Impaired Mastication Research Articles

Mastication movements and sleep quality of patients with myofascial pain: Occlusal device therapy improvements

Patients with myofascial pain experience impaired mastication, which might also interfere with their sleep quality. The purpose of this study was to evaluate the jaw motion and sleep quality of patients with myofascial pain and the impact of a stabilization device therapy on both parameters. Fifty women diagnosed with myofascial pain by the Research Diagnostic Criteria were enrolled. Pain levels (visual analog scale), jaw movements (kinesiography), and sleep quality (Epworth Sleepiness Scale; Pittsburgh Sleep Quality Index) were evaluated before (control) and after stabilization device use. Range of motion (maximum opening, right and left excursions, and protrusion) and masticatory movements during Optosil mastication (opening, closing, and total cycle time; opening and closing angles; and maximum velocity) also were evaluated. Repeated-measures analysis of variance in a generalized linear mixed models procedure was used for statistical analysis (α=.05). At baseline, participants with myofascial pain showed a reduced range of jaw motion and poorer sleep quality. Treatment with a stabilization device reduced pain (P<.001) and increased both mouth opening (P<.001) and anteroposterior movement (P=.01). Also, after treatment, the maximum opening (P<.001) and closing (P=.04) velocities during mastication increased, and improvements in sleep scores for the Pittsburgh Sleep Quality Index (P<.001) and Epworth Sleepiness Scale (P=.04) were found. Myofascial pain impairs jaw motion and quality of sleep; the reduction of pain after the use of a stabilization device improves the range of motion and sleep parameters.

Impaired mastication reduced newly generated neurons at the accessory olfactory bulb and pheromonal responses in mice

ObjectivesA large number of neurons are generated at the subventricular zone (SVZ) even during adulthood. In a previous study, we have shown that a reduced mastication impairs both neurogenesis in the SVZ and olfactory functions. Pheromonal signals, which are received by the vomeronasal organ, provide information about reproductive and social states. Vomeronasal sensory neurons project to the accessory olfactory bulb (AOB) located on the dorso-caudal surface of the main olfactory bulb. Newly generated neurons at the SVZ migrate to the AOB and differentiate into granule cells and periglomerular cells. This study aimed to explore the effects of changes in mastication on newly generated neurons and pheromonal responses. DesignBromodeoxyuridine-immunoreactive (BrdU-ir; a marker of DNA synthesis) and Fos-ir (a marker of neurons excited) structures in sagittal sections of the AOB after exposure to urinary odours were compared between the mice fed soft and hard diets. ResultsThe density of BrdU-ir cells in the AOB in the soft-diet-fed mice after 1 month was essentially similar to that of the hard-diet-fed mice, while that was lower in the soft-diet-fed mice for 3 or 6 months than in the hard-diet-fed mice. The density of Fos-ir cells in the soft-diet-fed mice after 2 months was essentially similar to that in the hard-diet-fed mice, while that was lower in the soft-diet-fed mice for 4 months than in the hard-diet-fed mice. ConclusionsThe present results suggest that impaired mastication reduces newly generated neurons at the AOB, which in turn impairs olfactory function at the AOB.

Pituitary abscess syndrome in a Simmental heifer

The clinical and pathological findings in a 1.7-year-old Simmental heifer with pituitary abscess syndrome due to sphenoid osteomyelitis, presumably resulting from a frontal sinusitis that developed subsequently to dehorning, are...

Current nanotechnological strategies for an effective delivery of drugs in treatment of periodontal disease.

Periodontal disease is a localized inflammatory disorder, with tissue destruction resulting from the host response to bacterial antigens and irritants. Several other risk factors, such as smoking, hormonal changes, diabetes, drugs, disease, and genetic factors, play an important role in the progression of periodontal disease. This disease results in the formation of periodontal pockets or deepened crevices between the gingival and tooth root that produce occasional pain and discomfort, impaired mastication, and irreversible tooth loss. The primary rationale for controlled, sustained, and targeted drug delivery is necessary to achieve better therapeutic outcomes or patient compliance against periodontal disease and its various stages. Both systemic (liposomes, microspheres, nanoparticles, hydrogels) and local (fibers, patches, films, gels) antibiotic/antimicrobial approaches have their important place in periodontal therapy. The overall goal of this article is to provide the clinician with information related to the pathogenesis, risk, polymer used for drug delivery, and current nanotechnological systems for an effective treatment of periodontal disease.

