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Occlusal Factors (occlusal + factor)
Selected AbstractsThe role of orthodontics in temporomandibular disordersJOURNAL OF ORAL REHABILITATION, Issue 6 2010A. MICHELOTTI Summary, Temporomandibular Disorder (TMD) is the main cause of pain of non-dental origin in the oro-facial region including head, face and related structures. The aetiology and the pathophysiology of TMD is poorly understood. It is generally accepted that the aetiology is multifactorial, involving a large number of direct and indirect causal factors. Among such factors, occlusion is frequently cited as one of the major aetiological factors causing TMD. It is well known from epidemiologic studies that TMD-related signs and symptoms, particularly temporomandibular joint (TMJ) sounds, are frequently found in children and adolescents and show increased prevalence among subjects between 15 and 45 years old. Aesthetic awareness, the development of new aesthetic orthodontic techniques and the possibility of improving prosthetic rehabilitation has increased the number of adults seeking orthodontic treatment. The shift in patient age also has increased the likelihood of patients presenting with signs and symptoms of TMD. Because orthodontic treatment lasts around 2 years, orthodontic patients may complain about TMD during or after treatment and orthodontists may be blamed for causing TMD by unsatisfied patients. This hypothesis of causality has led to legal problems for dentists and orthodontists. For these reasons, the interest in the relationship between occlusal factors, orthodontic treatment and TMD has grown and many studies have been conducted. Indeed, claims that orthodontic treatment may cause or cure TMD should be supported by good evidence. Hence, the aim of this article is to critically review evidence for a possible association between malocclusion, orthodontic treatment and TMD. [source] Clinical value of 12 occlusal features for the prediction of disc displacement with reduction (RDC/TMD Axis I group IIa)JOURNAL OF ORAL REHABILITATION, Issue 5 2009G. CHIAPPE Summary, The purpose of this study is to quantify the clinical value of 12 occlusal variables for the prediction of disc displacement with reduction diagnosed according to research diagnostic criteria (RDC)/temporomandibular disorder (TMD). Twelve occlusal features were clinically assessed by the same three operators. The sample consisted of 165 TMD patients (65 males, 100 females; mean age: 32·55 ± 11·685years) with only disc displacement with reduction (RDC/TMD Axis I group IIa) and a control sample of 145 healthy subjects (65 males, 80 females; mean age: 31·24 ± 12·436 years) diagnosed with RDC/TMD Axis I group 0. A stepwise multiple logistic regression model was used to identify the significant correlation between occlusal features and disease. The odds ratio for disc displacement was 2·84 for absence of canine guidance, 2·14 for mediotrusive interference and 1·75 for retruded contact position (RCP)/maximum intercuspation (MI) slide ,2 mm. Other occlusal variables did not reveal to be statistically significant. The percentage of the total log likelihood for disc displacement explained by the significant occlusal factors was acceptable with a Nagelkerke's R2 = 0·124. The final model including the significant occlusal features revealed an optimal discriminant capacity to predict patients with disc displacement with a sensitivity of 63·6% or with a specificity of 64·8% for healthy subjects and an accuracy of 64·2%. Occlusal features showed a low predictive value for detecting disc displacement. Multifactorial complex pathologies such as TMD should be investigated using a multivariate statistical analysis; moreover, the future of aetiopathogenic research in this matter requires a multifactorial approach. [source] Bruxism physiology and pathology: an overview for clinicians,JOURNAL OF ORAL REHABILITATION, Issue 7 2008G. J. LAVIGNE Summary, Awake bruxism is defined as the awareness of jaw clenching. Its prevalence is reported to be 20% among the adult population. Awake bruxism is mainly associated with nervous tic and reactions to stress. The physiology and pathology of awake bruxism is unknown, although stress and anxiety are considered to be risk factors. During sleep, awareness of tooth grinding (as noted by sleep partner or family members) is reported by 8% of the population. Sleep bruxism is a behaviour that was recently classified as a ,sleep-related movement disorder'. There is limited evidence to support the role of occlusal factors in the aetiology of sleep bruxism. Recent publications suggest that sleep bruxism is secondary to sleep-related micro-arousals (defined by a rise in autonomic cardiac and respiratory activity that tends to be repeated 8,14 times per hour of sleep). The putative roles of hereditary (genetic) factors and of upper airway resistance in the genesis of rhythmic masticatory muscle activity and of sleep bruxism are under investigation. Moreover, rhythmic masticatory muscle activity in sleep bruxism peaks in the minutes before rapid eye movement sleep, which suggests that some mechanism related to sleep stage transitions exerts an influence on the motor neurons that facilitate the onset of sleep bruxism. Finally, it remains to be clarified when bruxism, as a behaviour found in an otherwise healthy population, becomes a disorder, i.e. associated with consequences (e.g. tooth damage, pain and social/marital conflict) requires intervention by a clinician. [source] Influence of occlusal vertical dimension on the masticatory performance during chewing with maxillary splintsJOURNAL OF ORAL REHABILITATION, Issue 8 2007L. W. OLTHOFF summary, Changing the occlusal vertical dimension is a common procedure in restorative dentistry, during treatment of patients with cranio-mandibular disorders, and during orthodontic and orthognathic treatment. The treatment may alter the length of the main jaw elevator muscles and the position of the mandibular head in the fossa temporalis. These changes may influence the bite forces that are generated during chewing and thus may affect the masticatory function. We measured the objective masticatory function, defined as masticatory performance, by determining an individual's capacity to pulverize a test food. The immediate influence of the increase in the occlusal vertical dimension on the masticatory performance was determined using three anatomical maxillary splints in a group of seven dentate subjects. The splints gave an increase in the occlusal vertical dimension of 2, 4 and 6 mm, respectively. Before we started the experiments the subjects practiced chewing with