Comparison of the Intensity of Biofilm Production by Oral Microflora and Its Adhesion on the Surface of Zirconia Produced in Additive and Subtractive Technology: An In Vitro Study.

BACKGROUND: This in vitro study set out to find out how well oral cavity-dwelling bacteria can form biofilms and adhere on the surfaces of zirconium oxide samples created by 3D printing and milling technologies. METHODS: 5 strains of microorganisms were used for the study, and 40 zirconium oxide samples were prepared, which were divided into two groups (n = 20)-20 samples produced using removal technology comprised the control group, while 20 samples produced by 3D printing technology comprised the test group. The prepared samples were placed in culture media of bacteria and fungi that naturally occur in the oral cavity. Then, the intensity of biofilm build-up on the samples was determined using qualitative and quantitative methods. The results for both materials were compared with each other. RESULTS: No variations in the degree of biofilm deposition on zirconium oxide samples were found for the microorganisms Streptococcus mutans, Pseudomonas aeruginosa, Enterococcus faecalis, and Staphylococcus aureus. For Candida albicans fungi, more intense biofilm deposition was observed on samples made using 3D printing technology, but these differences were not statistically significant. CONCLUSION: The biofilm accumulation intensity of ceramics produced by additive technology is comparable to that of milled zirconium oxide, which supports the material's broader use in clinical practice from a microbiological perspective. This ceramic has demonstrated its ability to compete with zirconium oxide produced by milling techniques in in vitro experiments, but sadly, no in vivo tests have yet been found to determine how this material will function in a patient's oral cavity.

Mechanical characteristics of zirconia produced additively by 3D printing in dentistry - A systematic review with meta-analysis of novel reports.

OBJECTIVES: This study was aimed at comparing the mechanical parameters of ceramics made using the addition and subtraction technique. METHODS: A search was performed on four search engines on 5th April 2023. Quality assessment was performed using study type-specific scales. Where possible, a meta-analysis was performed. SOURCES: Data were extracted from four search engines: PubMed, PubMed Central, Embase, Web of Science, Scopus. STUDY SELECTION: The search strategy identified 686 potential articles. 19 papers were subject to qualitative analysis, and data from 11 papers were meta-analysed. The included studies were of high or medium quality. All included papers were in-vitro studies. No clinical trials were found in the literature. SIGNIFICANCE: Ceramics made in the additive technology in terms of mechanical parameters can compete with ceramics made in the milling technology. There are no clinical studies yet that would indicate the use of this type of material for permanent restorations in patients. Studies presented in the literature vary greatly in terms of study design and reporting of results. The research did not receive external funding.

Distribution of Elements in Beaver (Castor fiber) Tooth Enamel as a Sign of Environmental Adaptation: the Special Role of Fe, Co, Mg, and Fluorides (F-).

The aim of the study was to investigate the distribution of elements (Ca, Mg, Fe, P, Zn, Na, K, Cu, Cr, Mo, Co, Se) analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES) and fluorides (F-) determined potentiometrically using an ion-selective electrode in the enamel of European beaver (Castor fiber) teeth. Material for the study was tooth enamel collected from lower jaws from the skulls of the animals borrowed from museum collections (animals inhabited north-western Poland). The results of our study indicate the important role of F- as an element that can affect the hardness and strength of beaver tooth enamel. Critical to the function of beaver teeth (i.e., shearing and crushing wood) is the presence of elements such as Fe in the central incisor labial aspect (orange layer of the incisor enamel), Mg in the inner side of the incisor enamel, and Co and F- in the enamel of the molars. Thanks to the high content of these elements, the enamel is durable and the teeth are adapted to the nutritional and ecological characteristics of this mammalian species. Our study on the distribution of elements in the enamel of beaver teeth may also be important for the understanding of the enamel mineralization processes, determining how elements change the properties of the materials, and exploring the relationship between the environment and life history of the beaver.

