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Background: High occlusal forces in patients with untreated periodontitis may reflect occlusal trauma-associated periodontal conditions. Occlusal analysis using T-scan might provide the distribution of occlusal loading forces in periodontitis patients. The study aimed to evaluate the effect of occlusal trauma in periodontitis patients and occlusal calibration using a T-scan., Materials and Methods: A total of 30 periodontitis patients were recruited for the study. Patients were categorized into two groups: Group I: scaling and root planing followed by T-scan recording and no occlusal calibration; Group II: scaling and root planing followed by occlusal calibration using T-scan. Clinical parameters, orthopantomogram (OPG) and T-scan evaluation were evaluated at baseline, 3-month and 6-month intervals., Results: Significant improvements in clinical parameters were noted at different time intervals after occlusal calibration using T-scan. At 3-month intervals, mean pocket depth showed statistically significant difference among the test group in the right (upper and lower) and left lower quadrant at P = 0.01, 0.002 and 0.005, respectively. Mean clinical attachment level (CAL) showed statistically significant difference among the test group in the right upper, right lower and left lower quadrants at P = 0.02, 0.001 and 0.009, respectively, at 3 months. The comparison of the mean gingival index (GI) at 6 months showed statistically significant difference among test and control groups at 6 months in different study quadrants (P = 1 in right upper, 0.009 in right lower, <0.001 in left upper and <0.001 in left lower). Mean pocket depth at the 6-month follow-up showed statistically significant difference among the test group in all the study quadrants (P = <0.001 in right upper, <0.001 in right lower, 0.003 in left upper and 0.005 in left lower). Mean CAL showed statistically significant difference among the test group in all the study quadrants at 6-month intervals (P = 0.02 in right upper, <0.001 in right lower, 0.01 in left upper and 0.04 in left lower). The bone defect height showed a statistically significant difference only in the right upper quadrant among both the test groups at the 6-month follow-up (P = 0.02). Comparing the mean percentage of force on both sides of the jaw showed a statistically significant difference among the test group at 6 months (P = 0.001 on the left side and 0.001 on the right side)., Conclusion: The occlusal correction using T-scan showed a positive association between probing pocket depth (PPD) and CAL at different time intervals from baseline to 6 months when these parameters were compared after occlusal adjustments., (Copyright © 2024 Copyright: © 2024 Indian Journal of Dental Research.)

Background: Literature is scarce on malocclusion prevalence and orthodontic treatment need (OTN) in subjects with stage III-IV periodontitis. Study aims were to assess prevalence of primary and secondary malocclusions in subjects with stage III-IV periodontitis and OTN based on pathologic tooth migration (PTM) and occlusal trauma of anterior teeth (AT)., Subjects and Methods: One hundred and twenty-one subjects with stage III-IV periodontitis were examined. A comprehensive periodontal-orthodontic examination was performed. Exclusion criteria: age <30 years, removable prosthetics, uncontrolled diabetes, pregnancy/lactation, and oncologic disease., Results: Class II malocclusion was found in 49.6% (Class II div 1-20.7%, Class II div 2-9.9%, subdivision Class II-19.0%), Class I-31.4%, Class III-10.7%, no malocclusion-8.3% of subjects. PTM was observed in 74.4% of maxillary and 60.3% of mandibular AT. Spacing and extrusion were the main types of PTM of AT. Odds ratio for PTM of maxillary AT was 9.3 in cases with >30% of sites with clinical attachment loss ≥5 mm (P = 0.001). Spacing of maxillary AT was influenced by periodontitis, Class III malocclusion, and lost teeth. Tongue habit had impact on spacing of mandibular AT. Dental Health Component of Index of Orthodontic Treatment Need yielded that OTN was found in >50% and OTN due PTM, occlusal trauma and impaired function in 66.1% of subjects., Conclusions: The most prevalent malocclusion was Class II. Spacing and extrusion were prevalent types of PTM of AT. OTN was found in more than half of the subjects. The study highlights the need for preventive measures for PTM in subjects with stage III-IV periodontitis., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Orthodontic Society.)

Observational studies have indicated that crestal bone level changes at implants are typically associated with clinical signs of inflammation, but still mechanical overload has been described as possible factor leading to hard-tissue deficiencies at implant sites without mucosal inflammation. The aim of this paper was systematically review the literature regarding the possible effect of traumatic occlusal forces on the peri-implant bone levels. Literature search was conducted using PubMed, Scielo and Lilacs, including the following terms: oral OR dental AND implant$ AND (load OR overload OR excessive load OR force$ OR bruxism) AND (bone loss OR bone resorption OR implant failure$). Databases were searched for the past 10 years of publications, including: clinical human studies, either randomized or not, cohort studies, case control studies, case series and animal research. Exclusion criteria were review articles, guidelines and in vitro and in silico (finite element analysis) research, as well as retrospective studies. The PICO questions formulated was: "does traumatic occlusal forces lead to peri-implant bone loss?" The database searches as well as additional hand searching, resulted in 807 potentially relevant titles. After inclusion/exclusion criteria assessment 2 clinical and 4 animal studies were considered relevant to the topic. The included animal studies did not reveal an association between overload and peri-implant bone loss when lower overloads were applied, whereas in the presence of excessive overload it seemed to generate peri-implant bone loss, even in the absence of inflammation. The effect of traumatic occlusal forces in peri-implant bone loss is poorly reported and provides little evidence to support a cause-and-effect relationship in humans, considering the strength of a clinically relevant traumatic occlusal force.

