Although of low prevalence, aggressive periodontitis is a rapid destructive form of periodontal disease that initiates at a young age, leading to premature loss of first molars and incisors. Little is known on the mechanisms of this disease. It is imperative to understand mechanisms of disease to establish proper treatment. We have established a controlled study in a comparable population presenting similar aggressive disease characteristics to evaluate the mechanisms of this disease. It is the goal of this study to determine immunological and microbiological mechanisms responsible for the rapid tissue destruction in children with localized aggressive periodontitis and how traditional periodontal intervention affects these mechanisms. Important knowledge gained with this proposal will aid in defining specific treatment approaches to better control disease progression and prevent disease initiation in susceptible individuals.

There a multiple appointments throughout the study which can vary depending upon if a patient has the disease present or not.

If the patient has gum disease: At the initial examination, some samples will be collected: the natural fluid that comes from the gums and the bacteria that are present there will be collected by inserting a piece of paper and a filter strip in the spaces between teeth and gums; blood samples may also be taken by a phlebotomist to evaluate some inflammatory signs of disease and possible genetic markers (about 5 teaspoons at each visit); and a cheek swab may be taken by gently rubbing a little brush into the inside of the cheeks. Patients also may be asked to spit into a container we provide. Tissues from gums that are usually discarded may also be collected during treatment. When patients return for re-evaluation of their gums, all these samples may be collected again at 3, 6, 12, 18 and 24 months after the initial therapy. After 24 months, only clinical examinations may be performed, up to 3 more visits within the following 3 years.

If the patient does not have gum disease: If gums are healthy and the patient does not need treatment, they will be seen every 6 months for examination and cleanings, then sample collections may also be taken at these visits up to 24 months. These sample collections are done to be studied by genetic tests, which will tell us if there are specific genetic markers (inherited markers) associated with this disease, and also other laboratory testing, which will help the researchers identify how the body responds to bacteria. These markers will also be evaluated in family members (parents, grandparents or siblings), when possible, to check for the likelihood of these members developing this disease.

Regardless of the patient's gum condition, investigators will also evaluate current and past dental x-rays to determine if there were signs of this disease in the past.

Investigators may also take photos of the teeth and gums.

Inclusion child/adolescent:

• Male or female, aged 5 to 25
• In good general health as evidenced by medical history
• Diagnosed with localized aggressive periodontitis (LAP), defined by the presence of attachment loss ≥ 2mm and detected bone loss on at least two sites, involving first molars and/or incisors, or
• Periodontally healthy (defined by absence of clinical signs of periodontitis) related or not to LAP participants

Inclusion parent /grandparent:

• Male or female, up to age 90 years
• Parent or grandparent of an enrolled participant with LAP

Exclusion child/adolescent:

• Diagnosed with any systemic diseases or conditions that could influence the progression and/or clinical characteristics of periodontal disease (i.e., immunosuppression, diabetes, neutropenia or blood disorders).
• Patients that have taken antibiotics within the last 3 months* or require antibiotic prophylaxis prior to initial visit.
• Patients that are currently taking medications that could influence the characteristics or response to periodontal treatment (example: immune-suppressive drugs, such as cyclosporine or steroids).
• Smokers (≥10 cigarettes a day for over 6 months)
• Pregnant/lactating women as pregnancy causes gingival changes that could confound study results.
• Any psychiatric conditions that will inhibit participants from proper understanding of study procedures as determined by the PI/clinician investigator.
• Patients may still enroll but will be scheduled for initial visit 3 months later

Exclusion parent/grandparent:

• Patients that have taken antibiotics within the last 3 months* or require antibiotic prophylaxis prior to initial visit.
• Pregnant/lactating women as pregnancy causes gingival changes that could confound study results.
• Any psychiatric conditions that will inhibit participants from proper understanding of study procedures as determined by the PI/clinician investigator.