Allylamine coating on zirconia dental implant surface promotes osteogenic differentiation in vitro and accelerates osseointegration in vivo.

OBJECTIVES: The glow discharge plasma (GDP) procedure has proven efficacy in grafting allylamine onto zirconia dental implant surfaces to enhance osseointegration. This study explored the enhancement of zirconia dental implant properties using GDP at different energy settings (25, 50, 75, 100, and 200 W) both in vitro and in vivo. MATERIALS AND METHODS: In vitro analyses included scanning electron microscopy, wettability assessment, energy-dispersive X-ray spectroscopy, and more. In vivo experiments involved implanting zirconia dental implants into rabbit femurs and later evaluation through impact stability test, micro-CT, and histomorphometric measurements. RESULTS: The results demonstrated that 25 and 50 W GDP allylamine grafting positively impacted MG-63 cell proliferation and increased alkaline phosphatase activity. Gene expression analysis revealed upregulation of OCN, OPG, and COL-I. Both 25 and 50 W GDP allylamine grafting significantly improved zirconia's surface properties (p < .05, p < .01, p < .001). However, only 25 W allylamine grafting with optimal energy settings promoted in vivo osseointegration and new bone formation while preventing bone level loss around the dental implant (p < .05, p < .01, p < .001). CONCLUSIONS: This study presents a promising method for enhancing Zr dental implant surface's bioactivity.

3D-bioprinted alginate-based bioink scaffolds with ß-tricalcium phosphate for bone regeneration applications.

Background/purpose: 3D-printed bone tissue engineering is becoming recognized as a key approach in dentistry for creating customized bone regeneration treatments fitting patients bone defects requirements. 3D bioprinting offers an innovative method to fabricate detailed 3D structures, closely emulating the native bone micro-environment and better bone regeneration. This study aimed to develop an 3D-bioprintable scaffold using a combination of alginate and ß-tricalcium phosphate (ß-TCP) with the Cellink® BioX printer, aiming to advance the field of tissue engineering. Materials and methods: The physical and biological properties of the resulting 3D-printed scaffolds were evaluated at 10 %, 12 %, and 15 % alginate combined with 10 % ß-TCP. The scaffolds were characterized through printability, swelling behavior, degradability, and element analysis. The biological assessment included cell viability, alkaline phosphatase (ALP) activity. Results: 10 % alginate/ß-TCP 3D printed at 25 °C scaffold demonstrated the optimal condition for printability, swelling capability, and degradability of cell growth and nutrient diffusion. Addition of ß-TCP particles significantly improved the 3D printed material viscosity over only alginate (P < 0.05). 10 % alginate/ß-TCP enhanced MG-63 cell's proliferation (P < 0.05) and alkaline phosphatase activity (P < 0.001). Conclusion: This study demonstrated in vitro that 10 % alginate/ß-TCP bioink characteristic for fabricating 3D acellular bioprinted scaffolds was the best approach. 10 % alginate/ß-TCP bioink 3D-printed scaffold exhibited superior physical properties and promoted enhanced cell viability and alkaline phosphatase activity, showing great potential for personalized bone regeneration treatments.

Automatic recognition of teeth and periodontal bone loss measurement in digital radiographs using deep-learning artificial intelligence.

Background/purpose: Artificial Intelligence (AI) can optimize treatment approaches in dental healthcare due to its high level of accuracy and wide range of applications. This study seeks to propose a new deep learning (DL) ensemble model based on deep Convolutional Neural Network (CNN) algorithms to predict tooth position, detect shape, detect remaining interproximal bone level, and detect radiographic bone loss (RBL) using periapical and bitewing radiographs. Materials and methods: 270 patients from January 2015 to December 2020, and all images were deidentified without private information for this study. A total of 8000 periapical radiographs with 27,964 teeth were included for our model. AI algorithms utilizing the YOLOv5 model and VIA labeling platform, including VGG-16 and U-Net architecture, were created as a novel ensemble model. Results of AI analysis were compared with clinicians' assessments. Results: DL-trained ensemble model accuracy was approximately 90% for periapical radiographs. Accuracy for tooth position detection was 88.8%, tooth shape detection 86.3%, periodontal bone level detection 92.61% and radiographic bone loss detection 97.0%. AI models were superior to mean accuracy values from 76% to 78% when detection was performed by dentists. Conclusion: The proposed DL-trained ensemble model provides a critical cornerstone for radiographic detection and a valuable adjunct to periodontal diagnosis. High accuracy and reliability indicate model's strong potential to enhance clinical professional performance and build more efficient dental health services.

