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Aim: The aim of this study was to verify in bruxism patients the possible efficacy of auricular stimulation in reducing the hypertonicity of some masticatory muscles., Methods: Forty-three bruxism patients were randomly allocated to 3 groups: acupuncture, needle contact for 10 seconds, no treatment (control). Helkimo's clinical dysfunction index (CDI) and anamnestic dysfunction index (ADI) were used to assess the functional state of the masticatory system. The resting electrical activity of the anterior temporalis (AT), masseter (MM), digastric (DA) and sternocleidomastoid (SCM) muscles was measured, according to Jankelson, with surface electrodes at baseline, after stimulation and continually for 30 minutes (120 measurements in total). The electromyographical variations in the 3 groups were studied with t test for independent samples., Results: Acupuncture and needle contact were superior to control in reducing the muscle hypertonicity of all muscles except SCM. In the comparison between acupuncture and needle contact the former showed better results only for the right TA and left DA (p = 0.000)., Conclusion: In this study it was possible to measure the efficacy of the stimulation of only one point or area, which is an ideal model for research in acupuncture. The auricular area we chose for stimulation was never used before for the purpose of relaxing masticatory muscles. Acupuncture and needle contact for 10 seconds showed similar effects.

Purpose: The aim of this study was to test the utility and validity of a newly developed EMG-based bruxism recording system, which allowed high-resolution digital recordings of the masseter EMG in the patient's home environment and systematic discrimination of artifact signals with the aid of semiautomated software., Materials and Methods: First, simulated bruxism and nonbruxism signals were recorded in two subjects; a total of 72 signals were obtained. Two independent scorers were shown these signals and asked to differentiate bruxism from nonbruxism signals. Second, EMG recordings were actually performed in 56 subjects for six consecutive nights. Using 10 randomly selected recordings, data cleaning was performed by the two scorers to remove any EMG artifact signals, and five bruxism event outcome variables (duration per event, hour, and night, and number per hour and night) were obtained twice with a 7-day interval., Results: The signal differentiation test using signals recorded during simulated tasks revealed that 97% of simulated bruxism and 87% of nonbruxism signals were recognized accurately by the scorers. A total of 317 night recordings, 94% of the scheduled recording nights, were successfully completed by 56 subjects without any substantial difficulty. The results of analysis of intraclass correlation coefficient of outcome variables scored by the two scorers revealed that intrascorer reproducibility varied between .70 and .97. The intraclass correlation coefficients for interscorer reliability were > or = .84., Conclusion: This EMG-based bruxism recording system has high utility and reasonable accuracy and precision.

While chewing and grinding movements have been observed in amphetamine addicts, recognition and management of this problem have rarely been highlighted. Botulinum toxin (BTX) has previously been demonstrated to be effective for bruxism associated with movement disorders, such as cranial-cervical dystonia. However, there is little information on its use in tardive bruxism. Here we report an amphetamine addict who presented with medically intractable bruxism, and discuss its pathophysiology and successful treatment with BTX.

Bruxism is considered to be a parafunctional disorder requiring treatment and is viewed as a risk factor for the development of temporomandibular disorders (TMDs). The purpose of this investigation is to examine the reliability of clinician judgements of bruxism severity. Twenty dentists who are faculty members in a dental school examined 29 stone casts and gold-plated models of individual teeth for evidence of bruxism. Ordinal ratings of bruxism severity for the 29 augmented models were made on two occasions, approximately 3 months apart. Inter-rater reliability among all clinicians, evaluated using intraclass correlation coefficients (ICCs), was poor at both time one and time two (i.e. ICC = 0.33 and 0.32, respectively), with somewhat better reliability found among those clinicians with above-average time elapsed since completion of dental training (i.e. ICC = 0.48 and 0.50 for time 1 and time 2, respectively). Three-month test-retest reliabilities were fair (ICC = 0.46) for the full group of raters and were unrelated to clinicians' degree of confidence in their ratings. These results indicate a need to standardize methods for clinical assessment of bruxism. Additionally, they have implications for studies using clinical assessments of bruxism to test the association between bruxism and other conditions such as TMDs.

A primary goal in the reconstruction of the dental implant patient is to achieve the lowest stress possible on the abutments, both artificial and natural. Bidez and Misch use the formula [figure: see text] [formula: see text] to explain that the stress can be easily lowered by increasing "A," by using larger implants, or by using additional implants. Another equally important method of lowering the stress is to reduce and manage the force application (F). The majority of completed implant cases can well tolerate applied forces from mastication and swallowing, both of which are close to 50 pounds per square inch, but it is the destructive power from DCS that can easily range from 500 to 1,000 pounds per square inch with which this article is concerned.

