Determining the position of the lingula and the mandibular foramen using the antilingula in orthognathic surgery.

BACKGROUND: The antilingula located on the lateral surface of the mandibular ramus has been served as a surgical landmark for the mandibular foramen on the medial surface for decades. However, whether the antilingula truly represents the lingula which is the bony prominence overlapping the mandibular foramen, or the foramen itself, is still unclear. This study thus aimed to examine the position of the antilingula in relation to three reference points: the lingula, the anterior and the posterior borders of the mandibular foramen, as well as to the reference plane used in the inferior alveolar nerve block, and to the posterior border of the mandible. METHODS: This observational study was performed in 113 Thai dry mandibles. The antilingula were identified followed by transferring the reference points to the lateral surface. The distances from the antilingula to the reference points, the reference plane and the posterior border of the ramus were then measured. Chi-square test was calculated for side-dependency of the antilingula. Paired t-test was calculated for difference in measurements in left and right sides. RESULTS: The antilingula could be identified in 92.48% of the mandibles with 86.67 - 90.00% accuracy and 86.67% reliability. There was no significant difference in the presence of the antilingula on left and right sides (p = 0.801). Only 2.5% and 0.83% of the antilingula correspond to the lingula and the anterior border of the mandibular foramen, respectively. However, 85% of the reference points were located within 11 mm radius. The antilingula was found located 2.80 mm inferior to the reference plane and 16.84 mm from the posterior border of the ramus. CONCLUSIONS: The antilingula does not concur with the reference points on the medial surface. Our study also suggests that the safe area for vertical osteotomy is 11 mm posterior to the antilingula or at 30% of the length from the posterior border parallel to the occlusal plane. The use of more accurate techniques in localizing the mandibular foramen combined with the antilingula is more recommended than using the antilingula as a sole surgical guide.

Pre-eruptive intramural resorption in unerupted teeth: a cone-beam computed tomography evaluation of prevalence and related factors.

OBJECTIVE: Pre-eruptive intramural resorption (PEIR) is defined as an abnormal, well-circumscribed radiolucency within the coronal dentin of the tooth, which is often overlooked in plain radiographs. This study aimed to investigate the prevalence of PEIR and its related factors using cone-beam computed tomography (CBCT). METHODS: CBCT images of 590 unerupted teeth were evaluated for the presence of PEIR, location of PEIR, number of lesions in the affected tooth, PEIR score, tooth angulation, tooth position, and pericoronal space. Binary logistic tests were used to analyze the association between the characteristics of PEIR and the patient's demographic data and related factors. RESULTS: The tooth prevalence of PEIR was 13.6% among unerupted teeth. However, it was noteworthy that 19.2% of the unerupted teeth with PEIR were planned to be kept. PEIR was significantly associated with transverse (p = 0.020), inverted-angulated (p = 0.035), and centrally-positioned teeth (p = 0.043). The severity of PEIR was more pronounced in teeth with distal (p = 0.019), lingual (p = 0.023), or inverted-angulated (p = 0.040) positions, and in the absence of pericoronal space (p = 0.036). CONCLUSION: PEIR should be suspected in transverse, inverted-angulated, centrally positioned unerupted teeth, particularly in molars, with no pericoronal space. Further monitoring through CBCT is recommended in such cases. CLINICAL RELEVANCE: The management of unerupted teeth does not always involve surgical removal. Instead, they could be utilized for artificial eruption or tooth transplantation. The present study emphasizes the significance of early detection of PEIR. Clinical recommendations for screening PEIR in unerupted teeth are also proposed, which can be applied to routine plain radiographs.

Establishing Clinically Acceptable PES/WES Threshold for Single- Tooth Implant Restoration.

