Aslı ÇAKIR, Mustafa Cenk ECEVİT, Hüseyin ÖZAY

Retronasal Olfaction Test Methods: A Systematic Review

Background: This report produces a bibliographic study of psychophysical tests proposed clinical assessments of retronasal olfaction.Aims: We review how these tests can be utilized and discuss their methodological properties.Study Design: Systematic review.Methods: We undertook a systematic literature review investigating the retronasal olfaction test methods. PubMed, the free online MEDLINE database on biomedical sciences, was searched for the period from 1984 to 2015 using the following relevant key phrases: “retronasal olfaction”, “orthonasal olfaction”, “olfaction disorders”, and “olfaction test”. For each of the selected titles cited in this study, the full manuscript was read and analyzed by each of the three authors of this paper independently before collaborative discussion for summation and analytical reporting. Two reviewers independently read the abstracts and full texts and categorised them into one of three subgroups as follow, suitable, not-suitable, and unsure. Then they cross-checked the results, and a third reviewer decided assigned the group “unsure” to either the suitable group or the not-suitable group. Fifty eight studies revealed as suitable for review by two authors whereas 13 found not suitable for review. The total amount of 60 uncertain (unsure) or differently categorized articles were further examined by the third author which resulted in 41 approvals and 19 rejections. Hence 99 approved articles passed the next step. Exclusion criteria were reviews, case reports, animal studies, and the articles of which methodology was a lack of olfaction tests. By this way excluded 69 papers, and finally, 30 original human research articles were taken as the data.Results: The study found that the three most widely used and accepted retronasal olfaction test methods are the retronasal olfaction test, the candy smell test and odorant presentation containers. All of the three psychophysical retronasal olfaction tests were combined with orthonasal tests in clinical use to examine and understand the smell function of the patient completely. There were two limitations concerning testing: “the lack concentrations and doses of test materials” and “performing measurements within the supra-threshold zone”.Conclusion: The appropriate test agents and optimal concentrations for the retronasal olfaction tests remain unclear and emerge as limitations of the retronasal olfaction test technique. The first step to overcoming these limitations will probably require identification of retronasal olfaction thresholds. Once these are determined, the concept of retronasal olfaction and its testing methods may be thoroughly reviewed.