Context: A better understanding of the relation between traumatic dental occlusion and periodontal changes is needed., Aims: This study aimed to evaluate the pattern of osteoclastic activity in the periodontal bone in front of the traumatic dental occlusion in rat molars., Patients and Methods: Traumatic dental occlusion (TO) was induced in twenty rats, which were sacrificed after periods of 2, 5, 7, and 14 days. Transversal histological sections of both jaws were stained with tartrate-resistant acid phosphatase and hematoxylin and eosin. Mann-Whitney U-test was used for group comparison, and Pearson's correlation test was applied for the number of osteoclasts and bone area (BA)., Results: Traumatic dental occlusion caused an increase in the number of osteoclasts in the bone of the upper and lower right first molar from days 2-5 to 2-14, respectively. In the TO groups, the number of osteoclasts on the lamina dura and in the center of the alveolar bone septum, respectively, increased almost 4-fold and 9-fold in the lower jaw; and 3-fold and 5-fold in the upper jaw, during all periods. In the TO groups, the BA of the alveolar bone septum was substantially reduced. There was a negative correlation between the number of osteoclasts and BA in both jaws during all experimental periods., Conclusions: Traumatic dental occlusion increases osteoclast activity in the alveolar lamina dura and in the center of alveolar bone and stimulates a higher degradation in the center of the alveolar bone septum.

Objective: To determine whether a unilateral increase or decrease in the bite affects the curvatures of the vertebral spine in rats., Methods: 25 male Sprague Dawley rats were included. Five animals received no alteration on their bite. Bite was increased on 10 animals and molar teeth were extracted on 10 other animals. Frontal and lateral radiographs were taken on days 0, 7, 14 and 21. Distances from landmarks to a true vertical line were measured on both radiographs., Results: Repeated measures analysis showed statistically significant differences between the amount of the curvature at the cervical and thoracic spines on frontal and lateral radiographs over time (P<0.05 and P<0.0001). One-way ANOVA computed significant differences (P<0.05) at D14 at the cervical and thoracic spines on both, increased and decreased vertical dimension., Conclusion: Alterations in the dental occlusion affects the normal curvatures of the vertebral spine in rats.

The main aim of this retrospective study was to describe clinical and histopathological findings in cats with mucogingival lesions developed at the contact point of the premolar and molar teeth of the opposite quadrant. Cases were retrieved following manual review of the medical records, dental records and photographic documentation of all feline dental patients visited in the period between February 2001 and August 2011. Cats showing different lesions at different times were calculated as multiple cases. A total of 27 cats (31 cases) with 44 lesions (26 proliferations [59%], 11 clefts [25%] and seven foveae [16%]) were included. Mean age at the time of the first visit was 6.6 years. The lesion object of the study was the main reason for presentation in only five cases (16%). Proliferations showed two different histopathological patterns and had characteristics in common with human oral pyogenic granuloma. Successful treatment was achieved in all cases by removing the occlusal contact by dental extraction or coronal reduction, possibly associated with lesion excision. This study underlines the need for a thorough oral examination and evaluation of dental occlusion in all patients. Causes for the development of traumatic occlusion may include an acquired overbite (possibly secondary to selective dental extraction), congenital or post-traumatic malocclusion, abnormal latero-lateral mobility of the mandible, occlusal drift of the premolar and molar teeth, and/or alveolar bone expansion., (© ISFM and AAFP 2014.)

Aim: This study evaluates the relationship between occlusal interferences and premature contacts and bruxism by determining the relationship between unassisted and assisted nonworking interferences., Materials and Methods: In this study, 60 subjects (14 males and 46 females) that consisted of 30 bruxers (7 males, 23 females) and 30 nonbruxers (7 males, 23 females) were selected after completion of a questionnaire based on the exclusion criteria. Occlusal interferences in the centric relation and eccentric movements in the two groups were evaluated and recorded. Data were analyzed by SPSS software (version 16) using the Chi-square and paired t-tests., Results: The results showed a statistically significant relationship between bruxism and nonworking interferences (p < 0.05). There was no statistically significant relationship in the centric relation and other eccentric movements (p > 0.05). The number of assisted nonworking occlusal contacts was more than unassisted nonworking occlusal contacts., Conclusion: According to the results of this study, there is a relationship between certain types of occlusal interferences (nonworking interferences) and bruxism. Hence, it would be useful to examine occlusal contacts in bruxing patients to eliminate probable causative or contributing occlusal factors. Both assisted and unassisted nonworking occlusal contacts should be evaluated., Clinical Implication: Bruxism is an oral habit that consists of involuntary rhythmic or spasmodic nonfunctional gnashing, grinding or teeth clenching, other than chewing movements by the mandible. Bruxism may lead to occlusal trauma, tooth wear, fracture of the teeth and fillings, and hypertrophy of the masticatory muscles. Treatment of bruxism needs a correct diagnosis. Therefore, it is useful to determine the relationship between occlusal interferences and bruxism in order to prevent its development by adjusting for these interferences.