PURPOSE: Determining the esthetic success of single-tooth implant restorations (STIR) requires an objective tool such as one devised by Belser et al., 2009 - pink esthetic scores and white esthetic scores (PES/WES). This study aimed to utilized PES/WES to establish threshold scores based on (1) detectability and (2) acceptability of a STIR by lay person perception, (3) to study the difference in the ability of laypeople and dentists in detecting the presence of STIR, and (4) to study the pink and white deficiencies in relation to the detectability of the presence of STIR. MATERIALS AND METHODS: A total of 38 calibrated photographs of STIR in the anterior region were scored with PES/WES by 3 prosthodontists. Next, 100 laypeople and 60 dentists were instructed to identify the STIR among the anterior teeth and provide reasoning behind the identification (based on pink and white esthetic criteria). The acceptance of the STIR was recorded. Receiver Operating Characteristics (ROC) analysis was utilized to determine the threshold scores. RESULTS: At the PES/WES score of 17, 71% of laypeople could not correctly identify the STIR, and at the PES/WES score of 12, 80% of laypeople accepted the implant. Out of 3,800 occasions, laypeople correctly identified the STIR 1,770 (46.58%) of those occasions. Among the correctly identified STIR, 751 (42.43%) of those occasions were identified with pink deficiencies and 1019 (57.57%) of those occasions were with white deficiencies. Out of 2,280 occasions, dentists correctly identified STIR 1869 (81.98%) of those occasions. CONCLUSIONS: The PES/WES score of 12 indicates the clinically acceptable threshold, while the score of 17 indicates the detectable threshold for an exceptional esthetic outcome. Laypeople tend to accept the implant despite its detectability. For both laypeople and dentists, root convexity/soft tissue color and texture are the most focused criteria of PES/WES, followed by overall white deficiencies that remain influential. Compared to laypeople, dentists tend to have a higher ability to detect STIR.

Standardized Centella asiatica extract ECa 233 alleviates pain hypersensitivity by modulating P2X3 in trigeminal neuropathic pain.

OBJECTIVE: During oral surgery and temporomandibular joint repositioning, pain hypersensitivity often occurs due to irritation or inflammation of the nerve endings in the orofacial region. This study aimed to investigate the effects of ECa 233, a Centella asiatica-standardized extract, on the development of mechanical hyperalgesia and allodynia induced by chronic constriction injury of the infraorbital nerve in mice. METHODOLOGY: The right infraorbital nerves of the mice were ligated. Oral carbamazepine (20 mg/kg) or ECa 233 (30, 100, or 300 mg/kg) was administered daily for 21 days. Von Frey and air-puff tests were performed on both sides of the whisker pad on days 0, 7, 14, and 21. Thereafter, the expression of purinergic receptor subtype 3 (P2X3) and voltage-gated sodium channel 1.7 (NaV1.7), a transmembrane protein, in the trigeminal ganglion and c-fos immunoreactivity-positive neurons in the trigeminal nucleus caudalis was assessed. RESULTS: After 21 days of infraorbital nerve ligation, the mice showed allodynia- and hyperalgesia-like behavior, P2X3 and NaV1.7 were upregulated in the trigeminal ganglion, and nociceptive activity increased in the trigeminal nucleus caudalis. However, the oral administration of carbamazepine (20 mg/kg), ECa 233 (100 mg/kg), or ECa 233 (300 mg/kg) mitigated these effects. Nevertheless, ECa 233 failed to affect NaV1.7 protein expression. CONCLUSION: Carbamazepine and ECa 233 can prevent pain hypersensitivity in mice. Considering the side effects of the long-term use of carbamazepine, ECa 233 monotherapy or combined ECa 233 and carbamazepine therapy can be used as an alternative for regulating the development of hypersensitivity in trigeminal pain. However, further detailed clinical studies should be conducted to provide comprehensive information on the use of ECa 233.

Standardized Centella asiatica extract ECa 233 alleviates pain hypersensitivity by modulating P2X3 in trigeminal neuropathic pain

