Dispersion of Aerosols Generated during Dental Therapy.

The novel coronavirus pandemic has resulted in an urgent need to study the risk of infection from aerosols generated during dental care and to conduct a review of infection controls. However, existing studies on aerosol particles related to dental treatment have mainly evaluated only the scattering range. Few studies have been conducted on the specifics of the generation of aerosol particles in clinical settings, their mechanisms and patterns of distribution throughout open or enclosed spaces, the duration that they remain suspended in air, and the amount and size of particles present. To minimize the influence of background particles, laser lights, a high-sensitivity camera, and particle counters were used in a large super clean laboratory to investigate the dynamics of aerosols generated during the operation of dental micromotors. The results indicate that aerosols tend to scatter upward immediately after generation and then gradually disperse into the surroundings. Most of the particles are less than 5 µm in size (only a few are larger), and all particles are widely distributed over the long term. Our research clearly elucidates that aerosols produced in dental care are distributed over a wide area and remain suspended for a considerable time in dental clinics before settling.

Risk Factors for Post-Tooth Extraction Complications in HIV-Infected Patients: a Retrospective Study.

We aimed to assess the rate and risk factors of postoperative complications following tooth extraction in HIV-infected patients by CD4 count. The study participants were 231 HIV-infected patients who underwent tooth extraction at our institution between January 2007 and December 2011. Blood test results, underlying diseases, surgical site, extraction method, and postoperative complication data were obtained from medical records. Potential risk factors of postoperative complications were analyzed using multivariate logistic regression. Patients were divided into two groups: 61 (26%) patients with a CD4 count < 200/µL, and 170 (74%) with a CD4 count ≥ 200/µL. Of the 231 patients, 12 (5.2%) developed postoperative complications (alveolar osteitis, n = 10; surgical site infection, n = 2). The rate of complications did not differ between the CD4 < 200/µL group (1.6%) and the CD4 ≥200/µL group (6.5%) (adjusted odds ratio [aOR]: 9.328, 95% confidence interval [CI]: 0.470, 185.229; P = 0.1431). Surgical extraction with bone excavation, but without CD4 count, was identified as a risk factor for post-extraction complications (aOR: 22.037, 95% CI: 1.519, 319.617; P = 0.0234). A low CD4 count is not a risk factor for post-extraction complications in patients with HIV infection. We conclude that tooth extraction should be performed based on dental/oral conditions, and not delayed until CD4 count improvement.

Survival case of rhinocerebral and pulmonary mucormycosis due to Cunninghamella bertholletiae during chemotherapy for acute myeloid leukemia: a case report.

A 42-year-old man diagnosed with acute myeloid leukemia complained of progressive swelling of the right side of his face with pain 11 days after the third cycle of consolidation therapy with high-dose arabinosylcytosine-cytarabine. Head and neck magnetic resonance imaging showed a mass lesion in his right maxillary sinus with parapharyngeal involvement, which included the right masseter muscle, intraorbital involvement, and an abscess in his brain. Chest computed tomography revealed peribronchial small nodules in his right upper lobe and a necrotic tumor in his right lower lobe. Molds identified as Cunninghamella bertholletiae were isolated from the necrotic ulcer. According to these results, chemotherapy for leukemia was discontinued. High-dose liposomal amphotericin (10 mg/kg/day) was initiated. Because renal dysfunction occurred, the dosage was decreased to 6 mg/kg and combined with 150 mg/day micafungin. Debridement of necrotic tissue in the right maxillary sinus and establishment of the fenestration between the sinus and oral cavity were performed. Subsequently, brain and lung lesions were surgically removed. Rhinocerebral mucormycosis was successfully treated without relapse over 3 years by a 112-day course of intravenous anti-fungal therapy and 223-day course of terbinafine and partial surgical removal, respectively, to maintain masticatory and ocular functions. To our knowledge, there has been no other report of a long-term survival case of rhinocerebral mucormycosis due to C. bertholletiae.