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Medicina (Kaunas, Lithuania) Sep 2022The excessive use of smartphones for various tasks led to a new adverse postural phenomenon called text neck. The aim of this study was to investigate the effect of the...
The excessive use of smartphones for various tasks led to a new adverse postural phenomenon called text neck. The aim of this study was to investigate the effect of the text neck posture (TNP) on static occlusion by using the T-Scan III occlusal diagnostic system. : Nineteen subjects (aged 20 to 24 years) were considered for this research. They had normal values for anterior overbite and overjet, Angle Class I occlusion, no posterior crossbite, and no signs or symptoms of cervical or temporo-mandibular disorders. Occlusal registrations were performed with the T-Scan III system in a normal, neutral head posture (NHP), as well as in the TNP. The investigated parameters were: occlusion time (OT), asymmetry index of the occlusal force (AOF), percent of the maximum movie force (%MMF), and the time elapsed from the last occlusal contact until the maximum intercuspation (MAT-OTB). The last three parameters were analyzed in the maximum area frame (MA) of the registrations. For the statistical analysis of the recorded data, the Wilcoxon Signed Ranks test and the Spearman's correlation coefficient were used. The following values were obtained in NHP and in TNP: for AOF, 14.88 ± 10.39% and 18.04 ± 12.83%, respectively; for OT, 1.34 ± 1.84 s and 1.32 ± 1.8 s, respectively; for the %MMF, 97.5 ± 2.83% and 96.31 ± 3.17%, respectively; for MAT-OTB, 2.08 ± 1.82 s and 1.45 ± 2.3 s, respectively. There were no statistically significant differences between the static occlusal parameters measured in NHP and those in TNP. However, the high values of the AOF and OT in NHP revealed an imbalance of the occlusal force distribution between the right and left side in maximum intercuspation (MI), as well as a lack of simultaneity of static occlusal contacts. Furthermore, there was a significant, direct, and strong correlation between OT and AOF in NHP. The NHP should not be used as the starting position in TNP simulations in T-Scan studies, so as to avoid statistically insignificant differences between static occlusion in NHP and TNP. The healthy standing subjects, with normal occlusal relationships from the clinical point of view, revealed an occlusal instability in NHP when examined with the T-Scan.
Topics: Bite Force; Chest Pain; Dental Occlusion; Humans; Malocclusion; Posture; Temporomandibular Joint Disorders
PubMed: 36143980
DOI: 10.3390/medicina58091303 -
Journal of Prosthodontic Research Jan 2023Purpose This literature review aimed to investigate predictability of re-establishment of the occlusion following placement of restorations at an increased OVD, duration... (Review)
Review
Purpose This literature review aimed to investigate predictability of re-establishment of the occlusion following placement of restorations at an increased OVD, duration and to assess the quality of the available evidence.Methods An electronic search of articles using MEDLINE (1946-01/2019), EMBASE (1974-01/2019) and the Cochrane databases was undertaken. Search terms included dental restoration, vertical dimension and time. Studies involving placement of restorations at an increased OVD and recorded the time taken for the occlusion to re-establish were included. Eligibility assessments were carried out independently by two reviewers who also undertook independent extraction of predefined data fields, including study quality indicators.Results The search provided 61 results with 11 being relevant. A further 5 papers were identified for full text analysis. 4 papers used similar data from previous studies and 3 were excluded after full text assessment.. A final total of 9 papers were included in the review. It was indicated that the technique of placing restorations at an increased OVD appears to be clinically predictable in terms of re-establishment of occlusion and appears to occur most rapidly in younger patients.Conclusions The time taken for the occlusion to re-establish was between 15 days to 24 months. However, there is a need for prospective studies to evaluate the process in terms of success, predictive variables and specifically how long the process takes and this information would be helpful for both clinicians and patients, so that they know what to expect before embarking on a treatment.
Topics: Humans; Vertical Dimension; Dental Occlusion; Prospective Studies
PubMed: 35185109
DOI: 10.2186/jpr.JPR_D_21_00106 -
Clinical Oral Investigations Apr 2022The aim of this study was to examine the occlusion of anterior teeth in individuals with shortened dental arch (SDA).
OBJECTIVES
The aim of this study was to examine the occlusion of anterior teeth in individuals with shortened dental arch (SDA).