In planning orthodontic cases that include extractions as an alternative to solve the problem of negative space discrepancy, the critical decision is to determine which teeth will be extracted. Several aspects must be considered, such as periodontal health, orthodontic mechanics, functional and esthetic alterations, and treatment stability. Despite controversies, extraction of teeth to solve dental crowding is a therapy that has been used for decades. Premolar extractions are the most common, but there are situations in which atypical extractions facilitate mechanics, preserve periodontal health and favor maintenance of the facial profile, which tends to unfavorably change due to facial changes with age. The extraction of a lower incisor, in selected cases, is an effective approach, and literature describes greater post-treatment stability when compared with premolar extractions. This article reports the clinical case of a patient with Angle Class I malocclusion and upper and lower anterior crowding, a balanced face and harmonious facial profile. The presence of gingival and bone recession limited large orthodontic movements. The molars and premolars were well occluded, and the discrepancy was mainly concentrated in the anterior region of the lower dental arch. The extraction of a lower incisor in the most ectopic position and with compromised periodontium, associated with interproximal stripping in the upper and lower arches, was the alternative of choice for this treatment, which restored function, providing improved periodontal health, maintained facial esthetics and allowed finishing with a stable and balanced occlusion. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO), as part of the requirements for obtaining the BBO Diplomate title.

The aim of this study is to present a classification with a clinical application for root resorption, so that diagnosis will be more objective and immediately linked to the source of the problem, leading the clinician to automatically develop the likely treatment plan with a precise prognosis. With this purpose, we suggest putting together all diagnosed dental resorptions into one of these four criteria: 1) Root resorption caused by cementoblast cell death, with preservation of the Malassez epithelial rests. 2) Root resorption by cementoblasts and Malassez epithelial rests death. 3) Dental resorption by odontoblasts cell death with preservation of pulp vitality. 4) Dental resorption by direct exposure of dentin to gingival connective tissue at the cementoenamel junction gaps.

Background: Traumatic dental injury (TDI) could have physical and psychosocial consequences for children. Thus, it is important to measure the impact of TDI on the quality of life of children (QoL). The aim of the present study was to investigate the association between treated/untreated TDI and the impact on the quality of life of 11-to-14-year-old Brazilian schoolchildren., Methods: A cross-sectional study was carried out involving 1612 male and female schoolchildren aged 11 to 14 years attending public and private elementary schools in the city of Belo Horizonte, Brazil. A multi-stage sampling technique was adopted to select the children. Three calibrated examiners used the Andreasen classification for the diagnosis of TDI. Oral health-related quality of life was assessed using the Brazilian version of the Child Perceptions Questionnaire (CPQ11-14) - Impact Short Form (ISF:16), composed of 16 items and self-administered by all children. Other oral conditions (dental caries and malocclusion) and the Social Vulnerability Index were determined and used as controlling variables., Results: Two hundred nineteen children were diagnosed with untreated TDI and 64 were diagnosed with treated TDI. There were no statistically significant associations between untreated or treated TDI and overall CPQ11-14 (Fisher = 0.368 and Fisher = 0.610, respectively). Children with an untreated TDI were 1.4-fold (95% CI = 1.1-2.1) more likely to report impact on the item "avoided smiling/laughing" than those without TDI, whereas children with a treated TDI were twofold (95% CI = 1.1-3.5) more likely to report impact on the item "other children asked questions" than those without TDI., Conclusions: Neither treated nor untreated TDI was associated with oral symptoms, functional limitations or emotional wellbeing. However, children with a TDI in the anterior teeth experienced a negative impact on social wellbeing, mainly with regard to avoiding smiling or laughing and being concerned about what other people may think or say.

Bruxism is the non-functional clenching or grinding of the teeth that may occur during sleep or, less commonly in the daytime in 5-20% of adults and about 30% of 56 year old children. Although research on bruxism is extensive, its etiology remains debatable. There is some literature to suggest that bruxism is correlated with temporomandibular disorders (TMDs) and malocclusion. The aim of this article is to present the course of this condition in a case of bruxism coupled with TMD with special emphasis on the importance of accurate diagnosis of maxillofacial pain. We also report an association between supernumerary teeth and TMDs that has not been reported earlier in the literature.

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.

Objectives: To test the hypothesis that experimentally created physiologically nonbalanced occlusion will not affect the thickness of the temporomandibular joint (TMJ) discs in rats., Material and Methods: Twenty-four 8-week-old Sprague-Dawley rats were equally divided into a control group that was left untreated and an experimental group where a nonbalanced occlusion was created. Elastic rubber bands, 1 mm in diameter, were inserted and 1 week later were replaced by plastic material between the first and the second molars of the left maxillary and the right mandibular dentitions to move the first molars about 0.8 mm mesially. This created and maintained a physiologically nonbalanced occlusion. The animals were euthanized 8 weeks later, and the TMJ disc thickness was measured on histologically prepared slices using an electronic meter. Two-way univariate analysis of variance was used to compare the groups (alpha level = .05)., Results: The intermediate zone was thicker in the experimental group than in the control group (P = .003), but no differences were found between groups regarding the anterior and posterior bands. There were no significant sex-related effects on this observation., Conclusion: The hypothesis is rejected. The results indicate that the intermediate zone of rat TMJ disc has the ability to adapt to the alteration of the space between condyle and fossa caused by occlusion changes. Further studies on larger groups that are followed for longer times are needed.

ABSTRACT The role of occlusion in periodontal disease has always been a challenging topic. A good understanding of the current status of the relationship of occlusion and periodontitis is of paramount importance in order for dental clinicians to provide adequate and comprehensive periodontal treatment in patients presenting with traumatic occlusion. This article reviews the literature regarding the relationship between occlusion and periodontitis and presents recommendations for clinical practice based on available evidence. Clinical cases illustrating the complexity of this relationship and their management are presented.

