Chonnam National University Dental Hospital

Peroxisome proliferator-activator receptor (PPAR) γ is a nuclear hormone receptor that regulates glucose homeostasis, lipid metabolism, and adipocyte function. PPARγ is a target for thiazolidinedione (TZD) class of drugs which are widely used for the treatment of type 2 diabetes. Recently, lobeglitazone was developed as a highly effective TZD with reduced side effects by Chong Kun Dang Pharmaceuticals. To identify the structural determinants for the high potency of lobeglitazone as a PPARγ agonist, we determined the crystal structures of the PPARγ ligand binding domain (LBD) in complex with lobeglitazone and pioglitazone at 1.7 and 1.8 Å resolutions, respectively. Comparison of ligand-bound PPARγ structures revealed that the binding modes of TZDs are well conserved. The TZD head group forms hydrogen bonds with the polar residues in the AF-2 pocket and helix 12, stabilizing the active conformation of the LBD. The unique p-methoxyphenoxy group of lobeglitazone makes additional hydrophobic contacts with the Ω-pocket. Docking analysis using the structures of TZD-bound PPARγ suggested that lobeglitazone displays 12 times higher affinity to PPARγ compared to rosiglitazone and pioglitazone. This structural difference correlates with the enhanced affinity and the low effective dose of lobeglitazone compared to the other TZDs.

BACKGROUND: Periostin is a matricellular protein, and its synthesis in airway epithelial cells and lung fibroblasts is induced by interleukin (IL)-4 and IL-13. The significance of periostin as a biomarker of TH 2-induced airway inflammation, and (importantly) as a measure of the response to TH 2-targeted therapy, has recently been emphasized. We explored the relationship between periostin and airway hyperresponsiveness (AHR) in asthmatic children. METHODS: The study included 83 children aged 6-15 years in an asthmatic group (n = 54) and healthy controls (n = 29). We measured the periostin levels in serum and performed methacholine and mannitol provocation challenges. The responses to mannitol were expressed as the provocative dose causing a 15% fall in the FEV1 (the PD15 dose). RESULTS: Of the 54 subjects with asthma, all had positive methacholine bronchial provocation test (BPT) results and 38 had positive mannitol BPT results. Children with asthma had significantly higher periostin levels than controls [76.0 (65.0-91.8) vs 71.0 (57.5-80.0) ng/mL; P = 0.017]. Periostin levels were significantly correlated with both the methacholine PC20 and mannitol PD15 values. CONCLUSION: Serum levels of periostin, a new biomarker induced by IL-13, were higher in asthmatic children, and were associated with AHR to methacholine and mannitol.

BACKGROUND/PURPOSE: The value of the temporomandibular joint (TMJ) projections of panoramic radiography for diagnosing TMJ osteoarthritis is not completely elucidated. This study aimed to assess the diagnostic accuracy and reliability of panoramic TMJ radiography to detect bony lesions in patients with TMJ osteoarthritis. MATERIALS AND METHODS: This study included 55 TMJs of 44 subjects who were diagnosed with TMJ osteoarthritis. They underwent panoramic radiography (PanRad), lateral (LatTMJ) and frontal (FrnTMJ) projection panoramic TMJ radiography, and cone-beam computed tomography (CBCT). All images were examined by two observers for flattening, erosion, and osteophytes on the condylar head and articular eminence of the TMJ. RESULTS: For detecting flattening lesions on the mandibular condyle, the sensitivities of PanRad, LatTMJ, and FrnTMJ were less than 67% and the combination of LatTMJ and FrnTMJ (ComTMJ) had the highest sensitivity for both observers (67.6% and 79.7%, respectively). For erosion lesions, the sensitivity of ComTMJ for observer 1 was the highest, at 84.3%, whereas the specificity of ComTMJ was the lowest, at 37.5%. The sensitivities of all four methods for observer 2 were less than 54% and the specificities ranged from 75.0% to 100%. The overall diagnostic accuracy was highest for ComTMJ (64.3%), followed by LatTMJ (59.5%). The intraobserver reliability was good for one observer and excellent for the other, and the interobserver reliability was fair or moderate. CONCLUSION: Panoramic TMJ radiography demonstrated limited diagnostic accuracy and acceptable reliability in detecting bony lesions of the TMJ, although it was better than conventional panoramic radiography.

