of a tooth. Ideal subjects would be patients with congenitally missing teeth, patients with ectopic teeth positions, patients with severe caries, those with periodontal diseases as well as individuals who suffered teeth trauma or endodontic failure [4]. Dental Caries and Periodontitis: The most common cause for tooth loss is dental caries. This is because the tooth is extracted. According to a database from the Oral Health Foundation 74% of all adults in the UK had a tooth extraction due to dental caries. A study conducted in Brazil in 2012 amongst 439 subjects had shown that dental caries (38.4%) and periodontal disease (32.3%) were the most prevalent conditions for tooth mortality, the latter increasing in prevalence amongst older individuals [6]. Traumatic tooth loss: Trauma to teeth is most frequent in maxillary incisors and auto transplantation is indicated in this case. According to a study conducted trauma cases comprised 2.6% amongst 800 teeth studied in 439 subjects [6]. Ectopic teeth: Another reason for transplantation is ectopic teeth. Transplantation may be considered as an alternative in cases of a severe ectopic position of maxillary canines [4]. Tumors: Transplantation is performed in case of Tumors where distal bone auto transplants, as an alternative to dental titanium implants and supra-structures, are used in jaw reconstruction cases [6]. Adontia and Hypodontia: Congenitally missing permanent teeth in one arch with signs of crowding on the opposite arch are an indication for auto transplantation. This is done after extraction of the teeth, where a maxillary premolar may be transplanted to the site of the second premolar in the mandible [3]. Teeth with Bad Prognosis: Teeth with bad prognosis, such as first molars, are more susceptible to be extracted due to caries and periodontal disease. In this case, transplantation of a third molar in the site of the first molar is frequently considered [6]. Tooth agenesis, large endodontic lesions, root resorption and fracture, juvenile periodontitis, tooth aplasia, cleidocranial dysplasia, regional odontodysplasia and other pathologies have been indications for auto transplantation [3, 6]. 11

12 Technique of Autotransplantation: The sequence of auto transplantation of teeth includes: clinical and radiographic examination, diagnosis, treatment planning, surgical procedure, endodontic treatment, orthodontic treatment, restorative treatment, and follows up. First, timing of tooth extraction is determined. Transplantation is ideally performed on the same day of extraction, otherwise within 2 6 weeks after the extraction to avoid bone resorption. Afterwards, depending on the stage of root development of the donor tooth, root-canal treatment is done either before or within 2 weeks of transplantation. Restorative treatment of transplants is also considered to avoid tooth reduction. The tooth to be extracted in the recipient site should be extracted before the donor tooth if the surgeon opts for immediate transplantation. Extraction is best done with least traumatization. And the donor tooth should be placed back in its original socket after it is removed. If any extra-oral time is anticipated, the tooth should be stored in a special solution that will maintain the viability of the periodontal ligament cells. Measurements are done in which the recipient socket is prepared a little larger than the donor using surgical round bars at low speed and cooling with saline [6]. An ideal donor tooth should be reasonably strong with good root volume and length, easy for extraction and free of periodontal disease. Surgical difficulties in tooth transplantation are another problem because every tooth has a different size and shape, unlike dental implant devices. Maintenance of healthy periodontal ligament cells on the root surface of the donor tooth as well as good tissue adaptation are taken into consideration. This in turn has a considerable impact on the healing process after auto transplantation. In turn, these cells are affected by any extension of extra oral time, leading to unfavorable results such as inflammation or root resorption. The preservation of favorable periodontal ligament (PDL) on the donor tooth is the critical factor for success. about 2 weeks after autotransplantation, reattachment occurs between the wall of recipient socket and the connective tissues of PDL of the donor root surface. healing can be achieved by cemental healing when the surface of damaged PDL is small. However, when the damaged PDL surface is large, root resorption will ensure as some of the root surface will be resorbed followed by bone apposition rather than dentine [3]. Adaptability between the recipient's bone and the root surface of the transplanted tooth plays an important role for auto transplantation. This is dependent on the blood supply and the level of nutrition reaching the periodontal ligament cells. This is a major factor contributing to success rates of auto transplantation. To optimize these rates, an optimal contact with the recipient site is needed [6]. 12

