Publications by authors named "Keskanya Subbalekha"

28 Publications

  • Page 1 of 1

An approach to a repeated self-biting tongue injury in a toddler.

Arch Pediatr 2021 Sep 8. Epub 2021 Sep 8.

Department of Oral and Maxillofacial Surgery, University Hospital of Giessen and Marburg UKGM GmbH, Campus Marburg, Faculty of Medicine, Philipps University, Marburg 35043, Germany.

Background: Children with tongue injuries often visit the pediatric emergency department. The vast majority of cases can be conservatively treated, while some injuries require operative repair. The aim of this article was to demonstrate a "back-to-basics" approach to a refractory bifid tongue injury in a toddler.

Case Description: A 1-year-old toddler with a tongue injury was unsuccessfully treated three times within a week by a surgeon in another specialty; all reconstructions were mucosal only. The case was then referred to our maxillofacial unit for proper management. On examination, the recurrent injury seemed to occur because of the patient's self-biting habit. We performed the fourth reconstruction of the tongue muscles and mucosa, and because of no dental prosthetic laboratory available in our hospital, we used transparent adhesive drapes fixed by resorbable sutures to cover the patient's anterior teeth instead of bite guards. The toddler was fed via a nasogastric tube for 1 week under 2-day antibiotic prophylaxis and routine oral care. The patient was discharged without any complications 1 week later.

Conclusions And Practical Implications: The causes of repeated orofacial injuries should be identified and require particular attention to establish a proper treatment. For intraoral injuries in pediatric patients, self-biting habits should not be overlooked. The application of materials in an operating theater can help the treating clinicians improve the treatment outcomes.
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http://dx.doi.org/10.1016/j.arcped.2021.08.006DOI Listing
September 2021

Comparing pre- and post-treatment patients' perceptions on dental implant therapy.

Clin Implant Dent Relat Res 2021 Aug 3. Epub 2021 Aug 3.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Background: Appropriate patients' perceptions as one of Patient Reported Outcome Measures (PROMs), are shown to be critical for the sustainable success of implant therapy, little is known however of how they prospectively evolve throughout the treatment process.

Objective: This study aimed to prospectively assess patients' perceptions before and after treatment with dental implants and to identify the impact of patients' characteristics on their perceptions.

Materials And Methods: Patients' perceptions on implant therapy were prospectively assessed by means of purpose-made questionnaire, rating the extent of agreement/disagreement with a set of statements on a visual analog scale. The questionnaire was collected before initial consultation with the implant dentist and post-treatment at least 1 month after prosthetic loading of the implant. Changes in patients' perceptions were analyzed with the Wilcoxon signed-rank test.

Results: Pretreatment questionnaire was collected from 359 patients. While 245 of them proceeded with implant therapy, 145 received final restoration within the timeframe of the study and completed the post-treatment questionnaires between 1 and 6 months after prosthesis delivery. The most common source of information was dental professions (72.4%). Although patients' perceptions were more realistic at post-treatment, few improper perceptions persisted as only 51% of patients agreed with the statement "There is a chance of dental implant failure," 28% agreed with the statement "Dental implants last longer than natural teeth," and higher percentage of patients agreed with "Dental implant therapy is appropriate for all patients."

Conclusions: Although patients appear to harbor more realistic perceptions of implant therapy, certain improper perceptions still persist at post-treatment. The design of appropriate patient educational program might be essential to correct misperceptions that might affect long term success of implant therapy. This study had been registered on Thai Clinical Trials Registry (TCTR) with the TCTR identification number: TCTR20181101001.
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http://dx.doi.org/10.1111/cid.13036DOI Listing
August 2021

Are oral lichen planus patients at high risk of hepatitis C? A case-control study.

J Stomatol Oral Maxillofac Surg 2021 Jul 28. Epub 2021 Jul 28.

Department of Oral and Maxillofacial Surgery, University Hospital of Giessen and Marburg, UKGM GmbH, Campus Marburg, Faculty of Medicine, Philipps-University of Marburg, Marburg, Germany.

Objective: To assess the correlation between oral lichen planus (OLP) and viral hepatitis C (HCV).

Methods: This retrospective case-control study included a sample of OLP patients in a 3-year interval. The predictor variable was the presence of OLP (yes/no). The outcome variable was the diagnosis of HCV. Other study variables were grouped into demographic, anatomic, and clinical. Descriptive, bi- and multivariate statistics were computed with a significant level at P ≤ 0.05.

Results: The sample was composed of 237 OLP patients (38.8% females) with a mean age of 59.9 ± 17.8 years (range, 17-96), and 948 age- and gender-matched control individuals. The significant higher frequency of HCV was identified in OLP patients (frequency: 19.8% vs. 2.1%; adjusted matched odds ratio [mOR], 9.5; 95% confidence interval [95% CI], 5.98 to 15.91; P < 0.0001; Pearson's Phi coefficient [r], 0.307). In the adjusted model, OLP with HCV was associated with 1) oro-cutaneous manifestations (mOR, 17.58; 95% CI, 1.92 to 161.26; P = 0.0059; Bayesian posterior probability of positive test [W], 96%), 2) any intraoral forms other than reticular/plaque-liked forms (mOR, 0.09; 95% CI, 0.04 to 0.18; P < 0.0001; W, 52%), and 3) poor response to topical corticosteroids (mOR, 0.05; 95% CI, 0.02 to 0.16; P < 0.0001; W, 88%).

Conclusions: OLP, especially oro-cutaneous disease or steroid-refractory OLP, are associated with an increased frequency of HCV. Not only HCV screening in OLP patients, but oral examination in HCV patients, are both recommended as primary preventive measures.
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http://dx.doi.org/10.1016/j.jormas.2021.07.013DOI Listing
July 2021

Comparison of the accuracy of implant placement using different drilling systems for static computer-assisted implant surgery: A simulation-based experimental study.

Clin Implant Dent Relat Res 2021 Aug 19;23(4):635-643. Epub 2021 Jul 19.

Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Chulalongkorn University, Bangkok, Thailand.

Background: Different designs of surgical drilling systems have been developed for the purpose of static Computer-Assisted Implant Surgery (sCAIS), but there is at present little understanding of how design principles affect the accuracy of implant placement.

