Jocelyne S. Feine

A Psychophysical Comparison of Sensory and Affective Responses to Four Modalities of Experimental Pain

It is generally accepted that the sensory and affective components of pain may be differentially associated with various acute and chronic diseases, and that some treatment regimens are best directed toward certain aspects of the pain experience. In addition, experimental animal models have been described that presume to assess either the sensory-discriminative aspects of phasic pain or the affective responses associated with tonic pain. The present psychophysical experiment directly compares the perceived intensity and unpleasantness of sensations evoked by four types of experimental noxious stimuli: contact heat, electric shock, ischemic exercise, and cold-pressor pain. A novel pain measurement technique is described that incorporates unbounded magnitude-estimation/category scales; this technique allows precise ratio responses, while minimizing within- and between-subject variability. We observe that, relative to the perceived intensity of the individual stimuli, subjects consistently differentiate among the degrees of unpleasantness evoked by the four stimulus modalities. Ischemic exercise and cold-pressor pain evoke higher estimates of unpleasantness, and thus may better mimic the pain of chronic disease. The relative unpleasantness produced by contact heat is significantly less than that of the other modalities tested, and therefore contact heat stimuli may be ideally suited for assessing sensory-discriminative aspects of pain perception. Possible neurophysiological mechanisms underlying the observed differences in perceived unpleasantness are discussed in relation to the growing body of literature concerning tonic and phasic pain stimuli.

Sex differences in the perception of noxious heat stimuli

&NA; This study compared pain perception in young male and female subjects, using experimental noxious heat stimuli. During 2 sessions, each of 40 subjects rated the magnitude of 120 heat stimuli, ranging from 45°C to 50°C. The study included a comparison of visual analogue and magnitude matching rating procedures, as well as a test of simulated analgesia, in which the range of stimuli presented during the 2 experimental sessions was shifted by 1°C. We found that females rated noxious heat stimuli as more intense than did males, independent of the gender of the experimenter or the type of rating scale. In addition, the data suggest that females discriminate among the painful heat intensities better than males. For example, female subjects showed significant between‐session discrimination of noxious heat stimuli, while male subjects did not, and females produced steeper within‐session stimulus‐response functions than did males. These observed differences in nociceptive discrimination between males and females indicate that the sex‐related variation in pain perception is probably related to sensory factors rather than differences in attitude or emotional response.

Measuring the Effect of Intra-oral Implant Rehabilitation on Health-related Quality of Life in a Randomized Controlled Clinical Trial

The importance of assessing the impact of treatments for chronic conditions on an individuals quality of life has been well-established. In this randomized clinical trial, oral-health-rclated quality of life, measured with the Oral Health Impact Profile (OHIP), was compared between two groups of edentulous patients. One group (n = 54) received mandibular implant-supported overdentures, and the other group (n = 48) received conventional dentures. Assessments were performed pre-treatment and two months after the prostheses were delivered. The multivariate model showed that implant treatment was significantly associated with lower post-treatment OHIP scores (p = 0.0002), indicating a better quality of life. In addition, pre-treatment OHIP scores, treatment allocation, age, sex, and marital status explained 31% of the variation in post-treatment OHIP scores (F = 0.0001). These results suggest that implant treatment provides significant short-term improvement over conventional treatment in oral-health-related quality of life.

An assessment of the efficacy of physical therapy and physical modalities for the control of chronic musculoskeletal pain

Abstract An analysis of review articles and controlled clinical trials for temporomandibular disorders and similar chronic musculoskeletal pain disorders was carried out. Although little evidence was found that any specific therapy had long‐term efficacy greater than placebo, we did find strong evidence that symptoms improve during treatment with ost forms of physical therapy, including placebo. When the frequency of significant between‐group differences in trials that used placebo and waiting list control (i.e., no treatment) groups were compared, it was found that treatment was better than placebo in only 7/22 trials, whereas treatment was almost always better than no treatment (15/16). This difference was highly significant (P=0.001). A similar analysis of trials that included more than one treatment group showed that while equal amounts of treatment were usually associated with equal outcome (9/10), unequal treatment regimes led to unequal outcome (10/15; P=0.012). The group that received the most therapy appeared to do best. In conclusion, it seems that patients are helped during the period that they are being treated with most forms of physical therapy. However, most of these therapies have not been shown to be more efficacious than placebo.

Impact of implant support for mandibular dentures on satisfaction, oral and general health‐related quality of life: a meta‐analysis of randomized‐controlled trials

OBJECTIVES The aim of this study was to examine systematically the data published on the efficacy of mandibular implant-retained overdentures from the patients perspective. MATERIAL AND METHODS Medline, Embase, The Cochrane Central Register of Controlled Trials and The Cochrane Systematic Reviews Database were searched and complemented by hand searching. All randomized-controlled trials published in English or French up to April 2007 were included, in which conventional dentures and mandibular implant overdentures in adult edentulous individuals were compared. The outcomes of interest were patient satisfaction, oral and general health-related quality of life. Random effects models were used to pool the effect sizes (ES) of all included studies. RESULTS Ten publications of seven randomized-controlled trials were identified and eight were included in the meta-analysis. When compared with mandibular conventional dentures, implant overdentures were rated to be more satisfactory at a clinically relevant level [pooled ES 0.80, z=3.56, 95% confidence intervals (CI) 0.36-1.24, P=0.0004], but a statistical heterogeneity was found (chi(2)=31.63, df=5, P<0.00001, I(2)=84%). The pooled ES for oral health quality of life was -0.41 (z=1.31, 95% CI, -1.02 to 0.20; P=0.19, chi(2)=11.53, df=2, P<0.003, I(2)=83%). There was a lack of evidence to show the impact of mandibular implant overdenture on perceived general health. CONCLUSIONS Our findings suggest that, although mandibular implant-retained overdentures may be more satisfying for edentulous patients than new conventional dentures, the magnitude of the effect is still uncertain. There is a need for additional evidence including cost-effectiveness analyses on the impact of mandibular implant overdentures and conventional dentures.

