Mastication: The act and process of chewing and grinding food in the mouth.Masticatory Muscles: Muscles arising in the zygomatic arch that close the jaw. Their nerve supply is masseteric from the mandibular division of the trigeminal nerve. (From Stedman, 25th ed)Bite Force: The force applied by the masticatory muscles in dental occlusion.Stomatognathic System: The mouth, teeth, jaws, pharynx, and related structures as they relate to mastication, deglutition, and speech.Masseter Muscle: A masticatory muscle whose action is closing the jaws.Temporal Muscle: A masticatory muscle whose action is closing the jaws; its posterior portion retracts the mandible.Jaw: Bony structure of the mouth that holds the teeth. It consists of the MANDIBLE and the MAXILLA.Mandible: The largest and strongest bone of the FACE constituting the lower jaw. It supports the lower teeth.Deglutition: The act of taking solids and liquids into the GASTROINTESTINAL TRACT through the mouth and throat.Trigeminal Nuclei: Nuclei of the trigeminal nerve situated in the brain stem. They include the nucleus of the spinal trigeminal tract (TRIGEMINAL NUCLEUS, SPINAL), the principal sensory nucleus, the mesencephalic nucleus, and the motor nucleus.Jaw Relation Record: A registration of any positional relationship of the mandible in reference to the maxillae. These records may be any of the many vertical, horizontal, or orientation relations. (Jablonski, Illustrated Dictionary of Dentistry)Nasal Cartilages: Hyaline cartilages in the nose. There are five major nasal cartilages including two lateral, two alar, and one septal.Swine, Miniature: Genetically developed small pigs for use in biomedical research. There are several strains - Yucatan miniature, Sinclair miniature, and Minnesota miniature.Jaw Fixation Techniques: The stable placement of surgically induced fractures of the mandible or maxilla through the use of elastics, wire ligatures, arch bars, or other splints. It is used often in the cosmetic surgery of retrognathism and prognathism. (From Dorland, 28th ed, p636)Zygoma: Either of a pair of bones that form the prominent part of the CHEEK and contribute to the ORBIT on each side of the SKULL.Hardness: The mechanical property of material that determines its resistance to force. HARDNESS TESTS measure this property.Facial Muscles: Muscles of facial expression or mimetic muscles that include the numerous muscles supplied by the facial nerve that are attached to and move the skin of the face. (From Stedman, 25th ed)Mechanical Phenomena: The properties and processes of materials that affect their behavior under force.Temporomandibular Joint: An articulation between the condyle of the mandible and the articular tubercle of the temporal bone.Skull: The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.Sucking Behavior: Any suction exerted by the mouth; response of the mammalian infant to draw milk from the breast. Includes sucking on inanimate objects. Not to be used for thumb sucking, which is indexed under fingersucking.Cranial Sutures: A type of fibrous joint between bones of the head.Tongue: A muscular organ in the mouth that is covered with pink tissue called mucosa, tiny bumps called papillae, and thousands of taste buds. The tongue is anchored to the mouth and is vital for chewing, swallowing, and for speech.Mandibular Condyle: The posterior process on the ramus of the mandible composed of two parts: a superior part, the articular portion, and an inferior part, the condylar neck.Food: Any substances taken in by the body that provide nourishment.Denture, Complete, Lower: A complete denture replacing all the natural mandibular teeth and associated structures. It is completely supported by the oral tissue and underlying mandibular bone.Feeding Behavior: Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.Temporomandibular Joint Disorders: A variety of conditions affecting the anatomic and functional characteristics of the temporomandibular joint. Factors contributing to the complexity of temporomandibular diseases are its relation to dentition and mastication and the symptomatic effects in other areas which account for referred pain to the joint and the difficulties in applying traditional diagnostic procedures to temporomandibular joint pathology where tissue is rarely obtained and x-rays are often inadequate or nonspecific. Common diseases are developmental abnormalities, trauma, subluxation, luxation, arthritis, and neoplasia. (From Thoma's Oral Pathology, 6th ed, pp577-600)Habits: Acquired or learned responses which are regularly manifested.Dental Abutments: Natural teeth or teeth roots used as anchorage for a fixed or removable denture or other prosthesis (such as an implant) serving the same purpose.Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.Poaceae: A large family of narrow-leaved herbaceous grasses of the order Cyperales, subclass Commelinidae, class Liliopsida (monocotyledons). Food grains (EDIBLE GRAIN) come from members of this family. RHINITIS, ALLERGIC, SEASONAL can be induced by POLLEN of many of the grasses.Nasal Septum: The partition separating the two NASAL CAVITIES in the midplane. It is formed by the SEPTAL NASAL CARTILAGE, parts of skull bones (ETHMOID BONE; VOMER), and membranous parts.Dental Occlusion: The relationship of all the components of the masticatory system in normal function. It has special reference to the position and contact of the maxillary and mandibular teeth for the highest efficiency during the excursive movements of the jaw that are essential for mastication. (From Jablonski, Dictionary of Dentistry, 1992, p556, p472)Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Deglutition Disorders: Difficulty in SWALLOWING which may result from neuromuscular disorder or mechanical obstruction. Dysphagia is classified into two distinct types: oropharyngeal dysphagia due to malfunction of the PHARYNX and UPPER ESOPHAGEAL SPHINCTER; and esophageal dysphagia due to malfunction of the ESOPHAGUS.Video Recording: The storing or preserving of video signals for television to be played back later via a transmitter or receiver. Recordings may be made on magnetic tape or discs (VIDEODISC RECORDING).Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Tooth: One of a set of bone-like structures in the mouth used for biting and chewing.Animal Feed: Foodstuff used especially for domestic and laboratory animals, or livestock.Digestion: The process of breakdown of food for metabolism and use by the body.Infant Behavior: Any observable response or action of a neonate or infant up through the age of 23 months.Dictionaries, MedicalDictionaries as Topic: Lists of words, usually in alphabetical order, giving information about form, pronunciation, etymology, grammar, and meaning.Bites and StingsDaucus carota: A plant species of the family APIACEAE that is widely cultivated for the edible yellow-orange root. The plant has finely divided leaves and flat clusters of small white flowers.Centric Relation: The location of the maxillary and the mandibular condyles when they are in their most posterior and superior positions in their fossae of the temporomandibular joint.Vibration: A continuing periodic change in displacement with respect to a fixed reference. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Facial Pain: Pain in the facial region including orofacial pain and craniofacial pain. Associated conditions include local inflammatory and neoplastic disorders and neuralgic syndromes involving the trigeminal, facial, and glossopharyngeal nerves. Conditions which feature recurrent or persistent facial pain as the primary manifestation of disease are referred to as FACIAL PAIN SYNDROMES.Temporomandibular Joint Disc: A plate of fibrous tissue that divides the temporomandibular joint into an upper and lower cavity. The disc is attached to the articular capsule and moves forward with the condyle in free opening and protrusion. (Boucher's Clinical Dental Terminology, 4th ed, p92)Betula: A plant genus of the family BETULACEAE. The tree has smooth, resinous, varicolored or white bark, marked by horizontal pores (lenticels), which usually peels horizontally in thin sheets.Vinyl Chloride: A gas that has been used as an aerosol propellant and is the starting material for polyvinyl resins. Toxicity studies have shown various adverse effects, particularly the occurrence of liver neoplasms.