13 SELECTION CRITERIA OF THE ARTICLES. SEARCH METHODS AND STRATEGY Protocol and eligibility criteria A systematic review of the published data was conducted in accordance with the preferred reporting items for systematic reviews recommendations to determine the criteria for selection of teeth eligible for auto-transplantation, the factors that influence the success rate and causes of failure of such a technique, as well as the criteria for teeth selection associated with this procedure. Primary studies published in English, recent studies that evaluated large groups of patients that have undergone autogenous tooth were included in this study. Inclusion criteria: The inclusion criteria were applied using the components of PICOS. Primary studies (1), randomized controlled trials (2), retrospective studies in the English language (3)not older than 10 years (4) that included at least one of the study variables(5) were included in this study. Exclusion criteria: The exclusion criteria were as follows: (1) case reports, (2) reviews of articles, (3) articles older than 5 years, (4) non-primary studies, (5) non-human studies, (6) studies not including at least one of our study variables. Sources of information and search strategy: A systematic search was conducted in MEDLINE/PUBMED database. The details of the search strategy in was as follows: (Tooth autotransplantation) AND success rate OR tooth autotransplantation prognosis OR autologous tooth transplantation OR tooth autotransplantation failure NOT organ transplant NOT cancer. Study selection and data extraction: The studies identified were selected and calibrated independently to verify their eligibility.721 studies were identified through database searches. 665 studies were excluded according to exclusion criteria: 103 articles older than 5 years, 196 studies conducted on non-human species, 366 did not have full texts available, and so 56 studies were screened for title reading. Of those, 39 articles were excluded based on their title and 16 articles were eligible for abstract reading. After reading abstracts, 12 articles were eligible for full-text analysis, because 2 were case reports and 2 were systematic reviews. In between these 12 articles, 5 did not meet our inclusion criteria. Finally, after adding one article searched for manually, 8 studied were eligible for qualitative synthesis. 13

14 Study Variables The main variable in our study was the success rate of autogenous tooth transplantation. Success being defined as the presence of the tooth in the mouth without ankyloses, root resorption, normal mobility, and continuous root development. Another variable was the criteria for selection of a tooth eligible for auto transplantation: The type of donor tooth (ex: premolar, molar), the receptor site of the autotransplantation (maxilla, mandible ), the anatomy of the donor tooth root, as well as the type of surgical technique. Those variables were evaluated to determine the best outcomes of such a procedure. The age and sex of the patients were also included in our results to try underline a predisposition to success in different types of individuals. The risks for failure were investigated and cases considered as a failure included less than 4 years survival rate in the mouth, ankylosed teeth, cases with severe periodontal problems, or physiological mobility. 14

15 Flow Chart Included Eligibility Screening Identification Records identified through database searching (PubMed.com) Additional records identified through (n =721) other sources (n = 0) Records excluded: Not older than 5 years (n=105) Records screened Studies not conducted on (n = 54) humans (n=196) No Full texts (n=366) Excluded based on title (n =39) Abstracts evaluated for eligibility (n = 15) Excluded based on: Systemic/literature review (n-2) Full-text articles evaluated Case reports for eligibility (n = 2 ) (n = 11) Records excluded after reading fulltext (n=4) Records searched for manually (n=1) Records included (n=8) 15

