Impacted Maxillary Canine with Curved Apex: Three-Dimensional Guided Protocol for Autotransplantation

IntroductionMaxillary canines play a crucial role in dental and facial aspect, arch expansion, and efficient occlusion. When surgical exposure measures cannot be executed or the patient does not agree to take the treatment, autotransplantation should be considered. The aim of this case report was to describe a novel surgical technique using virtually planned three-dimensional (3D)-printed templates for guided apicoectomy and guided drilling of the recipient site for autotransplantation of an impacted maxillary canine with a curved apex.MethodsA 42-year-old man complaining of pain and increased mobility in the maxillary left primary canine came to the clinic. Autotransplantation of the impacted canine was completed using altered methods from guided implant surgery to manufacture 3D-printed templates. After a full-thickness mucoperiosteal flap elevation, the surgical template for the guided osteotomy and apicoectomy was inserted. This 3D-printed guide allowed the clinician to perform a quick and precise removal of the curved apex, providing an atraumatic extraction of the impacted canine throughout the cyst. Three further 3D surgical guides for implant burs and a 3D replica tooth were printed to modify the recipient socket. After the final position, the tooth was semi-rigid splinted to the adjacent teeth.ResultsFollow-up at 2 years showed complete regeneration of the palatal defect and remodeling of the bone surrounding the maxillary canine.ConclusionsDigitally planned procedures can facilitate the complex execution of an autotransplantation, reducing the treatment chair time and the morbidity for the patient as well as increasing the predictability of the result.     

Guided Osteotomy and Guided Autotransplantation for Treatment of Severely Impacted Teeth: A Proof-of-Concept Report

IntroductionThe aim was to present a novel surgical technique using virtually preplanned 3-dimensional (3D)-printed templates for guided osteotomies. These were to ensure atraumatic uncovering of a severely impacted donor tooth including guided drilling of the recipient alveolus followed by a secure autotransplantation procedure.MethodsThis report presents an autotransplantation procedure of a 14-year-old patient with a severely impacted second premolar and extensive contact to the roots of the adjacent teeth and the inferior alveolar nerve. Autotransplantation of the impacted premolar was virtually performed using modified methods from guided implant surgery in order to prefabricate 3D-printed templates with the aid of a fully digital workflow.ResultsSatisfactory treatment could be achieved using surgical templates for guided osteotomies of the surgical access, guided drilling of the recipient site, and occlusal reference template ensuring autotransplantation in the appropriate 3D location of the graft. An atraumatic approach could be ensured with an extraoral time of 46 seconds by 1 fitting attempt; no injuries or altered sensation of the inferior alveolar nerve were present. A vital natural tooth could be observed.ConclusionsThis innovative technique uses for the first time a fully implemented digital workflow for guided osteotomies, guided drilling, and guided autotransplantation of a severely impacted tooth. 3D-printed templates could ensure a guided atraumatic approach and facilitate highly complex treatments by virtually implementing recommended guidelines in future autotransplantations.     

Fully Guided Tooth Autotransplantation Using a Multidrilling Axis Surgical Stent: Proof of Concept

IntroductionDigital technology has been progressively introduced into tooth autotransplantation to enhance both treatment planning and surgery. The aim of this report was to describe a novel protocol for fully guided tooth autotransplantation.MethodsThis report includes 10 consecutive patients treated with a complete virtual planning and a multidrilling axis surgical guide in combination with the computer-aided rapid prototyping model.ResultsAll transplanted teeth fulfilled the criteria for success over a mean follow-up duration of 13.1 months. No signs of progressive root resorption or pain were found during follow-up. One case required minimal adjustment of the surgical stent to allow correct seating, whereas a second case could not be performed fully guided because of limited mouth opening.ConclusionsOur protocol for fully guided tooth autotransplantation is a viable option that involves minimal bone preparation in a short surgical time. Future research should focus on further investigation of the benefits of this novel protocol in a larger sample.     

