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At least 1,369 records · Page 76Linked to original sources
PubMed1999

Effect of chewing gum on recovery after tonsillectomy.

OBJECTIVE: Patients are traditionally advised to eat early and frequently in the initial post-tonsillectomy period to reduce the severity of pain and to facilitate early resumption to a normal diet. We investigated the action of mastication and therefore the promotion of saliva formation and deglutition on the post-operative recovery of tonsillectomy patients. METHODS: We present a prospective randomised controlled trial set up to observe the effects of chewing gum on these patients. One hundred and two patients undergoing routine tonsillectomy for recurrent tonsillitis were randomised into cases (those given chewing-gum) and control groups (those not given chewing-gum). Eighty-four patients were reviewed on the seventh post-operative day. We measured the time taken in days for the subjects to resume to their normal diet after surgery and measured pain on a daily basis. RESULTS: Our study demonstrated that chewing gum in the early post-operative period significantly delayed resumption of normal diet (Chi-squared test with Yates' correction, chi2= 4.6, P = 0.032). Chewing gum also increased the average amount of pain experienced by the cases over the controls and this became statistically significant on day 7 (mean difference = 14.8, t-test with two tailed probability, P = 0.041). CONCLUSION: We conclude that chewing gum should not be routinely advised in the early period following tonsillectomy.

Adolescent↗
PubMed1994

Statistics of differential Lissajous EMG for normal occlusion and Class II malocclusion.

Differential Lissajous electromyography (DL-EMG), a method of representing the simultaneous EMG values of two paired muscles as a single, continuous figure, was used in chewing tests with a sample of Japanese women having normal occlusion compared with a like group of Japanese female adolescents, having Class II, Division 1 malocclusion. For the normal sample, the DL-EMG figures described by the coordinated activity of the bilateral temporal and masseter muscles during chewing gum mastication typically appeared as repetitions of loops. Statistical data were gathered on the total EMG voltages, and on the location, rotational direction, and orientations of the DL-EMG loops when graphed onto Cartesian coordinates. These data were compared with those taken from the Class II sample. Significant differences were observed in the latter group for the EMG voltage levels of the balancing-side masseter muscles. The DL-EMG figures of the Class II group also showed irregularities in the shapes, locations, rotational directions, and orientations of the loops, indicative of irregular masticatory patterns. These data suggest that with sufficient control of factors such as age and sex, electromyography and especially DL-EMG techniques can be useful for characterizing masticatory differences between various occlusal groups.

Adolescent↗
PubMed1998

Reactions of peri-implant tissues to continuous loading of osseointegrated implants.

Functional and morphologic reactions of peri-implant bone surrounding screw implants (Bonefit) were studied in three dogs by loading the implants with continuous forces of 2 (about 204 gm) and 5 N (about 510 gm). Eight implants were inserted to an endosseous length of 12 mm and placed about 10 mm apart in the region of the lower premolars. The fixtures healed in a closed environment for 12 weeks, after which they were uncovered and loaded with abutments and orthodontic devices to produce horizontal distraction with a force of 2 N (about 204 gm) for 12 weeks. Subsequently they were loaded with 5 N (about 510 gm) for another 24 weeks. The distance between and the mobility of the implants were determined before and after each phase of experimental loading. Fixtures of the same type that were osseointegrated and not exposed, or osseointegrated and loaded by mastication, were used as a control. Animals were euthanized and specimens sectioned. The result was that continuously loaded implants showed no significant displacement for any force level. The mobility of the fixtures increased slightly by about 1 Periotest-value (PTV) at the end of the experiment. No significant peri-implant pocket could be seen in implants loaded by continuous or masticatory forces. Histologic and morphometric evaluation indicated compaction of bone as a result of loading. Osseointegrated implants have potential as a firm osseous anchorage for orthodontic treatment and can resist continuous horizontal forces of at least 5 N (about 510 gm) during a period of several months.

Absorptiometry, Photon↗
PubMed1987

Clinical course and evaluation of shape and function after reconstruction using various pedicle flaps for oral and maxillofacial defects.