16 RESULTS Selection of studies After screening and reviewing 54 studies, 11 were evaluated for full text reading. 4 potentially relevant studies were excluded after reading the full text because they did not include any of our study variables. Finally, after searching for one more article manually, 8 studies were included for qualitative analysis. Study characteristics Of the 8 studies, the survival and success of an autotransplantation was considered in all of them. The causes of failure were evaluated in 4 studies, and criteria for teeth selection was evaluated in 7 studies. In one study, only maxillary and mandibular molars were transplanted, in 2 others, only premolars were transplanted, in 2 other different studies, both types were present. In one study only canines were transplanted and in 3 studies molars premolars and canines were transplanted. The studies had no uniformity criteria for the evaluation of success of autotransplantation, but many coincided on some parameters. The success criteria used among the selected studies were as follows: the absence of inflammatory resorption or any inflammatory process affecting the root or the alveolar bone, the crownroot ratio, the absence of mobility, pulp vitality or the obliteration of the pulp canal, a probing depth not greater than, the absence of ankyloses. Due to the differences in definitions, the range of the success rate varied. 1 study reported a 100% success rate, while 2 studies reported a success rate greater than 90%, 3 studies reported a success rate of 70-90%, while the lowest success rate was reported by Bokelund et al. with a 40% success rate on molars. 16

17 Summary of articles: Huth et al (2013): In this study, 57 teeth were transplanted on 45 patients. of those, 37 teeth were canines, 10 were molars, 7 premolars, and 3 incisors. the aim was to determine the success rate of the procedures. The overall success was 74%, along with high patient satisfaction. the success criteria were probing depth <or = 3.5mm, mobility grade < or = 2, periotest < or = 30 as well as complete alveolar healing. the influencing parameters included oral hygiene, smoking, periodontal screening index, occlusal/proximal contacts, horizontal position, dental age, pulp obliteration and degree of displacement. the technique used in this was the one described by Anderson et al, and all auto transplantations were performed by one experienced maxillofacial surgeon. endodontic treatment was performed if periapical periodontitis or root resorption was detected. For the post-operative radiographic examination, digital radiographs were obtained to examine periapical status and bone healing and root resorption. the mean age of the patients at the time of surgery was 17. the survival rate was 96% after a mean follow up of 1.6 years. the clinical failure criteria were a periodontal probing depth > 3.5mm, a tooth mobility grade of 3, or a periotest value >30. the radiographic failure criterion was incomplete alveolar bone presenting a rarefied area larger than the periodontal ligament space surrounding the transplanted tooth. The success rate for canines was 73%, for molars 70%, for premolars 71%, and for incisors 100% Oral hygiene showed a statistically significant influence on the success rate, as did smoking, the presence of proximal contacts and pulp obliteration. [7] (table 1) Bokelund et al (2013): In this study, 162 maxillary second premolars and 49 third molars were transplanted to the mandibular 2nd premolar region of male patients. the aim was to determine whether ankyloses can be predicted based on the evaluation of the dentitions prior to surgery. after transplantation, the 211 teeth were followed up for a period of 1-29 years. the study showed that 7% of the transplanted 2nd premolars ankylosed during the first 10 years after operation, and that the rate of success for transplanted 3rd molars to the region of mandibular 2nd premolars were significantly lower. a significant association was found between ankyloses of a second premolar and infra-position of the primary 2nd molar located at the recipient site [8] 17

18 Aoyama et al (2012): This study had the purpose to evaluate the factors affecting the prognosis of auto transplanted teeth with complete root formation. the mean follow up time was 35.6 months. A total of 259 transplanted teeth were studied. among those, 27 were judged as unsuccessful cases. Among these failed cases, 23 teeth were extracted/fell out during the observation period. the causes were failure of peritransplant tissue healing (63%) and root resorption (37%) 10 variables showed a great influence on the prognosis: more than 40 years of age, donor tooth being a maxillary tooth, donor tooth being a molar, pocket depth of 4mm or more, history of dental caries and/or restoration previous root canal treatment, teeth with multiple roots, divergent root of donor tooth, 2,5 months or more of tooth absence at the recipient site, and tooth transplantation to the opposite jaw were significantly associated with unsuccessful transplantation. The other 12 variables were not significant: gender, smoking habit, state of eruption, hypertrophy or/and curvature of root, fracture of root at removal, position and site of recipient, adjacent tooth of recipient site, tooth autotransplantation to the opposite quadrant or side of the jaw. [9] Denys et al (2013): This retrospective study has for aim to provide information on long-term clinical outcome of teeth autotransplantation. the study included 137 autotransplantation cases performed on 109 subjects, with a follow, up period varying from 1week to 14,8 years. According to this study, the optimal time to transplant is when the root has reached two thirds to three quarters of the final root length. also, transplanted teeth receiving orthodontic treatment had a lower risk of ankyloses and were less likely to fail. the risk of root resorption was lower for teeth with stages one-half to three-quarters of root length at the time of autotransplantation. Molars were more susceptible to ankyloses. they concluded that this procedure can be a viable treatment alternative method in young adolescents for replacing missing because of agenesis or trauma, because 87 teeth responded positively, and only eleven out of 109 patients invited for recall loss the transplanted tooth. [10] Tanaka et al (2008): In this study only premolar donor teeth were transplanted in orthodontic patients. there was no sacrifice of premolars in the patients. the donor premolars were transplanted to the site of maxillary anterior teeth. After classifying the 28 donor premolars into three stages of root development, all transplanted teeth were checked at a chair-side observation during the latest appointment. 18