Abstract During oral surgery and temporomandibular joint repositioning, pain hypersensitivity often occurs due to irritation or inflammation of the nerve endings in the orofacial region. Objective: This study aimed to investigate the effects of ECa 233, a Centella asiatica-standardized extract, on the development of mechanical hyperalgesia and allodynia induced by chronic constriction injury of the infraorbital nerve in mice. Methodology: The right infraorbital nerves of the mice were ligated. Oral carbamazepine (20 mg/kg) or ECa 233 (30, 100, or 300 mg/kg) was administered daily for 21 days. Von Frey and air-puff tests were performed on both sides of the whisker pad on days 0, 7, 14, and 21. Thereafter, the expression of purinergic receptor subtype 3 (P2X3) and voltage-gated sodium channel 1.7 (NaV1.7), a transmembrane protein, in the trigeminal ganglion and c-fos immunoreactivity-positive neurons in the trigeminal nucleus caudalis was assessed. Results: After 21 days of infraorbital nerve ligation, the mice showed allodynia- and hyperalgesia-like behavior, P2X3 and NaV1.7 were upregulated in the trigeminal ganglion, and nociceptive activity increased in the trigeminal nucleus caudalis. However, the oral administration of carbamazepine (20 mg/kg), ECa 233 (100 mg/kg), or ECa 233 (300 mg/kg) mitigated these effects. Nevertheless, ECa 233 failed to affect NaV1.7 protein expression. Conclusion: Carbamazepine and ECa 233 can prevent pain hypersensitivity in mice. Considering the side effects of the long-term use of carbamazepine, ECa 233 monotherapy or combined ECa 233 and carbamazepine therapy can be used as an alternative for regulating the development of hypersensitivity in trigeminal pain. However, further detailed clinical studies should be conducted to provide comprehensive information on the use of ECa 233.

Two-dimensional facial measurements for anterior tooth selection in complete denture treatment.

Purpose: Anterior tooth selection is one of the most challenging parts in determining tooth dimensions and critical to the aesthetic aspect of the complete denture treatment. However, the methods for anterior tooth size selection using facial measurements are still controversial. This study aimed to investigate the relationship between dental measurements and facial measurements, and to establish the anterior tooth size prediction equation using facial dimensions in the Thai population for the complete denture treatment. Materials & methods: One hundred and twenty-five Thai participants (53 men and 72 women) aged 18-35 years old with Angle class I occlusion, did not currently undergo orthodontic treatment, had normal alignment on the maxillary anterior teeth, no attrition, abrasion, proximal restoration or prosthesis were investigated. One frontal facial photograph and one dental photograph of each participant were made using an image analyzing program (ImageJ version 1.53b) to measure the six horizontal facial distances, five vertical facial distances and three dental distances as 2D facial and dental measurements. Pearson correlation and multiple linear regression analysis were performed. Results: The difference of facial and dental measurements between men and women were statistically significant (P < .001). Interpupillary width, interlateral canthal width, intercommissural width and bizygomatic width were correlated to dental measurements in both sexes. Intermedial canthal width and lip thickness were correlated to dental measurements in women. Face length and lateral canthus to lower border of face were correlated to dental measurements in men. Prediction equations of each dental measurement were established using only horizontal facial dimension and using both horizontal and vertical facial dimensions. Conclusions: Facial and dental dimensions are sex-dependent. Facial measurements can be applied in a regression equation to predict dental measurements. Adding vertical dimensions of facial measurements to the prediction equations of anterior tooth size selection results in a higher R squared to 0.444. This finding can be used as a tool for anterior tooth size selection in the complete denture treatment.

Differential expression of PEA3 in odontogenic cysts and tumors.

BACKGROUND: PEA3 transcription factor has been identified as a downstream target of the MAPK and PI3K pathways, and PEA3 overexpression has been observed in a variety of tumor types. We aimed to evaluate PEA3 expression in odontogenic cysts and tumors and compare the expression among odontogenic lesions. In addition, the correlations between PEA3 expression and clinicopathological characteristics of conventional ameloblastoma and unicystic ameloblastoma were investigated. METHODS: This study was performed on 165 samples of odontogenic cysts and tumors including 20 dentigerous cysts, 20 odontogenic keratocysts, 16 adenomatoid odontogenic tumors, 5 ameloblastic fibromas, 45 unicystic ameloblastomas, and 59 conventional ameloblastomas. The sections were immunohistochemically stained with mouse monoclonal anti-PEA3 antibody and PEA3 expression was evaluated as the immunoreactive score. RESULTS: PEA3 expression was absent in all dentigerous cysts (DCs) and odontogenic keratocysts, while all adenomatoid odontogenic tumors showed either no (75%) or low (25%) expression of PEA3. Most of the ameloblastic fibromas (60%) displayed no PEA3 expression. A high expression of PEA3 was observed in a substantial number of unicystic ameloblastomas (48.9%) and conventional ameloblastomas (49.2%) in our study. PEA3 expression in DCs, odontogenic keratocysts and adenomatoid odontogenic tumors were significantly different from that in conventional ameloblastomas and that in unicystic ameloblastomas (p < 0.05). The expression of PEA3 was significantly different in the age groups of unicystic ameloblastomas and histological subtypes of conventional ameloblastomas (p < 0.05). CONCLUSION: PEA3 overexpression is predominant in unicystic ameloblastomas and conventional ameloblastomas compared to other odontogenic lesions, indicating a pivotal role of PEA3 as a downstream effector of MAPK pathway in these two odontogenic lesions.

