What Is the Appropriate Antibiotic Administration During Tooth Extractions in Patients Receiving High-Dose Denosumab?

PURPOSE: Medication-related osteonecrosis of the jaw (MRONJ) occasionally occurs following tooth extractions in cancer patients receiving denosumab (Dmab). However, there are currently no established guidelines for perioperative antibiotic administration during tooth extraction in these patients. The primary objective was to develop guidelines for the dose and frequency of antibiotics during tooth extraction by investigating the correlation between the current status of antibiotic administration and the development of MRONJ. METHODS: This study included 68 cancer patients receiving high-dose Dmab who had tooth extractions between 2012 and 2022 at 10 hospitals. The relationship between the way of perioperative antibiotic administration and the development of MRONJ was analyzed. A P-value < .05 was considered significant. RESULTS: There was considerable variability across hospitals and surgeons regarding the type, dosage, and duration of antibiotic administration. Amoxicillin (AMPC) was the most commonly used antibiotic. Focusing exclusively on teeth extracted under AMPC administration, MRONJ developed in 21 out of 123 teeth (17.0%). No significant relationship was found between the development of MRONJ and the dosage or duration of perioperative AMPC administration. CONCLUSION: Perioperative antibiotic administration alone may not be sufficient to prevent MRONJ. Therefore, a single preoperative dose is likely adequate for effective and appropriate AMPC administration.　.

A Novel Imaging Technique for Analyzing Condylar Movement During Mastication in Patients With Jaw Deformities: Four-Dimensional Computed Tomography.

OBJECTIVE: This study aimed to reveal characteristic condylar movements in patients with jaw deformities. STUDY DESIGN: Thirty patients with jaw deformities before surgery were enrolled and instructed to chew a cookie during 4-dimensional computed tomography (4DCT). The distance between the most anterior and posterior positions of the bilateral condyles on 4DCT images was measured and compared among patients with different skeletal classes. Correlations between the condylar protrusion and cephalometric values were also determined. RESULTS: The distances of condylar protrusion during mastication were significantly greater in the skeletal class II group than in the skeletal class III group ( P =0.0002). Significant correlations were found between the distances of condylar protrusion during mastication and the sella-nasion-B point angle ( r =-0.442, P =0.015), A point-nasion-B point angle ( r =0.516, P =0.004), sella-nasion plane to ramus plane angle ( r =0.464, P =0.01), sella-nasion plane to occlusal plane angle ( r =0.367, P =0.047), and condylion-gonion length ( r =-0.366, P =0.048). CONCLUSION: Motion analysis with 4DCT images revealed that condylar movement in patients with retrognathism was larger than in patients with mandibular prognathism. Skeletal structure was therefore correlated with condylar movement during mastication.

Risk factors for pathological fracture in patients with mandibular osteoradionecrosis.

Osteoradionecrosis (ORN) often results in pathological fractures through progression. We aimed to identify the risk factors for pathological fracture in patients with mandibular ORN. Seventy-four patients with mandibular ORN were included in this retrospective study. We investigated various risk factors for pathological fracture in patients with mandibular ORN, including number of mandibular teeth with a poor prognosis each at initial evaluation before radiation therapy (RT) and when fracture occurred, and the proportion of antibiotic administration period in a follow-up duration after RT. The rate of occurrence of pathological fractures in patients with mandibular ORN was 25.7%. The median of duration between RT completion and fracture occurrence was 74.0 months. We found that pathological fracture was significantly associated with a larger number of mandibular teeth with a poor prognosis at initial evaluation before RT (P = 0.024) and when fracture occurred (P = 0.009). Especially, a larger number of mandibular teeth with P4 periodontitis, in other words severe periodontal status, was related to pathological fracture in both timings. The proportion of antibiotic administration period in a follow-up duration was also significant risk factor (P = 0.002). Multivariate analyses showed statistically significant associations between pathological fracture and a larger number of mandibular teeth with a poor prognosis when fracture occurred (hazard ratio 3.669). The patient with a larger number of mandibular teeth with P4 periodontitis may have a risk of not only occurrence of ORN but resulting in pathological fracture by accumulation of infection. Surgeons should consider extraction of those teeth regardless of before/after RT if necessary for infection control.