Assessment of sleep bruxism, orthodontic treatment need, orofacial dysfunctions and salivary biomarkers in asthmatic children

OBJECTIVE

To evaluate the sleep bruxism, malocclusions, orofacial dysfunctions and salivary levels of cortisol and alpha-amylase in asthmatic children.

DESIGN

108 7-9-yr-old children were selected from Policlinic Santa Teresinha Doutor Antonio Haddad Dib (asthmatics, n=53) and from public schools (controls, n=55), Piracicaba, SP, Brazil. Sleep bruxism diagnosis was confirmed by parental report of grinding sounds and the presence of shiny and polish facets on incisors and/or first permanent molars. The index of orthodontic treatment need was used for occlusion evaluation. Orofacial dysfunctions were evaluated using the nordic orofacial test-screening (NOT-S). Salivary cortisol and alpha-amylase were expressed as "awakening response" (AR), calculated as the difference between levels immediately after awakening and 30 min after waking, and "diurnal decline" (DD), calculated as the difference between levels at 30 min after waking and at bedtime. Data were analyzed using Shapiro-Wilk/Kolmogorov-Smirnov, Chi-square, unpaired t test/Mann-Whitney and paired t/Wilcoxon tests.

RESULTS

Sleep bruxism was more prevalent in children with asthma than controls (47.2% vs. 27.3%, p<0.05). Asthmatics had higher scores of NOT-S total and interview (p<0.05). Dysfunctions on sensory function and chewing and swallowing were more frequent in asthmatics (p<0.05). Salivary cortisol AR on weekend was significantly higher for asthmatics (p<0.05). Salivary cortisol DD was significantly higher on weekday than weekend for controls (p<0.05). There were no significant differences in alpha-amylase values in and between groups.

CONCLUSIONS

The presence of asthma in children was associated with sleep bruxism, negative perception of sensory, chewing and swallowing functions, and higher concentrations of salivary cortisol on weekend.

BOTOX: Broadening the Horizon of Dentistry

Botox has been primarily used in cosmetic treatment for lines and wrinkles on the face, but the botulinum toxin that Botox is derived from has a long history of medically therapeutic uses. For nearly 13 years, until the introduction of Botox Cosmetic in 2002, the only FDA-approved uses of Botox were for crossed eyes (strabismus) and abnormal muscle spasms of the eyelids (blepharospasm). Since then botulinum A, and the seven other forms of the botulinum toxin, have been continuously researched and tested. Botox is a neurotoxin derived from bacterium clostridium botulinm. The toxin inhibits the release of acetylcholine (ACH), a neurotransmitter responsible for the activation of muscle contraction and glandular secretion, and its administration results in reduction of tone in the injected muscle. The use of Botox is a minimally invasive procedure and is showing quite promising results in management of muscle-generated dental diseases like Temporomandibular disorders, bruxism, clenching, masseter hypertrophy and used to treat functional or esthetic dental conditions like deep nasolabial folds, radial lip lines, high lip line and black triangles between teeth.

Sleep-Related Breathing Disorders and Bruxism

Obstructive sleep apnea (OSA) syndrome is a sleep-related breathing disorder, due mainly to peripheral causes, characterized by repeated episodes of obstruction of the upper airways, associated with snoring and arousals. The sleep process fragmentation and oxygen desaturation events lead to the major health problems with numerous pathophysiological consequences. Micro-arousals occurring during sleep are considered to be the main causal factor for night jaw-closing muscles activation called bruxism. Bruxism is characterized by clenching and grinding of the teeth or by bracing or thrusting of the mandible. The causes of bruxism are multifactorial and are mostly of central origin. Among central factors there are secretion disorders of central nervous system neurotransmitters and basal ganglia disorders. Recently, sleep bruxism has started to be regarded as a physiological phenomenon occurring in some parts of the population. In this article we present an evaluation of the relationship between OSA and sleep bruxism. It has been reported that the frequency of apneic episodes and that of teeth clenching positively correlates in OSA. However, clinical findings suggest that further studies are needed to clarify sleep bruxism pathophysiology and to develop new approaches to tailor therapy for individual patients with concomitant sleep bruxism and OSA.

Bruxism is unlikely to cause damage to the periodontium: findings from a systematic literature assessment

BACKGROUND

This paper systematically reviews the MEDLINE and SCOPUS literature to answer the following question: Is there any evidence that bruxism may cause periodontal damage per se?