Novel diet for patients with impaired mastication evaluated by consumption rate, nutrition intake, and questionnaire

Objective“iEat®” (EN Otsuka Pharmaceutical Co. Ltd.; study diet), a food product that resembles an ordinary meal in appearance but is cooked to soften, was compared with foods provided to patients with impaired mastication (modified traditional diet) to investigate the influence of the appearance of foods on the consumption rate, dietary nutrition intake, and satisfaction level. MethodsAfter serving the study participants the modified traditional diet on days 1 and 2, the study diet on days 3, 4, and 5, and the modified traditional diet on days 6 and 7, the consumption rates were measured by weight difference. The amounts of dietary nutrition intake were calculated from the consumption rates. Satisfaction levels were evaluated by a questionnaire completed by the participants and their health care professionals after each meal. ResultsNo significant difference in consumption rates was observed between the study diet and the modified traditional diet. The amounts of dietary nutrition intake of energy and protein were significantly higher for the study diet than for the modified traditional diet. The study diet showed higher satisfaction levels in terms of “appearance” when evaluated by the participants, and “joy of eating” and “overall satisfaction level” when evaluated by the health care professionals. ConclusionThe study diet has potential to become a new dietary option for patients with impaired mastication.

Lymphatic Malformations in Children and Adolescents

This article aimed to present a series of surgically treated lymphatic malformations of the cervicofacial region in a population of children and adolescents during a 13-year period. The medical records of all children and adolescents with cervicofacial lymphatic malformations, treated surgically at our department from 1998 to 2011, were reviewed retrospectively. Eighteen patients with 20 lymphatic malformations located within the soft tissues of the cervicofacial region were identified. All patients were submitted to surgical treatment (excision or resection with conventional scalpel or radiosurgery) to address complications (ulceration, bleeding, impaired mastication and feeding, airway obstruction) and/or aesthetic issues. Recurrence was noted in 2 of our patients. Accurate diagnosis based on history, clinical examination, and adequate imaging techniques is the key to the optimal treatment of cervicofacial lymphatic malformations; surgical intervention remains the treatment of choice for these lesions.

Mastication Dyspraxia: A Neurodevelopmental Disorder Reflecting Disruption of the Cerebellocerebral Network Involved in Planned Actions

This paper reports the longitudinal clinical, neurocognitive, and neuroradiological findings in an adolescent patient with nonprogressive motor and cognitive disturbances consistent with a diagnosis of developmental coordination disorder (DCD). In addition to prototypical DCD, the development of mastication was severely impaired, while no evidence of swallowing apraxia, dysphagia, sensorimotor disturbances, abnormal tone, or impaired general cognition was found. He suffered from bronchopulmonary dysplasia and was ventilated as a newborn for 1.5 months. At the age of 3 months, a ventriculoperitoneal shunt was surgically installed because of obstructive hydrocephalus secondary to perinatal intraventricular bleeding. At the age of 5 years, the patient's attempts to masticate were characterized by rough, effortful, and laborious biting movements confined to the vertical plane. Solid food particles had a tendency to get struck in his mouth and there was constant spillage. As a substitute for mastication, he moved the unground food with his fingers in a lateral direction to the mandibular and maxillary vestibule to externally manipulate and squeeze the food between cheek and teeth with the palm of his hand. Once the food was sufficiently soft, the bolus was correctly transported by the tongue in posterior direction and normal deglutition took place. Repeat magnetic resonance imaging (MRI) during follow-up disclosed mild structural abnormalities as the sequelae of the perinatal intraventricular bleeding, but this could not explain impaired mastication behavior. Quantified Tc-99m-ethylcysteinate dimer single-photon emission computed tomography (Tc-99m-ECD SPECT), however, revealed decreased perfusion in the left cerebellar hemisphere, as well as in both inferior lateral frontal regions, both motor cortices, and the right anterior and lateral temporal areas. Anatomoclinical findings in this patient with DCD not only indicate that the functional integrity of the cerebellocerebral network is crucially important in the planning and execution of skilled actions, but also seem to show for the first time that mastication deficits may be of true apraxic origin. As a result, it is hypothesized that "mastication dyspraxia" may have to be considered as a distinct nosological entity within the group of the developmental dyspraxias following a disruption of the cerebellocerebral network involved in planned actions.