In the past 7 years, reconstruction using various pedicle flaps for oral and maxillofacial defects, was carried out for 40 patients. Pectoralis major myocutaneous, deltopectoral and scalp-forehead flaps for large defects, and sternocleidomastoid, cervical island skin and palatal flaps for moderate defects were indicated. As for results, most of the flaps used at the reconstructed site for the defects of soft tissue repaired the shape and patients were satisfied. However, the recovery of functions concerning speech, swallowing or mastication was not always successful with the larger defects, especially after the reconstruction for defects of tongue, floor of the mouth, cheek and mandible for which mandibular reconstruction was performed. It was pointed out that the main causes for less tongue mobility were due to scar contracture after reconstruction, and difficulty of mandibular reconstruction due to postoperative infection were associated factors. Accumulated survival rate of patients for 5 years was 62.6%, in which 38 advanced malignant tumors were reconstructed following surgery. In the clinical course after reconstruction, patients with primary tumors experienced much better results than those with secondary tumors.

Adult↗
PubMed1993

Evaluation of mandibular fracture treatment.

A total of 124 patients treated for mandibular fractures were analyzed. Patients were divided into three groups according to treatment: intermaxillary fixation, wire fixation and mini-plate fixation. For each method, the success of treatment was evaluated with respect to surgical approach, fracture site and injury to treatment interval. Five basic parameters were used for evaluation of the outcome: occlusion, appearance, mastication, duration of IMF and complications. The treatment was surveyed based on both the surgeon's and patient's-evaluation. All parameters were scored and average values for every parameter calculated. The most successful treatment was achieved with mini-plate fixation in symphyseal and angle fractures. Intermaxillary fixation is indicated for mandibular body fractures with or without minimal displacement and a sufficient number of teeth. However, mini-plate fixation should be used for fractures with displacement. Wire fixation has been shown to be the poorest choice for all sites. Results showed that the intraoral approach has advantages over the extraoral one. The optimal time for treatment of mandibular fractures is within 72 h from time of injury. Even in fractures older than 7 days we recommended mini-plate fixation.

Adult↗
PubMed2001

Development of a three-dimensional jaw-tracking system implanted in the freely moving mouse.

A high-resolution mandibular tracking system was designed and tested in a freely moving mouse. A sensor unit, which consisted of four small magnetic sensors, was employed to trace small magnet movements in the three-dimensional space. After the sensor's output-to-displacement transformation equations were obtained from a multiple regression analysis of pre-experimental calibration data, the magnet and the sensors were transferred to the mouse, being kept at the same configuration as determined in the calibration system. In order to measure the three-dimensional jaw movements, the magnet was glued on the mandibular surface of the mouse and the sensor unit was implanted in the nasal bone. Jaw-movement trajectories were obtained as electrical signals from the sensors after being compensated by the output-to-displacement transformation equations of the sensors with a personal computer. This sensor system, applied to the freely moving mouse, could trace the jaw trajectories with an accuracy of better than 20 microm in three-dimensional space. Consequently, the typical pattern of the rhythmical jaw movements of the mouse during mastication was obtained. The mouse protruded the mandible to the most anterior position in the jaw-opening phase and retruded to it the most posterior position in the jaw-closing phase. This tracking system may also be applied to other small animals.

Animals↗
PubMed2006

Release and perception of ethyl butanoate during and after consumption of whey protein gels: relation between textural and physiological parameters.

The influence of gel texture on parameters such as positioning of food material in the oral cavity during mastication, and salivation, and their influence on aroma release in vivo was studied. Retronasal perception was followed by means of time-resolved sensory evaluation, while volatile release patterns were observed by means of PTR-MS. A clear correlation was found between individual-specific consumption patterns and the respective sensory perception. Also, gel texture could be clearly correlated with respective physicochemical release patterns in vivo and to the corresponding retronasal aroma perception.

Adult↗
PubMed2000

Within-subject comparison of maxillary long-bar implant-retained prostheses with and without palatal coverage: patient-based outcomes.

Although maxillary implant overdentures are used in oral rehabilitation, different designs have not been compared previously in clinical trials. This crossover trial was designed to measure differences in patient satisfaction with maxillary long-bar implant overdentures with and without palatal coverage opposed by a fixed mandibular implant-supported prosthesis. Data were also gathered on new conventional dentures and on maxillary conventional dentures opposed by mandibular fixed prostheses. Sixteen participants were selected from a population wearing conventional dentures. Fifteen received new upper and lower dentures (1 drop-out). Four implants were placed in the maxilla and mandible (2 drop-outs). A mandibular fixed prosthesis was inserted in 13 participants, who were then divided into 2 groups. One group (n = 7) received long-bar overdentures with palate, then long-bar overdentures without palate. The other group (n = 6) received the same treatments in the reverse order. Mastication tests and psychometric evaluations using Visual Analog Scales and Categorical Scales were performed throughout the study. General satisfaction was very high with both maxillary implant-supported prostheses, as were ratings of almost all psychosocial and functional variables. There were no significant differences between treatments, suggesting that patients are equally satisfied with long-bar overdentures with and without palate when these are opposed by mandibular fixed prostheses. However, the ratings given to the maxillary implant prostheses were not significantly higher than for new conventional maxillary prostheses. This suggests that maxillary implant prostheses should not be considered as a general treatment of choice in patients with good bony support for maxillary conventional prostheses.

