Impact of Parathyroid Hormone (PTH) on Osseous Cavity

Parathyroid hormone is an endogenous hormone with potent anabolic and catabolic actions in bone. It has recently been approved for the treatment of osteoporosis and is marketed as FORTEO by Eli Lilly and Company. Numerous studies in humans have validated its use to increase bone mineral density and prevent fractures. Interest has also surfaced in its potential application in the treatment of non-osteoporotic fractures and several animal studies have supported this local application. Little is known regarding its use in treating conditions of the oral cavity, but animal studies suggest that bones of the oral cavity are responsive to the anabolic actions of PTH. Furthermore, a recent study indicated that in a canine model, PTH was effective at reversing periodontal bone loss. Studies from our laboratory indicate that patients with hyperparathyroidism (HPT) do not have an increase in periodontal disease as measured by attachment levels. In fact, in our patient population there was an increase in osseous activity in patients with HPT in the form of tori and exostoses (bony protuberances in the oral cavity). This suggests that increased circulating levels of PTH do not adversely impact the oral cavity. Furthermore, in a wound healing animal model of bone regeneration, we found that regenerating intramembranous bone was more responsive to anabolic actions of PTH than endogenous bone of the vertebrae. These studies highlight the potential for PTH to positively impact osseous healing in the oral cavity in response to periodontal therapy.

The study will be double blinded, and patients will be randomized into one of two treatment groups (FORTEO or placebo once/daily). Patients will self-administer drug on a QD schedule, and take Vitamin D and Calcium, PO, QD, for six weeks. Drug administration will begin three days prior to periodontal surgery. Subjects will be followed at post-op, week 3, week 6, month 3, month 6, month 9, and month 12 visits. Clinical effects will be measured by serum collection, gingival crevicular fluid (GCF) sampling, standard dental radiographs, oral exam including perio probing, oral health quality of life questionnaire, and DEXA scans.

Inclusion criteria

• Age range: 30 to 75 years
• Sex: Male and female
• Female patients must be postmenopausal (for at least 2 years), surgically sterilized or utilizing one of the following methods of birth control throughout the trial - IUD, diaphragm, Depo-Provera, Norplant, oral contraceptive with condom or spermicidal gel/foam with a condom, or abstinence
• Patients must be able and willing to follow study procedures and instructions
• Patients must have read, understood and signed an informed consent form
• Patients must have localized or generalized, advanced periodontal disease (American Dental Association Class 4)
• Patients must present with at least 10 teeth in the functional dentition
• Each patient must have at least one tooth with the following criteria to enter the study:

• Periodontal probing depths of > 6 mm to < 14 mm
• Attachment loss of > 6 mm to < 14 mm
• Bleeding on probing

Exclusion criteria

• Patients under 30 years of age
• Female patients who are pregnant (as determined by positive urine pregnancy test at screening) or lactating, or female patients who are of childbearing potential who are not using hormonal, barrier methods of birth control or abstinence.
• Patients who are using hormonal contraceptives must have started the method not fewer than 30 days prior to the screening examination.
• Patients with metabolic bone diseases such as Paget's disease, hypercalcemia, vitamin D3 abnormalities or any other metabolic bone disease including osteoporosis. (If Vitamin D levels are low (> 20 ng/ml - 24 ng/ml), dietary supplementation will be initiated and levels re-evaluated after 4 weeks and reconsidered for inclusion at that time.)
• Patients with prior radiation treatment, bone metastasis or other skeletal malignancy
• Patients on medications that would affect bone metabolism
• Patients with growth hormone deficiency
• Patients with uncontrolled diabetes, sprue, inflammatory bowel disease or other disorders that would affect calcium absorption.
• Patients who are heavy smokers (> 1 pack/day); Patients on bisphosphonates, including Fosamax
• Patients with any form of kidney disease including kidney stones (urolithiasis and nephrolithiasis); and
• Patients on digitalis therapy