Within-subject Comparisons of Implant-supported Mandibular Prostheses: Choice of Prosthesis

Although previous studies have demonstrated that implant-supported prostheses are more satisfactory and efficient for edentulous patients than are conventional prostheses, until now no investigation has directly compared different types of implant-supported prostheses. We carried out a within-subject cross-over clinical trial with fixed and long-bar removable implant-supported mandibular prostheses. Fifteen subjects were randomly divided into two groups. One group received the fixed prosthesis first, while the other first received the removable. After a two-month adaptation period, psychometric measurements of various aspects of the prostheses and physiological tests of masticatory efficiency were carried out. The prostheses were then changed, and the procedures repeated. At the end of the study, subjects chose the prosthesis they wished to keep. In this paper, we report on the data gathered at this last appointment. Eight subjects chose the fixed (F group), and seven chose the removable (R group). Both groups rated stability and ability to chew with the fixed as significantly better than with the removable. However, the R group rated ease of cleaning as the most important factor governing their decision, followed by esthetics and stability. The F group considered stability to be the most important factor in their decision, followed by chewing ability and ability to clean. There was a tendency for the removable to be chosen by older subjects (+50 years). These results suggest that patients choose fixed or removable implant-supported prostheses for specific reasons, and that patient attitudes should be considered when the design of a prosthesis is being planned for an individual patient.

The Effects of Mandibular Two-implant Overdentures on Nutrition in Elderly Edentulous Individuals

It is unclear whether mandibular implant overdentures improve the nutritional state of edentulous patients better than conventional dentures. In a randomized clinical trial, we tested for post-treatment differences in nutritional status between patients with mandibular two-implant retained overdentures and those with conventional complete dentures. Edentulous subjects (ages 65–75 yrs) received two-implant mandibular overdentures (IOD, n = 30) or conventional dentures (CD, n = 30). Measures of nutritional state were gathered before and 6 mos after treatment. Significant improvements in anthropometric parameters were detected in the IOD but not in the CD group, for percent body fat (p = 0.011) and skin-fold thickness at the biceps, subscapularis, and abdomen (p < 0.05), with significant decreases in waist circumference (p < 0.0001) and waist-hip ratio (p = 0.001). Significant increases were seen in concentrations of serum albumin (p = 0.015), hemoglobin (p = 0.01), and B12 (p = 0.01). No significant between-group differences were found. These results suggest that low-cost IOD treatment may improve the nutritional state of edentulous people.

Sex differences in pain perception and anxiety. A psychophysical study with topical capsaicin

&NA; Much evidence indicates that women experience painful stimuli as more intense than men do. Nevertheless, some data suggest that sustained low‐level pain may be more disturbing to men than to women. The current experiment evaluated the hypothesis that pain is more disturbing for men than for women by comparing across genders sensory and emotional aspects of pain evoked by capsaicin. Ten men and 10 women (aged 20–46 years) received topical capsaicin for 30 min on the face in one session and on the ankle in another. The subjects rated on visual analog scales pain intensity, unpleasantness and anxiety each minute during capsaicin application and for 30 min after its removal. During capsaicin application, females rated both pain intensity (P=0.04) and unpleasantness (P=0.05) higher than did males. Further, subjects rated pain intensity and unpleasantness higher on the face than on the ankle, although the physical stimulus was the same. Despite their lower pain ratings, men reported more pain‐related anxiety than women (P=0.02). Moreover, men showed a significant positive correlation between anxiety and pain intensity and unpleasantness, whereas women did not. After removing the capsaicin, there was no overall effect of sex on either intensity (P=0.18) or unpleasantness (P=0.37) of the residual sensation. However, men still showed a positive correlation between anxiety and the intensity and unpleasantness of the sensation. Our data confirm with the topical capsaicin model that women rate pain higher than men, but despite their lower pain ratings, males have more anxiety related to pain.

Cost-effectiveness of Mandibular Two-implant Overdentures and Conventional Dentures in the Edentulous Elderly

Implementation of new therapies is usually governed by financial considerations, so efficacy studies should also include cost comparisons. The cost and effectiveness of mandibular conventional dentures (CD, n = 30) and two-implant overdentures (IOD, n = 30) were compared in elderly subjects. Effectiveness (Oral Health Impact Profile, OHIP-20) and cost were measured up to one year post-treatment. Data for subsequent years were estimated by the Delphi method. Using an average life expectancy of 17.9 years, the equalized annual costs (in Canadian dollars) were

Pain expression and stimulus localisation in individuals with Down's syndrome

399 for CD and