Effect of Side Switch Frequency on Masticatory Mixing Ability and Perception of Taste, Muscular Fatigue and Saliva Production: A Randomized Crossover Trial.
Overview
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University of Barcelona
- Enrollment
- 36
- Locations
- 1
- Primary Endpoint
- Side-switch Index
Overview
Brief Summary
The main aim of this cross-over intervention study is to assess the effect of masticatory side-switch frequency on different aspects of masticatory function, including masticatory mixing ability and rhythm. A secondary aim is to explore the subjective perception of taste, muscular fatigue, and saliva production through a VAS. Thirty-six volunteers recruited for convenience, among students of the Degree of Dentistry of the Faculty of Medicine and Health Sciences of the University of Barcelona, will perform 6 tests, each consisting of 2 assays, chewing a two-coloured chewing gum, during 40 masticatory cycles. The tests will be randomised masticatory sequences of "free-style", "unilateral-right", "unilateral-left", switching the chewing side at 5% "G05", at 15% "G15" and at 25% "G25". Video recordings of these tests will be made to later assess, on slow playback, the change of the chewing side and the masticatory rhythm. The masticatory mixing ability will be determined through the scanning and posterior analysis of the red-channel in the histogram plug-in in "ImageJ" (R).
Detailed Description
This this cross-over intervention study aims to assess the effect of masticatory side-switch frequency on different objective aspects of masticatory function, including masticatory mixing ability and rhythm, as well as the subjective perception of taste, muscular fatigue, and saliva production through a VAS. Each of the thirty-six volunteers recruited for convenience, among students of the Degree of Dentistry of the Faculty of Medicine and Health Sciences of the University of Barcelona, will perform 6 tests, each consisting of 2 assays, chewing a two-coloured chewing gum, during 40 masticatory cycles. One test involves freestyle mastication in which the participant will be asked to masticate the chewing gum. Two tests involve chewing the gum unilaterally (i.e., only on the right-hand side, and only on the left) varying the order of these assays. In the last three tests, the volunteer will switch chewing side in 5% (G05), 15% (G15), or 25% (G25) respectively; the sequence of the assays will be randomized. Twenty-four of these volunteers will be randomly selected to repeat these tests after a period of two weeks. The masticatory mixing ability will be determined through the "mixing capacity index" (MCI), obtained from through the scanning and posterior analysis of the red-channel in the histogram plug-in in "ImageJ" (R), and the masticatory rhythm will be assessed through the masticatory frequency as the ratio of masticatory cycle number to masticatory time. The control variables will include age and sex.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Basic Science
- Masking
- None
Eligibility Criteria
- Ages
- 18 Years to 75 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Older than 18 years old.
- •Natural dentition (minimum 24 teeth)
Exclusion Criteria
- •Active orthodontics treatment.
- •Intraoral pain.
- •Temporomandibular joint pain.
- •Masticatory muscle pain.
- •Large dental restorations.
- •Dental prosthesis.
- •Edentulous spaces.
Outcomes
Primary Outcomes
Side-switch Index
Time Frame: 1 hour
The number of side switches during the 40 masticatory cycles for each assay will be determined using slow playback of the video recordings of the freestyle mastication test. In the case that this switch is a change of side from left to right or right to left, we will assign a value of "1". If this switch consists of a change from the right or left to central or vice versa, we will assign a value of "0.5". If there is no change of side, the value assigned to this chewing cycle will be "0". To determine the Side-switch Index, the number of side changes will be divided by the maximum number of changes possible during these 5 assays (78).
Masticatory mixing ability
Time Frame: 1 hour
Masticatory mixing ability will be calculated from the mixing capacity for each type of test (free, right, left and guided). Chewing gum will flattened between two rigid surfaces to a thickness of 1.5 mm. The two sides of the chewing gum will then be scanned at a resolution of 300 dpi. The images will be processed with "ImageJ" with the "Color-Histogram" plugin. Before mixing, the green and red color of the chewing gum are represented in the histogram of the red channel as two separate peaks: one in low intensity and one in high intensity, representing the green and red color of chewing gum, respectively. After mixing, the colors are mixed and so the two peaks merge into one peak. The standard deviation of the intensity distribution is taken as a measure of the mixture of the two colors in the chewing gum. The standard deviation at an early stage of mixing is relatively high, and decreases as the colors are mixed; thus, a high value of the mixing index means a high mixing capacity.
Secondary Outcomes
- Degree of taste perception during this masticatory assay(1 hour)
- Masticatory Frequency(1 hour)
- Degree of muscular fatigue during this masticatory assay(1 hour)
- Degree of salivary secretion during this masticatory assay(1 hour)
Investigators
Jordi Martinez-Gomis
Associate Professor DDS. PhD
University of Barcelona