Midpalatal suture of osteopetrotic (op/op) mice exhibits immature fusion. (1/522)

The midpalatal suture was observed histologically in both toothless osteopetrotic (op/op) and normal (control) mice. The normal mice had a mature sutural structure, which consists of a well-developed cartilage cell zone and palatal bone. In contrast, the thickness of the cartilage cell zone was substantially greater in the op/op mice than that in the controls. Moreover, the cartilage cells in the op/op mice were frequently found in the palatal bone as well as in the sutural space, exhibiting an imperfect fusion. It seems that immature fusion at the sutural interface in the op/op mice is related to a decrease in biting or masticatory force accompanied by the failure of tooth eruption in addition to an essential defect in osteoclast differentiation, which is a congenital symptom in op/op mice.  (+info)

Motivation for and satisfaction with orthodontic-surgical treatment: a retrospective study of 28 patients. (2/522)

Motivation for starting treatment and satisfaction with treatment results were evaluated on the basis of replies to a 14-item questionnaire and clinical examination of 28 orthognathic patients from 6 months to 2 years after treatment. The most common reasons for seeking professional help were problems in biting and chewing (68 per cent). Another major reason was dissatisfaction with facial appearance (36 per cent). Many patients also complained of temporomandibular joint symptoms (32 per cent) and headache (32 per cent). Women (8/19) were more often dissatisfied with their facial appearance than men (2/9), but the difference was not statistically significant. In agreement with earlier studies, the results of orthognathic treatment fulfilled the expectations of almost every patient. Nearly 100 per cent of the patients (27/28) were satisfied with treatment results, although 40 per cent experienced some degree of numbness in the lips and/or jaw 1 year post-operatively. The most satisfied patients were those who stated temporomandibular disorders as the main reason for seeking treatment and whose PAR-index had improved greatly. The majority of the patients experienced the orthodontic treatment as painful and as the most unpleasant part of the whole treatment, but all the patients were satisfied with the pre-treatment information they were given on orthodontics. Orthodontic-surgical therapy should be of a high professional standard technically, but the psychological aspects are equally important in the treatment protocol. The professionals should make efforts to understand the patient's motivations for and expectations of treatment. Patients should be well prepared for surgery and supported for a long time after to help them to adjust to post-surgical changes.  (+info)

Mastication steal: an unusual precipitant of cerebrovascular insufficiency. (3/522)

An 83-year-old man had episodic dizziness, visual disturbance, and facial and extremity weakness associated with eating. Occlusion of the ipsilateral common carotid artery and stenosis or occlusion of the major collateral sources were demonstrated. We believe this anatomic configuration, combined with increases in demand for external carotid artery blood flow necessitated by the act of chewing, resulted in a vascular steal syndrome. An extended carotid endarterectomy was performed, and there were no additional episodes.  (+info)

Motor pattern specification by dual descending pathways to a lobster rhythm-generating network. (4/522)

In the European lobster Homarus gammarus, rhythmic masticatory movements of the three foregut gastric mill teeth are generated by antagonistic sets of striated muscles that are driven by a neural network in the stomatogastric ganglion. In vitro, this circuit can spontaneously generate a single (type I) motor program, unlike in vivo in which gastric mill patterns with different phase relationships are found. By using paired intrasomatic recordings, all elements of the gastric mill network, which consists mainly of motoneurons, have been identified and their synaptic relationships established. The gastric mill circuit of Homarus is similar to that of other decapod crustaceans, although some differences in neuron number and synaptic connectivity were found. Moreover, specific members of the lobster network receive input from two identified interneurons, one excitatory and one inhibitory, that project from each rostral commissural ganglion. Integration of input from these projection elements is mediated by synaptic interactions within the gastric mill network itself. In arrhythmic preparations, direct phasic stimulation of the previously identified commissural gastric (CG) interneuron evokes gastric mill output similar to the type I pattern spontaneously expressed in vitro and in vivo. The newly identified gastric inhibitor interneuron makes inhibitory synapses onto a different subset of gastric mill neurons and, when activated with the CG neuron, drives gastric mill output similar to the type II pattern that is only observed in the intact animal. Thus, two distinct phenotypes of gastric mill network activity can be specified by the concerted actions of parallel input pathways and synaptic connectivity within a target central pattern generator.  (+info)

Variation in ruminants' preference for tall fescue hays cut either at sundown or at sunup. (5/522)

Plants vary diurnally in concentrations of nonstructural carbohydrates. If ruminants prefer forages with higher total nonstructural carbohydrates (TNC), then the preference for hays harvested within the same 24-h period may vary. An established field of tall fescue (Festuca arundinacea Schreb.) was harvested six times in the vegetative stage. Harvests were paired such that each cutting at sundown (PM) was followed by a cutting the next morning at sunup (AM). We harvested in this manner three times, resulting in six hays. The hays were field-dried, baled, and passed through a hydraulic bale processor prior to feeding. Experiments were conducted with sheep, goats, and cattle, using six animals in each case. During an adaptation phase, hays were offered alone as meals. In the experimental phase, every possible pair of hays (15 pairs) was presented for a meal. Data were analyzed by multidimensional scaling and by traditional analyses. Multidimensional scaling indicated that selection was based on a single criterion. Preference for PM hays was greater than for AM hays (P < .01) in all experiments. Increased preference was associated with increased TNC (P < .01) and in vitro true DM disappearance (P < .01) and decreased fiber concentration (P < .01; NDF, ADF, cellulose, and ADL). Mowing hay late in the day was effective in increasing forage preference.  (+info)