19 all donors were well-maintained in occlusion and presented a normal periodontal condition for an extensive follow-up. [11] Kvint et al (2010): This paper studied the autotransplantation of teeth in 215 patients who have undergone 269 teeth transplants by the same surgeon. 81% of the transplantations were recorded successful, 19% as unsuccessful, 25 have been extracted and 15 have survived but did not meet the criteria for success. Cases were marked as unsuccessful if the tooth was extracted or was surviving but with root resorption or ankyloses. many factors influence the results, such as the developmental stage of the tooth, donor type, duration of extra oral exposure of the tooth after surgery, damage to the root cementum and the periodontal ligament, and the experience of the oral surgeon. The success rate is reported to be over 80% when the root length of the auto transplanted premolar is 50 to 75% of the normal root length at the time of surgery. Also, according to them, a lower predictor of success was patient age greater than 20years. [12] Patel et al (2010): The aim of this study is to evaluate survival and success rates following autotransplantation of maxillary canine teeth. the survival rate was 83% with an average duration of 14,5 years in situ. The established criteria for success were: tooth presence for survival and resorption, probing depth of pockets, mobility, gingival bleeding, vitality and color. They concluded that ATT of impacted maxillary canines can be a long-term alternative and should be indicated in selective cases. Although the rate for complete success was low (no signs of resorption, mobility, and sound periodontal tissues), the survival rate can be considered favorable in some cases. [13] Plakwicz et al (2013): The sample comprised 23 developing premolars in 19 patients. their mean age at time of surgery was 12 years and 8 months, with a mean observation time of 35 months. The aim was to determine the predictability of premolar transplantation. The success rate is 91.3%, and survival rate was 100%. All transplanted premolars had normal alveolus processes at the examinations as well as normal mobility and no gingival recession, and no hard tissue pathology was presented in intraoral radiographs [14] 19

20 Quantitative analysis Primary outcome: success rate All 8 studies were included as evidence to determine the success rate of auto transplantation. The success rate of the studies was high (mean 85%). (Table of outcomes (1)) Prognostic factors of success rate: Donor tooth: when evaluating the type of donor tooth as the prognostic factor of the success of the auto transplantation, we observed that premolars presented lower failure risk than molars. Stage of root formation: the results of 4 studies were combined to evaluate the difference between the number of auto transplantation failures with respect to root formation. Receptor site: the receptor site of the donor tooth was evaluated by comparing the failure rates for auto transplantation in the maxilla and the mandible. The combination of the results in 3 studies showed a trend of fewer failures with auto transplantation in the maxilla, even though the difference was not statistically significant. Survival rate: The auto transplantation survival rate in 8 studies was 85% (mean) (table 2) Prognostic factors of survival rate: Ankyloses was an important prognostic factor of survival, because the main purpose of auto transplantation is preservation of the alveolar ridge and its continuous stimulation for development. This process is lost when ankyloses occurs. The presence of ankyloses showed a tendency toward a greater risk of loss of the auto transplanted tooth. Age of the patient: the success rate for those older than 20 years was lower than for younger patients according to Kvint et al., who evaluated the auto transplantation of one tooth in 215 consecutive patients. This is consistent with the finding that optimal time for transplantation is before final root development. Complications during surgery, such as difficult extraction, deviant root anatomy, or damaged root periodontium is a predictor for lower success rate. Prolonged extra oral exposure of the transplant tooth after extraction was associated with complications at site of surgery. Statistical analysis of the following remaining factors does not disclose predictive values: the condition of the follicle, which tooth was transplanted, and the presence or absence of bone alveolus at the recipient site. 20