Real-Time Guided Endodontics with a Miniaturized Dynamic Navigation System Versus Conventional Freehand Endodontic Access Cavity Preparation: Substance Loss and Procedure Time

IntroductionThis study aimed to evaluate substance loss and the time required for access cavity preparation (ACP) using the conventional freehand method (CONV) versus a miniaturized dynamic navigation system of real-time guided endodontics (RTGE) in an in vitro model using 3-dimensional–printed teeth.MethodsNine human anterior maxillary teeth were selected and micro–computed tomographic scanned. Root canals were virtually reduced to 2 mm below the cementoenamel junction. The teeth were digitally duplicated and mirrored to yield 6 different models with 6 single-rooted teeth each. The models were 3-dimensionally printed using radiopaque resin and consecutively mounted on a dental mannequin for ACP. Two operators with 12 and 2 years of clinical experience, respectively, received 6 models (36 teeth) each and performed ACP on half of the models using RTGE (after digital planning) and CONV on the other half 2 weeks later. The time was recorded. Postoperative substance loss was measured by cone-beam computed tomographic imaging. The differences in time and substance loss between the methods and operators were evaluated by the t test.ResultsOverall, substance loss was significantly lower with RTGE than CONV (mean = 10.5 mm³ vs 29.7 mm³), but both procedures took a similar time per tooth (mean = 195 vs 193 seconds). Operator 1 (more experienced) achieved significantly less substance loss than operator 2 with CONV (mean = 19.9 vs 39.4 mm³) but not with RTGE (mean = 10.3 vs 10.6 mm³).ConclusionsRTGE is a practicable, substance-sparing method performed in comparable time as CONV. Moreover, RTGE seems to be independent of operator experience.     

Tooth autotransplantation using an interdisciplinary approach to rehabilitation in a young patient: Case report with 7-year follow-up

This case report demonstrates the possibility of functional and aesthetic rehabilitation using an interdisciplinary approach in a child following avulsion of a tooth. Autotransplantation after the development of calcific metamorphosis of the pulp and acute apical periodontitis provided satisfactory repair after root canal treatment. A 7-year-old white boy avulsed the right maxillary central incisor (tooth 11). The extra-alveolar time exceeded 60 minutes, and this triggered external replacement resorption of the avulsed tooth. At 11 years of age, the child underwent tooth autotransplantation. After 4 years of follow-up, intraoral clinical and radiographic examination led to the diagnosis of calcific metamorphosis of the pulp and acute apical periodontitis. The patient had minimally invasive root canal treatment, orthodontic treatment and esthetic rehabilitation with a porcelain crown. Control periapical radiography and tomography of the autotransplanted tooth after 7 years revealed bone repair in the periapical region. This case report indicates that tooth autotransplantation can be used to replace anterior teeth after avulsion followed by replacement resorption. Interdisciplinary management helped to maintain the esthetics and function of the rehabilitated area.     

A case of tooth autotransplantation after long-term cryopreservation using a programmed freezer with a magnetic field

This case report describes the treatment of a skeletal Class III malocclusion with autotransplantation of a cryopreserved tooth. To gain an esthetic facial profile and good occlusion, extraction of bimaxillary premolars and surgical therapy were chosen. The patient had chronic apical periodontitis on the lower left first molar. Although she did not feel any pain in that region, the tooth was considered to have a poor prognosis. Therefore, we cryopreserved the extracted premolars to prepare for autotransplantation in the lower first molar area because the tooth would probably need to be removed in the future. The teeth were frozen by a programmed freezer with a magnetic field (CAS freezer) that was developed for tissue cryopreservation and were cryopreserved in −150°C deep freezer. After 1.5 years of presurgical orthodontic treatment, bilateral sagittal split ramus osteotomy was performed for mandible setback. Improvement of the facial profile and the occlusion were achieved in the retention phase. Six years after the initial visit, the patient had pain on the lower left first molar, and discharge of pus was observed, so we extracted the lower left first molar and autotransplanted the cryopreserved premolar. Three years later, healthy periodontium was observed at the autotransplanted tooth. This case report suggests that long-term cryopreservation of teeth by a CAS freezer is useful for later autotransplantation, and this can be a viable technique to replace missing teeth.     