METHODS

Clinical studies on humans, assessing the potential relationship between bruxism and periodontal lesions (i.e., decreased attachment level, bone loss, tooth mobility/migration, altered periodontal perception) were eligible. Methodologic shortcomings were identified by the adoption of the Critical Appraisal Skills Program quality assessment, mainly concerning the internal validity of findings according to an unspecific bruxism diagnosis.

RESULTS

The six included articles covered a high variability of topics, without multiple papers on the same argument. Findings showed that the only effect of bruxism on periodontal structures was an increase in periodontal sensation, whereas a relationship with periodontal lesions was absent. Based on the analysis of Hill criteria, the validity of causation conclusions was limited, mainly owing to the absence of a longitudinal evaluation of the temporal relationship and dose-response effects between bruxism and periodontal lesions.

CONCLUSIONS

Despite the scarce quantity and quality of the literature that prevents sound conclusions on the causal link between bruxism and the periodontal problems assessed in this review, it seems reasonable to suggest that bruxism cannot cause periodontal damage per se. It is also important to emphasize, however, that because of methodologic problems, particularly regarding sleep bruxism assessment, more high-quality studies (e.g., randomized controlled trials) are needed to further clarify this issue.

Jaw tremor as a physiological biomarker of bruxism

OBJECTIVE

To determine if sleep bruxism is associated with abnormal physiological tremor of the jaw during a visually-guided bite force control task.

METHODS

Healthy participants and patients with sleep bruxism were given visual feedback of their bite force and asked to trace triangular target trajectories (duration=20s, peak force <35% maximum voluntary force). Bite force control was quantified in terms of the power spectra of force fluctuations, masseter EMG activity, and force-to-EMG coherence.

RESULTS

Patients had greater jaw force tremor at ∼8 Hz relative to controls, along with increased masseter EMG activity and force-to-EMG coherence in the same frequency range. Patients also showed lower force-to-EMG coherence at low frequencies (<3 Hz), but greater coherence at high frequencies (20-40 Hz). Finally, patients had greater 6-10 Hz force tremor during periods of descending vs. ascending force, while controls showed no difference in tremor with respect to force dynamics.

CONCLUSION

Patients with bruxism have abnormal jaw tremor when engaged in a visually-guided bite force task.

SIGNIFICANCE

Measurement of jaw tremor may aid in the detection/evaluation of bruxism. In light of previous literature, our results also suggest that bruxism is marked by abnormal or mishandled peripheral feedback from the teeth.

Effect of in vitro chewing and bruxism events on remineralization, at the resin-dentin interface

The purpose of this study was to evaluate if different in vitro functional and parafunctional habits promote mineralization at the resin-dentin interface after bonding with three different adhesive approaches. Dentin surfaces were subjected to distinct treatments: demineralization by (1) 37% phosphoric acid (PA) followed by application of an etch-and-rinse dentin adhesive, Single Bond (SB) (PA+SB); (2) 0.5 M ethylenediaminetetraacetic acid (EDTA) followed by SB (EDTA+SB); (3) application of a self-etch dentin adhesive, Clearfil SE Bond (SEB). Different loading waveforms were applied: No cycling (I), cycled in sine (II) or square (III) waves, sustained loading hold for 24 h (IV) or sustained loading hold for 72 h (V). Remineralization at the bonded interfaces was assessed by AFM imaging/nano-indentation, Raman spectroscopy and Masson's trichrome staining. In general, in vitro chewing and parafunctional habits, promoted an increase of nano-mechanical properties at the resin-dentin interface. Raman spectroscopy through cluster analysis demonstrated an augmentation of the mineral-matrix ratio in loaded specimens. Trichrome staining reflected a narrow demineralized dentin matrix after loading in all groups except in PA+SB and EDTA+SB samples after sustained loading hold for 72 h, which exhibited a strong degree of mineralization. In vitro mechanical loading, produced during chewing and bruxism (square or hold 24 and 72 h waveforms), induced remineralization at the resin-dentin bonded interface.

Bruxism: a literature review

Parafunctional activities associated with the stomatognathic system include lip and cheek chewing, nail biting, and teeth clenching. Bruxism can be classified as awake or sleep bruxism. Patients with sleep bruxism are more likely to experience jaw pain and limitation of movement, than people who do not experience sleep bruxism. Faulty occlusion is one of the most common causes of bruxism that further leads to temporomandibular joint pain. Bruxism has been described in various ways by different authors. This article gives a review of the literature on bruxism since its first description.

