Clinical Research Directory

Palatal Guide Wire for Canine Control During Miniscrew-Supported Distalization

When crowded or protruded teeth are treated by removing an upper premolar on each side, the canine (eye tooth) is first moved backward into the space. As it moves, the tooth tends to rotate and tip out of position, and this rotation is one of the hardest movements to correct and most likely to come back later. This study tested a simple addition to the usual treatment: a small passive wire attached to the inner (palate) side of the canine and connected to the back tooth, meant to guide the canine and keep it from rotating, without adding any extra force. Sixteen adolescents who needed an upper premolar removed on both sides took part. Because each person has two sides, every patient received both approaches at once: on one randomly chosen side the guide wire was added, and the other side was treated the same way but without it, serving as that patient's own comparison. This split-mouth design lets each patient act as their own control. The canine was moved backward on both sides using the same light spring and a small bone screw for anchorage. The researchers took dental scans at the start and after one, two, and three months and measured how far each canine moved, how much it rotated and tipped, and whether the back tooth drifted forward. The goal was to find out whether the guide wire reduces unwanted rotation and tipping and affects how quickly the canine moves, without weakening the anchorage.

Comparing 3D-Printed and Milled Titanium Plates in Jaw Surgery (Le Fort I): Accuracy and Operative Time

The purpose of this study is to find out if 3D printed patient-specific titanium plates improve surgical accuracy and decrease operative time compared to milled patient-specific titanium plates in patients having Le Fort I osteotomy for jaw correction. The main questions it aims to answer are: * Do 3D-printed patient specific titanium plates improve surgical accuracy (as measured by ability to transfer the computer plan to the patient's jaw)? * Do 3D-printed patient specific titanium plates decrease operative time when compared to milled patient specific titanium plates? This study will compare two groups of patients. One group will receive 3D printed plates (study group) and the other will receive milled plates (control group) to see if the different methods of making the plates changes the surgical accuracy or operative time. All participants in the study will: * Have Le Fort I osteotomy surgery using patient specific titanium plates (either 3D printed or milled). * Have CT scans before and after surgery to evaluate accuracy. Have their operative time recorded. * Have a post-surgical follow-up to evaluate healing, stability and orthodontic treatment.

Treatment of Skeletal Class II Malocclusion With Modified Twin-Block Appliance With Clear Plates

Patients with skeletal class II malocclusion who have a retracted lower jaw will be treated in this study. The efficacy of clear Plates in the treatment of Skeletal Class II Malocclusion will be assessed. The skeletal, dental and soft tissues changes resulted by this intervention will be studied and compared with the results of Traditional treatment with fixed appliances.

3D Printed Occlusal Splints for Intraoperative Use

A 3D printed intraoperative occlusal splint is a custom-made biocompatible resin guide that allows surgeons properly align a patient's upper and lower dentition during surgery. This alignment further places maxilla and mandible into proper position. An occlusal splint contains outlines maxillary and mandibular dentition allowing the teeth to lock into place with correct alignment. At Johns Hopkins, traditionally hand-made and industry-made 3D printed splints have been used safely. However, prior studies have demonstrated the ability of in-house 3D prints to save time and money compared to industry. In-house models are similarly produced with FDA-clear, biocompatible resin for 3D printing, and maintain equivalent safety for patients compared to industry-made models.

Long-term Stability of Treatment With the Twin Block Appliance

The objective of this observational study is to investigate the long-term stability of treatment with the Twin block appliance in a patient group previously treated with a Twin block appliance. The main questions it aims to answer are: 1. Does treatment with the Twin block appliance give a lasting treatment result or does the bite relapse over time due to different factors such as short treatment time, compliance or the patient's natural growth pattern? 2. How many patients that had received treatment with Twin block appliance required additional treatment with fixed appliances and for what reason? Researchers will compare the patients present bite at (T2) by using study casts and cephalometric x-rays and compare this data with previous registrations made pre- (T0) and post-treatment (T1). Additional factors, such as how much relapse a patient has on average, will also be investigated.