This report describes a rare situation in which external cervical resorption was associated with gingival enlargement (pyogenic granuloma) in the upper left central incisor (tooth 21) in a 28-year-old man. Tissue from the lesion was examined histopathologically; periodontal, endodontic and restorative treatments were performed; and the occlusal disharmony, which had resulted in traumatic occlusion, was corrected. Three years after these treatments, the gingiva is normal and healthy and there is no sign of recurrence of the pathologic enlargement. The patient"s periodontal condition is now routinely evaluated. In the presence of gingival enlargement resulting from inflammation, traumatic occlusion can cause progressive external root resorption.

Many different factors are known to cause and perpetuate the symptoms of temporomandibular disorders (TMD). However, the roles of parafunctional factors have not been clearly elucidated. We found one of these habits in the clinical setting. This parafunctional habit involves daily light touching of the upper and lower teeth, when the mouth is closed. We named this habit Teeth Contacting Habit (TCH). [OBJECTIVES] To investigate the following hypotheses: 1) TCH is associated with perpetuation of chronic pain of TMD patients; 2) TCH is associated with other behavioral factors. [METHODS] Two hundred and twenty-nine TMD outpatients with chronic pain were analyzed with multivariate logistic regression models. [RESULTS] TCH was found in 52.4% of patients. Patients with TCH and pain lasting for more than four months were less likely to experience improvements in pain at the first visit (OR = 1.944, p = 0.043). Other factors associated with TCH were as follows: unilateral chewing (OR = 2.802) and involvement in a precision job (OR = 2.195). [CONCLUSION] TCH can prolong TMD pain and is associated with other behavioral factors.

There is a growing interest in the relationship between occlusion and posture because of a greater incidence of neck and trunk pain in patients with occlusal dysfunction. The study was designed to verify whether an alteration of the spinal column alignment may be experimentally induced in rats as a consequence of altering dental occlusion and also to investigate whether the spinal column underwent any further changes when normal occlusion was then restored. Thirty rats were divided into two groups. Fifteen (15) rats (test group) wore an occlusal bite pad made of composite resin on the maxillary right first molar for a week (T1). The same rats wore a second composite bite pad for another week on the left first molar in order to rebalance dental occlusion (T2). Fifteen rats were included in an untreated control group. All the rats underwent total body radiographs at T0 (before the occlusal pad was placed), at T1 (one week after application of a resin occlusal bite pad on the maxillary left first molar) and at T2 (one week after application of a second resin occlusal bite pad on the maxillary right first molar). A scoliotic curve developed in all the test rats at T1. There were no alterations of spinal position observed in any of the control rats. Additionally, the spinal column returned to normal condition in 83% of the test rats when the balance in occlusal function was restored. The alignment of the spinal column seemed to be influenced by the dental occlusion.

An analysis of exclusively representative population-based studies on adults has shown that only few and inconsistent associations could be detected between malocclusions and clinical signs of temporomandibular disorders (TMD)--and none for functional occlusion factors (occlusal interferences, non-working side contacts, etc). The aim of this study was to analyze associations between morphologic occlusion as well as factors of functional occlusion and subjectively perceived symptoms of TMD--again on the basis of the population-based Study of Health in Pomerania (SHIP), providing a sample of 4310 subjects (out of 7008 subjects yielding a response rate of 68.8%) aged 20 to 81 years, and other international representative studies from the systematic review. Besides occlusal factors also parafunctions and socioeconomic status (SES) were taken into account (including age and sex). Multiple logistic regression analysis was used--adjusted for SES. In this study, none of the occlusal factors were significantly associated with the indication of more frequent subjective TMD symptoms. However, the parafunction "frequent clenching" was connected with subjective TMD symptoms (odds ratio = 3.4). Compared with other population-based studies few and (across studies) inconsistent associations between malocclusions and subjective TMD symptoms could be ascertained. No significant associations of factors of functional occlusion with TMD symptoms were identifiable.

The aim of the present study was to investigate the relationship between noncarious cervical lesions (NCCL) and dental premature contacts (PC). Following examination of 1,974 teeth from 77 patients referred to the Department of Oral Medicine, Faculty of Dentistry, Mashad University of Medical Science, Iran, a total of 167 teeth were identified to have the criteria set for noncarious cervical lesions (regarded as NCCL group). Also, 167 teeth exhibiting no such lesions were selected randomly from the same population (regarded as control group). The results indicated that within the NCCL group, the frequency of noncarious cervical lesions differed significantly among the various teeth; the first premolar teeth showed the greatest number of cervical lesions, followed by the canine teeth, and the second molar teeth had the least number of lesions. A similar trend was detected in the total number of premature contacts among the seven types of teeth. The results revealed a highly significant and positive correlation between the incidence of NCCL and the PC. The NCCL group and the control group differed significantly in the number of premature contacts in centric relation (CR) and working side, but not in balancing and protrusion.

