MR sialographic assessment of the masseter muscle and the ductal kinking in patients with recurrent parotitis.

Dysfunction of the masseter muscle may cause pathological kinking of the parotid duct leading to parotitis; MR sialography is a non-invasive radiological examination that allows to evaluate dynamically the ductal system of the parotid glands. In the present study we aimed to assess the relationships between Stensen's duct and masseter muscle and their implications in the aetiopathogenesis of recurrent parotitis secondary to masseter muscle dysfunction. Forty-one patients with recurrent unilateral parotitis and nine with bilateral recurrent parotitis, all with a clinical suspicious of masseter muscle hypertrophy due to bruxism were enrolled. They underwent ultrasonography as a first line examination and then MR sialography and sialendoscopy. Different anatomical features were studied. Involved parotid glands had a wider duct compared to contralateral unaffected parotid glands of patients with recurrent parotitis (p = 0.00134); male subjects with parotitis had a longer duct compared to the salivary glands of healthy patients (p = 0.00943 for affected glands and p = 0.00629 for the contralateral). A concordance between the evidence of an acute duct angle during sialendoscopy and a wider duct in patients with parotitis was observed although not statistically significant. These initial findings suggest that the masticatory muscle dysfunction related to bruxism seems to condition alteration of parotid duct course and anatomy thus favouring the occurrence of recurrent parotitis. A specific diagnostic iter based on clinical evaluation, dynamic ultrasonography and MR sialography, is therefore, mandatory to confirm the relationship between masseter muscle anatomy and parotid duct anomalies; this is the premise for an adequate therapeutic approach to underlying masticatory muscle disorder.

Morphological evaluation of gonial and antegonial regions in bruxers on panoramic radiographic images.

BACKGROUND: This is the first study to report both cortical and trabecular bone evaluation of mandibles in bruxers, within the knowledge of the authors. The purpose of this study was to evaluate the effects of bruxism on both the cortical and the trabecular bone in antegonial and gonial regions of the mandible, which is the attachment of the masticatory muscles, by using panoramic radiographic images. METHODS: In this study, the data of 65 bruxer (31 female, 34 male) and 71 non-bruxer (37 female, 34 male) young adult patients (20-30 years) were evaluated. Antegonial Notch Depth (AND), Antegonial-Index (AI), Gonial-Index, Fractal Dimension (FD) and Bone Peaks (BP) were evaluated on panoramic radiographic images. The effects of the bruxism, gender and side factors were investigated according to these findings. The statistical significance level was set atP ≤ 0.05. RESULTS: The mean AND of bruxers (2.03 ± 0.91) was significantly higher than non-bruxers (1.57 ± 0.71; P < 0.001). The mean AND of males was significantly higher than females on both sides (P < 0.05). The mean AI of bruxers (2.95 ± 0.50) was significantly higher than non-bruxers (2.77 ± 0.43; P = 0.019). The mean FD on each side was significantly lower in bruxers than in non-bruxers (P < 0.05). The mean FD of males (1.39 ± 0.06) was significantly higher than females (1.37 ± 0.06; P = 0.049). BP were observed in 72.5% of bruxers and 27.5% of non-bruxers. The probability of existing BP, in bruxers was approximately 3.4 times higher than in non-bruxers (P = 0.003), in males was approximately 5.5 times higher than in females (P < 0.001). CONCLUSION: According to the findings of this study, the morphological differences seen in cortical and trabecular bone in the antegonial and gonial regions of the mandible in bruxers can be emphasized as deeper AND, higher AI, increased of existing BPs, and lower FD, respectively. The appearance of these morphological changes on radiographs may be useful for indication and follow-up of bruxism. Gender is an effective factor on AND, existing BP and FD.

Evaluation of the thickness and internal structure of the masseter muscle with ultrasonography in female bruxism patients.

OBJECTIVES: The aim of this study was to evaluate the differences in the thickness and internal structure of the masseter muscle in individuals with and without bruxism by ultrasonography. MATERIALS AND METHODS: A total of 60 female patients with and without bruxism whose ages were ranging between 20 and 35 were included in the study. The masseter muscle thickness was measured during rest and maximum bite position. Ultrasonographic internal structure of the masseter muscle is classified according to the visibility of echogenic bands. In addition, the echogenic internal structure of the masseter muscle was evaluated with quantitative muscle ultrasound. RESULTS: The masseter muscle thickness was significantly higher in both positions in patients with bruxism (p < 0.05). There was no significant difference between two groups in the evaluation of echogenicity (p > 0.05). CONCLUSIONS: Ultrasonography is a useful and important diagnostic method for evaluating masseter muscle without using radiation.