MATERIAL AND METHODS
In a case-control clinical study, 41 individuals with SDA and 41 individuals with complete dental arch (CDA) participated. The CDA control group was matched for age and gender. Testing for occlusal contacts of anterior maxillary teeth was conducted by biting on foil strips (8 µm) with subjectively normal bite force (NBF) and maximal bite force (MBF). The data was analyzed on individual and tooth levels.
RESULTS
The median rates of anterior maxillary teeth with occlusal contacts were 0.67 (NBF) and 0.83 (MBF) in the SDA group and 0.50 (NBF) and 0.83 (MBF) in the CDA group. Within both groups, the contact rates were significantly higher in MBF. The group difference with NBF was significant. A generalized linear model showed that the odds of an anterior maxillary tooth to have an occlusal contact were greater in the SDA both for NBF with an odds ratio (OR) 2.277 and MBF with an OR 1.691.
CONCLUSIONS
The findings suggest effective compensatory mechanisms relative to the occlusal function in individuals with SDA.
CLINICAL RELEVANCE
The study delivers further evidence regarding the SDA concept as a viable option in the management of posterior tooth loss.
Topics: Bite Force; Dental Arch; Dental Occlusion; Humans; Jaw, Edentulous, Partially; Tooth; Tooth Loss
PubMed: 34889979
DOI: 10.1007/s00784-021-04317-5 -
Journal of Oral Rehabilitation Jan 2001There are several terms that identify proposed paradigms for the way things ought to be carried out in the health sciences: evidence-based, cause-and-effect, diagnostic... (Review)
Review
There are several terms that identify proposed paradigms for the way things ought to be carried out in the health sciences: evidence-based, cause-and-effect, diagnostic gold-standard, patient-centred-outcomes, risk assessment, cost/benefit/risk, and efficacious/effective. Collectively these paradigms exhibit varying degrees of interdependence, and have the potential for changing the way dentistry is practiced. A paradigm can be thought of as a standard by which research and health science ought to be conducted and evaluated. In this sense scientists and clinicians try to figure out how to account for various observations and phenomena dictated by paradigms or models of health care; however, it may become necessary to shift to new paradigms that are more consistent with scientific and clinically reality. Some of the potential effects of these shifting paradigms on the practice and teaching of occlusion and temporomandibular disorders are considered.
Topics: Bruxism; Cost-Benefit Analysis; Dental Occlusion; Dental Occlusion, Traumatic; Education, Dental; Evidence-Based Medicine; Humans; Malocclusion; Patient-Centered Care; Research Design; Risk Assessment; Science; Temporomandibular Joint Disorders; Treatment Outcome
PubMed: 11298903
DOI: 10.1046/j.1365-2842.2001.00658.x -
The Angle Orthodontist Apr 1999The importance of occlusion as an etiologic factor in signs and symptoms of TMD has been a source of controversy. Very few studies have examined occlusion-dictated... (Review)
Review
The importance of occlusion as an etiologic factor in signs and symptoms of TMD has been a source of controversy. Very few studies have examined occlusion-dictated condylar position using instrumentation, and none has compared an ideal sample against an untreated control. The purpose of this study was to determine if there is a relationship between condylar axis position as determined by the occlusion and signs and symptoms of TMD, using the condylar position indicator (CPI). A sample of subjects with ideal occlusions, defined as centric relation approximating centric occlusion, was compared with a control sample of untreated subjects. The comparison was based on written patient histories, clinical exams, and CPI measurements. The ideal sample of 30 subjects was selected from a population that had undergone full-mouth reconstruction using gnathologic principles that included centric relation (CR) being coincident with centric occlusion (CO). The control group consisted of 30 untreated subjects from the general population and was matched with the ideal sample with regard to sex. A duplicate written exam was given to the subjects in the ideal sample to assess symptoms prior to treatment. The CR bite registration technique developed by Roth was used. When the pre- and posttreatment examination scores of the ideal sample were compared, an 84% reduction in symptoms was found after treatment. A high correlation (p<.001) between signs and symptoms of TMD and CPI values was documented. Since condylar axis position is dictated upon closure of the dentition into maximum intercuspation and since condylar axis position was shown in this study to be strongly correlated with TMD symptomatology, it can be concluded that a statistically significant relationship exists between occlusion-dictated condylar position and symptoms of TMD.
