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RecruitingNCT04791436Updated May 13, 2024

Oral and Olfactory Complications of Recovered COVID-19 Patients

An observational study in Oral Complication, Dysgeusia and Olfactory Disorder, sponsored by University of Giessen. Recruiting at 1 site in Germany. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-05-13.

Sponsored by University of Giessen · Observational

From the registry’s dates

  • Primary completion was expected by Jan 2025, 1 year 9 months ago, but the record still lists the study as recruiting.
  • Started May 2021; still recruiting 5 years 6 months later.
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
402
Ages
18 Years and older
Sex
All
01

Study summary

This cohort study aims to investigate the long-standing chemosensory disorders and oral manifestation after recovery of the COVID-19 illness. A correlation between the long-standing symptoms and the COVID-19 severity grade will be very important to understand and clarify the aetiology of these symptoms.

Read the detailed description

This prospective cohort study aims to investigate the long-standing chemosensory disorders and oral manifestation after recovery of the COVID-19 illness. A correlation between the long-standing symptoms and the COVID-19 severity grade will be very important to understand and clarify the aetiology of these symptoms.

Study objectives:

  1. To describe the frequency and severity of oral signs and chemosensory disorders that persist after the recovery of COVID-19 and to examine whether "taste disorders" can be discriminated into an- or hypogeusia and an- or hyposmia.
  2. To report any correlation between the severity grade of COVID-19 and the resulting standing symptoms.
  3. To describe the oral microbiome after infection with COVID-19 and to describe possible changes in comparison to normal healthy individuals.

Clinical and -if indicated- radiological examination to assess the long-term oral and chemosensory impairment and complaints of COVID-19 patients after their recovery shall be performed in an interdisciplinary setting of Maxillofacial Surgery, ENT and Medical Microbiology.

The study subjects will be divided into three groups according to the severity grade of illness: non-hospitalized, hospitalized, and intensive care patients. All adult COVID-19 recovery patients (exceeding the age of 18) will be included in the study. The time between illness and study recruitment shall be at least 3 months. Exclusion criteria are psychiatric or neurological diseases, previous trauma, surgery or radiotherapy in the oral or nasal cavities, pre-existing taste or smell dysfunctions or chronic rhinosinusitis.

The study variables include age, sex, co-morbidities, possible causes of exclusion from the study. The oral health assessment will be performed by examination of: periodontal status, assessment of oral lesions, a radiological examination by using panoramic x-ray if clinically indicated, photo documentation, objective evaluation of the olfactory and gustatory functions with psychophysical tests. The gustatory and olfactory function will be tested by using the combined Burghart Screening 12 test containing smelling sticks and taste strips (Fa. MediSense, Groningen, Netherlands). Evaluation of taste and smell is performed by offering the sticks/strips and demand a forced multiple choice.

02

Conditions studied

  • Oral Complication
  • Dysgeusia
  • Olfactory Disorder

Keywords

  • COVID-19
  • Oral Manifestations
  • Olfactory Manifestations
03

In context

Dysgeusia

52 studies on the registry are indexed under Dysgeusia; 12 are open to participants now.

This study's planned enrollment of 402 is above the median of 104 across 22 observational studies indexed under Dysgeusia.

Browse Dysgeusia studies →

Lead sponsor

University of Giessen is the lead sponsor of 95 studies on the registry; 22 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes
Sampling method
Probability sample

Study population

Study subjects will be divided into three groups according to the severity grade of illness: non-hospitalized, hospitalized, and intensive care patients.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • All adult COVID-19 recovery patients (exceeding the age of 18) will be included in the study. The time between illness and study recruitment shall be at least 3 months.

Exclusion criteria

Exclusion Criteria:

  • Exclusion criteria are psychiatric or neurological diseases, previous trauma, surgery or radiotherapy in the oral or nasal cavities, pre-existing taste or smell dysfunctions or chronic rhinosinusitis.
05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
402 participants (estimated)
Patient registry
No

Groups and cohorts

  • Mild Illness

    Recovered COVID-19 patients who experienced a mild clinical course

    Diagnostic Test: Gustatory and olfactory function test · Diagnostic Test: Molecular assessment of saliva

  • Moderate Illness

    Recovered COVID-19 patients who experienced a moderate clinical course

    Diagnostic Test: Gustatory and olfactory function test · Diagnostic Test: Molecular assessment of saliva

  • Severe Illness

    Recovered COVID-19 patients who experienced a severe clinical course

    Diagnostic Test: Gustatory and olfactory function test · Diagnostic Test: Molecular assessment of saliva

Interventions

  • Diagnostic testGustatory and olfactory function test

    The gustatory and olfactory function will be tested by using the combined Burghart Screening 12 test containing smelling sticks and taste strips (Fa. MediSense, Groningen, Netherlands). Evaluation of taste and smell is performed by offering the sticks/strips and demand a forced multiple choice.