The usefulness of quantitatively assessing temporomandibular joint disk stiffness with shear wave elastography in adolescents with bruxism.

OBJECTIVE: The objectives of this study were to quantitatively measure temporomandibular joint (TMJ) disk stiffness in adolescents with bruxism using shear wave elastography (SWE) and to examine the relationship between elastography values, patient age, and duration of bruxism. STUDY DESIGN: This prospective study evaluated 120 TMJ disks of 60 adolescents (30 patients with bruxism and 30 controls). The stiffness of the anterior, intermediate, and posterior parts of the disk was measured. The patient and control groups' respective quantitative SWE values of elasticity (kilopascals [kPa]) and velocity (meters/second [m/s]) were compared. RESULTS: The elasticity and velocity values of the anterior and intermediate parts were significantly higher in the patients than in the controls (P ≤ .013), with no significant difference in the size of the joint space (P = .886). A receiver operating characteristic analysis resulted in sensitivity for the anterior part of 0.80 for kPa and 0.83 for m/s, with specificity of 0.57 (kPa) and 0.60 (m/s). For the intermediate part, the sensitivity was 0.80 for kPa and 0.86 for m/s, with specificity of 0.64 (kPa) and 0.57 (m/s). No correlations were found between the SWE values and patient age (P ≥ .098) or duration of bruxism (P ≥ .134). CONCLUSIONS: SWE may be useful in the evaluation of TMJ disk stiffness in patients with bruxism.

Bone apposition at the mandibular angles as a radiological sign of bruxism: a retrospective study.

BACKGROUND: The main objective of this investigation was to determine on panoramic radiographs the prevalence of macroscopically visible alterations (bone apposition in combination with directional change) in the mandibular angle region in bruxism patients. Another aim was to describe and detect different morphological characteristics of the jaw angles. METHODS: Two hundred panoramic radiographs were studied: 100 images of adults with clinically diagnosed bruxism (73 women, 27 men, age range 21-83 years), 100 images of a comparison group consisting of adolescents (66 girls, 34 boys, age range 12-18 years). RESULTS: The morphological changes of the 400 jaw angles could be classified into four degrees. In the adult group, almost half of mandibular angles showed bone apposition. Conversely, the prevalence in the control group was zero. The localization of the appositions corresponds to the insertions of the masseter and medial pterygoid muscles at the mandibular angle. CONCLUSIONS: The bone apposition at the mandibular angles should be interpreted as a functional adaptation to the long-term increased loads that occur during the contraction of the jaw closing muscles due to bruxism. Hence, radiologically diagnosed bone apposition may serve as an indication or confirmation of bruxism.

Tratamiento del bruxismo con toxina botulínica tipo A. Estudio clínico prospectivo / Bruxism treatment with botulinum toxin type A. Prospective clinical study

Introducción y objetivo: El bruxismo (BRX) se define como rechinar y/o apretar los dientes, involuntaria e intensamente, debido a hipertrofia y/o contracción reiterada de los músculos masticatorios, especialmente los maseteros. Puede suceder durante el sueño o de día indistintamente. Los tratamientos empleados tienen la finalidad de limitar el daño sobre diferentes estructuras biológicas, especialmente la articulación témporo-mandibular (ATM), y oscilan desde oclusión irreversible, interposición de férulas, tratamiento farmacológico y/o terapias cognitivas, así como el empleo de toxina botulínica tipo A (TB-A). El objetivo de nuestro estudio fue investigar el efecto de relajación inducido por la inyección de TB-A en los maseteros y su relación con el alivio de los síntomas referidos por los pacientes con BRX. Material y método. Estudio clínico, prospectivo y longitudinal en 25 pacientes, mujeres, de 24 a 67 años (37.2 ± 10.7), desde setiembre de 2018 a marzo de 2019.Los controles de evaluación se realizaron antes, 2 semanas y 4 meses después del tratamiento con TB-A. Se tomaron fotografías digitales, se valoró el índice de desgaste dental de Smith-Knigth y se realizó ortopantomografía. Algunas pacientes aportaron resonancia magnética nuclear. Se tomaron medidas del diámetro bigonial mediante calibre digital y se valoró el grosor de los maseteros en reposo y contracción, por medición ecográfica. Resultados: Después del tratamiento con TB-A, el 24% de las pacientes se vieron libres de BRX y el 76% restante obtuvo gran mejoría; hubo escasos y transitorios efectos adversos. Conclusiones: La TB-A protege las estructuras orofaciales (dientes, músculos mandibulares, ATM) del daño inducido por el BRX, al tiempo que alivia el dolor y los síntomas relacionados con la excesiva contracción muscular