This study evaluated the intraexaminer repeatability of measurements of surface electromyography (EMG) variables and functional indices of the myoelectric signals from the masseter and temporalis muscles bilaterally in 15 healthy men. The test was repeated on two different days without templates. The resting muscle activity was recorded once, and two kinds of maximum voluntary contraction (MVC) tasks were performed and recorded three times. The two MVC tasks involved clenching the teeth and biting down on two cotton rolls bilaterally with the posterior teeth. The intraclass correlation coefficient (ICC) of amplitude was >88% and that of frequency was >95% during the two MVC tasks but not under resting conditions. The ICC of the asymmetry and activity indices during the two MVC tasks was >76%. A Bland-Altman analysis revealed no significant difference in amplitude or frequency or in the two indices between the two days during the MVC tasks. In conclusion, the measurements of surface EMG variables and the indices obtained according to the study protocol were highly repeatable in healthy men. Additional studies using templates and intraexaminer measurement errors are warranted in both men and women for complete validation of these findings.

C16 saturated fatty acid (Palmitic acid) is one of the most common dietary fatty acids which played an important role in the cellular biological functions. Palmitic acid (PA) was tested for potential inhibition of DNA topoisomerase I (topo I) and it exhibited inhibitory activity in the nanomolar range. Treatment of lung adenocarcinoma cell line A549 with PA resulted in a decrease in cell viability in a concentration-dependent manner, and PA showed cytotoxicity with an IC50 value of 150 μM. DNA fragmentation assay and caspase activity indicated that PA does not induce apoptotic cell death in A549 cells. Finally, we found that PA was able to cause an increase in autophagic flux in a time-dependent manner, evidenced by the accumulation of LC3 through monodansylcadaverine (MDC) staining. More importantly, inhibition of autophagy by blocking autophagosome formation via the inhibition of type III Phosphatidylinositol 3-kinases (PI-3K), by 3-Methyladenine (3-MA) was able to effectively suppress PA-induced autophagy. We showed that inhibition of autophagy sensitized the cells signal to PA-induced apoptosis, suggesting the pro-survival function of autophagy induced by PA. Taken together, results from this study reveal that PA as a topo I inhibitor induced autophagic cell death in A549 cells.

The aim of this study was to compare the effects of three cryotherapeutic modalities (ethyl chloride spraying, ice block rubbing and cold gel packing) on facial skin temperature. Thirty healthy volunteers (15 men, 15 women; mean age, 29·4 ± 3·2 years) participated in this study. Each of the three modalities was randomly applied to the skin over the right masseter muscle. The skin surface temperature was recorded at baseline and every 5 min for 60 min after the application of one of the three cryotherapeutic modalities. Immediately after application, cold gel packing demonstrated the greatest reduction in surface temperature (10·6 °C), followed by ethyl chloride spraying (4·3 °C) and ice block rubbing (3·7 °C) (P < 0·001). During the 60-min post-application period, ethyl chloride spraying and ice block rubbing produced similar skin surface temperature changes. The skin surface remained coldest for the longest period of time after cold gel packing. The median time for recovery of the baseline temperature after application of the cold gel pack was about three to four times longer than that for the other modalities (P < 0·001). Ethyl chloride spraying and ice block rubbing resulted in less reduction and faster recovery of skin surface temperature than did cold gel packing. In conclusion, ethyl chloride spraying and ice block rubbing had a limited cooling effect on the facial skin tissue and could not reduce the skin surface temperature enough for local analgesia. Moreover, the cooling effect of cold gel packing was remarkable, but not sufficient for local analgesia.

Abstract Elemental quantification of several single crystalline TEM samples of intermediate thickness range that cannot be quantified by the thin-film approximation method and the ZAF correction were investigated using wedge-shaped samples of known thickness fabricated by the FIB technique. ‘ Thickness factor (T F )’ and ‘ Thickness correction coefficient (T C )’ were proposed as error correction items of ‘ thin-film approximation method ’ to minimize the quantitative error that occurs when quantifying samples of intermediate thickness with TEM-EDS. As the result of T F correction, the quantification error in an Al 2 O 3 TEM sample by TEM-EDS was reduced from about 52.15% to less than 3.28 (± 2.57) % by the correction of only one time. The self-absorption corrected line profiles and self-absorption corrected elemental mapping images in TEM samples of intermediate thickness range were also obtained by T F correction. As an example of application by T F correction, we proposed a novel method measuring thin-film thickness in normal TEM without the EELS system. The T F correction technique is a unique method to overcome the limitation of EDS quantification in the intermediate thickness range. This technique can effectively quantify characteristic x-ray lines less than 1,000 eV in the sample having intermediate thickness ranges using the conventional TEM-EDS system. It is expected to contribute significantly to understanding various characteristics or material nature related to material composition and sample thickness in nanomaterials because it provides more precise quantitative analysis information than current commercial EDS systems.