Stem cell-derived exosomes from human exfoliated deciduous teeth promote angiogenesis in hyperglycemic-induced human umbilical vein endothelial cells.

OBJECTIVE: To investigate the angiogenesis in human umbilical vein endothelial cells (HUVEC) under high glucose concentration, treated with exosomes derived from stem cells from human exfoliated deciduous teeth (SHED). METHODOLOGY: SHED-derived exosomes were isolated by differential centrifugation and were characterized by nanoparticle tracking analysis, transmission electron microscopy, and flow cytometric assays. We conducted in vitro experiments to examine the angiogenesis in HUVEC under high glucose concentration. Cell Counting Kit-8, migration assay, tube formation assay, quantitative real-time PCR, and immunostaining were performed to study the role of SHED-derived exosomes in cell proliferation, migration, and angiogenic activities. RESULTS: The characterization confirmed SHED-derived exosomes: size ranged from 60-150 nm with a mode of 134 nm, cup-shaped morphology, and stained positively for CD9, CD63, and CD81. SHED-exosome significantly enhanced the proliferation and migration of high glucose-treated HUVEC. A significant reduction was observed in tube formation and a weak CD31 staining compared to the untreated-hyperglycemic-induced group. Interestingly, exosome treatment improved tube formation qualitatively and demonstrated a significant increase in tube formation in the covered area, total branching points, total tube length, and total loop parameters. Moreover, SHED-exosome upregulates angiogenesis-related factors, including the GATA2 gene and CD31 protein. CONCLUSIONS: Our data suggest that the use of SHED-derived exosomes potentially increases angiogenesis in HUVEC under hyperglycemic conditions, which includes increased cell proliferation, migration, tubular structures formation, GATA2 gene, and CD31 protein expression. SHED-exosome usage may provide a new treatment strategy for periodontal patients with diabetes mellitus.

An educational board game for learning orofacial spaces: An experimental study comparing collaborative and competitive approaches.

Odontogenic orofacial space infection is an important topic in the dental curriculum. However, dental students do encounter difficulties in identifying the patterns of odontogenic infection spreading through fascial spaces. The implementation of game concepts might allow them to actively learn this topic by engagement. This research aimed to develop a game for learning about the orofacial spaces and to evaluate its implementation whether a competitive or collaborative approach would be more effective for dental undergraduates. 'Trace the Spread' has been developed as a table-top board game, consisting of a main board presenting the anatomical map of a human model and two types of cards (quest and action cards). Eight groups of four students were randomly assigned into either the collaboration or competition group. The students were given pre- and post-knowledge assessments to evaluate knowledge improvement after game completion, where they were asked to rate their satisfaction toward the game using a paper-based questionnaire. The findings demonstrated a significant increase in the knowledge assessment scores after game completion in both collaboration (p < 0.001) and competition groups (p = 0.003). The score improvement of the collaboration group was significantly higher than that of the competition group (p < 0.001). The students tended to show satisfaction with the game, in which the collaboration group rated the game more positively compared to the competitive approach. This game appeared to be effective for learning orofacial space infections, and the learning environment within the collaborative group was found to be more supportive in terms of knowledge improvement and satisfaction.

Understanding the mandibular condyle morphology on panoramic images: A cone beam computed tomography comparison study.

OBJECTIVE: To compare variations in condylar morphology (CM) in panoramic images with those demonstrated in cone beam computed tomography (CBCT) and to investigate factors related to the variations. METHODS: Three thousand panoramic images were analyzed for CM classification and relationship between CM and patient factors. Then, CM of 178 cases of panoramic and CBCT images were compared. RESULTS: CM was classified into five types: round (70.63%), pointed (15.12%), angled (8.43%), flat (4.53%), and irregular (1.28%). CM was significantly related to all patient factors (p < 0.001). Round CM in panoramic images presented as round in CBCT images. Pointed and flat CM were observed mainly in the lateral aspect of the condyle, and no angle-shaped CM was found, according to CBCT images. CONCLUSION: Round, flat, and pointed CM seen on panoramic images possibly reflected the actual shape of the condyle, as confirmed by CBCT, whereas angled CM appeared not to exist.