Adult↗
PubMed2000

Tongue piercing and associated oral and dental complications.

The insertion of metal objects into intraoral and perioral sites is growing in popularity. However, there are numerous oral and dental complications associated with tongue piercing. Fifteen patients with tongue piercings (pierced in the body of the tongue, anterior to the lingual frenum) attending the dental office of the authors, with and without complaints, were clinically and radiographically examined. The most common dental problem registered was chipping of teeth. Furthermore, two cracked teeth and four teeth with cusp fractures were also seen. One case of selective dental abrasion was registered. Trauma to the lingual anterior gingiva was the most common gingival problem. A salivary flow stimulating effect was only reported by 2 of the 15 individuals. None of the patients complained of interference with speech, mastication and swallowing. One case of galvanic currents produced by the appliance was registered. On the basis of the registered data, we concluded that patients need to be better informed of the potential complications associated with tongue and oral piercings, and that the dental profession can serve this role.

Adult↗
PubMed1981

Trigeminal deafferentation and ingestive behavior in rats.

For studying the role of orosensory input in the control of ingestive behavior, rats were subjected to varying degrees of trigeminal deafferentation. Somatosensory branches that convey touch, temperature, and pain from the oral cavity were sectioned selectively, and innervation of the muscles of mastication and taste afferents were left intact. Severe intake deficits were produced, which included aphagia, adipsia, and prolonged hypophagia accompanied by a corresponding decrease in body weight. The deficits were proportional to the extent of deafferentation and were most severe when upper and lower portions of the mouth were affected. Although somatosensory impairment affected the organization of the consummatory response, all rats could bite, chew, and lick. Analysis of feeding patterns of minimally (mandibular) deafferented rats showed that the animals compensated for the consummatory inefficiency by increasing meal duration but failed to initiate meals at the normal rate, thus keeping food intake below normal levels. These results suggest that oral somatosensory input is critical for the mechanisms that regulate ingestive behavior.

Afferent Pathways↗
PubMed2005

Marginal adaptation of different types of all-ceramic partial coverage restorations after exposure to an artificial mouth.

OBJECTIVES: To determine the influence of the preparation design and the dimensions of all-ceramic partial coverage restorations (PCR) on the marginal accuracy before and after masticatory simulation. METHODS: In this in vitro study 80 extracted human maxillary molars were restored with MOD inlay restorations and four different modified PCR restorations using a new press ceramic IPS e.max Press (IPS e.max Press VP 1989). The teeth were divided into five groups of 16 specimens each and prepared as follows: Group A received an MOD inlay preparation and Group B, C, D and E received modified PCR. The restorations were adhesively luted and exposed to a mastication simulator. The discrepancies of the marginal fit were examined on epoxy replicas before and after luting as well as after masticatory simulation at 200x magnification. RESULTS: The mean (geometrical) [95% confidence limits] marginal gap decreased from Group A to E before cementation (A-83[77-90]microm, B-68[65-70]microm, C-59[55-64]microm, D-56[52-61]microm, E-50[45-55]microm). Group A had significantly higher marginal gap values than group B (p = 0.017) and the other groups (p<0.0001). After cementation the marginal accuracy was recorded as following: A-103[93-114]microm, B-101[94-108]microm, C-93[89-98]microm, D-102[98-105]microm and E-99[96-102]microm. Cementation increased the marginal gap in groups B-E significantly (p<0.00001), not significantly in group A (p = 0.059). Artificial ageing (A-116[106-127]microm, B-114[109-120]microm, C-106[103-110]microm, D-109[100-118]microm and E-109[105-112]microm) led to further significant decrease of marginal accuracy in Group B (p = 0.029) and C (p = 0.026) only. After cementation and masticatory simulation of the ceramic restorations, the marginal gap values of Groups A, B, C, D and E did not significantly differ from each other (p = 1.00). CONCLUSIONS: The result of this in vitro study showed that IPS e.max Press can be used to fabricate all-ceramic inlays and PCR which meet the requirements in terms of a clinically acceptable marginal gap, irrespective of the preparation design used. However, the preparation design and dimensions of the restorations appeared to affect the initial marginal fit and flowing off of luting material during the cementation process. The factors responsible for these findings require further substantiation.