Evaluation of Cranio-cervical Posture in Children with Bruxism Before and After Bite Plate Therapy: A Pilot Project

[Purpose] The aim of the present study was to evaluate the effect of a biteplate on the cranio-cervical posture of children with bruxism. [Subjects and Methods] Twelve male and female children aged six to 10 years with a diagnosis of bruxism participated in this study. The children used a biteplate during sleep for 30 days and were submitted to three postural evaluations: initial, immediately following placement of the biteplate, and at the end of treatment. Posture analysis was performed with the aid of the Alcimagem^® 2.1 program. Data analysis (IBM SPSS Statistics 2.0) involved descriptive statistics and the Student’s t-test. [Results] A statistically significant difference was found between the initial cranio-cervical angle and the angle immediately following placement of the biteplate. However, no statistically significant difference was found between the initial angle and the angle after one month of biteplate usage. [Conclusion] No significant change in the cranio-cervical posture of the children was found one month of biteplate usage. However, a reduction occurred in the cranio-cervical angle when the biteplate was in position.

Diagnosis and management of occlusal wear: a case report

The rationale for doing full mouth rehabilitation are, when occlusal forces become traumatic hampering the health of periodontal tissues, extensive occlusal diseases, trauma, temporomandibular joint disease and congenital disorders with malformed dentition. Literature exposes that full mouth fixed rehabilitation is one of the taxing procedures in the field of Prosthodontics. A critical aspect for successful occlusal rehabilitation is to determine the aetiology, correct sequence of treatment and most importantly the occlusal vertical dimension and centric relation in which to plan the treatment. A systematic approach in managing these patients can lead to a predictable and favourable prognosis. This article presents the stages of prosthodontic rehabilitation, from diagnosis to final treatment and follow-up, of a bruxer patient with severely worn dentition.

Trial of oral metoclopramide on diurnal bruxism of brain injury

Bruxism is a diurnal or nocturnal parafunctional activity that includes tooth clenching, bracing, gnashing, and grinding. The dopaminergic system seems to be the key pathophysiology of bruxism and diminution of dopaminergic transmission at the prefrontal cortex seems to induce it. We report two patients with diurnal bruxism in whom a bilateral frontal lobe injury resulted from hemorrhagic stroke or traumatic brain injury. These patients' bruxism was refractory to bromocriptine but responded to low-dose metoclopramide therapy. We propose that administering low doses of metoclopramide is possibly a sound method for treating bruxism in a brain injury patient with frontal lobe hypoperfusion on positron emission tomography imaging.

Environmental factors, sleep duration, and sleep bruxism in Brazilian schoolchildren: a case-control study

OBJECTIVE

The purpose of our study was to evaluate the association between environmental factors, sleep duration, and sleep bruxism (SB) in schoolchildren.

METHODS

A case-control study was performed. Individuals participating in the study were randomly chosen from public and private schools in Belo Horizonte, Brazil. A total of 120 children with bruxism and 240 without bruxism (mean age, 8 years) participated in our study. A questionnaire for parents was used to collect data based on criteria taken from the American Academy of Sleep Medicine. Conditional binary logistic regression statistical tests and χ2 tests were used for analysis.

RESULTS

The final logistical model found that children with a median sleep time < or = 8 h per night (odds ratio [OR], 2.561 [95% confidence interval {CI}, 1.480-4.433]), who did not enjoy a good night's sleep (OR, 3.253 [95% CI, 1.600-6.615]), who slept with noise in the room (OR, 2.699 [95% CI, 1.645-4.429]), and who had the light on (OR, 2.370 [95% CI, 1.446-3.884]), were more likely to have SB.

CONCLUSION

Children who sleep for less than 8h a night are more likely to have SB. Light and noise in the room were two predisposing factors for the occurrence of SB.

Co-activation of jaw and neck muscles during submaximum clenching in the supine position

OBJECTIVE

The purpose of this study was to test the hypothesis that jaw clenching induces co-contraction and low-level long-lasting tonic activation (LLTA) of neck muscles in the supine position.