Purpose: The aim of this in vitro study was to compare the accuracy of implant placement among five drilling systems of sCAIS in a controlled experimental setting.

Materials And Methods: Twenty-five 3D printed models with two edentulous bilateral premolar spaces were allocated to five different drilling systems: group A: sleeve-in-sleeve, group B: sleeve-in-sleeve with self-locking, group C: mounted sleeve-on-drill, group D: integrated sleeve-on-drill with metal sleeve in the guide, group E: integrated sleeve-on-drill without metal sleeve. Models were scanned with CBCT and optical scanner. All implants were digitally planned and 10 implants placed with sCAIS in each group. Postoperative 3D deviation of placed vs planned position was measured by means of platform, apex and angular deviation. Data was analyzed using Kruskal-Wallis test (P ≤ .05). Pairwise comparisons were tested with Dunn's test with adjusted P values.

Results: The overall platform deviation ranged from 0.42 ± 0.12 mm (group B) to 1.18 ± 0.19 mm (group C). The overall apex deviation ranged from 0.76 ± 0.22 mm (group B) to 1.95 ± 0.48 mm (group D). The overall angular deviation ranged from 2.50 ± 0.89 degree (group B) to 5.30 ± 1.04 degree (group E). Group A and B showed significantly less angular deviation than groups D and E (P < .05). There was no statistically significant differences in all parameters between group A and B, as well as between group D and E (P > .05).

Conclusions: Significant differences were found with regards to accuracy among the five sCAIS systems tested, suggesting that the drilling protocol, the devices used and the design principles of the guides could influence the accuracy of implant placement.
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http://dx.doi.org/10.1111/cid.13032DOI Listing
August 2021

Comparing patient-reported outcomes and experiences among static, dynamic computer-aided, and conventional freehand dental implant placement: A randomized clinical trial.

Clin Implant Dent Relat Res 2021 Jul 7. Epub 2021 Jul 7.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Objective: The purpose of this study was to compare patient-reported outcomes and experiences (PROs and PREs) among three techniques of dental implant placement, including (a) conventional freehand, (b) dynamic, and (c) static computer-aided implant surgery (CAIS).

Material And Methods: Ninety patients were randomly assigned to have dental implant placed with one of the three protocols. Participants were asked to fill in a series of self-administered questionnaires assessing (1) preoperative expectations, (2) postoperative healing events during the first week after surgery, and (3) experiences and overall satisfaction with the procedures at 2 weeks. Differences within the groups were analyzed by Wilcoxson signed-rank test. Kruskal-Wallis test was used for comparisons among the three groups.

Results: Eighty-eight patients completed the study. Patients' expectations on chewing difficulty, the postoperative experience of duration of pain, speaking limitations, and impact on routine activities were significantly different among groups (p = 0.04, 0.01, 0.038, and 0.046, respectively). Overall, patients appeared to significantly underestimate the duration of postoperative pain (p = 0.035) and swelling (p = 0.001). No significant difference in magnitude of postoperative pain, swelling, and painkiller consumption was found among the groups. The short-term functional limitations after surgery were deemed acceptable by most participants and 89% were satisfied by the overall procedure.

Conclusions: Surgical placement of dental implant with conventional freehand, static, and dynamic CAIS techniques did not result in any difference in the level of postoperative pain and swelling, and appeared to lead to equal levels of satisfaction as expressed by the patients postoperatively.
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http://dx.doi.org/10.1111/cid.13030DOI Listing
July 2021

A split-mouth randomized clinical trial to evaluate the effect of local and systemic administration of vitamin C on extraction wound healing.

J Oral Sci 2021 Mar 17;63(2):198-200. Epub 2021 Feb 17.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University.

A split-mouth single-blind randomized-controlled clinical trial study was designed to investigate the effect of local and systemic vitamin C administration on extraction wound healing. Thirty patients who underwent bilateral premolar extraction were randomly divided into three group pairs; group 1: control and systemic administration (Con/CSA), group 2: control and a combination of local and systemic administration (Con/CLSA), and group 3: systemic and a combination of local and systemic administration (CSA/CLSA). The vitamin C (600 mg) was taken by swallowing (systemic administration) or slow oral dissolution (combined local and systemic administration). The socket size and radiographic density were evaluated immediately after extraction, and 7 days and 21 days later. The results demonstrated that the percentage radiographic density of new bone formation in the socket did not differ significantly within each group. However, in the CSA and CLSA group there was an improvement of soft tissue healing based in terms of socket depth reduction at 21 days after extraction compared with the control (P < 0.05).
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http://dx.doi.org/10.2334/josnusd.20-0515DOI Listing
March 2021

A German AWMF's S2e/realist synthesis and meta-narrative snapshot of craniomaxillofacial manifestations in COVID-19 patients: Rapid living update on 1 January 2021.

J Stomatol Oral Maxillofac Surg 2021 Jan 30. Epub 2021 Jan 30.

Department of Oral and Maxillofacial Surgery, University Hospital of Giessen and Marburg, UKGM GmbH, Campus Marburg, Faculty of Medicine, Philipps-University of Marburg, Marburg, Germany.

Purposes: To execute a review answering the following question: "Among novel coronavirus disease (COVID19) patients, what are craniomaxillofacial (CMF) manifestations?" based on the RAMESES and the German Association of Scientific Medical Societies (AWMF)'s S2e guidelines.

Methods: We performed a realist synthesis and meta-narrative review extracting data in English, French, German and Thai from PubMed/Medline, Embase, Biomed Central, Cochrane Library, and Thai Journals Online, until 1 January 2021. The primary outcome variable was CMF manifestations grouped into 5 categories: (1) mouth and throat, (2) nose, paranasal sinus, and skull base (3) ocular/orbital and periorbital tissue, (4) ear, and (5) craniofacial skin. Appropriate statistics was computed.

Results: Thirty-seven original articles meeting the inclusion criteria were analysed; all were in English and indexed in PubMed/Medline. Hand searches of their references yielded a total of 101 articles for the review. Most data were in low level of evidence and focused on smell and taste disturbances and non-specific orofacial lesions. Iatrogenic complications may occur in this body region. Conservative measures remained effective and were usually enough for patient care.

