Influence of removable prostheses on mastication in elderly subjects with rheumatoid arthritis.

Rheumatoid arthritis (RA) is a prevalent disease in the elderly population, and it may affect the temporomandibular joint (TMJ) and the stomatognathic system. This study evaluated masticatory function in elderly patients with RA before and after oral rehabilitation with removable prostheses. Forty-five elders with partial or total edentulism who were using unsatisfactory removable prostheses were selected and assigned to 3 groups: RA with TMJ involvement, RA without TMJ involvement and healthy controls. Masticatory function was assessed in terms of masticatory performance (MP) and maximum bite force (MBF). The former was determined by the sieving method, and the latter was measured by pressure sensors placed in the bilateral molar regions. The variables were first evaluated in elderly subjects wearing unsatisfactory prostheses and re-assessed after participants had received new removable prostheses. Comparisons between groups and among time points were performed with analysis of variance for repeated measures and the Tukey-Kramer test (P < .05). Comparison among groups showed decreased MP in elders with RA before new prosthesis insertion (P < .05). Irrespective of TMJ involvement, MP improved after treatment in subjects with RA. Rheumatoid arthritis groups also showed decreased MBF (P < .05), which improved after new prosthesis insertion. Rheumatoid arthritis might impair masticatory function, and well-fitted removable prosthesis insertion might be very beneficial in elders with RA.

Mandibular movements and bite force in Alzheimer's disease before and after new denture insertion.

Chewing impairment has been observed in elders with Alzheimer's disease (AD); however, it is unknown whether oral rehabilitation can improve their masticatory function. This study evaluated the influence of new removable prostheses on chewing function of patients with AD. Participants using removable dentures were divided into two groups: patients with mild AD (77·2 ± 5·8 years, n = 16) and controls (76·0 ± 4·4, n = 16). All participants received general dental treatment and new total and/or partial removable prostheses. After 2 months of adaptation to the new dentures, chewing was evaluated by the following parameters: masticatory cycle time (CT), cycle velocity (CV), and opening (OA) and closing mandibular angles (CA), registered by a kinesiographic device. Maximum bite force (MBF) was assessed using a strain sensor. Evaluations were performed at baseline and after insertion of the new prostheses. A mixed model (α = 5%) was used for within- and between-subject analyses. After insertion of new prostheses, CT was reduced, and CV and MBF were increased in both groups (P < 0·05). There were no changes in OA or CA (P > 0·05). Compared to controls, elders with AD showed higher CT and reduced MBF and CV both at baseline and after insertion of new prostheses (P < 0·05). However, OA and CA did not differ between groups (P > 0·05). Insertion of new removable prostheses improved masticatory function in elders with and without AD, but patients with mild AD still had reduced chewing parameters compared to controls.

Oral physiology, nutrition and quality of life in diabetic patients associated or not with hypertension and beta-blockers therapy.

The relationship between type 2 diabetes oral physiology, nutritional intake and quality of life has not been fully elucidated. We assessed the impact of type 2 diabetes - exclusive or associated with hypertension with beta-blockers treatment - on oral physiology, mastication, nutrition and quality of life. This cross-sectional study was performed with 78 complete dentate subjects (15 natural teeth and six masticatory units minimum; without removable or fixed prostheses), divided into three groups: diabetics (DM) (n = 20; 45·4 ± 9·5 years), diabetics with hypertension and receiving beta-blockers treatment (DMH) (n = 19; 41·1 ± 5·1 years) and controls (n = 39; 44·5 ± 11·7 years) matched for gender, age and socioeconomic status. Blood glucose, masticatory performance, swallowing threshold, taste, food intake, stimulated and unstimulated salivary flow, pH and buffering capacity of saliva were assessed. Glycemia was higher in DM than in controls (P < 0·01). No differences were observed between DM and controls for nutrition and quality of life. Both stimulated and unstimulated salivary flow rate were lower in DMH (P < 0·01), which also presented the lowest number of teeth and masticatory units (P < 0·0001), and reduction in the number of chewing cycles (P < 0·01). Controls showed lower Decayed Missing Filled Teeth index (DMFT) scores in comparison with DMH (P = 0·021). Masticatory performance and saliva buffering capacity were similar among groups. Exclusive type 2 diabetes did not alter oral physiology, nutrition or quality of life. However, when hypertension and beta-blockers treatment were associated with diabetes, the salivary flow rate, chewing cycles and number of teeth decreased.

Mastication and jaw motion of partially edentulous patients are affected by different implant-based prostheses.