Topics: Adult; Case-Control Studies; Centric Relation; Dental Occlusion, Centric; Female; Humans; Jaw Relation Record; Male; Malocclusion; Mandibular Condyle; Medical History Taking; Middle Aged; Reference Values; Regression Analysis; Reproducibility of Results; Surveys and Questionnaires; Temporomandibular Joint Dysfunction Syndrome
PubMed: 10227550
DOI: 10.1043/0003-3219(1999)069<0103:CAPADB>2.3.CO;2 -
The Angle Orthodontist 1990The purpose of this study was to explore the possible significant sex difference in occlusion, provide information about the occlusal variation among Egyptians, and... (Review)
Review
The purpose of this study was to explore the possible significant sex difference in occlusion, provide information about the occlusal variation among Egyptians, and present an epidemiologic panorama of dental occlusion among different ethnic world populations. The hypothesis was that the occlusal variation is not independent of sex. A sample of 501 female and male adult subjects was studied. Normal occlusion, Angle's classification of malocclusion, and the Dewey-Anderson modifications for typifications were recorded. Chi-square tests were used. The results obtained from this study indicate that a significant sex difference in occlusion exists for normal occlusion, Angle Class I, and Angle Class III. Further, considering an anterior crossbite as the sole indicator of an Angle Class III malocclusion is erroneous; an anterior crossbite may exist in other classes, and Angle Class III type 1 (edge-to-edge) is more prevalent than either Class III type 2 (normal anterior overbite) or type 3 (anterior crossbite). Although numerically different, occlusal variation follows a universal general distributional pattern for most world populations. Some speculations are presented for clinical implications and for research suggestions.
Topics: Adolescent; Adult; Dental Occlusion; Dental Occlusion, Centric; Egypt; Female; Humans; Male; Malocclusion; Sex Characteristics
PubMed: 2202237
DOI: 10.1043/0003-3219(1990)060<0207:EPODO>2.0.CO;2 -
Medicina Oral, Patologia Oral Y Cirugia... Jan 2012The future of dental practice is closely linked to the utilization of computer-based technology, specifically virtual reality, which allows the dental surgeon to... (Review)
Review
The future of dental practice is closely linked to the utilization of computer-based technology, specifically virtual reality, which allows the dental surgeon to simulate true life situations in patients. The virtual articulator has been designed for the exhaustive analysis of static and dynamic occlusion, with the purpose of substituting mechanical articulators and avoiding their errors. These tools will help both odontologists and dental prosthetists to provide the best individualized treatment for each patient. The present review analyzes the studies published in the literature on the design, functioning and applications of virtual articulators. A Medline-PubMed search was made of dental journals, with the identification of 137 articles, of which 16 were finally selected. The virtual articulator can simulate the specific masticatory movement of the patient. During mandibular animation, the program calculates the sites where the opposing teeth come into contact. The studies made to assess the reliability of the virtual articulator show good correspondence in visualization of the number and position of the dynamic contacts. The virtual articulator is a precise tool for the full analysis of occlusion in a real patient.
Topics: Dental Articulators; Dental Occlusion; Humans
PubMed: 22157663
DOI: 10.4317/medoral.17147 -
Scientific Reports Mar 2019Morphological integration and modularity are important for understanding phenotypic evolution because they constrain variation subjected to selection and enable...
Morphological integration and modularity are important for understanding phenotypic evolution because they constrain variation subjected to selection and enable independent evolution of functional and developmental units. We report dental integration and modularity in representative otariid (Eumetopias jubatus, Callorhinus ursinus) and phocid (Phoca largha, Histriophoca fasciata) species of Pinnipedia. This is the first study of integration and modularity in a secondarily simplified dentition with simple occlusion. Integration was stronger in both otariid species than in either phocid species and related positively to dental occlusion and negatively to both modularity and tooth-size variability across all the species. The canines and third upper incisor were most strongly integrated, comprising a module that likely serves as occlusal guides for the postcanines. There was no or weak modularity among tooth classes. The reported integration is stronger than or similar to that in mammals with complex dentition and refined occlusion. We hypothesise that this strong integration is driven by dental occlusion, and that it is enabled by reduction of modularity that constrains overall integration in complex dentitions. We propose that modularity was reduced in pinnipeds during the transition to aquatic life in association with the origin of pierce-feeding and loss of mastication caused by underwater feeding.