AI-Assisted Versus Conventional Orthodontic Diagnosis and Treatment Planning

This study compared an artificial intelligence-assisted orthodontic diagnostic workflow using WebCeph with a conventional clinician-based workflow. The study included 120 new orthodontic patients treated at Ben Hafeed Dental Center in Sana'a, Yemen, between March 2024 and March 2026. For each participant, the researchers prepared a de-identified package of routine pretreatment records, including clinical findings, extraoral and intraoral photographs, panoramic and lateral cephalometric radiographs, and dental models or digital scans. The same case package was independently assessed using both the artificial intelligence-assisted and conventional workflows. An independent panel of five expert orthodontists reviewed the cases and established the reference standard. The main outcome was agreement with the expert panel for skeletal sagittal classification as Class I, Class II, or Class III. Other outcomes included orthodontic treatment-need grades, premolar extraction decisions, anchorage planning, appliance selection, and the time required to complete each diagnostic workflow. Participation did not alter the routine orthodontic care provided to patients, and final clinical decisions remained the responsibility of the treating orthodontist.

Maxillary Patient Specific Implants in Bimaxillary Orthognathic Surgery

Orthognathic surgery is a type of jaw surgery where a surgeon cuts the bones of the upper and lower jaw and places them better. There are two ways they can put the bones in the correct place and keep them in place after the surgery. One way, called the "conventional method", is to use a 3D-printed guide called a splint to set the bones in the right place and then screw the bones together using metal plates that the surgeon bends into shape to fit during the surgery. Another way is to use a patient-specific implants (PSI) that has been 3D-printed in titanium beforehand that because of its unique shape both places and keeps all the bones in the correct place after they are screwed in. Both ways of doing it are golden standards, meaning they are already approved. Measuring the accuracy of the surgery is done by comparing the positions of the bones after the surgery with the intended positions of those bones, according to the surgical plan. The closer the achieved position of each bone is to the intended position, the more accurate the result. Measuring the stability of the surgery is done by comparing the positions of the bones after the surgery with the positions of the bones two years later. The less the position is changed, the more stable the result. The goal of this clinical trial is to see how accurate and stable PSIs are in orthognathic surgery when the maxilla is split in 3 pieces, and to compare them with the conventional method in patients with overjet or overbite. The main questions it aims to answer are: * Does using PSIs provide accurate movements of the maxilla pieces? * Does using PSIs provide more accurate movements of the maxilla pieces than the conventional method? * Does using PSIs provide stable movements of the maxilla pieces after 2 years? * Does using PSIs provide more stable movements of the maxilla pieces than the conventional method? Participants will get orthognathic surgery as part of their normal orthodontic treatment. Investigators will compare the PSI and conventional groups to see if the PSIs are more accurate than the conventional method.

Facial Aesthetic Analysis Model Based on Clinical Cohort Phenotype to Explore 45° Facial Profile.

Facial aesthetics has always been a complex and subjective concept. The overall facial harmony, along with lip protrusion, which is often a focus for orthodontists, requires evaluation from multiple perspectives. The viewing angle also influences the assessment of facial aesthetics, particularly the judgment of lip protrusion. This study aims to explore the differences in facial fixation patterns and aesthetic evaluations among different populations at specific viewing angles by using digital models to simulate various perspectives.

Microanalysis of Changes in 3D Geometry of Orthodontic Mini-implants

The orthodontic mini-implants used in the study are temporary screws inserted into the bone to provide anchorage for challenging tooth movements that could not be carried out using the patient's own teeth. They are made of a medical grade titanium alloy (Ti6Al4Va), with a length of 8 mm and a diameter of 1.3 mm. After the completion of the treatment phase requiring specific anchorage, they are removed and disposed of as a medical waste. The insertion of the mini-screw is conditioned by the individual treatment plan and the treatment protocol would not differ from the standard treatment. The aim of the project is to analyze changes in the macrogeometry and wear of the surfaces of retrieved orthodontic micro-implants after their clinical use. Upon completion of clinical tasks, the mini-screws will be removed and retrieved for laboratory phase of the study. The laboratory phase will consist of: microscopic and profilometric examinations, as well as scanning before insertion and after removal of the mini-implants, and a clinical phase: the use of previously scanned and sterilized mini-implants in patients participating in the study.

Effects of the Herbst Appliance With Different Anchorages and Twin-Block Appliance in Class II Malocclusion

The purpose of this study is to determine if the Herbst appliance with indirect skeletal anchorage in mini-implants is capable of preventing excessive inclination of the lower incisors at the end of the treatment when compared to the Herbst appliance with dental anchorage and Twin-Block appliances in patients with Class II malocclusion and overjet ≥ 6 mm.

Therapeutic Effects of Class II Elastics on Aligners in Different Vertical Skeletal Patterns

The objective is to compare the dento-alveolar therapeutic effects of wearing class II inter-arch traction elastics on aligners versus multi-brackets in an adult population. The principal hypothesis is no significant difference in therapeutic effects of using inter-arch elastics on aligners versus multi-brackets.