  • Diagnostic testMolecular assessment of saliva

    Saliva samples will be taken for molecular biological determination of the oral microbiome. The microbiome is determined at the Institute for Medical Microbiology by 16s-rRNA gene analysis with Next Generation Sequencing and bioinformatics.

06

What researchers measure

Primary outcomes

  1. Periodontal health

    Community Periodontal Index (CPI) of the World Health Organization (WHO) will be used to assess periodontal health (continuous variable)

    Time frame: At least 3 months after recovery of COVID-19

  2. Oral mucocutaneous lesions

    An intraoral examination will be carried out to assess the presence of any mucocutaneous lesions (dichotomous variable)

    Time frame: At least 3 months after recovery of COVID-19

  3. Gustatory function

    Burghart Sniffin' Sticks "Screening 12 Test" will be used to assess gustatory function (continuous variable)

    Time frame: At least 3 months after recovery of COVID-19

  4. Olfactory function

    Burghart Sniffin' Sticks "Screening 12 Test" will be used to assess olfactory function (continuous variable)

    Time frame: At least 3 months after recovery of COVID-19

07

Study locations

1 of 1 sites recruiting
  • Justus-Liebig University
    Gießen, Hesse 35392, Germany
    Recruiting
    • Sameh Attia · Contact
08

References and documents

Publications

  • Attia S, Howaldt HP. Impact of COVID-19 on the Dental Community: Part I before Vaccine (BV). J Clin Med. 2021 Jan 14;10(2):288. doi: 10.3390/jcm10020288. PubMed 33466777 ↗
  • Bottger S, Zechel-Gran S, Streckbein P, Knitschke M, Hain T, Weigel M, Wilbrand JF, Domann E, Howaldt HP, Attia S. A New Type of Chronic Wound Infection after Wisdom Tooth Extraction: A Diagnostic Approach with 16S-rRNA Gene Analysis, Next-Generation Sequencing, and Bioinformatics. Pathogens. 2020 Sep 28;9(10):798. doi: 10.3390/pathogens9100798. PubMed 32998201 ↗
  • Ammar N, Aly NM, Folayan MO, Mohebbi SZ, Attia S, Howaldt HP, Boettger S, Khader Y, Maharani DA, Rahardjo A, Khan I, Madi M, Shamala A, Al-Batayneh OB, Rashwan M, Pavlic V, Cicmil S, Galluccio G, Polimeni A, Mancino D, Arheiam A, Dama MA, Nyan M, Phantumvanit P, Kim JB, Choi YH, Castillo JL, Joury E, Abdelsalam MM, Alkeshan MM, Hussein I, Vukovic AP, Iandolo A, Kemoli AM, El Tantawi M. Knowledge of dental academics about the COVID-19 pandemic: a multi-country online survey. BMC Med Educ. 2020 Nov 2;20(1):399. doi: 10.1186/s12909-020-02308-w. PubMed 33138810 ↗
  • Ammar N, Aly NM, Folayan MO, Khader Y, Virtanen JI, Al-Batayneh OB, Mohebbi SZ, Attia S, Howaldt HP, Boettger S, Maharani DA, Rahardjo A, Khan I, Madi M, Rashwan M, Pavlic V, Cicmil S, Choi YH, Joury E, Castillo JL, Noritake K, Shamala A, Galluccio G, Polimeni A, Phantumvanit P, Mancino D, Kim JB, Abdelsalam MM, Arheiam A, Dama MA, Nyan M, Hussein I, Alkeshan MM, Vukovic AP, Iandolo A, Kemoli AM, El Tantawi M. Behavior change due to COVID-19 among dental academics-The theory of planned behavior: Stresses, worries, training, and pandemic severity. PLoS One. 2020 Sep 29;15(9):e0239961. doi: 10.1371/journal.pone.0239961. eCollection 2020. PubMed 32991611 ↗

Individual participant data

Plan to share: No

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Started May 2021 (actual). Primary completion is estimated for Jan 2025, 44 months after the start.

How these figures are worked out, and which studies are left out of them.

Registered
Mar 7, 2021
First posted
Mar 10, 2021
StartActual
May 1, 2021
Primary completionEst.
Jan 30, 2025
CompletionEst.
May 28, 2025
Last update
May 13, 2024
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on May 13, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04791436
Lead sponsor
University of Giessen
Collaborators
Masaryk University, University of Kiel
Responsible party
Sameh Attia (Head of the Dental Polyclinic, University of Giessen) — Principal investigator
First posted
Mar 10, 2021
Start date
May 1, 2021
Primary completion
Jan 30, 2025 (estimated)
Completion
May 28, 2025 (estimated)
Last update
May 13, 2024

Study contacts

Sameh Attia, MSc
Contact
Sameh.Attia@dentist.med.uni-giessen.de
00496419946110

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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