Comparison of Dental Zirconium Oxide Ceramics Produced Using Additive and Removal Technology for Prosthodontics and Restorative Dentistry-Strength and Surface Tests: An In Vitro Study.

BACKGROUND: The aim of this in vitro study was to determine the mechanical and functional properties of zirconium oxide ceramics made using 3D printing technology and ceramics produced using conventional dental milling machines. METHODS: Forty zirconia samples were prepared for this study: the control group consisted of 20 samples made using milling technology, and the test group consisted of 20 samples made using 3D printing technology. Their surface parameters were measured, and then their mechanical parameters were checked and compared. Density, hardness, flexural strength and compressive strength were tested by performing appropriate in vitro tests. After the strength tests, a comparative analysis of the geometric structure of the surfaces of both materials was performed again. Student's t-test was used to evaluate the results (p < 0.01). RESULTS: Both ceramics show comparable values of mechanical parameters, and the differences are not statistically significant. The geometric structure of the sample surfaces looks very similar. Only minor changes in the structure near the crack were observed in the AM group. CONCLUSION: Ceramics made using additive technology have similar mechanical and surface parameters to milled zirconium oxide, which is one of the arguments for the introduction of this material into clinical practice. This in vitro study has shown that this ceramic can compete with zirconium made using CAD/CAM (Computer-Aided Design and Computer-Aided Manufacturing) methods.

Fluoride varnish, ozone and octenidine reduce the incidence of white spot lesions and caries during orthodontic treatment: randomized controlled trial.

This randomized, parallel, controlled trial assessed the effect of fluoride varnish, ozone and octenidine on white spot lesions (WSLs) and caries during orthodontic treatment. Patients were enrolled between 1st September 2017 and 31st August 2020 at initiation of orthodontic treatment in Department of Interdisciplinary Dentistry Pomeranian Medical University in Szczecin, Poland. All participants were randomly assigned to four study and one control groups using number random generator. However, investigators were not blinded due to the nature of the study. Groups I, II, III, IV had professional cleaning and varnishing (5% NaF) every 4 weeks. Groups II and IV had in-office ozone therapy before varnishing, groups III and IV received domestic octenidine mouthrinse. Group K had no professional hygienic or prophylactic procedures. WSLs were assessed at T0 and then every 4 weeks (T1-T4) and caries-at T0 and T4. The specific objective was to assess the influence of fluoride varnish, ozone and octenidine on the incidence of white spot lesions and caries during orthodontic treatment. The primary outcome of this report was the highest number of WSLs in group K and the lowest percentage of patients with WSLs in group IV. Each group comprised 30 randomized participants; they were all analyzed. No WSLs were found at T0, but they were stated in all groups at T4. The numbers of patients with WSLs significantly increased between T0-T4 in groups I and K. Group IV had the lowest percentage of patients with WSLs in T1-T4. WSLs in group IV were found no earlier than at T2. Group K had the highest percentage of WSLs at T4: 26%. At T0 all the groups had DMFs above 0 with a significant increase at T4. No side effects of the introduced prophylaxis were observed in any group. Caries is an important problem of fixed orthodontic treatment. Even an extremely intensive prophylaxis could not completely prevent WSLs and caries. Simultaneous application of fluoride varnish, ozone gas exposure and octenidine appears to have a beneficial effect in limiting the development of WSLs.Trial registration: NCT04992481.

Chronotype Profile, Stress, Depression Level, and Temporomandibular Symptoms in Students with Type D Personality.