Sinus floor elevation via the maxillary premolar extraction socket with immediate implant placement: a case series

Background: When immediate implant placement is considered for teeth with close proximity to the sinus floor, apical extension of the osteotomy is significantly limited, and often a staged approach is used. Implant placement into fresh extraction sockets and sinus floor manipulation using bone‐added osteotome sinus floor elevation with implant placement are techniques most often used independently or sequentially. Very few reports have described the combined use of immediate implant placement in fresh sockets and the bone‐added osteotome sinus floor elevation technique. Methods: We present five cases in which a maxillary premolar was extracted and an implant placed into the extraction site with simultaneous abfracture of the sinus floor using osteotomes. All teeth were extracted atraumatically, and sockets carefully debrided and checked for integrity of the walls. After ideal osteotomy preparation, particulate bone graft was placed in the osteotomy and appropriately sized osteotomes were used for sinus floor elevation. After sufficient elevation, implant placement was completed and particulate bone was packed in the bone–implant gap when indicated. Results: All implants were restored after a minimum healing period of 6 months. At the time of final restoration, bone was seen surrounding the implants from the apical portion to the most coronal thread. All five implants healed without complications and were in function for periods ranging from 6 to 12 months. Conclusions: Immediate implant placement with simultaneous osteotome sinus floor elevation is an advantageous combination of two successfully used techniques. This combined approach can significantly reduce the treatment time for implant therapy in teeth with close sinus proximity and provide the operator with the ability to place implants of desired length.     

Success,Survival Rate,and Soft Tissue Esthetic of Tooth Autotransplantation

IntroductionThe aim of this retrospective study was to assess the success, survival rate, and soft tissue esthetic of autotransplanted teeth.MethodsThis study included patients with at least 1 tooth autotransplanted to the maxilla during childhood or adolescence. The autotransplantation technique included the removal of an immature tooth from a donor site and its placement in the maxilla as a replacement for a missing or extremely compromised tooth. The cases were properly restored to ensure function and esthetic. To be considered successful, the tooth should be asymptomatic at the time of assessment, no pain to palpation and percussion, have no signs of apical periodontitis or a sinus tract, have a periodontal probe ≤3, and have an absence of root resorption and development of at least 70% of the normal root. The esthetic evaluation of the soft tissue was based on the pink esthetic score and graded as very unsatisfactory, unsatisfactory, poor, fair, good, or excellent. Data were statistically analyzed at a significance level of 5%.ResultsThirty-five patients (23 males and 12 females) had 43 anterior teeth replaced, including 42 central incisors and 1 lateral incisor. The follow-up period ranged from 1–25 years. In regard to success and the survival rate, 43 teeth were assessed; 34 cases (79.07%) were considered successful and 9 (20.93%) unsuccessful. Only 1 tooth was lost, and 42 teeth remained functional (survival rate = 97.67%). In regard to the esthetic, 40 teeth could be assessed and were considered as excellent (30%), good (35%), fair (27.5%), and poor (7.5%); there were no reports of unsatisfactory or very unsatisfactory cases.ConclusionsTooth autotransplantation can be considered a valid procedure to replace lost teeth in the maxilla, presenting high survival and success rates. The overall esthetic of the patients was considered as satisfactory.     

Guided Access Cavity Preparation Using Cost-Effective 3D Printers

IntroductionThe purpose of this in vitro study was to evaluate the accuracy and precision of desktop 3D printers when fabricating stents for guided endodontics.MethodsA stent was designed using planning software for guided endodontic access on a typodont model. Four different 3D printers were used to fabricate an identical stent, one per printer. Each stent was then used to gain access to the artificial endodontic canal on a typodont tooth and was repeated 10 times per stent by the same operator. Each of the accessed typodont teeth were scanned by a reference scanner and then imported into the inspection software. Inspection software used a best-fit alignment to automatically calculate absolute deviation at the base and tip of the bur.ResultsThe mean distances between the planned and actual positions of the bur were low, ranging from 0.31 to 0.68 mm. Statistically significant differences were found among the 4 groups (F_3,36 = 10.67, P < .05). Post hoc comparison revealed that Group Form2 significantly varied from Groups Form3 and Carbon (P < .05 and P < .05, respectively). Group Form3 obtained the most accurate and most precise axial deviations both coronally and apically.ConclusionsAll of the printers tested produced stents for guided access that allowed for a high level of accuracy in obtaining access to the artificial endodontic canal, which would justify the trial of cost-effective 3D printers for guided endodontic access and necessitates further clinical research on teeth with pulp canal obliteration.     

