OBJECTIVETo evaluate the predictive accuracy of the SurgiCase CMF software in surgical simulation and prediction for mandibular asymmetry with 3-dimensional simulation and measurement.

METHODSCBCT data of 27 patients with mandibular asymmetry were observed in CMF, and postoperative soft tissue physiognomy were predicted by simulating sagittal ramus osteotomy with or without genioplasty. The measurement parameters representing the symmetry of soft tissue were selected and the horizontal, coronal and sagittal planes were established. The results were analyzed by SPSS 19. 0. The overlap compared color grading charts were observed.

RESULTSAngles between cheilions and the horizonta plane (Ch-Ch-FH) in the simulation and postoperative soft tissues are (2. 35 ± 1. 81)° and (1. 44 ± 1. 13)°. The angles constructed among subnasale, upper lip and lower lip (Sn-UL-LL) are (4. 02 ± 3. 05)° and (2. 59 ± 1. 64)°, showing statistically different (P < 0. 01, P < 0. 05), which means that predictive accuracy of the lip canting and lip vertical deviation is relatively low. Distance between gonioi and sagittal plane (Go'-MS), distance between gonion and pogonion (Go'-Pog') and angle betweer subnasale to menton and the horizontal plane (Sn-Me'-MS) are not statistically different, which mean! high predictive accuracy of mandibular angle and chin. By observing the overlap compared color gradin-) charts, the predictive accuracy is not good in the cheek, especially in the deviate side.

CONCLUSIONSThe predictive accuracy of CMF system for patients with mandibular asymmetry is relatively high, but it is not good in the lip and cheek. The software improvement is still necessary.

Cephalometry ; methods ; Chin ; anatomy & histology ; Cone-Beam Computed Tomography ; methods ; Face ; Humans ; Lip ; anatomy & histology ; Mandible ; abnormalities ; surgery ; Osteotomy ; methods ; Software ; Surgery, Computer-Assisted ; methods

Objective To investigate the risks of self-rated health in the ≥55-year elderly in Beijing and the occurrence of stroke.Methods The subjects (n=2 101;aged ≥55) from Beijing longitudinal study of aging (BLSA) were collected by Xuanwu Hospital,Capital Medical University from January 1992 to December 2016.One hundred and twenty-one subjects with stroke at baseline and 92 with incomplete information were excluded,and finally,1 888 elderly patients without cerebrovascular disease at baseline were included in the analysis.Based on the actual situation,the self-rated health was to identify an item that matched their current state from good,general to poor.The deadline for the survey was December 31,2012.The competitive risk model was used to assess the health self-rated status and the risk of stroke.Non-stroke deaths,including cancer and car accidents were treated as competitive events.Results Of the 1 888 subjects enrolled,946 (50.1%) self-rated health were good,616 (32.6%) were general,and 326 (17.3%) were poor;438 (23.2%) had stroke,751 (37.8%) had non-stroke death,and 699 (37.0%) were right censored data.Using the competing risk model and adjusting the age,sex,living area,marital status,education level,smoking,alcohol consumption,physical exercise,hypertension,diabetes mellitus,coronary heart disease,and body mass index,the occurrence of stroke in patients with poor self-rated health was 1.44 times (95%CI 1.11-1.87,P<0.01) as good as those who were good.Conclusion In the self-rated health of the elderly ≥55 years old in Beijing,the people with poor self-rated health increased the occurrence of stroke after considering the competitive risks.

Objective:To establish a computer-aided design and 3D printing system for precise implantation of micro implant anchorage, and accurately calibrate the position and direction of micro implant implantation.Methods:A retrospective selection was conducted on 15 patients (30 in total) who underwent micro implant implantation surgery from the Department of Stomatology, the Affiliated Hospital of Jiangnan University from November 2019 to November 2021, including 6 males and 9 females, aged (17.1±6.3)years old. The preoperative patient was photographed with cone beam computed tomography (CBCT) and the collected DICOM data format was output. A 3D scan was performed on the patient′s preoperative analysis model to obtain the STL file of the model scan. The CBCT data and model data were fitted and matched using 3Shape Implant Studio software, and the thickness of the guide plate, the amount of undercut compensation, and the size of the key component collar were designed. The 3D printer was used for printing after resizing. Using the assist method to implant micro implants, CBCT was taken postoperatively to compare the preoperative design with the postoperative results.Results:After fitting the postoperative CBCT with the designed CBCT of the micro implant, it was found that the micro implant was consistent with the preoperative design, maintained a safe distance and parallel to the adjacent tooth root, and did not damage the maxillary sinus and other areas. No detachment of the micro implant anchorage was observed 1 or 3 months after surgery. The application of assisted micro implant anchorage 3D guide plate was reliable, with accurate implantation position and direction, and can be implanted in most parts of the oral cavity.Conclusions:The use of computer-aided design and 3D printing system to create an assistive micro implant anchorage 3D guide plate can accurately locate the position and direction of the micro implant, which is worthy of clinical promotion and application.