The purposes of this study were to develop and verify the a portable nocturnal bruxism monitoring and analysis device equipped with a microcomputer, and to clinically apply the device to know the actual conditions of bruxism patients. EEPROM was installed in the device for the data recording, and after the data collection, the recorded data was entered into a personal computer via serial port. After confirming the accuracy of the device, a total of 30 subjects were enrolled in this study to monitor their bruxism activities for 3 nights. Bruxism self-aware group consisted of 14 subjects, 7 males and 7 females, and unaware group consisted of 16 patients, 8 males and 8 females. Most of the subjects reported that the new device was easy to handle. The average bruxism time per hour and the average bruxism lasting time were 223.8 +/- 112.0 and 3.9 +/- 2.9 s in the self-aware group, and 49.3 +/- 38.3 and 0.8 +/- 0.7 s in the unaware group, respectively. The bruxism self-aware group showed statistically longer average bruxism time per hour and the average bruxism lasting time. It was confirmed that the new bruxism monitoring and analysis device is practical for clinical application to monitor and analyze the electromyographic activities.

No clear description can be found regarding the lateral position when examining non-working-side occlusal contacts. The objective of this study was to test the hypothesis that the non-working-side contact pattern varies with the mandibular position. The characteristics of the non-working-side contact pattern were also determined relative to the working-side contact pattern. Occlusal contacts of 86 young adults were examined using shim stock in standardized lateral positions: 0.5, 1, 2 and 3 mm from the maximum intercuspation (MI), where the 0.5, 1 and 2 mm positions were defined as lateral positions close to the MI and the 3 mm position as an edge-to-edge position. The frequency of non-working-side occlusal contacts decreased gradually from 0.5 to 3 mm position. The frequency of non-working-side contacts was significantly greater in the 0.5 and 1 mm positions than in the 3 mm position. Non-working-side occlusal contacts occurred in nearly half of the 0.5 mm positions. Non-working-side contacts were significantly less frequent with canine protection than with group function for the 0.5 and 1 mm positions. There were no significant differences between the two occlusal schemes for the 2 and 3 mm positions. In conclusions, the non-working-side contact pattern varied with the mandibular position. These results suggest that clinical examination should include contact patterns both in a position close to the MI and in an edge-to-edge position, i.e. in functional and parafunctional ranges. Likewise, data from occlusal contact research should include a standardized definition of mandibular position.

Sleep bruxism (SB) is an oral activity associated with jaw movements and tooth grinding. Sleep bruxism is believed to be highly variable over time, with subjects showing no activity on some nights and intense activity on others. Assessment of SB variability in individual patients is necessary for clinical trials designed to estimate the efficacy of SB management strategies. The present study analysed SB night-to-night variability over time in nine moderate to severe SB patients. Excluding the first night for habituation, a total of 37 nights were analysed, with a range of 2-8 nights per subject. The interval between the first and the last recording was between 2 months and 7.5 years. The outcomes were the number of SB episodes per hour, number of SB bursts per hour and number of SB episodes with grinding noise. The within subject variability of the three SB oromotor outcomes was evaluated using standard deviation (SD) and coefficient of variation. To verify the diagnosis of subjects over time, the values of the oromotor outcomes were compared with a standard research diagnostic cut-off: (1) Number of SB episodes per hour >4, (2) Number of SB bursts per hour >25, (3) Number of SB episodes with noise per night >1 (Lavigne et al. 1996). The mean coefficient of variation for the nine subjects was 25.3% for SB episodes per hour, 30.4% for SB bursts per hour and 53.5% for episodes with noise. Linear regression showed that the number of SB episodes per hour of stages 1 and 2 explains a large proportion of the variability. The SB diagnosis remained constant over time for every subject: 35 nights over 37 respected criteria 1 and 2, while grinding was present every night. These results indicate that while the SB diagnostic remains relatively constant over time in moderate to severe sleep bruxers, individual variability could be important in some SB patients.

Statement of Problem: An accurate, easy-to-use, long-term method other than EMG is needed to monitor bruxism., Purpose: This article presents pilot data on the reproducibility, validity, and utility of an intrasplint piezoelectric film method., Material and Methods: Simulated bruxism behaviors (steady-state and rhythmic clenching, grinding, and tapping) in 5 subjects were recorded with the use of both masseter EMG and an intrasplint piezoelectric film method., Results: Correlation coefficients calculated for simulated bruxism event duration with the use of a masseter EMG or an intrasplint piezoelectric film method were 0.99 for tapping and steady-state clenching, 0.96 for rhythmic clenching, and 0.79 for grinding., Conclusion: Piezoelectric film has its limitations and does not faithfully capture sustained force magnitudes. However, for the target behaviors associated with bruxism (tooth grinding, clenching, and tapping), it appears to faithfully reproduce above-baseline events with durations statistically indistinguishable from those recorded with masseter EMG. Masseter EMG was poorest at detecting a simulated side-to-side grinding behavior.

This article will address the evolution of occlusal disease from childhood and the deciduous dentition forward. It will include the evolution of anterior wear with emphasis on "cross over" of the mandible. Having classified the types and extent of occlusal disease, new evidence will be shown, on the adult dentition with pathognomonic manifestations, of cross-over or bruxed-braced occlusal disease. Its potential effect on restorative dentistry and dental implants will be discussed.

