Presence Of Occlusal Interference Research Articles

Clinical and Radiographical Measurements of Supraeruption and Occlusal Interferences in Unopposed Posterior Teeth

This study compared the supraeruption of teeth for study casts (SCs) and panoramic radiographs (PRs) and its relation to tooth type, arch, facial sides, presence of occlusal interferences, and type of tooth movements. A total of 65 patients with their SCs and PRs were recruited. Supraerupted tooth type, arches, sides involved, and the presence of occlusal interferences were recorded. The SCs for supraerupted teeth were photographed, and supraeruption from PRs was recorded from the patients' files. The values were transferred to a software program and assessed. The highest frequency was observed among the younger-age group and molars in both arches. Working side (WS) and retruded cuspal position (RCP) interferences were recorded the highest. Supraeruption values of 0.7-1.2 mm accounted for 47.5% (38) of the total. Tilting and tipping of teeth were the highest, followed by buccolingual displacement. Kappa tests showed good intraexaminer reliability and Bland-Altman plot showed 95% confidence interval band. No significant differences were observed in the supraeruption values between the type of tooth among different subgroups of SCs and PRs. Significant differences were recorded between the types and sites of teeth, with a higher ratio observed in molar teeth, mandibular arch, and young age group. RCP and WS were the most recorded occlusal interferences and buccolingual displacement, and tilting and tipping were the most noticeable occlusal tooth movements. Diagnosis and measurements of supraeruption are essential, useful, and significant steps before treatments for replacement of missing tooth/teeth as well as corrections of occlusal interferences during different mandibular movements.

Pista direta planas para tratamento de mordida cruzada anterior funcional – relato de caso

Anterior crossbite is a malocclusion frequently found in deciduous and mixed dentitions, it can be classified as dental, skeletal or functional. This last one has a favorable prognosis when the treatment occurs in early stages. Considering this, Planas direct tracks have been showing to be an effective and less invasive alternative when few dental elements are involved. This paper presents a clinical case of a 6-year-old patient with functional unilateral anterior crossbite whose differentiated diagnosis and early intervention allowed a successful treatment. By manipulating the jaw and positioning the condyles in centric relation (CR), the presence of occlusal interference between the upper and lower deciduous canines on the right side was noticed, which are the causes of mandible anterior displacement with occlusion in MIH. For correction, Planas direct track therapy was used on the upper right canine with composite resin followed by slight wear on the lower right canine. The premature contacts were eliminated, creating an inclined plane of approximately 45 degrees on the palatal face of the upper canine and a slight occlusal adjustment on the incisal surface of the lower right canine. The use of this technique allowed the correction of the functional anterior crossbite immediately after the removal of the occlusal interference. This case shows that the early treatment of crossbites increases the chances of a successful rehabilitation of stomatognathic system. The use of Planas direct tracks proved to be an effective, low-cost, and easy to implement alternative for functional crossbites correction.

Measurement of Spee curve in individuals with temporomandibular disorders: a cross-sectional study

Several factors are cited as capable to influence the development of Temporomandibular Disorders (TMD), among them, the psychological, systemic, genetic, and occlusal factors. The curve of Spee is the factor directly related to the TMJ. However, the combination of variations in amplitude, and the presence of signs and symptoms of TMD have not been investigated. Objective: The aim of this study was to measure the curve of Spee in patients with TMD, through the use of study models, comparing these values with the different clinical and symptomatic presentations of such individuals. We evaluated 198 models of patients treated at the care service for patients with TMD at UFJF. The maximum depth of the curve was determined by the sum of the distances between the lowest part of the buccal cusp of the posterior teeth of each hemiarch to a reference plane, using a caliper to measure. The following factors were considered: gender, presence of myalgia (temporal, masseter, medial pterygoid, lateral and sternocleidomastoid muscles) and TMJ arthralgia, and the presence of occlusal interferences and parafunctional habit of bruxism. For statistical analysis, we used T-test and ANOVA test with a significance level of 5%. Conclusion: There was a statistically significant association between the presence of occlusal interferences and changes in the curve (p = 0.01). There was no association between the following factors: the presence of myalgia and/or arthralgia, gender, achievement of bruxism, and the type of TMD presented with changes in the Spee curve.