3D-Printed PLA Scaffold with Fibronectin Enhances In Vitro Osteogenesis.

BACKGROUND: Tricalcium phosphate (TCP, Molecular formula: Ca3(PO4)2) is a hydrophilic bone graft biomaterial extensively used for guided bone regeneration (GBR). However, few studies have investigated 3D-printed polylactic acid (PLA) combined with the osteo-inductive molecule fibronectin (FN) for enhanced osteoblast performance in vitro, and specialized bone defect treatments. AIM: This study evaluated PLA properties and efficacy following glow discharge plasma (GDP) treatment and FN sputtering for fused deposition modeling (FDM) 3D printed PLA alloplastic bone grafts. METHODS: 3D trabecular bone scaffolds (8 × 1 mm) were printed by the 3D printer (XYZ printing, Inc. 3D printer da Vinci Jr. 1.0 3-in-1). After printing PLA scaffolds, additional groups for FN grafting were continually prepared with GDP treatment. Material characterization and biocompatibility evaluations were investigated at 1, 3 and 5 days. RESULTS: SEM images showed the human bone mimicking patterns, and EDS illustrated the increased C and O after fibronectin grafting, XPS and FTIR results together confirmed the presence of FN within PLA material. Degradation increased after 150 days due to FN presence. 3D immunofluorescence at 24 h demonstrated better cell spreading, and MTT assay results showed the highest proliferation with PLA and FN (p < 0.001). Cells cultured on the materials exhibited similar alkaline phosphatase (ALP) production. Relative quantitative polymerase chain reaction (qPCR) at 1 and 5 days revealed a mixed osteoblast gene expression pattern. CONCLUSION: In vitro observations over a period of five days, it was clear that PLA/FN 3D-printed alloplastic bone graft was more favorable for osteogenesis than PLA alone, thereby demonstrating great potential for applications in customized bone regeneration.

Accuracy of implant site preparation in robotic navigated dental implant surgery.

BACKGROUND: Modern technological advancements have led to increase in the development of surgical robots in dentistry, resulting in excellent clinical treatment outcomes. PURPOSE: This study aimed to determine the accuracy of automatic robotic implant site preparation for different implant sizes by correlating planned and posttreatment positions, and to compare the performance of robotic and human freehand drilling. METHOD: Seventy-six drilling sites on partially edentulous models were used, with three different implant sizes (Ø = 3.5 × 10 mm, 4.0 × 10 mm, 5.0 × 10 mm). The robotic procedure was performed using software for calibration and step-by-step drilling processes. After robotic drilling, deviations in the implant position from the planned position were determined. The angulation, depth, and coronal and apical diameters on the sagittal plane of sockets created by human and robotic drilling were measured. RESULTS: The deviation of the robotic system was 3.78° ± 1.97° (angulation), 0.58 ± 0.36 mm (entry point), and 0.99 ± 0.56 mm (apical point). Comparison of implant groups showed the largest deviation from the planned position for 5 mm implants. On the sagittal plane, there were no significant differences between robotic and human surgery except for the 5-mm implant angulation, indicating similar quality between human and robotic drilling. Based on standard implant measurements, robotic drilling exhibited comparable performance to freehand human drilling. CONCLUSIONS: A robotic surgical system can provide the greatest accuracy and reliability regarding the preoperative plan for small implant diameters. In addition, the accuracy of robotic drilling for anterior implant surgery can also be comparable to that of human drilling.

Functionalization of zirconia ceramic with fibronectin proteins enhanced bioactivity and osteogenic response of osteoblast-like cells.

Introduction: To overcome the genuine bioinert properties of zirconia ceramic, functionalization of the surface with the bioactive protein fibronectin was conducted. Methods: Glow discharge plasma (GDP)-Argon was first used to clean the zirconia surface. Then allylamine was treated at three different powers of 50 W, 75 W, and 85 W and immersed into 2 different fibronectin concentrations (5 µg/ml and 10 µg/ml). Results and Discussion: After surface treatment, irregularly folded protein-like substances were attached on the fibronectin coated disks, and a granular pattern was observed for allylamine grafted samples. Infrared spectroscopy detected C-O, N-O, N-H, C-H, and O-H functional groups for fibronectin treated samples. Surface roughness rose and hydrophilicity improved after the surface modification, with MTT assay showing the highest level of cell viability for the A50F10 group. Cell differentiation markers also showed that fibronectin grafted disks with A50F10 and A85F10 were the most active, which in turn encouraged late-stage mineralization activity on 21d. Up-regulation of osteogenic related mRNA expression from 1d to 10d can be observed in RT-qPCR data for ALP, OC, DLX5, SP7, OPG and RANK biomarkers. These physical and biological properties clearly indicate that an allylamine and fibronectin composite grafted surface significantly stimulated the bioactivity of osteoblast-like cells, and can be utilized for future dental implant applications.