Background and objective: Bruxism (BRX) is defined as grinding or clenching of teeth, involuntarily and intensely, due to hypertrophy and/or contraction of muscles related to chewing, with particular involvement of masseters. It can happen during sleep or wakefulness indistinctly. Treatments are intended to limit destructive effects of BRX on different biological structures, especially the temporomandibular joint; are variable and range from irreversible occlusion, interposition of splints, pharmacological therapies, cognitive-behavioral approaches and the use of botulinum toxin type A (BoNT-A). The aim of this study was to investigate the relaxation effect of BoNT-A injection in masseter muscles and its relation to relief of symptoms in patients with BRX. Methods: This study is a clinical, prospective and longitudinal trial on 25 adult female patients between age ranges 24 to 67 (3.,2 ± 10.7), carried out from September 2018 to March 2019.Evaluation controls were done before, 2 weeks and 4 months after treatment with BoNT-A. Examination protocol in the trial included digital photography, Smith and Knight tooth wear index, orthopantomogra- phy and magnetic resonance imaging. Measurements of bigonial diameters were taken by calliper, at rest and during contraction, and the thickness of each masseter muscle was also evaluated in the same conditions, by ultrasound at every control. Results.As a result, after BoNT-A treatment, 24% of the patients were free of BRX, while the remaining 76% obtained a significant improvement, with few and transient adverse effects. Conclusions: BoNT-A can be used to protect oral-facial structures (such as teeth, jaw muscles, temporomandibular joint), from excessive forces and harmful damage caused by BRX, and to relieve accompanying pain and related complaints by decreasing the muscle forces exerted during contraction

Trastornos de sueño asociados a bruxismo de sueño en niños entre 3 y 6 años de edad atendidos en la Clínica Odontológica de la Universidad Mayor de Santiago, Chile / Sleep disorders associated with sleep bruxism in children between 3 and 6 years old attended at the Dental Clinic of the University Mayor of Santiago, Chile

El bruxismo se define como una actividad repetitiva de los músculos masticatorios caracterizada por el apriete o rechinamiento dentario, y/o la tensión o desplazamiento de la mandíbula. 1 Éste tiene dos manifestaciones circadianas: Puede ocurrir durante el sueño (BS) o durante vigilia. 2 En niños, el método clínico más confiable para diagnosticarlo sigue siendo el basado en el reporte de rechinamiento por parte de sus padres o cuidadores; sin embargo, la mayoría de los niños duermen lejos de los padres. 3 Existe una dificultad diagnóstica para poder establecer la pérdida de estructura dentaria por bruxismo en niños, ya que se debe diferenciar del desgaste fisiológico que se produce en los dientes temporales. Hay una serie de trastornos de sueño, catalogados por la Clasificación Internacional de Trastornos del Sueño. 4 que se han asociado al BS. 5 , 6 , 7 El objetivo de este estudio fue establecer si existe asociación entre BS y determinados trastornos de sueño en preescolares. Se evaluaron 100 niños de la Clínica Odontológica de la Universidad Mayor de Santiago, Chile, de edades entre 3 y 6 años, mediante evaluación clínica y anamnesis consultada a padres o tutores para determinar la presencia de BS, además de encuesta "Escala de Alteraciones del Sueño en la Infancia, para preescolares". El estudio mostró una prevalencia de BS de un 47%, sin diferencia entre hombres y mujeres y una asociación de algunos de los trastornos del sueño con BS (Parasomnias, Problemas Respiratorios, Hiperhidrosis y Sueño no reparador). Como conclusión sí existe asociación entre trastornos de sueño y BS