Measurement of Spee curve in individuals with temporomandibular disorders: a cross-sectional study

Several factors are cited as capable to influence the development of Temporomandibular Disorders (TMD), among them, the psychological, systemic, genetic, and occlusal factors. The curve of Spee is the factor directly related to the TMJ. However, the combination of variations in amplitude, and the presence of signs and symptoms of TMD have not been investigated. Objective: The aim of this study was to measure the curve of Spee in patients with TMD, through the use of study models, comparing these values with the different clinical and symptomatic presentations of such individuals. We evaluated 198 models of patients treated at the care service for patients with TMD at UFJF. The maximum depth of the curve was determined by the sum of the distances between the lowest part of the buccal cusp of the posterior teeth of each hemiarch to a reference plane, using a caliper to measure. The following factors were considered: gender, presence of myalgia (temporal, masseter, medial pterygoid, lateral and sternocleidomastoid muscles) and TMJ arthralgia, and the presence of occlusal interferences and parafunctional habit of bruxism. For statistical analysis, we used T-test and ANOVA test with a significance level of 5%. Conclusion: There was a statistically significant association between the presence of occlusal interferences and changes in the curve (p = 0.01). There was no association between the following factors: the presence of myalgia and/or arthralgia, gender, achievement of bruxism, and the type of TMD presented with changes in the Spee curve.

Postero-inferior condylar movement induced by artificial occlusal interference on the balancing side during fictive mastication in rabbits

ObjectiveTooth contact does not occur on the balancing side during mastication. Hence, it is possible that the presence of occlusal interference on the balancing side causes mandibular rotation followed by atypical condylar movement because the jaw-closing muscle activity on the working side is greater than on the balancing side. The aim of the present study was to investigate the relationship between occlusal contact on the balancing side and condylar movement during mastication. MethodsEMG activity of the masseter (MS), lateral pterygoid (LP) and digastric (DG) muscles and jaw movements were recorded. Condylar movements in the sagittal plane were recorded using a high speed charge-coupled device (CCD) camera. Incisal point movements were recorded using a magnet on the mentum and a magnetometric sensor on the nasal bone. A removable biting plate was used to introduce an artificial occlusal interference on the balancing side. ResultsNine of the 10 rabbits showed large postero-inferior condylar movement (Pi-Cm) when a biting plate was applied on the balancing side. Five rabbits showed very small Pi-Cm when a biting plate was applied on the balancing side. In the small Pi-Cm group, MS activity decreased markedly and LP and DG transient activity appeared in the early occlusal phase in the presence of the biting plate. ConclusionInterference on the balancing side always caused Pi-Cm on the ipsilateral side during mastication. However, the degree of Pi-Cm was often decreased by a jaw opening reflex response.

The prevalence of craniomandibular disorders and occlusal disharmonies in the identical twins

Objective. The aim of this study was to determine the prevalence of craniomandibular disorders (CMD) and occlusal disharmony in identical twins. Methods. Craniomandibular and occlusal disharmony, in a population of 30 pairs of identical twins, aged 20-40 years, with the same gender, were determined by history and functional analysis. The final evaluation was performed using estimation of dysfunction index (Di) and occlusal index (Oi). Results. In study sample 23 twins (38.3%) had a sign of craniomandibular dysfunction, and 33 (55%) of twins had occlusal abnormalities, such as incompatibility of mid dental arches with intercuspal relation -ICP, lack of contact with the antagonists in the ICP, the presence of occlusal interference or loss of teeth. The analysis of the representation of certain craniomandibular signs in 23 patients in whom the index dysfunction (Di) by Helkimo was greater than zero revailed the prevailing disturbed kinetics of the mandible (44.0%), the sound in the TMJ with movements of the mandible (22.0%) and deviation when opening the mouth (22.0%). Positive occlusal index was in 33 (55%) patients, of whom 24 (40%) had mild occlusal disharmony (Oi I = 1), and 9 (15%) patients had the pronounced occlusal discrepancies (Oi II = 2). Conclusion. The comparative analysis of craniomandibular disorders and occlusal status, in identical twins, has shown that occlusal factors play an important role in the etiology of craniomandibular dysfunction.