The aim of this study was to clarify the relationship between the mandibular position with tooth contacts and jaw-closing muscle activity during sleep using electromyography and newly devised equipment for detecting tooth contacts and also to confirm the validity of this system. Five males volunteered for this study and three of them reported their bruxing during sleep. Occurrences of tooth contacts at eccentric mandibular positions in addition to the intercuspal position during sleep were detected using micro photo sensors and sensor targets prepared for the individuals. Electromyographic activities (EMG) from right and left masseter and anterior temporal muscles were also recorded. Results of the polygraphic recordings demonstrated that the mandibular positions during bruxism could be distinguished clearly whether it's in the right or left position, or has no lateral deviation, and further, that bruxing events could be categorized based on mandibular position pattern. The relationship between the mandibular position and muscle activity could be evaluated using this system. The study suggested the validity of the system for measuring nocturnal bruxing events.

Although there is a controversy about the importance of psychological factors in the development, enhancement and perpetuation of bruxism and other parafunctional activities, the contribution of a psychologist in the treatment of the individual patient is recommended. This contribution consists of diagnostic examination and treatment, most often a short cognitive behavior modification therapy. Because bruxism is mostly examined and treated in relation to the complaints it might cause, especially CMD-complaints, diagnosis and treatment are mostly directed at both. For the diagnosis a questionnaire is used, including a psychological test, which is followed by one or more interviews. The treatment is directed at learning to recognize bruxism activities, to practice alternative behavior, and to learn to cope better with situations that may lead to an increase of bruxism.

Tooth clenching or grinding may cause serious problems for patients and dentists. Symptoms occur at the level of the teeth (wear), the periodontium and the musculoskeletal system. In the past, the definition of bruxism often was vague and controversial, and also a clinical diagnosis appeared to be difficult. More recently research in the sleep laboratory, using a combination of electromyography video- and sound recording, made it possible to distinguish between bruxism and other oral behaviour. The association between pain and dysfunction of the masticatory system with bruxism is still unclear.

The purpose of this study was to establish a clinical method for diagnosing diurnal bruxism in denture wearers by recording masseter and anterior temporal electromyograph (EMG) activity. Seven suspected bruxists and five normal patients who wore complete dentures and/or distal extension base removable partial dentures were selected for participation. EMG activity in both the masseter and the anterior temporal muscles was recorded bilaterally during silent reading (10 min), maximal voluntary clenching (MVC), tapping in centric occlusion, lateral movements, chewing and swallowing. No significant differences of EMG activity were found between the groups during tapping, lateral movement, chewing and swallowing (P> 0.05). However, during 10 min of silent reading, a significant difference was found between the groups when comparing masseter muscle activity (P < 0.05). A threshold of 10% of MVC of at least 3-s duration was used to define an individual bruxism event. When the muscle activity recorded during silent reading was further analysed using these criteria, the control group displayed no bruxing activity while the suspected bruxist group displayed a mean frequency of six bruxism events (range 2-10). It was concluded that: (a) masseter muscle activity recorded during 10 min of silent reading showed significant difference between the groups; (b) the criteria selected in this study for the detection of sleep bruxism can also be used to assess diurnal bruxism; and (c) it is possible to diagnose diurnal bruxism in denture wearers by measuring the masseter EMG activity during 10 min of silent reading.

With the aim to examine the dermatoglyphic patterns of finger and palm, 38 bruxism patients, 18 being female were studied. Fingerprint patterns in bruxism has previously been discussed in a few papers, but this is the first paper about dermatoglyphic patterns of palm in bruxism. The aim of this study of finger and palm prints in patients with bruxism were to discuss the importance of dermatoglyphic patterns in the diagnosis and etiology of the disease. Bruxism patients demonstrated an increase in frequency of whorls and a decrease in frequency of ulnar loops than the controls. Patients with bruxism demonstrated a lower frequency of atd angle than controls. Augmentation of I loops and t triradii and diminution of IV, H and t" triradii were observed in bruxism patients. Furthermore, the main line A ended more frequently in sector 5' in bruxism patients when compared with controls. There is no significant difference between the total finger ridge counts (TRC) and a-b ridge counts the subjects with bruxism and that of the controls. The dermatoglyphic patterns of finger and palm was significantly different in children with bruxism. When combined with other clinical features in bruxism, dermatoglyphics can serve to strengthen a diagnostic impression.

The two major muscle groups used during clenching activity are the masseter and temporalis muscles. EMG readings of the masseter and temporalis muscles rise significantly during times of macro-clenching. Clenching occurs when the masseter and temporalis muscles contract, pulling the mandible superiorly. The continued contraction of the masseter and temporalis muscles results in compression forces on the teeth and temporomandibular joints. Theoretical joint loading models are utilized to demonstrate the load on the TMJ due to forces generated by the masseter and temporalis muscles. This study measures the EMG readings during bilateral macro-contraction of the masseter and anterior temporalis muscles. An appliance is fabricated to disengage the posterior teeth and a second series of EMG readings are taken to record lowered EMG readings. The vector forces of the reduced EMG's recordings demonstrate reduced condylar compression during macro-clenching.