Qualitative Histological Evaluation of Various Decalcifying Agents on Human Dental Tissue.

OBJECTIVE: Dental hard tissue is among the hardest tissue of humans because it contains high amounts of inorganic substances. This leads to difficulty in preparing histological sections for histopathological examination. Acid and chelating agents are generally used to decalcify teeth. We aimed to compare the histological quality of teeth decalcified with various calcifying agents including 5% nitric acid, 50% formic acid with 20% sodium citrate (Anna Morse solution), 10% formic acid, commercial solution, and 14.4% neutral EDTA. MATERIALS AND METHODS: Freshly extracted premolar teeth were fixed and submitted for decalcification using different agents. Histological examination was qualitatively evaluated for tissue integrity and staining quality. RESULTS: Dentin integrity of teeth decalcified with all decalcifying agents did not show any statistical differences except that with the formic acid, whereas cementum integrity decalcified with neutral EDTA showed a superior score compared with other agents. Tissue integrity and staining quality of dental pulp cells were the best decalcified with neutral EDTA or Anna Morse solution. CONCLUSION: Our findings demonstrated that EDTA and Anna Morse solution gave a similar efficiency in the preservation of tissue integrity while Anna Morse solution may be recommended as a decalcification agent in routine use due to the more satisfying decalcification time than EDTA.

Stem cell-derived exosomes from human exfoliated deciduous teeth promote angiogenesis in hyperglycemic-induced human umbilical vein endothelial cells

Abstract Objective To investigate the angiogenesis in human umbilical vein endothelial cells (HUVEC) under high glucose concentration, treated with exosomes derived from stem cells from human exfoliated deciduous teeth (SHED). Methodology SHED-derived exosomes were isolated by differential centrifugation and were characterized by nanoparticle tracking analysis, transmission electron microscopy, and flow cytometric assays. We conducted in vitro experiments to examine the angiogenesis in HUVEC under high glucose concentration. Cell Counting Kit-8, migration assay, tube formation assay, quantitative real-time PCR, and immunostaining were performed to study the role of SHED-derived exosomes in cell proliferation, migration, and angiogenic activities. Results The characterization confirmed SHED-derived exosomes: size ranged from 60-150 nm with a mode of 134 nm, cup-shaped morphology, and stained positively for CD9, CD63, and CD81. SHED-exosome significantly enhanced the proliferation and migration of high glucose-treated HUVEC. A significant reduction was observed in tube formation and a weak CD31 staining compared to the untreated-hyperglycemic-induced group. Interestingly, exosome treatment improved tube formation qualitatively and demonstrated a significant increase in tube formation in the covered area, total branching points, total tube length, and total loop parameters. Moreover, SHED-exosome upregulates angiogenesis-related factors, including the GATA2 gene and CD31 protein. Conclusions Our data suggest that the use of SHED-derived exosomes potentially increases angiogenesis in HUVEC under hyperglycemic conditions, which includes increased cell proliferation, migration, tubular structures formation, GATA2 gene, and CD31 protein expression. SHED-exosome usage may provide a new treatment strategy for periodontal patients with diabetes mellitus.

Efficacy and mechanism of the antinociceptive effects of cannabidiol on acute orofacial nociception induced by Complete Freund's Adjuvant in male Mus musculus mice.