Conclusion: Because SARS-CoV-2 infection is new and becomes the stringent worldwide pandemic within a short time period, most of the data on CMF symptoms are of low level evidence. Apart from taste and smell dysfunctions, non-specific CMF lesions can be found and treated conservatively. Treatment complications are possible. Dentists and CMF surgeons are privileged to examine the orofacial region and work closely with colleagues in other specialities to combat this pandemic.
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http://dx.doi.org/10.1016/j.jormas.2021.01.012DOI Listing
January 2021

Factors associated with epiphora following orbital-sparing maxillectomy via modified Weber-Ferguson incision with lower blepharoplasty.

J Surg Oncol 2021 Apr 1;123(5):1246-1252. Epub 2021 Feb 1.

Department of Oral and Maxillofacial Surgery, University Hospital of Giessen and Marburg, Campus Marburg, UKGM GmbH, Faculty of Medicine, Philipps-University of Marburg, Marburg, Germany.

Purpose: The aims of the study were to estimate the frequency of epiphora and to identify factors associated with epiphora after orbital-sparing maxillectomy via modified Weber-Ferguson incision with lower blepharoplasty (OSOSM-MWFILB).

Methods: We performed a retrospective cohort study enrolling a sample derived from the patient population undergoing OSM-MWFILB over a 7-year period. The predictor variables were grouped into demographic, related health status, anatomic, tumor-specific, and therapeutic categories. The primary outcome variable was the presence of postmaxillectomy epiphora (PME). Descriptive, univariate, and multivariate regression mixed-effect models were computed.

Results: The study sample was composed of 134 patients (46.3% females; 71.6% squamous cell carcinomas) with a mean age of 64.7 ± 12.2 years. There were 23 (17.2%) PME events, which were significantly associated with eight variables: male gender, poor general health (ASA III-IV), large vertical defect (Brown and Shaw's class III-IV), squamous cell carcinoma tumor type, big tumor size (T3-4), cervical lymph node metastasis (N1-2), long operating time > 3 h, and adjuvant radio(chemo)therapy in both univariate mixed regression and multivariate Cox hazards analyses. Healing of PME in irradiated patients was significantly delayed.

Conclusions: Ophthalmologic consequences in patients undergoing OSM-MWFILB require particular attention, especially in case of advanced tumors, multiple comorbidities, or long surgery with postoperative radio(chemo)therapy. This emphasizes the importance of appropriate cooperation between the surgeons and ophthalmic colleagues.
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http://dx.doi.org/10.1002/jso.26408DOI Listing
April 2021

Comparison of the accuracy of implant position for two-implants supported fixed dental prosthesis using static and dynamic computer-assisted implant surgery: A randomized controlled clinical trial.

Clin Implant Dent Relat Res 2020 Dec 17;22(6):672-678. Epub 2020 Sep 17.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Background: Computer-assisted implant surgery (CAIS) can facilitate accuracy of single implant placement, but little is known with regards to parallelism between multiple implants.

Purpose: To compare the accuracy of position and parallelism of two implants, using static and dynamic CAIS systems.

Materials And Methods: Thirty patients received two implants (60 implants) randomly allocated to two different CAIS systems. Optimal implant position and absolute parallelism was planned based on preoperative cone beam CT (CBCT). Patients received implants with a surgical guide (static CAIS, n = 30) or real-time navigation (dynamic CAIS, n = 30). Implant three-dimensional deviation and parallelism was calculated after surgery.

Results: The mean 3D deviation in the static and dynamic CAIS group at implant platform were 1.04 ± 0.67 vs 1.24 ± 0.39 mm, at apex were 1.54 ± 0.79 vs 1.58 ± 0.56 mm and angulation were 4.08° ± 1.69° vs 3.78° ± 1.84°, respectively. The angle deviations between two placed implants (parallelism) in static and dynamic CAIS groups were 4.32° ± 2.44° and 3.55° ± 2.29°, respectively. There were no statistically significant differences in all parameters between groups.

Conclusion: Static and dynamic CAIS provides similar accuracy of the 3D implant position and parallelism between two implants.
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http://dx.doi.org/10.1111/cid.12949DOI Listing
December 2020

Post-treatment patient-reported outcome measures in a group of Thai dental implant patients.

Clin Oral Implants Res 2019 Sep 17;30(9):928-939. Epub 2019 Jul 17.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Objective: The aims of this study were to evaluate and analyze the factors affecting patients' perceptions and satisfaction after receiving implant treatment.

Material And Methods: Questionnaires were mailed to 691 patients who had completed implant treatment for at least 6 months. The questionnaire consisted of 23 items, including demographic data, seven items on perceptions, and nine items on satisfaction.

Results: Of the returned 382 questionnaires, 188 and 194 were from patients treated by postgraduate students and specialists, respectively. Dentists were the most common main source of implant information (55.8%). Although 90% of the patients felt that they were well informed about implant treatment, some inaccurate perceptions remained: 18% believed that "Dental implants require less care than natural teeth," 35.6% that "Dental implants last longer than natural teeth," and 75% that "Treatment with dental implants has no risks or complications." Approximately 90% of the patients were satisfied with their chewing, phonetics, aesthetic outcome, and dental implant treatment; however, some were dissatisfied with the cost. Although gender, age, educational level, main source of information, implant number, and implant position had some impact on patients' perceptions and satisfaction; monthly income did not. The clinicians' expertise affected patients' perceptions, but not satisfaction.

Conclusions: Although most patients had accurate perceptions with regards to implant treatment, some misperceptions about the need for a maintenance care still exist after treatment. Most patients were satisfied with their treatment outcome regardless of monthly income and the clinicians' expertise level.
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http://dx.doi.org/10.1111/clr.13500DOI Listing
September 2019

The accuracy of single-tooth implants placed using fully digital-guided surgery and freehand implant surgery.

J Clin Periodontol 2019 09 19;46(9):949-957. Epub 2019 Jul 19.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Aim: This randomized controlled clinical trial (RCT) aimed to compare the accuracy of implant positions between static computer-assisted implant surgery (CAIS) and freehand implant surgery in a single edentulous space.