The aim of the present study was to establish whether the early signs of various orofacial dysfunctions, malocclusions, or occlusal interferences can predict the development of temporomandibular dysfunction (TMD) in young adults. Forty-eight subjects referred for speech therapy and 49 controls participated in all four stages of this longitudinal study. The subjects were examined at the ages of 7, 10, 15, and 19 years. The phoniatrician diagnosed errors in place of articulation and problems in the movement and co-ordination of the speech articulators. Occlusion, TMD signs (palpatory tenderness of the masticatory muscles, and of temporomandibular joints (TMJ), jaw deviation on opening, and clicking), mandibular movement capacity and occlusal interferences were registered by the orthodontist. Multiple logistic regression models were applied in order to evaluate whether single signs of TMD at the age of 19 years were related to previous/present malocclusions or interferences, to misarticulations of speech, problems in oral motor skills, or other signs of TMD. The effect of gender was also considered. The results showed that excessive overjet was the only variable which seemed to consistently increase the risk of TMD. In addition, girls seemed to be more prone to the development of TMD than boys. Although, during growth, there were both local and central factors associated occasionally with TMD development, the predictive value of those variables in the estimation of the individual risk of TMD was rather small.

Background: The aim of this study was to investigate the existence of associations between bruxism and psychic and occlusal factors., Methods: Participants in this study (n=85) were recruited from the Section of Odontostomatology, Deparent of Neuroscience, University of Pisa, Italy. They were split into two groups, bruxers (n=34) and non-bruxers (n=51), on the basis of the presence of both clinical and anamnestical indicators of bruxim. All participants were administered two self-reported validated questionnaires to evaluate (MOODS-SR) and panic-agoraphobic (PAS-SR) spetra. A number of occlusal variables (deep-bite: cross-bite, open-bite, mediotrusive and laterotrusive interferences, slide RCP-ICP, laterotrutsive guides, canine and molar classes) were also recorded., Results: With regards to occlusal factors, the only association was revealed between bruxism mediotrusive interferences (p < 0.05). As for psychiatric investigation, significant differences between bruxers and controls emerged for the presence of both depressive (p < 0.01) and manic symptoms (p < 0.01) in MOODS-SR, and for stress sensitivity (p < 0.01), anxious expectation (p < 0.05), and reassurance sensitivity symptoms (p < 0.05) in PAS-SR. In particular, both mood (p < 0.01) and panic-agoraphobic (p < 0.05) spectra symptoms seem to differentiate bruxers from controls in males, while in females strong differences emerged for stress sensitivity symptoms (p < 0.05)., Conclusions: It can be confirmed that certain psychic traits are present in bruxers, while occlusal factors are not useful parameters to discern bruxers from non-bruxers.

This study assessed the maxillomandibular relationship in temporomandibular disorders (TMD) patients, before and after short-term, flat plane bite plate therapy. It was of interest to determine the incidence and degree of mandibular deviation in a group of TMD patients and whether the mandible would shift to the midline and consequently affect reported symptoms. Seventeen female and three male subjects (age range 19-60) were included in the study. Thirteen subjects were diagnosed with myofascial pain while seven were diagnosed as exhibiting disk displacement with reduction (Research Diagnostic Criteria). After taking impressions for these subjects, casts were fabricated and mounted. Maxillomandibular relationship was evaluated by the Denar Centric Check system (Anaheim, CA). The maxillary and mandibular labial frena were used as a reference to evaluate mandibular shift. Symptom questionnaires were used to assess temporomandibular joint pain and clicking. All subjects exhibited deviation (12 subjects to the right and 8 subjects to the left) prior to bite plate therapy. After flat plane bite plate therapy, the mandibular position of all subjects shifted toward the labial frenum midline position. Based on the Binomial test, the shift was significant (p < 0.001). Measurements on the Centric Check system showed a significant movement of both condyles in the anterio-posterior plane as well as the vertical plane. There was also significant reduction in TMJ pain and clicking (p < 0.01). The results support the hypothesis that the balanced position of the mandible is with frena aligned. When occlusal obstructions are eliminated, the mandible will drift to this position.

This article describes the case of a 78-year-old patient whose mandibular fracture was treated with miniplate osteosynthesis. After initial treatment, panoramic radiography revealed a fracture of the miniplate, and at follow-up, a loosening of the replacement plate. For the dental practitioner, this clinical case highlights the importance of panoramic radiography and occlusal analysis and stabilization for diagnosis of mandibular fracture, evaluation of miniplate fracture and treatment, especially in the absence of trauma.

Hearing problems such as hearing loss and susurrus aurium are said to improve with occlusal treatment, but few objective clinical reports have been published in the dental field. We looked at the effect of occlusal treatment and chewing instruction on hearing ability in five patients who had an occlusal disorder and the unilateral chewing habit. The following results were obtained: 1. Unilateral chewing due to occlusal disorder may cause differences in hearing ability between the right and left sides (Cases 1, 2 and 3). 2. A reduction in the vertical dimension of occlusion is considered to be one of the factors that cause a decrease in hearing ability (Cases 4 and 5). 3. In all cases, occlusal treatment and chewing instruction lead to a improvement in hearing and to equalizing of hearing ability between low and high frequencies. These clinical findings indicate that there is a relationship between changes in hearing ability and oral function.

The purpose of this article is to review the clinical features, diagnosis and management of the cracked tooth syndrome (CTS). The condition refers to an incomplete fracture of a vital posterior tooth that occasionally extends into the pulp. A lack of awareness of the condition coupled with its varied clinical features can make diagnosis of CTS difficult. Common symptoms include an uncomfortable sensation or pain from a tooth that occurs while chewing hard foods and which ceases when the pressure is withdrawn. The patient is often unable to identify the offending tooth or quadrant involved, and may report a history of numerous dental procedures with unsatisfactory results. Successful diagnosis and management requires an awareness of the existence of CTS and the appropriate diagnostic tests. Management options depend on the nature of the symptoms and extent of the lesion. These options include routine monitoring, occlusal adjustments, placement of a cast restoration and endodontic treatment. A decision flowchart indicating the treatment options available to the dental practitioner is presented.