Purpose: Purpose: Cone beam computed tomography (CBCT) is widely used to evaluate the temporomandibular joint (TMJ).For the three-dimensional (3D) assessment of the TMJ, segmentation of the mandibular condyle and articular fossa is essential.This study aimed to perform deep learning-based 3D segmentation of the mandibular condyle on CBCT images and evaluate the performance of the segmentation.Methods: Methods: CBCT scan data from 99 patients (mean age: 53.319.2years) diagnosed with TMJ disorders were analyzed.From the CBCT images, sagittal, coronal, and axial planes showing the mandibular condyle were selected and combined to form two-dimensional (2D) images.The U-Net deep learning model was used to exclusively segment the mandibular condyle area from the 2D images.From these results, 3D images of the mandibular condyle were reconstructed.Accuracy, precision, recall, and the Dice coefficient were calculated to appraise segmentation performance in each plane. Results: Results:The average Dice coefficient was 0.92 for the coronal and axial planes and 0.82 for the sagittal plane.The CBCT image-based segmentation performance of the mandibular condyle in the coronal and axial planes exceeded that in the sagittal plane.The sharpness and uniformity of the 2D images affected segmentation performance, with segmentation errors more likely occurring in non-uniform images.Certain segmentation errors were corrected through software processing.Finally, the segmented mandibular condyle images were applied to the CBCT data to reconstruct a 3D TMJ model. Conclusions: Conclusions:Mandibular condyle 3D segmentation on CBCT images using U-Net may help evaluate and diagnose TMJ disorders.The proposed segmentation method may assist clinicians in efficiently analyzing CBCT images, particularly in cases involving anatomical abnormalities.

The distribution of patients and practice patterns in pediatric dentistry are constantly changing. This study aimed to analyze the changing trends of patient distribution and treatment patterns in pediatric dentistry.Patient distribution and practice patterns from 2011 to 2020 at the Department of Pediatric Dentistry at Chonnam National University Dental Hospital were collected and reviewed. The total number of outpatients showed a tendency to increase until 2019; however, this value decreased slightly in 2020 owing to the impact of the coronavirus disease pandemic. From 2011 to 2020, the proportion of new patients decreased from 12.18% to 8.98%. In 2011, restorative treatment was the most common, followed by preventive, surgical, endodontic, and orthodontic treatments. After 2012, preventive treatment showed the highest proportion, follwed by restorative, surgical, orthodontic, and endodontic treatments in 2020. The frequency of sedation and the proportion of insured treatments tended to increase over the 10-year study periods.

근막동통은 국소적인 통증과 촉진시 근 압통을 보이면서 근막 발통점이 존재하는 것이 특징인 근육질환이다. 본 증례에서는 야간 이갈이를 호소하는 환자의 임상검사에서 촉진을 통해 측두근 전방 부위의 잠재성 발통점을 확인하였고, 양측의 측두근과 교근에 대해 표면 근전도 검사를 시행한 결과, 이환된 측두근에서 수축 후 근과민성, 이완 지연 및 근피로 가속과 같은 소견을 얻을 수 있었다. 표면근전도 검사는 저작근의 비정상적인 기능을 확인할 수 있으므로 근육성 측두하악장애의 평가에 도움이 될 수 있다. Myofascial pain is a condition associated with regional pain and muscle tenderness characterized by the presence of myofascial trigger points. In this case report, a subject complaining of nighttime bruxism was clinically assessed, and a latent trigger point of the anterior temporalis muscle was identified with manual palpation. A surface electromyographic (SEMG) exam of the anterior temporalis muscle harboring the latent trigger point demonstrated several SEMG features, including post-contraction irritability, delayed relaxation following contraction and accelerated muscle fatigue. It was concluded that a SEMG exam may detect abnormal masticatory muscle function and, therefore, assist in the evaluation of myogenous temporomandibular disorders.

Since botulinum toxin (BoNT) was approved by the US Food and Drug Administration as a prophylactic treatment for chronic migraines in 2010, subsequent studies have shown that BoNT is effective in the management of chronic migraines due to its pain-relieving effects. Therefore, neurologists are increasingly utilizing BoNT as a therapeutic tool for chronic migraine. It is crucial to thoroughly understand the functional anatomy in the head, face, and neck regions to successfully administer BoNT injections in these areas. This review describes the complexity of muscles and their associated target nerves in the frontal, temporal, and occipital areas and serves as a resource for essential functional anatomy, with the goal of providing clinicians with a practical perspective on utilizing BoNT injections.

We present a case report of a 52-year-old male patient who suffered head trauma in a car accident and subsequently experienced taste and smell disorders.Following the accident, the patient reported difficulty detecting salty and sour tastes and diminished olfactory perception.Neurosurgical evaluation revealed subarachnoid and subdural hemorrhages, while otolaryngology investigations revealed hyposmia-a decreased sense of smell.Upon referral to the Department of Oral Medicine, a comprehensive assessment revealed a general bilateral reduction in taste sensation, particularly ageusia for salty taste.Electric taste-detection thresholds significantly exceeded the normal ranges.Integrating our findings from neurosurgery, otolaryngology, and oral medicine resulted in a diagnosis of mixed chemosensory disorder attributed to head trauma.This case highlights the intricate interplay of alterations in taste and smell following head injury, emphasizing the significance of multidisciplinary evaluations in diagnosing mixed chemosensory disorders resulting from traumatic brain injury.