Feeding problems in merosin deficient congenital muscular dystrophy. (6/522)

Feeding difficulties were assessed in 14 children (age range 2-14 years) with merosin deficient congenital muscular dystrophy, a disease characterised by severe muscle weakness and inability to achieve independent ambulation. Twelve of the 14 children were below the 3rd centile for weight. On questioning, all parents thought their child had difficulty chewing, 12 families modified the diet, and 13 children took at least 30 minutes to complete a meal. On examination the mouth architecture was abnormal in 13 children. On videofluoroscopy only the youngest child (2 years old), had a normal study. The others all had an abnormal oral phase (breakdown and manipulation of food and transfer to oropharynx). Nine had an abnormal pharyngeal phase, with a delayed swallow reflex. Three of these also showed pooling of food in the larynx and three showed frank aspiration. These six cases all had a history of recurrent chest infections. Six of eight children who had pH monitoring also had gastro-oesophageal reflux. As a result of the study five children had a gastrostomy, which stopped the chest infections and improved weight gain. This study shows that children with merosin deficient congenital muscular dystrophy have difficulties at all stages of feeding that progress with age. Appropriate intervention can improve weight gain and reduce chest infections. The severity of the problem has not been previously appreciated in this disease, and the study shows the importance of considering the nutritional status in any child with a primary muscle disorder.  (+info)

Cheek and tongue pressures in the molar areas and the atmospheric pressure in the palatal vault in young adults. (7/522)

The pressures acting on the maxillary and mandibular posterior teeth from the tongue and cheeks were measured in 24 adults aged 22-29 years. In addition, the pressure in the palatal vault was recorded. The pressure at two maxillary (buccal and lingual) and two mandibular (buccal and lingual) measuring points, and in the palatal vault was recorded simultaneously. Repeated recordings of the pressures at rest, and during chewing and swallowing were made. The pressures at rest were of similar magnitude (about 2 g/cm2) at the buccal and lingual sides of the mandibular posterior teeth. The median resting pressure at the maxillary posterior teeth was 2.7 g/cm2 on the buccal side and 1.0 g/cm2 on the lingual side. The difference in the maxilla was significant, but not in the mandible. It was concluded that the equilibrium of tooth position is maintained by the pressure from the cheeks and the tongue. During chewing and swallowing the pressures on the lingual side of the teeth were greater than those on the buccal side. At rest about half of the subjects had a negative pressure at the palatal vault, but no correlations between the resting pressure at the palatal vault and the resting pressures on the teeth were found.  (+info)

Features of cortically evoked swallowing in the awake primate (Macaca fascicularis). (8/522)

Although the cerebral cortex has been implicated in the control of swallowing, the output organization of the cortical swallowing representation, and features of cortically evoked swallowing, remain unclear. The present study defined the output features of the primate "cortical swallowing representation" with intracortical microstimulation (ICMS) applied within the lateral sensorimotor cortex. In four hemispheres of two awake monkeys, microelectrode penetrations were made at 5 mm deep to the cortical surface corresponding to both the white matter underlying the CMA and the frontal operculum; EMG patterns of swallows elicited from these four cortical regions showed some statistically significant differences. Whereas swallowing ONLY was evoked at some sites, particularly within the deep cortical area, swallowing was more frequently evoked together with other orofacial responses including rhythmic jaw movements. Increasing ICMS intensity increased the magnitude, and decreased the latency, of the swallow-related EMG burst in the genioglossus muscle at some sites. These findings suggest that a number of distinct cortical foci may participate in the initiation and modulation of the swallowing synergy as well as in integrating the swallow within the masticatory sequence.  (+info)

