A method to evaluate upper airway mechanics following intervention in snorers

Combination CPAP and bilateral hypoglossal nerve stimulation for obstructive sleep apnea in Treacher Collins syndrome: first case report

We report the first case of bilateral hypoglossal nerve stimulator implantation in a patient with Treacher Collins syndrome and very severe obstructive sleep apnea, who was initially intolerant of continuous positive airway pressure (CPAP) treatment. Novel bilateral hypoglossal nerve stimulation in combination with CPAP allowed near obliteration of snoring, improved sleep quality, and ability to maintain the CPAP mask in position in the setting of craniofacial changes associated with this condition.

CITATION

Wong ACL, Jones A, Stone A, MacKay SG. Combination CPAP and bilateral hypoglossal nerve stimulation for obstructive sleep apnea in Treacher Collins syndrome: first case report. J Clin Sleep Med. 2023;19(1):197-199.

Tratamiento con dispositivos orales para síndrome de apnea-hipopnea obstructiva del sueño (SAHOS)

El objetivo de este artículo es mejorar la práctica con dispositivos orales (DO) por parte del odontólogo tratante, al alcanzar una adecuada selección del DO y brindar seguridad y efectividad al paciente. Con el uso de estos, se intenta disminuir la frecuencia o duración de los eventos respiratorios. Los DO están indicados en pacientes con ronquido primario, síndrome de apnea-hipopnea obstructiva del sueño (SAHOS) leve-moderado y SAHOS severo que no quieran o no toleren tratamiento con presión positiva. Además, se clasifican en aparatos de retención de lengua, aparatos no ajustables y ajustables, siendo estos últimos los más recomendados por ser dispositivos de avance mandibular (DAM), pues son hechos a la medida, ajustables y de arco dual. Su mecanismo de acción consiste en protruisión del maxilar inferior, adelantamiento del hueso hioides y apertura mandibular.Los DAM son más eficaces en pacientes jóvenes, con menor índice de masa corporal (IMC), circunferencia de cuello reducida, SAHOS posicional y mandíbula retrognática. Se pueden presentar efectos adversos como salivación excesiva, cambios oclusales y trastornos temporomandibulares. Se ha demostrado que los DAM tienen un impacto en la disminución del índice de apnea-hipopnea (IAH) y somnolencia diurna, mejoría en la oxigenación nocturna, función cardiovascular, calidad de vida y comportamiento neurocognitivo. Asimismo, los DAM son superiores al tratamiento con presión positiva de vía aérea (PAP) en adherencia. Se sugiere que la terapia combinada de DAM con PAP y otros tratamientos es promisoria para aquellos pacientes que responden de manera insuficiente a la monoterapia.

Surgical Approaches to Obstructive Sleep Apnea

Surgery in adult obstructive sleep apnea (OSA) has undergone significant advancement in recent years and continues to evolve. It is a modality of treatment used in the context of failed device use, specifically, failed continuous positive airway pressure or mandibular advancement splint. In this context, the role of surgery is either as salvage therapy or to facilitate better tolerance of device use. Other treatments such as weight loss, adjuvant nasal therapy (medical ± prephase nasal surgery) and positional devices may be combined with airway surgery. In general, patients with OSA are managed with in-hospital monitoring perioperatively.

Effects of mandibular advancement on upper airway dimension and collapsibility in patients with obstructive sleep apnea using dynamic upper airway imaging during sleep

OBJECTIVES

The objective of this study was to evaluate the effects of mandibular advancement on oropharyngeal dimension and collapsibility and reveal the predominate site of change produced by mandibular advancement in patients with obstructive sleep apnea (OSA).

STUDY DESIGN

Sixteen adults (13 males and 3 females) with symptomatic mild to severe OSA participated. Custom-made silicone mandibular positioners were used to keep the mandible at 67% of maximum advancement. Changes in the oropharyngeal size and collapsibility with mandibular advancement were evaluated using ultrafast computed tomography taken during wakefulness and midazolam-induced sleep. Cross-sectional areas were assessed using electron beam tomography at 4 levels: high retropalatal (HRP), low retropalatal (LRP), high retroglossal (HRG), and low retroglossal (LRG).

RESULTS

During sleep, the minimum cross-sectional areas decreased 36.5%, 67.8%, 75.5%, and 65.8% at each level of HRP, LRP, HRG, and LRG respectively, as compared with those measured during wakefulness. Mandibular advancement during sleep increased 75.7%, 141.3%, 128.1%, and 119.9% at each level. The oropharynx showed 70.3%, 110.4%, 140.3%, and 156.9% increase in the Collapsibility Indices during sleep at each level of HRP, LRP, HRG, and LRG, respectively, compared with wakefulness. However, collapsibility indices decreased 29.1%, 23.2%, 21.4%, and 34.1% at each level with mandibular advancement.

CONCLUSION

Mandibular advancement increases oropharyngeal diameter and decreases oropharyngeal collapsibility during midazolam-induced sleep respiration at the retropalatal as well as the retroglossal region in most patients with OSA.

