Influence of mandibular tori on stomatognathic system function

Intervertebral Disc Degeneration: Functional Analysis of Bite Force and Masseter and Temporal Muscles Thickness

Intervertebral disc degeneration is a pathological condition associated with the intervertebral disc and is related to functional alterations in the human body. This study aimed to evaluate the maximum molar bite force and masseter and temporal muscles thickness in individuals with intervertebral disc degeneration. Thirty-two individuals were divided into two groups: those with degeneration of intervertebral discs (n=16) and those without degeneration (n=16). The maximum molar bite force (on the right and left sides) was measured using a dynamometer. Masseter and temporal muscle thickness during mandibular task rest and dental clenching in maximum voluntary contraction were analysed using ultrasound. Significant differences in the left molar bite force (p=0.04) were observed between the groups (Student's t-test, p<0.05). The intervertebral disc degeneration group had a lower maximum molar bite force. No significant differences in muscle thickness were observed between the masseter and temporal muscles in either group. However, based on clinical observations, the group with intervertebral disc degeneration presented less masseter muscle thickness and greater temporal muscle thickness in both mandibular tasks. Degenerative disease of the intervertebral discs promoted morphofunctional changes in the stomatognathic system, especially in maximum molar bite force and masticatory muscle thickness. This study provides insight into the interaction between spinal pathology and the stomatognathic system, which is important for healthcare professionals who treat patients with functional degeneration.

Bite Force, Thickness, and Thermographic Patterns of Masticatory Muscles Post-Hemorrhagic Stroke

OBJECTIVE

Stroke is a neurological deficit of cerebrovascular origin, considered a 21st-century epidemic that causes functional changes in the human body. This study aimed to evaluate the stomatognathic system of patients after hemorrhagic stroke through the bite force, thickness, and skin temperature in the region of the masseter and temporalis muscles.

MATERIAL AND METHODS

Twenty-four subjects were divided into groups: post-hemorrhagic stroke; with right side of the affected body (n = 12) and without the neurological disorder (n = 12). Maximum molar bite force was verified using a digital dynamometer. Muscle thickness was measured using ultrasound images obtained at rest and during maximal voluntary contraction of the masseter and temporalis muscles. Thermographic camera was used to record the thermographic patterns of the masseter and temporalis muscles. Data were subjected to Student's t-test (P < .05).

RESULTS

The maximum molar bite force showed significant differences in the right (P = .04) and left (P = .03) sides, with a reduction in force in the post-hemorrhagic stroke group on the affected and unaffected sides. There was a significant difference (P < .05) in the thickness of the left temporal muscle at mandibular rest (P = .01) between groups. The post-hemorrhagic stroke group clinically presented greater muscle thickness in almost 100% of the muscles evaluated in both clinical conditions. There were no significant differences in skin temperature in the masseter and temporal muscles between the groups.

CONCLUSIONS

Our results suggest functional changes in the stomatognathic system of subjects after a hemorrhagic stroke, especially concerning molar bite force and masticatory muscle thickness in the temporal muscle (unaffected side).

Electromyographic analysis of stomatognathic muscles in elderly after hippotherapy

The aging process affects the entire human body, including the stomatognathic system, and can trigger not only occlusal but also postural imbalances involving other muscular chains. Hippotherapy has been used to promote cervical, postural, and balance control in individuals with diverse impairments. The present study used electromyography to evaluate the masseter and temporal muscles in an elderly population pre- and post-hippotherapy. Participants included 17 individuals, mean age 66,5±7 years. Electromyographic recording of the bilateral masseter and temporal muscles was performed during the postural resting condition and activities that involved the active participation of these muscles in different conditions. The practitioner performed no other type of activity or exercise during the intervention because the objective is to evaluate the effect of the three-dimensional movement provided by the horse. Raw electromyographic data were tabulated using commercially available software (IBM® SPSS® Statistics 234.0) and subjected to statistical analysis, in which p ≤ 0.05 was considered to be statistically significant. Post-hippotherapy, there was lower electromyographic activity for the masseter and temporalis muscles in all the static mandibular tasks, with significant effect for time for the right temporal muscle (p = 0.038), the left temporal muscle (p = 0.028) and in the all dynamic mandibular tasks for the left temporal muscle (p = 0.025) and the left masseter muscle (p = 0.027). Hippotherapy promotes a reduction in the myoelectric activity of the masticatory muscles of elderly individuals.