Background: One hypothesis to explain selective serotonin reuptake inhibitor (SSRI)-induced bruxism states that SSRIs increase extrapyramidal serotonin levels, thereby inhibiting dopaminergic pathways controlling movement. Previous reports have emphasized buspirone's postsynaptic dopaminergic effect as a partial antidote to the suppressed dopamine levels., Case Reports: Four patients, recently started on treatment with the SSRI sertraline, presented with new-onset complaints attributable to SSRI-induced bruxism. All 4 responded to adjunctive buspirone, a serotonin-1A (5-HT1A) receptor agonist, with relief of bruxism and associated symptoms., Discussion: We expand the hypothesis put forth in previous reports by proposing that buspirone is not only acting postsynaptically in the extrapyramidal system, but also presynaptically on serotonergic neurons that influence masticatory modulation in the mesocortical tract. Our 4 cases support the concept of buspirone acting as a full agonist at the presynaptic 5-HT1A somatodendritic receptors located on the cell bodies of raphe serotonergic neurons that project to the ventral tegmental area (VTA) of the midbrain. These serotonergic neurons modulate the firing of the mesocortical tract, which itself projects from the VTA to the prefrontal cortex and acts on masticatory muscle activity through inhibiting spontaneous movements such as bruxism. While the literature is confusing and contradictory on definitions of bruxism and etiologies of incompletely understood movement disorders, we believe SSRI-induced bruxism is best conceptualized as a form of akathisia.

Two hundred and seventy-six CMD patients referred consecutively for diagnosis and treatment over a period of four years were assessed. Two hundred and eleven were classified as bruxers according to the use of a questionnaire and clinical examination. One hundred (47.39%) presented clinical characteristics of mild bruxers, 66 (31.27%) presented moderate bruxism and 45 (21.32%) demonstrated severe bruxism. Severe bruxers presented the lowest degree of jaw opening (39.21 mm) and highest prevalence of capsulitis (97.77%), retrodiskal pain (84.44%) and disk-attachment pain (48.88%). As compared to the mild and moderate groups, severe bruxers also demonstrated significantly higher prevalence of protective splinting and transient locking or recent history of intermittent locking, masticatory pain, reciprocal clicking and signs and symptoms of Myofascial Pain Dysfunction Syndrome (MPDS). Because higher prevalence of specific muscle and joint disorders were observed in bruxers and such prevalence was progressive from the mild to the moderate and severe group, it may be concluded that bruxing behavior is a significant factor in the etiology and progression of muscle and joint disorders. Based on the review of the literature, the analysis of our data in comparison to other studies allowed us to conclude that severe bruxers are more impaired by muscular and joint disorders as compared to mild and moderate bruxers.

Buccal mucosa ridging and tongue indentation have been considered as one of the visible and reliable signs of bruxism. However, there have not been any reports justifying this relationship scientifically. Moreover, there have not been any studies reporting specific procedures to assess them. Thus, the purpose of the present study was to determine the clinical incidence of buccal mucosa ridging and tongue indentation and assess the possible relationship between certain factors that can influence their occurrence. A total of 244 (178 males and 66 females) dentulous adults from 20 to 59 years of age, who were employees at the Bank of Yokohama, were randomly selected. At first, the buccal mucosa ridging and tongue indentation were classified into three groups based in their intensity: none, mild, and severe. The incidence of both conditions in the different age groups, as well as the incidence by gender was evaluated. Furthermore, the possible relationships between buccal mucosa ridging and tongue indentation and age, gender, clenching awareness, grinding awareness, headache, neck stiffness, vertical dimension, temporomandibular joint (TMJ) pain to palpation, masticatory muscle tenderness to palpation, and the presence of premature contacts were evaluated using the chi-square test. A positive relationship was found between the occurrence of buccal mucosa ridging and tongue indentation and gender (p < 0.01); both conditions were observed more frequently in females than in males. A positive relationship was also found to age; the group between 20-29 years old showed the highest incidence. The vertical dimension had a positive relationship with the occurrence of both buccal mucosa ridging and tongue indentation. Other factors evaluated did not show any correlation.

The purpose of this investigation was to test for an association between the craniofacial morphologies of bruxers and nonbruxers. The sample for this retrospective descriptive comparative study consisted of 28 Caucasian dental school subjects. Sixteen were bruxers and 12 were nonbruxers. The determination of bruxism was based on a six-item questionnaire as well as objective measures of the severity of tooth wear as analyzed from dental casts. Craniofacial morphology was determined directly using anthropometric spreading calipers. Craniofacial measurements included glabella-opiscranion, euryon-euryon, nasion-gnathion, zygoma-zygoma, and gonion-gonion. From these measurements, the following indices were calculated: cephalic (Gla-Op/Eu-Eu), facial (Na-Gla/Zy-Zy), gonial (Zy-Zy/Go-Go), and gonial height (Na-Gla/Go-Go). This study found no differences in the craniofacial morphologies of bruxers and nonbruxers, nor was there a difference in overbite. There was, however, a statistically significant difference in the bizygomatic (Zy-Zy) and cranial (Eu-Eu) widths of bruxers compared with nonbruxers.