the splints during about 5 min. No significant differences were observed in masticatory performance among the conditions without and with the three splints. Thus, an increase in the occlusal vertical dimension up to 6 mm did not have a significant effect on the masticatory performance. Maxillary splints may be used to study the effect of occlusal factors on the chewing process by manipulating tooth shape and occlusal area of the splint. [source] Relationship between the prognosis of periodontitis and occlusal force during the maintenance phase , a cohort studyJOURNAL OF PERIODONTAL RESEARCH, Issue 5 2010N. Takeuchi Takeuchi N, Ekuni D, Yamamoto T, Morita M. Relationship between the prognosis of periodontitis and occlusal force during the maintenance phase , a cohort study. J Periodont Res 2010; 45: 612,617. © 2010 John Wiley & Sons A/S Background and Objective:, Few studies have longitudinally investigated the relationship between periodontal disease progression and occlusal factors in individual subjects during the maintenance phase of periodontal therapy. The aim of this cohort study was to investigate the relationship between biting ability and the progression of periodontal disease in the maintenance phase. Material and Methods:, A total of 194 patients were monitored for 3 years during the maintenance phase of periodontal therapy. The subjects with disease progression (Progress group) were defined based on the presence of , 2 teeth demonstrating a longitudinal loss of proximal attachment of , 3 mm or tooth-loss experience as a result of periodontal disease during the study period. The subjects with high occlusal force were diagnosed as men who showed an occlusal force of more than 500 N and women who showed an occlusal force of more than 370 N. The association between biting ability and the progression of periodontitis was investigated using logistic regression analysis. Results:, There were 83 subjects in the Progress group and 111 subjects in the Non-progress group. A backward, stepwise logistic regression model showed that the progression of periodontal disease was significantly associated with the presence of one or more teeth with a high clinical attachment level (CAL) of , 7 mm (odds ratio: 2.397; 95% confidence interval: 1.306,4.399) (,p = 0.005) and low occlusal force (odds ratio: 2.352; 95% confidence interval: 1.273,4.346) (,p = 0.006). Conclusion:, The presence of one or more teeth with a high CAL of , 7 mm and low occlusal force might be possible risk factors for periodontal progression in the maintenance phase of periodontal therapy. [source] Abfraction: separating fact from fictionAUSTRALIAN DENTAL JOURNAL, Issue 1 2009JA Michael Abstract Non-carious cervical lesions involve loss of hard tissue and, in some instances, restorative material at the cervical third of the crown and subjacent root surface, through processes unrelated to caries. These non-carious processes may include abrasion, corrosion and possibly abfraction, acting alone or in combination. Abfraction is thought to take place when excessive cyclic, non-axial tooth loading leads to cusp flexure and stress concentration in the vulnerable cervical region of teeth. Such stress is then believed to directly or indirectly contribute to the loss of cervical tooth substance. This article critically reviews the literature for and against the concept of abfraction. Although there is theoretical evidence in support of abfraction, predominantly from finite element analysis studies, caution is advised when interpreting results of these studies because of their limitations. In fact, there is only a small amount of experimental evidence for abfraction. Clinical studies have shown associations between abfraction lesions, bruxism and occlusal factors, such as premature contacts and wear facets, but these investigations do not confirm causal relationships. Importantly, abfraction lesions have not been reported in pre-contemporary populations. It is important that oral health professionals understand that abfraction is still a theoretical concept, as it is not backed up by appropriate clinical evidence. It is recommended that destructive, irreversible treatments aimed at treating so-called abfraction lesions, such as occlusal adjustment, be avoided. [source] Attrition, occlusion, (dys)function, and intervention: a systematic reviewCLINICAL ORAL IMPLANTS RESEARCH, Issue 2007Arie Van 't Spijker Abstract Objectives: Attrition and occlusal factors and masticatory function or dysfunction are thought to be related. This study aims to systematically review the literature on this topic with the emphasis to find evidence for occlusion-based treatment protocols for attrition. Materials and methods: Literature was searched using PubMed (1980 to 2/2006) and the Cochrane Library of Clinical Trials with the keywords ,tooth' and ,wear'. Five steps were followed. Exclusion was based on the following: (1) reviews, case-reports, studies on non-human tooth material, and studies not published in English and (2) historical or forensic studies. Included were (3) in vivo studies. Next, studies on (4) occlusal factors, function or dysfunction [temporomandibular disorders (TMD), bruxism], or intervention, and (5) attrition were included. Two investigators independently assessed the abstracts; measure of agreement was calculated using Cohen's ,; disagreement was resolved by discussion. Full-text articles were obtained and correlation between outcomes on occlusal factors, (dys)function, treatment, and attrition were retrieved. References in the papers included in the final analysis were cross-matched with the original list of references to add references that met the inclusion criteria. Results: The search procedure revealed 1289 references on tooth wear. The numbers of included studies after each step were (1) 345 (,=0.8), (2) 287 (,=0.87), (3) 174 (,=0.99), (4) 81 (,=0.71), and (5) 27 (,=0.68). Hand searches through the reference lists revealed six additional papers to be included. Analysis of the 33 included papers failed to find sound evidence for recommending a certain occlusion-based treatment protocol above another in the management of attrition. Conclusion: Some studies reported correlations between attrition and anterior spatial relationships. No studies were found suggesting that absent posterior support necessarily leads to increased attrition, though one study found that fewer number of teeth resulted in higher tooth wear index (on the remaining teeth). Attrition seems to be co-existent with self-reported bruxism. Reports on attrition and TMD signs and symptoms provide little understanding of the relationship between the two. [source] | ||||||||||