Background: Despite a growing interest in the types of human circadian activity, different chronotypes and personality-related issues have been rarely studied. It has already been emphasized that 'stress personality' is considered a risk factor for certain psychosomatic diseases and may be a temporomandibular disorders (TMDs) predictor. Therefore, an attempt has been made to analyze the chronotypes, stress levels, stress factors, and the occurrence of depression and TMDs in students with type D personalities. People with this personality trait tend to experience negative emotions more­depression, anxiety, anger, or hostility­yet may have a negative image of themselves and report somatic complaints. Aim: The aim of this study was to analyze the importance of the chronotype profile for the level of stress perceived, as well as for the occurrence of depression and TMDs in people with type D personalities. Material and Methods: The study has been conducted on a group of 220 physical therapy students. The study group G1 consisted of 110 participants with type D personalities, the control group G2 consisted of the same number of participants without the stress personality. All participants have been analyzed for the chronotype (MEQ), stress perception (PSS10), the occurrence of depression (Beck scale-BDI), the occurrence of TMDs symptoms and have completed the stress factor assessment questionnaire during the study, followed by DS14 questionnaire­a tool for assessing the prevalence of type D personality. Results: In students with type D personalities (G1), the definitely evening and evening chronotypes have been significantly more predominant than in the control group (G2). A significantly higher number of stressors and TMDs symptoms have been observed in the respondents from the G1 group than in the control group (<0.001). Univariate logistic regression analysis showed that type D personality was strongly associated with a more frequent occurrence of all TMD symptoms. Additionally, a significant influence of the evening chronotype on the occurrence of type D personality was observed. Among the potential confounding variables, female gender and a mild and moderate degree of depression have an impact on the occurrence of type D personality (p < 0.05). In the multivariate model, adjusted with the above-mentioned factors, an increased risk of the type D personality trait was found. Conclusion: The evening chronotype and type D personality may imply greater feelings of stress, greater depression, and more frequent symptoms of TMDs in young adults.

Cytotoxic Potential of Denture Adhesives on Human Fibroblasts-In Vitro Study.

(1) In recent years, there has been a significant increase in the availability of denture adhesives for stabilizing removable dentures. The aim of the present study was to assess the cytotoxicity of three denture adhesives on human fibroblasts. (2) Methods: Three denture adhesives were analyzed. Fibroblast cultures were established for the study and control groups in order to assess the incidence of necrosis and to evaluate the microscopic intracellular alterations induced. Following incubation with (study groups) or without adhesives (control group), trypan blue dye exclusion assay was used to determine the number of viable and/or dead cells. Microscopic specimens were stained with haematoxylin and eosin, scanned, digitally processed and then analyzed by a histopathologist. (3) Results: All three denture adhesives analyzed demonstrated various toxic effects in vitro on human fibroblast: quantitative evaluation-45.87-61.13% reduction of cell viability (p = 0.0001) and slight to moderate cytotoxicity in qualitative evaluation. (4) Conclusions: Denture adhesive creams demonstrated a toxic effect on human fibroblasts in vitro in quantitative and qualitative evaluation. In vivo observations are needed to find out if denture adhesives present a cytotoxic effect in patients.

Determining the occlusal plane: a literature review.

Objective: The purpose of the present review was to demonstrate the utility of articulator systems and link instrumentation in determining the occlusal plane. The impact of the natural head position and anatomical landmarks on the occlusal plane location has been reported in the literature. Properly chosen instrumentation and management methods eliminate errors in determining the occlusal plane.Methods: The PubMed and the Dentistry & Oral Sciences Source (through EbscoHost) databases were searched for ways to minimize the occurrence of errors when registering and determining the occlusal plane location, with or without the use of face-bows. A hand search and citation mining supplemented the results.Results: Overall, 11 original approaches to occlusal plane determination were identified.Discussion: Identified methods of occlusal plane transfer are based on real or virtual solutions. Owing to the large variety of devices, additional comparative studies are needed.

Effect of Personality Type on the Occurrence of Temporomandibular Disorders-A Cross-Sectional Study.

