An interventional study of Smell training in Smell Dysfunction, Taste Dysfunction and Trigeminal Dysfunction, sponsored by University of Oslo. Completed at 1 site in Norway. Open to participants aged 18 Years to 80 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-06.
Sponsored by University of Oslo · Not applicable, Interventional, and Screening
Taste, smell, trigeminal and salivary function is impacted in post-COVID-19 patients
-COVID-19 diagnosis
Exclusion Criteria:
-Not COVID-19 diagnosis
Parosmia
Other: Smell training
Smell training
Smell
Olfactory (smell) function will be evaluated using the Twelve felt-tip Sniffin' Sticks test (Burghart Messtechnik GmbH, Holm, Germany). Participants are categorized into anosmic (score 0-6, no smell), hyposmic (score 7-10, reduced smell), and normosmic (score 11-12, normal smell), according to normative classification.
Time frame: two years
Taste
Gustatory (taste) function is assessed using Taste Strips impregnated with solutions of four different taste qualities (sweet, sour, salty, and bitter) in four different concentrations (Burghart Messtechnik GmbH, Holm, Germany). Participants are classified into ageusic (score 0, no taste), hypogeusic (score 1-8, reduced taste) and normogeusic (score 9-16, normal taste) using a normative classification. Participants are considered to have a specific ageusia if they are unable to detect all four different concentrations of a particular tastant.
Time frame: 2 years
Dry mouth
Xerostomia (oral dryness) iss categorized according to participants' self-reported perception as either no dry mouth (score 0), or dry mouth (score 1). Participants are asked whether the symptoms of xerostomia started before or after COVID-19 infection and are asked open-ended questions where they could describe their experience of oral dryness. Finally, they are asked to report whether there are food items that they had to refrain from eating because of parosmia, dysgeusia, dysesthesia or xerostomia.
Time frame: 2 years
Dysesthesia
Dysesthesia (oral burning sensation) iss categorized as either no dysesthesia (score 0), or dysesthesia (score 1). Participants report how often they experienced dysesthesia (constantly, daily, sometimes, periodically, during meals, in between meals), asked to describe where in the mouth they experienced dysesthesia (whole tongue, anterior tongue, lips, palate, buccal mucosa, other), and identify food items that enhanced the dysesthesia (spicy, sweet, sour, salty, bitter).
Time frame: 2 years
Documents are hosted by the registry — open the source record to download them.
Plan to share: Undecided
This study is completed, as verified in May 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University of Oslo