This study was performed to test the hypothesis that emotionally stressful states measured by the urinary catecholamines may affect the development of bruxism. Three hundred and fourteen children, boys and girls, aged 6-8 years were included in this study. Bruxism was recorded by a clinical examination and an interview. Positive evidence of this parafunction was defined as the presence of both historical and clinical indicators. Information concerning systemic and socio-economic factors was collected by a questionnaire. A 24-h urine sample was collected for each subject and analysed by the high performance liquid chromatography technique to assay the catecholamine content. Of the total of 273 children who had a complete 24-h urine sample, 167 were identified to be with and without positive evidence of bruxism. The logistic multiple-regression analysis was carried out to test whether the presence of bruxism was affected by the variables studied; 95% probability was used. The results showed that epinephrine and dopamine had a significant and strong association with bruxism. The data therefore provide support for the concept that emotional stress is a prominent factor in the development of bruxing behaviour.

The relative roles of genetic and environmental factors in bruxism are not known. In 1990 a questionnaire sent to the Finnish Twin Cohort yielded responses from 1298 monozygotic and 2419 dizygotic twin pairs aged 33-60 years. We used structural equation modelling to estimate genetic and environmental components of variance in the liability to bruxism. There was a significant gender difference both in childhood (P = 0.001) and adult (P = 0.007) bruxism. Females compared to males reported childhood bruxism 'often' 5.2% vs 4.1% and 'sometimes' 17.4% vs 17.3%, and as adults 'weekly' 3.7% vs 3.8% and 'monthly' 3.9% vs 4.6%, respectively. Bruxism in childhood and adulthood is highly correlated (0.86 in males and 0.87 in females). The proportion of total phenotypic variance in liability to bruxism attributed to genetic influences in childhood bruxism was 49% (95% CI 37-60%) in males and 64% (55-71%) in females, and for adults 39% (27-50%) among males and 53% (44-62%) among females. The correlation between the genetic effects on childhood bruxism and the genetic effects on adult bruxism was estimated in a bivariate model to be 0.95 (95% CI 0.94-0.96) in males and 0.89 (0.88-0.90) in females. Bruxism appears to be quite a persistent trait. There are substantial genetic effects on bruxism both in childhood and as adults, which appear to be highly correlated.

The study of sleep bruxism is usually based on clinical history, signs and symptoms. The recording of electromyographic signals with either ambulatory portable home recorders or with polysomnographic techniques in the laboratory environment allows collection of objective data. The present study showed a 100% agreement with clinical evaluation in the recognition of bruxism episodes from the masseter electromyogram recorded with portable recorders and using the polysomnographic technique. On the contrary, scorers had difficulties in discriminating between different types of episodes (phasic, tonic and mixed), the between-scorers agreement varied between 62% and 63% and the kappa-values between 0.43 and 0.33. The ideal time base at which electromyographic signals should be integrated to allow for a good discrimination of bruxism patterns is 0.06 s. The results indicate that portable electromyography recorders are a valuable complement to polysomnographic recordings of orofacial motor activities as they provide a very good recognition rate with adequate time base data collection.

We studied 24 bruxers (23-67 years old). They often complained of orofacial and bodily pain and presented autonomic symptoms (sweating 23%, palpitations at night 62%, decreased libido 50%); 19% had increased blood pressure requiring treatment, and 65% reported frequent headaches in the morning. Deep sleep and rapid eye movement (REM) were delayed. An average of 167 orofacial episodes developed during the night. The mean number of masseter bursts strictly defined as bruxism was 79, the mean delay for the first occurrence after sleep onset 18 minutes. The majority of bruxism occurred in stage 2 sleep and REM sleep. The mean number of shifts of sleep stages was 70, one-third occurring within the first minute following a bruxing episode, and 15% of bruxing episodes developed after a shift in sleep stage. Electroencephalogram showed alpha-delta pattern in 15% of the subjects. Short-lasting alpha activity was often encountered during the 10 seconds preceding the development of a bruxing episode. Tachycardia developed at its onset, persisting for 10 seconds. We suggest that, as a minor alarm response to endogenous/exogenous stimuli, arousal develops and is often followed by motor activation, such as a burst of bruxing, with, as in any situation when motor activity suddenly increases, a secondary increase of heart activity.