OBJECTIVES: The objectives were to investigate the efficacy and mechanisms of cannabidiol on orofacial nociception induced by Complete Freund's Adjuvant (CFA) in male Mus musculus mice. DESIGN: For the study of efficacy, mice were divided into seven groups: sham; inflammation; and cannabidiol 0.5, 1, 3, 5, and 10 mg. For the study of mechanisms of cannabidiol, mice were divided into six groups: sham, inflammation, calcitonin gene-related peptide (CGRP) antagonist with and without cannabidiol, and vanilloid receptor 1 antagonist with and without cannabidiol. Spontaneous pain-like behaviors, trigeminal nociception, and trigeminal modulating activity were investigated. RESULTS: CFA injected in the right masseter muscle significantly induced spontaneous pain-like behaviors and the trigeminal nociceptive pathway. This effect was inhibited by injection of 1, 3, 5, and 10 mg of cannabidiol. The 50 % inhibitory concentration of cannabidiol on antinociception was found to be 3 mg/kg. In addition, there was no difference in spontaneous pain-like behaviors with vanilloid receptor 1 antagonist injected before treatment with cannabidiol compared to saline control. Reduced c-fos expression was observed in the trigeminal nucleus caudalis and periaqueductal gray in the group injected with CGRP antagonist before treatment with cannabidiol. CONCLUSION: The antinociceptive effects of cannabidiol induced by acute orofacial nociception is mediated by vanilloid receptor 1 but not by CGRP. Cannabidiol can act with peripheral nonpeptidergic neurons and can be used as an alternative drug or as a synergistic medication in pain treatment.

Polarized Microscopic Analysis of Picrosirius Red Stained Salivary Gland Pathologies: An Observational Study.

OBJECTIVE: Salivary gland diseases and their pathologies may affect the glandular structure including collagen, a major stromal component, in response to tissue damage or diseases. This study aimed to examine the changes in collagens in different salivary gland diseases using polarized picrosirius red staining. MATERIALS AND METHODS: The submandibular gland samples diagnosed as sialadenitis, chronic sclerosing sialadenitis, pleomorphic adenoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma were stained with picrosirius red, Masson's trichrome, and anticollagen I staining. The quantity of collagens was examined and reported as a percentage of positive picrosirius red area. The maturity of collagens was studied with polarized light microscope and reported as a percentage of orange-red and yellow-green polarized collagens, representing the mature and immature collagens, respectively. STATISTICAL ANALYSIS: The % positive areas for picrosirius red representing the collagen amount among salivary gland diseases were analyzed by one-way analysis of variance with Tukey's test. The % orange-red and % yellow-green polarized areas representing the collagen maturity were analyzed by Kruskal-Wallis test and Mann-Whitney U test. RESULTS: The malignant tumors, adenoid cystic carcinoma (29.92) and mucoepidermoid carcinoma (26.59), had higher significant percentage of positive picrosirius red area, compared with the benign tumor (14.56), chronic sclerosing sialadenitis (10.61), and sialadenitis (7.22) (p < 0.05). The percentages of orange-red polarized areas are 48.07, 39.6, 62.67, 83.75, and 76.05 in sialadenitis, chronic sclerosing sialadenitis, pleomorphic adenoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma, respectively. This percentage tended to increase in the benign and malignant lesions with statistical difference, compared with the inflammatory lesions (p < 0.05). There was no statistical difference in the percentages of yellow-green polarized areas among various salivary gland diseases. In addition, the results of Masson's trichrome and anticollagen I staining are corresponding to that of picrosirius red among various salivary gland diseases. CONCLUSIONS: Polarized picrosirius red demonstrated the most amounts of collagen in the malignant lesion, and represented the different maturity of collagens in each lesion group. Studying the amounts and maturity of collagen with picrosirius red for extracellular matrix alteration in salivary gland diseases along with routine hematoxylin and eosin, Masson's trichrome, and immunohistochemistry may provide a better understanding in different salivary gland pathologies.

Anatomical Variations of the Anterior Belly of the Digastric Muscle in Thai Cadavers: A Cross-Sectional Study.

Aim: Because the digastric muscle is considered as an anatomical landmark, its variations may emphasize clinicians to be cautious during surgery. However, previous studies from different ethnicities reported a wide range of occurrence and several types of this muscle variation, pointing the necessity of the data from local population to better treatment decisions. Thus, this study aimed to explore the variations of the anterior belly of the digastric muscle in Thai cadavers. Materials and Methods: This cross-sectional study investigated the submental region of 91 cadavers by convenient sampling method. The characteristics of the variation in the anterior belly were recorded in accordance with sex and side of the cadavers. Multiple logistic regression was calculated for determining the association of occurrence of muscle variation with sexes and sides (α = 0.05). Results: Among 91 cadavers, the accessory bundles were observed in 16 cadavers (10 males and 6 females). The presence of the additional belly was sex and side independent. Three variation types were observed; the arrowhead type and the double-headed type have been previously reported, whereas the asymmetrical fan-shaped type is the new variant that has never been described before. Conclusions: The variation of the anterior belly of the digastric muscle including the new variant can be seen in Thais with low occurrence. To our knowledge, the present study is the first report of the aberrations of the digastric muscle in the Southeast Asian population. Therefore, our study provides the basis for anatomical study of muscular variants and helps surgeons plan the operation to prevent iatrogenic injuries.

