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Communications to the Editor |

Clarification of Sleep Study Procedures FREE TO VIEW

B. Gail Demko, DMD
Author and Funding Information

Newton Highlands, MA

Correspondence to: B. Gail Demko, DMD, P.O. Box 610230, Newton Highlands, MA 02461; e-mail: bgdemko@yahoo.com



Chest. 2001;119(2):673. doi:10.1378/chest.119.2.673
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Published online

To the Editor:

I attended the 14th Associated Professional Sleep Societies annual meeting, where Victor Hoffstein, MD, PhD, presented his article on the variable mandibular advancement appliance (MAA).1 On page 1512, the “Investigations” section, third paragraph, he states, “After the appliance was manufactured and final adjustments completed…polysomnography was performed with the appliance.”

I asked Dr. Hoffstein if the mandibular portion of the MAA was further advanced at the time of polysomnogram (PSG). Dr. Hoffstein’s co-author, Jeffrey Pancer, DDS, said each of the various sleep laboratories in the investigation had received a letter in which the sleep technicians were instructed to “adjust [the mandibular portion of the MAA] gently…if the patient is snoring during the night…until snoring ceases or, if the patient is experiencing obstructive apnea,…until no apneas are occurring” (Fig 1). Dr. Pancer said the sleep laboratory technicians followed these instructions inconsistently and that no records were kept of which MAAs were so adjusted.

In fact, the alteration of the appliance position by the technician at the time of the second PSG did not follow the article’s prescribed procedure. Rather than evaluating the performance of the oral appliance, the second PSG seems to have been an experiment in manipulating the MAA to its most effective position. Other publications in this field have used a patient/dentist-determined jaw position for follow-up, which makes the outcome data of this report impossible to compare with earlier published works. Furthermore, the data as presented may mislead the reader to believe that the particular MAA used (the Thornton anterior positioner [TAP]) may be more effective, especially in severe obstructive sleep apnea patients, than traditional therapeutic follow-up PSGs would indicate.

With no record of which MAA was further advanced, it is difficult to determine the following:

  1. Which or how many appliances required additional advancement beyond the position determined by the patient (“The final protrusion of the jaw was not recorded because the patients were instructed how to change the amount of protrusion depending on symptoms and did so regularly at home”).1

  2. Which appliances, advanced at the time of PSG, were later retracted by the patient to a more comfortable (and possibly less effective) position after the experimental PSG.

  3. Whether the mandibular position was less effective for the 44% of patients for whom no second PSG was completed. The reader has no indication of the percentage of MAAs that required additional advancement to maximize their effect.

The adjustment of the MAA at the time of the second PSG, with the specific intent of improving snoring and apnea/hypopnea index, cannot constitute an evaluation of the effectiveness of the appliance as positioned by the patient or dentist. Rather, the second PSG must be viewed as an experimental process that looks at the titratability of this MAA. If the PSG purporting to assess outcome was in fact experimental, the accuracy of the study must remain in question until another therapeutic follow-up PSG is conducted on all patients whose MAAs were adjusted at the time of the second PSG, permitting comparison of the results of the TAP appliance with the existing literature.

To clear up any possible confusion in either the dental or medical sleep fields, and to clarify further data summarized in this study, I request that this letter be published in CHEST at your earliest convenience.

Figure Jump LinkFigure 1. Laboratory technician instructions.Grahic Jump Location

References

Panzer, J, Al-Faifi, S, Al-Faifi, M, et al (1999) Evaluation of variable mandibular advancement appliance for treatment of snoring and sleep apnea.Chest116,1511-1518. [CrossRef] [PubMed]
 

Figures

Figure Jump LinkFigure 1. Laboratory technician instructions.Grahic Jump Location

Tables

References

Panzer, J, Al-Faifi, S, Al-Faifi, M, et al (1999) Evaluation of variable mandibular advancement appliance for treatment of snoring and sleep apnea.Chest116,1511-1518. [CrossRef] [PubMed]
 
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