Twelve-year follow-up of an autogenous mandibular canine transplant

Transplantation is the transfer of tissue or an organ from 1 site to another in the same person or between different persons. A transplantation in which donor and recipient are the same individual has been termed autogenous transplantation, autoplastic transplantation, or autotransplantation. The purpose of this report was to describe a patient undergoing autotransplantation of an impacted mandibular canine to its normal position in the mandible and the 12-year follow-up. Five years after the surgical procedure, the patient presented with pulp canal obliteration in the autotransplanted tooth. Twelve years after the autotransplantation, the tooth position was stable despite pulp canal obliteration, but with no sign of inflammatory resorption or a periapical lesion. In addition, there was no sign of replacement resorption (ankylosis). The endodontic literature has shown that the prognosis of patients undergoing autotransplantation may be good under specific considerations. Therefore, the technique may be a treatment plan option for the replacement of missing teeth.     

Long-term outcomes 1–20 years after autotransplantation of teeth: clinical and radiographic evaluation of 66 premolars and 8 molars

In this retrospective study we investigated the long-term survival of autotransplanted premolars and molars with incompletely developed roots. The presence of the transplanted teeth and their outcome after autotransplantation was ascertained from clinical and radiographic evaluation by a maxillofacial surgeon or dentist. Kaplan Meier survival curves were estimated for the total population and for the two groups (premolars and molars).Fifty-one patients with 74 transplanted teeth were included, and the median duration of follow-up was 10 (range 1–20) years. Four of 66 premolars and one of 8 molars were removed and the cumulative survival was 95.4% (95% CI 90.3 to 100). The difference in survival between the premolars and molars was not significant. These results show that the long-term survival of autotransplanted teeth is good. Replacement of a single tooth by autotransplantation should therefore always be considered and is preferred when a suitable donor tooth is available.     

Variability and patterning in permanent tooth size of four human ethnic groups

AimsDental dimensions vary between different ethnic groups, providing insights into the factors controlling human dental development. This paper compares permanent mesiodistal crown diameters between four ethnic groups highlighting patterns of tooth size between these groups and considers the findings in relation to genetic and environmental influences.Methods and resultsMesiodistal crown dimensions were recorded using standardised manual measurements on dental casts derived from four different human populations: Southern Chinese, North Americans of European ancestry, Modern British of European ancestry and Romano-British. Analyses based on double determinations showed that measurements in all study samples were reliable to an accuracy of 0.1 mm. The Southern Chinese sample was found to have the largest teeth overall, whereas the Romano-British sample generally displayed the smallest mesiodistal crown dimensions (p < 0.001). However, the Modern British sample had the largest maxillary central incisors, mandibular central and lateral incisors, and mandibular canines, while the North American sample had the largest maxillary first and second molars. Comparisons of coefficients of variation for teeth within each class showed that the later-forming teeth displayed greater variation in mesiodistal size than the earlier-forming teeth.ConclusionThe different patterns of tooth size observed between the study samples are thought to reflect differences in the relative contributions of genetic, and environmental influences to dental development between the four populations. For example, it is proposed that major environmental insults during the early life of Romano-Britons, including recurrent illnesses, poor nutrition and excessive lead ingestion, contributed to the reduction in size and greater variability of their later-forming teeth. Using a standardised methodology, significant differences in mesiodistal crown diameters have been demonstrated between four human ethnic groups. There were also distinct differences in the patterns of crown size between the groups, with the later-forming teeth in each type generally showing greater size variation.     

