β-CTX Testing Before Tooth Extraction in Patients on Romosozumab (Evenity)
There is no established β-CTX threshold for safe tooth extraction in patients receiving romosozumab, and current evidence does not support using β-CTX testing to guide dental procedures in this population.
Why β-CTX Testing Is Not Recommended for Romosozumab Patients
The β-CTX test was originally proposed for patients on bisphosphonates to predict medication-related osteonecrosis of the jaw (MRONJ) risk, with suggested thresholds of <150 pg/mL indicating high risk and 100-150 pg/mL indicating moderate risk 1, 2, 3. However, even for bisphosphonate patients, the evidence demonstrates that β-CTX testing lacks predictive validity 1, 4.
Critical Evidence Against β-CTX Testing
A prospective study of 163 patients on oral bisphosphonates found that β-CTX is not a valid preoperative test to accurately assess the level of risk of developing ONJ and is not indicated in oral surgery patients 4
Among 950 patients on oral bisphosphonates undergoing tooth extraction, approximately 30% had β-CTX levels <150 pg/mL, but the positive predictive value for developing MRONJ was only 2.09%, meaning 98% of patients with "high-risk" β-CTX values did NOT develop osteonecrosis 2
Multiple studies showed no correlation between β-CTX values and clinical risk factors including age, gender, comorbidities, or medication duration 3
Romosozumab-Specific Considerations
Romosozumab has a fundamentally different mechanism of action than bisphosphonates—it is an anabolic agent that increases bone formation while simultaneously decreasing bone resorption 5. Recent data shows:
β-CTX levels continuously decrease during romosozumab treatment (by approximately 27.8% over 12 months), reflecting reduced bone resorption 5
Procollagen type 1 N-terminal propeptide (P1NP) levels initially increase significantly (+37.9% at 3 months) before returning to baseline, demonstrating the dual anabolic-antiresorptive effect 5
The β-CTX thresholds proposed for bisphosphonates cannot be extrapolated to romosozumab because the drugs have opposite primary mechanisms and different MRONJ risk profiles.
Evidence-Based Approach to Dental Procedures in Romosozumab Patients
Since romosozumab is a bone-modifying agent, follow the established guidelines for this drug class rather than relying on unvalidated biomarker testing:
Pre-Treatment Dental Assessment
A comprehensive dental and periodontal examination with radiographs should be performed before initiating romosozumab therapy 6
Teeth requiring extraction should be removed with at least 2 weeks for healing before starting bone-modifying agent therapy 6
For Patients Already on Romosozumab Requiring Extraction
The 2024 ISOO-MASCC-ASCO guideline provides the most current evidence-based approach for patients on bone-modifying agents:
There is insufficient evidence to mandate discontinuation of bone-modifying agents before dentoalveolar surgery 6
Consider pentoxifylline 400 mg twice daily plus vitamin E (α-tocopherol) 1,000 IU once daily for at least 1 week before and 4 weeks after invasive dental procedures to reduce osteoradionecrosis risk 7
Use meticulous surgical technique with minimal bone trauma 8
Post-Extraction Management
Prescribe chlorhexidine gluconate 0.12%-0.2% mouth rinses twice daily until adequate healing 9
Close follow-up is essential due to potential for delayed healing 9
Use acetaminophen as first-line analgesia rather than NSAIDs 6
Common Pitfalls to Avoid
Do not delay necessary dental extractions based on β-CTX values—this test lacks predictive validity even in bisphosphonate patients and has no established role in romosozumab management 1, 4
Do not assume romosozumab carries the same MRONJ risk as intravenous bisphosphonates—the risk profile differs due to its anabolic mechanism 5
Do not fail to communicate with the prescribing physician about the patient's bone-modifying agent therapy before dental procedures 6
Do not perform extractions without adequate informed consent discussing the theoretical risk of MRONJ, even though the actual incidence with romosozumab is not well-established 6