The comparison of 3D printing surgical guide and traditional occlusal splint in the treatment with facial asymmetry cases / 中华整形外科杂志

Objective@#To compare the surgical accuracy of the 3D printing surgical guide and traditional occlusal splint in the treatment of skeletal facial asymmetry cases.@*Methods@#12 facial asymmetric patients underwent joint orthognathic and orthodontics treatments were included in this research. In the 3D printing group (n=6) the pre-surgical CT scan for the skeleton and laser scan for the dentures were performed and 3D orthognathic procedures including Le FortⅠ and BSSRO combined with genioplasty were planned. The 3D printing surgical guides were manufactured and applied during surgeries. Another 6 cases were received same procedures by traditional occlusal splint techniques as the control group. Post-surgical CT reconstruction and 3D superimposition with pre-surgical planning was carried out for outcome comparison.@*Results@#The maximal error of maxillar was 0.65 mm and average error was less than 1 mm in 3D printing group, while the maxillary maximal error was 2.11 mm and average error was greater than 1 mm in traditional group which showed the statistical significance (P<0.05).@*Conclusions@#The usage of 3D printing surgical guide could improve the orthognathic surgical precision by controlling the jaw bone in a three-dimensional way.

Application of systematic simulation training program in flexible ureteroscopy training / 第二军医大学学报

Objective To evaluate the value of systematic simulation training program in the training of flexible ureteroscopy. Methods The training course was divided into three parts: shifting and positioning of flexible ureteroscope, stone-grasping with basket and lithotripsy by holmium laser. Thirty trainees in the flexible ureteroscopy training class in our hospital in March 2017 were prospectively selected and divided into 2 groups: standardized systematic training group and autonomous training group, with 15 trainees in each group. The trainees in the standardized systematic training group gradually completed the training contents of the three parts in strict accordance with the contents and forms of the training courses using in vitro training dry simulator, spending 60 min in each course, while the trainees in the autonomous training group completed the training by self-study using in vitro training dry simulator for 180 min. After completing the training, the trainees in the two groups were assessed by the in vitro training dry simulator and pig animal surgery, and the examination items included the shifting and positioning of the flexible ureteroscope in the animal surgery system or the dry simulator, stone-grasping with basket, and lithotripsy by holmium laser. The operating time and global rating scale (GRS) score for the operation by tutor were compared between the two groups. Results The operating time for the shifting and positioning of the flexible ureteroscope in the animal surgery system or the dry simulator, stone-grasping with basket, and lithotripsy by holmium laser in the standardized systematic training group were significantly shorter than those in the autonomous training group (all P<0.05). The GRS scores for the above operations in the standardized systematic training group were higher than those in the autonomous training group (all P<0.05). Conclusion The systematic simulation training program divides the flexible ureteroscopy training course into three separate parts, improves the learning efficiency and enthusiasm of the trainees, helps the trainees quickly mastering the operation skills of flexible ureteroscopy, and shortens the learning curve.

Prediction of Amount of Mandibular Set Back with 3 Plain Radiographs in Mandibular Sagittal Split Ramus Osteotomy

Development of New Orthognathic Model Surgery Technique Based on the Reference Points onto the Teeth and the Use of Occlusal Index

Accuracy of digital model surgery for orthognathic surgery: a preclinical evaluation

Orthognathic surgery using model repositioning instrument: a case report

The Accuracy of measurements during model surgery for orthognathic planning

The errors in orthognathic surgery can occur during the preoperative preparations including the model surgery, but till now there's been some lack of reserches about them. So we wanted to verify the accuracies in measurements used in model surgery. We compared the accuracy of measurements by vernier calipers, which has been the main measurement tool for conventional model surgery, and that by height gauge, which is recently claimed to be more accurate, with 3 dimensional coordinate analyzer. We could have following results and have a plan to use them for the invention of new model surgery techniques. 1. The measurement errors in Group 1, which mean the difference between "the measurements by 3-D analyzer" and "the measurements by height gauge", were small enough with the range of 0.1~0.2mm in all planes. 2. The mean error in Group 2, which is the differences between the measurements of 3-D analyzer and those of vernier calipers, was 1.1mm. 3. The measurement errors in Group 2 were variable according to the factors including the differences of individuality and expertness of each measurers. But in case of Group 1, they were small and not variable by the expertness. 4. The measurements were more accurate at the points in anterior teeth than in molar teeth in Group 1 and 2. 5. The errors after model surgery increased remarkably, compared with those before surgery in Group 2. And the situation was different in Group 1 in that errors decreased after surgery. Accoding to these results, it assumed that the measurements with height gauge during the model surgery for orthognathic surgery are accurate enough and can be maintained, regardless of complexity of models, individuality, or expertness of measurers.

Management of Maxillary or Mandibular Fractures with Model Surgery and Occlusal Splint

Maxillary and mandibular fractures account for a large proportion of facial bone fractures. The primary objective in reduction of marillary or mandibular fractures is to return the structures to normal position of function and cosmetic contour, i.e. restoration of normal occlusal relations through proper positioning of the teeth and bony structures. Interdental wiring, intermaxillary fixation, rigid internal fixation or external pin fixation are common methods in the management of jaw fractures, varying with the age of the patient, location or extent of fracture. Malocclusion is not an uncommon complication after management of jaw pacture. We managed 16 patients (13 males, 3 females) of mandibular or maxillary fractures with model surgery and occlusal splint from July 1998 to August 1999. The average age of patients was 27.4 years and the average follow-up period was 6 months. We achieved good occlusal relationship without malunion, nonunion, or loss of teeth. Acrylic occlusal splints are rigid, strong, easily adjusted and repaired, translucent, lightweight and tolerated well by the oral mucosa. It is useful in the maintenance of intermaxillary fixation and in maintaining continuity of the maxillary or mandibular dental arch, as well as providing precise dental alignment during healing. Splints are helpful in managing fractures of the symphysis, parasymphyseal region, body and alveolar ridges of the mandible, sagittal fractures of the hard palate, and severely comminuted mandible fractures.