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mise à jour du
16 octobre 2003
Arch otolaryngol head neck
2002; 128; 648-654
Long-term results of OLFACTION rehabilitation using the nasal airflow-inducing maneuver after total laryngectomy
- Polite Yawning -
F Hilgers, H Jansen et al.
Department of ORL Head Neck surgery
Cancer institute Amsterdam (NL)
pdf de l'article


Total laryngectomy has a wide range of adverse effects, mainly as a result of the permanent disconnection of the upper and lower airways. Not only is the natural voice lost, but other physiological systems, which require a more or less normal nasal airflow, are disrupted and/or hampered as well. This change in anatomy often leads to deterioration in pulmonary function, with an associated range of physical and psychosocial problems, and a loss (or at least a serious decrease) of the sense of smell and taste.
Olfaction is either a passive process that occurs during normal nasal breathing (so-called passive smelling) or an active process (so-called active-smelling or sniffing). Total laryngectomy inevitably results in the loss of passive smelling, and only a minority of patients are still able to actively smell anything.
In a recent study of 63 laryngectomees, we found that about two thirds of the patients were anosmic and that the rest had difficulty in smelling. Several techniques have been described that might generate an airflow in the nose and thereby restore olfactory function. However, these techniques have not been incorporated into routine rehabilitation methods, and their effectiveness has not yet been evaluated either.
Recently, we developed a technique that makes use of a simple physical mechanism by creating an "underpressure" in the oral cavity, which then generates a flow of air through the nose. Patients are instructed to make an extended yawning movement while keeping their lips securely closed and simultaneously lowering theirjaw, floor of the mouth, tongue, base of the tongue, and soft palate. The underpressure thus created in the oral cavity results in an airflow through the nose. This technique, which is easily mastered by the patient, is taught by explaining that this movement resembles what one does when yawning with the mouth closed, ie, so-called polite yawning. This polite yawning maneuver bas to be repeated rapidly to increase its effectiveness. In an intervention study, we were able to show that after only one 30-minute training session, 25 (57%) of the 44 laryngectomees were able to smell using this technique.

Although this polite yawning technique is potentially an important adjunct to the rehabilitation process, no data are available on the long-term use of this technique; eg, do patients continue to apply this method aftersome months or years and do they apply it in daily life? Therefore, a followup study was conducted to study long-term results. Also, because our original studies used complicated techniques to assess olfacton, function,in the prescrit study we also assessed whether a new simple odor detection test (ODT) could replace our previous method of odor testing.


[...] Comment : The correlation between the ODT-POPS combination and the SDT seems sufficient to justify our decision to replace this laborious combination (used in our previous study) with the much simpler SDT. The results with the combination are slightly better (54% vs 46%), however, which could mean that the threshold for being classified as a smeller might be somewhat lower with the combination ODT-POPS than with the SDT. This outcome might be attributable to the strict criterion of separating normosmia on the one hand from hyposmia/anosmia on the other. The SDT has a proven validity and reliability and for routine clinical practice the use of a single objective measure has clear advantages. Similar results were recently reported using the Sniffin Sticks odor test in a series of laryngectomees.This latter test, however, consists of more odors and uses different concentrations and is therefore much more time consuming. The simple SDT requires only a few minutes to be completed.


The main aim of the study was to establish whether a single training session in the past had a permanent effect on the use of the NAIM in daily life. The majority of the patients who participated in the original intervention study also took part in the present study (31 [63%] of 49 patients). Because only 4 patients refused to participate (one of them being a smeller), selection bias concerning the long-term results is probably minor.

It is remarkable that the percentage of smellers in this follow-up study is very similar to that found in the earlier intervention study (54% vs 57%, respectively). The effectiveness of the NAIM could be confirmed: there is a relationship between the correct execution of the NAIM, as judged on the video recording, and whether the laryngectomee was a smeller or a nonsmeller. However, the small number of patients (16) who are still performing the NAIM correctly indicates that a single training session may be insufficient to achieve effective long-term results. On the other hand, 2 patients made use of the NAIM an automatism whenever something in the environment urged them to do so.
In this way, they compensated for the loss of passive smelling, which is a "bonus" of normal nasal breathing and an important aspect of natural olfaction. As with other speech-language pathology problems, behavioral changes are difficult to achieve and repetition of the training is often a key to success. More intense training, focusing on the important movements (lowering of the floor of the mouth and the jaw while simultaneously avoiding breathing in) and the fast repetition of the NAIM is needed to restore olfaction in a higher percentage of patients and to make the NAIM into an automatism that may allow passive smelling to occur again. Two other aims are to perform the maneuver as discreetly as possible by trying to lower only the floor of the mouth and to reduce the movement of the jaw. This attempt to make the NAIM more inconspicuous is relevant, because one of the reasons reported by patients for no longer using the maneuver was that it was too noticeable.

Whether the patency of the nose and the volume of air that can be moved with the polite yawning maneuver have an influence on olfaction acuity is a question that cannot be answered by the findings of the present study. Although none of our patients had overt nasal obstruction, which was more or less ruled out by nasal endoscopy, it remains unclear whether improvement of nasal patency would have a beneficial effect on the olfactory end result, as recently has been suggested. ` Along with studies on the volume of air that can be moved with the NAIM, rhinometry could maybe provide more insight in this respect.

Some of the older literature suggests that there is a positive correlation between the quality of the esophageal voice and the olfaction acuity of the patient.We were not able to evaluate this aspect because all but 2 of the patients were using a voice prosthesis. Nevertheless, the afore mentioned relationship might be merely a result of the better control of the oropharyngeal musculature in good esophageal speakers, enabling them to pump air into the nasal cavity retronasally, as bas been advocated in the past.' However, we think that this retronasal route is not very important and that in the majority of cases the oropharyngeal movements result in an anteronasal flow of air.

It should also be noted that the SDT criterion of a normal sense of smell was strictly followed, ie, 7 or 8 of the odors scored correctly. Some of the patients scored fewer than 7 odors correctly and could be considered to be to some extent hyposmic and probably not totally anosmic, which might lead to an underestimation of the results of the olfaction rehabilitation. However, by applying the cutoff scores of the SDT, the norms of "normal" smelling can be used to compare the results of laryngectornecs.

Recently, Miwa et al reconfirmed the effects of olfactory impairment on the quality-of-life and level of disability. Patients reporting persistent olfactory impairment after previously documented olfactory loss indicate a higher level of disability and a lower quality of life than those with perceived resolution of olfactory compromise. These observations are in agreement with our carlier finding that laryngectomees who were able to smell reported having a better taste and appetite. They emphasize the benefits that can be gained from olfaction rehabilitation in laryngectomees.

Conclusions : Odor testing in individuals who have undergone a total laryngectoiny is now possible in a relatively simple way using the easily applied SDT. The NAIM (best explained to the laryngectomee as a polite yawning technique) is a patient-friendly method that can restore the sense of smell. However, a single training session is probably insufficient, and most patients may need more training. This intensified training may then serve to rehabilitate olfaction in a higher percentage of patients and to make this maneuver an automatism to compensate for the loss of passive smelling after total laryngectomy. In view of this reconfirmation that it is possible to restore olfaction in individuals after total laryngectomy, reliabilitation of the sense of smell should forni an integral part of the multidisciplinary postlaryngectomy rehabilitation program.