Signs and symptoms of craniomandibular dysfunction (CMD) and social medical history were reported in 29 subjects, aged 23-68 years, with longstanding (5 years or more) bruxing behaviour. The subjects were selected from answers to an advertisement in the local newspaper. The subjects presented many symptoms of a general character including somatic and psycho-social problems, sleep disorders (72%), and pain (86%). More than half of the subjects (55%) had symptoms every day. Frequent aches in the neck, back, throat or shoulders were reported by 69% and frequent headache by 48% of the subjects. The most common symptoms of CMD were pain in the face or jaws (48%), stiffness in the jaws in the morning (44%), temporomandibular joint (TMJ) sounds (34%) and fatigue in the jaws during chewing (38%) and the most common clinical signs were more than three muscles tender on palpation (76%), TMJ-sounds (55%) and tenderness of TMJ on lateral palpation (66%). There was a statistically significant correlation between frequent tooth clenching and headache, pain in the neck, back, throat or shoulders, sleep disorders and high scores of the clinical dysfunction index (Di). The frequent clenchers had higher score values than the 'non-clenchers' for pain in the face and the jaws; headache; pain in the neck, back, throat or shoulders and the clinical dysfunction index (Di). These findings indicate a causal relationship between frequent tooth clenching and signs and symptoms of CMD, including headache and pain in the neck, back, throat or shoulders and high pathogenicity for frequent clenching. However, the material in this study is small and some precaution must be taken prior to generalized conclusions. More studies are required, especially sleep laboratory investigations, which could perhaps give answers to some of the numerous questions in this unexplored field of odontology.

Seventeen patients with a mean age of 7.33 (range 2.7-12.7) years with Rett syndrome (a progressive neurological disorder that occurs mainly in females) were evaluated for oral manifestations and habits. The most frequent habits were digit/hand sucking and/or biting (17/17), bruxism (14/17), mouth breathing (7/17), drooling (5/17), and tongue thrusting (5/17). Gingivitis (13/17) was the most common alteration of soft tissues. Only 2.7% of tooth surfaces were decayed. Nonphysiological dental attrition was present in 71% (12/17) of the children. Palatal shelving could be observed in 53% (9/17) of the children, probably related to the digit/hand sucking and/or biting habits. A high prevalence of anterior open bite (9/17) was observed. No patients exhibited anomalies of tooth number, size, form, structure, or eruption.

Bruxism is a parafunction observed both in young and adult populations. The mean prevalence is about 20% and is decreasing with age. Women appear to clench more frequently than men. Often, bruxism is understood as both clenching with occasional tooth contact or grinding. A correct and validated definition has only recently been suggested. Many symptoms are assigned to this process, although few symptoms scientifically can be used as specific diagnostic criteria. The symptoms most often associated with bruxism like muscle-stiffness and -pain, limitation of mouth opening. TMJ-internal derangements, toothwear, are also found in TMD-patients. Because the bruxism-process is not only a problem for the patient, who suffers from pain, dysfunction and possible toothwear, it concerns also the dentist. It is essential that those who treat the bruxist-patient, have an understanding of the etiology, diagnosis and management of bruxism, of the many described oral parafunctional behaviors (oromotor behavior). This literature-review could not find a causal etiological mechanism between the occurrence of TMD-symptoms and the bruxism although a relationship between those two conditions has been described.

The rate of abrasion of dental surfaces during short periods of time is difficult to measure clinically, but one quantifiable method is the use of the Bruxcore bruxism monitoring device. The aim of this study was to estimate the interobserver and intraobserver variation in the Bruxcore system using different reading methods. Fifteen volunteers used individually fabricated Bruxcore devices during 4 consecutive nights, and this procedure was repeated after 6 weeks. The abraded areas of the 30 Bruxcore devices were measured by two observers on two occasions and with three methods: microscope without a reference scale; microscope with a reference scale; and a computer-aided system. Intraobserver variation was small (5%), but interobserver variation was statistically significant for all three methods. The computer-aided system was superior to the other two methods. The interaction between Bruxcore values and observers was statistically significant for the microscope methods but not for the computer method. This was a desired property, indicating stability of the computer-aided method over the range of Bruxcore values observed. Small measurement errors, independent of the size of the measurements, can be expected using a trained observer and a computer-aided method for reading the Bruxcore bruxism monitoring device.

Experimental equipment for recording mandibular excursive position during nocturnal bruxism has been devised. The equipment consists of chromium-cobalt alloy cast frameworks for each upper and lower dental arch and two pairs of tiny magnetic sensors and magnets, capable of electromyographic (EMG) recordings of the bilateral masseter muscles and simultaneously recording mandibular position. The two subjects tested were confirmed to be bruxing during sleeping. Although EMG records for the two subjects showed a common EMG pattern as a bruxer, the sensor records revealed that one subject was a bilateral bruxer and the other bruxed almost unilaterally. The present study demonstrated that this newly devised equipment is practical for studying mandibular position during nocturnal bruxism.

Dental disease can be described as a permanent alteration of loss or function of those parts generally cared for by dentists. Specifically, these include the teeth, periodontal tissues and associated dental structures. Historically the breakdown and subsequent loss of tooth structure was caused by dental caries. It has also been observed that tooth loss can result from overuse-abuse referred to as bruxism or bruxamania.