Analyze the presence of occlusal interference and non-carious cervical lesions

Analyze the presence of occlusal interference and non-carious cervical lesions

Occlusal scheme in a group of Thais

PURPOSETo study the distribution of various occlusal schemes as well as associated static occlusal relationship among Thais.MATERIALS AND METHODSThe subjects' occlusal schemes on the left and right sides were classified as canine protected occlusion, group function, or unclassified according to the definition from Glossary of Prosthodontic Terms (8th edition). In addition, the presence of occlusal interferences during mandibular excursions were recorded. The measurement of the horizontal overlap and vertical overlap was also performed. Chi-square, One-way ANAVA and Mann-Whitney U statistical tests were used with level of significance set at P=.05.RESULTSTotal of 104 subjects were included in this study. The ratio for male to female was 1.8 to 1. Average age of the population was 25.01±6.87 years old. The mean vertical overlap and horizontal overlap were 1.94±1.20 and 2.41±1.32 mm respectively. The majority of the populations (68.3%) possessed group function occlusal scheme. For the remaining, 17.3% possess canine protected occlusion and 12.5% possess combination of both occlusal schemes. We also found that occlusal interference was presented in 20.2% of the population. The most common was protrusive interference (57.14%), the second was balancing interference (38.1%) and the third was working interference (4.1%).CONCLUSIONAmong Thais, the most common occlusal scheme was group function, however there were no significant occlusal factors related to any particular occlusal scheme.

"Electromyographic pattern of masticatory muscles in altered dentition" Part II.

Aim:The aim of this study is to show that a change in occlusal contacting pattern of tooth has definite influence over the behavior of orofacial musculature, resulting deleterious effect on it. Keeping this in view, the electromyographic (EMG) activity of temporalis and masseter muscles in rest position of mandible, maximum clenching and chewing, was studied in total 24 subjects--14 subjects with normal occlusion and rest 10 with normal occlusion and one tooth carious which was prepared to receive an inlay with high point. This high point or occlusal interference was introduced intentionally to have a change in occlusion or “altered dentition”. The subjects were all male medical volunteers with average age group of 20 years. A particular variety of chewing substance – chewing gum was used in this study. No EMG activity was detected in the rest position of mandible. In maximum clenching, balanced type of activity was seen bilaterally in normal occlusion. Whereas in changed occlusion, an unbalanced type of muscle activity was seen in temporalis muscle during maximum clenching. There was an overall decrease in activity in both the muscles during maximum clenching and during chewing. This decrease in activity was statistically significant in most of the times. A non-specific pattern of muscle activity resembling spasm in skeletal muscle -- a state of “hyperactivity” was also found during chewing in presence of occlusal interference. This spasm-like activity may cause pain in the muscles of masticatory apparatus. All these abnormal types of behavior of muscle were abolished after removal of high point and establishing the previous normal occlusion. It is therefore, for the clinicians to understand the importance of establishing occlusal equilibrium in day to day practice.

A preliminary study on the occlusal contact changes during retention in adolescent patients

To evaluate the changes of the occlusal contact characteristics in adolescent patients during 12 months after active orthodontic treatment. Twenty adolescent patients with Hawley retainers after active orthodontic treatment were divided into none occlusal interference group and occlusal interference group. The occlusion of the patients was examined with T-Scan II system directly after the appliance removal (T1) and after an average retention period of 12 months (T2). The changes of occlusal contact characteristics were observed. The disclusion time during protrusion, left and right lateral movements reduced significantly. The average disclusion time decreased [from (1.07 ± 0.87), (0.91 ± 0.47), (0.76 ± 0.43) s to (0.43 ± 0.25), (0.67 ± 0.41), (0.50 ± 0.27) s] significantly (P < 0.05). The occlusal interference disappeared in 4 patients and 1 patient with occlusal interference showed masticatory muscle symptom. The dynamic occlusion [from (1.25 ± 1.11), (0.84 ± 0.15), (0.52 ± 0.49) s to (0.35 ± 0.15), (0.36 ± 0.15), (0.33 ± 0.11) s] improved significantly (P < 0.05) in none occlusal interference group after retention and no statistical differences were found in the occlusal interference group (P > 0.05). The overall dynamic occlusion improved after retention in patients with retainers. The presence of occlusal interference affected the self-improvement process and increased the chance of the disorders of stomatognathic system, such as mandibular abnormal movements. Therefore, functional occlusion evaluation and final detailing were needed before appliance removal.