21 Criteria for teeth selection: It was concluded that in adolescents, transplantation of premolars may be recommended to replace missing maxillary incisors. The best results were recorded for premolars, both maxillary and mandibular transplanted to the maxillary incisor area (success rate was 100% according kvint et al. According the study conducted by Kvint et al., transplantation of canines and molars had a lower success rate than premolars. It was suggested that poorer accessibility increased the risk of damage to canines and molars. The overall success rate for canines and molars was 81%, while premolars disclosed a higher success rate of 90%. Extracted teeth, as well as surviving teeth with bad prognosis, (ankyloses and root resorption) were registered as unsuccessful. According to Tanaka et al., who conducted a study by auto transplanting 28 premolar donor teeth in 24 orthodontic patients, 7 out of 24 premolar donors were applied to the sites of the missing mandibular second premolar. 16 donor premolars (57%) were placed at the sites of the missing maxillary central, lateral and canine. The success rate of premolar transplants in this study was 100%. (table 2) Causes of failure: In a previous study by Kim et al., evaluating the causes of failures in 182 auto transplantation cases, causal analysis of failed cases was performed. The most frequently used donor teeth were the mandibular (93 cases) and maxillary (70 cases) followed by the maxillary and mandibular premolars (12 cases) which were extracted for orthodontic treatment. During the first follow up that was achieved in 143 cases out of the total of 182, complete healing was observed in 112 cases (78.3%), incomplete healing in 22 cases (15,4%), uncertain healing in 6 cases (4.2%) and failure in 3 cases (2.1%). In those 3 failed cases, extraction was performed since early healing was not achieved and mobility higher than a normal degree persisted. Among these 3 cases, 2 cases had severe periodontal inflammation in whom no endodontic treatment was performed to the period of the first follow up. 8 months post-operative, another follow up was performed, and failure was observed in 6 cases out of 153 cases evaluated. Discomfort at the time of mastication was the chief complaint in 5 out of the 9 uncertain cases, and root resorption was observed in 4 cases. Cases with root resorption: among the patients who were followed up, root resorption was noticed in 4 cases. The mean extra oral time for these cases was 9.2mins. Cases with ankyloses: among 168 patients who were followed up without failure, ankyloses was observed in 18 cases (10.7%), which was diagnosed based on the findings of periodontal ligament loss on the radiographs. 21

22 absence of endo treatment, hemi section of donor teeth, alveolar bone loss at recipient site that results in poor crown root ratio, periodontal inflammation remaining in recipient site, short root of donor tooth, preexisting periodontal problems, or short root by apical root fracture during extraction may be the roots of causes of these failures. 22

23 Table 1. Table of outcomes (1) Author Type of study Number of cases studied Characteristic of teeth studied Study Variable presence Reich et al retrospective 44 molars Success rate, cause of failure Huth et al retrospective 57 Canines, molars, premolars, incisors Characteristics, success rate, cause of failure Aoyama et al retrospective 259 molars Success rate, cause of failure Denys et al retrospective 137 Premolars and molars Characteristics, success rate, cause of failure Tanaka et al retrospective 28 premolars X Kvint et al retrospective 269 Premolars, molars, canines Characteristics, success rate, cause of failure Patel et al retrospective 63 canines Success rate, casue of failure Plakwitz et al prospective 23 premolars Success rate, cause of failure 23

