Exploration of Novel Genetic Evidence and Clinical Significance Into Hemifacial Microsomia Pathogenesis.

The authors browsed through past genetic findings in hemifacial microsomia along with our previously identified mutations in ITGB4 and PDE4DIP from whole genome sequencing of hemifacial microsomia patients. Wondering whether these genes influence mandibular bone modeling by regulation on osteogenesis, the authors approached mechanisms of hemifacial microsomia through this investigation into gene knockdown effects in vitro. MC3T3E1 cells were divided into 5 groups: the negative control group without osteogenesis induction or siRNA, the positive control group with only osteogenesis induction, and 3 gene silenced groups with both osteogenesis induction and siRNA. Validation of transfection was through fluorescence microscopy and quantitative real-time Polymerase chain reaction on knockdown efficiency. Changes in expression levels of the 3 genes during osteogenesis and impact of Itgb4 and Pde4dip knockdown on osteogenesis were examined by quantitative real-time Polymerase chain reaction, alkaline phosphatase, and alizarin red staining. Elevation of osteogenic genes Alpl, Col1a1, Bglap, Spp1, and Runx2 verified successful osteogenesis. Both genes were upregulated under osteogenic induction, while they had different trends over time. Intracellular fluorophores under microscope validated successful transfection and si-m-Itgb4_003, si-m-Pde4dip_002 had satisfactory knockdown effects. During osteogenesis, Pde4dip knockdown enhanced Spp1 expression (1.95±0.13 folds, P =0.045). The authors speculated that these genes may have different involvements in osteogenesis. Stimulated expression of Spp1 by Pde4dip knockdown may suggest that Pde4dip inhibits osteogenesis.

The Feasibility of Electromagnetic Navigation Technique to Achieve Preoperative Plan in Mandibular Angle Osteotomy.

BACKGROUND: In contrast to the most commonly used optical navigation system, electromagnetic navigation has huge potential in operations with a narrow field. The purpose of this experiment was to test and confirm whether the electromagnetic navigation method the authors developed for mandibular angle osteotomy (MAO) met clinical requirements. METHODS: Using a dental splint that could be repeatedly mounted on teeth, registration between surgical plan and actual field was performed automatically. RESULTS: Navigation of MAO was first performed on 10 mandibular models. The position precision measured using a coordinate measuring machine was 1.30±0.61 mm. Then, a navigation experiment was performed on 4 patients. Accuracy in actual operation measured by the NDI pointing sensor was 1.89±0.76 mm. Our noninvasive automatic registration process reduced the surgical exposure time and eliminated the bias of the manual selection of registration points. CONCLUSIONS: This preliminary study confirmed the feasibility of the electromagnetic navigation technique in terms of both applicability and accuracy in MAO surgery.

Fully Automatic Robot-Assisted Surgery for Mandibular Angle Split Osteotomy.

With the development of computer-assisted surgery, preoperational design is detailed in software. However, it is still a challenge for surgeons to realize the surgical plan in the craniofacial surgery. Robot-assisted surgery has advantages of high accuracy and stability. It is suitable for the high-stress procedures like drilling, milling, and cutting. This study aims to verify the feasibility for automatic drilling without soft tissues in model test based on an industrial robot platform.This study chose the data from digital laboratory in Shanghai 9th People's Hospital. The mandibular was reconstructed in software and surgical plan was also designed. Then, the coordinate data was input to the robot's software and matrix conversion was calculated by 4 marked points. The trajectory generation was calculated by inverse kinematics for target coordinates and robot coordinates. The model was fixed and calibrated for automatic drilling. At last, the accuracy was calculated by optic scanning instrument.The installment and preparation cost 10 minutes, the drilling procedure cost 12 minutes. The outside position error was (1.71 ±â€Š0.16) mm, the inside position error was (1.37 ±â€Š0.28) mm, the orientation error was (3.04 ±â€Š1.02)°. Additionally, a total of 5 beagles were tested, with an accuracy error of (2.78 ±â€Š1.52) mm. No postoperative complications occurred.This is the first study reported for robot-assisted automatic surgery in craniofacial surgery. The result shows it is possible to realize the automatic drilling procedure under the condition of no interference like soft tissues. With the development of artificial intelligence and machine vision, robot-assisted surgery may help surgeons to fulfill more automatic procedures for craniofacial surgery.

