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Recent Submissions
Clinical and Psychological Profiles of Patients With Subclinical Versus Self-Reported Painful Temporomandibular Disorders
(2025-01-01) Chattrattrai T.; Jariyasakulroj S.; Mitrirattanakul S.; Chattrattrai T.; Mahidol University
Objective: To compare clinical examination findings, functional limitations, and psychological profiles between patients with subclinical temporomandibular disorders (TMD) and those with self-reported painful TMD. Materials and Methods: This cross-sectional study investigated 98 subclinical TMD patients and 262 self-reported painful TMD patients attending a specialised orofacial pain clinic. Subclinical TMD was defined as positive palpation findings without muscle or joint pain complaints. Self-reported painful TMD required both pain complaints and positive clinical findings. Validated questionnaires assessed jaw functional limitations (JFLS-20), depression (PHQ-9), stress (SPST-20), and oral behaviours (OBC). Statistical analysis used Mann–Whitney U tests and chi-square tests with Bonferroni correction. Results: Self-reported painful TMD patients were significantly older (median age 39 vs. 31 years, p = 0.003), showed greater jaw functional limitations (JFLS global score: 1.88 vs. 0.75, p < 0.001), and higher depression scores (PHQ-9: 1.0 vs. 0.0, p < 0.001). Sleep bruxism frequency differed significantly between groups (p < 0.001), with subclinical patients more commonly reporting frequent sleep bruxism. No significant differences were found in stress levels, overall oral behaviours, or daytime clenching frequency. Conclusions: Patients with self-reported painful TMD demonstrate distinct clinical profiles characterised by greater functional impairment and psychological distress compared to subclinical cases. Clinical Relevance: These findings suggest different phenotypes within the TMD spectrum that may require tailored clinical approaches. Longitudinal studies are needed to determine whether subclinical TMD represents an early stage or a distinct entity.
Intracranial Pressure Monitoring and Management
(2022-06-09) Viarasilpa T.; Francoeur C.L.; Mayer S.A.; Viarasilpa T.; Mahidol University
Intracranial hypertension is a life-threatening condition that if left unchecked can lead to brain herniation, cerebral ischemia, and brain death. Intracranial pressure (ICP) monitoring is frequently helpful for patient management. If placed, the monitor should be inserted in comatose patients at high risk for elevated ICP. ICP values, trends, and waveforms should be analyzed in conjunction with cerebral perfusion pressure (CPP) to guide therapy. Patients with elevated ICP can be managed using a tiered strategy that emphasizes cerebral spinal fluid drainage, sedation, and CPP optimization (tier one) prior to initiating bolus osmotherapy, hyperventilation, or paralysis (tier two). Multimodality monitoring therapy is a promising strategy that can detect secondary brain injury early and allow individualized treatment. Tier-three strategies for superrefractory ICP elevation include decompressive craniectomy, hypothermia, and pentobarbital infusion. Of these, craniectomy appears to be the most effective measure for reducing mortality, especially in younger patients.
Evaluation of Streptococcus mutans strains possessing genes encoding collagen-binding proteins in the Japanese population
(2025-12-01) Okuda M.; Suehiro Y.; Lapirattanakul J.; Naka S.; Matsumoto-Nakano M.; Nomura R.; Okawa R.; Nakano K.; Okuda M.; Mahidol University
Background: Streptococcus mutans harbors collagen-binding protein genes, namely cnm and cbm, which are implicated in its virulence and pathogenicity in both oral and extraoral infections. Although both genes were initially identified in S. mutans isolated from Japanese populations, their geographical prevalence, distribution, and genetic relatedness within Japan remain largely unexplored. This study investigates the prevalence of S. mutans strains carrying cnm and cbm genes across Japan, correlates these findings with clinical data, and analyzes the genetic relatedness of cnm-positive and cnm-negative strains using multilocus sequence typing (MLST). Methods: Dental plaque specimens were collected from 1248 individuals from eight Japanese cities (Hiroshima, Fukuoka, Nagasaki, Niigata, Okayama, Osaka, Tokushima, and Tokyo) and plated on selective medium for S. mutans isolation. S. mutans was confirmed in 523 subjects by colony morphology and PCR using species-specific primers, and the presence of the cnm and cbm genes was determined by PCR with gene-specific primers. Demographic (age, sex) and oral examination (caries prevalence, caries experience, number of teeth) data were recorded. MLST was employed to genotype selected cnm-positive and cnm-negative S. mutans strains to assess their clonal relationships. Results: Among 523 subjects possessing S. mutans (aged 3–90 years), we detected cnm-positive strains in all cities; specifically, the prevalence ranged from 5.5% in Okayama to 25.0% in Tokushima. In contrast, cbm-positive strains were less common and undetectable in some regions. Furthermore, subjects harboring cnm-positive S. mutans were significantly older (p = 0.002) and had higher caries prevalence and experience (p < 0.001). MLST revealed evolutionary relationships among cnm-positive strains across the cities but no discernible region-specific clustering. Clonal relationships partially reflected cnm gene distribution, particularly for exclusively cnm-positive or cnm-negative clonal complexes, but inconsistencies involving serotypes and cnm presence within some clonal complexes and sequence types were also noted. Conclusions: The cnm-positive S. mutans strains are widely distributed throughout Japan and are associated with increased age and caries burden. Although core genome analysis revealed some clonal patterns, the non-uniform distribution of the non-core cnm gene is likely influenced by horizontal gene transfer, providing S. mutans with adaptive advantages irrespective of its core genetic background or serotype.