24 Table 2. Table of outcomes (2) Author Follow up period Success rate Sex of patients Age of patients (mean) Cause of failure Presence (+/-) Reich et al 19months 95,5% 14M 18F 19 Years + Huth et al 1,6 years 74-96% Not indicated 17 years mean + Aoyama et al 35,6 months (mean) 89,6% 155M 107F < > Denys et al 4,9 years mean 89 teeth 82M 55F Tanaka et al 7 years mean 100% 10M 14F Not indicated + 9to16 years old - Kvint et al 4,8 years mean 81% 114M 101F 15,2years old mean + Patel et al 14,5 years 83% Not indicated 21,8 years old mean + Plakwitz et al 35months mean 91,3% 9m 10F 13 years old mean + 24

25 Table 3. Risk of bias in individual studies Author Selection bias Performance bias Blinding of outcome assessment (detection bias) Incomplete outcome data Reporting bias Reich et al Huth et al Aoyama et al Denys et al Tanaka et al Kvint et al Patel et al Plakwitz et al Indicates low risk of bias - Indicates high risk of bias 25

26 Evaluation of bias (table 3) Selection Bias: In my studies, participants were not chosen randomly. they were all patients who had undergone at least one surgical transplantation of a tooth. as I used my table of bias at the outcome level, and since no patient can be prone to a predisposition for a better success prior of investigation I judged my articles to be of low risk of bias. Performance Bias: As it is impossible to conceal the purpose of such a procedure, I judged my articles to be of high risk of bias, Blinding of outcome assessment (detection bias): Patients studied in my articles could not possibly be blinded, as the research aims to investigate the outcomes of surgical procedures they have undergone, and the purpose of the procedure could not possibly be concealed. so, I judged my articles to be of high risk of bias at the outcome level. Incomplete outcome data: In some articles, a small number of patients did not come to follow-up for certain reasons. They were excluded from the studies and as the number of excluded patients was of low attrition and insignificant compared to the overall number of cases studied, I judged my articles to be at low risk of bias. Reporting bias: As only the authors themselves will know the accuracy of the statistics they present, I judged my articles to be of low risk of bias. 26

27 DISCUSSION the success rate of autogenous tooth transplantation was about 50% in 1950 because of root resorption and its development after transplantation. because of the lack of knowledge about the causes of root resorption and prevention. This method (autogenous transplantation) was not common. the rate of dental root resorption and the healing of periodontal diseases after transplantation have been estimated in many studies since 1990 and an increase in success rate was present. As reported by Tsukiboshi, among 250 cases, a success rate of 82% was observed in a follow up period of 6 years. a success rate of 94% in cases with incomplete roots and 84% in cases with completely formed roots was reported by Lundberg and Isaksson, while Mej`are et al. reported high success rates for matured teeth. For successful auto-transplantation, like other surgical procedures in modern medicine, cautious case selection and treatment planning are important. The proportion, as well as the competency of the donor tooth and recipient site should be precisely tested. The recipient site should have sufficient bone support and adequate attached keratinized tissue, allowing tooth stabilization and preventing inflammations and infections [15] One of the problems that the surgeon faces in tooth transplantation is the precision in preparing the bone bed of the recipient socket. Teeth transplants require recipient bone contouring and it is crucial that it has a similar size and shape to that of the donor's tooth. CARP tooth models provide a preliminary shape of the donor's tooth. Nonetheless, the long-term results of CARP tooth models depend first and foremost on the skills and experience of the surgeon. The patient's age, his profile, the morphology of tooth to be implanted, as well as the bone bed receiving the implant, along with crowding and finally the preferences of the surgeon and his patient altogether determine the treatment decisions after the extraction procedure. Patients are chosen according to the criteria listed above. After that, the surgeon and his patient discuss the possibility of an auto transplant. As for the donor tooth, it should be strong and it should have good root volume and length. It should also be rather easy to extract and free of periodontal diseases. Another issue that the surgeon faces is to do with surgical difficulties in the tooth transplantation process. This is because every tooth has its own shape and its own size. This is not the case for dental implant devices where surgeons do not face such a problem. Moreover, the surgeon must take into consideration the maintenance of healthy periodontal ligament cells on the root surface of the donor tooth, in addition to good tissue adaptation. This is because if the 27