Purpose: Purpose: Coordinated activity between the jaw and neck muscles is important in oral motor tasks such as chewing.This study examined coherence between the jaw and neck muscles during chewing in healthy adults.Methods: Methods: A total of 12 healthy adults underwent electromyography (EMG) of the jaw and neck muscles during right-sided chewing at a frequency of 1 Hz.Surface electrodes were placed over the temporalis (TA), masseter (MS), anterior digastric (DA), and sternocleidomastoid (SM) muscles on the right side.EMG signals were processed for coherence and phase analysis using advanced signal processing techniques. Results: Results:The MS and TA muscle pair exhibited high synchronization when chewing (median coherence=0.992).Contrarily, the coherence values between the MS and DA, as well as the MS and SM muscle pairs, were relatively low (median coherence=0.848and 0.957, respectively).Phase analysis revealed minimal temporal differences between the MS and TA muscle pair and the MS and SM muscle pair, whereas substantial phase shifts were observed between the MS and DA muscle pair.Conclusions: Conclusions: During chewing in healthy adults, the TA muscle works synergistically whereas the DA muscle antagonistically with the MS muscle, and the SM muscle supports the activity of the MS muscle.The observed synchrony and coordination provide insights into the intricate interplay among these muscles during oral motor tasks.

Pleomorphic adenoma is the most common tumor associated with the salivary gland. These tumors are derived from a mixture of ductal and myoepithelial elements and rarely develop in the jawbones. Regardless of the site of origin, pleomorphic adenoma presents as a painless, firm, and slow-growing mass, which is often misdiagnosed as an odontogenic cyst when located in the tooth-bearing areas of the jaws.

Objectives: To investigate transverse treatment outcomes in patients with skeletal Class III malocclusion treated with a surgery-first orthognathic approach (SFA) vs conventional orthognathic surgery (COS). Materials and Methods: This retrospective cohort study included 128 patients, divided into four groups of 32 based on the inclusion of presurgical treatment and extraction of the maxillary premolars: (1) COS with extraction, (2) COS without extraction, (3) SFA with extraction, and (4) SFA without extraction. CBCT scans were taken before and after treatment, with an additional scan after presurgical orthodontic treatment for the COS group only. The primary outcome variable was transverse decompensation, assessed through changes in maxillary and mandibular molar inclination and intermolar width. Predictor variables included treatment approach (SFA vs COS) and extraction status (extraction vs nonextraction). Transverse measurements were compared among the four groups throughout the treatment process. Results: Maxillary molar inclination relative to the occlusal plane increased after treatment, whereas the mandibular molar inclination decreased after treatment, indicating transverse decompensation in the COS and SFA groups, and the extraction and nonextraction groups. There were no statistically significant differences in transverse changes between the COS and SFA groups. Conclusions: Although the difference in transverse decompensation between the COS and SFA groups was not statistically significant, clinicians may still need to consider careful management of transverse decompensation during postsurgical treatment, particularly in SFA cases.

In the case of crown-root fracture due to traumatic injury in anterior tooth and the fracture margin is located subgingivally, forced eruption has been proposed for the reconstruction of deficient bone and soft tissue. Forced eruption is one of the easiest orthodontic approaches that can have an acceptable outcome and prognosis, and has a low incidence of relapse. However, using heavy forces or very fast movements can also cause tissue damage or ankylosis. The following case reports present forced eruption as treatment option of crown fracture in maxillary anterior teeth. (

Purpose: Purpose: The aim of this study was to assess the repeatability of the electrical measurement of taste detection on different dates and in different sessions in healthy young females.Methods: Methods: The sites of electrical stimulation were the tip of the tongue, the posterolateral border of the tongue and the soft palate on the right side unilaterally.The measurements were repeated over three consecutive days, three sessions per day and three times for each session in seventeen healthy females.The repeatability of the measurement was assessed by the intraclass correlation coefficient (ICC).Results: Results: In the dB unit, the ICC of the tip of the tongue and the soft palate was good (61.03 and 66.03, respectively); however, the lateral border of the tongue was a little lower (58.07).In the μA unit, all three test sites had poor ICC.Variability was more significantly associated with the subject factor than with other factors such as trials, sessions and days in dB and μA units.Conclusions: Conclusions: Electrogustometry, which measures electrical taste detection thresholds in the dB unit, is repeatable and acceptable for clinical use in assessing taste function in healthy young females.