The goal of this prospective observational study is to assess the influence of increased body mass index (BMI) on various oral health and orthodontic-related parameters in adolescents undergoing orthodontic therapy (OT) with braces. These parameters include gum inflammation, tooth decalcifications/discolorations, tooth alignment of lower incisors, and various inflammatory and microbiological parameters in the collected saliva and gum fluid of the patients. The primary purpose is to assess if an increased BMI is a risk factor for oral inflammation in adolescents undergoing OT. The main questions it aims to answer are:

1. Do patients with an increased BMI undergoing OT demonstrate increased microbial counts in the saliva compared to patients with normal BMI?
2. Do patients with increased BMI undergoing OT demonstrate increased gum inflammation, tooth discolorations, and higher levels of inflammatory markers in the saliva and gum fluid samples compared to patients with normal BMI? This study will include 2 study groups (patients with increased BMI-test group, and normal weight patients-control group). The participants will be asked to complete a study questionnaire, which will collect information regarding their demographics, their family socioeconomic and educational status, dietary habits, and oral health-related quality of life. The participants will also receive an oral examination (evaluation of their gum health), and they will have their intraoral photos taken, as well as an impression of their lower teeth (to create dental models). A saliva sample will be obtained by asking patients to passively "drool" in a tube, and a gingival fluid sample will be collected from the gums of the lower anterior teeth using thin paper strips. All these study procedures will be conducted at baseline (T1: before bonding of braces), and at an approximately 6-month follow-up visit (T2). Comparisons of these outcomes will be conducted between the two groups and across timepoints.

Inclusion Criteria:

• adolescents (12-17 years old);
• patients scheduled to undergo comprehensive fixed orthodontic therapy (OT) (for at least 6 months with metal braces/wires) on both dental arches;
• patients with increased BMI (≥25.0 Kg/m2) (test-Group);
• patients with normal BMI [18.5-24.99 (Kg/m2)] (control-Group);
• patients with all 6 mandibular anterior teeth present and mild-to-moderate mandibular crowding (<7.5 mm);
• patients and parents/guardians willing to provide signed assent/permission.

Exclusion Criteria:

• self-reported habitual tobacco product users;
• patients with self-reported medical diseases such as hepatic diseases, blood disorders, cardiovascular diseases, HIV, diabetes mellitus, and viral infections;
• patients with craniofacial syndromes and/or cleft lip and palate;
• pregnant and/or lactating females (by self/parent report);
• edentulous individuals;
• patients with active or a history of periodontitis;
• patients having undergone surgical and/or non-surgical periodontal therapy within the past 6 months;
• patients with physical and/or mental/cognitive disabilities who are decisionally-impaired and not able to consent/assent for themselves;
• patients who reported use of medications such as antibiotics, steroids (inhalers and/or pills), non-steroidal anti-inflammatory drugs, and antimicrobial mouth-rinses within the past 3 months or those who require prophylactic antibiotics prior to dental procedures;
• patients undergoing cancer therapy;
• underweight patients (BMI less than 18.5 Kg/m2);
• patients with oral mucosal lesions such as median rhomboid glossitis and lichen planus;
• patients with clinically visible carious teeth.

Adolescent patients undergoing fixed orthodontic therapy at the Eastman Institute for Oral Health, University of Rochester, NY.

IPD will not be shared due to privacy concerns and the risk of re-identification, even with de-identified datasets. Additionally, the scope of consent obtained from participants during the trial does not include provisions for public sharing of individual-level data.