28 periodontal ligament cells are healthy the healing process occurs without complications after auto transplantation. Additionally, the periodontal ligament cells are affected directly by any increase in extra oral time and due to that complications, such as inflammation and root resorption, may occur. It takes 2 weeks for reattachment to occur between the periodontal ligament connective tissue of the donor root surface and the wall of recipient socket after the auto transplantation. When the damaged periodontal ligament surface is small, cementum healing takes place. However, when the surface is large, some of the root surface will be resorbed and apposition of bone rather than dentine will take place [3]. A major factor contributing to the success rate of the auto transplantation procedure is the adaptability and the optimal contact between the recipient's bone and the root surface of the transplanted tooth. In addition, it greatly depends on the blood supply that reaches the periodontal ligament cells. The treatment that surgeons opt for to replace the missing tooth is the dental implant followed by tooth-supported restorations. Congenitally missing maxillary lateral incisors are substituted using dental implants instead of by auto transplantation because premolars and third molars have an unfavorable morphology to match maxillary lateral incisors. [16] Several disadvantages of dental implants are the fact that neighboring teeth undergo marginal bone loss and a resorption of the labial cortical plate around dental implants occurs. This process replaces missing maxillary incisors due to infra positioning of the implant and of the supported restorations. Long term side effects of dental implants include change in color above the gingiva at the site of the implant and periodontal injury where the periodontal tissues around the implant show progressive signs of recession. Auto transplantation has several advantages over implants where most tooth transplantation procedures can be done in a single surgery. The transplanted tooth can also serve as a bridge support or as an orthodontic anchorage. The transplanted tooth also restores its proprioceptive function and undergoes its normal periodontal healing process, allowing for a natural chewing feeling. [17] Studies comparing implants and auto transplants of developing premolars revealed that more bacteria colonize the implant site compared to the amount colonizing the transplant site or the natural tooth. Success rates are found to be 90% or higher. In fact, a prospective study containing 114 patients who underwent this procedure demonstrated that the success rate was 96%, with 84% at five years. Other studies have shown between 79 and 95% success rates, with follow-up times reaching up to 41 years [18]. 28

29 CONCLUSION success rates in my studies were high (mean 85%), so Autogenous Tooth Transplantation can be used as an alternative treatment to replace missing teeth. Criteria for a successful transplantation were evaluated and careful patient selection combined with good surgical skills may offer good long term results. causes of failure were analyzed, and certain factors may limit the versatility of the procedure like transplantation of teeth to the opposite jaw, and increased extra-oral time of the donor tooth. 29

30 PRACTICAL RECOMMENDATIONS FACTORS AFFECTING SUCCESSFUL TRANSPLANT Surgical procedures, pre-examination of the donor tooth and recipient site, fabrication of the donor tooth model using computer-aided rapid prototyping, practice on the recipient jaw Model, and surgery, as well as post-surgical care can influence the procedure s success rates. Atraumatic Procedure: This is crucial to preserve bone and periodontal support and the less the handling of the transplant the better protection of the pulpal tissue. This is to avoid growth compromise, ankyloses or root resorption and attachment loss [6]. The Development of the Root: A 96% rate of pulpal healing was observed in transplanted teeth with incomplete root formation compared to 15% for those with complete root formation. It is believed that for a successful transplantation the roots should be developed beyond their bifurcation. Radiographic evidence shows that the root has developed at least 2 to 5 mm. [18] Teeth with immature roots have less root growth after transplantation, nonetheless have higher success rates. In addition, teeth with an apical diameter greater than 1 mm have a fewer risk of necrosis due to a more probable revascularization. The American Association of Endodontists recommends that the pulp of teeth with closed apices be extirpated 7 to 14 days after transplantation; otherwise the necrotic pulp and subsequent infection may result in inflammatory resorption and the survival time of the autograft is decreased. Adequate Fixation: The splint should not force the tooth against the bone of the alveolus as not to damage the periodontium and affect the healing outcome. Flexible splinting for 7 to 10 days is recommended with sutures placed through the mucosa and over the occlusal surface of the crown because this permits some functional movement of the transplant and stimulates periodontal ligament cellular activity and bone repair. and attention to oral hygiene is necessary to avoid periodontal inflammation around the transplanted tooth. Placing the tooth at the same occlusal level as the donor site is crucial for it to develop a long root. However, if the donor tooth has a mature root, it is placed below the occlusal level to prevent postoperative trauma. 30

