scholarly journals Masticatory Function and Maturation of the Jaw-Opening Reflex

2009 ◽  
Vol 79 (2) ◽  
pp. 299-305 ◽  
Author(s):  
Chidsanu Changsiripun ◽  
Tadachika Yabushita ◽  
Kunimichi Soma

Abstract Objective: To test the null hypothesis that alteration in masticatory function due to liquid-diet feeding during growth does not affect jaw-opening reflex (JOR) maturation. Materials and Methods: Soon after weaning, 70 female Wistar rats were divided into two equal groups and fed either solid (control group) or liquid (experimental group) diets. At 5, 9, and 13 weeks, the rats were anesthetized and the JOR was recorded in the anterior belly of the digastric muscles as evoked by a low-intensity electrical stimulation of the left inferior alveolar nerve. Results: There were similar tendencies at each recording age. Peak-to-peak amplitude of the JOR was significantly smaller, and the latency was significantly longer in the experimental group, although the duration was not significantly different between the two groups. Conclusions: These data suggest that long-term masticatory functional change due to liquid-diet feeding during growth may impede the learning for JOR maturation, and thus may affect the masticatory performance in the adult.

2021 ◽  
Vol 6 (6) ◽  
pp. 259-266
Author(s):  
I. I. Kolosova ◽  
◽  
L. Yu. Bogomolna ◽  
G. Yu. Chriss ◽  
N. N. Tereshchenko ◽  
...  

Given the increase in cadmium in the environment (air, soil, water) through modern industrial processes, the absorption of significant amounts from cigarette smoke is relevant to studying the effect of cadmium compounds on embryogenesis. The purpose of the study: experimental study and comparison of embryolethality and embryotoxicity of metal citrates depending on the duration of their intragastric administration (during 13 and 20 days of gestation). Materials and methods. The study was performed on 120 white adult female Wistar rats that weigh 170-200 g. They were divided into 6 groups due to the intragastric administration of solutions of the studied metals – rats treated with citrates: cadmium at a dose of 1.0 mg/kg – 1st group (nfemale = 20, nemb = 166); cadmium at a dose of 1.0 mg/kg and cerium (1.3 mg/kg) – 2nd group (nfemale = 20, nemb = 185); cadmium in a dose of 1.0 mg/kg and germanium (0.1 mg/kg) – 3rd group (nfemale = 20, nemb = 184); cadmium at a dose of 1.0 mg/kg and zinc (1.5 mg/kg) – 4th group (nfemale = 20, nemb = 179); cadmium at a dose of 1.0 mg/kg and nanocomposite (iodine + sulfur + selenium) at a dose of 2.0 mg/kg – 5th group (nfemale = 20, nemb = 180), 6th group – control (nfemale = 20, nemb = 212) – proportional volume of sterile saline in the same way. Females were divided into 2 subgroups of 10 animals each, depending on the duration of administration of test substances. The embryotoxic and embryolethal effects of the test substances were evaluated according to generally accepted criteria, which were calculated according to well-known formulas. Results and discussion. Cadmium compounds harm the embryogenesis of rats in the experimental groups and increase the rates of embryolethality. The most pronounced differences in these parameters concerning the control were found in animals with isolated exposure to cadmium citrate: the rates of total embryonic mortality increased by 4.0 times in both study periods of embryogenesis and 20% from the 13th to the 20th day; increased pre-implantation mortality by 6.0 times with an increase in post-implantation mortality by 3 times on the 13th day and by 15.0 times and 2.8 times on the 20th day of embryogenesis, respectively. Depending on the duration of introduction, the indicators of pre-implantation mortality increased by 25.0% with an increase in post-implantation mortality by 22.2% in the same period. The experimental group of exposure to cadmium citrate at a dose of 1.0 mg/kg recorded the lowest indicators of the number of live fetuses and intrauterine survival with the highest resorption rate studied of embryonic development. At the same time, in the groups of combined exposure to cadmium citrate with metal citrates, a decrease in the indicators of total embryonic mortality was 50.0% - 30.0%, pre-implantation mortality – 50.0% - 25.0%, post-implantation mortality – 60.0% - 44.4 % and increase in the number of fetuses per female – 12.7% - 25.3%. Conclusion. Analysis of the results shows a pronounced embryotoxic effect of cadmium citrate at a dose of 1.0 mg/kg on the processes of embryogenesis, which is a significant increase in overall embryonic mortality, preimplantation, and postimplantation mortality compared with the control group in all studied terms. In the groups of combined action of cadmium citrate with metal citrates, the data obtained indicate a decrease in the accumulation of cadmium under the influence of the studied citrates, which allows them to be considered as potential bioantagonists of cadmium citrate


2003 ◽  
Vol 14 (3) ◽  
pp. 172-176 ◽  
Author(s):  
Soraya Coelho Leal ◽  
Orlando Ayrton de Toledo ◽  
Ana Cristina Barreto Bezerra

The purpose of this study was to analyze the morphological alterations that occurred in the parotid glands of rats maintained on a liquid diet compared to a solid diet. Thirty-six animals were randomly divided into two groups. The control group received a solid diet, and the experimental group received a liquid diet. The animals were killed after 8, 15 and 30 days. The glands were prepared for inclusion in paraffin and analyzed with a light microscope. The results showed a statistically significant reduction of the parotid gland weight of the animals from the experimental group compared to the control group at 15 and 30 days. The strongest morphological alteration displayed was the presence of cytoplasm vacuoles on the parotid glands of the animals maintained on the liquid diet. Specific stain techniques for glycoproteins and mucopolysaccarides could not identify the substances inside the vacuoles observed in the experimental animals. We conclude that a liquid diet caused atrophy of the parotid gland after 15 and 30 days.


