A Novel Simplified Workflow for Guided Endodontic Surgery in Mandibular Molars With a Thick Buccal Bone Plate: A Case Report

One of the challenges in apical surgery in mandibular molars is the thick buccal cortical bone plate, which might lead to access errors, damage to neighboring teeth, and injury to healthy tissue. Surgical guide templates with 3-dimensional (3D) impressions have been suggested for use in such cases, allowing greater precision. Usually, this technique involves a cone-beam computed tomography (CBCT) examination related to a 3D oral scanning to generate surgical templates printed from 3D imaging data. This study reports a novel workflow possibility in which apical surgery is performed with the aid of a surgical guide planned only with CBCT, excluding the need for 3D oral scanning. A 32-year-old woman presented with asymptomatic apical periodontitis and external root resorption on the mesial root of tooth #19. A surgical template was planned using only the patient's CBCT scan to provide precise access to the lesion and remove a mandibular cortical bone block. The procedure was carried out with apicoectomy, root-end preparation, and retrograde filling, and the bone block was repositioned before suture. No postoperative complications were reported. After 1 year, the patient presented asymptomatic, and a CBCT scan confirmed bone healing. The current 3D-printed guides may be planned and printed through a novel simplified workflow with a CBCT scan only, which allows its application in apical surgery for precise apex and surgical site location.     

Fabrication of custom oral positioning devices in head and neck proton radiotherapy

With complex head and neck diseases that closely approximate crucial organs or have advanced spread and cannot be surgically resected, intensity modulated proton beam radiotherapy is favored due to its superior dose targeting through magnetic manipulation of the proton energy. A radiation mask and an oral positioning device immobilize craniofacial, cervical, and oral structures for accurate and reliable radiation delivery. Widely available prefabricated thermoplastic oral positioning devices are manufactured in standardized forms and materials that unpredictably affect the proton beams’ pathways and range. This technique article showcases a workflow that combines analog and digital dental techniques to produce a customized 3D-printed oral positioning device within 2 appointments.     

Rehabilitation of long-term mandibular defects by whole-process digital fibula flap combining with implants: A case report

Currently, the gold standard and workhorse in mandibular reconstruction is the free vascularized fibula flap. Particularly for patients who have had mandibulectomy for a long time, it is still difficult to precisely reconstruct the mandibular contour and successfully restore the patient's chewing function and esthetics. For the restoration and rehabilitation of long-term mandibular abnormalities, three-dimensional (3D) virtual surgical planning (VSP) and 3D-printed surgical guides are essential. Digital design and manufacturing were used to improve the accuracy of prostheses and facilitate occlusal reconstruction. Therefore, equipped with the methods of 3D VSP, 3D-printed surgical guides, free vascularized fibular flap, and immediate dental implants, this clinical report provides a feasible solution for mandibular reconstruction.     

Three-dimensionally printed personalized guide plate for percutaneous radiofrequency thermal coagulation in idiopathic trigeminal neuralgia

Radiofrequency thermocoagulation (RFT) is used widely for the treatment of idiopathic trigeminal neuralgia (TN). Precise puncture and placement of the electrode needle tip are crucial for successful RFT. This technical note introduces a novel method for performing RFT using a customized, three-dimensionally (3D)-printed guide plate. Eleven patients with idiopathic TN were treated using this method between February and July 2016. Three had V2 branch TN and eight had V3 branch TN. Punctures in eight patients were successful at the first attempt; slight adjustments were required subsequently in the other three patients. The puncture time in all cases was less than 1 min. The patients reported pain relief immediately after RFT, and no complications were observed in any patient. Thus, the customized 3D-printed guide plate offers the advantages of precise placement of the puncture needle and minimal complications.     

口腔下颌运动教学辅助系统的开发

目的：开发下颌运动教学辅助系统，利于口腔生理教学。方法：利用计算机图形学技术，建立一个下颌骨三维数据模型，从三维六自由度下颌运动轨迹描记仪MT－1602（德国Hansen公司）获得了下颌运动轨迹原始数据，根据刚体运动规律，Microsoft Visual C 软件编程。结果：该系统能根据实测的运动轨迹真实显示下颌运动，轨迹和模型运动随意切换显示，并且此三维下颌模型能被任意旋转，从任何需要的角度来观察下颌运动。结论：该系统对下颌运动教学有较大意义。     

Comparison of two computer-assisted surgery techniques to guide a mandibular distraction osteogenesis procedure. Technical note

The accuracy of distracted facial bone displacement depends on the preoperative clinical assessment, surgical planning and technique. The aim of this study was to evaluate two different techniques to guide the mandibular distraction surgical procedure using an intraoral device. This study was performed on a fresh cadavre. 3D reconstructions from a computed tomographic (CT) acquisition were used for the two techniques. The first technique comprised a customised stereolithographic template and the second technique used a computer-assisted surgery (CAS) unit to guide the osteotomy and the positioning and screwing of the distractor device. Both methods were planned and compared with the same 3D software. The authors discuss the feasibility and reliability of the two techniques. The accuracy of the two techniques appears to be comparable for clinical applications, although the rapid prototyping template technique appears to be more satisfactory.     

