468 Optimizing treatment of the intra-oral negative air pressure for obstructive sleep apnea

Introduction The intra-oral negative air pressure device (iNAP) is designed to develop a negative pressure gradient in the oral cavity of the user. The pressure gradient provides a force to move the tongue and soft palate forward. Previous works show the treatment response rate of intra-oral pressure therapy varying between 25–79%. However, for those OSA patients with very high BMI or AHI, they may need higher pressure to achieve optimizing treatment outcome. Methods To provide an optimizing treatment of intra-oral pressure, 30 patients treated with iNAP successfully completed one baseline PSG and one treatment PSG with in-laboratory pressure adjustment. When conducting the iNAP titration PSG, the initial treatment pressure is 40mmHg. iNAP pressure should be increased by at least 10mmHg an interval no shorter than 15 min. In order to eliminate obstructive respiratory events, iNAP pressure should be increased when observe obstructive apnea or hypopnea or unambiguous snoring. Results A total of 30 patients presented their consent to participate in this study. The mean age of the patients was 51.2 ± 13.97 years, and their mean body mass index (BMI) was 25.87 ± 3.41 kg/m2. The mean baseline AHI was 39.59 ± 20.05 events/h, which decreased significantly to 8.17 ± 8.11 events/h. No significant change in sleep efficacy, and percentage of N1 stage was found in the treatment PSG. However, significant improvements in the percentage of N3 stage, Min SpO2, and arousal index were observed in the treatment PSG. Conclusion In this study, the clinical response rate, as defined by the Sher criteria, was 86% (26/30 patients), when the Tx PSG response was compared with the baseline values. Besides, the mean AHI under final titration pressure is 2.58. The results show that increasing intraoral pressure would help to further improve the sleep apnea. Support (if any) This study was sponsored by Somnics, Inc.

Fishes can use axial muscles as anchors or motors for powerful suction feeding

ABSTRACTSome fishes rely on large regions of the dorsal (epaxial) and ventral (hypaxial) body muscles to power suction feeding. Epaxial and hypaxial muscles are known to act as motors, powering rapid mouth expansion by shortening to elevate the neurocranium and retract the pectoral girdle, respectively. However, some species, like catfishes, use little cranial elevation. Are these fishes instead using the epaxial muscles to forcefully anchor the head, and if so, are they limited to lower-power strikes? We used X-ray imaging to measure epaxial and hypaxial length dynamics (fluoromicrometry) and associated skeletal motions (XROMM) during 24 suction feeding strikes from three channel catfish (Ictalurus punctatus). We also estimated the power required for suction feeding from oral pressure and dynamic endocast volume measurements. Cranial elevation relative to the body was small (<5 deg) and the epaxial muscles did not shorten during peak expansion power. In contrast, the hypaxial muscles consistently shortened by 4–8% to rotate the pectoral girdle 6–11 deg relative to the body. Despite only the hypaxial muscles generating power, catfish strikes were similar in power to those of other species, such as largemouth bass (Micropterus salmoides), that use epaxial and hypaxial muscles to power mouth expansion. These results show that the epaxial muscles are not used as motors in catfish, but suggest they position and stabilize the cranium while the hypaxial muscles power mouth expansion ventrally. Thus, axial muscles can serve fundamentally different mechanical roles in generating and controlling cranial motion during suction feeding in fishes.

Nipple Deformation and Peripheral Pressure on the Areola During Breastfeeding

Breastfeeding is a complex process where the infant utilizes two forms of pressure during suckling, vacuum and compression. Infant applied compression, or positive oral pressure, to the breast has not been previously studied in vivo. The goal of this study is to use a methodology to capture the positive oral pressure values exerted by infants' maxilla (upper jaw) and mandible (lower jaw) on the breast areola during breastfeeding. In this study, the positive and negative (vacuum) pressure values are obtained simultaneously on six lactating mothers. Parallel to the pressure data measurements, ultrasound images are captured and processed to reveal the nipple deformations and the displacements of infants' tongues and jaw movements during breastfeeding. Motivated by the significant differences in composition between the tissue of the breast and the nipple–areola complex, the strain ratio values of the lactating nipples are obtained using these deformation measurements along with pre- and postfeed three-dimensional (3D) scans of the breast. The findings show an oscillatory positive pressure profile on the breast under both maxilla and mandible, which differs from clinical indications that only the mandible of an infant moves during breastfeeding. The strain ratio varies between mothers, which indicates volume changes in the nipple during feeding and suggests that previous assumptions regarding strain ratio for nonlactating breasts will not accurately apply to breast tissue during lactation.

Examining the effects of ankyloglossia on swallowing function

Oropharyngeal dysphagia (OPD) involves difficulty during one or more of the stages of swallowing, resulting in difficulty moving the bolus from the mouth to the stomach. A deficit in tongue mobility, such as that found with ankyloglossia, may affect the oropharyngeal transit time of the bolus and predispose a person to OPD. This study was conducted to examine the possible relationship between tongue tie and oropharyngeal dysphagia. Data were gathered on 8 participants (5 females, 3 males) between the ages of 12-43 years. The Lingual Frenulum Protocol (Marchesan, 2012) was used to determine tongue tie. An Iowa Oral Pressure Instrument (IOPI) measured tongue tip, tongue dorsum, and lip strength, and a combination of electromyography, and the five- finger palpation method measured laryngeal timing. Measurements were compared with normative data from Holzer (2011). Results revealed that participants with ankyloglossia had signs of oral stage dysphagia, including reduced articulator strength (tongue tip and dorsum, and lips) and reduced masseter activity. Oropharyngeal transit times were not significantly different from the norms.

Development of Velopharyngeal Closure for Vocalization During the First 2 Years of Life

PurposeThe vocalizations of young infants often sound nasalized, suggesting that the velopharynx is open during the 1st few months of life. Whereas acoustic and perceptual studies seemed to support the idea that the velopharynx closes for vocalization by about 4 months of age, an aeromechanical study contradicted this (Thom, Hoit, Hixon, & Smith, 2006). Thus, the current large-scale investigation was undertaken to determine when the velopharynx closes for speech production by following infants during their first 2 years of life.MethodThis longitudinal study used nasal ram pressure to determine the status of the velopharynx (open or closed) during spontaneous speech production in 92 participants (46 male, 46 female) studied monthly from age 4 to 24 months.ResultsThe velopharynx was closed during at least 90% of the utterances by 19 months, though there was substantial variability across participants. When considered by sound category, the velopharynx was closed from most to least often during production of oral obstruents, approximants, vowels (only), and glottal obstruents. No sex effects were observed.ConclusionVelopharyngeal closure for spontaneous speech production can be considered complete by 19 months, but closure occurs earlier for speech sounds with higher oral pressure demands.