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Modern clinical protocols in implantology aim to reduce the duration and discomfort of the surgical phase while preserving excellent treatment results. The purpose of this study is to evaluate the clinical differences between impression stone pouring and impression digital pouring required for surgical guide fabrication in fully guided dental implant surgery. This study was conducted for partially edentulous patients with straightforward cases who did not require bone or soft tissue augmentation. Forty dental implants were installed in 14 patients (age range: 25-70 y) at the Dental Implant Unit, Oral and Maxillofacial Surgery Center, Gazi Alhariri Teaching Hospital, Medical City, Baghdad. The dental implants were guided into the most prosthetically suitable position using a surgical guide. Twenty of them were guided by conventional impression stone pouring to create the surgical guide, whereas the other 20 implants were installed using digital pouring for the dental impression to fabricate the surgical guide. The mean for impression stone pouring in regard to angular deviation of 4.33±3.435 degree, the depth difference was 1.29±0.90 mm and entry point deviation 0.99±0.84 mm. In contrast, the mean for digital pouring in regard to angular deviation of 3.34±2.10 degree, depth difference was 0.89±0.67 mm and entry point deviation was 0.83±0.61 mm. This study revealed that there was no significant difference between the 2 groups regarding all 3 variables at a P-value of 0.05. Neither biological nor mechanical complications occurred.

The evolution of virtual surgical planning (VSP) in the last 2 decades has led to improved precision and efficiency for orthognathic surgery, both pre- and intraoperatively. This study evaluates a single surgeon's experience with this technology over the past 6 years. Patients undergoing orthognathic surgery using VSP with the senior author between 2015 and 2021 were retrospectively reviewed. Virtual surgical planning -specific data including incidence of midline/cant correction, occlusal equilibration, serial splints, segmental osteotomies, and custom plates were recorded and analyzed. Sixty patients undergoing orthognathic surgery using simulated VSP in the study period were retrospectively reviewed. Mean age at time of surgery was 23.5±7.9 years. Forty-nine patients (81.7%) underwent LeFort I osteotomy combined with at least 1 additional procedure (eg,unilateral or bilateral sagittal split osteotomy, condylectomy, genioplasty, etc.). Twenty-six (43.3%) of patients in the studied cohort underwent maxillary midline correction, 30.0% required occlusal equilibration, 36.7% underwent maxillary molar cant correction, 30.0% underwent mandibular cant correction, and 21.7% required both maxillary and mandibular cant correction. Three patients required serial splinting, and 15 patients (25.0%) required modification of splint design. Custom plates were utilized in 15 patients (25.0%). This study demonstrates the utility of VSP in accurately detecting occlusal cants, asymmetry, and occlusal interferences. Virtual surgical planning also allows for a dynamic preoperative planning process, offering the surgeon a high degree of versatility in splint design, and the ability to fabricate multiple customized splints for each case. This is particularly useful in patients with limited or unpredictable soft tissue elasticity.

Real-time surgical navigation systems are important for preoperative planning and intraoperative navigation. Automatic preoperative multimodal data registration and postoperative spatial registration are extremely crucial in such surgical navigation systems. However, existing automatic multimodal data registration methods have extremely limited application scope due to the lack of accuracy and speed. In addition, the registration results obtained by existing methods are practically lacking and are rarely applied in clinics. To address the above issues, this paper proposes a novel real-time teeth registration algorithm with computed tomography (CT) data and optical tracking scanning data. The proposed method is based on the weighted iterative closest point (ICP) algorithm with 3 improvements: (1) the multilayer spherical point set is generated inside the laser scanning marker sphere, (2) the weight decreases from inside to outside layer by layer, and (3) the weight of the voxel center point set is combined with the CT data of the marker sphere. Specifically, the proposed iCP registration method can overcome the limitation of surface point set registration and tackle the problem of high surface deformity of laser scanning marker spheres. For the registration result of CT and scanning data, the authors employ the real-time spatial registration algorithm based on optical tracking to complete the navigation of the simulated surgical instruments on the multimodal fusion image. The experimental results show that the proposed ICP algorithm reduces the mean square error by 1 order of magnitude and that our method has strong practical value.

Orthognathic occlusal repositioning wafers could be constructed virtually and 3D printed. This paper assessed the accuracy of a suggested virtual model to the conventionally established Glasgow model surgery.Prospective study of the orthognathic surgery models digitally.Seven patients who received bi-maxillary orthognathic surgeries for correction of dentofacial deformities.The patients were clinically assessed and their cone beam cmputerized tomography (CBCT) studied. Model surgery of each patient was performed conventionally using face-bow and semi-adjustable articulator. Same plan was executed virtually using Mimics (Materialise, Leuven, Belgium) and 3Matic (Materialise, Leuven, Belgium). Conventionally fabricated acrylic wafers as well as 3D printed wafers were CBCT scanned with the casts reflecting the archived repositioning dictated by the wafers. Paired sample t test was performed to compare accuracy between intermediate and final occlusal repositioning wafers within conventional and virtual technique groups.The mean deviation in intermediate wafer group was 0.64 ± 0.33 mm; whereas the mean deviation in final wafer group was 0.53 ± 0.10 mm. Paired sample t test showed that there was no statistically significant difference in mean deviation between both groups ( P = 0.403).This virtual surgical wafer achieves a similar level of accuracy to the conventional Glasgow model surgery.

To evaluate the surgical accuracy of positioning the maxilla in patients with skeletal class II malocclusion using computer-aided design and computer-aided manufacturing (CAD/ CAM)-assisted orthognathic surgery.The samples consisted of 10 patients with skeletal class II malocclusion, whose cone-beam computed tomographys taken before and immediately after surgery were available and who underwent bimaxillary orthognathic surgery by a single surgeon using Le Fort I osteotomy and bilateral sagittal split ramus osteotomy at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, Seoul, South Korea between January 2018 and December 2019. After virtual surgical planning was performed using the FACEGIDE system (Korea), surgical cutting guides, intermediate splints, and custom-made titanium mini-plates were fabricated using CAD/CAM technique. Using 8 landmarks (anterior nasal spine, point A, #16, #13, contact point between #11 and #21, #23, #26, posterior nasal spine), the mean differences between the virtually planned (Virtual) and actual postsurgical position of the maxilla (Actual) in the three-dimensional coordinates (ΔActual-Virtual) and their mean absolute deviations were investigated.The mean differences of 8 landmarks were 0.42 mm left side movement in the transverse coordinate, 0.15 mm forward movement in the sagittal coordinate and 0.10 mm downward movement in the vertical coordinate. Their mean absolute deviations were 0.98, 0.67, and 0.62 mm in the sagittal, vertical, and transverse coordinates, respectively.Since the mean difference was less than 0.5 mm and the range of error was less than 1.0 mm, CAD/CAM-assisted orthognathic surgery might have a high degree of surgical accuracy and clinical relevance in the positioning of the maxilla.