Bruxism is defined as a repetitive activity of the chewing muscles characterized by grinding and clenching the teeth, and / or tension or displacement of the jaw 20 . This one has two circadian manifestations: It can occur during sleep (BS) or during wakefulness 12 . In children, the most reliable clinical method to diagnose is still based on the report of grinding by their parents or caregivers; however, most children sleep away from parents 10 . There is a diagnostic difficulty in establishing the loss of tooth structure due to bruxism in children, since it must be differentiated from the physiological wear that occurs in the temporary teeth. There are some sleep disorders, cataloged by the International Classification of Sleep Disorders 41 that have been associated with BS 6 , 17 ,31. The objective of this study was to establish whether there is an association between BS and sleep disorders in preschoolers. 100 children in the Odontological Clinic of the Universidad Mayor of Santiago, Chile, between 3 and 6 years old were evaluated, through clinical evaluation and anamnesis consulted to parents or guardians to determine the presence of BS, in addition to the survey "Scale of Sleep Disorder in Childhood, for preschoolers " The study showed a prevalence of BS of 47%, with no difference between boys and girls, and an association of some of the sleep disorders with BS (Parasomnias, Respiratory Problems, Hyperhidrosis and Not Restful Sleep). As a conclusion, there is an association between sleep disorders and BS

STXBP1 encephalopathy is associated with awake bruxism.

Heterozygous mutations in syntaxin-binding protein 1 (STXBP1) gene are associated with early infantile epileptic encephalopathy 4 (EIEE4). This condition is characterized by epilepsy, developmental delay (DD), and various movement disorders. Herein, we will report 5 unrelated patients with different de novo mutations in STXBP1. In addition, we conducted an online survey through Facebook to identify the incidence of bruxism (BRX) in these patients. Four out of 5 patients (80%) presented with awake BRX (A-BRX). Bruxism was also reported in 81.4% (57/70) of the patients with STXBP1 encephalopathy through the online questionnaire. No consistent correlation was identified between the type of mutation and development of movement disorders or BRX. This is the first study to demonstrate A-BRX in patients with STXBP1 mutation. Given the role of STXBP1 in exocytosis of neurotransmitters and other manifestations of dopamine dysregulation in patients with STXBP1-EIEE4, we suggest that in patients with STXBP1 encephalopathy, A-BRX might be the result of the involvement of dopaminergic circuits.

Microstructural investigation of masticatory muscles: a pre- and post-treatment diffusion tensor imaging study in a bruxism case.

We evaluated, by means of a non-invasive procedure based on MRI, the masticatory muscular microstructure in a 55-year-old-female patient affected by bruxism. The patient underwent MR examination before and after 1 month of splint therapy, when she mentioned the complete disappearance of all symptoms. By means of diffusion tensor imaging we observed changes at microstructural level of masticatory muscular complex. We conclude that diffusion tensor imaging may be a useful instrument both to perform panoramic reconstruction of the masticatory muscle complex and to investigate microstructural modifications related to the pain relief in bruxism.

Mandibular condylar morphology for bruxers with different grinding patterns.

OBJECTIVES: The purpose of this study was to investigate the mandibular condylar morphology for bruxers with different grinding patterns. METHOD: Condylar sectional morphology and condylar position of 30 subjects were determined by two viewers using cone beam computed tomography (CBCT) image data sets. The grinding patterns during sleep bruxism (SB) were determined objectively using a Brux-checker device.Chi-square tests were used for statistical analysis for the condylar morphology type between different tooth grinding patterns. Spearman's rank correlation coefficient was used for correlation analysis between condylar position and the canine guidance area during SB. RESULTS: Theincidence of condylarmorphologicaldivergence from idealwas35%.There isa significant difference in distribution of condylar morphology type between the group grinding (GG) and GG combined with mediotrusive side grinding (MG) (p < 0.05). There was no significant correlation between condylar position and canine guidance area during bruxism. DISCUSSION: MG during SB is associated with condylar morphology that is considered not to be ideal.

Generation of 3D thermal models for dentistry applications.

There are a variety of medical imaging modalities available, although each modality focus into different aspects, for example: anatomical, physiological or geometrical information. This paper presents a new imaging modality (3D THERMO-SCAN) that combines anatomical computer tomography (CT) imaging slices, together with 2D infrared thermography images and 3D scanned shaped models of the area under study. Therefore, it is presented the 3D reconstructions involving a case study of a volunteer with bruxism. Some characteristics of bruxism are the hyperactivity of the chewing muscles, which changes the dynamics of microcirculation, also changing the correspondent skin's temperature. The emphasis is to show the corresponding structures, such as jaw/mandibular region that will produce either decrease or increase in temperature, which are related to bruxism and the associated use of an occlusal splint, respectively.