Fabrication of Solvent-Free PCL/ß-TCP Composite Fiber for 3D Printing: Physiochemical and Biological Investigation.

Manufacturing three-dimensional (3D) objects with polymers/bioceramic composite materials has been investigated in recent years. In this study, we manufactured and evaluated solvent-free polycaprolactone (PCL) and beta-tricalcium phosphate (ß-TCP) composite fiber as a scaffold material for 3D printing. To investigate the optimal ratio of feedstock material for 3D printing, the physical and biological characteristics of four different ratios of ß-TCP compounds mixed with PCL were investigated. PCL/ß-TCP ratios of 0 wt.%, 10 wt.%, 20 wt.%, and 30 wt.% were fabricated, with PCL melted at 65 °C and blended with ß-TCP with no solvent added during the fabrication process. Electron microscopy revealed an even distribution of ß-TCP in the PCL fibers, while Fourier transform infrared spectroscopy demonstrated that the biomaterial compounds remained intact after the heating and manufacturing process. In addition, adding 20% ß-TCP into the PCL/ß-TCP mixture significantly increased hardness and Young's Modulus by 10% and 26.5%, respectively, suggesting that PCL-20 has better resistance to deformation under load. Cell viability, alkaline phosphatase (ALPase) activity, osteogenic gene expression, and mineralization were also observed to increase according to the amount of ß-TCP added. Cell viability and ALPase activity were 20% higher with PCL-30, while upregulation for osteoblast-related gene expression was better with PCL-20. In conclusion, PCL-20 and PCL-30 fibers fabricated without solvent exhibited excellent mechanical properties, high biocompatibility, and high osteogenic ability, making them promising materials for 3D printing customized bone scaffolds promptly, sustainably, and cost-effectively.

Equation for Tooth Size Prediction from Mixed Dentition Analysis for Taiwanese Population: A Pilot Study.

BACKGROUND: In mixed dentition analysis, estimation of the mesiodistal width of unerupted permanent canines and premolars is essential for successful diagnosis and treatment planning. The present study aimed to develop a simple linear equation to predict permanent tooth sizes from mixed dentition analysis for Taiwanese people. METHODS: The sample comprised 200 dental casts, derived from Taiwanese patients (100 males and 100 females; age, 12-35 years). Mesial distal tooth widths were measured in dental casts with a digital caliper. A student's t-test was conducted to detect tooth size correlations with gender-specific differences, as well as intra-arch counterparts. Standard linear regression was conducted to develop a simple equation representing predictions of canine-premolar relationships. RESULTS: All teeth were not significantly different between the left and right sides, regardless of gender and upper or lower arches. In terms of types of teeth, males had larger tooth dimensions in both arches than females. New regression equations for estimating the dimensions of the unerupted canines and premolars in the Taiwanese population were developed. CONCLUSIONS: Using a sample of Taiwanese people, new models derived for females and males separately were developed, which should provide highly accurate predictions for unerupted canines and premolars in the Taiwanese population.

Application of optical coherence tomography to study the structural features of oral mucosa in biopsy tissues of oral dysplasia and carcinomas.

OBJECTIVE: This study aims to examine the ability of optical coherence tomography (OCT) to differentiate ex vivo epithelial structure of benign disorders, dysplastic, and oral squamous cell carcinoma (OSCC) in comparison with the structure of normal marginal mucosa of oral biopsies. As a secondary objective, we examined the inter- and intra-observer variations of OCT measurements of two calibrated assessors. MATERIALS AND METHODS: Oral biopsies (n = 44) were scanned using the swept source OCT (SSOCT) and grouped by pathology diagnosis to benign, dysplasia or carcinoma. Two trained and calibrated assessors scored on the five OCT variables: thickness of keratin layer (KL), epithelial layer (EL), homogeneity of lamina propria (LP), basement membrane integrity (BMI), and the degree of reflection of the epithelial layer (Ep Re). Chi-square tests and Fischer's exact method were used to compare the data. RESULTS: The OCT images showed breached BM status in all the OSCC samples (100%). Epithelial reflection was noted to be hyper-reflective in all the OSCC and oral dysplasia samples (100%). An increase in KL in 66.67% of the OSCC and 100% of the oral dysplasia samples was found. EL was increased in all the OSCC samples (100%) and 85.72% of the oral dysplasias. Kappa values showed that there was very good agreement (over 0.7) when scoring individual parameters between the two assessors. CONCLUSION: The study showed that the BM status was a key parameter in the detection of SCC and for differentiating SCC from oral dysplasia or benign disorders. CLINICAL RELEVANCE: OCT is a non-invasive and non-radioactive adjunct diagnostic tool that can provide immediate results on the structure of oral mucosa. The BM status measured ex vivo was a key parameter in the detection of SCC and for differentiating SCC from oral dysplasia or benign disorders.