To investigate current Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) technologies applied in the treatment of dentofacial deformities secondary to condylar osteochondroma and introduce a modified method with additional pre-bent titanium miniplates to improve the accuracy of operation.Literature review about the application of CAD/CAM in the treatment of condylar osteochondroma and secondary dentofacial deformities was conducted. And 8 patients with condylar osteochondroma and secondary dentofacial deformities were treated by the CAD/CAM cutting and drilling surgical guides as well as pre-bent titanium miniplates. Pre- and post-operative 3D-cephalometric measurement were recorded and the difference between virtual simulation and postoperative modeling images was measured. Follow-up and radiographic examinations were performed.A total of 17 studies (including 216 patients) about the application of CAD/CAM in the treatment of dentofacial deformities secondary to condylar osteochondroma have been reported since 2010, including the 8 present patients. In our study, all patients were satisfied with the surgical outcome, without obvious relapse or evidence of temporomandibular joint disorder or other complications during follow-up; all patients avoided condylar reconstruction and sagittal split of ramus osteotomy on the ipsilateral mandible side. Comparison between simulated plans and actual postoperative outcomes showed surgical simulation plan was accurately transferred to the actual surgery.The application of CAD/CAM cutting and drilling guides as well as pre-bent titanium plates could achieve more accurate and favorable outcomes, improving the clinical planning and surgical execution for patients with condylar osteochondroma and secondary dentofacial deformities.

In order to reduce the possibility of accidental injury to neurovascular and important tissues, this research conduct preoperative design and intraoperative guidance for fibrous dysplasia through augmented reality technology.Five patients with fibrous dysplasia were selected for three-dimensional (3D) Computed Tomography (CT) scan and 3D model was reconstructed. Considering the navigation plan was comprehensively, the guide plate (composed of card groove, connector, and fixator) was designed and 3D printed. Threedimensional software was used to unify the coordinates of the surgical plan and the guide plate, and the relative position was fixed. Then, the virtual and real overlapping registration is completed on the physical model. Pattern recognition technology is used to identify pre-defined markers in the video images before operation. Finally, the registration results are superimposed into the surgical field of vision to guide and remind surgeons.In this study, the navigation based on augmented reality technology was used in the surgical treatment of 5 cases patients with fibrous dysplasia. The 3D navigation information was displayed in real time in the operative field. The operation was accurate and the postoperative effect was good.This paper introduces an effective visual navigation surgical method in treatment with fibrous dysplasia. The augmented- reality based navigation system achieves individualized precise treatment by displaying 3D navigation directly in the surgical field. It is an effective auxiliary method for future research on craniofacial surgery.

To evaluate the accuracy of intentional change of the frontal ramal inclination (FRI) from virtual to actual orthognathic surgery.A total of 16 patients who underwent orthognathic surgery for correction of facial asymmetry and took cone-beam computed tomography 2 to 3 weeks before surgery (T0) and 3 days after surgery (T1A) were selected. After reorientation of cone-beam computed tomography, the digital imaging and communications in medicine data was converted to StereoLithography format for the merging with dental cast scan using R2GATE software (MegaGen Implant, Daegu, Republic of Korea). During virtual surgery using Geomagic Freeform Plus software (3D Systems, Rock Hill, SC), bilateral FRI discrepancy was corrected (T1V) and 3D-printed surgical wafers and customized metal plates were manufactured using 3D printer (Meg-printer II, MegaGen Implant, Daegu, Republic of Korea) and computer numerical control milling machine (ARDEN, TPS Korea Ltd., Gwangju, Republic of Korea) accordingly. During surgery, FRI correction was done using surgical guide and customized plates. The difference between preoperative and virtually corrected FRI (Δ T1V - T0) and the difference between preoperative and actually surgically corrected FRI (Δ T1A - T0) were measured, and the achieved FRI correction in percentage ([Δ T1A - T0]/[Δ T1V - T0] × 100) was calculated.The mean absolute value of virtual FRI correction (Δ T1V - T0) and actual FRI correction (Δ T1A - T0) were 3.0° and 2.9°, respectively (n = 32). In the increased (medial rotation) FRI group, mean virtual and actual correction amount were 3.2° and 2.8° (n = 17), whereas in the decreased (lateral rotation) group, mean virtual and actual correction amount were -2.7° and -3.1°, respectively (n = 15). No statistically significant difference between virtual and actual measurements were present in either group. The mean achievement rate was 102.8%. Tendency of undercorrection (91.2%) in the increased FRI group and overcorrection (116.0%) in the decreased FRI group were noted.With virtual planning and computer-aided design and computer-aided manufacturing-made customized plates, it is possible to correct FRI during orthognathic surgery of patients with facial asymmetry.

BACKGROUND The fibula free flap is a major workhorse in facial reconstruction. To decrease operative times, virtual surgical planning (VSP) has been implemented. Traditional VSP is costly and may delay operative planning. In this study, the authors present a novel algorithm using readily accessible software packages to perform VSP in a manner that is quick and cost-effective. METHODS A 6-part survey was administered to physicians with prior training in facial reconstruction. Fourteen physicians participated regarding outcomes on 10 patients who underwent mandibular or midfacial fibula free flap reconstruction. Participants were asked to match the true postoperative and VSP models and rate the similarity of the models using the Likert scale (0-10). The goal was to determine whether the VSP models accurately depicted the actual reconstruction, and whether they would use VSP in future clinical practice. RESULTS The physicians surveyed were able to match the models correctly 93.6% of the time. The mean score for the similarity between virtual and actual models ranged between 7.60 and 8.80. Most participants (90.9%) who answered stated they would use our VSP algorithm if they were trained in the protocol. CONCLUSIONS AND RELEVANCE Virtual surgical planning models were created utilizing our novel algorithm. Participants matched the preoperative VSP plan with the postoperative model most of the time and rated the similarity well. Participants in our study are interested in learning more about physician performed VSP. The authors believe this model may be financially and clinically relevant and serve as an excellent educational tool.

BACKGROUND Augmented reality (AR) is an imaging technology encompassing an interactive experience of a real-world environment enhanced by computer-generated perceptual information. It has been introduced to current medical practice to help the preoperative planning in many surgical fields. METHODS The authors applied AR to the computed tomography angiography of 8 patient's legs. Computed tomography angiography images were processed into Digital Imaging and Communications in Medicine files to make a prefabricated cutting guide and customized titanium plate. Also, three-dimensional reconstruction of the arterial supply of the leg was performed to identify the perforators. RESULTS Followed by preoperative marking of operative details on patient's skins in antero-posterior view, lateral view, and combination of both views. Inaccuracy of measurement was confirmed by duplex ultrasound which average error of the combination of antero-posterior and lateral viewed of both legs was lowest (0.7 ± 0.2 cm). Followed by lateral view (1.0 ± 0.3 cm) and antero-posterior view (1.2 ± 0.4 cm), respectively. CONCLUSIONS Augmented reality can improve patient's safety by directly locate the perforator and easily to design the skin paddle. Followed by satisfaction and confidence in patients and their relatives. Augmented reality also promoted understanding of operative steps for related assistants, residents, or fellows. Augmented reality can perform with existing equipment, mobile phone application, and can save the cost for preoperative planning. Distortion in the depth view can be more accurate by combining of AR in antero-posterior and lateral view.