Surface electromyography of the masseter and electrocardiogram recordings of heart activity during sleep were performed on nine subjects who suffer from an oral motor dysfunction (bruxism during sleep. Signals were monitored in the subject's home sleeping environment over 4 consecutive nights. A total of 36 nights of data were analyzed to perform the following: (1) describe the nature and magnitude of total masseter muscle electromyographic activity above a minimum threshold of 3% of each subject's individually established maximum voluntary contraction level; and (2) describe electrocardiograph rate changes (using the R-R interval) that occurred in relation to these electromyographic elevations. From these data, criteria for detection of bruxism events were established and combined into a fully automated event detection algorithm. The mean number and duration of the detected bruxism events are reported. The underlying logic for the criteria selected, and what effect other possible criteria would have on the separation of abnormal from normal motor events, is also presented and discussed.

Signs and symptoms of craniomandibular dysfunction (CMD) and oral parafunctions were re-examined in subjects, 25-26 years of age, 10 years after the first examination. Forty subjects had restored dentitions at both examinations (group F), 18 subjects with previously intact dentitions had had fillings in their teeth during the follow-up period (group FI), and 11 subjects had intact dentitions at both examinations (group I). Signs and symptoms of CMD were more common among the subjects in group F than in the original group of subjects with intact teeth (group 10). In accordance with the first study most of the symptoms were mild and of low frequency. However, frequent symptoms were only found among the subjects in group FI and group F and more severe frequent symptoms only in group F. There was an increase of the symptoms in group FI and group F. Frequent tooth clenching and frequent tongue pressing were more common in group F and there was a statistically significant increase in group FI concerning tooth clenching and tooth grinding and in group F concerning tooth grinding, tooth clenching and tongue pressing. Together with the correlations found between tooth clenching and signs and symptoms of CMD, the findings in this study and the personality study indicate a possible causal relationship between oral parafunctions, signs and symptoms of CMD, personality and fillings. A hypothesis for the possible mechanisms is presented. However, the findings are not conclusive and more studies are necessary, and for further interpretation of the results, studies from other research centres would be of interest.

Purpose: This study determined the prevalence and specific anatomic types of disc displacement in asymptomatic versus symptomatic subjects using magnetic resonance imaging (MRI)., Patients and Methods: A detailed MRI assessment was performed on both temporomandibular joints (TMJ) in 76 volunteers and 102 successive patients. Attention was placed on the functional aspects of disc displacement with and without reduction and on the anatomic aspects of disc displacement in the anterior, lateral, medial, anterolateral, and anteromedial directions. These assessments were made by radiologists blinded to the clinical information., Results: Disc displacement was found in at least one joint in 25 of 76 (33%) of asymptomatic subjects and 79 of 102 (77%) of symptomatic subjects. The anatomic types of disc displacement between groups was not statistically significant (P = .55). However, there was a significant difference between asymptomatic and symptomatic subjects, with an odds ratio of 3.91 for disc displacement with reduction and 42.71 for disc displacement without reduction (P < .001)., Conclusion: Although there was a 33% prevalence of disc displacement in asymptomatic volunteers, there was a highly significant difference in the prevalence of internal derangement in symptomatic subjects. Bruxing was statistically linked to TMJ disc displacement and could explain the anatomic variation in abnormal disc position.

The clinical validity of diagnostic criteria for sleep orofacial motor activity--more specifically, bruxism--has never been tested. Polysomnographic recordings from 18 bruxers and 18 asymptomatic subjects, selected according to American Sleep Disorders Association criteria, were analyzed (1) to discriminate sleep bruxism from other orofacial motor activities and (2) to calculate sensitivity, specificity, and predictive values of research criteria. Clinical observations and reports revealed that all 18 bruxers reported frequent tooth-grinding during sleep. Tooth wear was noted in 16 out of 18 bruxers and jaw discomfort reported by six of them. These findings were present in none of the controls. The analysis of polysomnographic data showed that the asymptomatic subjects presented a mean of 1.7 +/- 0.3 bruxism episodes per hour of sleep (sustained or repetitive bursting activity in jaw closer muscles), while bruxers had a significantly higher level of activity: 5.4 +/- 0.6. Controls exhibited 4.6 +/- 0.3 bruxism bursts per episode and 6.2 (from 0 to 23) bruxism bursts per hour of sleep, whereas bruxers showed, respectively, 7.0 +/- 0.7 and 36.1 (5.8 to 108). Bruxism-like episodes with at least two grinding sounds were noted in 14 of the 18 bruxers and in one control. The two groups exhibited no difference in any of the sleep parameters. Based on the present findings, the following polysomnographic diagnostic cut-off criteria are suggested: (1) more than 4 bruxism episodes per hour, (2) more than 6 bruxism bursts per episode and/or 25 bruxism bursts per hour of sleep, and (3) at least 2 episodes with grinding sounds. When the polysomnographic bruxism-related variables were combined under logistic regression, the clinical diagnosis was correctly predicted in 81.3% of the controls and 83.3% of the bruxers. The validity of these clinical research criteria needs now to be challenged in a larger population, over time, and in subjects presenting various levels of severity of sleep bruxism.