Automated Lesion Segmentation and Quantitative Analysis of Nevus in Whole-Face Images.

BACKGROUND: Nevus is very common; however, melanoma is slightly related to the deterioration of nevus because of its vulnerability to solarization, friction, aging, heredity, and other factors. Early diagnosis is essential for melanoma treatment, since patients have a high survival rate with early detection and treatment. Computer-aided diagnosis has been applied in the differential diagnosis of melanoma and benign nevi and achieved high accuracy, but it does not suit the screening of nevi because most studies are based on dermoscopy with a narrow field of vision and performed by professional doctors. Therefore, this study aimed to present the accuracy and effectiveness of our algorithm. METHODS: Based on whole-face images of patients, the authors used logistic regression and the Newton method to detect the nevus region. Then, Python and OpenCV were employed to detect the lesion edge and compute the area of the regions. A multicenter clinical trial with a sample size of 600 was then conducted to evaluate the effectiveness of the algorithm. RESULTS: The algorithm detected 2672 nevi from 600 patients, in which there were 195 patients of missed diagnosis and 310 patients of misdiagnosis. The Kappa value between 2 groups was 0.860 (>0.8). Paired t-test showed no significant difference between 2 groups' area results (P = 0.265, P > 0.05). CONCLUSION: Within the limitations of this study, the authors demonstrated a high agreement between algorithm's detection and doctor's diagnosis. Our new algorithm has great effectiveness in nevus detection, edge segmentation, and area measurement.

Computer-assisted surgery in therapeutic strategy distraction osteogenesis of hemifacial microsomia: Accuracy and predictability.

BACKGROUND: Distraction osteogenesis can be used to treat hemifacial microsomia in patients of any age group. Application of three-dimensional (3D) technology in the surgical planning of distraction osteogenesis allows the placement of an intraoral distractor to define the cutting line and help predict the outcome of surgery. AIM: This study compared the results of distraction osteogenesis performed, using computer-assisted surgery, on OMENS-plus-classified M2A, M2B, and M3 type patients. Comparisons were in terms of either accuracy or predictability. METHODS: 40 patients were selected to participate in the 8-month study. Preoperative image data from 3D-CT scans of the 40 patients were translated into DICOM format 3D cephalometrics, run using the computer software MIMICS version 18, and based on eight reference anatomical landmark points, five lines of measurement, and the midline of the mandibular plane. The distraction vector for the affected side of mandible was selected and the elongation process simulated repeatedly until satisfactory results were obtained. The surgical guide was created using CAD/CAM-RP technology. The distraction osteogenesis procedure was then performed using the surgical guides. Follow-up for all patients continued until 8 months postoperatively. Accuracy with and without computer-assisted surgery was assessed linearly and volumetrically. Simple mean comparisons and paired t-tests were conducted using IBM SPSS V21. RESULTS: In those patients who received computer-assisted surgery, distraction in the M2A type mandible showed accuracy of around 97.77% ± 7.92% (p > 0.05) for height and 97.91% ± 10.23% (p > 0.05) for length of the mandible. Meanwhile, the M2B type mandible presented accuracy of around 93.85% ± 8.07% (p > 0.05) for height and 95.85% ± 10.16% (p > 0.05) for length. For the M3 type mandible accuracy was around 98.42% ± 6.58% (p > 0.05) for height and 97.14% ± 11.45% (p > 0.05) for length. These measurements showed no significant differences between preoperative design and real outcome. CONCLUSIONS: Individualized guides improve the accuracy of distraction osteogenesis. They help the surgeon to identify the mandibular defect and ensure the desired outcome after the operation.