Advances in Robot-Assisted Surgery for Facial Bone Contouring Surgery.

Since our team reported the application of robot-assisted surgery in facial contouring surgery in 2020, further clinical trials with large samples have been conducted. This paper will report the interim results of a single-center, large-sample randomized controlled trial of the first robot developed by our team for facial contouring surgery. Meanwhile, this research field will be systematically reviewed and prospected.

Current Practices for Esthetic Facial Bone Contouring Surgery in Asians.

In this article, authors mainly introduce new digital technology in facial bone contouring surgery. In our experience, these new technologies are crucial in ensuring the satisfaction of surgical accuracy. Our previous studies have shown surgeons can use precise pre-operative design to reduce operative time, reduce bleeding during surgery. Additionally, augmented reality can enhance the perspective perception of surgeons combining virtuality and reality. What's more, robot-assisted surgical technology also has a strong application prospect in facial contouring surgery. In the future, the combination of soft tissue contouring surgery will make the facial bone contouring surgery safer and more effective.

Minimally Invasive 980 nm Laser-Assisted Lipolysis and Skin Tightening on Lower Eyelids of Asian Patients.

OBJECTIVE: The present study aimed to evaluate the effectiveness of minimally invasive 980 nm laser-assisted lipolysis and skin tightening in lower eyelid blepharoplasty of Asian patients. METHODS: Patients with mild and moderate degree of eyebags underwent 980 nm laser-assisted lipolysis via lower eyelid stab incision between December 2017 and December 2019. Evaluation criteria was reviewed by photographs taken preoperatively and 6 months postoperatively in accordance with guidelines of Global Aesthetic Improvement Scale, the patient's perspective from the questionnaire with the perception of reduction in eyebags size, the average perception of improvement in skin tightening, and the patient overall satisfaction, all with a score of 1 to 5 (5 being the most noticeable and very satisfied) and complications such as dyspigmentation, hematoma, prolonged edema, skin bump and thermal burn were documented as well. RESULTS: A total of 178 cases with 137 women and 41 men (age range from 23 to 50 years) were included. Total energy of 1200 J to 2000 J was delivered to both eyebags at 6 to 10 W. They were followed up for at least 6 months. A total of 166 patients (93.26%) revealed an improvement in Global Aesthetic Improvement Scale, with the 12 patients (6.74%) complaint no change 6 month postoperatively. Perception of improvement in eye bag protrusion scored 4.39 ± 0.59, improvement in skin tightening scored 4.42 ± 0.58 and the overall patient's satisfaction scored 4.59 ± 0.53. The patients' average recovered swelling from 4.35 ± 2.3 days. There were 5 patients (2.8%) with dyspigmentation, 3 patients (1.69%) with prolonged edema and 2 patients (1.12%) with skin bump and none of the patients had thermal burn. All of them resolve after 6 months of follow up. CONCLUSION: Patients with mild to moderate degree of eyebags who resist surgery are good candidates for laser-assisted lower eyelid blepharoplasty.

Preliminary reports of augmented-reality assisted craniofacial bone fracture reduction.

BACKGROUND: Zygomaticomaxillary complex fractures involve four fracture ends. It is difficult to fully expose the operative area through a main coronal incision, an intraoral incision, and an eyelid incision. To address the partial visual field loss in craniofacial fracture reduction, we attempted to use an augmented reality (AR) navigation system. METHODS: Patients with zygomaticomaxillary complex fractures underwent three-dimensional (3D) computed tomography (CT) modeling before surgery, and preoperative plans were designed. The control team used traditional optical navigation to perform the surgery. The experimental team used an AR navigation system. From May 2019 to December 2019, 10 patients with zygomaticomaxillary complex fractures were included in this study. Data were collected after surgery and analyzed. RESULTS: There was a significant difference between the two groups in the fracture point error (1.35 vs. 1.61, P = 0.02) and fracture reduction time (15.40 vs. 20.40, P = 0.03). However, there was no difference in the operative duration (6.60 vs. 6.65, P = 0.92), blood loss volume (620.00 vs. 580.00, P = 0.83), or incidence of complications. CONCLUSIONS: The AR navigation system used by the research team has good auxiliary effects for reducing zygomaticomaxillary complex fractures. The new surgical method has better accuracy and a shorter reduction time than the traditional surgical method.

