Elastic activator for treatment of open bite.
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This article presents a modified activator for treatment of open bite cases. The intermaxillary acrylic of the lateral occlusal zones is replaced by elastic rubber tubes. By stimulating orthopaedic gymnastics (chewing gum effect), the elastic activator intrudes upper and lower posterior teeth. A noticeable counterclockwise rotation of the mandible was accomplished by a decrease of the gonial angle. Besides the simple fabrication of the device and uncomplicated replacement of the elastic rubber tubes, treatment can be started even in mixed dentition when affixing plates may be difficult. (+info)
Effects of repeated cold stress on activity of hypothalamic neurons in rats during performance of operant licking task.
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The present study investigated the effects of repeated cold stress on single neuron activity in the lateral hypothalamic area (LHA) and medial hypothalamic area (MHA) of behaving rats. The rats were trained to lick a protruding spout in response to one of several cue-tone stimuli (CTSs) to ingest water, or amino acid, NaCl or glucose solution. Following this training, the rats were raised under either stressed (repeated temperature changes between -3 and 24 degrees C) or control (24 degrees C) condition for 2 mo. During this period, neuronal activity was recorded in the LHA and MHA. For rats raised under the stressed condition, mean spontaneous firing rate of LHA neurons was significantly greater than for rats under the control condition. More LHA neurons in the stressed rats responded, with an accompanying decrease in activity (inhibitory response), to CTSs than in the control rats. During extinction learning, some LHA neurons enhanced or reversed the responses to CTSs in the stressed rats, whereas no LHA neurons showed such response changes in the control rats. In contrast to the effects of the stressed condition on LHA neuron activity, mean spontaneous firing rate of MHA neurons in the stressed rats was significantly smaller than in the control rats. Fewer MHA neurons in the stressed rats responded to CTSs and/or ingestion of sapid solutions. The preceding results suggested that repeated cold stress produces a specific pattern of changes in spontaneous activity and responses to sensory stimuli in LHA and MHA neurons; this could underlie the behavioral changes induced by repeated cold stress such as hyperphagia and hyper-reactivity to sensory stimuli. (+info)
A case of anterior open bite developing during adolescence.
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Imaging studies have reported on the relationship between temporomandibular joint (TMJ) degeneration and facial deformity. These studies have suggested that mandibular growth is affected by TMJ degeneration, resulting in altered skeletal structure as mandibular retrusion. However, there are very few longitudinal case reports on TMJ osteoarthrosis (OA). Progressive open bite occurred in an adolescent patient with TMJ OA. Cephalometric analysis showed a downward and backward rotated mandible, and a labial inclination of the upper incisor. Magnetic resonance imaging showed internal derangement without reduction and erosion in the right and the left condyles. Although the cause of open bite is unclear in this case, tongue thrusting, and internal derangements in the temporomandibular joint were suspected as causes of the open bite. (+info)
An evaluation of food type and texture in the treatment of a feeding problem.
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An evaluation of food type and texture indicated that both variables affected the expulsions of a 3-year-old with feeding problems. The results of the evaluation were used to prescribe a treatment (reducing the texture of one food type) that reduced expulsion. (+info)
Lip seal study of Japanese adults with malocclusion.
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The purpose of this study to clarify the factors an effecting lip seal in Japanese adults with malocclusion. Sixty-three malocclusion patients aged 20 to 27 years were randomly selected and compared with fourteen normal occlusion controls aged 22 to 26 years old. The subjects were divided into a good seal group and a poor lip seal group by observing the distance between the upper and lower lip at rest. Results of this adult study were as follows; There were no poor lip seals in normal occlusion subjects. Significant differences were observed for tongue thrust (p < 0.05) and mouth breathing (p < 0.05) between the good lip seal group and poor lip seal group of malocclusion subjects. Adults with poor lip seal should be treated for their malocclusion prior to be other functional approaches to improving their lip seal. (+info)
Malocclusion associated with abnormal posture.
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Growth and development of maxillofacial morphology and oral function are closely interrelated. Oral function is comprised of articulation, swallowing, and chewing. Malocclusion may be caused by abnormal functions such as mouth breathing, tongue thrust swallowing, and unilateral chewing and by abnormal postures of oral circumferential muscles such as forward tongue thrust, tongue biting, and low tongue at rest. Forces from unintentional and habitual behaviors constantly acting on the maxillofacial and alveolar regions can cause the bony structures to generally deform, resulting in jaw deformity and malocclusion. Oral function also plays a vital role in maintaining body posture. In this study, clinical observations of oral postures examined maxillary protrusion and open bite, anterior crossbite and facial asymmetry. The unstable forces induced by abnormal posture were correlated with the varieties of malocclusion. Morphology, function, and posture were shown to be closely interrelated and to influence each other. (+info)
A cineradiographic study of deglutitive tongue movement in patients with anterior open bite.
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The purpose of this study was to use cineradiographic images to investigate tongue movement during deglutition in anterior open bite patients with tongue thrust. Each subject had semi-spherical lead markers attached to the tip and dorsal surface of the tongue and was asked to swallow 5 ml of diluted liquid barium. Tongue movement during deglutition was recorded in the mid-sagittal plane with an X-ray VTR system. The deglutition process was divided into 6 stages to analyze the movements of the tip and dorsal surface of the tongue in each stage. In open bite patients, both the tip and dorsum of the tongue were positioned anteriorly and inferiorly at rest and during the buildup of negative intraoral pressure. The dorsum of the tongue tended to move and be positioned anteriorly as the tongue tip protruded and pushed the maxillary and mandibular anterior teeth. The tongue tip traveled a significantly smaller distance from the stage of tongue rest position to that of most retruded tongue tip position and a significantly larger distance from the stage of most retruded tongue tip position to that of tongue tip fixation in open bite patients than in controls. (+info)
Oral habits of temporomandibular disorder patients with malocclusion.
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The purpose of this study was to clarify the relationship between oral habits and symptoms of temporomandibular joint disorder in patients who had sought orthodontic treatment by analyzing their present and past history. The subjects were 57 female patients (average age: 23 years and 6 months old) who had visited the "Temporomandibular Disorder Section" in our orthodontic department. Their chief complaints were the symptom of TMJ and the abnormalities of occlusion such as maxillary protrusion, open bite, crowding, mandibular protrusion, cross bite, deep bite, edge-to-edge bite, and spacing. Their present conditions and past histories were examined and evaluated. The most typical primary symptom was joint sound (23 patients, 40.0%). The second was joint sound and pain (15 patients, 26.3%). Of the symptoms present at the time of examination, the most prevalent were joint sound and pain (20 patients, 35.1%). The 48 patients (82.8%) had significant oral habits. Unilateral chewing was seen in 35 patients (72.9%), bruxism in 27 (56.3%), abnormality of posture in 14 (29.2%), habitual crunching in 10 (20.8%) and resting the check on the hand in 4 (8.3%), respectively. When comparing the primary symptoms to those at the time of examination, the patients with unilateral chewing and bruxism tended to have more complicated symptoms. In conclusion, the TMD symptoms of the patients with notable oral habits did not change or become worse during a period of about 5 years. (+info)