BACKGROUND: Personality traits are one of the major factors influencing the behavior and functioning of an individual, and they play a crucial role in the development of psychosomatic disorders and diseases. This paper aimed to evaluate the importance of personality traits in temporomandibular disorder (TMDs) development using the NEO-FFI Personality Inventory by Paul Costa and Robert McCrae (the Five-Factor Model of Personality, known as the Big Five). Moreover, the relationship between personality type and the intensity of dysfunctional changes in the stomatognathic system was assessed using the NEO-FFI Personality Inventory by Paul Costa and Robert McCrae (the Five-Factor Model of Personality, known as the Big Five). MATERIAL AND METHODS: The study included a group of 75 adult participants (aged 19-52) with TMD diagnosed according to DC/TMD criteria and a control group of 75 participants without symptoms of dysfunction. The study consisted of a questionnaire and clinical study; the questionnaire included the NEO-FFI psychological questionnaire and a self-authored one. The clinical part consisted of extra- and intraoral dental examinations. RESULTS: Participants who clenched their teeth showed a greater degree of conscientiousness than those who did not exhibit this symptom (p = 0.048). Presence of headaches was correlated with greater severity of neuroticism (p = 0.001). Moreover, participants with enamel cracks showed a lower intensity of extraversion (p = 0.039), and those with worn hard dental tissues showed a higher intensity of neuroticism (p = 0.03), a lower intensity of conscientiousness (p = 0.01), and a lower intensity of extroversion (p = 0.046). Acoustic symptoms during mandibular movements were found to be linked with a higher level of neuroticism (p = 0.020), a lower level of extraversion (p = 0.035), and a lower level of conscientiousness, whereas pain upon mandibular movements were linked to a lower level of conscientiousness (p = 0.025). Participants with pain upon palpation of the masticatory muscles showed a lower level of conscientiousness (p = 0.01) compared to those without pain symptoms. Episodes of mandibular blockage or problems with its adduction depend on the intensity of conscientiousness (p = 0.007). Moreover, people from the study group with high levels of neuroticism showed lower protrusion values (p = 0.016). CONCLUSION: The intensity of individual personality traits was found to be associated with some TMDs in comparison to healthy controls.

Type D Personality and Stomatognathic System Disorders in Physiotherapy Students during the COVID-19 Pandemic.

BACKGROUND: A person's response to stressors is largely dependent on their personality traits that affect the way stress is controlled and relieved. This article is a quantitative analysis assessing the importance of the distressed personality in the development of stomatognathic system disorders (SSDs) in physiotherapy students during the COVID-19 pandemic. OBJECTIVE: The goal of the research was to assess the presence of type D personality in students with symptoms of stomatognathic system disorders. MATERIAL AND METHOD: The research was carried out among 300 physiotherapy students. The data were collected using the form of the occurrence of symptoms of SS disorders developed for the purpose of the study and the standardized psychological DS14 questionnaire. RESULTS: In a group of 300 students, the presence of type D personality was found in 160 people (53.3%). People with type D personality had symptoms of SS disorders more often than the group without stressful personality traits. There was a significant difference between the groups regarding all the examined symptoms. In the group of people with type D personality, the most frequently reported symptoms of SS disorders included: headache (51.3%), pain in the neck and shoulder girdle (43.1%), and teeth clenching (35.6%). As many as 70% of the respondents in the group with symptoms of SS disorders (P1) had type D personality, whereas in the asymptomatic group (P2) this result was 23.3%. There was a significant difference between the groups (p = 0.00). Statistically significantly higher values of both D personality dimensions were observed in women than in men with symptoms of SS disorders. In people reporting symptoms of SS disorders, higher average values were observed in both dimensions of type D personality. There were significant differences between the groups. CONCLUSION: type D personality may contribute to the development of symptoms of stomatognathic disorders.

COL5A1 RS12722 Is Associated with Temporomandibular Joint Anterior Disc Displacement without Reduction in Polish Caucasians.

