Medication-related osteonecrosis of the jaw (MRONJ) is a serious side effect of antiresorptive agents and bone-modifying agents. It is of the utmost importance to know the management of the MRONJ to improve the patient's quality of life. This study comprehensively reviews the current definitions of MRONJs, and antiresorptive medications, clinical manifestation and staging, risk factors, treatment strategies, and prevention methods of MRONJ. The disease is defined as an exposure of bone and osteonecrosis of the jaw in the oral cavity for at least 8 weeks in patients taking antiresorptive drugs or antiangiogenic agents and with no history of radiotherapy treatment of the jaws. Many articles have reported risk factors associated with MRONJ such as systemic diseases, antiresorptive medication, oral infection, and poor oral hygiene. Osteonecrosis and antiresorptive medications including bisphosphonate and denosumab have been strongly associated, but the pathology of MRONJ is only limited. Hence, an effective and appropriate management and treatment for MRONJ is still to be defined. The objectives of MRONJ treatment are to minimize osteonecrosis and relieve symptoms, and many treatments are suggested from conservative treatment to marginal resection, but this remains controversial. Appropriate treatment of MRONJ remained difficult, although many studies are being covered.

Purpose: The purpose of this study was to investigate whether various saliva collection methods affect the observed salivary microbiome and whether microbiomes of stimulated and unstimulated saliva and plaque differ in richness and diversity. Methods: Seven sampling methods for unstimulated saliva, stimulated saliva, and plaque samples were applied to six orally and systemically healthy participants. Bacterial 16S ribosomal RNA genes of 10 major oral bacterial species, namely, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia, Prevotella nigrescens, Streptococcus mitis, Streptococcus sobrinus, and Lactobacillus casei, were analyzed by real-time polymerase chain reaction. We comprehensively examined the dependence of the amount of bacterial ribosomal DNA (rDNA), bacterial-community composition, and relative abundance of each species on sample collection methods. Results: There were significant differences in the bacterial rDNA copy number depending on the collection method in three species: F. nucleatum, P. nigrescens, and S. mitis. The species with the highest richness was S. mitis, with the range from 89.31% to 100.00%, followed by F. nucleatum, P. nigrescens, T. denticola, T. forsythia, and P. intermedia, and the sum of the proportions of the remaining five species was less than 1%. The species with the lowest observed richness was P. gingivalis (<0.1%). The Shannon diversity index was the highest in unstimulated saliva collected with a funnel (4.449). The Shannon diversity index was higher in plaque samples (3.623) than in unstimulated (3.171) and stimulated (3.129) saliva and in mouthwash saliva samples (2.061). Conclusions: The oral microbial profile of saliva samples can be affected by sample collection methods, and saliva differs from plaque in the microbiome. An easy and rapid technique for saliva collection is desirable; however, observed microbial-community composition may more accurately reflect the actual microbiome when unstimulated saliva is assayed.

Purpose: This study aimed to broaden our understanding of the predisposing factor and treatment of dislocation by analyzing and evaluating the morphology of the articular eminence (AE) in subjects with temporomandibular joint (TMJ) dislocation using cone beam computed tomography (CBCT). Methods: The subjects were divided into two groups: dislocation (31 subjects) and control (32 subjects). CBCT was used to examine 126 TMJs in 63 subjects (26 males, 37 females). The height, width, and posterior slope of the AE were measured in the parasagittal plane. The posterior slope was measured using the "top-roof line angle (TR angle)" method and the "best-fit line angle (BF angle)" method. The AE on the left side (AEL) and the AE on the right side (AER) of the subjects in the dislocation group were separately analyzed and compared with the control group after taking measurements. The average value of both sides was used when comparing with subjects with bilateral dislocation. Results: Dislocations were more frequent in females (67.7%) than in males (32.3%). The dislocation group showed a gentler TR angle than the control group in the AER and in the average of AE on the both sides (AEB). The same group also showed a wider AE in the AEL and the AER (p<0.05). In subjects with unilateral dislocation, the width of the AE with dislocation was narrower and the TR angle and BF angle was steeper than the other side without dislocation (p<0.05). Conclusions: In subjects with unilateral TMJ dislocation, the posterior slope of the AE is steeper, and the width is narrower at the site of dislocation compared to the site without dislocation. However, in subjects with bilateral TMJ dislocation, AEB were wider, and the mean value of the posterior slope of AEB was gentler than that of the control group.