Materials And Methods: Sites with single edentulous spaces and neighbouring natural teeth were randomized into static CAIS or freehand implant surgery groups. In both groups, digital implant planning was performed using data from cone beam computed tomography (CBCT) and surface scans. In the static CAIS group, a surgical guide was produced and used for fully guided implant surgery, while in the freehand group, the implants were placed in a freehand manner. Postoperative CBCT was used for nine measurements representing the deviations in angles, implant shoulders and apexes between planned and actual implant positions.

Results: Fifty-two patients received 60 single implants. The median (IQR) deviations in angles, shoulders and apexes were 2.8 (2.6)°, 0.9 (0.8) mm and 1.2 (0.9) mm, respectively, in the static CAIS group, and 7.0 (7.0)°, 1.3 (0.7) mm and 2.2 (1.2) mm, respectively, in the freehand group. Statistically significant differences were found in 6 out of nine measured parameters using Mann-Whitney U test (p < 0.05).

Conclusion: Static CAIS provided more accuracy in implant positions than freehand placement in a single edentulous space.
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http://dx.doi.org/10.1111/jcpe.13160DOI Listing
September 2019

The accuracy of static vs. dynamic computer-assisted implant surgery in single tooth space: A randomized controlled trial.

Clin Oral Implants Res 2019 Jun 7;30(6):505-514. Epub 2019 May 7.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Objectives: The aim of this RCT was to compare the accuracy of implant placement between static and dynamic computer-assisted implant surgery (CAIS) systems in single tooth space.

Materials And Methods: A total of 60 patients in need of a single implant were randomly assigned to two CAIS groups (Static n = 30, Dynamic n = 30) and implants were placed by one surgeon. Preoperative CBCT was transferred to implant planning software to plan the optimal implant position. Implants were placed using either stereolithographic guide template (Static CAIS) or implant navigation system (Dynamic CAIS). Postoperative CBCT was imported to implant planning software, and deviation analysis with the planned position was performed. Primary outcomes were the deviation measurements at implant platform, apex, and angle of placement. Secondary outcome was the distribution of the implant deviation into each 3D direction.

Results: The mean deviation at implant platform and implant apex in the static CAIS group was 0.97 ± 0.44 mm and 1.28 ± 0.46 mm, while that in the dynamic CAIS group was 1.05 ± 0.44 mm and 1.29 ± 0.50 mm, respectively. The angular deviation in static and dynamic CAIS group was 2.84 ± 1.71 degrees and 3.06 ± 1.37 degrees. None of the above differences between the two groups reached statistical significance. The deviation of implants toward the mesial direction in dynamic CAIS group was significantly higher than that of the static CAIS (p = 0.032).

Conclusions: Implant placement accuracy in single tooth space using dynamic CAIS appear to be the same to that of static CAIS. (Thai Clinical Trials Registry TCTR20180826001).
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http://dx.doi.org/10.1111/clr.13435DOI Listing
June 2019

Memory T cell subsets in healthy gingiva and periodontitis tissues.

J Periodontol 2018 09 16;89(9):1121-1130. Epub 2018 Aug 16.

Department of Periodontology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Background: In the gingival sulcus, effective and balanced innate and adaptive immune responses against subgingival plaque microbiome are crucial to maintain immune homeostasis. In this study, we investigated the memory T cell subsets in healthy gingiva and periodontitis tissues.

Methods: Anatomical localization of T cells (CD3 , CD4 , and CD8 ) in healthy gingiva and periodontitis tissues were examined immunohistochemically. Subsets of memory T cells from isolated gingival cells were analyzed by flow cytometry using a cocktail of monoclonal antibodies (anti-CD69, anti-CD103, anti-CD45RA, anti-CCR7, anti-CD28, and anti-CD95). Intracellular cytokine staining of interleukin (IL)-17 and interferon (IFN)-γ expression on memory T cells in periodontitis tissues was also investigated.

Results: We found that healthy gingiva contains two memory T cell populations; a CD69 recirculating population and a CD69 gingiva-resident memory T cell population. CD4 T cells with transitional memory (T ) phenotype (CD45RA CCR7 CD28 CD95 ) constitute the major subset within these two populations. A significant increase in the proportion of CD4 CD69 CD103 memory T cells was observed in periodontitis tissues compared with healthy gingiva. CD4 memory T cells from periodontitis tissues produced either IL-17 or IFN-γ whereas CD8 memory T cells produced only IFN-γ.

Conclusions: Our findings suggest that recirculating and gingiva-resident memory T cells could represent an important part of the immune surveillance network in the connective tissue, maintaining periodontal homeostasis. Imbalance of subgingival bacterial communities could damage gingival barrier allowing bacterial antigens to get access to the deeper connective tissue where they activate memory T cells leading to deleterious inflammation; a hallmark of periodontitis.
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http://dx.doi.org/10.1002/JPER.17-0674DOI Listing
September 2018

Gene Expression and Microcomputed Tomography Analysis of Grafted Bone Using Deproteinized Bovine Bone and Freeze-Dried Human Bone.

Int J Oral Maxillofac Implants 2018 03 15;33(3):541–548. Epub 2018 Mar 15.

Purpose: Bio-Oss and demineralized freeze-dried bone allograft (DFDBA) are two commercial bone grafts that have been associated with clinical success for many years. However, there are few in vivo studies regarding their healing mechanism. The purpose of this study was to investigate the level of bone formation using microcomputed tomography (micro-CT) and gene expression in mouse calvaria at 1 and 3 months after bone grafting with deproteinized bovine bone and freeze-dried human bone, and compare them to natural bone healing.

Materials And Methods: Thirty-six mice were divided into three groups (n = 6 per group) according to the type of bone graft used: group 1 (control)-an empty defect without bone graft; group 2-treatment with deproteinized bovine xenograft (Bio-Oss); group 3-treatment with DFDBA. The bone graft was inserted into two 3-mm calvarial defects created on both sides of the parietal bone. At 1 and 3 months, the mice were sacrificed and bone volume was evaluated using micro-CT and gene expression analysis using reverse transcription polymerase chain reaction (RT-PCR).