DESIGN

Ten healthy subjects developed various feedback-controlled submaximum bite forces in different bite-force directions in supine position. The electromyographic (EMG) activity of the semispinalis capitis, semispinalis cervicis, multifidi, splenius capitis, levator scapulae, trapezius, sternocleidomastoideus, masseter and infra/supra-hyoidal muscles was recorded. For normalization of EMG data, maximum-effort tasks of the neck muscles were performed.

RESULTS

Co-contractions of the posterior neck muscles varied between 2% and 11% of their maximum voluntary contraction. Different bite forces and bite-force directions resulted in significant (p<.05) activity differences between the co-contraction levels of the neck muscles. In addition, LLTA of specific neck muscles, provoked by the jaw clenching tasks, was observed.

CONCLUSIONS

This study demonstrated for the first time moderate co-contractions of jaw and neck muscles in the supine position under controlled submaximum jaw clenching forces. LLTA of most neck muscles was observed, outlasting clenching episodes and indicating an additional neuromuscular interaction between the two muscle groups.

Computerized analysis of occlusal contacts in bruxism patients treated with occlusal splint therapy

PURPOSE

Occlusal splints are commonly used to prevent tooth wear caused by bruxism. However, the effects of splints on occlusion are still unclear. Although it is rarely alluded in literature, splints can provoke severe occlusal alterations and other complications. This study was aimed to identify differences in the responses of individuals with bruxism and healthy individuals to a full-arch maxillary stabilization splint in terms of occlusal changes.

MATERIALS AND METHODS

Occlusal contacts in 20 (5 male, 15 female) bruxism patients and 20 (5 male, 15 female) controls with normal occlusion were evaluated before and after occlusal splint therapy. T-Scan III, a computerized occlusal analysis system, was used to simultaneously measure occlusion and disclusion times as well as left-right and anterior-posterior contact distributions before splint therapy and 3 months after therapy. Wilcoxon and Mann-Whitney U tests were used for statistical analyses (α=.05).

RESULTS

No differences were found in the posterior contact of bruxism patients before and after stabilization splint treatment. However, differences in posterior contact were observed between bruxists and normal individuals prior to treatment, and this difference disappeared following treatment.

CONCLUSION

The results of this study showed the use of a stabilization splint may not have an effect on occlusion. However, the area of posterior occlusal contact among bruxists was found to be greater than that of normal individuals. According to this study, the clinical use of splints may be harmless.

Relationship between Bruxism and Malocclusion among Preschool Children in Isfahan

BACKGROUND AND AIMS

Bruxism is defined as a habitual nonfunctional forceful contact between occlusal tooth surfaces. In younger children bruxism may be a consequence of the masticatory neuromuscular system immaturity. The aim of this study was to assess the prevalence of bruxism and investigate the relationship between occlusal factors and bruxism among preschool children.

MATERIALS AND METHODS

In this cross-sectional survey, 400 3-6-year-old children were selected randomly from different preschools in Isfahan, Iran. The subjects were divided into two groups of bruxers and non-bruxers as determined by the clinical examination and their parents' reports. The examiner recorded the primary canines (Class I, Class II, and Class III) and molars (mesial step, distal step, flash terminal plane) relationship, existence of anterior and posterior crossbite, open and deep bite. Also, rotated teeth, food impaction, sharp tooth edges, high restorations, extensive tooth caries, and painful teeth (categorized as irritating tooth conditions) were evaluated. The relationship between bruxism and occlusal factors and irritating tooth conditions was evaluated with chi-square test.

RESULTS

Bruxism was seen in 12.75% of the subjects. Statistically significant relationships existed between bruxism and some occlusal factors, such as flash terminal plane (P = 0.023) and mesial step (P = 0.001) and also, between food impaction, extensive tooth caries, tooth pain, sharp tooth edge and bruxism.

CONCLUSION

The results showed significant relationship of bruxism with primary molar relationships and irritating tooth conditions among preschool children.

Outcomes of management of early temporomandibular joint disorders: How effective is nonsurgical therapy in the long-term?

AIM

The first step in the management of Temporomandibular Disorders (TMD) is usually noninvasive, especially if the disorder is in the early stages. Clinically, pain and clicking are early signs and symptoms of TMD. The management of TMD usually includes "splint therapy" and analgesics. In this study, we report our long-term outcomes in the treatment of patients suffering from early TMD.