Background An augmented reality tool allows visual tracking of real anatomical structures and superimposing virtual images, so it can be used for navigation of important structures during surgery. Objectives The authors have developed a new occlusal splint-based optical navigation system for craniomaxillofacial surgery. In this study, the authors aim to measure the accuracy of the system and further analyze the main factors influencing precision. Methods Ten beagle dogs were selected and a three-dimensional model was established through computed tomography scanning, dental model making, and laser scanning, and then registration was performed according to the tooth marking points. The bilateral mandibular osteotomy was performed on Beagle dogs under navigation system based on the occlusal splint. The left side was taken to compare the deviation between the preoperative plan and the surgical results, and the accuracy of distance and angle and the stability of the system were analyzed. Results The average position deviation between the preoperative design and intraoperative navigation was: 0.01 ± 0.73 mm on the lateral height of the mandibular ramus, 0.26 ± 0.57 mm on the inner height of the mandibular ramus, and 0.20 ± 0.51 mm on the osteotomy length. The average angle deviation is 0.94° ± 1.38° on the angle between the mandibular osteotomy plane and ramus plane and 0.66° ± 0.97° on the angle of the retained mandibular angle. And most of the data showed good consistency. Conclusions In summary, the accuracy of the system can meet clinical requirements and can be used as a useful tool to improve the accuracy of craniomaxillofacial surgery.

Craniofacial fibrous dysplasia is a slow-growing bony disorder causing asymmetry of the face; leading to aesthetic, functional, and psychological ramifications. Surgical recontouring is the most accepted form of treatment. Reconstruction of the orbit poses a serious challenge to the surgeon; hence the present study is intended to describe and evaluate a most anatomically accurate virtual treatment planning and defect-specific implant technique, enumerating postoperative functional and esthetic outcome. The study highlights a valid application of three-dimensional models and computer-guided surgical splints. The current study included 5 patients with craniofacial fibrous dysplasia involving orbits with a mean age of 19.6 years. Detailed pre- and post-operative ophthalmologic workup were documented for one year. All the participants showed improvement in eyeball position and movement. Visual acuity and intraocular pressure have returned to near normal values, and astigmatism was reduced significantly. No recurrence was noted in any of the subjects. The current technique was found helpful in reconstructing the complex orbital anatomy; however, long-term follow-up studies with a greater number of patients are recommended.

This is a retrospective study to evaluate the postsurgical position of the maxilla and mandible in 5 matured craniofacial patients with unilateral craniofacial microsomia who underwent 2 jaw surgical procedures using computerized surgical planning. The craniofacial surgeon and orthodontist completed the virtual surgical treatment plan with a biomedical engineer's assistance via a web meeting. The treatment plan of each patient included 2 jaw surgery with genioplasty. At the maxillary dental midline, the planned mean advancement was 4 mm; yaw, a rotational correction towards the unaffected side was 4.96 mm; and impaction was 2.74 mm. The mean advancement measured at point B was 10.5 mm, and the rotational correction towards the unaffected side was 6.58 mm. The mean advancement following genioplasty was 8.43 mm, and the mean transverse correction was 6.33 mm towards the midsagittal plane. The intermediate surgical splint, final surgical splint, bone graft templates, and cutting guides were constructed utilizing computer-aided design/computer-aided manufacturing technology. The surgeon executed the treatment plan in the operating room using appropriate computer-generated guides and splints. A postsurgical cone-beam computed tomography scan was obtained and superimposed on the surgical treatment plan using Simplant OMS 10.1 software. The cranial base was used as a reference for superimposition. Three-dimensional color-coded displacement maps were generated to visually and quantitatively assess the surgical outcome. There was a mean error of 0.88 mm (+0.30) for the position of the maxillary anatomical structures from the planned position, and the anterior mandibular anatomical structures were on average 0.96 mm (+0.26) from the planned position.

Intraosseous benign lesions rarely involve the zygoma, and intraosseous venous malformation is most commonly reported condition in the previous literature. A neurofibroma (NF) arising from the zygoma has not been reported before. Here, the authors present a 37-year-old female who developed solitary NF of the right zygoma. Surgical intervention is usually required for the treatment of a solitary NF. However, the complex three-dimensional (3D) anatomy of the zygoma increases the difficulty of the reconstruction for the operating surgeon. In this case, a preoperative digital surgical design was used to promote the efficiency of the surgery. A 3D printing surgical guide plate was used intraoperatively, and the defect was reconstructed by a patient-specific polyetheretherketone implant. Postoperative computed tomography imaging confirmed the accuracy of the reconstruction and that there was no recurrence of the tumor. The authors believe that the 3D print guide plate-assisted accurate resection combined with polyetheretherketone implant reconstruction is an ideal methodology for benign lesions of the zygoma.

Objective The purpose of this study is to propose a surgical plan based on augmented reality (AR) and guide template technology for restoration of nasal deformities, and evaluate its feasibility and clinical efficacy. Methods Patients were scanned with a FaceScan to obtain the three-dimensional (3D) facial model, and computed tomography was also performed to obtain the maxillofacial computed tomography images while wearing the artificial marker. The mirroring tool and database searching and matching technology were employed to restore the nasal deformities for a normal nose (preoperative planning model). The design of guide template for deciding the incision area was based on the preoperative planning model, which was also imported into the AR image guidance system named HuaxiAR1.0 for reconstruction of the nose contour. One week after the surgery, the postoperative 3D facial model was obtained. Then, the clinical efficacy was evaluated by comparing the difference between the preoperative planning and postoperative 3D facial model. Results The patients obtained satisfactory nasal shapes after surgery. Comparison of the difference between the preoperative and postoperative 3D model revealed that the maximum error was ranging from 2.24 mm to 3.10 mm with the mean error from 0.54 mm to 0.65 mm. Conclusion The combined application of AR and guide template technology provides a new approach for the treatment of nasal deformities, and has a certain significance in realizing the precise repair of other craniofacial soft tissue deformities.

