Clinical Research Directory

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.

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.

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.

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.