Eun Joo Choi

Molecular approaches for the detection and monitoring of microbial communities in bioaerosols: A review.

Bioaerosols significantly affect atmospheric processes while they undergo long-range vertical and horizontal transport and influence atmospheric chemistry and physics and climate change. Accumulating evidence suggests that exposure to bioaerosols may cause adverse health effects, including severe disease. Studies of bioaerosols have primarily focused on their chemical composition and largely neglected their biological composition and the negative effects of biological composition on ecosystems and human health. Here, current molecular methods for the identification, quantification, and distribution of bioaerosol agents are reviewed. Modern developments in environmental microbiology technology would be favorable in elucidation of microbial temporal and spatial distribution in the atmosphere at high resolution. In addition, these provide additional supports for growing evidence that microbial diversity or composition in the bioaerosol is an indispensable environmental aspect linking with public health.

Complications in endoscopic-assisted open reduction and internal fixation of mandibular condyle fractures.

Endoscopic-assisted open reduction and internal fixation (EAORIF) of subcondylar fractures is minimally invasive, provides excellent visibility without a large incision, and reduces surgical scarring and the risk of facial nerve injury. This study evaluated the complications associated with EAORIF. Twenty-six patients underwent EAORIF for mandibular condyle fractures. The postoperative follow-up period was longer than 6 months. We analyzed associations between the complication incidence and the number of fixation plates, accompanying mandibular fractures, and age. Eighteen (69.2%) and 6 (23.1%) patients had temporary (<3 months after surgery) and long-term (>6 months after surgery) complications, respectively. Patients older than 30 years had complications more frequently than those younger than 30 years. Complication rates were similar for different numbers of fixation plates and among patients with and without accompanying mandibular fractures. EAORIF is a reliable technique for treating condylar fractures, regardless of patient age, number of fixation plates, or accompanying mandibular fractures. However, improvements are needed to reduce long-term complications.

Risk prediction for malignant conversion of oral epithelial dysplasia by hypoxia related protein expression

Aims: Increased aerobic glycolysis is a unique finding in cancers and hypoxia-related proteins are associated with aerobic glycolysis. Therefore, we aimed to investigate whether hypoxia-related proteins can be predictive markers for malignant conversion of oral premalignant lesions with epithelial dysplasia (OED). Methods: Expression of HIF-1&agr;, Glut-1 and CA9 were detected in clinical samples of eight normal oral mucosa, 85 transitional areas of oral squamous cell carcinoma (OSCC) and 28 OED with or without malignant conversion using immunohistochemistry and were also comparatively detected in immortalised human oral keratinocyte (IHOK) and OSCC cell lines under hypoxia using immunoblotting. Results: Sequential expression of HIF-1&agr;, Glut-1 and CA9 was found both in transitional areas of OSCC and cell lines of IHOK and OSCC under hypoxia, supporting hypoxia-aerobic glycolysis-acidosis axis. Expression of all proteins showed significant association with malignant conversion of OED and CA9 was an independent risk factor of malignant transformation of OED. But the predictability of malignant transformation was improved when all three proteins were applied together. Conclusion: High expression of CA9 was an independent predictive marker of malignant conversion. Moreover, the combined application of these three proteins may be useful to assess the risk of malignant conversion of OED.

Sclerosing polycystic adenosis of the parotid gland.

Sclerosing polycystic adenosis (SPA) is an uncommon salivary gland lesion similar to fibrocystic disease and adenosis of the mammary glands. To our knowledge, 51 cases of SPA have been reported in the literature to date. Sclerosing polycystic adenosis is well circumscribed, yet not encapsulated, and has sclerotic and irregularly defined lobules composed of abundant hyalinized collagen with ductal, acinar hyperplasia and areas of apocrine metaplasia. Focal cystic spaces within a dense fibrotic stroma are also characteristic features of this lesion. Most of the known cases occurred mainly in the parotid gland. In this article, we describe a case of SPA occurring in the parotid gland of a 47-year-old male patient.