Orthodontics and the ideal occlusion – a review

Occlusion still remains a contentious issue, with the presence of occlusal interferences during mandibular movements being postulated to be detrimental to the health of the masticatory system. Orthodontic treatment plans are generally aimed at achieving an ideal static occlusion with the assumption that an ideal functional occlusion will follow. The following is an overview of both static and functional occlusion and its relevance to orthodontics, the evidence behind both types of occlusion, whether the attainment of an ideal occlusion is achievable clinically and the possible negative consequences of a non-ideal occlusion.

Occlusal Changes Following Posterior Tooth Loss in Adults. Part 3. A Study of Clinical Parameters Associated with the Presence of Occlusal Interferences Following Posterior Tooth Loss

Tooth positional changes following posterior tooth loss may alter arch forms and occlusal planes. This may result in the development of occlusal interferences. The purpose of this study was to determine clinical parameters associated with the presence of retruded contact position (RCP) contacts and occlusal interferences associated with posterior tooth loss. Diagnostic casts of 100 patients with at least one unopposed posterior tooth and 100 control patients were scanned and analyzed to record clinical parameters described in the earlier publications in this series. Clinical examinations identified the presence of RCP contacts and occlusal interferences. Five generalized linear models were developed to investigate the parameters associated with presence of RCP contacts, protrusive interferences, working side interferences, and nonworking side interferences. RCP contacts were associated with the degree of supraeruption of the unopposed tooth and the presence of other types of interferences. Protrusive interferences were associated with the presence and position of a tooth distal to the extraction site and the presence of other types of interference. Working side interferences were associated with tipping of the tooth mesial to the extraction site and the presence of other interferences. Nonworking side interferences were associated with the presence of other types of interference only. Unopposed posterior teeth are more likely to be involved in RCP contacts or interferences than their matched controls. Many teeth were involved in multiple interferences, and there appears to be a number of interrelationships between these. Initial RCP contacts have associations with the extent of supraeruption of the unopposed teeth. The presence and position of the teeth distal to extraction sites was significant when modeling protrusive interferences. Protrusive interferences are more prevalent where the site of tooth loss was bounded. Mesial tipping of the teeth distal to extraction sites reduced this effect. Working side interferences were associated with tipping of teeth mesial to the site of tooth loss. No associations between patient or tooth factors were found for nonworking side interferences, and the only association found for these interferences were with protrusive interferences at the sites.

EMG pattern of masticatory muscles in altered dentition - Part I

The aim of this study is to reveal how any alteration in occlusion results in functional disturbances in masticatory muscles, which may in turn develop TMJ pain dysfunction syndrome in the long ran.<br>Electromyography (EMG) of masseter and temporalis muscles (if ten adult individuals with normal occlusion and either 36 or 46 carious, was recorded in rest position and during chewing activity of mandible. After cavity preparation, inlay with high point (or occlusal interference) was fabricated, which seas fitted in the tooth and EMG recordings were repeated. Again the same recordings were done after stablishing the occlusal equilibrium.<br>Atypical pattern of muscle activity was observed only in presence of occlusal interference and obolished after removal of the same. This activity resembled the spasm in skeletal muscle. Spasm in masticatory muscles may initiate the symptoms of TMJ pain dysfunction syndrome.