Surgical management of head and neck vascular anomalies in children: a retrospective analysis of 42 patients

This article aimed to present a series of surgically treated head and neck vascular anomalies during a 12-year period, highlighting the epidemiology, diagnostic approach, indications for surgery, and final clinical outcome. The medical records of all patients with head and neck vascular anomalies, surgically treated at our department from 1998 to 2010, were reviewed retrospectively. A total of 42 patients with 46 vascular anomalies were identified. Patients' diagnoses included vascular tumors, hemangiomas mainly (18 cases), and various vascular malformations (26 cases). All patients were submitted to surgical treatment (excision-resection) to resolve main clinical symptoms (ulceration, bleeding, impaired mastication and feeding, airway obstruction) and/or esthetic issues. Recurrence was noted in 3 patients. Accurate differential diagnosis based on history, physical examination, and imaging, is the key to optimal treatment. Surgical intervention is warranted for small to moderately extended lesions to avoid complications and/or esthetic concerns and psychosocial distress.

An experimental model of focal ischemia using an internal carotid artery approach

Animal models of cerebral ischemia represent an important contribution to both our understanding of stroke mechanism and the development of new therapies. The technique of MCAO (middle cerebral artery occlusion) via ECA (external carotid artery) occlusion is widely utilized. Disruption of the ECA and its branches leads to impaired mastication and oral intake, post-surgical body weight loss, and poor neurological recovery which can possibly confound one's interpretation of rats’ neurological outcome. Here, we developed a novel modified technique for MCAO without ligation or coagulation of the ECA and its branches using an approach via the internal carotid artery (ICA). In our modified technique, we perform an additional fixation of the filament in the ICA which improves the stability of the model and increases the homogeneity in stroke size. Compared with the original MCAO technique via the ECA, our modified technique via the ICA demonstrated decreased variability in the percent infarcted volume and brain edema, as well as a decreased mortality. Additionally, we observed that with our modified technique, rats gained more weight after surgery and there was less initial weight loss after the surgical preparation. Our new approach may serve as an effective model for stroke, and may lead to a better understanding of stoke pathophysiology and to the future development of new drugs and other neuroprotective agents.

The regulation of masticatory function and food bolus formation

This review emphasizes the following points: 1. The values of the physiological parameters of mastication (number of cycles and total electromyographic activity in the sequence, sequence duration, cycle frequency in the sequence, kinetic characteristics of the cycles) are characteristic of each individual and vary widely from one individual to another. In a given individual their modification reflects an adaptation of mastication to the size of the food bolus, and the hardness and rheological characteristics of the food. 2. The ready-to-swallow food boluses produced by different individuals nevertheless display similar particle size distributions. 3. Ageing entails adaptation of the masticatory function and does not impair swallowing. 4. Observed increase in total electromyographic activity shows that more energy is expended in mastication by full denture wearers. Despite this increased muscle activity, loss of teeth, even if compensated for by complete dentures, hinders the formation of a normal bolus. The food boluses made by denture wearers thus contain many large-size particles. The impaired mastication observed in denture wearers approaches the masticatory disabilities found in persons with neuromotor deficiencies.