Topics: Animals; Caniformia; Dental Occlusion; Dentition; Female; Male; Phylogeny; Tooth
PubMed: 30862801
DOI: 10.1038/s41598-019-40956-1 -
PloS One 2021Dentistry is confronted with the functional and aesthetic consequences that result from an increased prevalence of misaligned and discrepant dental occlusal relations in...
Dentistry is confronted with the functional and aesthetic consequences that result from an increased prevalence of misaligned and discrepant dental occlusal relations in modern industrialised societies. Previous studies have indicated that a reduction in jaw size in response to softer and more heavily processed foods during and following the Industrial Revolution (1,700 CE to present) was an important factor in increased levels of poor dental occlusion. The functional demands placed on the masticatory system play a crucial role in jaw ontogenetic development; however, the way in which chewing behaviours changed in response to the consumption of softer foods during this period remains poorly understood. Here we show that eating more heavily processed food has radically transformed occlusal power stroke kinematics. Results of virtual 3D analysis of the dental macrowear patterns of molars in 104 individuals dating to the Industrial Revolution (1,700-1,900 CE), and 130 of their medieval and early post-medieval antecedents (1,100-1,700 CE) revealed changes in masticatory behaviour that occurred during the early stages of the transition towards eating more heavily processed foods. The industrial-era groups examined chewed with a reduced transverse component of jaw movement. These results show a diminished sequence of occlusal contacts indicating that a dental revolution has taken place in modern times, involving a dramatic shift in the way in which teeth occlude and wear during mastication. Molar macrowear suggests a close connection between progressive changes in chewing since the industrialization of food production and an increase in the prevalence of poor dental occlusion in modern societies.
Topics: Biological Evolution; Biomechanical Phenomena; Dental Occlusion; Dentistry; Humans; Mastication; Molar; Tooth
PubMed: 34910787
DOI: 10.1371/journal.pone.0261404 -
BMC Oral Health Oct 2018Infant Oral Mutilation (IOM) includes germectomy and early extraction of primary and permanent incisors and canines, primarily in the lower jaw. The aim of the present...
BACKGROUND
Infant Oral Mutilation (IOM) includes germectomy and early extraction of primary and permanent incisors and canines, primarily in the lower jaw. The aim of the present study was to examine the prevalence and impact of IOM, involving the removal of mandibular permanent incisors and/or canines, on dental occlusion and Oral Health-Related Quality of Life (OHRQoL) among Kenyan adolescents from Maasai Mara.
METHODS
In a cross-sectional study, 284 adolescents (14-18 yrs. of age) participated in an oral examination and an interview, using a structured questionnaire on age, gender, medical history, and IOM practice. For the analysis of the dental occlusion, participants with IOM, in terms of absence of two or more permanent teeth in the mandibular incisor and/or canine tooth segments (IOM group), were compared to participants who had all six incisors and canines present in the oral cavity (control group). OHRQoL was assessed using child perception questionnaire (CPQ11-14).
RESULTS
The majority of the participants (61%) had been exposed to IOM, among whom 164 (95%) had absence of two mandibular central incisors. More individuals in the IOM group had maxillary overjet exceeding 5 mm than in the control group (50.9% vs. 20%, p < 0.001). Nineteen (11%) subjects in the IOM group had mesial occlusion in contrast to none in the control group (p < 0.001). The mean and median total CPQ scores and the mean and median CPQ domain scores were low in both groups with no significant differences between the groups.
CONCLUSIONS
Approximately two-thirds of the study population presented with IOM, with the majority of them missing two mandibular permanent central incisors. Although some participants with IOM had substantial maxillary overjet and mesial occlusion, only few of them showed substantial effect on their OHRQoL.
Topics: Cross-Sectional Studies; Dental Occlusion; Female; Humans; Infant; Kenya; Male; Mandible; Medicine, African Traditional; Prevalence; Quality of Life; Surveys and Questionnaires; Tooth Extraction
PubMed: 30355318
DOI: 10.1186/s12903-018-0631-2