The aim of this study was to compare and evaluate the anchorage effectiveness of using either micro-implants or extraoral headgear with the McLaughlin-Bennett-Trevisi (MBT) system. Thirty young Chinese adults (14 males and 16 females) aged 18-22 years with anterior bimaxillary protrusion were divided randomly into two equal groups, treated with the MBT system anchored by either micro-implants or headgear. Nine measurements obtained before and after treatment from lateral cephalometric radiographs were assessed for the two groups, using the Mann-Whitney U test with alpha = 0.05 for statistical significance. The maxillary incisors in the micro-implant group were significantly more retracted and intruded, while the lower incisors were more lingually inclined, than in the headgear group. The occlusal and mandibular planes were rotated more counterclockwise in the micro-implant group than in the headgear group (P < 0.05). Compared with headgear anchorage, micro-implant anchorage may counteract clockwise rotation of the occlusal and mandibular planes and result in different final positions for the maxillary and mandibular incisors.

Objective: To propose a three-dimensional (3D) method for evaluating temporomandibular joint (TMJ) changes during Twin-block treatment. Methods: Seventeen patients with Class II division 1 malocclusion treated using Twinblock and nine untreated patients with a similar malocclusion were included in this research. We collected their cone beam computed tomography (CBCT) data from before and 8 months after treatment. Segmentations were constructed using ITK-SNAP. Condylar volume and superficial area were measured using 3D Slicer. The 3D landmarks were identified on CBCT images by using Dolphin software to assess the condylar positional relationship. 3D models of the mandible and glenoid fossa of the patients were constructed and registered via voxel-based superimposition using 3D Slicer. Thereafter, skeletal changes could be visualized using 3DMeshMetric in any direction of the superimposition on a color-coded map. All the superimpositions were measured using the same scale on the distance color-coded map, in which red color represents overgrowth and blue color represents resorption. Results: Significant differences were observed in condylar volume, superficial area, and condylar position in both groups after 8 months. Compared with the control group (CG), the Twin-block group exhibited more obvious condyle-fossa modifications and joint positional changes. Moreover, on the color-coded map, more obvious condyle-fossa modifications could be observed in the posterior and superior directions in the Twin-block group than in the CG. Conclusions: We successfully established a 3D method for measuring and evaluating TMJ changes caused by Twin-block treatment. The treatment produced a larger condylar size and caused condylar positional changes.

A 23-year-old woman presented with a class III malocclusion, with crowded and malformed teeth and excessive gingival display. During orthodontic treatment, a Tomas orthodontic miniscrew was placed between the root apices of the maxillary central incisors. This was carried out by an orthodontic specialist who had treated more than 700 patients (with more than 2000 mini-implants) over the past 9 years. After 2 weeks of treatment, the right maxillary central incisor discoloured and did not respond to electrical pulp tests (EPT) but was sensitive to endo-ice. The miniscrew was removed under local anaesthesia. Teeth 11 and 21 were fixed with ligation wire, and glass-ionomer cement (GIC) was added to the occlusal surfaces of the first and second maxillary molars to heighten the occlusion and disclude the maxillary anterior teeth. After 4 months, the colour and pulp reactions to EPT and endo-ice of tooth 11 returned to normal. Because the use of a miniscrew had appeared to damage the pulp, subsequent a conservative orthodontic treatment using, traditional 'J' hooks was used and achieved satisfactory results. After 23 months of orthodontic treatment, the treatment was complete and a 15-month follow-up showed a successful outcome.

Introduction: Due to break space and time limits, an entirely new online curriculum of orthodontic education with online evaluation system has been structured and developed in the dental school, based on virtual reality simulation.Curriculum: At Nanjing Medical University, a new online orthodontic curriculum with programmatic assessment process was constructed and implemented based on competency-based education (CBE). It was consisted of the online orthodontic theoretical lectures based on the National Open Online Course "Orthodontics," the online journal club via the online "flipped classroom," and the online orthodontic pre-clinical training via the virtual learning network platform. In order to evaluate this curriculum, 94 Year 4 dental students took part to complete the online orthodontic curriculum. The mean total score of all the students was 91.99, and the element scores of the online theoretical lectures, journal club, virtual pre-clinical training, and online final examination were respectively 96.83, 79.49, 96.00, and 87.02, which showed a good performance.According to the student feedback toward this curriculum via the online questionnaire, nearly 98% of the students showed agreement or strong agreement that the online orthodontic curriculum has enhanced their orthodontic theoretical understanding and orthodontic practical ability. Conclusion: As a student-centered CBE, this online orthodontic curriculum with online evaluation system could provide both orthodontic theory and practice teaching for all the dental students at all times and places based on the online virtual mode, which enriched learners' critical thinking, problem solving, and assessment skills.