This study will examine how marijuana use can affect oral bacteria and brain health in people with HIV and without HIV. Early studies show that marijuana users have more oral bacteria than non-marijuana users. The increase in bacteria is believed to affect brain health. Participation in the study will be one visit. The visit will take approximately 120 minutes.

Maxillary expanders are orthodontic appliances that are commonly used to expand the upper jaw. The purpose of this study will be to compare the effects produced by two different maxillary expanders in children 8-13 years old. The first type of expander is made by hand in an orthodontic laboratory, and the second type of expander is designed on a computer and printed using 3D printers. Both expanders are already used in the MUSC Orthodontics Clinic. The purpose of this study is to see if the 3D printed expander is as effective as the traditional expander made by hand in the laboratory, with more comfort to the patient. Patients participating in the study will be randomly assigned to one of two groups: group A will be treated with a laboratory-made maxillary expander, and group B with a 3D-Printed maxillary expander. Information will be collected on the participants' standard clinical follow-up visits including photos, x-rays, and dental photo scans over the course of 6 months to see how the expander is working. In addition, as part of the research study, the participant will be asked to complete online questionnaires with assistance from parents or guardians about his/her quality of life and perception of possible pain and discomfort at different time points. The potential benefits of this study include the use of 3D technology to improve the quality of the orthodontic treatment, with more comfort to the patient.