The purpose of this study was to assess the tissue alterations in the temporomandibular joint (TMJ) of the New Zealand White rabbit (Oryctolagus cuniculus L.), after a unilateral occlusal interference insertion on the animal's right side back teeth. A total of 36 animals were used, thirty of which belonged to the experimental group and six to the control group. We established three experimental periods: 24 hours, three days and seven days. The control group animals were divided two by two; each pair followed the same experimental periods of the former one. The experimental group animals were submitted to the use of a 0.3 mm thick metallic cap with a visor. All animals were euthanized, and the TMJs were removed. Using a microscope for examination we observed, in all experimental periods, the presence of intra-articular hemorrhage in the supra- and infra-disk compartments as well as in the retro-disk zone. There were no inflammatory cells detected. The thickness of the condylar fibrocartilage presented significant alterations among the animals of the three experimental groups. In the left TMJs no inflammatory cells were detected. The results suggest that the insertion of a unilateral occlusal interference in rabbit back teeth does not cause any inflammatory intra-articular process within seven days; however, it does cause bilateral intra-articular hemorrhage and a larger compression of the condylar fibrocartilage in the joint opposite the side where the interference is placed. We also concluded that, in order to do research on the temporomandibular joint using animals, it is necessary have an independent (or separate) group of animals as controls.

The purpose of this article is to review the literature on the relationship between occlusal discrepancies and temporomandibular disorders (TMD) and to summarize the guidelines of treating TMD by prosthetic rehabilitation. To date, the relationship between occlusal condition and TMD has not been confirmed, although there is a current trend toward making a weak correlation between occlusal interference and TMD. Furthermore, several types of occlusal discrepancies have been considered as variable features of the norm. But unstable occlusion in the intercuspal position may cause TMD. In cases of restored dentition, the problem is probably different and iatrogenic TMD are not rare. Namely, malformed occlusal surfaces, defects in anterior guidance, occlusal curvature, and vertical dimension may lead to some TMD trouble. According to these recent concepts the treatment modalities of TMD have been changed. Conservative treatments such as counseling, behavioral modification, physical therapy, pharmacotherapy, and interocclusal appliances should be the first choice, and treatments that lead to drastic changes of occlusion are not recommended.

Temporomandibular disorders (TMD) which comprise myogenic and arthralgic components have been reported to predispose subjects to headache and facial pain. The aim of this study was to evaluate the role of these components in patients with facial pain and to investigate the influence of treatment of TMD on pain of these patients. The subject group consisted of 25 patients suffering from facial pain. The clinical stomatognathic examination was performed before conservative treatment of TMD, and one-two weeks, three months and one year after treatment. The severity of TMD was assessed using the anamnestic (AI) and clinical dysfunction (DI) indices of Helkimo. The intensity of pain was evaluated on a numerical rating scale (NRS). According to clinical findings the patients were classified to following diagnostic subgroups: TMD myo (mainly myogenic), TMD arthro (mainly arthrogenous) and TMD comb (both myogenic and arthrogenous components involved). Fifteen patients were classified in the TMD myo group, nine in the TMD comb group and one in the TMD arthro group. The DI index decreased significantly one-two weeks after treatment and remained at this level at three month and one year follow-up examinations. At the first examination the TMD myo group had the highest level of NRS index, which decreased significantly during the time of follow-up, while no significant changes were found in other groups. Bruxism reported by the patient had a positive correlation with the amount of painful muscles on the right side at first examination. The results show that facial pain combined with TMD may be mostly of myogenic origin, and myogenic pain seems to have most favorable response to conservative treatment of TMD.

This work presents a case report of a woman, aged 62, who presented with signs and symptoms of temporomandibular disorder (TMD). The patient reported pain in the masticatory system and examination showed a reduction in the occlusal vertical dimension (OVD). She was treated with complete dentures incorporating a modification to the posterior regions developed by the authors and which were termed "sliding plates." Through analysis of photographs taken of the patient prior to the extraction of the patient's natural dentition, sliding plates were utilized to reestablish the OVD. The sliding plates also allowed for unrestricted eccentric mandibular movements, thereby accelerating the neuromuscular deprogramming and making it possible for the mandible to adopt a more physiologic position. The dentures reduced the pain and were well-accepted by the patient. Therefore, sliding plates may be of great benefit to completely edentulous patients with painful symptoms that result from alterations in the OVD and inappropriate condylar positioning.

Recent studies and literature reviews of temporomandibular disorders (TMD) do not strongly support the role of occlusal etiologic factors. For this paper we collected and classified studies dealing with occlusion as a contributing factor to TMD through reviews, and discussions of these difficulties and possible solutions. Related articles from 275 papers covering nearly the past twenty years were selected from a prosthetic point of view and reviewed. The validity and reliability of occlusal examinations, however, are questionable since the epidemiological studies dealt with numerous varied subjects. Although occlusal relationships, such as overbite, non-working side interferences, and discrepancy between the intercuspal position and the retruded contact position, have often been considered as contributing factors of TMD, there is no consistency among even those studies that support such an occlusal factor. A project should be initiated to create a revised, precise and practical method to determine the occlusal contact and to categorize an occlusal contact scheme. To detect whether the patients' occlusal scheme works traumatically or not should be an important part of the occlusal examination. That is, the frequency and duration of tooth contact on the occlusal scheme should be studied.