Surgical navigation has greatly improved the accuracy of craniomaxillofacial bone surgery and is widely used in the clinic. However, during surgery, craniomaxillofacial soft tissue is always deformed due to traction and compression, which leads to intraoperative image drift. This, in turn, impacts navigation accuracy. In order to improve navigation accuracy, this technical note presents a preliminary proposal for fusion imaging technology, which combines ultrasound and computed tomography to address navigational image drift in craniomaxillofacial soft tissue surgery.

Orbital reconstruction has traditionally been accomplished utilizing different techniques developed for this purpose and has been modified and improved throughout the years. However, there is a high rate of complications associated with eye globe positioning and/or migration of implants, which has created the need to continue to improve these techniques to decrease the frequency of complications. On the other hand, techniques that involve an endoscopic approach and technologies that use virtual surgical planning and three-dimensional model impressions are being used more often to decrease complication rates and seek better surgical outcomes. Combining these 2 methods results in endoscopically integrated virtual surgical navigation. When used for orbital reconstruction, it can be a great alternative and can be useful to decrease the risk of complications associated with this procedure. Therefore, this technical note aims to describe the integration of these 2 techniques into the same instrument to demonstrate the synergy of their benefits when used together.

OBJECTIVE To assess the use of custom-made intracranial implants and three-dimensional cutting guides to direct the intracranial, intraorbital, and temporal reconstruction process for intraosseous meningioma. METHODS A retrospective analysis was conducted on 6 patients who were operated on by the senior author for intraosseous meningioma between 2017 and 2020. Three-dimensional models of the maxillofacial skeleton were created from preoperative virtual planned reconstruction and postoperative computed tomography scan images in the Mimics and 3-Matics software. Orbital reconstruction and temporal implant accuracy assessments were performed through the Materialise Mimics software. RESULTS Orbital cone volume had a mean discrepancy between the planned and actual orbital volume of 1.5% ± 1.6%. The reconstructed postoperative orbital volume was within 1.3% ± 2.0% of the unaffected orbit. Temporal bone reconstructions had a mean implant accuracy of 81.0%. CONCLUSIONS Our results show that the postextirpative intracranial applications of virtual surgical planning are particularly suited for high fidelity reconstructions such as orbital reconstructions, as well as temporal reconstructions with intraoperative adjustments. Custom implants and virtual three-dimensional planning is particularly ideal and promising for intraosseous meningiomas given the involvement of complex intracranial and intraorbital bony structures.

Objective Surgical navigation-guided removal of foreign bodies in the craniomaxillofacial region has been proven to be an effective method. However, there have been some unsuccessful patients due to reduced navigation accuracy or complicated and undetectable anatomy. This article summarizes the experience and proposes some solutions to achieve better results. Study design Two solutions were proposed to optimize the surgical navigation procedure: using a 3-dimensionally printed customized mandible retainer to indirectly maintain the consistency of the foreign body's visual images of preoperative planning and intraoperative navigation and importing real-time endoscopic imaging during surgery to provide vision under complex anatomy. Two patients were selected for each method. Results The foreign bodies were successfully and minimally invasively removed in all patients assisted by optimized surgical navigation. During follow-up at 3 to 6 months postoperatively, no complications were found. Conclusion Improving navigation accuracy and providing real vision might be effective at compensating for insufficient navigation due to navigation positioning errors or the interference of imperceptible and complicated anatomy.

INTRODUCTION While the use of virtual surgical planning (VSP) has been well described in the adult craniofacial literature, there has been little written about pediatric uses or trends. The purpose of this study is to evaluate the evolving utilization of VSP for pediatric craniofacial procedures. METHODS The authors' prospective institutional review board-approved craniofacial registry was queried for index craniofacial procedures from January 2011 through December 2018. Data was collected regarding utilization of traditional surgical planning versus VSP, as well as the extent of VSP's influence on the operative procedure. These data were analyzed for trends over time and compared using appropriate statistics. RESULTS During the study period, a total of 1131 index craniofacial cases were performed, of which 160 cases (14.1%) utilized VSP. Utilization of VSP collectively increased over time, from 2.0% in 2011 to 18.6% in 2018 (P

Computer-aided surgery has been widely used in treatment of hemifacial microsomia and matured in recent decades. These techniques include the computer-aided design, virtual surgical planning, modeling surgery, rapid prototyping techniques, intraoperative navigation and so on. The purpose of this article is to summarize the current application of computer-aided design/computer-aided manufacturing technology in the treatment for hemifacial microsomia during the last 5 years, as well as the views and discussions on some topics, and finally introduce a method of our team. Our effort is that using the holes predrilled in cutting guides, the pre-bent titanium plates are easily placed. Avoiding potential bone autorotation caused by unfitness between conventional titanium plates and bone surface, which keeps the bone fixation precisely in line with the preoperative virtual plan and reduce the movement of bone segments due to the undesirable stress of the plates.

Unicoronal craniosynostosis is the second most common type of nonsyndromic craniosynostosis: it is characterized by ipsilateral forehead and fronto-parietal region flattening with contralateral compensatory bossing. It is a complex condition; therefore, which is difficult to treat because of the asymmetry in the orbits, cranium, and face. The aim of this study is to understand optimal osteotomy locations, dimensions, and force requirements for surgical operations of unicoronal craniosynostosis using a patient-specific finite element model and - at the same time - to evaluate the potential application of a new device made from Nitinol which was developed to expand the affected side of a unicoronal craniosynostosis skull without performing osteotomies. The model geometry was reconstructed using Simpleware ScanIP. The bone and sutures were modeled using elastic properties to perform the finite element analyses in MSc Marc software. The simulation results showed that expanding the cranium without osteotomy requires a significant amount of force. Therefore, expansion of the cranium achieved by Nitinol devices may not be sufficient to correct the deformity. Moreover, the size and locations of the osteotomies are crucial for an optimal outcome from surgical operations in unicoronal craniosynostosis.

Optical navigation method cannot be used in partial craniofacial surgery due to light blocking. At present, electromagnetic navigation method can be used instead. The occlusal splint obtained from the patient's dental mold is used in the traditional electromagnetic navigation registration. Then, marker points are selected manually for registration through imaging data during the operation, which leads to the deviation of selection. In this study, the self-developed registration software was used to perform automatic registration in the intraoperative registration. Experimental results showed that it has higher accuracy and faster speed, and is suitable for the actual operation process in clinical environment compared with the traditional manual registration.

Objective The purpose of this study was to evaluate the use of a modified template system and double computed tomography scan procedure to maintain mandibular width in cases of mandibular reconstruction. Study design Ten patients who underwent mandibular reconstruction with a fibular flap were enrolled. The surgeries were planned with a computer-aided surgical simulation (CASS) planning method. Following double computed tomography scan procedure, the template system was designed in a computer and was fabricated using a three-dimensional printing technique. The cutting guides were designed with the holes of the conventional reconstruction plate on the remnant mandibular segments. After surgery, the outcome evaluation was compared by first superimposing the post-operative computed tomography model onto the planned model and then measuring the differences between the planned and actual outcomes. Results All surgeries were completed successfully using the template system. With the use of the templates, the largest linear root-mean-square deviation (RMSD) between the planned and post-operative remnant segments was 1.01 mm, and the largest angular RMSD was 4.05°. Conclusions The authors conclude that this template system and double computed tomography scan procedure provides a reliable method to maintain mandibular width in mandibular reconstruction using a fibular flap.