MATERIALS AND METHODS

We assessed the records of 138 patients who were referred for management of TMD. Selection was based on pain and/or clicking of the Temporomandibular Joint (TMJ), no pathologic lesions of the TMJ, no anterior disc displacement without reduction (closed lock), no Degenerative Joint Disease, no history of migraine, trauma, osteoarthritis, metabolic disease, or malocclusion (deep bite, cross bite, jaw deformity, etc). The patients were treated with an acrylic maxillary Interocclusal Splint (IOS) cuspid-rise type and were told to refrain from biting, yawning and chewing hard food. The outcome of the treatment, potential etiologic factors (Bruxism), signs and symptoms and patient demographics (such as age, sex, treatment duration, etc.) were assessed. The data were analyzed using the Chi-square test to correlate significance.

RESULTS

One hundred thirty-eight patients (26 males and 112 females) with early signs and symptoms of TMD (pain and/or click of the TMJ) were treated from 2001 to 2010; 81% were females and 19% were males. All the 138 patients used the IOS at night only. The patients were followed-up for 1-9 years. Data analysis showed that 64% of the patients were completely relieved of signs and symptoms; 22% were moderately relieved (decreased severity of signs and symptoms) and 14% had no noticeable post-treatment changes in clicking or pain (P = 0.001). Patients with bruxism and those presenting with both pain and clicking showed a better response to IOS treatment (P = 0.046 and P = 0.001, respectively). The results also showed that age, sex, severity of symptoms and duration of the treatment did not influence treatment results in this group of patients with early TMD.

CONCLUSION

In this population, TMD was significantly higher in females. Treatment of early TMD with IOS was effective and moderately effective in long-term in over 80% of the patients during the follow-up period of 1-9 years. Bruxism had a significant etiologic role in TMD; occlusal attrition of the dentition, pain of all the teeth, early morning pain of the masticatory muscles and the TMJ are signs and symptoms to suspect nocturnal bruxism. Use of an IOS is recommended to prevent potential damage to the dentition, periodontium and the TMJ in early TMD.

Effect of occlusal splints on the temporomandibular disorders, dental wear and anxiety of bruxist children

OBJECTIVES

To evaluate the effectiveness of occlusal splints to reduce the signs and symptoms of temporomandibular disorders (TMD), dental wear and anxiety in a group of bruxist children.

METHODS

All of the subjects were 3 to 6 years old, had complete primary dentition, class I occlusion and were classified as bruxist according to the minimal criteria of the ICSD for bruxism. For each child, anxiety was evaluated with the Conners' Parent Rating Scales (CPRS). The TMD were evaluated using the RDC/TMD. The dental wear was processed in digital format with Mat Lab® and Lab view® software to determine its size and form. The children were randomized into an experimental (n=19) and a control (n=17) group. The children in the experimental group used rigid bite plates for a two-year period, until mixed dentition. Afterwards, the CPRS and the RDC/TMD were applied again and dental casts were taken. Comparisons of the variables regarding dental wear, signs and symptoms of TMD and anxiety before and after treatment among the groups were analyzed using the t-test, the Wilcoxon rank sum test and the Mann-Whitney test.

RESULTS

The subjects in the experimental group showed no statistically significant difference regarding anxiety levels and dental wear when compared with the control group. The signs and symptoms of TMD were not reduced except for the deviation in mouth opening.

CONCLUSIONS

The use of rigid occlusal bite plates was not efficient in reducing the signs of bruxism as a whole but did reduce the deviation in mouth opening.

A Study on Prevalence of Dental Attrition and its Relation to Factors of Age, Gender and to the Signs of TMJ Dysfunction

A study was planned to determine the severity of dental attrition in adults of both sexes in different age groups and its possible relationship to temporomandibular disorders. 500 subjects comprising of 260 females and 240 males in the age group of 18-55 years were clinically examined for bruxism, attrition, and signs of temporomandibular disorders. Tooth sensitivity, tooth or restoration fracture, scalloping of tongue, ridging of buccal mucosa, TMJ sounds, muscle tenderness, TMJ tenderness, referred pain, pain on mouth opening and limitation of mouth opening were recorded along with attrition score in a proforma. The basic data was then analysed to arrive at certain conclusions. A high prevalence of attrition (88.0%) with increase in age (P < 0.00) and was seen more in males as compared to females (P < 0.01). On comparing attrition with some of the signs of bruxism it was shown that tooth or restoration fracture and scalloping of tongue had no relation to the severity of attrition score. Whereas a significant relation was seen between attrition and tooth sensitivity (P < 0.00), and ridging of buccal mucosa (P < 0.05). Muscle tenderness (P < 0.00), pain on mouth opening (P < 0.05) and deviation of mandible on mouth opening (P < 0.00) had significant relation to attrition. Other signs of temporomandibular disorders such as joint tenderness, referred pain, joint sounds and limitation of mouth opening had no relation to attrition score. This study showed a limited association between the severity of attrition and TMJ dysfunction.

