Do Healing Rates Differ Between Medication-Related and Medication-Unrelated Osteonecrosis of the Jaw?

Background: The healing rates, time to complete healing, effectiveness of operative therapy, and factors associated with healing for medication-related osteonecrosis of the jaw (MRONJ) and medication-unrelated osteonecrosis of the jaw (MUONJ) remain unclear.

Purpose: The study aimed to estimate and compare the healing rates between patients with MRONJ and MUONJ and identify prognostic factors associated with healing.

Study design, setting, sample: A 25-center prospective cohort study was performed-the investigators enrolled patients with ONJ treated using a standardized therapeutic protocol between 2013 and 2016. Patients with a history of radiation therapy to the jaws were excluded.

Predictor variable: The primary predictor variable was the ONJ diagnosis. The secondary predictors involved a set of heterogenous variables grouped into demographic, medical, clinical condition, and perioperative categories.

Main outcome variables: The primary outcome variable was treatment duration, defined as the time (in months) between therapy initiation and site healing, date of the final visit, or loss to follow-up.

Covariates: Not applicable.

Analyses: Descriptive statistics and cumulative healing rates were calculated. P < .05 was considered significant.

Results: The sample comprised 332 subjects with a mean age of 72.3 ± 11.1 years, among whom 116 (34.9%) were male. The MUONJ and MRONJ groups included 41 (12.3%) and 291 (87.7%) subjects, respectively, exhibiting 1-year cumulative healing rates of 92.1 and 47.3% (P < .01), respectively. The hazard ratio for complete healing was 3.7 (95% CI = 2.5 to 5.3, P < .01) in subjects with MUONJ compared with those with MRONJ. The median time to complete healing was 6 (3.8 to 8.2) months in the MUONJ group, while less than half of the subjects in the MRONJ group healed within 12 months. The 1-year cumulative healing rate was 92.1 and 47.3% (P < .01) in the operative therapy and nonoperative therapy groups, respectively.

Conclusions and relevance: MUONJ was associated with better healing rates and a shorter time to healing compared with MRONJ. Operative therapy also showed potential benefits. Decisions for treating ONJ should be based on these findings alongside individual patient needs and conditions.