Modified Mandibulotomy Technique to Reduce Postoperative Complications: 5-Year Results

Purpose To review the 5-year outcomes of our modified mandibulotomy technique. Retrospective review of a tertiary level oral cancer center. Materials and Methods During a 5-year period, 30 patients who had a uniform surgical technique consisting of a lower lip-splitting, modified stair-step osteotomy with thin saw blade and osteotome after plate-precontouring and combination fixation with monocortical osteosynthesis (miniplate) and bicortical osteosynthesis (maxiplate and bicortical screws), with at least 14 months postoperative follow-up, were selected and reviewed retrospectively. Results There were 8 women and 22 men with an average age of 56.5 years. All the patients involved malignancies were squamous cell carcinoma. The main primary sites of the those who underwent a mandibulotomy were the tonsil, the base of tongue, the oral tongue, the retromolar pad area, and others. Others included buccal cheek, floor of mouth, and soft palate. 23 patients received postoperative radiation therapy, and among whom 8 patients also received chemotherapy. Total four (13%) mandibulotomy-related complications occurred, only two (6.7%) requiring additional operation under general anesthesia. Conclusion Our modified mandibulotomy meets the criteria for an ideal mandibulotomy technique relatively well because it requires no intermaxillary fixation, can precise preserve the occlusion in a precise way, allows early function, requires no secondary procedures, and has few complications.

Bone Healing Properties of Autoclaved Autogenous Bone Grafts Incorporating Recombinant Human Bone Morphogenetic Protein-2 and Comparison of Two Delivery Systems in a Segmental Rabbit Radius Defect

Purpose: This study aims to validate the effect of autoclaved autogenous bone (AAB), incorporating Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2), on critical-sized, segmental radius defects in rabbits. Delivery systems using absorbable collagen sponge (ACS) and fibrin glue (FG) were also evaluated. Methods: Radius defects were made in 12 New Zealand white rabbits. After autoclaving, the resected bone was reinserted and fixed. The animals were classified into three groups: only AAB reinserted (group 1, control), and AAB and ErhBMP-2 inserted using an ACS (group 2) or FG (group 3) as a carrier. Animals were sacrificed six or 12 weeks after surgery. Specimens were evaluated using radiology and histology. Results: Micro-computed tomography images showed the best bony union in group 2 at six and 12 weeks after operation. Quantitative analysis showed all indices except trabecular thickness were the highest in group 2 and the lowest in group 1 at twelve weeks. Histologic results showed the greatest bony union between AAB and radial bone at twelve weeks, indicating the highest degree of engraftment. Conclusion: ErhBMP-2 increases bony healing when applied on AAB graft sites. In addition, the ACS was reconfirmed as a useful delivery system for ErhBMP-2.

Protrusive maxillomandibular fixation for intracapsular condylar fracture: a report of two cases

Clinical limitations following closed reduction of an intracapsular condylar fracture include a decrease in maximum mouth opening, reduced range of mandibular movements such as protrusion/lateral excursion, and reduced occlusal stability. Anteromedial and inferior displacement of the medial condyle fragment by traction of the lateral pterygoid muscle can induce bone overgrowth due to distraction osteogenesis between the medial and lateral condylar fragments, causing structural changes in the condyle. In addition, when conventional maxillomandibular fixation (MMF) is performed, persistent interdental contact sustains masticatory muscle hyperactivity, leading to a decreased vertical dimension and premature contact of the posterior teeth. To resolve the functional problems of conventional closed reduction, we designed a novel method for closed reduction through protrusive MMF for two weeks. Two patients diagnosed with intracapsular condylar fracture had favorable occlusion after protrusive MMF without premature contact of the posterior teeth. This particular method has two main advantages. First, in the protrusive position, the lateral condylar fragment is moved in the anterior-inferior direction closer to the medial fragment, minimizing bone formation between the two fragments and preventing structural changes. Second, in the protrusive position, posterior disclusion occurs, preventing masticatory muscle hyperactivity and the subsequent gradual decrease in ramus height.