The Prevalence of Bruxism and Correlated Factors in Children Referred to Dental Schools of Tehran, Based on Parent's Report

OBJECTIVE

Bruxism is defined as the habitual nonfunctional forceful contact between occlusal tooth surfaces. The aim of this study was to determine the prevalence of bruxism and correlated factors in children referred to dental schools of Tehran, based on Parent's report.

METHODS

This cross-sectional descriptive study was conducted on 600 4-12 year-old children with a mean age of 7.4±2.4 years, who were referred to four dental schools in Tehran. After collecting information with questionnaire filled out by parents, χ(2), Fisher Test, Mann-Whitney and t-Test were used to analyze the data.

FINDINGS

The prevalence of bruxism was 26.2%. Bruxism begun in average at the age of 4.9±2 years. Also it occurred 2.6 times more in children who had a family history of bruxism (father-mother), compared to children who didn't have such a history. 87% of children with bruxism had a history of distressing events in their life, and 13% of children with bruxism did not report any history of distressing events in their life. In this study most common oral habit was nail biting. In study of parasomnias, drooling was the most, and snoring the least reported sleep disorder. Bruxism in children with drooling was twice more than in other children. The prevalence of bruxism in children with temporomandibular disorder was 63.6% and in children without TMD was 24.7%.

CONCLUSION

Based on Parent's report, 26.2% of children showed bruxism and there was a significant relation between bruxism and mother's job, family history, distressing event in life, parasomnias, especially drooling and sleep walking, TMD, hyperactivity, depression, acrophobia and lygophobia.

The Correlation between Intestinal Parasitic Infections and Bruxism among 3-6 Year-Old Children in Isfahan

BACKGROUND

Given the fact that bruxism is a prevalent oral habit among children and a potential destructor of oral tissues, the present study aimed to investigate the relationship between intestinal parasitic infections and bruxism among kindergarten children.

METHODS

Questionnaires were administered among parents of kindergarten children in Isfahan to select 50 children identified by their parents to have the habit of bruxism and 50 without the habit as control group. Informed consent was obtained prior to the investigation. Parents were delivered sampling instruments with proper instructions to collect stool samples from both groups for parasitological tests. The diagnostic parasitological tests involved the direct stool smear, formol-ether concentration, and Scotch tape tests. Comparison for the frequency distribution of intestinal parasitic infections between the two groups was performed using the chi-square test (α = 0.05).

RESULTS

Parasitic infections were observed in 19 (11/50 cases and 8/50 controls) children. A statistically significant relationship was observed between infection with pathogenic parasites and bruxism (P < 0.05).

CONCLUSION

Our findings suggest that pathogenic parasites may serve as the cause of initiation of bruxism habits among children.

The use of zirconium and feldspathic porcelain in the management of the severely worn dentition: a case report

The management of the interim phase of a complete oral rehabilitation in patients with severely worn dentition is often challenging due to the loss of occlusal vertical dimension, loss of tooth structure, uneven wear of teeth creating an uneven plane of occlusion, and parafunctional habits. This case report describes the management of excessive tooth tissue loss in a 45 year old woman with a history of bruxism, esthetical complaints in anterior teeth, and impaired dental function due to reduced tooth height. The patient used occlusal splint for a month and than resection of the alveolar bone was performed on the vestibular sides of the maxillary anterior teeth, except the interdental alveolar crest. Maxillary anterior teeth were restored with zirconia porcelain. Feldspathic porcelain was chosen to restore remaining teeth in both jaws; the patient also was given an occlusion guard to protect the restoration against future bruxism. Regardless of the cause of occlusal instability, it is important that the restorative dentist should be able to recognize its signs such as tooth hypermobility, tooth wear, periodontal breakdown, occlusal dimpling, stress fractures, exostosis, muscle enlargement, and loss of posterior disclusion. When restoring the worn dentition, the clinician should bear in mind the five P's: proper planning prevents poor performance.