Purpose Try to apply augmented reality (AR) technique which based on visual recognition artificial marks in the treatment of unilateral Orbitozygomatic Maxillary complex fractures (OZMF), and to explore the feasibility and the application value of the AR for assisting the oral and maxillofacial surgery (OMFS) treatment. Methods Based on the AR application JSARToolKit developed on the web, and combining with the self-designed tooth-borne type visual recognition artificial marks to display three-dimensional (3D) image of the region of interest (ROI), virtually designed the position and direction of plate on the jaw and helped OZMF surgery. According to some results to evaluate the postoperative effects, such as imaging, occlusion, facial appearance recovery, patients' satisfaction and operation time. Results The AR achieved the 3D image of ROI in real time, satisfied information enhancement of real scene, broadened the surgeon's horizons and improved the 3D recognition ability of maxillofacial tissue. After operation, patients had no discomforts, fracture reduction were well healed through imaging examination, and the titanium plate position was consistent with the preoperative planning. What is more, patients' facial appearance and occlusal function recovered well, significantly shorten the intraoperation time. Conclusion Augmented reality technology is an effective method for OZMF treatment but there are still many technical difficulties which need to be get over, and its application in maxillofacial surgery and relevant basic theories are both worth further exploring.

Purpose The direction and orientation of the osteotomized upper segments in dental implant distractor (DID) can be compromised due to an unpredicted vector of distraction. The present study aimed to evaluate the accuracy of computer-aided design/computer-aided manufacturing (CAD/CAM) surgical templates to precisely guide the distraction process in lengthening of the alveolar height for functional mandibular reconstruction. Patients and methods This retrospective study included all consecutive patients who underwent digitally designed mandibular reconstruction using the fibular flap and DID with the help of CAD/CAM designed surgical templates in a single-stage procedure from 2011 to 2014. First, the preoperative digital planning was performed on 3-dimensional models. Afterward, simulation of the distraction process was made on the virtual model and the resulting new height of the fibula was evaluated. The preoperative simulation was applied to accurately define the exact location and path of the DID device to achieve the suitable vertical height. The preoperative digital planning was used to help the design of the CAD/CAM surgical template, which was then fabricated by means of the 3-dimensional printing technology. The manufactured surgical template-assisted both horizontal and vertical osteotomies of the fibular segments and defining the DID path to lead the distractor into the accurate position. The outcome evaluation was achieved through comparing both preoperative virtual planning with postoperative actual outcomes. Results This study included 14 subjects, 8 were males and 6 were females. The mean age at time of surgery was 31.07 years (range 18-47). All fibular flaps showed 100% success rate. The mean vertical bone height attained with the DID device was 11.35 mm. The vertical and horizontal osteotomies of the fibular segments were completed, then the DID devices were successfully positioned guided by the template. The mean values of the linear and angular deviations for the distractor position and upper segments were calculated and recorded. The maximum linear deviation between the virtual and the postoperative actual distractors was 0.93 mm in the anteroposterior direction, and the greatest in the horizontal plane was 4.64°. Conclusions CAD/CAM surgical templates can accurately guide the direction and orientation of the DID device for functional mandibular reconstruction; therefore, helping to improve the outcomes by accurately transferring the preoperative virtual plan to real surgical procedure.

Background The recent increase in computer-aided design and computer-aided manufacturing (CAD/CAM)-assisted surgery has warranted a thorough evaluation of the accuracy of virtual plan execution. Mandibular reconstructions with a fibula free flap were evaluated by comparing the fibular segments postoperatively with the virtual surgical plans. Methods This study included computed tomography data for 20 patients (11 males; mean age 61.3 years, range 47-74) that received a mandibular reconstruction with a fibula free flap. Linear distances (superior and inferior borders) of 41 fibula segments and intercoronoid distances were measured. Results The mean difference was 3.11 ± 2.80 mm for superior borders (range 0.02-12.20 mm), and 2.75 ± 2.61 mm for inferior borders (range 0.22-13.58 mm). The mean intercoronoid difference was 3.57 ± 1.80 mm (range 0.91-6.11 mm). Conclusion This study confirmed the presumed accuracy regarding the use of fibular and mandibular cutting guides. CAD/CAM is an attractive technique which enhances efficiency and assurance during surgery and preoperative planning.

Anterior segmental osteotomy (ASO) is considered the treatment modality of choice in patients with the bimaxillary dentoalveolar protrusion. However, this meticulous surgical technique accompanies a number of possible disadvantages. The considerable time required before, during, and after the operation, limited movement of the segment, damage of the mental nerve, loss of tooth vitality, loss of a tooth or teeth, or indeed total loss of the anterior segments are those that affect the result of the surgery. Recently, the authors have devised a computer-aided surgical simulation programme and fabricated the customized osteotomy guides and the spider-shaped plates based on the programme. They were then applied to a 28-year-old patient with the complaint of a bimaxillary dentoalveolar protrusion. This approach helped to overcome several problems related to ASO reported earlier.

Mandible fracture is a common injury in maxillofacial surgery. It causes not only maxillofacial dysfunction but also facial deformities. Malunited fractures of the mandible have been a vast challenge in clinical treatment due to the misalignment of the broken ends and the occurrence of occlusal disorders. This case report describes using virtual surgical planning and three-dimensional printing to treat a patient with malunited fracture of the mandible. Failing to perform mandibular surgery due to severe brain trauma after the car accident, the patient got malunited healing of mandible. The authors applied virtual surgical planning to perform preoperative analysis and surgical design on this patient, three-dimensional printing to fabricate occlusal plate, and models of the preoperative and postoperative mandible to guide the operation. Finally, the authors achieved the reduction and reconstruction of the mandible with satisfactory clinical results.

The use of customized plates in Orthognathic surgery offers precision in the repositioning of the jaws, according to the virtual planning performed, with the great advantage of avoiding the need for intermediate occlusal splints. However, the conventional customization process takes time to manufacture, present high cost and still involve legal issues with insurance companies. Moreover, a technical disadvantage is that the systems available for customized plates require large incisions, with large detachment of soft tissues for insertion of the guides and plates. The objective of this paper is to present the in-house hybrid technique for customization of guides and miniplates in orthognathic surgery using minimally invasive approaches.