Air quality and health impacts in Nepal’s urban valley: PM2.5pollution patterns and public health risks
(2025-12-01) Bhatta J.; Acharya S.R.; Thapa S.; Tularag P.; Adhikari S.; Bhatta J.; Mahidol University
The Kathmandu Valley exemplifies how monsoon climate dynamics create deceptive pollution patterns that mask persistent public health threats. Seasonal PM2.5 variability suggests that the monsoon "relief" pollution, but even the cleanest periods pose severe health risks. We analyzed 1,710 daily PM2.5 observations spanning 2020-2024 using machine learning and advanced statistical methods, developing predictive models, identifying meteorological thresholds, and assessing health risks across Nepal's five distinct seasons. PM2.5 measurements were obtained using a BAM-1020 Beta Attenuation Monitor with rigorous quality control procedures ensuring 97.3 % data completeness. Extreme seasonal variability was observed, ranging from 51.5 ± 30.5 μg/m3during the monsoon to 146.7 ± 27.3 μg/m3in winter; however, across all seasons, the values were 3.4-9.8 times higher. Temperature exhibited the strongest PM2.5 control (r = -0.710, p < 0.001), while Random Forest models achieved superior prediction accuracy (R² = 0.941, RMSE = 12.04 μg/m3, MAPE = 10.3 %) compared to linear regression (R² = 0.572) following systematic hyperparameter optimization across 18 parameter combinations using 5-fold cross validation (CV R2= 0.933 ± 0.017). Critical meteorological thresholds were identified: rainfall exceeding 15.9 mm/day and wind speed exceeding 5.8 m/s reduce pollution, but not sufficiently for safety. Concentrations show a systematic annual increase of 6.7 μg/m3(p < 0.001), with all vulnerable populations facing year-round health risks (hazard quotients >1), and people with asthma experiencing the highest risks (HQ = 4.4 in winter). Multi-year patterns demonstrate that monsoon washing effects, while substantial, cannot compensate for extreme baseline pollution levels, revealing the urgent need for emission controls that transcend seasonal pollution management approaches.
Clinical characteristics and outcomes of bites from rhabdophis siamensis: a retrospective study
(2025-01-01) Tongpoo A.; Tansuwannarat P.; Saowaprut P.; Vasaruchapong T.; Likitrujanont N.; Rittilert P.; Blessmann J.; Trakulsrichai S.; Tongpoo A.; Mahidol University
Introduction: Among medically important non-front-fanged colubroid snakes in Asia, the bites from Rhabdophis subminiatus (red-necked keelback) and Rhabdophis tigrinus (the yamakagashi) can cause severe systemic hematotoxic effects. Clinical data from these envenomations are limited. Rhabdophis siamensis (Siamese red-necked keelback), which was previously classified as a subspecies of Rhabdophis subministus, inhabits Thailand. This study aimed to describe the clinical effects of Rhadophis species envenomation in Thailand, including data on treatments and outcomes. Methods: This 15-year retrospective study examined data from the Ramathibodi Poison Center from 2008 to 2022. The objectives were to summarize the clinical characteristics, treatments, and outcomes following Rhabdophis siamensis bites. Results: Fifty-three patients (50.9% males, median age 37 years, range 1–79 years) were included. Fang marks were observed in 84.9%. Thirteen patients experienced local effects, including wound swelling (eight patients) and bleeding at the bite site (eight patients). Coagulopathy, thrombocytopenia, and systemic bleeding occurred in nine, five, and three patients, respectively. All patients with thrombocytopenia exhibited coagulopathy. Wound swelling and bleeding at bite sites were present in patients with systemic effects (coagulopathy), more frequently than in those who did not have them. Non-specific hematotoxic antivenom was administered to nine patients, and three patients received blood components. The median length of hospital stay was 1 day (range 1–14). No deaths were reported. Discussion: Local and systemic effects following Rhabdophis siamensis bites were not frequently observed. Systemic bleeding rarely occurred. The antivenoms available in Thailand are not produced to neutralize the venom Rhadophis species snakes. We believe that they are unlikely to be effective and should not be used for this type of snakebite. Conclusions: Local and systemic hematotoxic effects were observed in some patients. Systemic bleeding occurred in a few patients. No fatalities were observed.