2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Jie Lin

Background: To compare the analgesic effect and safety of bilateral inferior alveolar nerve block combined with parecoxib sodium analgesia and simple intravenous analgesia pump in analgesia after orthognathic surgery. Methods: Forty patients with simple ascending sagittal split osteotomy and ankle plasty were randomly divided into the experimental group and the control group, with 20 patients in each group. The experimental group received 2 ml 1% on both sides. Ropivacaine was treated with inferior alveolar nerve block anesthesia. Immediately after surgery, parecoxib sodium 40 mg was intravenously administered. The control group was given an intravenous analgesia pump for analgesia. Pain intensity (VAS pain score) and Ramsay sedation score were recorded at 2h, 4h, 8h, 24h, 48h after operation, and the incidence of postoperative adverse reactions was observed. Results: There was no significant difference in pain intensity and Ramsay sedation score between the two groups at each time point (P>0.05). During the analgesic treatment, the incidence of nausea and vomiting (P=0.046) in the experimental group was significantly lower than that in the control group (P<0.05). Conclusion: Bilateral inferior alveolar nerve block combined with parecoxib sodium analgesia and simple intravenous analgesia pump are effective for analgesia after mandibular orthognathic surgery, but the incidence of adverse reactions is significantly lower, more suitable for Analgesia after mandibular orthognathic surgery.


2018 ◽  
Vol 17 (1) ◽  
Author(s):  
Rosa Baldeon-Gutierrez

Objetivo: Comparar el efecto anestésico de la técnica infiltrativa del nervio mentoniano con la técnica troncular del dentario inferior en terapiapulpar de la primera molar primaria mandibular en odontopediatría. Metodología: La muestra estuvo conformada por 16 pacientes (11 niñosy 5 niñas) divididos en grupo de estudio (anestesia infiltrativa mentoniana) y grupo control (troncular dentario inferior) ambos con (n=8).Se empleó un diseño de investigación experimental basado en observación estructurada con la escala de Houpt modificada solo para llantoy movimiento y encuesta estructurada a partir de la escala analoga visual. Resultados: Los datos se analizaron mediante el paquete estadísticoSPSS versión 22, donde se observó que el grupo experimental tuvo un valor estadístico muy similar al grupo control reportando valores de p de 1.00. El 87.5% no manifestó dolor a la apertura y en la escala analoga visual un 62.5% no manifestó ninguna molestia. Conclusiones: Ambas técnicas resultaron conferir un buen efecto anestésico durante la apertura cameral, por lo que se puede confirmar que la técnica infiltrativa mentoniana es util para la anestesia pulpar solo de la primera molar primaria mandibular, tal como se reporta en otras investigaciones.  Palabras clave: Anestesia dental, pulpotomia, odontología pediátrica. Abstract Objective: To compare the anesthetic effect of infiltrative technique of mental nerve with the nerve block technique inferior alveolar nerve for pulp therapy of the first mandibular molar decidua in children. Material and Methods: The sample consisted of 16 patients (11 boys and 5 girls) divided into a study group (infiltrative mentonian anesthesia) and control group (alveolar nerve block) both with (n = 8). We used an experimental research design based on structured observation with the Houpt scale modified only for crying and movement and a structured survey based on the visual analogue scale. Results: Data were analyzed using the statistical package SPSS version 22, where it was observed that the experimental group had a statistical value very similar to the control group reporting p values of 1.00. 87.5% did not show pain at the opening and in the visual analog scale 62.5% did not show any discomfort. Conclusions: Both techniques were found to confer a good anesthetic effect during chamber opening, so it can be confirmed that the infiltrative mentonian technique is useful for pulpal anesthesia only of the primary primary mandibular molar, as reported in other studies. Keywords: dental anesthesia, infiltration, pulpotomies, pediatric dentristy.


2012 ◽  
Vol 27 (1) ◽  
pp. 01-06 ◽  
Author(s):  
Érika Malheiros Bastos ◽  
Miguel Sabino Neto ◽  
Élvio Bueno Garcia ◽  
Daniela Francescato Veiga ◽  
Yuri Anna Han ◽  
...  