Aluminum Silicates↗
PubMed2005

Masticatory demands induce region-specific changes in mandibular bone density in growing rats.

This study investigates the structural adaptation of the mandibular bone when subjected to different masticatory functional and mechanical demands during growth. The effect of two experimental factors, the insertion of a bite block and the alteration of food consistency, on the bone mineral density (BMD) of the mandible was investigated in growing rats. Fifty-two male albino rats were divided into two equal groups, fed with either the standard hard diet or soft diet, at the age of four weeks. After two weeks, half the animals in both groups had their upper molars fitted with an upper posterior bite block. The remaining animals served as a control. Region-specific BMD of the mandible was subsequently measured using dual-energy X-ray absorptiometry (DXA). Soft diet and the consequent reduction of the forces applied to the mandible during mastication resulted in the reduction of BMD in all regions under study. The insertion of the bite-opening appliance (bite block) and the resulting stretching of the soft tissues led to the application of a continuous light force on the lower molars, which was associated with a significant increase of the BMD in the part of the alveolar process just below the root apices. These results raise the question of whether orthodontic treatment with similar appliances may have some, previously unsuspected, short- or long-term effects on the mandibular bone during growth and whether their effects depend on the individual soft-tissue characteristics.

Absorptiometry, Photon↗
PubMed2005

Persistence of respiratory-swallowing coordination after laryngectomy.

The present study was designed to provide additional insights into the neural mechanisms underlying respiratory-swallowing coupling by studying potential alterations in movement coordination when upper airway protection is no longer necessary. Twelve laryngectomized participants, all at least 3 years postsurgery, were compared to age- and sex-matched controls. Respiration and swallowing were monitored before, during, and after mastication. No significant differences were found between the laryngectomized and normal control participants in the distribution of the respiratory phase in which swallowing occurs, our primary measure of respiratory-swallowing stability. Data suggest that the coupling between the swallowing and respiratory pattern generators is highly stable. Pronounced masticatory-related apnea was observed in 3 of the laryngectomized participants but in none of the controls, suggesting that masticatory/respiratory interactions may become abnormal in these patients.

Adult↗
PubMed2000

Denture satisfaction and clinical performance in a paediatric population.

OBJECTIVES: The objectives of this study were to investigate the clinical performance of partial upper dentures in children and to assess reported denture satisfaction in this young population. DESIGN: This was a retrospective study using patients' dental records in conjunction with a postal questionnaire. SETTING: The Paediatric Dentistry Clinic, School of Clinical Dentistry, Sheffield. SAMPLE AND METHODS: Fifty-eight children (aged 7-17 years) who had been provided with a partial upper denture to replace one or more missing permanent incisors were included in the study. The patients' dental records were examined for the following details: tooth type missing, presence of retained incisor roots, aetiology of tooth absence, age at which the denture was first provided, total time period dentures had been worn, and frequency and type of any denture repairs or replacements. Next a short questionnaire was sent to each child, which sought an evaluation of several parameters of denture satisfaction including: overall attitude towards wearing a denture, denture appearance, ease of eating, comfort and perceived degree of teasing from peers. Visual analogue scales (VAS) were employed to provide a graded response. RESULTS: 70.7% of subjects had a single missing incisor and trauma was the most common cause of tooth loss (77.3%). The mean age at which patients started wearing a denture was 11.6 years and the mean length of time dentures had been worn, at the time of the investigation, was 2.1 years. A 'T-shaped' denture was most commonly employed (77.5% of dentures). Overall, 36.2% of subjects had required at least one denture repair, 28.2% presenting within a year of denture provision. One or more denture replacements had been received by 60.3% of the patients, and 43.6% had required this within a year. Component failure was highest for the denture tooth (40% of repairs) and a change in the patient's dentition necessitated a denture remake in 66% of cases. VAS scores for parameters of denture satisfaction indicated an overall positive evaluation of the dentures, with the most positive response relating to ease of eating. However, the reported degree of teasing was high and increased with time. The only significant difference for denture satisfaction according to gender was for mastication: girls reportedly found eating easier than did boys. CONCLUSION: Children are generally accepting of upper partial dentures, but their poor clinical performance is of concern and there is need for improvement.