Increasing trends in admissions due to non-communicable diseases over 2012 to 2017: findings from three large cities in Myanmar.

BACKGROUND: Globally, cardiovascular diseases, chronic respiratory diseases, cancers, and diabetes are the four major non-communicable diseases (NCDs) contributing to more than 80% of mortality and morbidity due to NCDs. In Myanmar, the proportional mortality rate due to NCDs increased from 46.9% in 2000 to 68% in 2017. However, the trends and patterns of four major NCDs or their hospital admissions are not known. In this regard, we aimed to assess the trends and profile of admissions with four major NCDs using final diagnosis coded in International Classification of Diseases-2010 version (ICD-10) from medical record data of the large tertiary hospitals in different regions of Myanmar. RESULTS: Of the 774,970 total admissions in the study hospitals, the median and interquartile range (IQR) age was 39 (25-55) years and 51.6% were males. Over a 6-year period, there was not only 2.2-fold increase in the number of admissions due to any of four major NCDs but also their proportion increased significantly from 18.8% in 2012 to 25.4% in 2017 (chi-square for trend, p value < 0.001). The number of admissions due to cancers, cardiovascular diseases, and chronic respiratory diseases also showed linear increasing trends at the rate of 1741 (95% CI 766 to 2715), 1797 (95% CI 345 to 3249), and 597 (95% CI 530 to 612) per year, respectively. Though the admissions with diabetes increased over the years, the rate of increase of 284 (95% CI - 60 to 628) per year was not statistically significant. Among cancer admissions, colorectal (13.1%), breast (13.0%), and lung (11.0%) cancers were the commonest. Stroke (30.6%) and ischemic heart disease (21.9%) admissions were the highest among the cardiovascular diseases. Chronic obstructive pulmonary disease (35.5%) and type 2 diabetes (53.9%) were commonest among chronic respiratory diseases and diabetes, respectively. CONCLUSION: There was a disproportionate increase in NCD admissions which requires tertiary health facilities to increase their infrastructure and trained workforce to cater to such admissions. The primary health care facilities have to be strengthened for prevention, early detection, and efficient management of NCDs to prevent life-threatening complications requiring hospitalization.

A case report of bleeding from a duodenal varix: Rare cause of upper gastrointestinal bleeding.

INTRODUCTION: Ectopic variceal bleeding is uncommon, accounts for 2-5% of variceal bleeding, of which 17% is in duodenum. PRESENTATION OF CASE: 62-year-old lady with newly diagnosed liver cirrhosis on admission, presented with severe upper gastrointestinal bleeding (UGIB), was ultimately diagnosed with bleeding duodenal varices with single-balloon enteroscopy, after multiple oesophagogastroduodenoscopies (OGDs) and CT scans which failed to identify the varices. She was treated successfully with duodenectomy. DISCUSSION: Endoscopy and CT angiography remain the diagnostic modalities of choice. However, diagnosis can be difficult as evidenced by three OGDs and two CTMAs yielding negative findings in this case. Endoscopic diagnosis is challenging and often delayed due to its rarity and unusual location. CONCLUSION: Ectopic variceal bleeding is a rare but important cause of UGIB. Diagnosis is challenging and management of this condition should take a multidisciplinary approach, involving experienced gastroenterologists, interventional radiologists and surgeons. Endoscopic ligation or sclerotherapy is the first-line of treatment.

Revision Procedures After Failed Adjustable Gastric Banding: Comparison of Efficacy and Safety.