Response: Determinants of Body Weight Changes in the MCAO Filament Model

Response: Determinants of Body Weight Changes in the MCAO Filament Model

External carotid artery territory ischemia impairs outcome in the endovascular filament model of middle cerebral artery occlusion in rats.

Middle cerebral artery occlusion (MCAO) by an intraluminal filament is a widely accepted animal model of focal cerebral ischemia. In this procedure, cutting of the external carotid artery (ECA) is a prerequisite for thread insertion. However, the implications of ECA transsection have not yet been described. After 90 minutes of filament MCAO or sham surgery, rats were evaluated for up to 14 days in terms of body weight development, core temperature, and motor performance. Repeated in vivo MRI of the head and neck was performed for quantification of brain edema and infarct volume. The temporal muscles were histologically analyzed postmortem. In 47% of all rats, ischemic tissue damage to the ipsilateral ECA area, including temporal, lingual, and pharyngeal musculature, was detectable by MRI. Histology of temporal muscles confirmed acute ischemic myopathy. Animals with ECA territory ischemia (ECA-I) showed delayed body weight development and poorer recovery of motor function. There was no difference in the extent of brain edema or final cerebral lesion size between ECA-I-affected and unaffected rats. Filament MCAO was complicated by the consequences of ECA ischemia in approximately half of all rats. Impaired mastication and swallowing functions restricted ingestion and resulted in postsurgical body weight loss and worse motor performance. Impaired cerebral microperfusion resulting from dehydration and reduced spontaneous motor activity resulting from reduced food and water uptake might have contributed to poorer neurological recovery in ECA ischemic rats. Thus, adverse effects caused by extracerebral ischemia with potential impact on outcome have to be considered in this stroke model.

Radial forearm free flap for soft palate reconstruction.

Defects of the soft palate resulting from head and neck oncologic surgery traditionally have been rehabilitated using a prosthetic obturator. In general, the results of soft palate obturation have been satisfactory, with most patients achieving velopharyngeal competence during speech and swallowing. However, soft palate obturators have several disadvantages. Device stability and retention are impaired in patients who are edentulous. In addition, prosthetic obturators cover large areas of sensate mucosa in the hard palate, maxillary alveolus, and oropharynx, contributing significantly to the loss of sensory feedback from the oral cavity and oropharynx. Considerable evidence suggests that sensory impairment within the oral cavity and pharynx results in impaired mastication, deglutition, and articulation. A minority of patients find palatal obturators to be unsatisfactory, secondary to either inconvenience or device discomfort.

Prepharyngeal dysphagia in Parkinson's disease

Dysphagia in patients with Parkinson's disease (PD) is most often attributed to pharyngeoesophageal motor abnormalities. In our study of patients with idiopathic PD, attention was focused on prepharyngeal symptoms and motor functions. Using the Hoehn and Yahr disease severity scale, patients were grouped into those with mild/moderate disease [subgroup I (n = 38)] and those with advanced disease [subgroup II (n = 34)]. Dysphagia symptoms were present in 82% of all patients, but subgroup I patients voiced significantly more complaints. Conversely, many prepharyngeal abnormalities of ingestion, including jaw rigidity, impaired head and neck posture during meals, upper extremity dysmotility, impulsive feeding behavior, impaired amount regulation, and lingual transfer movements were statistically more frequent in subgroup II patients. Impaired mastication and oral preparatory lingual movements were the most common aberrations observed during dynamic videofluoroscopy (48/71), with most patients being concordant for both. The motor disturbances of ingestion reported herein reflect the disintegration of volitional and automatic movements caused by PD-related akinesia, bradykinesia, and rigidity.

