Cognitive Changes and Neural Correlates After Rehabilitation of Masticatory Function in Elderly -an Intervention Study

NCT04458207 | Active Not Recruiting

• 1 other identifier: Tugg&Tänk
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 2

Brief Summary

Today in elderly tooth loss and loss of oral function is widespread, but it is an underexplored modifiable risk factor potentially contributing to the development of dementia. In this interventional study a "cause-effect" relationship between mastication and cognition in humans will be investigated. A total of eighty (80) participants, 65-80 years of age, indicated for prosthodontic rehabilitation will be randomly assigned to either the experimental or the control group. Participants will be randomized into two different groups, measurements are going to be conducted before and after prosthetic rehabilitation. The difference between the two groups is that the control group are going to do two measurements before undergoing the rehabilitation, this to control for the test-re-test effect. The aim with this study is to determine if the rehabilitation of chewing function will cause changes in the neurocognitive assessments of episodic memory and learning.

Conditions

Chewing Problem; Cognitive Decline; Magnetic Resonance Imaging; Degenerative; Dementia; Mastication Disorder; Neurocognitive Dysfunction

Keywords

Magnetic resonance imaging; Chewing efficiency; Cognitive impairment; Masticatory dysfunction; Prosthetic rehabilitation

Outcome Measures

Primary Outcomes (1)

• Change in Brief Visuospatial Memory Test Revised (BVMT-R)

  Measuring non-verbal episodic memory. Measured in correct answers. Score: 0-36. A high score indicates a better performance.

  1: Baseline pre-test. 2: Change pre-test/post-test1, CG 3months after baseline, EG 3months after intervention (Int). 3: Change post-test1/post-test2, CG 3months after Int, EG 1year after Int. 4: Change post-test1/post-test2, CG 1year after Int.

Secondary Outcomes (13)

• Change in Rey Auditory Verbal Learning Test (RAVLT).

  1: Baseline pre-test. 2: Change pre-test/post-test1, CG 3months after baseline, EG 3months after intervention (Int). 3: Change post-test1/post-test2, CG 3months after Int, EG 1year after Int. 4: Change post-test1/post-test2, CG 1year after Int.

• Change in Trail Making Test from Delis Kaplan Executive Function System (D-KEFS)

  1: Baseline pre-test. 2: Change pre-test/post-test1, CG 3months after baseline, EG 3months after intervention (Int). 3: Change post-test1/post-test2, CG 3months after Int, EG 1year after Int. 4: Change post-test1/post-test2, CG 1year after Int.

• Change in Digit-Span from Wechsler Adult Intelligence Scale (WAIS):IV

  1: Baseline pre-test. 2: Change pre-test/post-test1, CG 3months after baseline, EG 3months after intervention (Int). 3: Change post-test1/post-test2, CG 3months after Int, EG 1year after Int. 4: Change post-test1/post-test2, CG 1year after Int.

• Change in Digit-symbol from Wechsler Adult Intelligence Scale (WAIS):IV

  1: Baseline pre-test. 2: Change pre-test/post-test1, CG 3months after baseline, EG 3months after intervention (Int). 3: Change post-test1/post-test2, CG 3months after Int, EG 1year after Int. 4: Change post-test1/post-test2, CG 1year after Int.

• Change in Color-Word Interference Test from Delis Kaplan Executive Function System (D-KEFS word)

  1: Baseline pre-test. 2: Change pre-test/post-test1, CG 3months after baseline, EG 3months after intervention (Int). 3: Change post-test1/post-test2, CG 3months after Int, EG 1year after Int. 4: Change post-test1/post-test2, CG 1year after Int.

Study Arms (2)

Experimental group (EG), the immediate rehabilitation group

EXPERIMENTAL

The experimental group will begin with the rehabilitation immediately after the first measurement of cognitive tests (pre-test). Three months after complete rehabilitation the first post-test (post-test 1) will be conducted on all participants. Participants will be recalled after about a year for a long-term follow up (post-test 2). The OHIP-14, chewing function test, saliva samples, neuropsychological assessments together with MRI assessments will also be recorded at different time points (i.e., pre-test, post-test 1 and post-test 2).

Procedure: Oral prosthetic rehabilitation

Control group (CG), the test-retest group

ACTIVE COMPARATOR

The control group will be tested with the cognitive tests two times (pre-test + post-test 1) at an interval of about three months or more inbetween tests and before the onset of the prosthodontic rehabilitation. Three months after complete rehabilitation the post-test (post-test 2) will be conducted on all participants. Further, participants will be recalled after about a year for a long-term follow up (post-test 3). The OHIP-14, chewing function test, saliva samples, neuropsychological assessments together with MRI assessments will also be recorded at these time points (i.e., pre-test, post-test 1, post-test 2 and post-test 3).

Procedure: Oral prosthetic rehabilitation

Interventions

Oral prosthetic rehabilitation PROCEDURE

Individual treatment options will be discussed with the participants individually and rehabilitation will be provided as agreed by the dentist and the participant. The rehabilitation will include fixed prosthodontics. The procedures will involve a control phase involving scaling, root planing oral hygiene instructions etc., extractions and bone augmentation when needed and temporary removable dentures. Restoration of the lost vertical dimension (if needed) with occlusal splints, tooth preparations, placement of dental implants (if needed) and finally cementation of dental crowns. The rehabilitation phase is estimated to take approximately 3-18 months, or more.