The main goal of prosthetic treatment is to restore masticatory function. However, insufficient evidence supports the recommendation of one specific prosthetic intervention for partially edentulous patients. Function after the use of three different prostheses by the same partially edentulous subject. Mastication was assessed in 12 subjects (mean age 62.6 ± 7.8 years) after they had used removable partial dentures (RPDs), implant-supported partial dentures (IRPDs) and implant-fixed partial dentures (IFPDs). Masticatory ability (MA) was estimated by visual analogue scale questionnaire, while the mandibular chewing motion was evaluated by kinesiographic device, representing an objective measurement of masticatory function. Data were analysed by repeated-measures anova followed by Tukey-Kramer (P < 0.05). MA improved after IRPD and IFPD use (P < 0.05). Opening, closing and total cycle time duration were reduced after both IRPD and IFPD use (P < 0.05), irrespectively the implant prosthesis type. IFPDs and IRPDs restore the masticatory function of partially edentulous patients better than RPDs.

Effect of complete and partial removable dentures on chewing movements.

Partial or complete edentulism impairs mastication. However, it is unclear how the chewing cycle is affected by prosthetics. We evaluated the chewing movements of patients fitted with complete (CD) or removable partial denture (RPD). A total of 29 subjects were kinesiographically evaluated during chewing of peanuts and Optocal portions in a random sequence. The subjects were divided into two groups according to prosthesis type. Group RPD was composed of 14 partially edentulous patients using a lower distal extension RPD (mean age 61 ± 8 years), and group CD contained 15 completely edentulous patients using CD (mean age 65·9 ± 7·9 years) in both jaws. Opening, closing, occlusal and masticatory cycle times, movement angle (opening and closing), maximum velocity (opening and closing), total area and chewing cycle amplitudes were evaluated. The results were subjected to anova and Tukey's HSD test at a significance level of 5%. The RPD group exhibited shorter opening and closing phases and masticatory cycle time (P < 0·05). Maximum velocities were also higher in the RPD group, irrespective of the test material (P < 0·05). The area and amplitude of the chewing envelope was smaller in the CD group (P < 0·0001). The test material did not influence chewing cycles in any of the parameters evaluated (P > 0·05). RPD wearers use a faster chewing sequence with greater vertical and lateral jaw excursions compared with CD wearers.

Effect of incisal tooth wear and restoration on interocclusal distance during Brazilian Portuguese language speech.

AIM: The aim of this study was to investigate changes in interocclusal distance (IOD) during pronunciation of /m/ and /s/ sounds in Brazilian Portuguese, in patients presenting dental wear due to bruxism, before and after placement of a stabilization appliance and restorative treatment. METHODS: Subjects were divided into a control group of 19 patients with no dental wear and an experimental group of 18 patients presenting dental wear on anterior teeth due to bruxism. A stabilization appliance was placed in each patient in the experimental group and anterior teeth were restored. A magnetic jaw-tracking device measured the interocclusal distance during pronunciation of /m/ and /s/ phonemes. Interocclusal distance for the experimental group was evaluated one week before and again immediately before the appliance was inserted and 24 hours, 7 days, 1 month and 2 months after appliance insertion. The same evaluation was performed 7 days and 1 month after restorative treatment. In the control group, the measurements were carried out at the same intervals. RESULTS: Comparison between groups revealed a significant difference (P<0.05) in interocclusal distance for the /m/ sound at all evaluation intervals. No differences were found before and after appliance insertion and restorative treatment with either phoneme. CONCLUSION: Stabilization appliance therapy and restorative treatment of subjects with dental wear did not change the interocclusal distance during speech of /m/ and /s/ sounds in the Brazilian Portuguese language, however, when compared with normal subjects, the IOD values were higher for the dental wear group during pronunciation of the /m/ sound.

Mastication improvement after partial implant-supported prosthesis use.

Partially edentulous patients may be rehabilitated by the placement of removable dental prostheses, implant-supported removable dental prostheses, or partial implant fixed dental prostheses. However, it is unclear the impact of each prosthesis type over the masticatory aspects, which represents the objective of this paired clinical trial. Twelve patients sequentially received and used each of these 3 prosthesis types for 2 months, after which maximum bite force was assessed by a strain sensor and food comminution index was determined with the sieving method. Masseter and temporal muscle thicknesses during rest and maximal clenching were also evaluated by ultrasonography. Each maxillary arch received a new complete denture that was used throughout the study. Data were analyzed by analysis of variance for repeated measures, followed by the Tukey test (p < .05). Maximum bite force and food comminution index increased (p < .0001) after implant-supported dental prosthesis and implant fixed dental prosthesis use, with the higher improvement found after the latter's use. Regardless of implant-retained prosthesis type, masseter muscle thickness during maximal clenching also increased (p < .05) after implant insertion. Partial implant-supported prostheses significantly improved masseter muscle thickness and mastication, and the magnitude of this effect was related to prosthesis type.