Association of HPV and EBV in Oral Verrucous Squamous Cell Carcinoma and Oral Verrucous Hyperplasia.

OBJECTIVE: Oral verrucous squamous cell carcinoma or oral verrucous carcinoma (OVC) is a rare verrucous variant of oral squamous cell carcinoma (OSCC), which accounts for 2 to 12% of all oral carcinomas. Oral verrucous hyperplasia (OVH) is clinically similar to OVC and has been proposed to be a precursor lesion of OVC. Etiopathogenesis of both lesions is still inconspicuous. Oncogenic viruses such as human papillomavirus (HPV) and Epstein-Barr virus (EBV) have been reported to be associated with some cases of OSCC, and we hypothesized that it may act as a causative agent of these verrucous lesions. This study aimed to investigate frequency of HPV and EBV infections in OVC and OVH. MATERIAL AND METHODS: Using polymerase chain reaction (PCR), a total of 35 formalin-fixed paraffin-embedded (FFPE) tissue samples, including 27 OVC samples and 8 OVH samples, were investigated for HPV and EBV infection. HeLa and B95-8 cell lines were used as positive controls of HPV and EBV PCR, respectively. RESULTS: All OVC and OVH samples show a positivity to GAPDH, whereas neither HPV nor EBV PCR products was detected in both OVC and OVH samples. CONCLUSIONS: In summary, our study demonstrated that HPV and EBV are not involved in pathogenesis of OVC and OVH. Other etiologic factors contributing to OVC and OVH need to be further clarified.

Determining of canine position by multiple facial landmarks to achieve natural esthetics in complete denture treatment.

STATEMENT OF PROBLEM: Anterior tooth selection is an important step in complete denture treatment as it plays a pivotal role not only in esthetics but also in mastication and pronunciation. However, conventional methods for tooth selection are not well established and rely on facial measurements and proportions, which vary among different ethnicities. PURPOSE: The purpose of this clinical study was to investigate the relationship between interalar width and intercanine distance and to compare different clinical methods for determining the position of the canine tooth. MATERIAL AND METHODS: Two hundred Thai participants (100 men and 100 women) aged 18 to 25 years with 6 full maxillary anterior teeth were enrolled in this study. The interalar width and intercanine distance were measured with digital vernier calipers and compared by using the paired-samples t test. To determine the canine position, 2 reference lines-the alar line (A line) and the inner canthus of the eye to alar line (IA line)-were drawn through the canine on both sides. The horizontal distances from each reference line to the canine cusp tip and distal contact point were evaluated and then analyzed using the 1-sample t test. RESULTS: All measurements were significantly different between men and women (P<.01). Interalar width was greater than intercanine distance in both sexes. In men, the A line coincided with the canine distal contact point (P>.05). In contrast, the IA line was distal to the canine distal contact point by 3.5 ±3.6 mm on the left side and by 3.9 ±3.4 mm on the right side. In women, the A line was situated between the canine cusp tip and distal contact point. It was mesial to the distal contact point by 2.0 ±2.0 mm on the left side and by 1.8 ±2.0 mm on the right side. The IA line was distal to the canine distal contact point by 1.2 ±2.6 mm on the left side and by 1.6 ±2.7 mm on the right side. CONCLUSIONS: The interalar width is greater than the intercanine distance in both sexes. The A line is more clinically relevant than the IA line for predicting canine position. The A line can directly determine the distal contact point of the canine in edentulous male patients. However, in women, a distance of approximately 2 mm should be added distal to the A line to locate the distal contact point of the canine on both sides.

Online Professionalism of Facebook Usage in Dental Education: A Retrospective Exploration.