A total of 416 patients aged 40 to 60 suffering from abnormal teeth abrasion were fitted with cermet dentures. Orthodontic treatment was preceded by therapeutic and surgical preparation of the teeth and periodontium and by functional and adaptation rearrangement of the maxillodental system, if indicated. Remote results were assessed after 2 to 12 years. Due to such preparation good results were attained in 95.9% patients. Complications were observed in only 4.1%: exacerbation of periodontitis, ceramic facing chipping off, insertion of abutment teeth, and functional overload of the periodontium.

A total of 868 patients aged 25 to 68 with various types of occlusion and dentition defects were examined. 212 (24.4%) patients presented with a shortened interalveolar distance (height of occlusion). Abnormal abrasion of hard dental tissues, dentition defects in the lateral sections of dental arches, abnormal occlusion (deep or prognathic), reduced tolerance of periodontal tissues, and dysfunction of the masticatory muscles (bruxism) were found to be the pathogenetic factors leading to the development of this condition. Dysfunction of the masticatory muscles was detected in 41.5% of patients with shortened interalveolar distance and dysfunction of the temporomandibular joint in 9.9%; moreover, in many of them traumatic occlusion and disorders in the regional circulation in the periodontium of teeth exposed to overexercise were observed. Orthodontic treatment of patients with shortened interalveolar distance was carried out in two stages: the first stage consisted in functional and adaptation restructuring of the maxillodental system by repair of the height of occlusion and normalization of the mandibular position on a plastic cup which the patients wore for 3 months, and then the second stage ensued, at which they were fitted with dentures. Good results were attained in 95.7% patients.

Long-term electromyography with portable recorders allows the study of muscle activity in the natural environment to investigate whether muscle overuse or oral habits may contribute to initiate or perpetuate a myoarthropathy of the masticatory system. At present, little is known about the behaviour of masticatory muscles over long time periods. The aim of this preliminary study was to define parameters which allow the automatic recognition of different types of oral activities from the electromyogram form. A programme with functional and parafunctional activities was performed by four volunteers (total of 333 functional and 82 parafunctional recordings). Electromyograms of the masseter and temporal muscles were recorded by means of a self-developed portable intelligent solid state recorder. Signal mean level (mw) and dynamics (dw) within a sliding window were determined. Temporal muscle recordings allowed better discrimination between function and simulated parafunction. The average of mw for clenching was 51.4 +/- 3.5% and for tooth grinding 21.2 +/- 2% of the peak electromyogram value at maximum voluntary clench. At 0.96 s sliding window duration, clenching, tooth grinding and chewing signals had maximum separation, using dw/mw as parameters (average: 0.16 +/- 0.01 for clenching, 0.39 +/- 0.01 for teeth grinding and 0.88 +/- 0.01 for chewing).

Analysis of the occlusion and function of the masticatory system should be part of a thorough examination of the patient. This is especially important when signs or symptoms of functional disturbances are present or when planning extensive occlusal restorations. This article has strived to present (1) indications for occlusal analysis; (2) how to perform occlusal analysis and diagnostic aids that can be helpful in occlusal analysis; and (3) how information gained through occlusal analysis can be used in differential diagnosis of the three most common functional disturbancies of the masticatory system: trauma from occlusion, parafunction, and TM disorders.

This article describes the various sensory and motor disorders that afflict the orofacial region. These abnormalities are broadly separated into three groups of pathologic conditions: temporomandibular disorders; chronic orofacial pain disorders; and oral motor disorders. This article focuses on the diagnostic features of each specific disorder, suggesting alternate nomenclature for each disorder.

A study of frequency of occurrence of signs and symptoms of temporomandibular dysfunction (TMD) by means of questionnaires and clinical examination was performed at New York University College of Dentistry. Ninety children, ages 3 to 16, were examined.

This study evaluated the effect of different rates of increase of occlusal force and of removal and replacement of the electromyographic electrodes on the amount of occlusal force needed to trigger a modified electromyographic measuring unit. Seven subjects placed the electrodes on the masseter area on one side, and bit ipsilaterally on a bite force transducer. The electromyographic recorder was adjusted to be triggered only when the subject clenched. Occlusal force was recorded simultaneously with triggering of the electromyographic recorder. The subjects performed two series of five repetitions of clenching at each of four different rates of increase of force, by visual feedback from a second oscilloscope until the electromyographic recorder was triggered, and an occlusal force measurement was made from the first oscilloscope. Repeated measures of ANOVA analysis revealed no statistically significant differences among the different rates of increase in occlusal force or between the two recording series. Interaction between the two factors also was not significant. The intraclass correlation coefficient was large and statistically significant, indicating that this device was reliable for this method.