PDF

___

Frasnelli J, Hummel T. Olfactory dysfunction and daily life. Eur Arch Otorhinolaryngol. 2005;262:231-5.
Santos DV, Reiter ER, DiNardo LJ, Costanzo RM. Hazardous events associated with impaired olfactory function. Arch Otolaryngol Head Neck Surg 2004;130:317-9.
Bushdid C, Magnasco MO, Vosshall LB, Keller A. Humans can discriminate more than 1 trillion olfactory stimuli. Science 2014;343:1370-2.
Jankowski R. Revisiting human nose anatomy: phylogenic and ontogenic perspectives. Laryngoscope 2011;121:2461-7.
Guyton A.C, Hall J.E. Tıbbi Fizyoloji, Editor: Cavusoglu H. 11th edt. İstanbul, Nobel Medicine Bookstore, 2007;663-70.
Small DM, Gerber JC, Mak YE, Hummel T. Differential neural responses evoked by orthonasal versus retronasal odorant perception in humans. Neuron 2005;47:593-605.
Bojanowski V, Hummel T. Retronasal perception of odors. Physiol Behav 2012;107:484-7.
Halpern BP. Retronasal and orthnasal smelling. Chemo Sense 2004;6:1-7.
Evren C, Yigit VB, Cinar F. Subjective assessment of olfactory function. Kulak Burun Bogaz Ihtis Derg 2015;25:59-64.
Hummel T, Sekinger B, Wolf SR, Pauli E, Kobal G. 'Sniffin' sticks': olfactory performance assessed by the combined testing of odor identification, odor discrimination and olfactory threshold. Chem Senses 1997;22:39-52.
Doty RL, Shaman P, Kimmelman CP, Dann MS. University of Pennsylvania Smell Identification Test: arapid quantitative olfactory function test for the clinic. Laryngoscope 1984;94:176-8.
Cain WS, Gent JF, Goodspeed RB, Leonard G. Evaluation of olfactory dysfunction in the Connecticut Chemosensory Clinical Research Center. Laryngoscope 1988;98:83-8.
Rombaux P, Weitz H, Mouraux A, Nicolas G, Bertrand B, Duprez T, et al. Olfactory function assessed with orthonasal and retronasal testing, olfactory bulb volume, and chemosensory event-related potentials. Arch Otolaryngol Head Neck Surg 2006;132:1346-51.
Tsukatani T, Reiter ER, Miwa T, Costanzo RM. Comparison of diagnostic findings using different olfactory test methods. Laryngoscope 2005;115:1114-7.
Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.handbook.cochrane.org.
Heilmann S, Strehle G, Rosenheim K, Damm M, Hummel T. Clinical assessment of retronasal olfactory function. Arch Otolaryngol Head Neck Surg 2002;128:414-8.
Landis BN, Giger R, Ricchetti A, Leuchter I, Hugentobler M, Hummel T, et al. Retronasal olfactory function in nasal polyposis. Laryngoscope 2003;113:1993-7.
Konstantinidis I, Triaridis S, Triaridis A, Petropoulos I, Karagiannidis K, Kontzoglou G. How do children with adenoid hypertrophy smell and taste? Clinical assessment of olfactory function pre- and post-adenoidectomy. Int J Pediatr Otorhinolaryngol 2005;69:1343-9.
Pfaar O, Landis BN, Frasnelli J, Hüttenbrink KB, Hummel T. Mechanical obstruction of the olfactory cleft reveals differences between orthonasal and retronasal olfactory functions. Chem Senses 2006;31:27-31.
Rombaux P, Weitz H, Mouraux A, Nicolas G, Bertrand B, Duprez T, et al. Olfactory function assessed with orthonasal and retronasal testing, olfactory bulb volume, and chemosensory event-related potentials. Arch Otolaryngol Head Neck Surg 2006;132:1346-51.
Leon EA, Catalanotto FA, Werning JW. Retronasal and orthonasal olfactory ability after laryngectomy. Arch Otolaryngol Head Neck Surg 2007;133:32-6.
Croy I, Hoffmann H, Philpott C, et al. Retronasal testing of olfactory function: an investigation and comparison in seven countries. Eur Arch Otorhinolaryngol 2014;271:1087-95.
Landis BN, Frasnelli J, Reden J, Lacroix JS, Hummel T. Differences between orthonasal and retronasal olfactory functions in patients with loss of the sense of smell. Arch Otolaryngol Head Neck Surg 2005;131:977-81.
Rombaux P, Weitz H, Mouraux A, Nicolas G, Bertrand B, Duprez T, et al. Olfactory function assessed with orthonasal and retronasal testing, olfactory bulb volume, and chemosensory event-related potentials. Arch Otolaryngol Head Neck Surg 2006;132:1346-51.
Rombaux P, Bertrand B, Keller T, Mouraux A. Clinical significance of olfactory event-related potentials related to orthonasal and retronasal olfactory testing. Laryngoscope 2007;117:1096-101
Rombaux P, Mouraux A, Collet S, Eloy P, Bertrand B. Usefulness and feasibility of psychophysical and electrophysiological olfactory testing in the rhinology clinic. Rhinology 2009;47:28-35.
Landis BN, Cao Van H, Guinand N, Horvath J, Haehner A, Savva E, et al. Retronasal olfactory function in Parkinson's disease. Laryngoscope 2009;119:2280-3.
Fleiner F, Dahlslett SB, Schmidt F, Harms L, Goektas O. Olfactory and gustatory function in patients with multiple sclerosis. Am J Rhinol Allergy 2010;24:e93-7.
Roudnitzky N, Bult JH, de Wijk RA, Reden J, Schuster B, Hummel T. Investigation of interactions between texture and ortho- and retronasal olfactory stimuli using psychophysical and electrophysiological approaches. Behav Brain Res 2011;216:109-15.
Rombaux P, Huart C, Deggouj N, Duprez T, Hummel T. Prognostic value of olfactory bulb volume measurement for recovery in postinfectious and posttraumatic olfactory loss. Otolaryngol Head Neck Surg 2012;147:1136-41.
Salihoğlu M, Kendirli MT, Altundağ A, et al. The effect of obstructive sleep apnea on olfactory functions. Laryngoscope 2014;124:2190-4.
Cayonu M, Salihoglu M, Altundag A, Tekeli H, Kayabasoglu G. Grade 4 tonsillar hypertrophy associated with decreased retronasal olfactory function: a pilot study. Eur Arch Otorhinolaryngol 2014;271:2311-6.
Salihoglu M, Altundag A, Cayonu M, Tekeli H. An investigation of retronasal testing of olfactory function in a Turkish population. Med Sci Monit 2014;20:569-76.
Altundag A, Salihoglu M, Cayonu M, Tekeli H. Clinical assessment of olfactory functions in children who underwent adenotonsillectomy during pre- and post-operative period. Int J Pediatr Otorhinolaryngol 2014;78:1138-42.
Altundag A, Cayonu M, Kayabasoglu G, Salihoglu M, Tekeli H, Cayonu S, et al. The evaluation of olfactory function in individuals with chronic halitosis. Chem Senses 2015;40:47-51.
Reychler G, Colbrant C, Huart C, Le Guellec S, Vecellio L, Liistro G, et al. Effect of three-drug delivery modalities on olfactory function in chronic sinusitis. Laryngoscope 2015;125:549-55.
Renner B, Mueller CA, Dreier J, Faulhaber S, Rascher W, Kobal G. The candy smell test: a new test for retronasal olfactory performance. Laryngoscope 2009;119:487-95.
Haxel BR, Bertz-Duffy S, Faldum, Trellakis S, Stein B, Renner B, et al. The Candy Smell Test in clinical routine. Am J Rhinol Allergy 2011;25:e145-8.
Pierce J, Halpern BP. Orthonasal and retronasal odorant identification based upon vapor phase input from common substances. Chem Senses 1996;21:529-43.
Sun BC, Halpern BP. Identification of air phase retronasal and orthonasal odorant pairs. Chem Senses 2005;30:693-706.
Chen V, Halpern BP. Retronasal but not oral-cavity-only identification of "purely olfactory" odorants. Chem Senses 2008;33:107-18.
Dalton P, Cowart B, Dilks D, Gould M, Lees PS, Stefaniak A, et al. Olfactory function in workers exposed to styrene in the reinforced-plastics industry. Am J Ind Med 2003;44:1-11. Dragich AM, Halpern BP. An oral-cavity component in retronasal smelling of natural extracts. Physiol Behav 2008;93:521-8.
Bolton B, Halpern BP. Orthonasal and retronasal but not oral-cavity-only discrimination of vapor-phase fatty acids. Chem Senses 2010;35:229-38.
Green BG, Nachtigal D, Hammond S, Lim J. Enhancement of retronasal odors by taste. Chem Senses 2012;37:77-86.
Chukir T, Darlington RB, Halpern BP. Shared retronasal identifications of vapor-phase 18-carbon fatty acids. Chem Senses 2013;38:343-53.