Fat grafting has become a well-accepted surgical modality to correct soft tissue facial defects and asymmetries with overall good results. Several techniques have been reported over the last few years to assist in improving accurate evaluation of facial defects and in the preoperative planning of the reconstruction. Such techniques include among others, computer tomography, three-dimensional (3D) photogrammetry, high resolution ultrasound, and 3D laser scanning. There are advantages and disadvantages for each technique.With the rapid advance of 3D technologies that have become readily available to clinicians, new clinical applications continually emerge to guide and facilitate reconstructive procedures. The authors explored the possibility of fabricating a 3D printed surgical guide to define volume differences for soft tissue reconstruction in patients with facial asymmetry. The model was developed through the authors' virtual surgical simulation and planning system that consists of computer-assisted design (CAD) and 3D printing (3DP).Three-dimensional volumetric scans of patients' faces were analyzed with computer-aided design to quantify areas of facial asymmetry. Surgical guides with containers defining volumetric differences were fabricated using 3D printing to identify and quantify areas of soft tissue deficiency. The 3D printed patient-specific, guides were sterilized and used by the surgeon intraoperatively to accurately mark the areas of soft deficiency. Thus, facial symmetry was achieved by fat grafting the predetermined volume differences defined in the surgical guides. A postop mask was used by the surgeon at the end of the procedure and during follow-up clinic visit to verify and evaluate accurate fat grafting placement as well as to determine areas where to add volume if needed.This paper details the rational for the authors' approach, outlines the technical planning and fabrication process of these patient-specific custom surgical guides with quantified volumetric containers and their intraoperative use by the surgeon. Despite the authors' limited experience we conclude that the authors' technique offer surgeons a precise means for accurate volumetric reconstruction of facial asymmetry.

Introduction Image-guided navigation has existed for nearly 3 decades, but its adoption to craniofacial surgery has been slow. A systematic review of the literature was performed to assess the current status of navigation in craniofacial surgery. Methods A Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) systematic review of the Medline and Web of Science databases was performed using a series of search terms related to Image-Guided Navigation and Craniofacial Surgery. Titles were then filtered for relevance and abstracts were reviewed for content. Single case reports were excluded as were animal, cadaver, and virtual data. Studies were categorized based on the type of study performed and graded using the Jadad scale and the Newcastle-Ottawa scales, when appropriate. Results A total of 2030 titles were returned by our search criteria. Of these, 518 abstracts were reviewed, 208 full papers were evaluated, and 104 manuscripts were ultimately included in the study. A single randomized controlled trial was identified (Jadad score 3), and 12 studies were identified as being case control or case cohort studies (Average Newcastle-Ottawa score 6.8) The most common application of intraoperative surgical navigation cited was orbital surgery (n = 36), followed by maxillary surgery (n = 19). Higher quality studies more commonly pertained to the orbit (6/13), and consistently show improved results. Conclusion Image guided surgical navigation improves outcomes in orbital reconstruction. Although image guided navigation has promise in many aspects of craniofacial surgery, current literature is lacking and future studies addressing this paucity of data are needed before universal adoption can be recommended.

Virtual surgical planning (VSP) has revolutionized the planning process in the reconstruction of the mandible with a free fibula flap. The traditional planning and design use a triangular osteotomy guide with a closing wedge movement at the angle. With virtual surgical planning, the authors found an additional lateral mandibular tilt angle and tried to incorporate it in our design of osteotomy guide. The authors have proposed a novel design in a trapezoid shape to accommodate the lateral tilt angle in our osteotomy design. Incorporating the two angles in one angle design improves the aesthesis of the reconstructive procedure and saves operative time.

OBJECTIVE Tumor resection and reconstruction as a one-step procedure requires accurate definition of the intended safety margins, precise location of osteotomy lines and reliable individual rehabilitation.In recent years, the role of image-guided surgery in the maxillofacial region has increased significantly. As this technology allows the surgeon to track the actual position of each instrument during the operation in real-time, it makes it possible to perform extensive bone structure resections and reconstructions in anatomically distorted or complex areas, such as the head and neck region, without unnecessarily damaging vital structures.The authors described a case of a 26-year-old woman presented to our Clinic with an extensive maxillary squamous cell carcinoma involving the infratemporal fossa. The patient underwent single-step navigation-guided en bloc resection of the tumor and defect reconstruction.The aim of this study is describe and discuss the unusual surgical planning and the challenging operative technique adding a new case to the currently limited scientific literature on the computer-assisted head and neck oncologic surgery.

Background In orthognathic surgery, virtual surgical planning (VSP) is gaining popularity over traditional surgical planning (TSP); however, concerns about cost of VSP have slowed adoption of this technology. This study investigates the clinical value of VSP versus TSP over the entire clinical care continuum. Methods Retrospective cohort study was conducted for patients undergoing maxillomandibular surgery between 2005 and 2016 at a tertiary pediatric hospital. Clinical value, defined as patient outcomes per unit cost, was analyzed between the 2 groups with appropriate statistics. Results The VSP (n = 19) and TSP (n = 10) cohorts had statistically similar hospital lengths of stay, rates of complications, readmissions, and duration of postoperative orthodontic treatment (P = 0.518, P > 0.999, P > 0.999, P = 0.812, respectively). VSP maxillomandibular procedures trended towards shorter operative times (P = 0.052). Total hospital charges were statistically similar between the TSP and VSP cohorts (P = 0.160). Medication, laboratory and testing, and room charges were also statistically similar between the TSP and VSP cohorts (P = 0.169, P = 0.953, and P = 0.196 respectively). Conclusions Indexed patient outcomes and costs incurred for maxillomandibular procedures were statistically similar between those utilizing TSP or VSP leading us to conclude that these 2 methods are associated with similar clinical value. This retrospective analysis should be followed with prospective data to give patients and insurers the best estimate of clinical value utilizing TSP and VSP.

Objective This article describes a virtual protocol designed to optimize surgical orthodontic diagnosis and treatment plan. Methods A total of 15 patients undergoing orthodontic-surgical treatment have been analyzed with a presurgical virtual three-dimensional (3D) treatment planning, which involves 9 steps. All the patients have been treated with the use of occlusal splint guides projected on the basis of the surgical and orthodontic visualized treatment objective . Results In all the analyzed patients, a precise and optimal orthodontic presurgical preparation has been obtained. Conclusions The 3D analysis seems more precise to interpret than two-dimensional; it provides information and images of craniofacial structures free from perspective distortion and it reduces the steps of the presurgical diagnosis. The simplicity of the protocol described in this paper makes possible to apply it in everyday practice.The study described here allows high-precision planning of orthodontic-surgical therapy and optimization of each treatment phase, with consequent advantages in clinical practice: a more accurate orthognathic surgery with predictable results.