Numerous reports describe the association between the single-nucleotide polymorphism (SNP) rs12722 and rs13946 in the COL5A1 gene and injuries, such as Achilles tendon pathology, anterior cruciate ligament (ACL) injuries, and tennis elbow. Hence, there were no studies investigating COL5A1 and temporomandibular joint (TMJ) pathology. The aim of this study is to evaluate the relationship between COL5A1 rs12722 and rs13946 SNPs and TMJ articular disc displacement without reduction (ADDwoR). In this case-control study, the study group consisted of 124 Caucasian patients of both sexes. Each patient had a history of ADDwoR no more than 3 months prior. The control group comprised 126 patients with no signs of TMD according to DC/TMD. Genotyping of the selected SNPs was performed by real-time PCR using TaqMan probes. The significance of the differences in the distribution of genotypes was analyzed using Pearson's chi-square test. Logistic regression modeling was performed to analyze the influence of the 164 investigated SNPs on ADDwoR. The COL5A1 marker rs12722 turned out to be statistically significant (p-value = 0.0119), implying that there is a difference in the frequencies of TMJ ADDwoR. The distribution of rs12722 SNPs in the study group TT(66), CC(27), CT(31) vs. control group TT(45), CC(26), CT(51) indicates that patients with CT had an almost 2.4 times higher likelihood of ADDwoR (OR = 2.41) than those with reference TT (OR = 1), while rs13946 genotypes were shown to be insignificant, with a p-value of 0.1713. The COL5A1 rs12722 polymorphism is a risk factor for ADDwoR in the Polish Caucasian population.

The Influence of the COVID-19 Pandemic on the Stress Levels and Occurrence of Stomatoghnatic System Disorders (SSDs) among Physiotherapy Students in Poland.

BACKGROUND: This study is a quantitative analysis examining the impact of the COVID-19 pandemic on the occurrence of stress and stomatognathic system disorders (SSDs) among students of physiotherapy. OBJECTIVE: To assess stress severity, strategies of coping with stress and the presence of type D personality among physiotherapy students including those with symptoms of stomatognathic system disorders. MATERIAL AND METHODS: The research was conducted from October to December 2020 on a sample of 188 students of physiotherapy. The data were collected using a survey form related to the occurrence of SS disorders symptoms and standardized psychological questionnaires, such as the Perceived Stress Scale (PSS)-10, Mini-Cope, and the type-D Scale (DS14), developed for the purpose of this study. RESULTS: Women experiencing at least one of the SS disorder-related symptoms were characterized by a significantly higher level of stress and a type D personality (p < 0.05). Among men, these differences were not statistically significant (p > 0.05). On the basis of the strategies of coping with stress, i.e., positive self-reevaluation, discharging and blaming oneself, and taking psychoactive substances, it is possible to predict the intensity of stress during the pandemic in the group of the examined students. Among the reported symptoms of SS, headache was a significant predictor of stress, which was accompanied by an increase in the intensity of stress by nearly 0.2 measurement points. Students with higher levels of stress showed more symptoms of type D personality, and those with more severe symptoms of SS showed higher levels of stress. CONCLUSIONS: People prone to stress and having type D personality traits should be assessed for the presence of SS disorders.

Electromyographic activity analysis of temporal and masseter muscles in psychoactive substance addicts. / Elektromiograficzna analiza czynnosci miesni zwaczy i skroniowych u osób uzaleznionych od substancji psychoaktywnych.

OBJECTIVES: As part of this study, a comparative analysis of the temporal and masseter muscle electrical activity at rest and during mandible excursion positions (protrusion, laterotrusion and maximal occlusion) was performed among patients aged 21 to 68 years. METHODS: Each of three groups: opioid addicts, alcohol addicts and the control group - consisted of 30 individuals (90 individuals in total, including 37 females and 53 males). Electrodes were placed on the masseter venters and mandibular movements were executed: right/left lateral, protrusion, intercuspation, rest and MVC. Then the same routine was applied to the anterior parts of temporal muscles. RESULTS: Based on EMG data in alcohol addicts, higher electrical activity of masseters and temporal muscles was observed during the mandible excursions, compared to the control group. In comparison of opiate addicts to healthy controls, no statistical significance was observed in electrical activity of masseter and temporal muscles. CONCLUSIONS: On the basis of the conducted research, a conclusion can be drawn that alcohol addiction significantly affects the function of the largest muscles of the stomatognathic system.