Evaluation of Treatments in Patients with Nocturnal Bruxism on Bite Force and Occlusal Contact Area: A preliminary report

OBJECTIVES

The purpose of this study was to investigate the short-term effects of occlusal splint therapy and tricyclic antidepressants on the bite force and occlusal contact area of patients presenting with nocturnal bruxism.

METHODS

A maxillary full-coverage hard acrylic splint was applied to the five patients (Group S). Five patients took a tricyclic antidepressant (Amitriptiline HCl, 10 mg/day) for 3 months (Group A) and a control group (Group C) comprising of 10 dental school students with normal occlusion was also formed. Using a Dental Prescale (Fuji Photo Film Corporation, Tokyo, Japan) and an Occluzer computer (FPD703, Fuji Photo Film Corporation, Tokyo, Japan) the bite force and occlusal contact area were measured. The evaluations were made just before the treatment and at 1 month and 3 months of treatment.

RESULTS

The bite force and occlusal contact area before treatment in study Groups A and S were found to be higher than those in the Group C. Furthermore, the bite force and occlusal contact area increased during treatment in Group A whilst they decreased in Group S. Bite force and occlusal contact area in Group S were lower at both 1 month and 3 months of treatment than in Group C.

CONCLUSIONS

It could be tentatively suggested that occlusal splint therapy may be more effective than tricyclic antidepressant in the treatment of bruxism. Further investigations of this measurement method involving larger study populations and a longer follow-up period are needed.

Delayed-onset continuous bruxism with olivary hypertrophy after top of the basilar syndrome

Delayed-onset continuous bruxism due to brain stem infarction has not yet been reported. A 49-year old man presented with quadriplegia and ophthalmoplegia. Brain MRI showed acute infarction in the bilateral midbrain, right thalamus and the superior cerebellum. One month later, the patient developed bruxism which persisted during sleep. A palatal myoclonus was not observed. Follow up MRI taken 4 months later showed bilateral olivary hypertrophy. We suggest that the patient's bruxism may be related to the olivary hypertrophy. The bruxism generator may be located in the pontine-reticular-formation (PRF). Bilateral large midbrain lesions interrupting the cortical inhibition may have produced bilateral olivary hypertrophy, which could stimulate the PRF, producing continuous bruxism.

Bruxism: A factor associated with temporomandibular disorders and orofacial pain

Rhythmic masticatory muscle activities are probably part of normal jaw motor behavior. Certain factors, like disease, stress, personality, alcohol, and medication, may turn this normal activity into a condition that might include abnormal tooth wear, myofascial pain, and temporomandibular joint problems. This condition then corresponds with bruxism. Bruxism and masticatory muscle pain may reciprocally influence one another: although not a compulsory finding, bruxism may be associated with the predisposition, initiation, and perpetuation of temporomandibular disorders and orofacial pain. On the other hand, the presence of jaw muscle pain may reduce bruxism motor activity. Research on the integrity and nature of the relationship between bruxism and pain is hampered by controversies that exist regarding definition, diagnostic criteria, and measurement techniques. Moreover, the pathophysiology of bruxism and its association with other sleep-related and movement disorders are still unclear. Consequently, there is no real cure for bruxism, although several treatments may be used to control its adverse effects. However, there is very limited research to support the efficacy of behavioral, physical, dental, pharmacological, and orthopedic treatments. Probably the best current treatment modality for bruxism is the occlusal stabilization splint. Although such an orthopedic device may not actually prevent bruxism, it may help to reduce its symptoms.

Systemic ligament hypermobility in temporomandibular disorders

Systemic ligament hypermobility (benign hypermobile joint syndrome or BHJS) and masticatory parafunction (clenching/bruxism) were evaluated in intracapsular TMD (n=110) and non-TMD (n=112) populations. Individuals that had a ligament mobility index greater than four were classified as benign hypermobile joint syndrome (BHJS) utilizing the modified Carter-Wilkinson systemic ligament hypermobility scale. All subjects in the TMD and control groups were female, between the ages of 10 and 79 with Angles' Class I molars and cuspids. This study found Benign Hypermobile Joint Syndrome (BHJS) and masticatory parafunction, when present simultaneously in females, to be significantly associated with intracapsular TMD symptoms (P<0.001).