Background Late treatment of scaphocephaly presents challenges including need for more complex surgery to achieve desired head shape. Virtual surgical planning for total vault reconstruction may mitigate some of these challenges, but has not been studied in this unique and complex clinical setting. Methods A retrospective chart review was conducted for patients with scaphocephaly who presented to our institution between 2000 and 2014. Patients presenting aged 12 months or older who underwent virtual surgical planning-assisted cranial vault reconstruction were included. Patient demographic, intraoperative data, and postoperative outcomes were recorded. Pre- and postoperative anthropometric measurements were obtained to document the fronto-occipital (FO) and biparietal (BP) distance and calculate cephalic index (CI). Virtual surgical planning predicted, and actual postoperative anthropometric measurements were compared. Results Five patients were identified who fulfilled inclusion criteria. The mean age was 50.6 months. One patient demonstrated signs of elevated intracranial pressure preoperatively. Postoperatively, all but one needed no revisional surgery (Whitaker score of 1). No patient demonstrated postoperative evidence of bony defects, bossing, or suture restenosis. The mean preoperative, simulated, and actual postoperative FO length was 190.3, 182, and 184.3 mm, respectively. The mean preoperative, simulated, and actual postoperative BP length was 129, 130.7, and 131 mm, respectively. The mean preoperative, simulated, and actual postoperative CI was 66, 72, and 71.3, respectively. Conclusions Based on our early experience, virtual surgical planning using a modified Melbourne technique for total vault remodeling achieves good results in the management of late presenting scaphocephaly.

Introduction Craniosynostosis, the premature fusion of ≥1 cranial sutures, is the leading cause of pediatric skull deformities, affecting 1 of every 2000 to 2500 live births worldwide. Technologies used for the management of craniofacial conditions, specifically in craniosynostosis, have been advancing dramatically. This article highlights the most recent technological advances in craniosynostosis surgery through a systematic review of the literature. Methods A systematic electronic search was performed using the PubMed database. Search terms used were "craniosynostosis" AND "technology" OR "innovation" OR "novel.' Two independent reviewers subsequently reviewed the resultant articles based on strict inclusion and exclusion criteria. Selected manuscripts deemed novel by the senior authors were grouped by procedure categories. Results Following review of the PubMed database, 28 of 536 articles were retained. Of the 28 articles, 20 articles consisting of 21 technologies were deemed as being novel by the senior authors. The technologies were categorized as diagnostic imaging (n = 6), surgical planning (n = 4), cranial vault evaluation (n = 4), machine learning (n = 3), ultrasound pinning (n = 3), and near-infrared spectroscopy (n = 1). Conclusion Multiple technological advances have impacted the treatment of craniosynostosis. These innovations include improvement in diagnosis and objective measurement of craniosynostosis, preoperative planning, intraoperative procedures, communication between both surgeons and patients, and surgical education.

To introduce the surgical techniques and evaluate the effect of alloplastic total temporomandibular joint (TMJ) replacement aided by digital templates in giant condylar osteoma.Three patients with giant condylar osteoma were enrolled in this study. The maximal mouth opening was 1.9 cm on average. All the patients were underwent the computed tomography scan (slice thickness 1 mm) and the data were imported to Proplan 1.3 software for 3-dimensional bony segmentation and reconstruction. Osteotomy line and digital template according the 3-dimensional measurement were designed. All the joints were replaced with Biomet standard prosthesis under general anesthesia.All the operations were successfully performed. The follow-up period was from 6 to 18 months (average, 12 months). Pain relief of the joint and mouth-opening improvement were significant in 3 patients. No infection or loosening the prostheses was occurred. The occlusal relationship kept stable in all patients.Total TMJ replacement with standard prosthesis is a good strategy for TMJ reconstruction after giant condylar osteoma excision. The joint pain and the mouth-opening limitation resulted from giant condylar osteoma were markedly improved. Long-term effect remains to be evaluated based on a long-term follow-up.

Objective The aim of the study was to explore the values and disadvantages of micromirror in the intracranial aneurysm clipping surgery. Methods Micromirror was used to assist microsurgical clipping to 36 intracranial aneurysms in 31 patients, of which 3 were carotid-ophthalmic artery aneurysms, 3 were anterior choroidal artery aneurysms, 11 were posterior communicating artery aneurysms, 7 were middle cerebral artery aneurysms, 10 were anterior communicating artery or anterior cerebral artery aneurysms, and the rest were a posterior cerebral artery aneurysm and a posterior inferior cerebellar artery aneurysm. The micromirror was used before and after clipping to observe the anatomic features of necks hidden behind and medial to aneurysms, to visualize surrounding neurovascular structures, and to verify the optimal clipping position. Intraoperative indocyanine green fluorescein angiography, postoperative computerized tomography angiography, and digital subtraction angiography confirmed the success of sufficient clipping. Results Intraoperative indocyanine green angiography, postoperative computerized tomography angiography , or digital subtraction angiography were performed and showed no case of wrong or insufficient clipping of aneurysm. Conclusions Micromirror-assisted microsurgical clipping to the intracranial aneurysm is safe, sufficient, convenient, and practical.

Current approaches to orbit reconstruction are based on the assumption of facial symmetry and surgeons' experiences, and the reconstructed orbits are not precise. Through computer-assisted volumetric quantitative analysis, the volume of the bony orbit, and the volume of the soft tissues in both the anophthalmic orbit and the contralateral orbit are calculated in 39 anophthalmic patients. The rib graft is used for orbit reconstruction; the dosalis pedis flap and lipo-injection were used for soft tissue reconstruction and skin socket reconstruction. The size and the shape of the rib graft and soft tissues were designed according to the volumetric analysis. The size and the shape of the skin socket were designed according to measurement during surgery. Asymmetry eye sockets with adequate size were created in the 37 patients. Two patients presented with a poor asymmetry with the contralateral orbit, and got gradual extrusion of the eye prosthesis 4 months after operation, which was because of necrosis of the flaps. The flaps were remedied by frontal island flap and skin grafting. Further surgeries, such as lipoinjection, lid surgery, and canthoplasty, were applied to improve the surgical results. The eye prostheses fitted well in all of the reconstructed sockets using this technique. Our studies suggest that the computer-assisted volumetric analysis technique combined with quantitative bone graft and dorsalis pedis flap transfer, ± lipoinjection proved to be an accurate method and a quality assurance for optimization of bony orbit, soft tissue and skin socket reconstruction, and promised a successful postoperative outcome for patients' functional and esthetic appearance.

