06 September 2021

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Severe Obstructive Sleep Apnea Syndrome solved with an orthodontic mandibular advancement device: a case report

Authors: Giovanni Bruno, Alberto De Stefani, Luca Mezzofranco, Giuliano Irlandese, Antonio Gracco

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Obstructive Sleep Apnea Syndrome (OSAS) is a chronic sleep respiratory disturbances (DRS) result from a completed (apnea) or partial (hypopnea) upper airways obstruction, most often at the oropharyngeal level, alternating with brief hyperventilation. Continuous Positive Airway Pressure (CPAP) is actually considered the gold standard therapy for OSAS patients to reduces the symptomatology and the apnea-hypopnea index (AHI), but it is not well tolerated by many patients for the encumbrance and the noise. Orthodontic treatment consists in the application of an intraoral Mandibular Advancement Device (MAD) with the aim of advancing jaw and tongue, having as final objective the opening of the pharyngeal air space, thus freeing the passage of air.

Material and methods 
A 61-year-old man affected by severe (54.8 AHI, 82% nadir) OSAS came for an orthodontic evaluation after inferior turbinate, pharyngoplasty, uvuloplasty surgery and drug induced sleep endoscopy (DISE) that evaluate a IV degree anterior-posterior collapse in the hypopharynx, II degree circular collapse in oropharynx and IV degree circular collapse in in the nasopharynx. At the anamnesis and objective examination 21 Epworth Sleepiness Scale (ESS) score, 43.5 mm neck circumference, 8 mm of maximum protrusion and 6 mm of maximum retrusion (evaluated with George Gauge) and mandibular retrusion were evaluated. The airways volume was evaluated with a CBCT 12’ FOV and from the cephalometric analysis was evaluated a second skeletal class which had confirm the mandibular retro-position. The initial polysomnography revealed a severe OSAS (54.8 AHI) with a positional component (57.1 supine AHI) and snoring index (SI) of 168.3 per hour. Oxygen average saturation was 94%, oxygen desaturation index (ODI) was 50.5 and nadir was 82%. The principal aim of the treatment was to improve the general health condition of the patient, reduce the AHI and the polysomnography parameters.

Discussion and Conclusion
Orthodontic treatment consisted in a mandibular advancement device (Somnodent Flex) and vertical elastics (3/16’’ 56,7g). The latest post-treatment polysomnography revealed a 1.6 AHI, 91% nadir and no episodes of oxygen desaturation lower than 90%. Otolaryngology surgery, orthodontic evaluation and a corrected management of an OSAS adult patient improve the AHI score and oxygen saturation. It is necessary to select correctly the patient through the DISE evaluation. Orthodontic and multidisciplinary approach show a great outcome for a severe OSAS patient with no compliance to CPAP treatment.

Clinical Significance
Orthodontic evaluation permit to evaluate an adequate mandibular protrusion, absence of temporomandibular disorders, dental or periodontal problems. MAD treatment in a severe OSAS patient confirms, with an adequate compliance, satisfactory results a valid alternative to CPAP use. A motivational interview with the patient shows an essential aspect to maintain the compliance to MAD use throughout life and this is the reason why annual checks are recommended.