  • Saliva is released from glands under the tongue to aid in the process of mastication. (
  • The mastication causes a copious flow of saliva of a brick-red colour, which dyes the mouth, lips and gums. (
  • Mastication is the process of combining ground up food particles with naturally occurring saliva. (
  • Aim: The aim of this study was to investigate mean electrical activity and how the anterior, middle, and posterior portions of the temporalis muscle work during mastication. (
  • Electromyographic (EMG) recordings were made in anterior, middle and posterior portions of the temporalis muscle during mastication for 5 s. (
  • The wide movements of the mandible produced during mastication allow studying the integrated actions of the different portions of the temporalis muscle. (
  • The present study aimed to investigate how the anterior, middle, and posterior portions of the temporalis muscle work during mastication and to assess mean electrical activity of each portion in Angle's Class I individuals with the use of surface EMG. (
  • Mastication is the noun form of the verb masticate , meaning to chew or, less commonly, to reduce to a pulp by crushing or kneading, as is done in the rubber-making process. (
  • The mandible is the only bone that moves during mastication and other activities, such as talking. (
  • The mandible can close very strongly on the maxilla to perform the grinding and, furthermore, during mastication, can make lateral movements. (
  • Background: Some previous studies reported hearing ability can be reduced by impaired masticatory ability, but there has been little evidence reported of an association between hearing loss and unilateral mastication. (
  • Therefore, this study aimed to investigate the relationship between unilateral mastication (UM), estimated from individual functional tooth units (FTUs), and hearing loss in a representative sample of Korean adults. (
  • And while we're using technical words, remember that mastication is followed by deglutition -the process of swallowing. (
  • Mammalian mastication: a review of the activity of the jaw muscle and the movements they produce in chewing. (
  • Mastication Robotics: Biological Inspiration to Implementation is the first book in the special field of masticatory robots for applications including foods texture analysis, dental training and speech therapy. (
  • Mastication is a necessary preparation of solid aliment, without which there can be no good digestion. (
  • The total lipid potentially available for digestion in AB was 94.0%, which included the freely available lipid resulting from the initial sample processing and the further small amount of lipid released from the intact almond particles during mastication. (
  • VTT researchers are working to gain better understanding about the influence of food structure on mastication process and the consequences of these factors on disintegration of food matrix, starch digestion rate as well as on postprandial satiety. (
  • Understanding the effect of particle size and processing on almond lipid bioaccessibility through microstructural analysis: from mastication to faecal collection. (
  • Lipid release after mastication (8.9% from NA, 11.8% from RA, 12.4% from DA and 6.2% from AB) was used to validate our theoretical mathematical model of lipid bioaccessibility. (
  • 2016). Food texture and mastication have also been implicated in AHN and cognitive ability (Smith et al. (
  • 2016). Decreased mastication due to the removal of molars and edentulism in both humans and animals have a negative impact on AHN and associated cognition. (
  • Mastication is a technical word for the act of chewing. (
  • Mastication is most commonly used in a scientific or technical way, though people sometimes use it to be funny by choosing a technical word instead of just saying chewing. (
  • It is needed for mastication (chewing) and performs when it closes the jaws. (
  • This paper describes a method for obtaining detailed information about the velocities, directions and relative forces involved in mastication, and how these change throughout the chewing sequence, from combined electromyograph and kinematic records in human subjects. (
  • Mastication of apple and carrot relied on vertical compression for each chew, with decreasing effort applied over the course of the chewing sequence. (
  • Final product is a very important indicator for the efficiency of the mastication, and chewing pattern. (
  • The effect of increased mastication by daily gum-chewing on salivary gland output and dental plaque acidogenicity. (
  • The study, recently published in the journal Immunity , found that chewing food - otherwise known as mastication - can stimulate the release of T helper 17 (Th17) cells in the mouth. (
  • Mr. Casillas is giving us a great example of what is known as "False Mastication" or false chewing. (
  • Demonstration of chewing motor disorder by recording peripheral correlates of mastication. (
  • Implications of mastication in energy intake and expenditure regulated by histamine (HA) neurons were investigated in rats. (