一种离体牙三维重建装置的构建

目的:构建一种基于口腔数字化X线设备的离体牙三维重建装置(three-dimensional Reconstruction Device,3DRD).方法:以牙科专用X线片机(Gendex 765DC)作为射线源,数字化X线成像系统(RVG)作为二维探测器,设计研制载物台,构成3DRD,对收集的离体牙进行投影,然后采集数据并进行迭代重建,生成断面图像和三维图像.然后以μCT扫描后生成的图像作为参照,使用计算机辅助检测软件对3DRD生成的可视化图像进行分析和评价.结果:3DRD能够构建离体牙的三维图像,但与μCT比较在某些细微结构如细小的根管侧支所构建图像的分辨率略差.结论:3DRD为牙体形态的研究提供一种经济而无损的三维成像途径,拓展了原有数字化X线设备的应用范围.     

A novel ‘surgeon-dominated’ approach to the design of 3D-printed patient-specific surgical plates in mandibular reconstruction: a proof-of-concept study

Three-dimensionally (3D) printed patient-specific surgical plates have been proposed to facilitate mandibular reconstruction and are attracting extensive attention. We have recently reported the high accuracy of 3D-printed patient-specific surgical plates used in head and neck reconstruction. Based on this previous work, the current study proposes a novel ‘surgeon-dominated’ approach to the design of 3D-printed patient-specific surgical plates. The aim of this proof-of-concept study was to explore the workflow and technical procedures of the surgeon-dominated approach. The workflow includes virtual surgery, the design and printing of patient-specific surgical devices, and real surgery. The prototype of the patient-specific surgical plate was designed by surgeons and further optimized for 3D printing by engineers. Different types of mandibular defect were tested to confirm the wide applicability of this approach. Cases in which this approach was used were reviewed and the duration of time spent on each case studied. Based on a total of 16 patients, the time spent on virtual surgery and plate design was 18.83 ± 13.19 hours, and the time taken for 3D printing, post-processing, and product delivery was 162.9 ± 55.15 hours. Therefore, this novel surgeon-dominated approach is feasible and time-saving, which would likely promote the wide application of patient-specific surgical plates and lead to a new era of ‘digitization and precision’ in mandibular reconstruction.ClinicalTrials.gov registration: NCT03057223.     

The treatment of patients with mandibular fractures in the angle area using an intraoral monomaxillary device]

Indication for and the technique of applying an oral monomaxillary device to the treatment of mandibular fractures in the corner are described. This device was effectively used in the treatment of 27 patients. The technique of the device application is simple and non-traumatic, it permits an early start of functional physiologic treatment. The authors recommend the device as a simple means of treatment of mandibular fractures in the corner.     

Comprehensive virtual orthognathic planning concept in surgery-first patients

The surgery-first concept is becoming increasingly popular in orthognathic surgery since it offers major advantages such as a reduction of treatment duration and an increase in patient satisfaction by eliminating phases of presurgical orthodontic decompensation. Here, we present a novel interdisciplinary pathway of a fully virtual orthodontic-surgical planning concept in a surgery-first setting using a 3D-printed cutting guide and a customised maxillary implant for the Le Fort I osteotomy as well as a CAD/CAM-based stereolithographic final splint. Patient data from cone-beam computed tomography of the skull and a full arch dental scan were processed using the OnyxCeph^3TM software (Image Instruments). A mutual computer-aided surgical simulation was conducted by the orthodontist and the oral and maxillofacial surgeon to determine the three-dimensional maxillary and mandibular movements. In a separate virtual planning session, the surgeon designed a customised maxillary guide and implant for precise intraoperative transfer (Geomagic Freeform Plus software, 3DSystems). A 3D-printed CAD/CAM-based final splint was fabricated by the orthodontist and used for accurate mandibular repositioning. We established a comprehensive virtual interdisciplinary orthognathic workflow and successfully applied this concept with a high level of accuracy in a series of surgery-first patients with different types of dentofacial anomalies. This novel fully computer-based pathway offers a high potential to improve the outcomes of orthognathic surgery and reduce total treatment time in the management of the orthognathic patient.     

Fully digital fabrication of an occlusal device using an intraoral scanner and 3D printing: A dental technique

This dental technique describes a fully digital method for fabricating occlusal devices using a complete-arch intraoral scan and 3D printing. The maxillary and mandibular arches of a healthy, fully dentate volunteer were digitized using an intraoral scanner. A second scan and modified recording of the centric relation enabled a virtual arrangement of the maxillary and mandibular arches, both in centric relation and in the desired vertical dimension of occlusion. An occlusal device was subsequently designed virtually and fabricated from a light-polymerizing acrylic resin using a 3D printer. The occlusal device was tested for fit, occlusion, and patient-friendly handling. As only minor occlusal corrections were required, the fully digital procedure described is suitable for the fabrication of occlusal devices.     

Development of a novel resection and cutting guide for mandibular reconstruction using free fibula flap

Introduction

The authors developed a semi-standardised resection and cutting guide for mandibular reconstruction with free fibula flap based on data of mandible sizes and angles.

