title: The 6-min mastication test: a unique test to assess endurance of continuous chewing, normal values, reliability, reproducibility and usability in patients with mitochondrial disease.
abstract: In patients with mitochondrial disease, fatigue and muscle problems are the most common complaints. They also experience these complaints during mastication. To measure endurance of continuous mastication in patients with mitochondrial diseases, the 6-min mastication test (6MMT) was developed. This study included the collection of normal data for the 6MMT in a healthy population (children and adults). During 6 min of continuous mastication on a chew tube chewing cycles per minute, total amount of chewing cycles and the difference between minute 1 (M1) and minute 6 (M2) were collected in 271 healthy participants (5-80 years old). These results were compared with those of nine paediatric and 25 adult patients with a mitochondrial disease. Visual analogue scale (VAS) scores were collected directly after the test and after 5 min. A qualitative rating was made on masticatory movements. The reproducibility of the 6MMT in the healthy population with an interval of approximately 2 weeks was good. The inter-rater reliability for the observations was excellent. The patient group demonstrated lower total amount of chewing cycles or had greater differences between M1and M6. The 6MMT is a reliable and objective test to assess endurance of continuous chewing. It demonstrates the ability of healthy children and adults to chew during 6 min with a highly stable frequency of mastication movements. The test may give an explanation for the masticatory problems in patient groups, who are complaining of pain and fatigue during mastication.
authors.affiliation: Donders Centre for Neuroscience, Department of Rehabilitation, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: L
authors.identifier: http://orcid.org/0000-0002-6501-0061
authors.initials: L
authors.lastname: van den Engel-Hoek
authors.affiliation: Donders Centre for Neuroscience, Department of Rehabilitation, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Knuijt
authors.affiliation: Donders Centre for Neuroscience, Department of Rehabilitation, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: M H J C
authors.initials: MH
authors.lastname: van Gerven
authors.affiliation: Donders Centre for Neuroscience, Department of Rehabilitation, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: M L J
authors.initials: ML
authors.lastname: Lagarde
authors.affiliation: Donders Centre for Neuroscience, Department of Rehabilitation, Radboud University Medical Center, Nijmegen, The Netherlands.|Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands.
authors.forename: J T
authors.initials: JT
authors.lastname: Groothuis
authors.affiliation: Donders Centre for Neuroscience, Department of Rehabilitation, Radboud University Medical Center, Nijmegen, The Netherlands.|Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands.
authors.forename: I J M
authors.initials: IJ
authors.lastname: de Groot
authors.affiliation: Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands.|Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: M C H
authors.initials: MC
authors.lastname: Janssen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001732:Bite Force; D002638:Chewing Gum; D002648:Child; D002675:Child, Preschool; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008409:Mastication / Q000502:physiology*; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000503:physiopathology*; D009068:Movement; D018763:Muscle Fatigue / Q000502:physiology*; D009426:Netherlands; D010807:Physical Endurance / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D002638:Chewing Gum
keywords: mastication; mitochondrial diseases; oral rehabilitation; physical endurance