Osteoarthrosis: Analyze of the Molar Bite Force, Thickness and Masticatory Efficiency

Osteoarthrosis is a disorder of synovial joints, resulting from destruction of the cartilage and subchondral bone. The present study is aimed to investigate the molar bite force, thickness and efficiency of the masseter and temporalis muscles of subjects with osteoarthrosis. A total of forty-eight subjects participated in the study. They were distributed into two groups: with osteoarthrosis (n=24) and asymptomatic controls (n=24). Subjects were analyzed on the basis of maximal molar bite force (right and left side), thickness (mandibular rest and dental clenching in maximal voluntary contraction) and electromyographic activity of masticatory cycles through the linear envelope integral in habitual (raisins and peanuts) and non-habitual (Parafilm M) chewing of the masseter and temporalis muscles. All the data were analyzed statistically using t-test with a significance level of p≤0.05. There was no difference between groups in maximal molar bite force, muscle thickness and non-habitual chewing. Differences were found on the raisins (p=0.02) and peanuts (p=0.05) chewing for right temporal muscle, with reduced masticatory muscle efficiency in osteoarthrosis subjects. This study showed that osteoarthrosis induces negative changes in habitual chewing, highlighting the efficiency of the right temporalis muscles. The greater temporal muscle activity in subjects with osteoarthrosis may compromise chewing and consequently the nutritional status of adult subjects.

Impact of chronic allergic rhinitis on bite force and electromyographic activity of masseter and temporalis muscles of adult women

Background

The aim of this study was to analyse the stomatognathic system of adult women with chronic allergic rhinitis by means of molar bite force and electromyographic activity of the masseter and temporalis muscles.

Material and Methods

A total of 26 subjects were screened and divided into two distinct groups: chronic allergic rhinitis group (n = 13) and healthy control group (n = 13). Subjects were assessed by maximal molar bite force (right and left) and normalized electromyographic activity of mandibular tasks (rest, right and left laterality, protrusion and maximal voluntary contraction). Data were submitted to Student’s t test (p< .05).

Results

There was significant difference in right (p = .03) and left (p = .04) maximal molar bite force with force reduction in the chronic allergic rhinitis group. There was significant difference in normalized electromyographic activity in maximal voluntary contraction in the right (p =.01) and left (p = .01) temporalis muscles, with increased electromyographic activity in the masticatory muscles for the chronic allergic rhinitis group.

Conclusions

The results suggest that chronic allergic rhinitis in adult women promoted negative changes in the electromyographic activity of temporalis muscles in maximal voluntary contraction and maximal molar bite force.

Key words:Rhinitis, occlusal force, electromyography, masticatory muscles.

Spinocerebellar ataxia: Functional analysis of the stomatognathic system

BACKGROUND

Neurodegenerative diseases that affect the cerebellum, especially in elderly individuals, cause impairment of motor coordination and quality of life. The presente study evaluated the electromyographic activity and thickness of the right and left masseter and temporal muscles, and the maximum molar bite force of individuals with spinocerebellar ataxia.

MATERIAL AND METHODS

Twenty-eight individuals were divided into two groups: those with (n=14) and without (n=14) spinocerebellar ataxia. Data on the masticatory muscles obtained from the electromyographic activity (resting, right and left laterality and protrusion), muscle thickness (maximal voluntary contraction and tensile strength) and maximum bite force (right and left) were tabulated and descriptive analysis using Student's t-test (P ≤ 0.05).

RESULTS

In the comparison between groups, greater electromyographic activity was demonstrated for individuals with spinocerebellar ataxia, with a statistically significant difference in protrusion and laterality for the temporal muscles (P = 0.05). There was no statistically significant difference between the groups for masticatory muscles thickness in the conditions evaluated. For maximum molar bite force, the group with spinocerebellar ataxia showed lower bite force (P ≤ 0.05).

CONCLUSIONS

The data obtained suggest that spinocerebellar ataxia promotes functional reduction in the stomatognathic system, mainly affecting the electromyographic activity and bite force, hindering chewing, with a resultant alteration of nutritional intake and a decrease of quality of life.