Although free fibula flaps are widely used for mandibular reconstruction, 3-dimensional (3D) position is difficult to control in angle-to-angle mandibular defects. The present study describes a revised approach for angle-to-angle mandibular reconstruction with fibula flaps by using mandibular fixation device and surgical navigation.Preoperative maxillofacial and fibular computed tomography (CT) scans were acquired, and CT data were imported into ProPlan CMF software. Virtual mandibulectomy was performed, and 3D fibula image was superimposed on the mandibular defect. The fibula flap was shaped according to virtual parameters and the stereo model. Surgical navigation was used to check and correct shaped segments. Position of the osteotomy lines and relevant parameters regarding the shape of the fibula flap were provided to the surgeon. A mandibular fixation device (Cibei, China) was fixed to bilateral mandibular ramus before mandibulectomy, which maintained normal mandibular width. Under computer navigation guidance, the fibula flap was accurately positioned in 3D direction, and the defect could be precisely reconstructed despite the lack of stable occlusal relationship after osteotomy.Postoperative CT and 3D error analysis revealed that osteotomy lines and reconstruction contour matched well with preoperative planning. Using our method, we precisely recovered the original configuration of the mandible. Bilateral condyles were located in the temporomandibular joint fossae, and normal mandibular width was maintained. Compared with preoperative positions, the average shift on the remaining mandible was 0.803 ± 0.502 mm (largest, 1.886 mm). Average shift in the reconstructed mandible was 0.281 ± 0.300 mm, largest being 2.441 mm.We describe a novel method for angle-to-angle mandibular reconstruction with free fibula flap. A mandibular fixation device combined with computer-assisted techniques involving surgical navigation improved clinical outcomes of this procedure.

Rationale and aim Hemimandibular hyperplasia is characterized by an obvious overgrowth in the size of the mandible on one side, which can extend up to the midline causing facial asymmetry. Surgical resection of the overgrowth depends heavily on the skill and experience of the surgeon. This report describes a novel methodology of applying three-dimensional computer-aided-design and computer-aided-manufacturing principles in improving the outcome of surgery in 2 mandibular hyperplasia patients. Methodology Both patients had their cone beam computer tomography (CBCT) scan performed. CMF Pro Plan software (v. 2.1) was used to process the scan data into virtual 3-dimensional models of the maxilla and mandible. Head tilt was adjusted manually by following horizontal reference. Facial asymmetry secondary to mandibular hypertrophy was obvious on frontal and lateral views. Simulation functions were followed including mirror imaging of the unaffected mandibular side into the hyperplastic side and position was optimized by translation and orientation functions. Reconstruction of virtual symmetry was assessed and checked by running 3-dimensional measurements. Then, subtraction functions were used to create a 3-dimensional template defining the outline of the lower mandibular osteotomy needed. Precision of mandibular teeth was enhanced by amalgamating the CBCT scan with e-cast scan of the patient lower teeth. 3-Matic software (v. 10.0) was used in designing cutting guide(s) that define the amount of overgrowth to be resected. The top section of the guide was resting on the teeth hence ensuring stability and accuracy while positioning it. The guide design was exported as an .stl file and printed using in-house 3-dimensional printer in biocompatible resin. Conclusion Three-dimensional technologies of both softwares (CMF Pro Plan and 3-Matic) are accurate and reliable methods in the diagnosis, treatment planning, and designing of cutting guides that optimize surgical correction of hemimandibular hyperplasia at timely and cost-effect manner.

In patients with mild to moderate Parry-Romberg syndrome (PRS), plastic surgeons have mainly focused on the restoration of soft tissue deficiencies. While, bone deficits are easily overlooked. This study developed a new method combines the autologous mandibular outer cortex (MOC) grafting with fat grafting in mild to moderate patients with PRS, and apply computer-assisted techniques to improve the surgical outcomes and accuracy.Seven patients with mild to moderate PRS were prospectively enrolled in the study. Preoperative and 7 days and 6 months postoperative computed tomography (CT) and photographs were performed. Computer-aided design was done based on preoperative CT data. Surgical templates for MOC harvesting and grafting were designed and printed out. The topographic map of fat grafting was generated. The accuracy of MOC bone grafting was evaluated by the MOC thickness relative error, the MOC thickness accuracy at the preop most severe bone atrophy point (preop MSBAP), and the MOC volume accuracy. The percentage volume maintenance of the fat grafting surgery was assessed.All 7 patients had ideal clinical outcomes with significant improvement in facial symmetry and no major complications happened. The average MOC thickness relative error is 2.85 ± 0.50%. The average MOC thickness accuracy at the preop MSBAP is 3.36 ± 1.13%. The average MOC volume accuracy is 3.41 ± 1.37%. The average percentage volume maintenance of fat grafting is 62.79 ± 5.73%.The combination of MOC grafting with fat grafting can be an excellent choice in reconstruction of mild to moderate patients with PRS. Applying computer-assisted techniques offers a reliable and accurate outcome.

Reduced volume of the internal skeletal dimensions of the face is 1 of the main causes of obstructive sleep apnea, and attention to patients' airways is necessary when planning orthognathic treatment. This study aims to describe changes in upper airway volume following virtually planned orthognathic surgery. A retrospective pilot study was designed with 30 randomly selected patients (10 men and 20 women, aged 23.1±6.8 years, molar-relations: 15 neutral, 8 distal, and 7 mesial). Cone-beam computed tomography scans were performed before surgery and 1 week following surgery. The authors did total upper airway volume measurements and obtained 1-mm slices at vertical levels in the velo-, oro-, and hypopharynx and at the smallest visible crosssection. Measurements before and after surgery were compared using Student t test. After orthognathic surgery, the minimum cross-sectional area at the vertical level increased from 83 mm3±33 before surgery to 102mm3±36 after surgery (P=0.019). In patients with neutral and distal occlusions, the minimum cross-sectional slice volume increased in 87% but in only 57% with mesial occlusion. The present findings suggest that orthognathic surgery increases upper airway volume parameters, but a few patients have continued impairment of the airways following orthognathic surgery. Further studies are needed to confirm an individual surgical planning approach that potentially could bring the minimum cross sectional area out of the risk zone.

To prevent or treat for complications of reconstruction plate, such as metal plate fracture, plate exposure, and formation of skin fistula, the use of reconstruction plates on the mandibular lingual aspect has been introduced. However, this method increases the difficulty of surgery and lengthens the surgery time. In this study, the authors aimed to present a method to apply for reconstruction plates on the lingual side of the mandible to overcome the complications associated with the use of these plates. In the proposed method, the reconstruction plate was bent and fixed by a specially designed screws on a three-dimensional model created through a pre-operative virtual surgical simulation. Next, the model, prebent reconstruction plant, and screw were 3-dimensionally scanned and then superimposed precisely onto the three-dimensional model generated through the virtual surgical simulation. After extracting the three-dimensional path of the screws on the superimposed model, a surgical guide was prepared to drill screw holes in the buccal side of the mandible by transferring the extracted paths. The proposed surgical method using virtual surgical planning and surgical guides makes mandibular lingual application of the prebent reconstruction plates convenient, fast, and precise through drilling in the buccal side of the mandible.