Please select the eligibility criteria that correspond to the clinical trial below.
Title: Low-Dose Doxycycline Effects on Osteopenic Bone Loss
Brief Summary: The primary purpose of this clinical trial is to determine whether low-dose doxycycline can reduce alveolar bone density loss in postmenopausal osteopenic women with periodontitis and not on hormone replacement therapy (i.e., estrogen deficient).


Options:
A: Inclusion Criteria:

* children at the age of 7 months and their families, recruited from the general population

Exclusion Criteria:

* severe sickness
B: Inclusion Criteria:

* Subjects will be female, postmenopausal and not receiving estrogen replacement therapy.
* Subjects will be 45-70 years old at the time of telephone screening.
* Subjects will have osteopenia (T-score of -1.0 to -2.5) of the lumbar spine or femoral neck as determined by dual-energy absorptiometry (DEXA) scans.
* Subjects will have a history of generalized moderate-advanced periodontitis and will be undergoing periodontal maintenance.
* Subjects will be in good general health and willing to sign the IRB-approved consent form.

Exclusion Criteria:

* Subjects will not have an allergy or hypersensitivity to tetracyclines.
* Subjects will not have diseases or take medications that affect the inflammatory or immune responses (e.g., chronic use of non-steroidal anti-inflammatory drugs) or bone remodeling (e.g., drugs such as prescription estrogens, bisphosphonates, calcitonin or steroids).
* Subjects will not have any medical condition requiring antibiotic premedication (e.g., prosthetic heart valves, prosthetic joints, and mitral valve prolapse with regurgitation) for routine dental therapy.
* Subjects cannot have diabetes mellitus.
* Subjects cannot have had active periodontal therapy (quadrant scaling and root planing or periodontal surgery) within the past year.
* Subjects cannot have osteoporosis (T-score greater than -2.5) of the lumbar spine or femoral neck.
C: Inclusion Criteria:

* 35 years and older
* coronary artery disease
* more than 10 teeth
* chronic periodontitis defined as 2 non-adjacent teeth with probing depth 5+mm and periodontal attachment loss 4+mm

Exclusion Criteria:

* use of antibiotics in the last 6 months
* periodontal therapy in the last 12 months
D: Inclusion Criteria:

* Subjects must be 25 years of age or older
* Three or more periodontal pockets with a probing depth (PD) \> 5mm
* Have at least 20 natural teeth
* Provide informed consent and willingness to cooperate with the study protocol

Exclusion Criteria:

* History of antibiotic use in the previous three months
* Pregnant or lactating females
* Treatment with antihypertensive, antilipemic, antiarrhythmic, and other cardiovascular drugs
* Systemic diseases such as diabetes, HIV/AIDS, liver disease, chronic renal failure, tuberculosis, and autoimmune diseases
* Previous history of cardiovascular disease: Acute myocardial infarct, stable angina, unstable angina, heart failure, atrial fibrillation, atrioventricular block, peripheral vascular disease, cerebrovascular accident
* Patients who received periodontal treatment within the last 3 months
* Patients who require antibiotic prophylaxis before examination or treatment
* Patients with mental retardation and dementia

Answer: B