Mandibular Torus Harvesting for Sinus Augmentation: Two-Year Follow-Up

Maxillary sinus grafting is a commonly used treatment alternative in cases with insufficient bone height to enable insertion of implants in the posterior maxilla. It is commonly carried out with autogenous grafts, biomaterials or both. Autogenous bone grafts are considered gold standard for this procedure; however, due to donor site morbidity, it is not as commonly used as other biomaterials. Mandibular tori are hyperostoses on the lingual side of the mandible in the premolar region. This a case in which mandibular tori were used for a sinus augmentation procedure. The patient was then followed up for 2 years with no complaints, or objective symptoms.

Analysis of the stomatognathic system of children according orthodontic treatment needs

PURPOSE

The present study evaluated electromyographic activity (EMG), masticatory performance, and tongue strength in children without and with orthodontic treatment needs.

PATIENTS AND METHODS

A total of 90 children were screened and divided into the following groups: Group I (no treatment needed; mean age: 8.00 ± 0.43 years; n = 26), Group II (few malocclusions, treatment needed; mean age: 8.89 ± 0.43 years; n = 28), and Group III (slight-to-borderline treatment needed; mean age: 8.44 ± 0.22 years; n = 36). Orthodontic treatment need was classified on the basis of IOTN-DHC (Index of Orthodontic Treatment Need - Dental Health Component). The electromyographic Trigno EMG Systems was used for muscle analysis and the Iowa Oral Pressure Instrument (IOPI) was used to measure tongue strength. Data were analyzed using normality tests and one-way analysis of variance with a Bonferroni post hoc test (p ≤ 0.05).

RESULTS

EMG in almost all mandibular movements was higher in Group III with statistically significant differences compared to position at rest: right masseter (p = 0.03); protrusion: left temporal (p = 0.02); saliva swallowing: left temporal (p = 0.05) and water swallowing: orbicularis oris mouth, right upper segment (p = 0.05). Lower masticatory performance was found in Group III, but the difference compared to Group I and II was not significant. There were no significant differences between the groups in terms of tongue strength.

CONCLUSIONS

Children with borderline orthodontic treatment needs show functional disorders of the stomatognathic system.

The relationship between oral tori and bite force

OBJECTIVE

The relationship between bite force and torus palatinus or mandibularis remains to be explained. The major aim of this study was to determine the correlation between bite force and oral tori.

METHODS

The bite force of 345 patients was measured with a bite force recorder; impressions of the shape and size of the oral tori were taken on plaster models prior to orthodontic treatments. Subsequently, the relationship between oral tori and bite force was analyzed.

RESULTS

The size, shape, and incidence of torus palatinus was not significantly correlated with bite force. However, the size of torus mandibularis increased significantly in proportion to the bite force (p = 0.020). The occurrence of different types of oral tori was not correlated with the bite force.

DISCUSSION

The size of torus mandibularis provides information about bite force and can thus be used to clinically assess occlusal stress.

Impact of temporomandibular disorders on the stomatognathic system in children

BACKGROUND

To evaluate the EMG activity and thickness of right masseter (RM), left masseter (LM), right temporal (RT) and left temporal (LT) muscles and bite force in children with temporomandibular disorders (TMD).

MATERIAL AND METHODS

Forty five children (mean age 8.8 years; 22 boys and 23 girls) were examined on the basis of the RDC/TMD and the Faces Pain Scale-Revised (FPS-R) was used to determine the level of severity of the signs and symptoms of TMD, resulting in four groups: GI - without TMD (n=10); GII - with mild TMD (n=18), GIII: with moderate TMD (n=12) and GIV: with severe TMD (n=5). The data of electromyographic activity, maximum bite force and muscle thickness were tabulated and submitted to statistical analysis (ANOVA, P≤0.05).

RESULTS

Children with TMD signs and symptoms had lower EMG activity than children of the control group. There was significant difference among the groups for the LT at rest (P=0.01), right (P=0.03) and left (P=0.05) laterality, and for the LM (P=0.01) and LT (P=0.03) muscles in maximum voluntary contraction. There were no statistically significant differences among the groups regarding muscle thickness. The bite force was lower in the TMD groups than children of the control group, with significant statistical difference for the right region (P=0.03).

CONCLUSIONS

The severity of TMD signs and symptoms affected the EMG activity and the molar bite force in children. However, structural changes in the thickness of masticatory muscles are not perceptible in children with TMD signs and symptoms.