Orthodontics

This description observational research is comparative in design, that is comparing existing standard clinical dental images, not obtained in this study, to test (i.e., ddMRI) images. The standard clinical dental images consist of radiographs, such as bitewings, periapical, panoramic, cone-beam CT, and medical CT, as well medical MRIs of the temporomandibular joints (TMJ).The conceptualization of research questions, study designing, and interpretation of imaging data has and will involve content expertise in all ddMRI research.

The goal of this clinical trial is to evaluate the effectiveness of a novel lip bumper with an integrated distal shoe in preventing second molar impaction in children aged 8-10 years with anterior open bite during the mixed dentition stage. The main questions it aims to answer are: * Does the integrated distal shoe significantly reduce the risk of second molar impaction compared to conventional lip bumpers? * Does the appliance improve anterior open bite correction and influence lower incisor inclination? Researchers will compare Group I (lip bumper with distal shoe) to Group II (conventional lip bumper) to see if the modified appliance prevents mesial drift of first molars and improves eruption outcomes of second molars. Participants will: * Undergo initial records including panoramic and cephalometric radiographs, study models, and intraoral photos * Be fitted with one of the two appliances and followed up every 6 weeks over a 12-month period * Receive radiographic and clinical evaluation of second molar eruption * Complete assessments related to overbite changes, incisor inclination, comfort, and compliance This trial seeks to inform early orthodontic protocols and may offer a dual-function solution for both molar guidance and open bite correction.

Study on the changes in oral microbiota during orthodontic treatment in patients aged 8-18 years. Orthodontic patients treated at Stomatology Hospital of Xi'an Jiaotong University from March 2025 to March 2027 will be recruited. Prior to orthodontic treatment, routine preoperative examinations will be conducted, informed consent forms will be signed, baseline oral conditions will be recorded, and oral and psychological-related questionnaires will be completed. Patients will be informed of the need for regular oral hygiene check-ups, caries risk assessments will be performed, and plaque, saliva, and intraoral photographs will be collected. During orthodontic treatment, plaque samples will be collected every 3 months, and saliva samples will be collected every 6 months until the treatment is completed to evaluate the changes in oral microbiota throughout the orthodontic process.

Oral dysbiosis systematically develops during orthodontic treatment \[35\]\[36\]. Orthodontic appliances interfere with oral hygiene procedures and cause biofilm to accumulate, creating new retention zones, even in subjects who maintain correct oral hygiene \[37\]: * A group benefiting from intensive personalised prevention * A "conventionally monitored" group, with no personalised prevention. The hypothesis is that personalised prevention prevents dysbiosis from taking hold. If this hypothesis is confirmed, the concept could be extended to all patients, beyond orthodontics. Based on the "biological signature" (microbiological and immune), a "risk profile" of patients could be defined, making it possible to better personalise the prevention message, the method applied and the frequency of follow-up. The aim would be to rebalance dysbiosis through a personalised prevention approach tailored to the profile defined. It was decided to explore this hypothesis initially with orthodontic patients because they are "captive", i.e. in the course of treatment requiring regular visits. Prevention is aimed first and foremost at healthy patients, with the aim of maintaining them in good health. The project focuses on young patients undergoing orthodontic treatment

This PMCF study evaluates the safety and performance of OrthoPulse photobiomodulation to accelerate tooth movement during alignment with fixed appliances.

Malocclusions in adolescents may affect oral health related quality of life. The study aims at; 1. Evaluating two instruments measuring oral health related quality of life; "Child Perceptions Questionnaire 11-14" (CPQ 11-14) short form and "Psychosocial Impact of Dental Aesthetics Questionnaire" (PIDAQ). 2. Comparing differences in oral health related quality of life in; 1. adolescents with different types of malocclusion and without malocclusions 2. individuals of different genders and socioeconomic status 3. Longitudinally evaluating differences in oral health related quality of life; 1. before, during and after orthodontic treatment 2. in untreated individuals (without malocclusion) over time