Results: Micro-CT analysis demonstrated that the parietal bone of mice grafted with Bio-Oss had significantly greater bone volume than both the DFDBA and control groups at both 1 and 3 months. The expression of bone marker genes (Runx2, Osterix [Osx], alkaline phosphatase [ALP], osteopontin [OPN], and osteocalcin [OCN]) were significantly increased from 1 month in both Bio-Oss and DFDBA groups at 3 months. Runx2 and Osx had significantly higher expression in the Bio-Oss and DFDBA groups compared to the control group at 3 months. No statistically significant difference was observed among groups after 1 month.

Conclusion: These results showed that both bone graft materials promoted bone regeneration. Bio-Oss demonstrated high osteoconductive properties.
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http://dx.doi.org/10.11607/jomi.6234DOI Listing
March 2018

Human Memory B Cells in Healthy Gingiva, Gingivitis, and Periodontitis.

J Immunol 2016 08 22;197(3):715-25. Epub 2016 Jun 22.

Immunology Laboratory, Faculty of Dentistry, Chulalongkorn University, Bangkok 10330, Thailand;

The presence of inflammatory infiltrates with B cells, specifically plasma cells, is the hallmark of periodontitis lesions. The composition of these infiltrates in various stages of homeostasis and disease development is not well documented. Human tissue biopsies from sites with gingival health (n = 29), gingivitis (n = 8), and periodontitis (n = 21) as well as gingival tissue after treated periodontitis (n = 6) were obtained and analyzed for their composition of B cell subsets. Ag specificity, Ig secretion, and expression of receptor activator of NF-κB ligand and granzyme B were performed. Although most of the B cell subsets in healthy gingiva and gingivitis tissues were CD19(+)CD27(+)CD38(-) memory B cells, the major B cell component in periodontitis was CD19(+)CD27(+)CD38(+)CD138(+)HLA-DR(low) plasma cells, not plasmablasts. Plasma cell aggregates were observed at the base of the periodontal pocket and scattered throughout the gingiva, especially apically toward the advancing front of the lesion. High expression of CXCL12, a proliferation-inducing ligand, B cell-activating factor, IL-10, IL-6, and IL-21 molecules involved in local B cell responses was detected in both gingivitis and periodontitis tissues. Periodontitis tissue plasma cells mainly secreted IgG specific to periodontal pathogens and also expressed receptor activator of NF-κB ligand, a bone resorption cytokine. Memory B cells resided in the connective tissue subjacent to the junctional epithelium in healthy gingiva. This suggested a role of memory B cells in maintaining periodontal homeostasis.
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http://dx.doi.org/10.4049/jimmunol.1600540DOI Listing
August 2016

Nasal appearance after secondary cleft rhinoplasty: comparison of professional rating with patient satisfaction.

Oral Maxillofac Surg 2016 Jun 22;20(2):195-201. Epub 2016 Apr 22.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Objective: The purpose of this study was to compare professional rating and patient satisfaction of nasal appearance after secondary cleft rhinoplasty.

Method: We used a cross-sectional study design and enrolled German adults with nonsyndromic unilateral or bilateral cleft lip and/or palate (UCLP and BCLP, respectively) undergoing secondary cleft rhinoplasty from January 2001 to December 2013. The predictor variable was professional rating. The outcome variable was patient satisfaction with postoperative nasal aesthetics. Other study variables included patient age and gender, type of surgery, and patient rating of nasal function. Appropriate descriptive and univariate statistics were computed, and a P value of <0.05 was regarded as statistically significant. Inter-rater reliability was assessed by the use of Cohen's kappa coefficient.

Results: The study sample consisted of 242 adult cleft patients of mean age of 22.1 ± 9.2 years (range 14-64), including 97 females (40 %) and 176 unilateral clefts (73 %). Most of the patients reported good function (82 %) and good aesthetics (74 %). The main professional rating was good aesthetics (65 %). Analysis of inter-observer reliability revealed significant differences between patient satisfaction and professional assessment (κ = 0.385; P < 0.0001).

Conclusions: Although most of the patients were satisfied with the functional and aesthetic results of secondary cleft rhinoplasty, patient self-assessment of nasal appearance differed from professional assessment.
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http://dx.doi.org/10.1007/s10006-016-0555-4DOI Listing
June 2016

Dental Student Hand Hygiene Decreased With Increased Clinical Experience.

J Surg Educ 2016 May-Jun;73(3):400-8. Epub 2016 Feb 6.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. Electronic address:

Objective: To investigate the effectiveness, related knowledge, attitudes, and practices of hand hygiene (HH) among dental students with different levels of clinical experience.

Design: This was a cross-sectional analytical study. Bacterial samples on the participants' hands were obtained using a swab technique before and after handwashing, for oral surgical procedures. After culturing, the colony-forming units were counted. Self-reported questionnaires reflecting the knowledge, attitudes, and practices related to HH were completed by the participants.

Setting: This study was performed in a primary oral health care institution, Faculty of Dentistry, Chulalongkorn University (Bangkok, Thailand). Bacterial samples and self-reported questionnaires were collected in the Department of Oral and Maxillofacial Surgery. Bacterial culture was performed in the Department of Microbiology.

Participants: The 120 participants comprised first, second, third-year clinical training students (CTs), and postgraduate dental students (PGs) (32, 34, 30, and 24 participants, respectively).

Results: More than 99% of the bacteria were eliminated from the participants' hands after handwashing. Significantly higher numbers of bacteria were recovered from the hands of the PGs compared with those of the CTs, and the hands of the third-year CTs compared with those of the first-year CTs (p < 0.001), after HH. The first-year CTs had the highest attitude scores, whereas the PGs had the lowest practice scores. The knowledge scores were similar in all groups.

Conclusion: HH effectiveness, attitudes, and practices of dental students decreased as students gained more clinical experience, whereas knowledge did not. Our results suggest that HH instruction should be given throughout the duration of dental students' education.
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http://dx.doi.org/10.1016/j.jsurg.2015.12.007DOI Listing
January 2017

Pyoderma gangrenosum-like oral ulcerations in an elderly patient.

Gerodontology 2015 Dec;32(4):309-13

Department of Oral Medicine, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Objective: To present a case of pyoderma gangrenosum (PG)-like oral ulcerations in an elderly patient.

Background: PG is an uncommon idiopathic, ulcerative, chronic inflammatory cutaneous disorder of unknown etiology, which is associated with systemic diseases found in more than 50% of patients. Oral lesions of PG are extremely rare and have not been previously reported on chronic leukemia patient.