In 13 healthy subjects (eight men and five women, mean age, 22 years), an aluminum intercuspal interference (height, 0.25 mm) was placed on the maxillary right first premolar to study its effect on the contractile symmetry of the right and left masseter and anterior temporalis muscles when measured through a Percentage Overlapping Coefficient (POC), derived from surface electromyographic recordings of maximum voluntary teeth clenching. Additionally, and to estimate the potential of the experimental intercuspal interference to induce lateral displacement of the mandible, a Torque Coefficient (TC) was derived from surface electromyographic recordings. The conclusion was that the experimental occlusal interference gave rise to asymmetric contractile activity in the studied mandibular elevator muscles as well as a potential to displace the mandible in a lateral direction.

Erosion and abrasion have been widely reported as causes of non-carious cervical lesions (NCCL). However, more recently, tooth flexure has been implicated in the formation of these lesions generating renewed interest in the pathogenesis of the non-carious loss of cervical tooth substance. This paper considers the causes of erosion and abrasion, related to modern lifestyles, and reviews the literature concerning tooth flexure as a cause of NCCL. A description of different types of NCCL is given, as an aid to determining the aetiology, yet at the same time accepting that the causation and pathogenesis of NCCL is probably multi-factorial resulting in many different clinical presentations. Consideration is given to the indications for treatment of NCCL and to the selection of materials for restoring such defects.

One of the roadblocks to success in treating temporomandibular joint dysfunction (TMD) patients is an accurate diagnosis. The terms "TMJ" or "TMD" are not specific enough to provide definitive treatment. Initially the disorder must be classified as a muscular or an internal derangement problem. Once accomplished, the further diagnostic breakdown of the problem will prepare the patient and the doctor for the scope of treatment necessary and the prognosis. This lack of a specific diagnosis can lead to inappropriate treatment and inadequate communication among clinical dentists, academia and patients. Our patients and the profession will continue to suffer until a single diagnostic system is universally agreed upon and utilized.

When the signs and symptoms of temporomandibular joint disorders (TMD) are present, the possibility that occlusal position and mandibular movements are changed is considerable. Accordingly, the presence of occlusal interferences may be misjudged. It is therefore reasonable to consider that occlusal conditions should be examined just after the relief of symptoms. A comparison of occlusal condition in 45 patients with eminence clicking with a group of 60 asymptomatic controls was made. An occlusal examination was administered to the patient group just after the relief of clicking using bite plane therapy alone. The number of occlusal teeth in ICP (intercuspal position) for the patient group was significantly lower than for the controls, and the frequency of no contact of canines on the working side in the patient group was higher than that in the control group. This suggested that in order to avoid the recurrence of eminence clicking, efforts should be made to raise the number of contact teeth in ICP and to make canines on the working side come into contact.

The aim of the study was to compare the presence of oral tori and parafunctional activity (clenching, grinding teeth and/or bruxism) between temporomandibular disorder (TMD) patients and control subjects. Fifty-nine TMD and 353 control subjects were included. The groups were similar in sex and age distribution. There was no significant difference in prevalence of torus palatinus (TP) between TMD and control group (P = 0.2), while torus mandibularis (TM) was more common in TMD than in control group (P < 0.0005). Parafunctional habit was more common in TMD patients than in the control group (P < 0.0005). There was no significant association between size of TM and Helkimo's dysfunction index (P = 0.4). The results show that the prevalence of TM and parafunctional activity was higher in TMD than control patients. TM might be useful as an indicator of increased risk of TMD in some patients.

The purpose of this study is to assess what impact shortening disclusion time to less than .5 seconds during right and left mandibular excursions has on myofascial pain(s) symptoms present in a dental student population. Twenty-five dental students, who exhibited symptomatology consistent with myofascial pains patient, were divided into a treatment, control, and an untreated group. They participated in an occlusal adjustment study which measured changes in disclusion time, as well as, myofascial pains muscular symptom remissions resultant from treatment. The treated group of ten subjects received ICAGD occlusal adjustments to shorten their disclusion time to less than .5 seconds per mandibular excursion. The goal of this therapy was to totally disclude the posterior teeth in a measurable time frame of .5 seconds or less. The control group of eight subjects received mock ICAGD with tooth polishing. The goal of this therapy was to simulate ICAGD adjustments for possible placebo effect on symptom remissions. The untreated group had their disclusion times measured but received no treatment to adjust, or to simulate adjustment to their occlusion. The goal of analyzing an untreated group was to attempt to show that mock treatment (performed on the control subjects), or no treatment (performed on the untreated subjects), resulted in no measurable change in the disclusion time in either of these two subject groups. Each subject was recalled for disclusion time measurement four to five times in a one-year period of observation, at which time, they were required to report their myofascial pains symptom status by answering an ordinal scale questionnaire. The results suggest that shortening disclusion time to less than .5 seconds per mandibular excursion can induce remissions of many muscular myofascial pains symptoms. Additionally, mock ICAGD occlusal adjustments did not appear to be a factor in the control subjects treatment response, as this group showed no statistically significant symptom remissions.