Bruxism--before and after images--on 18F-FDG PET/CT.

Physical activity before F-FDG PET/CT can cause increased muscle glucose metabolism. We report markedly increased glucose metabolism in the masseter and temporalis muscles of a 53-year-old man who was clenching his teeth before the scan, and then resolution of this increased metabolism on a second scan 12 weeks later. SUVmax in the right masseter muscle was 26.9; 12 weeks later, the SUVmax was 1.6. This level of FDG uptake in bruxism has not yet been reported.

Imaging bruxism.

A 62-year-old woman was referred for SPECT brain blood flow study with a diagnosis of possible dementia or depression. Findings within the brain were noncontributory, but extraneous structures with high blood flow were detected within the soft tissues of temporal regions and face. On questioning, the patient stated that she had sleep bruxism, with gnashing and grinding of her teeth. This did not occur during waking. Bruxisms and its consequences, with effects on the teeth and jaws, are a problem of importance to oral surgeons and dentists. There is considerable active research into methods of treatment of sleep bruxism.

Head posture and dental wear evaluation of bruxist children with primary teeth.

UNLABELLED: The aim of the present study was to compare the head position and dental wear of bruxist and non-bruxist children with primary dentition. METHODS: All the subjects had complete primary dentition, dental and skeletal class I occlusion and were classified as bruxist or non-bruxist according to their anxiety level, bruxism described by their parents and signs of temporomandibular disorders. The dental wear was drawn in dental casts and processed in digital format. Physiotherapeutic evaluation and a cephalometric radiograph with natural head position were also performed for each child to evaluate the cranio-cervical position for the bruxist group (n = 33) and the control group (n = 20). The variables of the two groups were compared, using the Student t-test and Mann-Whitney U-test. RESULTS: A more anterior and downward head tilt was found in the bruxist group, with statistically significant differences compared with the controls. More significant dental wear was observed in the bruxist children. CONCLUSIONS: Bruxism seems to be related to altered natural head posture and more intense dental wear. Further studies are necessary to explore bruxism mechanisms.

Condylar resorption during active orthodontic treatment and subsequent therapy: report of a special case dealing with iatrogenic TMD possibly related to orthodontic treatment.

A 28-year-old female underwent orthodontic treatment for approximately 22 months. During the later stages of this treatment, the patient reported right shoulder and neck-muscle pain. In addition, temporomandibular joint disorder (TMD) with a 'clicking' sound during mastication commenced 5 months prior to treatment completion. Specific medication to deal with these symptoms was suggested by medical specialists, as were some stress-relief methods, although the pain still progressed, and subsequent clinical and radiographical examinations were undertaken by another orthodontist. Right mandibular condylar resorption was observed from both the panorex and temporomandibular joint (TMJ) radiographs. No clinical signs of rheumatic disease were observed, although bruxism was noted. Following the termination of the orthodontic treatment by the second practitioner, the patient was treated with splint therapy 1 month subsequent to which, the previous symptoms of pain in the shoulder and neck, and the clicking sound during mastication had subsided. During the 14-month period of splint therapy and follow-up, new bone growth in the right condyle was observed from radiographs.

The effects of sustained incisal clenching on the temporomandibular joint space.

OBJECTIVE: To determine the effect of sustained incisal clenching on the width of the temporomandibular joint space. METHODS: Nine normal subjects clenched on an anterior appliance for 10 min at 49 N. Sagittal tomograms were obtained during comfortable closure in the intercuspal position (ICP) (ICP-Before), comfortable closure on bite force transducer without clenching (BFT-Before), start of clenching (BFT-0), end of 5 min clenching (BFT-5), end of 10 min clenching (BFT-10), comfortable closure on the bite force transducer immediately after clenching (BFT-After) and comfortable closure in ICP after clenching (ICP-After). Joint space dimensions were automatically measured by a computerized image analysis system. RESULTS: The minimum joint space dimension was significantly reduced at BFT-5 (P = 0.0381), BFT-10 (P = 0.0019) and BFT-After (P = 0.0053) in relation to BFT-Before. The condylar position was also significantly shifted upward at BFT-0 (P = 0.0422), BFT-5 (P = 0.0005), BFT-10 (P = 0.0001), and BFT-After (P = 0.0004) in relation to BFT-Before. CONCLUSION: Sustained incisal clenching at 49 N causes significant anterior joint space reduction. We believe this is due to marked compression of the articular cartilage and disc.