Induction of an olfactory memory by the activation of a metabotropic glutamate receptor in the accessory olfactory bulb

A large number of neurons are generated at the subventricular zone (SVZ) even during adulthood. In a previous study, we have shown that a reduced mastication impairs both neurogenesis in the SVZ and olfactory functions. Pheromonal signals, which are received by the vomeronasal organ, provide information about reproductive and social states. Vomeronasal sensory neurons project to the accessory olfactory bulb (AOB) located on the dorso-caudal surface of the main olfactory bulb. Newly generated neurons at the SVZ migrate to the AOB and differentiate into granule cells and periglomerular cells. This study aimed to explore the effects of changes in mastication on newly generated neurons and pheromonal responses.Bromodeoxyuridine-immunoreactive (BrdU-ir; a marker of DNA synthesis) and Fos-ir (a marker of neurons excited) structures in sagittal sections of the AOB after exposure to urinary odours were compared between the mice fed soft and hard diets.The density of BrdU-ir cells in the AOB in the soft-diet-fed mice after 1 month was essentially similar to that of the hard-diet-fed mice, while that was lower in the soft-diet-fed mice for 3 or 6 months than in the hard-diet-fed mice. The density of Fos-ir cells in the soft-diet-fed mice after 2 months was essentially similar to that in the hard-diet-fed mice, while that was lower in the soft-diet-fed mice for 4 months than in the hard-diet-fed mice.The present results suggest that impaired mastication reduces newly generated neurons at the AOB, which in turn impairs olfactory function at the AOB.

Tooth loss, mastication, and nutrition: An overview

Objective: To evaluate the maximum bite force (MBF), masticatory performance and oral sensory function (OSF) of frail edentulous elderly. The correlation of MBF with maximum grip strength (MGS) was also assessed. Methods: Twenty edentulous elderly [10 with and 10 without the frailty phenotype (FP)] were selected to participate in this case–control study. The FP was diagnosed using the criteria of Fried et al., which consider weight loss, exhaustion, physical activity level, weakness and slowness to the evaluation. All volunteers received new complete dentures (CDs) to standardise the occlusal status, and after 2 months of use with no complaint, all variables were assessed. MBF was measured by pressure sensors positioned bilaterally on the first artificial molars. Masticatory performance was assessed using the sieving method and was expressed as the median particle size (X50) of Optocal after 40 masticatory cycles. OSF was evaluated using the oral stereognosis test, and MGS was measured using a dynamometer. Groups were compared using one-way analysis of variance. The Pearson coefficient of correlation between MBF and MGS was calculated. Results: Frail elderly people showed reduced MBF (P = 0.0431) and larger X50 values (P = 0.0053) than did non-frail elders, while OSF did not differ between the groups. MBF had a moderate positive correlation with MGS (r = 0.690, P = 0.003). Conclusions: Frail elderly had reduced MBF and impaired mastication. On the other hand, OSF does not seem to be affected by frailty. MBF was moderately correlated with MGS.

Management of patients with myasthenia gravis who require maxillary dentures

Some signs of myasthenia gravis can be clearly identified in the oral cavity. The patient with progressive neuromuscular impairment may seek consultation because of dysphagia, impaired mastication, and dysarthria. The dentist should understand the pathophysiology of the symptoms and treat the myasthenic patient accordingly.

Effect of impaired mastication on the health of rats.

Long-term ingestion of insufficiently masticated food, which resulted from extraction of posterior teeth, was especially detrimental to the health of old male rats. Although gastrointestinal pathology was not seen in most instances, the three rats that showed stomach ulcerations were the rats that had ingested the highest percentages of coarse particles.

Bezoar following gastrectomy.

An intragastric grape phytobezoar occurred 1 month after hemigastrectomy, duodenostomy, and vagotomy. Bezoar formation was believed due to a combination of reduced proteolytic enzyme activity, faulty mixing, gastric stasis, and impaired mastication. Medical therapy with oral proteolytic enzymes and gastric lavage resulted in the complete disappearance of the bezoar, as demonstrated both roentgenographically and gastroscopically.

Changes in the mandibular condyles of mice following the use of orthodontic bite plates

It has been demonstrated in several ways that the form of the developing mandibular condyle of the mouse is influenced not so much by the mechanical effect of a bite plate as by malnutrition resulting from impaired mastication.