Spatial deviations of the temporomandibular joint after oncological mandibular reconstruction

Spatial deviations of the temporomandibular joint (TMJ) after oncological mandibular reconstruction are important to the aesthetic and functional rehabilitation. The aim of this study was to clarify whether and how three dimensionally (3D) printed patient-specific surgical plates, and the preservation of the condyle or ramus, affect spatial deviations of the TMJ. A total of 33 patients who underwent mandibular reconstruction via computer-assisted surgery were included. Regarding absolute deviations, patients in the 3D-printed plate group showed smaller TMJ deviations compared to those in the conventional plate group. There was no difference in absolute deviations of the TMJ regardless of whether the condyle or ramus was preserved. Regarding physiological deviations, the impact on the contralateral TMJ was smaller in the 3D-printed plate group. Patients with both the condyle and ramus removed had significantly higher deviations of the condyle and joint space. In summary, 3D-printed patient-specific surgical plates improved the spatial accuracy of the TMJ. Under physiological conditions, TMJ deviations on the operated side were mainly affected by the preservation of the condyle. Removal of both the condyle and ramus caused more severe spatial interference to the TMJ; this should be further confirmed.     

Three-dimensional CAD/CAM reconstruction of the iliac bone following DCIA composite flap harvest

This article reports a new technique to restore iliac bone integrity with a customized titanium device designed by CAD/CAM, in patients undergoing deep circumflex iliac artery (DCIA) composite flap harvest. Eight consecutive patients who underwent the repair of major head and neck defects with DCIA flaps were enrolled retrospectively. Computed tomography scans of the pelvis were obtained preoperatively. Starting from DICOM data, each personalized device was designed using modelling software and was finally made by additive manufacturing using a laser sintering machine. After surgery, the patients were followed up at 3-month intervals to evaluate the incidence of complications and the long-term outcome at the donor site. A subcutaneous seroma developed in one patient and an inguinal skin burn occurred in another. At a median follow-up of 12 months, the patients did not report pain, or any gait or sensory disturbance at the donor site. There was no occurrence of bulging, herniation, or instability or inflammation near the device for the entire follow-up duration. All patients were satisfied with the aesthetic result. In conclusion, reconstruction of the iliac bone with a customized device is safe and well tolerated. We recommend use of this device in patients deemed at high risk of herniation. Further studies are needed to confirm the stability of the device in the long term.     

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.     

Computer-aided Design/Computer-aided Manufacturing–guided Endodontic Surgery: Guided Osteotomy and Apex Localization in a Mandibular Molar with a Thick Buccal Bone Plate

A mandibular molar with a thick buccal bone plate is a challenging problem in endodontic surgery despite the increase in the success rate of endodontic surgery nowadays. This report describes the application of a surgical template to guide osteotomy and facilitate apex localization in a mandibular molar with a thick buccal bone plate. A 57-year-old woman visited the authors’ clinic for pain in tooth 19 and was diagnosed with symptomatic apical periodontitis in this previously treated tooth. Nonsurgical retreatment was performed; however, 2 years later, the patient reported pain in the same tooth. A periapical lesion was confirmed using cone-beam computed tomographic (CBCT) imaging, and endodontic surgery on the mesial root of tooth 19 was planned. After CBCT imaging and cast scan data were transferred to implant surgical planning software, the data were superimposed. In the superimposed model, an anchor pin was designed to target the mesial root apex of tooth 19. The surgical template was then printed using a 3-dimensional printer. Endodontic microsurgery included application of this printed surgical template. A computer-aided design/computer-aided manufacturing (CAD/CAM)-guided surgical template minimized the extent of osteotomy and enabled precise targeting of the apex in this case. There were no postoperative complications. A CAD/CAM-guided surgical template is useful in endodontic surgery for complicated cases.     

Ten-year follow-up of mandibular advancement devices for the management of snoring and sleep apnea

STATEMENT OF PROBLEM: Intraoral mandibular advancement devices have become widely used in recent years for the management of snoring and sleep apnea, and short-term effectiveness has been demonstrated. However, there is a shortage of data regarding long-term compliance. PURPOSE: The purpose of this study was to investigate the long-term compliance of patients who were provided with a mandibular advancement device. MATERIAL AND METHODS: Records of 180 patients who were provided with a mandibular advancement device in 1996 were available for review. A questionnaire was sent to all of these patients inquiring about continued device usage, comfort, and effectiveness. Questions were also asked about smoking, alcohol consumption, height, and weight. Data were analyzed with chi-square tests for any association between these factors and success of the device (alpha=.05). RESULTS: The response rate was 40%, with 72 replies. Of this number, 34 patients were currently wearing the device every night, with a further 13 wearing the device for up to 6 nights per week. Thirty-one of the respondents who were wearing the device felt more refreshed on waking. The median body mass index (BMI) was 30, 8 were smokers, and 12 subjects drank more than 20 units of alcohol per week. Few adverse effects of the device were reported. CONCLUSIONS: The mandibular advancement device appears to be an effective long-term solution for a significant number of patients with problem snoring and also those with mild to moderate obstructive sleep apnea.