The application of augmented reality in craniofacial bone fracture reduction: study protocol for a randomized controlled trial.

BACKGROUND: Augmented reality (AR) is a new technology that increases users' perception of the real world. The purpose of this study is to evaluate the efficacy and safety of augmented reality navigation system in treatment with craniofacial fracture reduction. METHODS: This will be a single-center prospective randomized controlled trial. Twenty-two patients will be assigned to two groups of 11, and those with zygomaticomaxillary complex fractures will undergo preoperative three-dimensional CT modeling and have operational plans designed. The control team will use traditional optical navigation to perform the surgery, and the experimental team will use an AR navigation system. The primary outcome measures will be the accuracy of the key points of surgical area between the preoperational surgical plan and post-operation. The secondary outcome measures will be the blood loss, operation time, bone reduction time, hospital time, and complication rate. The findings obtained through this study are expected to evaluate efficacy and safety of the augmented reality navigation system in the treatment of zygomaticomaxillary complex fractures. DISCUSSION: This controlled trial of augmented reality navigation system in treatment with zygomaticomaxillary complex fracture reduction will clarify the efficacy and safety of this technology by measuring the accuracy of the key points of surgical area and blood loss, operation and bone reduction times, hospital stay duration, and complication rates. This is a single-center study, and the results are expected to promote the application of augmented reality in craniofacial fracture reduction to improve surgery accuracy and efficacy. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900022626 . Registered on April 19, 2019.

Correlations Between Mandible Condylar Structures and External Ear Deformities in Hemifacial Microsomia With Three-Dimensional Analysis.

ABSTRACT: This study aimed to explore correlations between mandible and ear deformities and quantitative volumetric relations between condylar structures and external ear in hemifacial microsomia. The authors reconstructed three-dimensional craniofacial models from 212 patients with unilateral hemifacial microsomia (the unaffected side as the controls). Patients were evaluated by Pruzansky-Kaban and Marx classification, and divided into 3 age groups (0-6, 7-12, and >12 years of age). The mandible condylar structures, including condyle and the condylar skeletal unit, were selected (except the classification of the mandibular or ear deformities (M3)). Along with the external ear (except the classification of the mandibular or ear deformities (E4)), their volumes were measured and analyzed. Spearman correlation coefficient analysis was applied. There was a positive correlation between the mandible and ear deformities (r = 0.301, P   <  0.001). Either between the condyle and external ear ( P  = 0.071-0.493) or between the condylar unit and external ear ( P  = 0.080 - 0.488), there were no volumetric relations on the affected side, whereas on the unaffected side were (r = 0.492-0.929 for condyle, r = 0.443-0.929 for the condylar unit, P  < 0.05). In most cases, the condylar structures of the classification of the mandibular or ear deformities (M2b) were significantly smaller than the classification of the mandibular or ear deformities (M2a). Results suggested deformities of mandibular condylar structures and ear did not correlate, although deformities of mandible and ear did. The condylar deformity might develop independently from microtia and be more severe within relatively more abnormal temporomandibular joints.

LY3023414 inhibits both osteogenesis and osteoclastogenesis through the PI3K/Akt/GSK3 signalling pathway.

AIMS: LY3023414 is a novel oral phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) dual inhibitor designed for advanced cancers, for which a phase II clinical study was completed in March 2020; however, little is known about its effect on bone modelling/remodelling. In this study, we aimed to explore the function of LY3023414 in bone modelling/remodelling. METHODS: The function of LY3023414 was explored in the context of osteogenesis (bone formation by osteoblasts) and osteoclastogenesis (osteoclast formation and bone resorption). Murine preosteoblast MC3T3-E1 cell line and murine bone marrow-derived macrophage cells (BMMs) were subjected to different treatments. An MTS cell proliferation assay was used to examine the cytotoxicity. Thereafter, different induction conditions were applied, such as MCSF and RANKL for osteoclastogenesis and osteogenic media for osteogenesis. Specific staining, a bone resorption assay, and quantitative real-time polymerase chain reaction (qRT-PCR) were subsequently used to evaluate the effect of LY3023414. Moreover, small interfering RNA (siRNA) was applied to knockdown Akt1 or Akt2 for further validation. Lastly, western blot was used to examine the exact mechanism of action. RESULTS: LY3023414 attenuated PI3K/protein kinase B (Akt)/GSK3-dependent activation of ß-catenin and nuclear factor-activated T cell 1 (NFATc1) during osteogenesis and osteoclastogenesis, respectively. LY3023414 mainly inhibited osteoclast formation instead of mature osteoclast function. Moreover, it suppressed osteogenesis both in the early stage of differentiation and late stage of calcification. Similarly, gene knockdown of Akt isoforms by siRNA downregulated osteogenic and osteoclastogenic processes, indicating that Akt1 and Akt2 acted synergistically. CONCLUSION: LY3023414 can suppress osteogenesis and osteoclastogenesis through inhibition of the PI3K/Akt/GSK3 signalling pathway, which highlights the potential benefits and side effects of LY3023414 for future clinical applications. Cite this article: Bone Joint Res 2021;10(4):237-249.