Adaptation, Psychological↗
PubMed1997

A new method for assessing masticatory performance: a feasibility and reproducibility study.

The aim of this study was to develop a method for assessing masticatory performance based on incorporation of a colour binder in a test material with the presumption that the absorption of the colour is proportional to the total surface area of the masticated material. This was tested in vitro with erythrosin as the colour substance and Praestol 655BC as the colour binder incorporated into Satou's synthetic test material (equal amount of carnauba wax and bariumsulphate). The authors found that the difference in spectrophotometrical absorbance between a standard erythrosin solution and the supernatant of the same solution incubated half an hour with artificially pulverized test material was almost linearly correlated (r = 0.997) with the particle surface. This test material was then fabricated as small tablets and four adults chewed repeatedly five grams of these tablets to assess selectivity and reproducibility of the method. A good selectivity was found in that within the total range of the difference in absorbance (0.47-1.19) an inter-individual difference of more than 0.17 is significant on a 95% level with double experiments. There were no differences in the intra-individual variation for double determinations between immediate repeat and 1 week interval performances but the reproducibility was disturbed when two subjects used their partial dentures.

Absorption↗
PubMed1997

The effect of chronic periodontal disease on human jaw muscles: a pilot study using computed tomography.

Patients with chronic periodontal disease sometimes complain of difficulty in masticating hard foods. Computed tomography (CT) was used to investigate the cross-sectional area (CSA) and density of the masseter and medial pterygoid muscles in a pilot study of 12 healthy female subjects aged 30-39 years. Six subjects (the 'diseased' group) had suffered from chronic periodontal disease and had, on average, 40% bone loss. Their disease had been treated by scaling and root planning and had remained clinically stable for at least 6 months before their inclusion in the study. The six age-matched 'control' subjects had no history of periodontal disease. All bone-loss measurements were evaluated as a percentage of root length. At defined scan planes, sections of both muscles were readily identified. Results from the 'diseased' group as compared with the 'control' group revealed that in the former the CSA of masseter and medial pterygoid was reduced significantly by 25% and 10%, respectively. There were no significant differences in the X-ray density of both muscles between the two groups, which indicated a similar fibro-fatty content. These findings indicate a reduction in the masticatory force that may be utilized by patients with reduced periodontal support and may help explain their masticatory difficulties.

Adult↗
PubMed1998

The masticatory-parotid salivary reflex in edentulous subjects.

The parotid-masticatory salivary reflex has been studied in edentulous subjects. Salivary flow was recorded by siting a modified Lashley cup over the orifice of the parotid duct on one side of the mouth. Subjects chewed on small pieces of silicone rubber with their complete dentures for 1 min periods which resulted in a reflex secretion of parotid saliva. The secretion was greatest when the subject chewed on the same side of the mouth (ipsilateral) as the salivary flow was recorded. Less salivary flow resulted when the subjects chewed on the opposite side of the mouth (contralateral). Anaesthesia of the mucosa of the maxillary and mandibular denture-bearing area was achieved by placing a thin layer of anaesthetic ointment in the fitting surface of the dentures on the side ipsilateral to the Lashley cup. This resulted in a reduction of salivary flow in response to similar chewing cycles. The results confirmed the presence of a parotid-masticatory salivary reflex in edentulous subjects which appears similar in many respects to that of dentate subjects. It is likely that receptors in the oral mucosa are stimulated when an edentulous subject masticates with complete dentures and that activity in these mechanoreceptive neurones results in the reflex salivary secretion.

Denture, Complete↗
PubMed1998

Denture mobility with six degrees of freedom during function.

The purpose of this study was (1) to assemble and verify a system to measure the three-dimensional (3-D) movement of the upper and lower complete dentures and the movement of the mandible simultaneously, and (2) to analyse the relation between denture movements and the path of closure of the mandible during function. A 3-D motion capture system with four infrared TV cameras was used for this purpose. The relation between the dentures and the mandibular movements was analysed through the change of the inner product of normal vectors of the denture occlusal planes and mandibular planes. The mandibular movements were classified into two types; the normal stroke (the path of closure was on the ipsilateral side of mastication) and the reverse stroke (on the contralateral side). The results showed that the system could measure the denture mobility within a 0.3 mm error. The mobility of the upper dentures had a correlation to the path of closure of the mandible regardless of the working side or nonworking side, and the lower dentures had a tendency to move toward the working side.

Aged↗