Clinical Report: This report presents the first case of a 73 year-old man who had PG-like oral ulcerations which offered the possibility of an initial finding of chronic myeloid leukemia.

Conclusion: Clinicians should always take into consideration that PG in the oral mucosa is a recalcitrant ulcer and can precede the development of underlying clonal malignancy.
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http://dx.doi.org/10.1111/ger.12158DOI Listing
December 2015

Factors associated with postrhinoplasty mucous cyst in cleft lip patients.

Oral Maxillofac Surg 2015 Dec 30;19(4):391-6. Epub 2015 May 30.

Department of Oral, Craniomaxillofacial and Facial Plastic Surgery, Faculty of Medicine, University Hospital of Leipzig, Leipzig, Germany.

Purpose: The purpose of this study was to identify risk factors associated with postrhinoplasty mucous cyst (PMC) among adult cleft patients undergoing rhinoplasty. PMC has been reported sporadically in the literature. Its aetiology is uncertain. The purpose of this study was to determine whether three factors, (1) patient age, (2) surgical trauma, and/or (3) use of a nasal septal cartilage graft (NSCG), were risk factors for PMC.

Methods: We organized a retrospective, single-center study and enrolled cleft rhinoplasty patients treated between January 2003 and December 2008. The predictor variables included age at surgery, use of a NSCG, and length of surgery. The primary outcome was presence of PMC. Other study variables included demographic, surgical, and postoperative data. Appropriate descriptive and univariate statistics were calculated, and P < 0.05 was regarded as indicative of statistical significance.

Results: The sample comprised 314 cleft rhinoplasty patients (118 females; 37.6 %) with a mean age of 14.9 ± 10.7 years (range 0-65). Three patients had a PMC after secondary cleft rhinoplasty. Average time to disease was 26 ± 19.3 months after surgery (range 12-48). There was no significant association between the presence of the PMC and the three predictor variables-patient's age, NSCG transplantation, and protracted surgery (P > 0.05).

Conclusions: These study findings suggest that young age, use of a NSCG, and protracted surgery are not risk factors for PMC. The prevalence of PMC is greater for cleft patients after rhinosurgery than for noncleft patients.
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http://dx.doi.org/10.1007/s10006-015-0510-9DOI Listing
December 2015

Factors affecting scientific productivity of German oral-maxillofacial surgery training centers: a retrospective cohort study.

Oral Maxillofac Surg 2015 Sep 25;19(3):259-65. Epub 2015 Feb 25.

Research Group for Clinical and Psychosocial Research, Evidence-Based Surgery and Ethics in Oral and Maxillofacial Surgery, Faculty of Medicine, University Hospital of Leipzig, Leipzig, Germany,

Purpose: To identify factors associated with scientific productivity (SP) of German oral-maxillofacial surgery (OMFS) training centers.

Materials And Methods: This retrospective cohort study was composed of a set of data from German OMFS training centers. A total of eight predictor variables were grouped into demographic, structural, and personal categories. The outcome variables were average publications in 2013 per senior staff, and percentage of OMFS trainees with >1 publications. Descriptive and univariate statistics were computed using P < 0.05.

Results: The sample included outputs from 62 OMFS departments (34 [54.8 %] university-based; 46 [74.2 %] in large cities). Average publications were 2.4 ± 3 per senior staff (range, 0-27), and 160 trainees (31.7 %) published >1 papers. The number of publications and productive trainees was not linked to department name and number of female senior staffs, but publication count was significantly increased when the hospital was in a metropolis (P = 0.018) or university-based (P < 0.0001), the OMFS' chairperson and >3 staffs within the department had a postdoctoral degree (German "Habilitation") (P = 0.013 and <0.0001), and the chairperson had h-index >10 or the first/last authorship in 2013 (P < 0.0001). Female senior surgeons were less scientifically productive than the male ones (P = 0.01).

Conclusion: SP of German OMFS training centers is greatly different across the country and influenced by city size, university base, educational backgrounds, and research activities of chairpersons and senior staffs. This helps students, trainees, and young surgeons to reach the career choice that is personally appropriate. The involved organizations may need to encourage research output of less productive surgeons/centers. Increasing postdoctoral-qualified staffs will increase SP of the department.
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http://dx.doi.org/10.1007/s10006-015-0489-2DOI Listing
September 2015

Alu hypomethylation in smoke-exposed epithelia and oral squamous carcinoma.

Asian Pac J Cancer Prev 2013 ;14(9):5495-501

Department of Anatomy, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand E-mail :

Background: Alu elements are one of the most common repetitive sequences that now constitute more than 10% of the human genome and potential targets for epigenetic alterations. Correspondingly, methylation of these elements can result in a genome-wide event that may have an impact in cancer. However, studies investigating the genome-wide status of Alu methylation in cancer remain limited.

Objectives: Oral squamous cell carcinoma (OSCC) presents with high incidence in South-East Asia and thus the aim of this study was to evaluate the Alu methylation status in OSCCs and explore with the possibility of using this information for diagnostic screening. We evaluated Alu methylation status in a) normal oral mucosa compared to OSCC; b) peripheral blood mononuclear cells (PBMCs) of normal controls comparing to oral cancer patients; c) among oral epithelium of normal controls, smokers and oral cancer patients.

Materials And Methods: Alu methylation was detected by combined bisulfite restriction analysis (COBRA) at 2 CpG sites. The amplified products were classified into three patterns; hypermethylation ((m)C(m)C), partial methylation (uC(m)C+(m)C(u)C), and hypomethylation ((u)C(u)C).

Results: The results demonstrate that the %(m)C(m)C value is suitable for differentiating normal and cancer in oral tissues (p=0.0002), but is not significantly observe in PBMCs. In addition, a stepwise decrease in this value was observed in the oral epithelium from normal, light smoker, heavy smoker, low stage and high stage OSCC (p=0.0003). Furthermore, receiver operating characteristic (ROC) curve analyses demonstrated the potential of combined %mC or %(m)C(m)C values as markers for oral cancer detection with sensitivity and specificity of 86.7% and 56.7%, respectively.