Overeruption in unopposed posterior teeth

Objectives To determine the incidence and extent of overeruption in unopposed posterior teeth; to determine the incidence of occlusal interferences associated with unopposed posterior teeth; and to detect an association between the extent of overeruption and the presence of occlusal interference. Design and setting The study was a single centre clinical retrospective analysis. The setting was in the Combined Care Clinic of Leeds Dental Institute. The patients were undergoing routine restorative care by final year undergraduate dental students during 2000. Subjects and methods All patients over18 years of age with one or more unopposed posterior tooth, were invited to participate. A sample group of 120 subjects were recruited. A clinical occlusal examination was carried out and the presence of initial RCP contacts and excursive interferences were recorded. Study models were made and digitally scanned. Outcome measures Measurements of overeruption from the curve of Spee were made from the images obtained, by a single observer. Reliability of the measurements was assessed by means of a Bland Altman Plot. The presence and site of retruded contact position (RCP) contacts and excursive interferences were recorded by a single observer. Reliability of the measurements was assessed by means of Kappa scores. The association between overeruption and the presence of occlusal interference was examined using Spearmans Correlation Coefficient. Results A total of 120 subjects were recruited, with a total of 155 unopposed sites. Eighty-one of the sites belonged to male subjects, 74 to female subjects. The mean age of the group was 50.9 years, standard deviation 13.9. Eighty-three per cent of sites displayed overeruption (95% CI 78–90), ranging from under 0.5 mm to 5.4 mm. The reliability of the observations was found to be good. A total of 51.6% (95% CI 44–60) of unopposed teeth were involved in RCP contacts or excursive interferences. Thirty-two sites were involved in more than one contact or interference. The intra-examiner agreement was found to be good, using Kappa. The findings of the Spearman's correlation, show that if an association exists between overeruption and occlusal interference, it is weak, and of no statistical significance. Conclusions Eighty-three per cent of unopposed teeth are likely to overerupt, and the extent of the overeruption may be marked. The incidence and extent of overeruption is of clinical significance, not only in terms of treatment planning to prevent undesirable vertical movement, but also in the restoration of the edentulous space. The reliability of observations made in the study was found to be good, justifying the methodology. Fifty-one point six per cent of unopposed teeth are likely to be involved in RCP contacts or excursive interferences. The incidence is of clinical significance when planning the restoration of unopposed teeth, or the associated edentulous space. Only a weak statistical association was demonstrated between the degree of overeruption and the presence of occlusal interferences.

A study of the incidence of overeruption and occlusal interferences in unopposed posterior teeth.

To determine the incidence and extent of overeruption in unopposed posterior teeth; to determine the incidence of occlusal interferences associated with unopposed posterior teeth; and to detect an association between the extent of overeruption and the presence of occlusal interference. The study was a single centre clinical retrospective analysis. Setting The setting was in the Combined Care Clinic of Leeds Dental Institute. The patients were undergoing routine restorative care by final year undergraduate dental students during 2000. All patients over18 years of age with one or more unopposed posterior tooth, were invited to participate. A sample group of 120 subjects were recruited. A clinical occlusal examination was carried out and the presence of initial retruded contact position (RCP) contacts and excursive interferences were recorded. Study models were made and digitally scanned. Measurements of overeruption from the curve of Spee were made from the images obtained, by a single observer. Reliability of the measurements was assessed by means of a Bland Altman Plot. The presence and site of RCP contacts and excursive interferences were recorded by a single observer. Reliability of the measurements was assessed by means of Kappa scores. The association between overeruption and the presence of occlusal interference was examined using Spearmans Correlation Coefficient. A total of 120 subjects were recruited, with a total of 155 unopposed sites. Eighty-one of the sites belonged to male subjects, 74 to female subjects. The mean age of the group was 50.9 years, Standard deviation 13.9 Eighty-three per cent of sites displayed overeruption (95% CI 78-90), ranging from under 0.5 mm to 5.4 mm. The reliability of the observations was found to be good. A total of 51.6% (95% CI 44-60) of unopposed teeth were involved in RCP contacts or excursive interferences. Thirty-two sites were involved in more than one contact or interference. The intra-examiner agreement was found to be good, using Kappa. The findings of the Spearman's correlation, show that if an association exists between overeruption and occlusal interference, it is weak, and of no statistical significance. Eighty-three per cent of unopposed teeth are likely to overerupt, and the extent of the overeruption may be marked. The incidence and extent of overeruption is of clinical significance, not only in terms of treatment planning to prevent undesirable vertical movement, but also in the restoration of the edentulous space. The reliability of observations made in the study was found to be good, justifying the methodology. Fifty-one point six per cent of unopposed teeth are likely to be involved in RCP contacts or excursive interferences. The incidence is of clinical significance when planning the restoration of unopposed teeth, or the associated edentulous space. Only a weak statistical association was demonstrated between the degree of overeruption and the presence of occlusal interferences.