Experience of Comprehensive Three Dimensional Epicanthoplasty With Upper Blepharoplasty in Asian Patients.

PURPOSE: To introduce the experience of comprehensive 3-dimensional epicanthoplsty with upper blepharoplasty in Asian patients. METHODS: The patients who underwent comprehensive 3-dimensional epicanthoplsty with upper blepharoplasty at the Shanghai Ninth People's hospital from January 2018 to January 2019 were included in our study. The interepicanthal distance was evaluated preoperatively and 6 months after the surgery, scar visibility and patient's satisfaction were documented 6 months after the surgery. RESULTS: A total of 72 patients (144 eyelids) were included in this study with ages ranging from 18 to 37 years (mean, 23.83 ± 4.64 years) and follow-up duration ranging from 6 to 12 months (mean, 7.82 ± 1.92 months). All patients were female and achieved esthetically favorable results without serious complications. No patients required revision surgery showing high patient satisfaction (score, 4.4). The preoperative mean interepicanthal distance was 33.13 ± 2.25 mm and decreased to 29.28 ± 2.26 mm postoperatively showing statistical significance (P < 0.001). Twenty-nine (40.3%) patients had no visible scarring, and 42 (58.3%) patients had minimal scarring, which was accepted by the patients. CONCLUSIONS: The comprehensive 3-dimensional epicanthoplasty with upper blepharoplasty is a surgical technique that is easy to perform, reliable, and effective in treatment of all types of epicanthal folds except type 4 with increase intercanthal distance, less visible scar, and high patient satisfaction in Asian patients.

A Preliminary Study on Animal Experiments of Robot-Assisted Craniotomy.

BACKGROUND: Traditional craniotomy relies on the surgeon's experience and can be complicated owing to excessive skull bone removal, undesirable brain tissue penetration, or severe bleeding. For craniotomy, we developed a robot system based on intraoperative cone-beam computed tomography image guidance and human-robot cooperative interaction, aiming to improve the safety and accuracy of surgery and reduce the labor-intensiveness of the procedure. METHODS: Intraoperative cone-beam computed tomography image guidance was adopt to improve the accuracy in our experiment. Craniotomy was performed using an interactive method based on human-robot collaboration, which could achieve a natural interactive method in accordance with surgeons' operating habits. The frequency-based method of contact distinction and the method of torque estimation were used to improve the safety of the designed robot. RESULTS: An animal experiment was conducted to verify the effectiveness of the robot system. During the drilling process, the position error was 0.92 ± 0.17 mm (upper surface) and 0.97 ± 0.11 mm (lower surface), and the angle error was 3.37 ± 1.43°. During the milling process, the position error was 1.06 ± 0.13 mm (upper surface) and 1.09 ± 0.09 mm (lower surface). The results showed that the system had sufficient precision and could better complete craniotomy with human-robot collaboration. In addition, with the feedback of multisensor information, the robot system could achieve a sufficient level of safety. CONCLUSIONS: The robot system can achieve accurate positioning and safe user-friendly human-robot interaction, which solves problems encountered in the drilling and milling of craniotomy, meets clinical needs, and provides a new method for robot-assisted craniotomy.

Model Experimental Study of Man-Machine Interactive Robot-Assisted Craniotomy.