  • Mastication-induced activation of HA neurons suppressed physiological food intake through H1-receptor in the hypothalamic paraventricular nucleus (PVN) and the VMH. (
  • Mastication thus plays an important role as a potent input signal to activate HA neurons. (
  • Neurons of the dorsal nucleus reticularis pontis caudalis (nPontc) fire rhythmically during fictive mastication, while neurons of the ventral half tend to fire tonically (Westberg et al. (
  • 2001). This paper describes the changes in the pattern of rhythmical mastication elicited by stimulation of the sensorimotor cortex during inhibition or excitation of neurons in this nucleus and adjacent parts of nucleus reticularis gigantocellularis (Rgc) in the anaesthetized rabbit. (
  • Injections of NMDA excited local neurons and when injected into ventral nPontc, it completely blocked mastication. (
  • Our findings suggest that neurons of ventral nPontc tonically inhibit other parts of the central pattern generator during mastication, while dorsal neurons have mixed effects. (
  • It was concluded (1) that the soleus H reflex is tonically facilitated during mastication and (2) that afferent impulses from intraoral mechanoreceptors are not indispensable for the facilitation. (
  • Although the relationship between mastication and brain function is potentially important, the mechanism underlying is not fully understood. (
  • Due to the development of the chipset technology and software programming, we have now device-based diagnostic tools, joint vibration analysis, joint tracking measuring mastication analysis, computer-based occlusal analysis devices, and so on [ 8 , 9 , 10 ] available. (
  • In their study, the team also found that long-term exposure to physiological damage caused by mastication can exacerbate the effects of periodontitis. (
  • In the present study, we quantified the lipid released during artificial mastication from four almond meals: natural raw almonds (NA), roasted almonds (RA), roasted diced almonds (DA) and almond butter from roasted almonds (AB). (
  • The aim of the present study was to test the influence of gentle mastication on the occurrence of endotoxemia in patients with or without periodontal disease. (
  • It is very interesting to note that in the context of a conversation however , should another display false mastication, it significantly increases the odds that this secondary to deception-related anxiety . (
  • Correlation of accelerometers with electromyograph in the mastication of pygmy goats ( Capra hircus ). (
  • Both animal and human studies indicate that mastication influences hippocampal functions through the end product of the hypothalamic-pituitary-adrenal (HPA) axis, glucocorticoid (GC). (
  • The aim of this study is to test the hypothesis that maternal active mastication influences the effect of prenatal stress on bone mass and bone microstructure in adult offspring. (
  • It is also suggested that further elucidation of the mechanism linking mastication and brain function can lead to novel treatments and preventive measures for memory/learning dysfunction in the future. (
  • During the fall of 2005, a study was conducted at Priest River Experimental Forest (PREF) in northern Idaho to investigate the economics of mastication used to treat activity and standing live fuels. (
  • And animals with different diets use different methods of mastication - carnivores (meat eaters) typically chew up and down, while herbivores (plant eaters) generally chew from side to side. (
  • Mastication is almost always used in a scientific or technical context. (
  • Extended bouts of periodic mastication and intermittent energy restriction (IER) may improve cognitive performance in the context of adult hippocampal neurogenesis in an ageing population. (
  • But thinning requires that the refuse (or slash) be removed from the site, which can be done either by burning it or by mastication and dispersal. (
  • We evaluated the applicability of mastication as a fuel treatment alternative within Northern Rocky Mountain moist and dry forests to treat post-harvest activity slash (moist forest) and standing trees (dry forest). (
  • On the moist forest site, we compared four different slash treatments, mastication, machine grapple piling, lop and scatter, and a control within a wildland urban interface setting to determine the effects of these treatments on soil nutrition, forest floor depth, and woody debris distributions. (
  • These findings indicate that maternal active mastication during prenatal stress can ameliorate prenatal stress-induced lower bone mass of the vertebra and femur in adult offspring. (
  • 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. (
  • Conclusions: Gentle mastication is able to induce the release of bacterial endotoxins from oral origin into the bloodstream, especially when patients have severe periodontal disease. (
  • Oh, I remember getting some reviews of the MASTICATION demos back then and a common comment was that demo one was a deviating original where as demo two was more inline with the style going on, that probably being the reason for why people remember the first demo rather than the second. (