Snoring source identification and snoring noise prediction

This paper investigates the snoring mechanism of humans by applying the concept of structural intensity to a three-dimensional (3D) finite element model of a human head, which includes: the upper part of the head, neck, soft palate, hard palate, tongue, nasal cavity and the surrounding walls of the pharynx. Results show that for 20, 40 and 60Hz pressure loads, tissue vibration is mainly in the areas of the soft palate, the tongue and the nasal cavity. For predicting the snoring noise level, a 3D boundary element cavity model of the upper airway in the nasal cavity is generated. The snoring noise level is predicted for a prescribed airflow loading, and its range agrees with published measurements. These models may be further developed to study the various snoring mechanisms for different groups of patients.

Effect of a non-adjustable oral appliance on upper airway morphology in obstructive sleep apnoea

BACKGROUND

To evaluate the effect of oral appliance (OA) on upper airway morphology and its relationship with treatment response in subjects with obstructive sleep apnoea (OSA).

METHODS

Symptomatic OSA subjects were recruited. Non-adjustable OA was custom made. Variables examined at baseline and while wearing the device at 2 months included polysomnographic data, computed tomographic measurements of upper airway cross sectional area at level of velopharynx (VA) and hypopharynx (HA), upper airway volume, and cephalometric parameters. Treatment outcome was based on post-treatment apnoea-hypopnoea index (AHI).

RESULTS

Forty patients were recruited and 23 (7 women) completed the study. They were middle-aged (49, 40-58 years) (median, interquartile range) and overweight (BMI 26, 23.3-29.5 kg/m2), with moderate OSA (AHI 26.4, 14.1-36). The overall post treatment AHI was 8.4 (2.4-12.5), with 14 (61%) patients showing good response (AHI<10), and the other 9 patients showing moderate response (>50% reduction in AHI but still 10). OA decreased the cross-sectional area of the HA (P=0.046), showed a trend of decreasing the ratio of cross-sectional area of the HA to cross-sectional area of the VA (P=0.053) and significantly increased the overall upper airway volume (P=0.006, n=11). No significant relationship between upper airway parameters and treatment outcome was identified.

CONCLUSIONS

OA altered upper airway morphometry towards a profile consistent with decreased propensity to collapse, which may thus have contributed to improvement of OSA.

A practical method for describing patterns of tongue-base narrowing (modification of Fujita) in awake adult patients with obstructive sleep apnea

PURPOSE

The purpose of the present study was to evaluate a clinically practical classification system for tongue-base narrowing and to assess intrarater and interrater reliability of the proposed system.

PATIENTS AND METHODS

A population of 248 consecutive patients with polysomnographically proven upper airway obstructive pathology were evaluated (using the hypotonic method) for evidence of upper airway narrowing with the commonly available techniques of fiberoptic nasopharyngoscopy, clinical examination and lateral cephalometric analysis.

RESULTS

Four basic patterns of tongue-base narrowing have been discerned to occur in awake adult patients with diagnosed obstructive upper airway pathology. These include type A (high tongue base), type B1 (high tongue base with retroepiglottic narrowing), type B2 (diffuse tongue-base narrowing), and type 3 (isolated retrogepiglottic narrowing). These recognized patterns have been found to have high intraexaminer and interexaminer reliability. No statistical correlation was found between tongue-base pattern and severity of obstructive sleep apnea, age, or facial skeletal pattern. Males had a higher percentage of type C pattern, and the type A pattern patients tended to have a higher body mass index.

CONCLUSIONS

Potential future uses of this classification system include the ability to more practically assess and describe anatomic locations of tongue-base narrowing and to permit an improved means of comparing the results of various surgical and nonsurgical therapies.

Acute effects of palatopharyngoplasty on airway collapsibility

OBJECTIVE

The lateral pharyngeal walls contribute to obstruction in obstructive sleep apnea. These structures may be unaffected by uvulopalatopharyngoplasty. This was evaluated by retrospective review of upper airway observations after palatopharyngoplasty.

METHODS AND PATIENTS

The retropalatal airway was endoscopically observed intraoperatively after each procedure in 7 patients. The airway was dilated with nasal continuous positive airway pressure.

RESULTS

Transpalatal advancement pharyngoplasty increased the area 120% (P = 0.001), and closing pressure decreased 9.2 cm H2 O (P < 0. 01). The maximal anteroposterior length (MAX-AP) and maximal lateral radius increased 90% (P = 0.01) and 60% (P < 0.001), respectively. MAX-AP changed in 2, both increased in 4, and maximal lateral radius increased in 1 patient. The closing pressure change correlated with airway size (r 2 = 0.44, P < 0.05); airway shape was associated with change in MAX-AP (r 2 = 0.51, P < 0.07).

CONCLUSIONS

Both the anteroposterior and lateral wall dimensions are altered by palatopharyngoplasty techniques, which increase retropalatal airway size. This is not limited to facial advancement surgery.