ABSTRACT: To evaluate the feasibility, safety, and accuracy of the new man-machine interactive robotic system in model experiment. The implantation of the 8 to 10 bone screws over the skull model obtained from real patient's digital imaging and communications in medicine (DICOM), three-dimensional spiral computed tomography (CT) scans were taken. The end of the robotic arm was replaced with standard parts (including marker ball) for cone beam computed tomography (CBCT) scanning. The marker ball and marker pin were segmented and marked and exported via txt format. The position of the robotic end and model was obtained through the conversion of spacious position of standard parts and the executive end was replaced eventually. The water balloon was placed inside the skull model to imitate the dura mater and the destruction was documented for the system's safety. The system accuracy was evaluated by the error between the actual drilling position and the virtual plan and selection of 14 points of the skull window of milling pathway, monitored intraoperatively via Micron Tracker system and the overall skull window overlapped percentage via Mimics. Five model experiments were successfully performed with the average registration time of 3 minutes without destruction of balloon. The error of the outer table was 0.85 ±â€Š0.45 mm, the inner table was 0.78 ±â€Š0.49 mm, the line segment error of milling cutter was 0.93 ±â€Š0.50 mm and the overall skull window overlapped percentage was 97.37% ±â€Š0.78%. The system shows safety, accuracy, and reliability which can be an optional assistant method for craniotomy in the future.

Hyperbaric CO2 Cryotherapy for Managing Swelling After Mandibular Angle Ostectomy.

ABSTRACT: Postoperative facial swelling after mandibular angle ostectomy is a concern for patients as it affects their quality of life. This study aimed to evaluate the effect of hyperbaric CO2 cryotherapy in relieving postoperative swelling. Thirty-seven patients (mean age: 22.95 ±â€Š3.49 years) who underwent bilateral mandibular angle ostectomy from April to October 2019, were included in this study. A split-mouth design was adopted and through a random sequence, either side of the face was designated as the experimental side. Both received routine nursing care, while the experimental side underwent an additional hyperbaric CO2 cryotherapy treatment. The facial structure was recorded by a 3-dimensional laser scanner pre- and postoperatively. Geomagic Studio was used for alignment, visualization, and quantification of the swelling. The largest deviation value on each side was adopted to assess the overall swelling. Parameters were compared using the paired t-test, and P<0.05 was considered statistically significant. No necrosis of the skin and adjacent structures or other complications occurred in these patients. After the first day of cryotherapy, the deviation in the experimental and the control groups was (8.40 ±â€Š1.95) mm and (10.42 ±â€Š2.03) mm, respectively. The next day, after cryotherapy, the value further reduced to (5.42 ±â€Š1.36) mm and (8.24 ±â€Š2.22) mm for the experimental and control groups, respectively. And the effect remained till the seventh day. No difference was observed in terms of volume of drainage. Hyperbaric CO2 cryotherapy is safe and effective in relieving postoperative swelling and seems to be more effective than the traditional cold-pack treatment after mandibular angle ostectomy.

Evaluation of effectiveness of three-dimensional printed ear splint therapy following ear elevation surgery in microtia patients: A randomized controlled trial.

AIM: This study aimed to compare the effectiveness of a 3D-printed ear splint with that of a conventional thermoplastic ear splint after microtia reconstruction. METHODS: Patients who underwent ear elevation surgery with postauricular fascia coverage between October 2017 and October 2018 were included. They were randomly divided into the experimental group (3D-printed ear splint) and the control group (thermoplastic ear splint) and underwent routine postoperative rehabilitation and antiscar therapy. Splint therapy was initiated 4 weeks postoperatively and continued until 24 weeks postoperatively. The evaluated indices were the Vancouver scar scale score (VSS score), cranioauricular distance, patient compliance, complications (dermatitis, skin ulcers, skin necrosis), and patient satisfaction. A two-group t-test was carried out to compare all variables except patient satisfaction, which was compared using the Mann-Whitney U-test; p < 0.05 was considered significant. RESULTS: Twenty patients were included in each group. At 4 weeks postoperatively, the VSS score (p = 0.748) and cranioauricular distance (p = 0.647) showed no significant differences between the groups. At 24 weeks postoperatively, the mean VSS scores were 4.85 ± 1.46 and 6.25 ± 1.74 (p = 0.009), the mean cranioauricular distances were 15.80 ± 1.82 mm and 13.95 ± 1.93 mm (p = 0.004), and the patient satisfaction scores were 4.5 ± 0.51 and 3.7 ± 0.47 (p < 0.001) in the experimental group and the control group, respectively, all showing significant differences. Two patients in each group exhibited skin irritation or skin ulcers, which resolved after 6 months of follow-up. CONCLUSION: The application of 3D-printed ear splints provides better inhibition of scar contracture, better maintenance of ear projection and higher patient satisfaction than conventional ear splints following ear elevation surgery in microtia patients. Therefore, 3D-printed ear splints should be preferred over conventional ear splints whenever possible.