Pressure Algometry Evaluation of Two Occlusal Splint Designs in Bruxism Management-Randomized, Controlled Clinical Trial.

The aim of this pilot study was to evaluate the short-term effectiveness of two different occlusal devices and their impact on the pressure pain threshold (PPT) values among patients who reported to the Dental Prosthetics Outpatient Clinic of Pomeranian Medical University (Szczecin, Poland) and who were diagnosed with probable bruxism. Two groups were formed (A and B) to which patients were assigned randomly. Each group used a different occlusal splint for bruxism management. The occlusal appliance by Okeson, or the bimaxillary splint, was used overnight by each patient for 30 days of the study. The PPT was measured twice, at the first visit and after 30 days of using each occlusal device, with Wagner Paintest FPX 25 algometer. Bruxism was diagnosed based on data from the patient's medical history and from the physical examination. Nocturnal Bruxism Criteria according to the International Classification of Sleep Disorders (Third Edition) was used for the patient's evaluation. Results: similar pain factor (PF) reduction was observed in both the examined groups, regardless of the device used; canine guidance and no guidance were similarly effective in terms of increasing pain resilience.

COL12A1 Single Nucleotide Polymorphisms rs240736 and rs970547 Are Not Associated with Temporomandibular Joint Disc Displacement without Reduction.

Temporomandibular disorders (TMDs) may affect up to 25% of the population, with almost 70% of these TMD cases developing malpositioning of the disc over time in what is known as internal derangement (ID). Despite significant efforts, the molecular mechanism underlying disease progression is not yet very well known. In this study, the role of COL12A1 rs970547 and rs240736 polymorphisms as potential genetic factors regulating ID was investigated. The study included 124 Caucasian patients of both sexes after disc displacement without reduction (DDwoR) in either one or two temporomandibular joints (TMJs), either of which meet the criteria for this condition. All patients underwent clinical examination and 3D digital imaging. The COL12A1 rs970547 and rs240736 polymorphisms were evaluated. There were no statistically significant differences in the chi-square test between the study group and healthy controls. The examined COL12A1 rs240736 and rs970547 polymorphisms do not contribute to DDwoR in Polish Caucasians.

The Impact of SARS-CoV-2 Outbreak on the Polish Dental Community's Standards of Care-A Six-Month Retrospective Survey-Based Study.

Currently, SARS-CoV-2 is the primary pathogen worldwide, disrupting most of our everyday activities. The study aim was to evaluate its impact on the Polish dental community, standards of care, health, and welfare. METHODS: A Google Forms survey was conducted among 303 dental practitioners. RESULTS: Of respondents, 54.93% curbed the number of patients in the last six months, 34.21% declared no changes, and 10.86% reported an increase; whereas 70.7% of the respondents reported a treatment price increase within the same period (27.96% and 1.32% reported no changes and a decrease, respectively). Of the respondents, 15.5% did not close their businesses during the first wave of the pandemic. Most declared 1 or 2 month break, 30.7% and 34.7%, respectively. Some reported 3, 4, or 5 month breaks (15.84%, 1.32%, and 0.99%, respectively), and only two respondents (0.66%) did not admit patients at all. Headache episodes were more frequent among female dentists before the pandemic; after the pandemic, headache frequency increased among both sexes. Temporomandibular disorders (TMDs) were more frequent among women (p = 0.017). CONCLUSIONS: Most Polish dentists followed SARS-CoV-2 recommendations and restricted their practices to admitting only patients with pain or incomplete treatment. Decreased sleep parameters, head, back, and neck pain, were observed. This situation may affect dental health conditions in Polish society over time.