The purpose of this study is to investigate the effects of orthodontic treatment on centric discrepancy. Thirty-six orthodontic patients who had been treated with an edgewise appliance were selected for this study while 30 persons who had no history of orthodontic treatment were used as a control group. After recording centric relation using a leaf gauge, centric prematurity, and centric slide were compared using a SAM2 articulator and mandibular position indicator. Results indicated that the number of subjects with one prematurity was significantly greater in the control group (86.7%); however, the number of subjects with two or more prematurities was greater in the orthodontic treatment group (41.6%). The orthodontic treatment group showed more bilateral prematurities. There were no differences between the two groups with regard to the teeth involved in centric prematurities. Just considering the anatomic portion of teeth, centric prematurities were significantly associated with the buccal incline of the maxillary palatal cusp. There were no significant differences in the amount or direction of centric slide between the orthodontic and control groups. This study indicates that orthodontic treatment does not generally result in an increase in centric discrepancy.

In the literatures, the relationship between missing teeth or malocclusion and the symptoms of temporomandibular joint disorder such as frequent headaches, earaches, sinus pain, and jaw pain, has been documented. However, there were no specific details as to which teeth were missing to cause these symptoms. In this project the relationship between missing first molars in adult female subjects to the previously mentioned symptoms was studied using one group of 65 subjects with missing one, two, three, or four first molars and a control group of 67 subjects with no missing first molars. The study revealed a significant relationship of missing first molar(s) and the occurrence of headaches, earaches, sinus pain, and jaw pain.

This study was conducted in order to determine the influence of variation in the occlusal contacts on electromyographic (EMG) cervical activity in 20 patients with myogenic cranio-cervical-mandibular dysfunction. EMG recordings during maximal voluntary clenching were performed by placing surface electrodes on the left sternocleidomastoid and upper trapezius muscles in the following conditions: intercuspal position; edge to edge left laterotrusive contacts (ipsilateral); edge to edge right laterotrusive contacts (contralateral); edge to edge protrusive contacts; and retrusive occlusal contacts. A significant higher EMG activity was recorded in both muscles during maximal voluntary clenching in retrusive occlusal contact position, whereas no significant differences in EMG activity were observed between intercuspal position, ipsilateral, contralateral and protrusive contact positions. The EMG pattern observed suggests that a more frequent intensity and duration of tooth clenching in retrusive occlusal contact position could result in more clinical symptomatology in these cervical muscles in patients with myogenic cranio-cervical-mandibular dysfunction.

The aetiology of non-carious cervical lesions is discussed. These have been variously described as 'abrasion', 'erosion', 'abrasion/erosion', and 'idiopathic cervical'. However, many lesions do not fit the classical appearance or location of an erosive and/or abrasive origin, and there is increasing interest in the possible role of occlusal stress in their aetiology. Non-carious cervical lesions often require restoration, and there are essentially three options using tooth-coloured materials: a restorative glass ionomer cement, a liner/base glass ionomer cement overlayed with a resin composite, or a resin composite bonded by an enamel/dentine-adhesive. The materials and techniques used in these options are discussed, indicating their advantages and disadvantages. Results of available clinical trials of these systems are given, and the link with the stress theory of cervical tooth loss is described. The preferred restorative approaches in order are: resin-modified restorative glass ionomer; resin-modified liner/base glass ionomer with a microfine resin composite overlay; enamel/dentine bonding agent with a microfine resin composite.

A recall study of 102 myofascial pain dysfunction syndrome-temporomandibular disorder (MPDS-TMD) patients, treated with disclusion time reduction therapy from 1983 to 1991, was undertaken to determine the long-term results of this treatment on symptom reductions. The patients were asked to fill out a symptom questionnaire which used ordinal number scales to determine their disease status (frequency and intensity of muscular, joint and dysfunctional symptoms; frequency of medication and appliance use) before and after they were treated with disclusion time reduction. The statistical results indicate that discluson time reduction therapy is a highly effective treatment regimen for MPDS and that it has lasting effects on symptom reduction. In addition, the results of this recall study indicate that occlusion, and more specifically, lengthy pretreatment disclusion time, does play a primary role in the symptomatology, and most probably, in the etiology of MPDS and TMD.

Magnetic resonance imaging (MRI) is excellent for visualizing soft tissues of the temporomandibular joint (TMJ) . Because it has no harmful effects, it can be used in asymptomatic subjects. MRI and clinical findings relating to TMJs were correlated with findings relating to occlusion in 20 medical and dental students (13 women, 7 men) who volunteered to participate in our study. Subjects with clinically evident joint signs such as clicking, crepitation or tenderness on palpation also exhibited pathologic MRI findings, especially in regards to configuration, position and function of the disk, and, often, disturbances of occlusal relationships between the upper and lower teeth.

Dentists treating craniomandibular dysfunction frequently encounter pain and dysfunction in seemingly unrelated distal areas of the body. This is a study using manual palpation to demonstrate a change in distal muscle pain response caused by altering an apparent noxious tooth contact. Forty-four (n = 44) patients with a defined muscle involvement were selected for this study. After isolating one tooth and the single contact that influenced the muscles under observation, one or two slight alterations were made to the contact to redirect the occlusal force in all but the four control subjects. Thirty-eight (n = 38) patients showed marked relief in tenderness to palpation following minute tooth alteration in the muscles being observed. Two (n = 2) showed slight improvement. No significant change in pain to palpation was noted in the control group (n = 4). The results suggest that altering an apparent noxious occlusal contact has a direct influence on muscles in other parts of the body.