Control group (CG), the test-retest group; Experimental group (EG), the immediate rehabilitation group

Eligibility Criteria

• Age: 65 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Older Adult (65+)

You may qualify if:

• years of age at start
• Impaired chewing ability (Eichner index B2-B4, C1-C4)
• Dental rehabilitation with fixed prosthodontics, implant and/or tooth supported (overdentures included) \>10 occluding units
• Mini Mental State Examination (MMSE) score \>25

You may not qualify if:

• Brain trauma or stroke \<6 months
• Neurological disease (stroke, dementia, Alzheimer disease, Parkinson disease).
• Intellectual disability
• Psychological disorders
• Participants with chronic pain, depression or sleeping disorders
• Daily analgesic medication that may affect cognitive and/or executive performance of the brain
• Poor Swedish language skills, reading disabilities
• Severely reduced hearing or vision
• Prosthetic treatment with removable dentures (full or partial)
• Claustrophobia
• Difficulties in lying down in a supine position for about an hour, or any other difficulties related to the MRI head coil
• Participants with metal or medical implants in the body contraindicating MRI scan

Sponsors & Collaborators

• Folktandvården Stockholms län AB: lead
• Karolinska Institutet: collaborator
• Eastmaninstitutet: collaborator

Study Sites (2)

Eastmaninstitutet Folktandvården Stockholm AB

Stockholm, Stockholm County, 11324, Sweden

Location

Eastmaninsitutet, Department of Prosthodontics

Stockholm, 11324, Sweden

Location

Related Publications (9)

• O'Brien JT, Erkinjuntti T, Reisberg B, Roman G, Sawada T, Pantoni L, Bowler JV, Ballard C, DeCarli C, Gorelick PB, Rockwood K, Burns A, Gauthier S, DeKosky ST. Vascular cognitive impairment. Lancet Neurol. 2003 Feb;2(2):89-98. doi: 10.1016/s1474-4422(03)00305-3.

  PMID: 12849265 BACKGROUND

• Prince M, Bryce R, Albanese E, Wimo A, Ribeiro W, Ferri CP. The global prevalence of dementia: a systematic review and metaanalysis. Alzheimers Dement. 2013 Jan;9(1):63-75.e2. doi: 10.1016/j.jalz.2012.11.007.

  PMID: 23305823 BACKGROUND

• O'Brien JT, Markus HS. Vascular risk factors and Alzheimer's disease. BMC Med. 2014 Nov 11;12:218. doi: 10.1186/s12916-014-0218-y.

  PMID: 25385509 BACKGROUND

• Ono Y, Yamamoto T, Kubo KY, Onozuka M. Occlusion and brain function: mastication as a prevention of cognitive dysfunction. J Oral Rehabil. 2010 Aug;37(8):624-40. doi: 10.1111/j.1365-2842.2010.02079.x. Epub 2010 Mar 2.

  PMID: 20236235 BACKGROUND

• Weijenberg RA, Scherder EJ, Lobbezoo F. Mastication for the mind--the relationship between mastication and cognition in ageing and dementia. Neurosci Biobehav Rev. 2011 Jan;35(3):483-97. doi: 10.1016/j.neubiorev.2010.06.002. Epub 2010 Jun 12.

  PMID: 20547177 BACKGROUND

• Ohkubo C, Morokuma M, Yoneyama Y, Matsuda R, Lee JS. Interactions between occlusion and human brain function activities. J Oral Rehabil. 2013 Feb;40(2):119-29. doi: 10.1111/j.1365-2842.2012.02316.x. Epub 2012 May 25.

  PMID: 22624951 BACKGROUND

• Teixeira FB, Pereira Fernandes Lde M, Noronha PA, dos Santos MA, Gomes-Leal W, Ferraz Maia Cdo S, Lima RR. Masticatory deficiency as a risk factor for cognitive dysfunction. Int J Med Sci. 2014 Jan 10;11(2):209-14. doi: 10.7150/ijms.6801. eCollection 2014.

  PMID: 24465167 BACKGROUND

• Klineberg I, Palla S, Trulsson M. Contemporary relevance of occlusion and mastication. Int J Prosthodont. 2014 Sep-Oct;27(5):411-2. doi: 10.11607/ijp.2014.5.e. No abstract available.

  PMID: 25191880 BACKGROUND

• Hedberg L, Ekman U, Nordin LE, Smedberg JI, Skott P, Seiger A, Sandborgh-Englund G, Westman E, Kumar A, Trulsson M. Cognitive changes and neural correlates after oral rehabilitation procedures in older adults: a protocol for an interventional study. BMC Oral Health. 2021 Jun 9;21(1):297. doi: 10.1186/s12903-021-01654-5.

  PMID: 34107933 DERIVED

MeSH Terms

Conditions

Cognitive Dysfunction; Dementia; Cognition Disorders

Condition Hierarchy (Ancestors)

Neurocognitive Disorders; Mental Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases

Study Officials

• Mats Trulsson, Prof. DDS

  Karolinska Institutet

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: The investigator doing the cognitve assements is not informed about the allocation of the participants.It is not possible to mask the participants during the neuropsycological assessements.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: DDS, Senior Consultat, PhDs

Model Details: Longitudinal randomized controlled trial. After screening and informed consent the participants are randomly allocated to exeperimental or control group. Both groups undergoing intervention but the participants in the control group undergo one more test before the intervention to rule out the test-retest effect.

Study Record Dates

• First Submitted: June 26, 2020
• First Posted: July 7, 2020
• Study Start: November 2, 2018
• Primary Completion (Estimated): December 30, 2026
• Study Completion (Estimated): December 30, 2027
• Last Updated: September 26, 2025

Record last verified: 2025-03

Locations

SE (2)