31 Periodontal Healing: It occurs after 7-8 weeks. It radiographically appears as a continuous space around the root with absence of root resorption and the presence of a lamina dura. The donor tooth should be placed so that 1 to 2 mm of the width of the periodontal ligament stays above the bone crest because position has a large impact on healing. Unfortunately, vertical bone resorption can occur if placement is too deep or even too shallow. Infection at the host site and postoperative control of supra gingival plaque: Infection decreases the success rates and this is because of bacterial contamination of either the pulp tissue or the dentinal tubules leading to inflammatory resorption. For this reason, patients are recommended to use chlorhexidine gluconate (0.12% in aqueous solution) for several days preoperatively. Patients with certain systemic diseases are contraindicative to surgery. Those include cardiac anomalies, poor oral hygiene and inadequate width of the alveolar bone because an insufficient bucco palatal or bucco-lingual width of the recipient may be a risk factor for resorption of the alveolar ridge [18]. proper adaptation between the root surface of the transplanted tooth and the bony walls of the recipient site is Another important factor for a successful auto transplantation. for successful procedure, careful planning is essential. A careful examination to the donor tooth and recipient site should be done to ensure adequate fit and that a root canal treatment is possible. the healing pattern of the auto transplanted tooth is defined by Preservation of healthy periodontal ligament cells. the viability of periodontal ligament cells is affected by the increased extra-alveolar time of the donor tooth and may lead to unfavorable results, such as root resorption proper adaptation between the root surface of the transplanted tooth and the bony walls of the recipient site is another important factor for a successful auto transplantation. It is recommended by The American Association of Endodontists that to avoid the infected necrotic pulp inducing inflammatory resorption and early loss, teeth with closed apexes have their pulps extirpated between 7 and 14 days. the fact that only 15% of teeth with complete root development are revitalized after transplantation justifies this, in contrast with 96% of teeth with incomplete root formation. [19] 31

32 the donor tooth, recipient site, the duration and method of splinting after surgery, and the timing of endodontic treatment of the transplanted tooth are the factors affecting the prognosis of auto transplantation the healing of periodontal ligament (PDL) cells, which depends on the vitality of PDL cells attached to the root surface of the donor tooth, is the decisive factor of the prognosis. Therefore, extraction not damaging the root surface of the donor tooth during extraction as well as a fast transplantation in the recipient site are the key points for the successful procedure. Also, the root maturity of donor tooth plays an important role regarding the prognosis of auto transplantation. Any tooth can be the donor for the auto transplantation, whether its root is opened or closed, but the teeth with half to three-quarter root development are the best. sufficient alveolar bone support in all dimensions should be expected from ideal recipient sites, as well as an appropriate amount of attached keratinized tissue, and no inflammation. However, auto transplantation can also be used in cases of localized severe periodontitis which does not show promising prognosis. Nethander et al. reported that it was possible for an auto transplanted tooth to obtain better blood supply by using a 2-stage operation technique. Lee et al. also investigated the fact that waiting for 2-4 weeks before transplanting the tooth showed good healing in severe periodontal cases. The auto transplanted tooth should be held in the recipient site for periodontal healing. functional movement of teeth can be allowed through flexible splinting, which stimulates the activity of PDL cells. Tsukiboshi reported that splinting is not essential but beneficial in most of the auto transplantation cases, and the tooth should be splinted between 2 weeks and 2 months depending on whether the status of mobility improvement. [20] REFERENCES 32