Purpose: The purpose of this study was to analyze the extent of awareness and understanding of college students on temporomandibular disorder (TMD) and to search for avenues for raising public awareness and improving knowledge about TMD. Methods: One thousand and one hundred and twenty one college students in Gyeonggi-do completed a questionnaire related to awareness, experience and knowledge of TMD and collected data were analyzed by Pearson's chi-squared test. Results: Women were more significantly aware of the terms, 'TMD' (p<0.001) and 'jaw joint disease' (p<0.001) than men. Third graders were more significantly aware of the terms, 'TMD' (p<0.001) and 'jaw joint disease' (p<0.001) than any other graders. Third graders the most frequently chose to visit department of dentistry for the treatment of TMD among three graders (p<0.001). Women more frequently chose to visit department of dentistry for the treatment of TMD than men (p<0.001). Health field subjects were more significantly aware of the terms, 'TMD' (p<0.001) and 'jaw joint disease' (p<0.001) than non health field subjects. Having more frequently visited department of dentistry for the treatment of TMD than non health field subjects (p<0.001), health field subjects more frequently chose to visit department of dentistry for the treatment of TMD in the future (p<0.001). Conclusions: The level of awareness and knowledge of TMD was higher in women college students, health field subjects and third graders than men college students, non health field subjects and the rest of two graders, respectively. The higher the level of experience and education of the subject, the more aware the subject was of TMD. Therefore publicity activities and education through various routes are required to raise public awareness and knowledge of TMD. In addition, it is necessary to inform general public of the dentistry specialized for the accurate diagnosis and standardized treatment of TMD.

Purpose: Most cases of oral and maxillofacial infections are usually easily treated by proper diagnosis, elimination of causative factors, and antibiotic therapy. However, the emergence and the increase of multidrug-resistant bacteria make treatment challenging. "ESKAPE" pathogens are the most common opportunistic organisms in nosocomial infections and have resistant to commonly used antibiotics. There are many medical reviews of ESKAPE pathogens, but few in dentistry. This study focuses on oral and maxillofacial infection especially with ESKAPE pathogens. The purpose of this study is to prepare feasible data about tracing and treatment of infection related to pathogens that may be beneficial to clinicians. Methods: A total of 154 patients with oral and maxillofacial infections were reviewed by analyzing retrospectively hospitalized data in the Department of Oral and Maxillofacial surgery, Chosun University Hospital, Korea, past 5 years from January 2014 to December 2018. Based on the medical records and microbiological tests, the results were divided into two groups: infections with ESKAPE pathogens and other bacteria. Results: A total of 22 species were isolated from 154 patients. The proportion of ESKAPE pathogens among all bacterial isolates collected from infected patients was 39.6%. Causative factors, especially in post-operative infection, showed a statistically significant correlation to ESKAPE infections (29 cases). And average of treatment period in ESKAPE group was longer than non-ESKAPE groups. Overall, Klebsiella pneumoniae (60.7%) was the most frequently isolated ESKAPE pathogen. And high antibiotic resistance rates had been detected in the ESKAPE during the five-year period. Conclusions: Infections with ESKAPE pathogens are now a problem that can no longer be overlooked in Dentistry. Based on results of this study, ESKAPE pathogens were highly associated with post-operative or opportunistic infections. Clinicians should be careful about these antibiotic resistant pathogens and use appropriate antibiotics to patients while having dental treatments.

Recent case studies raised the possibility that cutaneous and oral mucosal manifestations may be associated with the coronavirus disease 2019 (COVID-19) vaccination. A healthy 43-year-old male presented an acute aphthous stomatitis following Moderna COVID-19 vaccination. This rare case draws attention to a potential etiologic effect for oral mucosal manifestation from COVID-19 vaccination. Further investigation to shed light on prevalence and pathophysiologic association of this oral lesion and COVID-19 vaccination deserve attention.

Subchondral cysts are frequently encountered in patients with temporomandibular joint osteoarthritis (TMJ OA), particularly in advanced stage. Subchondral cysts within osteoarthritis are typically lying adjacent to the joint surface where initial load bearing occurs during activity and have been associated with greater pain and disease progression. Although the etiology of these cysts remains uncertain, recently studies report that the induction of the subchondral bone mechanical stress caused subchondral cysts. Repeated overloading leads to further deterioration of subchondral bone which render subchondral bone structure more fragile, increase the risk of osteoarthritis progress. The purpose of this study was to assess the effect of conservative treatment and longitudinal osseous changes of a large subchondral cyst in a mandibular condyle in a symptomatic TMJ OA patient.