下颌支内阻生第二磨牙自体移植1例报告

本文报告1例下颌支内阻生第二磨牙自体移植病例。利用数字化外科、微创拔牙等技术将下颌支内阻生第二磨牙取出后即刻自体移植至原第二磨牙区,同期将自体骨粉填入移植牙颊侧和远中骨缺损区,弹性固定移植牙。术后咬合关系良好,即刻动度I度,骨缺损得到填充修复。术后6个月行根管治疗,1年后经临床和影像学检查移植牙愈合良好。下颌支内阻生磨牙自体移植至缺失磨牙区可以成为自体牙移植术的适应证。     

Autotransplantation of a tooth using guided tissue regeneration

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

Simulation of postoperative occlusion and direction in autotransplantation of teeth: application of computer-aided design and digital surgical templates

Autotransplantation of teeth requires optimisation of both occlusion and direction to ensure minimal injury to the dental crown and the alveolar bone. We describe a method that could simulate postoperative occlusion and direction of the donor tooth by using CAD and digital surgical templates, and evaluate the postoperative effect in five patients who had teeth autotransplanted. Computed tomographic data were imported into ProPlan CMF 3.0 software, the donor tooth was simulated to replace the recipient site according to the position of the occlusion and alveolar bone, and a digital template was designed to guide preparation of the socket. A computer-aided, rapid prototyped, tooth was used to match the socket and, finally, an occlusal template was designed to ensure that the donor tooth was in the simulated position. We compared the position of the tooth in the simulation with its postoperative position using ProPlan CMF 3.0 software. In this way it was possible to simulate and guide the donor tooth accurately to the recipient site. At six-month follow up all teeth had survived successfully. Given the efficiency and precision of placement and the success, we conclude that CAD can successfully help to simulate occlusion and direction in autotransplantation of teeth while simplifying the procedure.     

Anatomically guided implant site preparation technique at molar sites

Immediate postextraction implant placement in the areas of multiradicular teeth is a difficult procedure in view of having to place the implant in an ideal position without jeopardizing its initial stability. The surgeon often faces the problem of directing the initial osteotomy in the medial portion of the alveolus with the difficulty of engaging the inter-radicular septum of the extraction socket. The drill may slip continually leading to an inaccurate site preparation, and consequently to a deficient implant insertion. The fixture is often placed directly into either one of the extraction sockets of the tooth to be replaced. The anatomically guided site preparation technique is a very useful tool to perform implant placement in the areas of multiradicular teeth. This approach of implant insertion consists of a progressive preparation of the implant site using the anatomy and geometry of the root of the multiradicular teeth to be extracted as a reference and as an aid to engage the inter-radicular septum. This places the implants in a favorable and proper position from a biomechanical and occlusal standpoint. The objective of this article is to describe the anatomically guided implant site preparation technique as an aid to favorably place dental implants in multiradicular teeth postextraction.     

A Cadaver-based Comparison of Sleeve-guided Implant-drill and Dynamic Navigation Osteotomy and Root-end Resections

IntroductionThis study compared the accuracy and efficiency of fully guided static and dynamic computer-assisted surgical navigation techniques for osteotomy and root-end resection (RER).MethodsFifty roots from cadaver heads were divided into two groups: fully guided static computer-assisted endodontic microsurgery (FG sCAEMS) and dynamic computer-assisted endodontic microsurgery (dCAEMS) (all, n = 25). Cone-beam computed tomography scans were taken pre and postoperatively. The osteotomy and RER were planned virtually in the preoperative cone-beam computed tomography scan and guided using 3D-printed surgical guides in the FG sCAEMS and 3D-dynamic navigation system in the dCAEMS. The 2D and 3D deviations and angular deflection were calculated. The osteotomy volume, resected root length, and resection angle were measured. The osteotomy and RER time and the number of procedural mishaps were recorded.ResultsFG sCAEMS was as accurate as dCAEMS, with no difference in the 2D and 3D deviation values or angular deflection (P > .05). The osteotomy and RER time were shortened using FG sCAEMS (P < .05). The FG sCAEMS showed a greater number of incomplete RERs than dCAEMS. Osteotomy volume, RER angle, and root length resected were similar in both groups (P > .05). FG sCAEMS and dCAEMS were feasible for osteotomy and RER.ConclusionsWithin the limitations of this cadaver-based study, FG sCAEMS was as accurate as dCAEMS. Both FG sCAEMS and dCAEMS were time-efficient for osteotomy and RER.