Conventional Versus Implant-Retained Overlay Dentures: A Pilot Study of Masseter and Anterior Temporalis Electromyography
Implant-supported overlay dentures (ISODs) have been widely accepted among patients using conventional removable complete dentures (CRCDs). The present study aimed to comparatively study conventional and ISODs in terms of function and coordination of masticatory muscles using electromyograms. Included were 10 patients with ISODs (each with 2 implants in the intercanine area). The mean wave range (MWR) and frequency (MWF) of masseter and temporalis were recorded with (ISOD) and without (CRCD) ball attachments while maximum clenching on cotton rolls (cotton roll clenching), maximum intercuspal clenching (clenching), and unilateral gum chewing (chewing) using electromyography. Data were analyzed in SPAW using t-paired for matched groups and independent-sample t tests for unmatched ones. The MWF differences were not statistically significant with or without attachments (P > .05). Without attachments in place, the MWF of both masseter and temporalis muscles significantly decreased when patients clenched on cotton rolls (P = .01 and .02, respectively) and when chewing unilaterally (both P = .01). With attachments present, the right and left temporalis muscles did not show identical mean wave ranges while chewing (P = .01). Without attachments, this disharmony was seen in the left and right masseter muscles (P = .03). The MWR of masseter was higher in men while chewing with attachments (P = .02). Without attachments, the MWR of temporalis was higher in women while cotton roll clenching (P = .03) and chewing (P = .02). These findings are seemingly in favor of improved masticatory function and coordination in edentulous patients with the application of ISODs.
Figure 1. Comparative illustration of the mean wave range values of the masseter muscle during 3 masticatory functions, namely, clenching on cotton roll, clenching in maximum intercuspation, and gum chewing with and without attachments under the mandibular implant-supported overlay dentures. Statistically significant difference was found only in cotton roll clenching. Figure 2. Comparative illustration of the mean wave range values of the temporalis muscle in 3 masticatory functions, namely, clenching on cotton roll, clenching in maximum intercuspation, and gum chewing with and without attachments under the mandibular implant-supported overlay dentures. Statistically significant difference was found only in cotton roll clenching. Figure 3. Comparative illustration of the mean wave range values of the right and left masseter muscles during 3 masticatory functions, namely, clenching on cotton roll, clenching in maximum intercuspation, and gum chewing without the attachments of the mandibular implant-retained overlay dentures in place. During chewing, right masseter muscles were associated with significantly higher ranges compared with those of the left. Figure 4. Comparative illustration of the mean wave range values of the right and left temporalis muscles during 3 masticatory functions, namely, clenching on cotton roll, clenching in maximum intercuspation, and gum chewing with attachments of the mandibular implant-retained overlay dentures in place. During chewing, right temporalis muscles were associated with significantly higher ranges compared with those of the left. Figure 5. Comparative illustration of the mean wave range values of the masseter muscles of men and women during 3 masticatory functions, namely, clenching on cotton roll, clenching in maximum intercuspation, and gum chewing with the attachments of the mandibular implant-retained overlay dentures in place. Men showed significantly higher values than women while clenching. Figure 6. Comparative illustration of the mean wave range values of the temporalis muscles during 3 masticatory functions, namely, clenching on cotton roll, clenching in maximum intercuspation, and gum chewing without the attachments of the mandibular implant-retained overlay dentures in place. Women showed significantly higher values than men while clenching on cotton roll and gum chewing. Figure 7. Comparative illustration of the mean wave frequency values of the masseter muscle in 3 masticatory functions, namely, clenching on cotton roll, clenching in maximum intercuspation, and gum chewing with and without attachments under the mandibular implant-supported overlay dentures. Statistically significant differences were found in cotton roll clenching and chewing. Figure 8. Comparative illustration of the mean wave frequency values of the temporalis muscle in 3 masticatory functions, namely, clenching on cotton roll, clenching in maximum intercuspation, and gum chewing with and without attachments under the mandibular implant-supported overlay dentures. Statistically significant differences were found in cotton roll clenching and chewing.
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