The Importance of Type D Personality in the Development of Temporomandibular Disorders (TMDs) and Depression in Students during the COVID-19 Pandemic.

BACKGROUND: a type D personality is a factor in a person's susceptibility to general mental stress, especially during the COVID-19 pandemic. Although many studies were conducted on the relationships among stressful situations, an individual's personality, depression, and the occurrence of various diseases, e.g., cardiovascular disease or cancer, there are no analogous data on people with temporomandibular disorders (TMDs). AIM: the assessment of TMDs and depression symptoms in students with type D personality. MATERIAL AND METHODS: the research was carried out with the participation of 240 physiotherapy students. The study group (G1) consisted of 120 participants with type D personalities, the control group (G2) consisted of the same number of participants, without "stress" personalities. All subjects were assessed for the occurrence of TMD symptoms, as well as for depression and anxiety symptoms, using the Beck Depression Inventory (BDI), based on the proprietary questionnaire. RESULTS: in students with type D personality symptoms, TMDs occurred significantly more often and in greater number (p = 0.00) than in those without stress personalities. The exception was the symptom of increased muscle tension, which showed no statistical difference (p = 0.22). Among the 240 respondents, depression was found in 128 people (53.3%). In the group of students with type D personalities, depression was significantly more frequent than in the group without type D personalities (p = 0.00). In participants with depression, TMD symptoms were more common, i.e., headaches, neck, and shoulder girdle pain, TMJ acoustic symptoms, increased masticatory muscle tension, teeth clenching, and teeth grinding. There was no significant difference between the incidence of depression and TMJ pain and jaw locking. There was a significant interaction between the occurrence of headaches and acoustic symptoms and the occurrence of depression. For headache and depression interactions, the OR was >1; based on the results, we may assume that a headache depends more on the occurrence of depression rather than it being a symptom of a TMJ disorder in people with type D personalities. CONCLUSION: type D personality and depression may contribute to the development of TMD symptoms.

Association of Estrogen Receptor 1 and Tumor Necrosis Factor α Polymorphisms with Temporomandibular Joint Anterior Disc Displacement without Reduction.

OBJECTIVES: The aim of this study was to investigate the role of ESR1 rs1643821 and TNF-α rs1800629 as potential genetic factors regulating anterior disc displacement without reduction-mediated inflammatory pathway. BACKGROUND: The temporomandibular joint is a complex synovial joint that allows mandibular movement in three directions. Although temporomandibular disorders are widespread, limited data is available on the biochemical characteristics of the displaced disc and quality of the surrounding soft tissue. Changes in degenerative tissue provoke disc displacement which involves secretion of inflammatory markers and sequential conversion of fibroblast-like cells into chondrocyte-like cells. Due to the high occurrence in female adolescents, the potential role of sex hormones in temporomandibular joint disorders has been speculated. Furthermore, anterior disc displacement without reduction severely affects the quality of life. METHODS: 124 Caucasian patients with a history of at least one anterior disc displacement without reduction within 3 months were enrolled. Anterior disc displacement without reduction was diagnosed based on clinical examination, diagnostic criteria (DC)/TMD, and cone-beam computed tomography/magnetic resonance imaging (CBCT/MRI). The control group consisted of 126 patients with no temporomandibular joint disorders. Genotyping of two single nucleotide polymorphisms, estrogen receptor 1 (ESR1) rs1643821, and tumor necrosis factor α (TNF-α) rs1800629 was performed. RESULTS: ESR1 rs1643821 showed significant P values (using chi-square analysis) revealing the difference in anterior disc displacement without reduction frequencies while TNF-α rs1800629 polymorphism was found to be statistically insignificant when compared to the control group. Furthermore, patients with a genotype of ESR1 rs1643821 showed a decreased probability (OR = 0.412) against anterior disc displacement without reduction when compared to the GG genotype (OR = 1). CONCLUSION: ESR1 rs1643821 with A allele frequency was lower in patients with anterior disc displacement without reduction compared to the control group. Thus, the rs1643821 variant is significantly associated with susceptibility to the anterior disc displacement without a reduction in European Caucasians. Conversely, TNF-α rs1800629 was a statistically insignificant factor against anterior disc displacement without reduction when compared to the control group.

