C-terminal telopeptide
In bone physiology, the C-terminal telopeptide (or more formally, carboxy-terminal collagen crosslinks, and known by the acronym CTX) is a serum biomarker used to measure the rate of bone turnover. It can be useful in assisting clinicians to determine a patient's nonsurgical treatment response as well as evaluate a patient's risk of developing complications during healing following surgical intervention.[1] The test used to detect the CTX marker is called the Serum CrossLaps, and it is more specific to bone resorption than any other test currently available.[2]
Bisphosphonate-associated osteonecrosis of the jaw
In the early 2000s, a link between bisphosphonate use and impaired bone physiology was noted.[3][4] The strong inhibition of osteoclast function precipitated by bisphosphonate therapy can lead to inhibition of normal bone turnover, leading to impaired wound healing following trauma (such as dental surgery) or even spontaneous non-healing bone exposure. Because bisphosphonates are preferentially deposited in bone with high turnover rates, it is possible that the levels of bisphosphonate within the jaw bones are selectively elevated.[5]
Risk determination
With the advent of implant dentistry, more dental patients are undergoing therapies in the oral cavity that involve bone healing, such as surgical implant placement and bone grafting procedures. In order to evaluate the risk of osteonecrosis for a patient taking bisphosphonates, the CTX biomarker was introduced in 2000 by Rosen.[2]
CTX
Although a number of surragate biomarkers exist for measuring the metabolic products of bone resorption, the CTX marker was chosen because it is both highly correlated to bone turnover rate and already available for detection in a laboratory test carried out by a major lab testing corporation.[1]
References
- ^ a b Marx, RE, et al. Oral Bisphosphonate-Induced Osteonecrosis: Risk Factors, Prediction of Risk Using Serum CTX Testing, Prevention, and Treatment, J Oral Maxillofac Surg 2007;65:2397-2410
- ^ a b Rosen HN, et al. Serum CTX. A new marker of bone resorption that shows treatment effect more often than other markers because of low coefficient of variability and large changes with bisphosphonate therapy. Calcif Tissue Int 2000;66:100
- ^ Marx RE. Pamidronate (Aredia) and zoledronate (Zometa) induced avascular necrosis of the jaws: A growing epidemic. J Oral Maxillofac Surg 2003;61:1115
- ^ Ruggerio SL, et al. Osteonecrosis of the jaws associated with the use of bisphosphonates: A review of 63 cases. J Oral Maxillofac Surg 2004;62:527
- ^ Ruggiero, SL. Bisphosphonate-related Osteonecrosis of the Jaws. Compendium 2008;29(2):97–105.