Effects of the D2 receptor agonist bromocriptine on sleep bruxism: report of two single-patient clinical trials.

An altered dopamine receptor status has been associated with sleep bruxism. Evidence from a functional neuro-imaging study has implicated an abnormal side imbalance in striatal D2 receptor expression in its pathophysiology. To assess the significance of this finding, we studied the effects of short-term administration of the preferential dopamine D2 receptor agonist bromocriptine on sleep bruxism in a double-blind, placebo-controlled polysomnographic and neuro-imaging study with a single crossover design. Six otherwise healthy and drug-free patients with sleep bruxism were entered into the trial. One of the patients dropped out due to an intercurrent illness, while three others were discontinued from the study due to severe adverse reactions to bromocriptine. Because of the high frequency and intensity of the side-effects, the trial was interrupted. Two patients, however, completed the trial without any adverse reactions. Their outcome measures are presented as single-patient clinical trials. Following a two-week administration of bromocriptine, both patients showed a decrease in the number of bruxism episodes per hour of sleep of about 20% to 30% with respect to the placebo. WHile no significant differences between both conditions (i.e., placebo and bromocriptine) were found for the number of bruxism bursts per episode, significantly lower root-mean-squared EMG levels per bruxism burst occurred during bromocriptine use. In association with this polysomnographically established attenuation of sleep bruxism, bromocriptine afforded a decreased normal side distribution of striatal D2 receptor binding, as was evidenced by single-photon-emission computed tomography using the radioactive D2 receptor antagonist iodine-123-iodobenzamide. This study supports previous suggestions that the central dopaminergic system may be involved in the modulation of sleep bruxism. To see if the present findings apply across a population, investigators should use a peripheral D-2 antagonist to prevent side-effects.

Striatal D2 receptor binding in sleep bruxism: a controlled study with iodine-123-iodobenzamide and single-photon-emission computed tomography.

The neurochemical mechanisms underlying sleep bruxism are little understood at present. However, recent pharmacologic evidence suggests that the central dopaminergic system may be involved in the pathophysiology of sleep bruxism. This possibility was further assessed by means of functional neuroimaging of dopamine D2 receptors with single-photon-emission computed tomography (SPECT). Ten controls and ten patients with polysomnographically confirmed sleep bruxism were injected intravenously with 185 MBq (5 mCi) iodine-123-iodobenzamide, a specific D2 receptor antagonist radioligand, and data acquisition was performed 90 min post-injection. Following image reconstruction, it was found that striatal D2 receptor binding potential (basal ganglia/background ratio) did not differ significantly between bruxism patients and controls. However, side-to-side differences between unilateral values of the striatal D2 binding potential ("highest side" values minus "lowest side" values) were significantly larger for the bruxism patients (p < 0.001, by two-independent-samples t test with pooled variances). It was concluded that an abnormal side imbalance in striatal D2 receptor expression can be associated with sleep bruxism. This reinforces the possibility that the central dopaminergic system plays a role in the pathophysiology of this disorder.

Periodontal status and bruxism. A comparative study of patients with periodontal disease and occlusal parafunctions.

This study investigated a possible association between bruxism and severity of periodontal disease. Subjects consisted of 51 patients (mean age 47.3 years) referred to the Department of Periodontology for treatment of moderate to severe periodontal disease (Perio-group) and 40 patients (mean age 48.9 years) referred to the Department of Stomatognathic Physiology for treatment of symptoms related to bruxism (Bruxism-group). Examination of the two groups included measurements of the alveolar bone height, probing attachment level, tooth mobility, and attrition of teeth. A questionnaire was also used to gain information on the patient's awareness of bruxism and tooth mobility. Awareness of clenching and/or grinding was reported by 57% of patients in the Bruxism-group and 24% of patients in the Perio-group. The perio-patients reported significantly higher frequency of tooth mobility than did the bruxism-patients. Alveolar bone loss, attachment loss, and tooth mobility were significantly more pronounced in the Perio-group than in the Bruxism-group. The Bruxism-group showed a higher frequency of tooth attrition than the Perio-group. Periodontal disease and bruxism seldom occurred in the same individual, and the results indicate that the two phenomena are in general not closely associated.