BACKGROUND: Laparoscopic adjustable gastric banding (LAGB) was one of the commonly performed bariatric operations; however, it carries a high revision rate. The aim of the present study was to report the long-term outcomes of LAGB and compare the outcomes between the different revision procedures. METHODS: All patients who underwent LAGB in a large bariatric center in Asia between May 2002 and April 2011 were included. Interval between primary LAGB to the revision operation, the reason and type of revision surgery were identified and analyzed. RESULTS: A total of 275 consecutive patients were included. All of the procedures were completed laparoscopically with no major complications. The percentage of excess weight loss (%EWL) at 10-year follow-up was 45%. In this study, 53 patients (19.3%) had revision surgery, including with 26 single anastomosis (mini-) gastric bypass (R-LSAGB) (49%), 17 sleeve gastrectomy (R-LSG) (32.1%), 9 Roux-en-Y gastric bypass (R-LRYGB) (17%), and 1 other procedure (1.9%). A major complication occurred in 6 patients (11.3%). All of the follow-up patients with revision surgeries had %EWL > 50% at the 2-year follow-up. R-LSAGB patients achieved better weight loss than those who underwent R-LSG and R-LRYGB (p = 0.001). CONCLUSIONS: The long-term result for weight loss after LAGB is unsatisfactory. The revision of failed LAGB to other bariatric surgeries is safe and can be performed in one stage with a low complication rate. Patients who underwent R-LSAGB had better weight loss results than the R-LSG or R-LRYGB patients.

Metabolic Surgery for Diabetes Treatment: Sleeve Gastrectomy or Gastric Bypass?

BACKGROUND: Bariatric surgery has gained reputation for its metabolic effect and is increasingly being performed to treat type 2 diabetes mellitus (T2DM). However, there is still a gray area regarding the choice of surgical procedure according to patient characteristics due to inadequate evidences, so far. We aim to compare the efficacy of two most commonly performed bariatric/metabolic surgeries, sleeve gastrectomy (SG) and gastric bypass (GB) with regard to remission of T2DM after surgery. METHODS: Outcomes of 579 (349 female and 230 male) patients who had undergone SG (109) or GB (470) for the treatment of T2DM with 1-year follow-up were assessed. The remission of T2DM after SG or GB surgery was evaluated in matched groups using the ABCD scoring system. The ABCD score is composed of the age, BMI, C-peptide levels and duration of T2DM (years). RESULTS: The weight loss of the SG patient at 1 year after surgery was similar to the GB patients [26.3 (1.1) vs. 32.6 (1.2) %; p = 0.258]. The mean BMI decreased from 35.7 (7.2) to 28.3 (3.7) Kg/m2 in SG patients at 1 year after surgery and decreased from 36.9 (7.2) to 26.7 (4.5) Kg/m2 in the GB patients. The mean HbA1c decreased from 8.8 to 6.1 % of the SG group and from 8.6 to 5.9 % of the GB group. Sixty-one (56.0 %) patients of the SG group and 300 (63.8 %) of the GB group achieved complete remission of T2DM (HbA1c < 6.0 %) at 1 year after surgery without statistical difference. However, GB exhibited significantly better glycemic control than the SG surgery in groups stratified by different ABCD score. At 5 year after surgery, GB had a better remission of T2DM than SG (53.1 vs. 35.3 %; p = 0.055). CONCLUSIONS: In conclusion, although both SG and GB are effective metabolic surgery, GB carries a higher power on T2DM remission than SG. ABCD score is useful in T2DM patient classification and selection for different procedures.

Metabolic Surgery for Type 2 Diabetes Mellitus: Experience from Asia.

Type 2 diabetes mellitus (T2DM) is a current global health priority and Asia is the epicenter of this epidemic disease. Unlike in the west, where older population is most affected, the burden of diabetes in Asian countries is disproportionately high in young to middle-age adults. The incidence of diabetic nephropathy is alarmingly high in patients with early onset T2DM, especially in those with poor glycemic control. How to control this chronic and debilitating disease is currently a very important health issue in Asia. Bariatric surgery has proven successful in treating not just obesity but also T2DM in morbid obese patients (body mass index [BMI] >35 kg/m²). Gastrointestinal metabolic surgery recently has been proposed as a new treatment modality for obesity related T2DM for patients with BMI <35 kg/m². Many studies from Asia reported promising results of metabolic surgery to treat obese patients with T2DM which is not well controlled. It has been demonstrated that changes in gastrointestinal hormone secretion after gastrointestinal surgery would favor an early improvement of T2DM in Asians. New procedures have also been designed and proposed specifically for the treatment of diabetes in Asia. This article examines clinical trial data and accepted algorithms with a view toward elucidating the application of metabolic surgery for the treatment of T2DM in the Asia. We propose a systematic approach to surgical treatment, addressing current evidences, patient selection, procedure of choice, and timing and guideline for new procedures.