Conclusions: Alu hypomethylation is likely to be associated with multistep oral carcinogenesis, and might be developed as a screening tool for oral cancer detection.
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http://dx.doi.org/10.7314/apjcp.2013.14.9.5495DOI Listing
June 2014

LINE-1 and Alu hypomethylation in mucoepidermoid carcinoma.

BMC Clin Pathol 2013 Mar 19;13:10. Epub 2013 Mar 19.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok 10330, Thailand.

Background: Mucoepidermoid carcinoma (MEC) can be classified into low-, intermediate-, and high-grade tumors based on its histological features. MEC is mainly composed of three cell types (squamous or epidermoid, mucous and intermediate cells), which correlates with the histological grade and reflects its clinical behavior. Most cancers exhibit reduced methylation of repetitive sequences such as Long INterspersed Element-1 (LINE-1) and Alu elements. However, to date very little information is available on the LINE-1 and Alu methylation status in MEC. The aim of this study was to investigate LINE-1 and Alu element methylation in MEC and compare if key differences in the methylation status exist between the three different cell types, and adjacent normal salivary gland cells, to see if this may reflect the histological grade.

Methods: LINE-1 and Alu element methylation of 24 MEC, and 14 normal salivary gland tissues were compared using Combine Bisulfite Restriction Analysis (COBRA). Furthermore, the three different cell types from MEC samples were isolated for enrichment by laser capture microdissection (LCM), essentially to see if COBRA was likely to increase the predictive value of LINE-1 and Alu element methylation.

Results: LINE-1 and Alu element methylation levels were significantly different (p<0.001) between the cell types, and showed a stepwise decrease from the adjacent normal salivary gland to the intermediate, mucous and squamous cells. The reduced methylation levels of LINE-1 were correlated with a poorer histological grade. In addition, MEC tissue showed a significantly lower level of LINE-1 and Alu element methylation overall compared to normal salivary gland tissue (p<0.001).

Conclusions: Our findings suggest that LINE-1 methylation differed among histological grade mucoepidermoid carcinoma. Hence, this epigenetic event may hold value for MEC diagnosis and prognostic prediction.
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http://dx.doi.org/10.1186/1472-6890-13-10DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3610265PMC
March 2013

Patterns and possible roles of LINE-1 methylation changes in smoke-exposed epithelia.

PLoS One 2012 18;7(9):e45292. Epub 2012 Sep 18.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Tobacco smoking and reduced methylation of long interspersed element-1 (LINE-1) are crucial in oral carcinogenesis. 5'UTR of human LINE-1 sequence contains several CpG dinucleotides which are methylated in various proportions (0-100%). Methylation levels of many LINE-1s in cancer were reduced, hypomethylated. The hypomethylation of each LINE-1 locus can promote instability of genome and repress expression of a gene located on that same chromosome. This study investigated if cigarette smoking influences LINE-1 methylation of oral mucosal cells. The methylation of human LINE-1 in clinically normal oral mucosa of current smokers was compared to non-smokers. By using the combined bisulphite restriction analysis, each LINE-1 sequence was categorised into 4 patterns depending on the methylation status and location of the two 18-bp successive CpG from 5' to 3' including (m)C(m)C, (u)C(u)C, (m)C(u)C and (u)C(m)C. Of these, (m)C and (u)C represent methylated and unmethylated CpG, respectively. The DNA bisulphite sequence demonstrated that most CpGs of (m)C(m)C and (u)C(u)C were methylated and unmethylated, respectively. Nevertheless, some CpGs of each (m)C(u)C or (u)C(m)C allele were methylated. Imaging of the digestion products was used to generate %methylation value. No significant difference in the overall LINE-1 methylation level but the differences in percentages of some methylation patterns were discovered. The %(m)C(m)C and %(u)C(u)C increased, while the %(m)C(u)C decreased in current smokers (p = 0.002, 0.015, and <0.0001, respectively). Additionally, the lower %(m)C(u)C still persisted in persons who had stopped smoking for over 1 year (p = 0.001). The %(m)C(u)C also decreased in the higher pack-year smokers (p = 0.028). Smoking possibly altered (m)C(u)C to (m)C(m)C and (u)C(u)C forms, and changes (u)C(m)C to (u)C(u)C forms. In conclusion, smoking changes methylation levels of partial methylated LINE-1s and increased the number of hypo- and hypermethylated loci. These hypomethylated LINE-1s may possess carcinogenesis potential. Moreover, LINE-1 methylation patterns may be useful for monitoring oral carcinogenesis in smokers.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0045292PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445447PMC
February 2013

Notch signalling inhibits the adipogenic differentiation of single-cell-derived mesenchymal stem cell clones isolated from human adipose tissue.

Cell Biol Int 2012 ;36(12):1161-70

Department of Oral and Maxillofacial Surgery, Chulalongkorn University, Bangkok, Thailand.

ADSCs (adipose-derived mesenchymal stem cells) are candidate adult stem cells for regenerative medicine. Notch signalling participates in the differentiation of a heterogeneous ADSC population. We have isolated, human adipose tissue-derived single-cell clones using a cloning ring technique and characterized for their stem cell characteristics. The role of Notch signalling in the differentiation capacity of these adipose-derived single-cell-clones has also been investigated. All 14 clones expressed embryonic and mesenchymal stem cell marker genes. These clones could differentiate into both osteogenic and adipogenic lineages. However, the differentiation potential of each clone was different. Low adipogenic clones had significantly higher mRNA expression levels of Notch 2, 3 and 4, Jagged1, as well as Delta1, compared with those of high adipogenic clones. In contrast, no changes in expression of Notch signalling component mRNA between low and high osteogenic clones was found. Notch receptor mRNA expression decreased with the adipogenic differentiation of both low and high adipogenic clones. The γ-secretase inhibitor, DAPT (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-(S)-phenylglycine t-butyl ester), enhanced adipogenic differentiation. Correspondingly, cells seeded on a Notch ligand (Jagged1) bound surface showed lower intracellular lipid accumulation. These results were noted in both low and high adipogenic clones, indicating that Notch signalling inhibited the adipogenic differentiation of adipose ADSC clones, and could be used to identify an adipogenic susceptible subpopulation for soft-tissue augmentation application.
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http://dx.doi.org/10.1042/CBI20120288DOI Listing
April 2013

MxA expression induced by α-defensin in healthy human periodontal tissue.