PURPOSE: To evaluate the effect of zafirlukast on capsular contracture around silicone implants by measuring the pressure within the implant, using a rat experimental model. METHODS: Forty adult female Wistar rats were used. Each one received two silicone implants, one with smooth-surface and the other with textured-surface. They were randomly divided into four groups (n=10). The rats of control group I were sacrificed after the implants. The remaining animals were subjected to a daily regimen of intra-peritoneal injection for a period of 90 days and they were distributed as follows: control group II received 0.9% physiological saline solution; experimental group I received zafirlukast 1.25 mg/kg; and experimental group II received zafirlukast 5 mg/kg. The measurement of intra-implant pressure of control group I was determined on the surgery day and in other groups on the ninetieth day, after being sacrificed. RESULTS: In the evaluation of textured implants there was an increase of internal pressure in the control group II, and there was no increase in the experimental groups. Compared to the controls there were not significant differences in smooth implants. CONCLUSION: Zafirlukast reduced the risk of developing capsular contracture around silicone implants with textured surface.


Author(s):  
D.C. Dominguez ◽  
J.T. Ellzey

Peroxisomes which participate in 1ipid metabolism have been shown to be altered in several metabolic disorders and toxic conditions. In alcoholic liver disease, the single lesion most frequently found is lipid accumu1ation in hepatocytes. However, the mechanisms for this 1ipid accumu1ation are not clear. The occurrence of modifications of liver peroxisomes due to excess alcohol consumption has not been subjected to a controlled study. We utilized a combination of cytochemica1 and morphometrictechniques to study the size and number of liver peroxisomes in rats fed an alcohol-supplemented diet compared to those of matched-paired control animals.Male Sprague-Daw1ey rats (400-500 g) received a liquid diet. The experimental group (N = 5/group) was fed a diet containing 30% ethanol-derived calories (EDC) and the control group was fed an isocaloric diet to 30% EDC. A pair feeding procedure was employed to control for caloric intake. Small pieces of liver randomly selected, were fixed in 2.3% -glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.2, incubated in a DAB medium and postfixed with. 2% aqueous osmium tetroxide. EM photographs were taken from sections of 3 tissue blocks from each sample (7,200X) with a Zeiss EM10-A (60 kV). With the use of a point counting method and a digital planimeter the volume density (Vv) and numerical density (Nv) were determined.


1999 ◽  
Vol 58 (4) ◽  
pp. 263-272
Author(s):  
Jörg Doll ◽  
Michael Dick

The studies reported here focus on similarities and dissimilarities between the terminal value hierarchies ( Rokeach, 1973 ) ascribed to different groups ( Schwartz & Struch, 1990 ). In Study 1, n = 65 East Germans and n = 110 West Germans mutually assess the respective ingroup and outgroup. In this intra-German comparison the West Germans, with a mean intraindividual correlation of rho = 0.609, perceive a significantly greater East-West similarity between the group-related value hierarchies than the East Germans, with a mean rho = 0.400. Study 2 gives East German subjects either a Swiss (n = 58) or Polish (n = 59) frame of reference in the comparison between the categories German and East German. Whereas the Swiss frame of reference should arouse a need for uniqueness, the Polish frame of reference should arouse a need for similarity. In accordance with expectations, the Swiss frame of reference significantly reduces the correlative similarity between German and East German from a mean rho = 0.703 in a control group (n = 59) to a mean rho = 0.518 in the experimental group. Contrary to expectations, the Polish frame of reference does not lead to an increase in perceived similarity (mean rho = 0.712).


Author(s):  
J. Santoantonio ◽  
L. Yazigi ◽  
E. I. Sato

The purpose of this study was to investigate the personality characteristics in adolescents with SLE. The research design is a case-control study by means of the Rorschach Method and the Wechsler Intelligence Scale. Study group: 30 female adolescents with lupus, 12–17 years of age. The SLE Disease Activity Index was administered during the period of psychological evaluation. Control group: 32 nonpatient adolescents were matched for age, sex, and socioeconomic level. In the Wechsler Intelligence Scale the mean IQ of the experimental group was significantly lower than that of the control group (77 and 98, respectively, p < .001). In the Rorschach, the lupus patients showed greater difficulty in interpersonal interactions, although they displayed the resources to process affect and to cope with stressful situations. A positive moderate correlation (p = .069) between the activity index of the disease and the affect constriction proportion of the Rorschach was observed: the higher the SLEDAI score, the lower the capacity to process affect. There is a negative correlation between the activity index of the disease and the IQ (p = .001): with a higher activity index of the disease, less intellectual resources are available.


Author(s):  
Leonard Reinecke ◽  
Sabine Trepte

Abstract. This quasi-experimental study examined the effects of exposure to a computer game on arousal and subsequent task performance. After inducing a state of low arousal, participants were assigned to experimental or control conditions via self-selection. Members of the experimental group played a computer game for five minutes; subjects in the control group spent the same amount of time awaiting further instructions. Participants who were exposed to the computer game showed significantly higher levels of arousal and performed significantly better on a subsequent cognitive task. The pattern of results was not influenced by the participants' prior experience with the game. The findings indicate that mood-management processes associated with personal media use at the workplace go beyond the alteration of arousal and affect subsequent cognitive performance.


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