The therapeutic effects of occlusal equilibration in patients with craniomandibular disorders

In order to evaluate the role of occlusal factors in the etiology of CMD two groups of participants were selected for this investigation according to the value of the craniomandibular index ( CMI), Fricton and Schiffman 1975. The control group consisted of 17 participants, both male and female between 18 and 25 years of age with the preserved natural dentition, no indices of orthodontic treatment and with the value of the CMI = 0. The experimental group consisted of 15 participants, male and female, between 18 and 25 years of age with preserved natural dentition, no indices of orthodontic treatmen, but with evident signs and symptoms of CM disorders the CMI &gt;0). The chosen participants of the control and experimental group were subject to detailed occlusal analysis which included the number of occlusal contacts in the ICP, RCP,the type of lateral guidance of the mandible and the presence of occlusal interferences during mandibular movements. Using selective grinding the occlusal interferences were eliminated in participants of the experimetal group. The CMI was calculated in this group after selective grinding. The results of the occlusal analysis in this study point to the signifficantly greater number of mediotrusive, retrusive and protrusive interferences in participants of the experimental group The values of CMI before ( CMI I) and after selective grinding (CMI II) in the experimental group confirm the assumption that occlusal interferences play a significant role in the etiology of CMD.

Occlusal conditions just after the relief of temporomandibular joint and masticatory muscle pain.

When the signs and symptoms of temporomandibular joint disorders (TMD) are present, it is possible that occlusal conditions and mandibular movements are changed. 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. The comparison of occlusal conditions in 52 temparomandibular joint (TMJ) pain patients and 27 muscle pain patients with that in 60 asymptomatic controls was made. Occlusal examination in the patients was administered just after the relief of pain by bite plane therapy alone. The only occlusal factor which was associated with pain symptoms was no canine contact on the working side on laterotrusion. It is suggested therefore that further studies as regards this type of interference should be performed.

Penggunaan Poisoner sebagai Perawatan Pendahuluan pada Kasus Pergeseran Garis Median disertai Asimetri Wajah

There are two different types of midline shifting, dental and skeletal type, which are frequently followed by facial asymmetry and therefore would interfere the esthetics. The cause of midline shifiting is the presence of occlusal interference which might occur in many aspect of malocclusion. This condition may lead to a habitual occlusion that eventually attributes to the shifting. Positioner appliance is an alternative that can be utilized as pre/initial orthodontic treatment to accomodate the next treatment stage.

Mandibular function in children with a lateral forced bite

Open-close-clench cycles have been studied in 12 children with a lateral forced bite in order to investigate how the neuromuscular system of the mandible adapts itself in the presence of occlusal interferences. The mandibular movements were registered in a frontal plane at the central incisors with an opto-electronic registration technique. Series of 35 cycles were recorded to intercuspal position, against flat occlusal splints constructed in intercuspal raised and retruded positions, and against splints with occlusal stops in a retruded position. Average lateral displacements of the mandible during cycle series against flat occlusal splints were measured relative to cycle series to intercuspal position and relative to series against splints with occlusal stops in the retruded position. The lateral mandibular displacements were registered at maximal tooth-tooth or tooth-splint contact and at 7, 14, and 21 mm mouth-opening. It was found that the mandible in the subjects investigated is displaced to the forced bite side both during cycle series into intercuspal position as well as when occlusal contacts are eliminated by the use of flat occlusal splints.

A technique for evaluation of centric relation tooth contacts. Part II: Following use of an occlusal splint for treatment of temporomandibular joint dysfunction

The purpose of this study was to determine the effect of TMJ dysfunction on the recording of centric relation. Centric relation was recorded using an anterior occlusal stop and by bimanual manipulation. Changes in occlusal contacts were recorded before and after occlusal splint therapy in six subjects with TMJ dysfunction. The pantographic reproducibility index and clinical signs and symptoms were used to determine the presence or absence of dysfunction. Use of the anterior occlusal stop resulted in a more posterior, superior initial tooth contact position when compared with bimanual manipulation. Occlusal contact positions were less consistent in TMJ dysfunction subjects than in control subjects. Initial occlusal contacts changed toward centric relation as the dysfunction disappeared. Final occlusal contact was found on the side where clinical signs and symptoms occurred. The condyle on the affected side appeared to be repositioned posteriorly and superiorly in most instances. Occlusal splint therapy was more effective when the splint was adjusted weekly. This study indicates the need to eliminate TMJ dysfunction before recording centric relation or adjusting the occlusion. Occlusal interferences found with TMJ dysfunction are not the same as occlusal interferences found when TMJ dysfunction is absent. Abnormal features on pantographic tracings may aid in indicating the presence of occlusal interferences. Occlusal adjustment in the presence of TMJ dysfunction would result in erroneous occlusal reduction.