Eur J Immunol 2012 Apr;42(4):946-56

Department of Periodontology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Although periodontal tissue is continually challenged by microbial plaque, it is generally maintained in a healthy state. To understand the basis for this, we investigated innate antiviral immunity in human periodontal tissue. The expression of mRNA encoding different antiviral proteins, myxovirus resistance A (MxA), protein kinase R (PKR), oligoadenylate synthetase (OAS), and secretory leukocyte protease inhibitor (SLPI) were detected in both healthy tissue and that with periodontitis. Immunostaining data consistently showed higher MxA protein expression in the epithelial layer of healthy gingiva as compared with tissue with periodontitis. Human MxA is thought to be induced by type I and III interferons (IFNs) but neither cytokine type was detected in healthy periodontal tissues. Treatment in vitro of primary human gingival epithelial cells (HGECs) with α-defensins, but not with the antimicrobial peptides β-defensins or LL-37, led to MxA protein expression. α-defensin was also detected in healthy periodontal tissue. In addition, MxA in α-defensin-treated HGECs was associated with protection against avian influenza H5N1 infection and silencing of the MxA gene using MxA-targeted-siRNA abolished this antiviral activity. To our knowledge, this is the first study to uncover a novel pathway of human MxA induction, which is initiated by an endogenous antimicrobial peptide, namely α-defensin. This pathway may play an important role in the first line of antiviral defense in periodontal tissue.
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http://dx.doi.org/10.1002/eji.201141657DOI Listing
April 2012

Improved measurement of LINE-1 sequence methylation for cancer detection.

Clin Chim Acta 2011 Jan 12;412(3-4):314-21. Epub 2010 Nov 12.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.

Background: Methylation of long interspersed nuclear element-1 (LINE-1) sequences varies among normal cells and it is often decreased in cancer genomes and white blood cells (WBC) of cancer patients. Current measurement techniques of genome-wide level are inadequate because LINE-1 methylation is distinctive at each locus. Here, we improved the detection of cancer by combining information of LINE-1 methylation pattern and level.

Methods: Combined bisulfite restriction analysis (COBRA) of LINE-1, COBRA LINE-1, was used to test cancer cell lines, two oral rinse cohorts, and WBC from normal and cancer patients. COBRA LINE-1 separated LINE-1 sequences into 4 products depending on the methylation statuses of 2 CpG dinucleotides, as follows: 2 unmethylated CpGs ((u)C(u)C), partial methylation ((m)C(u)C), 1 methylated CpG ((m)C), and 1 unmethylated CpG ((u)C).

Results: The association between (m)C(u)C and (u)C(u)C was directly correlated in normal cells (r=0.4895, p=0.0009) but inversely correlated in cancer (r=-0.8979, p=0.0002). Oral rinse AUC values of (u)C(u)C were 0.763 and 0.926 and methylation levels were 0.707 and 0.621, respectively. (u)C(u)C, but not overall methylation level, differentiated cancer WBC from normal (p=0.0082 and p=0.4830, respectively).

Conclusion: LINE-1 partial methylation represents hypomethylation in normal cells but hypermethylation in cancer cells. This information improves LINE-1 methylation detection in cancer.
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http://dx.doi.org/10.1016/j.cca.2010.10.030DOI Listing
January 2011

LINE-1 methylation patterns of different loci in normal and cancerous cells.

Nucleic Acids Res 2008 Oct 6;36(17):5704-12. Epub 2008 Sep 6.

Inter-Department Program of BioMedical Sciences, Faculty of Graduate School, Chulalongkorn University, Bangkok 10330, Thailand.

This study evaluated methylation patterns of long interspersed nuclear element-1 (LINE-1) sequences from 17 loci in several cell types, including squamous cell cancer cell lines, normal oral epithelium (NOE), white blood cells and head and neck squamous cell cancers (HNSCC). Although sequences of each LINE-1 are homologous, LINE-1 methylation levels at each locus are different. Moreover, some loci demonstrate the different methylation levels between normal tissue types. Interestingly, in some chromosomal regions, wider ranges of LINE-1 methylation levels were observed. In cancerous cells, the methylation levels of most LINE-1 loci demonstrated a positive correlation with each other and with the genome-wide levels. Therefore, the loss of genome-wide methylation in cancerous cells occurs as a generalized process. However, different LINE-1 loci showed different incidences of HNSCC hypomethylation, which is a lower methylation level than NOE. Additionally, we report a closer direct association between two LINE-1s in different EPHA3 introns. Finally, hypermethylation of some LINE-1s can be found sporadically in cancer. In conclusion, even though the global hypomethylation process that occurs in cancerous cells can generally deplete LINE-1 methylation levels, LINE-1 methylation can be influenced differentially depending on where the particular sequences are located in the genome.
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http://dx.doi.org/10.1093/nar/gkn571DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2553567PMC
October 2008

Detection of LINE-1s hypomethylation in oral rinses of oral squamous cell carcinoma patients.

Oral Oncol 2009 Feb 19;45(2):184-91. Epub 2008 Aug 19.

Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok 10330, Thailand.

This study aimed to (i) investigate long interspersed nuclear element-1 (LINE-1) methylation levels of oral squamous cell carcinomas (OSCCs), the major type of oral malignancies; and (ii) investigate whether the hypomethylation of LINE-1s can be detected in oral rinses of OSCC patients. The combined bisulfite restriction analysis polymerase chain reaction (PCR) of LINE-1s (COBRALINE-1) was used. We found that tissues from OSCC specimens had lower methylation levels of LINE-1s than cells collected from the oral rinses of normal volunteers. Interestingly, cells collected from oral rinses of OSCC patients also revealed hypomethylated LINE-1s at the same level as OSCC tissues. There was no difference in the level of hypomethylation due to stages, locations, histological grades, and history of betel chewing, smoking and/or alcohol consumption. In conclusion, OSCCs possessed global hypomethylation and this alteration could be detected from oral rinses of OSCC patients by a simple PCR technique, COBRALINE-1. Therefore, COBRALINE-1 of oral rinses may be applied for non-invasive detection of oral malignancies.
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http://dx.doi.org/10.1016/j.oraloncology.2008.05.002DOI Listing
February 2009
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