A new method for cranial vault reconstruction: Augmented reality in synostotic plagiocephaly surgery.

PURPOSE: Augmented reality (AR) is considered to be a valuable tool in craniofacial surgery for preoperative design, intraoperative navigation, and postoperative assessment. Corrective surgery is necessary synostotic plagiocephaly for functional and aesthetic outcomes. Open calvarial reconstruction is a difficult classic surgical procedure with a high accuracy requirement. The purpose of this study was to introduce an AR system application in synostotic plagiocephaly surgery. MATERIALS AND METHODS: Seven plagiocephaly patients (ages 6 months-24 months, average 16.7 months) were enrolled. Preoperative design was accomplished based on three-dimensional computed tomography (CT) data for patients with synostotic plagiocephaly. We completed the registration with the predefined markers through an image registration process preoperatively. Then, we overlaid the registration results into the surgical field to assist surgeons intraoperatively. CT scans were performed postoperatively. Intracranial volume was measured to judge the surgical outcomes. We performed a quantitative craniometric analysis between the planning of the reconstruction and post-operative results, and the main evaluation indicator was the intracranial volume asymmetry. RESULTS: We successfully applied the AR system in patients undergoing synostotic plagiocephaly, providing real-time navigational images of position and orientation information during open calvarial reconstruction surgery in 7 plagiocephaly patients within a span of 5 years. Good appearances were observed after the surgery. Cranial volume asymmetry was decreased from 27.87% to 16.57%, achieving precise intra-operative goals. No significant differences were found between planning and post-operative results. CONCLUSIONS: The AR system can be applied to plagiocephaly procedures guiding to obtain reliable and accurate results via a precise osteotomy.

Whole-exome sequencing for monozygotic twins discordant for hemifacial microsomia.

Hemifacial microsomia (HFM) is the second most common congenital craniofacial malformation. Although many sporadic and familial cases have been studied to explore the etiology and pathogenesis of HFM, no common understanding has been reached. We aimed to further probe into the etiology of HFM through studying monozygotic twins. Here, we report two cases of pairs of monozygotic twins discordant for HFM, and performed whole-exome sequencing (WES) and bioinformatics analysis to help determine the underlying molecular mechanisms. We identified 93 and 83, and 101 and 104 genes containing rare germline mutations in the twins of the two pairs, respectively. No positive gene candidates were found among the samples, and none of the analyses results revealed a clear intersection with previously reported gene candidates. The pathogenesis of HFM twin pairs does not appear to be related to single nucleotide variants or small insertions/deletions. Thus, HFM may be caused by structure variations, epigenetic alterations, and/or instability of short repeat sequences, which requires further investigation in a larger cohort with sequencing technology for verification.

A Novel Rhinoplasty Sculpture Technique Using Ancient Chinese Architectural Technology.

Rhinoplasty is one of the most delicate procedures in plastic and reconstructive surgery. Precision in every millimeter is vital in ensuring a better quality of surgical outcome. Many methods have been developed to fulfill this requirement. One such method is an implant, whether autogenous or artificial. Artificial implants involve several surgical complications, such as recipient rejection of implant material, infections, and rigid feel of the nasal tip. Hence, autogenous implants were eventually more widely applied, with material being obtained from the septum, concha, or rib cartilages. Therefore, the authors developed a new technique of rhinoplasty, using the osteochondral rib as an autogenous implant based on the ancient Chinese architectural technology called the DouGong method. The authors hereby present the results of 288 patients treated in our faculty wherein the data from the patients and the preoperative and postoperative 3-dimensional computed tomography scans were processed using Mimics software. The uniqueness of these implants is that the joint between the nasal dorsum and the columella strut is fixated without any screw, stitches, or K-wire. This procedure proved to be very useful as this technique not only minimized the application of fixation techniques, but also helped achieve a better nasofrontal angle, nasolabial angle, and columella length. After monitoring follow-ups of our patients, the authors hereby propose the use of this DouGong-based novel technique to improve the overall quality and outcome of corrective rhinoplasty.