AIMS: Unprofessionalism in the use of Facebook has been found among healthcare professionals including dental students. The improper content may be shared to the public, negatively impacting their professions. This study explored account privacy and professionalism on Facebook usage in conjunction with evaluating whether there were correlations among presence of clinical experience, account privacy, and professionalism. MATERIALS AND METHODS: This study retrospectively explored professionalism in the use of Facebook among Mahidol dental undergraduates in the academic year 2019. The students who had identifiable Facebook and accepted a friend request were included into this study. The content on both "About" and "Wall" sections was examined and analyzed using descriptive statistics and χ2 test. RESULTS: Facebook profiles of 522 students were identified. There were 382 (73.18%) students who accepted the friend requests, revealing account privacy: 32 (8.38%) private, 200 (52.36%) limited, and 150 (39.27%) public profiles. Clearly unprofessional content was mostly relevant to sharing information of patients (15.97%), followed by parody content of patients (8.9%). Questionably unprofessional misconducts included political discriminations (14.66%), profanity (3.14%), and alcohol consumption (2.88%). Professionalism was found to be significantly correlated with privacy (p<0.001) and clinical experience (p<0.001). CONCLUSION: Unprofessionalism tended to be higher in clinical years, so professionalism should be emphasized constantly throughout the dental program, especially before starting clinical practice. Privacy concerns should also be suggested for students at the beginning of the program.

Optimal culture conditions for neurosphere formation and neuronal differentiation from human dental pulp stem cells.

OBJECTIVES: Human dental pulp stem cells (DPSCs) have been used to regenerate damaged nervous tissues. However, the methods of committing DPSCs into neural stem/progenitor cells (NSPCs) or neurospheres are highly diverse, resulting in many neuronal differentiation outcomes. This study aims to validate an optimal protocol for inducing DPSCs into neurospheres and neurons. METHODOLOGY: After isolation and characterization of mesenchymal stem cell identity, DPSCs were cultured in a NSPC induction medium and culture vessels. The durations of the culture, dissociation methods, and passage numbers of DPSCs were varied. RESULTS: Neurosphere formation requires a special surface that inhibits cell attachment. Five-days was the most appropriate duration for generating proliferative neurospheres and they strongly expressed Nestin, an NSPC marker. Neurosphere reformation after being dissociated by the Accutase enzyme was significantly higher than other methods. Passage number of DPSCs did not affect neurosphere formation, but did influence neuronal differentiation. We found that the cells expressing a neuronal marker, ß-tubulin III, and exhibiting neuronal morphology were significantly higher in the early passage of the DPSCs. CONCLUSION: These results suggest a guideline to obtain a high efficiency of neurospheres and neuronal differentiation from DPSCs for further study and neurodegeneration therapeutics.

A standardized extract of Centella asiatica (ECa 233) prevents temporomandibular joint osteoarthritis by modulating the expression of local inflammatory mediators in mice.

OBJECTIVES: To investigate the effect of a standardized extract of Centella asiatica (ECa 233), which has anti-inflammatory properties, on the local expression of the transient receptor potential vanilloid 1 (TRPV1), the acid-sensing ion channel subunit 3 (ASIC3), and the calcitonin gene-related peptide (CGRP) in the temporomandibular joint (TMJ) structure 21 days after injecting the TMJ with complete Freund's adjuvant (CFA). METHODOLOGY: A mouse model was induced by analyzing the CFA-injected TMJ on days 7, 14, and 21. We assessed TMJ histology by the osteoarthritis cartilage grade score. Then, we observed the effect of different ECa 233 concentrations (30, 100, and 300 mg/kg) and of 140 mg/kg ibuprofen doses on TRPV1, ASIC3, and CGRP local expression on day 21. RESULTS: Osteoarthritis cartilage scores were 1.17±0.37 and 3.83±0.68 on days 14 and 21, respectively, in the CFA group (n=5). On day 21, TRPV1, ASIC3, and CGRP expression significantly increased in the CFA group. In the ibuprofen-treated group, TRPV1 expression significantly decreased, but ASIC3 and CGRP showed no significant difference. All ECa 233 doses reduced TRPV1 expression, but the 100 mg/kg ECa 233 dose significantly decreased ASIC3 expression. CONCLUSIONS: TRPV1, ASIC3, and CGRP expression increased in mice with TMJ-OA on day 21. All ECa 233 and ibuprofen doses inhibited pathogenesis by modulating the local expression of TRPV1 and ASIC3. Therefore, ECa 233 was more effective than ibuprofen.