Bariatric Surgery for Patients With Early-Onset vs Late-Onset Type 2 Diabetes.

IMPORTANCE: The prevalence of early-onset type 2 diabetes mellitus (T2DM), which responds poorly to medical treatment, is increasing. Bariatric surgery has been well recognized for its effectiveness in the remission of T2DM, but its effectiveness and durability in the remission of early-onset T2DM has not yet been explored. OBJECTIVE: To compare the short- and long-term outcomes of bariatric surgery with a specific focus on the rate of remission of T2DM in patients with early-onset (age <40 years) and late-onset (age ≥40 years) T2DM. DESIGN, SETTING, AND PARTICIPANTS: In this cohort study, 558 Taiwanese patients (339 with early-onset T2DM and 219 with late-onset T2DM) with a body mass index (calculated as weight in kilograms divided by height in meters squared) above 25 underwent bariatric surgery to ameliorate T2DM between January 1, 2007, and December 31, 2013. Patients were followed up for at least 1 year. Preoperative, perioperative, and postoperative clinical and laboratory data were prospectively collected and compared between the 2 groups. MAIN OUTCOMES AND MEASURES: Rate of remission of T2DM (hemoglobin A1C <6.0% without antiglycemic medication) was the primary outcome measure. RESULTS: Of the 558 patients (345 women) in the study, mean (SD) ages were 33.5 (7.5) for those with early-onset T2DM and 50.6 (6.5) with late onset T2DM. Those with early-onset T2DM had higher mean (SD) preoperative BMI and hemoglobin A1C values (39.4 [8.5] and 8.7% [3.8%] of total hemoglobin [to convert hemoglobin to a proportion of total hemoglobin, multiply by 0.01], respectively) than did patients with late-onset T2DM (36.7 [7.5] and 8.2% [1.6%], respectively). Distribution of surgical procedures and major complications were similar between the 2 groups. At 1 year, patients with early-onset T2DM achieved greater weight loss than those with late-onset T2DM, although the difference was not statistically significant. A higher rate of complete remission of T2DM was observed in patients with early-onset T2DM than in those with late-onset disease (193 [56.9%] vs 110 [50.2%]; P = .02). At 5 years, patients with early-onset T2DM still maintained a higher rate of weight loss (mean [SD], 30.4% [11.8%] vs 21.6% [11.7%]; P = .002) and higher rate of remission (47 of 72 [65.3%] vs 26 of 48 [54.2%]; P = .04) than did those with late-onset disease. Age at bariatric surgery, duration of T2DM, and preoperative C-peptide level were independent predictors of remission. The remission rate was directly related to extent of weight loss. Multivariate analysis confirmed the higher rate of remission in the group with early-onset T2DM. CONCLUSIONS AND RELEVANCE: This article describes the largest long-term study examining bariatric surgery for patients with early-onset T2DM. Bariatric surgery may achieve better and more long-lasting glycemic control in select patients with early-onset T2DM than in those with late-onset T2DM.

Orofacial pain of muscular origin is not associated with herpes virus-6 infection: a pilot study.

AIMS: To carry out a pilot study to test the hypothesis that human herpes virus-6 (HHV-6) infection or reactivation plays a role in the pathogenesis of temporomandibular disorders (TMD) of muscular origin (ie, localized myalgia). METHODS: Sixteen patients with localized myalgia participated in this pilot study. Thirty-six healthy individuals served as controls. The participants were examined clinically for the presence of the TMD according to the Research Diagnostic Criteria for TMD, and the salivary levels of HHV-6 were measured by quantitative polymerase chain reaction (qPCR). The Z test, Student t test, and Mann- Whitney U test were used as appropriate. RESULTS: The results demonstrated that 77.8% of healthy individuals were HHV-6 positive, but a significantly lower proportion (43.8%) of the TMD patients with localized myalgia were positive for HHV-6 (P < .05, Fisher exact test). The levels of HHV-6B DNA were lower in the saliva of HHV-6-positive TMD patients with localized myalgia (median: 564 genome/mL; range: 184 to 5,835 genome/mL) than in that of healthy individuals (median: 1,081 genome/mL; range: 193 to 8,807 genome/mL), but the difference was not statistically significant (P > .05, Mann-Whitney U test). CONCLUSION: The results of this pilot study indicate that HHV-6 infection or reactivation does not appear to play a role in the pathogenesis of TMD reflecting a localized myalgia.