Factors Influencing Changes in Masticatory Performance as a Result of Wearing Removable Partial Dentures in Patients with Partially Edentulous Arches.

PURPOSE: To measure masticatory performance (MP) in partially edentulous patients when wearing removable partial dentures (RPDs) versus when not wearing RPDs, and to identify factors that could enable clinical evaluations related to differences in MP. MATERIALS AND METHODS: This study consisted of 87 partially edentulous patients (57 females, 30 males; mean age, 69.41 ± 8.85 years) categorized as Eichner classification B who habitually wore RPDs. MP was evaluated while wearing versus while not wearing RPDs using test gummy jellies. The participants were categorized into four groups by the presence of occlusal contacts in one to three of the molar and premolar regions (occlusal support), or in the anterior region only, according to the Eichner index (B1-B4). The participants were also categorized according to the jaw on which the RPDs were worn and the Kennedy classification, and evaluated in regard to changes in MP resulting from wearing RPDs. Additionally, the rate of change in MP (MP-rv) was calculated for each participant using MP when not wearing RPDs as a reference, and factors affecting MP-rv were evaluated using single or multiple regression analysis and the Kruskal-Wallis test with multiple comparisons. RESULTS: Significant increases in MP-rv were observed for all participants and for those with occlusal support in two (p = 0.006) and three regions (p = 0.019); however, no significant differences were observed when wearing and not wearing RPDs in participants with (p = 0.090) and those without occlusal support in one region (p = 0.474). With respect to the jaw on which the RPDs were worn, only maxillary or both maxillary/mandibular RPDs tended to have higher MP-rvs than did only mandibular jaws. The results of the multiple regression analysis showed that Kennedy Class I edentulous arches were a factor in increasing MP-rv (standard partial regression coefficient = 0.46, p < 0.05). CONCLUSION: According to the results of this study, among various factors on the degree of improvement in masticatory performance by wearing RPDs, bilateral missing posterior teeth might be a predictor for achieving clinical improvement.

Validity of a visual scoring method using gummy jelly for evaluating chewing efficiency in a large-scale epidemiological survey.

BACKGROUND: Several methods exist for objectively evaluating chewing efficiency by using gummy jelly. However, the validity of the subjective visual evaluation of chewing efficiency has not been assessed. OBJECTIVE: To verify with an epidemiological study, the validity of a visual scoring method using gummy jelly by testing the relationship between masticatory performance (MP) using a fully automatic measuring system and visual score (VS) using a visual scoring method. METHODS: Community-dwelling elderly individuals (n = 1234) ≥70 years old participated. One evaluator measured VS consecutively after participants chewed the gummy jelly (ie, actual-VS). The chewed jelly was photographed. Two evaluators used the photograph to measure the gummy jelly (ie, photo-VS). To test the validity of both methods, the correlation between actual-VS and MP and between photo-VS and MP were analysed. Inter-rater reliability between the evaluators of photo-VS was analysed. RESULTS: Significant correlations existed between actual-VS and MP and between photo-VS and MP (r = 0.86-0.87; P < 0.001). The intra-class correlation coefficient of the inter-rater reliability for photo-VS was very high (0.93; P < 0.001; 95% confidence interval: 0.877-0.953); however, the distribution of photo-VS deviated slightly from the actual-VS. A large coefficient of variation in the MP for low VSs suggested the influence of incomplete comminution, which was not reflected by the VS, and the accidental swallowing of small pieces during chewing. CONCLUSION: The VS deviated slightly from the MP calculated using a fully automated method; however, the VS can be utilised for epidemiological surveys with numerous participants.

The impact of a newly constructed removable denture on the objective and subjective masticatory function.

Purpose This study investigated the impact of the renewal of a removable prosthesis on the masticatory function by subjective and objective measures and its variation among the types of occlusal support.Methods Seventy-eight patients who received newly fabricated removable denture patients participated in this study. For the objective assessment, masticatory performance was measured using test gummy jelly. For the subjective assessment, standardized questionnaires about food acceptability and the oral health-related quality of life (OHRQoL) were used. Pre- and post-insertion assessments were performed for each subject. Subjects were divided into three groups according to their posterior occlusion: with posterior occlusion (w/PO), without posterior occlusion (w/o PO) and edentulous. Wilcoxon's signed rank test was used to compare the pre- and post-treatment measurements of each assessment. The analysis of covariance and a multiple comparison were used to assess the effect of new dentures and differences due to occlusal support.Results The masticatory performance, OHRQoL and food acceptability following prosthodontic treatment were significantly improved by new denture insertion. The masticatory performance among groups varied to a relative degree. The rate of masticatory performance improvement for edentulous subjects was twice that in w/PO subjects. The OHRQoL was significantly lower in the w/o PO and edentulous groups with old denture than patients w/PO. The food acceptability improved most markedly in the edentulous group.Conclusions The improvement in the masticatory performance by new denture insertion varied among types of occlusal support. Re-establishing the occlusal support of edentulous patients may help restore their OHRQoL and improve food acceptability.

[Successful pain control by continuous epidural infusion of ropivacaine for a pregnant woman with biliary colic].

This report describes a pregnant woman with common bile duct stones whose colic was successfully treated by prolonged continuous epidural infusion of ropivacaine. A 32-year-old woman in the 26th week pregnancy complained of severe abdominal pain due to common bile duct stones. We adopted ropivacaine for infusion into the epidural space using patient controlled analgesia system considering fetoplacental circulation. We administered the solution successfully for 3 weeks, but we observed that the effectiveness of ropivacaine became reduced. This suggests that tachyphilaxis to ropivacaine might have developed by its long-term infusion.

Onset of vecuronium-induced neuromuscular block after a long priming interval.

PURPOSE: We examined whether a new application of the priming principle, i.e., having the priming dose of vecuronium administered before the insertion of the epidural catheter, would hasten the onset of the neuromuscular block induced by the intubating dose of vecuronium. METHODS: Forty-five adult female patients scheduled for general anesthesia combined with epidural anesthesia were studied. In group A ( n = 15), the priming dose of vecuronium, 0.01 mg.kg(-1), was administered before insertion of the epidural catheter. The intubating dose of vecuronium, 0.09 mg.kg(-1), was given after the insertion of the epidural catheter. In group B ( n = 15), the priming dose of vecuronium, 0.01 mg.kg(-1), was given 4 min before the intubating dose of vecuronium, 0.09 mg.kg(-1). In the control group ( n = 15), no priming dose was given, and only the intubating dose of vecuronium, 0.10 mg.kg(-1), was administered. In all three groups, general anesthesia was induced with propofol 2.5 mg.kg(-1), and the trachea was intubated when T1/control value (control twitch height in response to train-of-four stimuli) was less than 0.1. RESULTS: In group A, the priming dose was given 16 +/- 3 min (mean +/- SD) before the administration of the intubating dose. The times to onset of neuromuscular block in groups A and B, and the control group were: 145 +/- 30, 184 +/- 45, and 219 +/- 23 s, respectively ( P < 0.05 among the three groups). In all three groups, intubating conditions (graded on a four-point scale) were excellent ( P = 0.59). Before the induction of anesthesia, symptoms of paralysis were observed in 5, 4, and 0 patients in groups A and B and the control group, respectively ( P < 0.05 between group A or B vs control group). CONCLUSIONS: If the priming dose of vecuronium is given after a long priming interval (16 +/- 3 min), the time to onset of the neuromuscular block caused by the intubating dose of vecuronium is markedly shorter than when the conventional priming interval of 4 min is employed.