The Usefulness of the Pressure Algometer in the Diagnosis and Treatment of Orofacial Pain Patients: A Systematic Review.

OBJECTIVES: The pressure pain threshold (PPT) may be an efficient approach to screen and evaluate orofacial pain. However, the results of previous PPT studies have varied greatly. The aim of this paper was to determine whether the PPT is an efficient approach for screening and evaluating orofacial pain. METHODS: The search yielded 123 articles. After removal of duplicates and screening of abstracts, 32 articles were selected for further evaluation. The Cochrane Collaboration tool for assessing the risk of bias was used for the evaluation of the studies. RESULTS: The studies covered a total of 4403 adult patients, aged 16-62, and 30 children. The studies investigated the reliability and validity of the PPT (measured by a pressure algometer) in TMD patients. The PPT was investigated in relation to headache, menstrual cycle, oral contraception, occlusal interference, and occlusal appliances. Generally, the risk of bias was low to unclear. Some structural limitations were inherent in the studies, such as small samples and short duration of the testing involved. Also, the analyzed studies lacked consistency in study design and patient management. Pressure increase values differed from 20 kPa/s to 50 kPa/s and from 0.5 kg/cm2/s to 2 kg/cm2/s. Descriptions of the PPT examination points also varied, from very precise and repeatable to a simple listing of anatomical points. The number of measurements varied from 1 to 5 at each visit. The intervals ranged from 5 seconds to 15 minutes. However, some studies confirmed that the pressure algometer is an effective tool for determining the source of orofacial pain. CONCLUSIONS: Based on the analyzed articles, the authors argue that the PPT is not an efficient approach for screening and evaluating orofacial pain. What is more, it should not be used as the only diagnostics tool for patients with orofacial pain. Importantly, however, additional factors should be considered in the future for the evaluation of the PPT, including body symmetry and posture, hormone levels and the menstrual phase in women, and the use of medications and its influence on the PPT. Further clinical trials should also be performed on the PPT, examining head and neck pain patients, with more precise study design and larger samples.

Skin incision versus laser - the influence of different techniques on scar formation and lymphatic drainage in rats. A preliminary report.

INTRODUCTION: The constantly rising number of skin malignancies and increasing cancer awareness encourage more people to visit outpatient clinics in order to have various skin lesions removed. Despite the fact that scarring is a physiological response to any excision procedure, minimizing the size of it is a goal of every good practitioner. Therefore the question arises whether different techniques used to remove skin lesions may impact the formation and quality of skin scars. AIM: To perform an evaluation of skin scars formed by laser and surgical incisions and their influence on lymphatic outflow in rats. MATERIAL AND METHODS: Five male rats were used. Using methylene blue, the migration of dye through lymphatic channels of the lower extremity was measured. Afterwards, transverse incisions were made distally using laser and a surgical blade. Wounds were left to heal by secondary intention. After 4 weeks dye migration assessment was repeated and tissue samples were obtained for microscopic evaluation. RESULTS: Wounds after surgical incisions healed entirely. Wounds after laser treatment had not healed, with a visible area of granulation tissue and hair loss. Significantly worse dye migration was observed in rat extremities after laser therapy than after surgical incision (p = 0.007). CONCLUSIONS: The results of the study show that the size of the scar can depend on the incision technique used. Larger scars after laser therapy limit the lymphatic flow of the skin, which may have an adverse effect on mapping sentinel lymph nodes. However, this hypothesis requires further research.