Background: Antiresorptive medications for osteoporosis increase the risk of medication-related osteonecrosis of the jaw (MRONJ), particularly following dentoalveolar surgery. Bone turnover markers (BTMs), including C-terminal telopeptide of type 1 collagen (CTX), N-terminal propeptide of type I procollagen (P1NP), and N-terminal telopeptide of type 1 collagen (NTX), are useful for assessing bone metabolism in these patients. This study evaluated the value medication cessation, BTMs and age in risk of MRONJ.
Methods: Prospective statistically powered study of 56 patients, average age of 75.54 years (SD=8.67), on denosumab referred to a maxillofacial surgeon for elective dentoalveolar surgery. Serum CTX, P1NP, and urinary NTX were measured: before the drug holiday (initial test), at the time of surgery (PreOp test), and before resuming denosumab (PostOp test). Analysis included correlations between BTMs, time off medication and age.
Results: CTX and NTX predicted ONJ (4 patients). Strong positive correlations were found between BTMs (correlation coefficients of 0.846 (CTX and P1NP), 0.837 (CTX and NTX), and 0.799 (P1NP and NTX)). Linear regression models revealed NTX and P1NP were good predictors of CTX levels. The model using both markers explained 74.1% of the variability in CTX (R-squared=0.741), with an average error (RMSE) of 209.15. Time since medication cessation had a significant impact on CTX levels (p<0.001). Each additional day off medication associated with increase in CTX. Age did not significantly influence BTM levels across the 3 study checkpoints or over time.
Conclusion: We demonstrated strong correlations between the BTMs: CTX, P1NP, and NTX in patients on denosumab therapy who require dental extractions. Low CTX and NTX are best predictors of MRONJ. NTX and P1NP predicts CTX levels with reasonable accuracy. Longer duration off medication significantly improves BTM levels. These findings provide valuable insights for BTM and timing of dentoalveolar surgery. Age does not appear to be significant.