Fernanda Almeida

Background: Obstructive sleep apnea (OSA) poses significant impairments to overall health and quality of life in adults. To date, the role of palatal morphology in the etiology of OSA in adults remains unclear. Maxillary expansion has recently been proposed as treatment for adult OSA, albeit with limited evidence. A fundamental understanding of palatal morphology in adults with OSA is necessary to evaluate the risks and benefits of maxillary expansion in adults with OSA. This study aimed to provide a comprehensive evaluation of palatal morphology using dental study models of adult patients with OSA.Methods: A retrospective study was conducted on 112 adult patients with OSA and/or snoring seeking mandibular advancement oral appliance therapy at a private practice clinic consecutively between May 2019 and April 2023. Medical and dental records, including baseline sleep apnea evaluation studies, and digital dental study models were collected. Conventional and geometric morphometrics were employed to characterize palatal morphology and to investigate the relationship between palatal morphology and the severity of OSA in adults.Results: The characterization of palatal morphology in our sample of adults with OSA showed similar maxillary inter-tooth widths as published norms for untreated ‘healthy’ adults. Conventional morphometrics, and the analysis of palatal shape through geometric morphometrics revealed no significant correlation with severity of obstructive sleep apnea (OSA) in adults.Conclusion: Palatal morphology and transverse maxillary arch dimensions are not correlated to severity of OSA in adults.

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Introduction: There are no reliable predictors of treatment outcomes for oral appliance therapy (OAT) in treating obstructive sleep apnea (OSA). The purpose of this study is to determine if baseline snoring can be used as a reliable predictor of treatment outcomes for OAT.Methods: This retrospective study extracted snoring data from two trials investigating the efficacy of the mandibular advancement device (MAD) and tongue stabilizing device (TSD) to treat OSA. Both trials collected data before and after treatment with a Level III sleep monitor. Only adult participants diagnosed with OSA with completed sleep studies before and after treatment with OAT were included. Each sleep study generated a report summarizing the snoring outcomes and respiratory events of the night, including the Respiratory Effort Index (REI). Patients were dichotomized as either a treatment responder or non-responder; patients with at least a 50% reduction in REI from baseline were considered treatment responders. Baseline snoring of treatment responders were then compared to the non-responders.Results: There were 34 participants in the MAD trial and 12 in the TSD trial. The MAD and TSD had a sight decrease in snoring loudness, however only the MAD had a significant decrease in the number of snoring events by 54%. There were no significant differences in baseline snoring between treatment responders and non-responders for either the MAD or the TSD. However, for the MAD, there was a significant negative correlation between baseline number of snoring events, loudness, and duration with change in REI. These results indicate that the more severe baseline snoring, the less change in REI after treatment with MAD. Baseline snoring was not a strong predictor of treatment outcomes for the TSD. Conclusions: The MAD and TSD can manage both primary and OSA related snoring, however the main improvement will be seen in the reduction of snoring events for the MAD. Baseline number of snoring events, loudness, duration were seen as better predictors of treatment outcomes for the MAD than the TSD. However, future studies are still necessary to validate the clinical merit of these results.

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Introduction: With a reported prevalence of up to 5%, pediatric obstructive sleep apnea syndrome (OSAS) is a common childhood affliction. Consequences associated include growth delay, metabolic disturbance, impaired cognition, cardiovascular morbidity, and wake-time behaviour. Altered craniofacial morphology such as backwardly positioned jaws, small upper jaw/lower jaw ratios, and long narrow faces have been associated with pediatric OSAS. Standardized craniofacial digital photography is a readily available and safe imaging method that has been used in adult study populations; however, it has yet to be utilized in a pediatric population to assess its utility as a screening tool for OSAS. Objective: Utilizing a systematic clinical examination, the prevalence of altered craniofacial morphology in children referred for overnight polysomnography at BC Children’s Hospital will be assessed. Calibrated digital photographs will be analyzed to extrapolate any craniofacial findings associated with pediatric OSAS. Methods: Patients aged 4-16 were recruited at BCCH to participate, undergoing an extra-oral and intra-oral orthodontic exam, the taking of one frontal and one lateral photograph, and completion of a standardized sleep questionnaire by the Parent/Guardian. Results: 65 participants (29 female, 36 male, mean age 8.9 ± 3.1 years) were compared based on their AHI. 27 children had an AHI 2/h (deemed not to have sleep apnea), 21 had mild OSAS (AHI 2 to 5/h), and 17 children were found to have severe OSAS (AHI >5/h). 19/65 participants (29.2%) were obese, and excluded from final analysis. Of the 44 remaining children, no significant differences were found for any direct clinical measurements between children with and without OSAS. Analysis of the standardized craniofacial photographs revealed that children with OSAS had a more obtuse cervicomental angle (7° increase), and an increase in lateral facial height (6 mm increase). An increasing cervicomental angle, intercanthal distance and cricomental distance were all correlated with the severity of OSAS. Conclusion: Aside from increases in cervicomental angle and lateral facial height, this study suggests altered craniofacial morphology may not be significantly associated with pediatric OSAS. Standardized craniofacial photography, in particular the measure of cervicomental angle, shows promise as a potential screening tool for OSAS, but requires further research.

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Objectives: Obstructive Sleep Apnea prevalence is substantially higher in men and subjects with higher body mass indexed. OSA is present in 41% of individuals with a BMI>28 kg/m², and in up to 78% in morbidly obese patients. Obesity alone is not the sole cause of OSA and craniofacial morphology is also a key determinant of the predisposition to airway collapse. There is still controversial data on the craniofacial characteristics of obese OSA patients and we hypothesize that the age when individuals become obese, can affect the craniofacial features of obese OSA patients.Methods: The prospective sample consisted of 39 obese and 43 non-obese OSA adults matched for age and OSA severity from a retrospective cohort. The age of obesity onset was determined through a questionnaire and diagnosis of craniofacial and airway morphology was made from standard cephalometric radiographs.Result: Twelve early obese, 21 late obese and 29 non-obese OSA patients were deemed eligible for this study. The mean age was 45.6, 50.9 and 48.1 years for early, late and non-obese groups, respectively. Non-obese OSA, compared to obese subjects, showed a significantly more retrognathic mandible, larger maxillo-mandibular discrepancy, shorter lower facial height, deeper overbite, less upper incisors proclination and protrusion, longer soft palate, higher position of hyoid bone, narrower inferior airway space, longer airway length and less obtuse head posture. The early obesity group, compared to non-obese, showed a prognathic mandible, longer lower facial height, more proclined upper incisors, caudally positioned hyoid bone, wider inferior airway space and shorter airway length. The late obesity group, compared to non-obese group, showed a proclined and protrusive upper incisors, shallower overbite, inferiorly positioned hyoid bone, shorter airway length and obtuse cranio-cervical angle. There was no significant difference between early and late obesity groups. Conclusion: Obese OSA patients have more developed craniofacial skeletons with less bony and airway constriction than their non-obese counterparts; and early and late obesity groups showed discrepancies in their characteristics which were different from non-obese subjects, suggesting a possible impact of obesity onset on craniofacial characteristics. Further studies are still needed to determine the effect of obesity onset on craniofacial development.

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Objectives: Altered dentofacial morphology has been suggested as an etiology for childhood OSA. Nevertheless, existing reports on the dentofacial characteristics of children with OSA vary significantly and are limited by the infrequent use of polysomnography (PSG) for diagnosis. Therefore, the objective of this study is to establish the prevalence of dentofacial morphology in children with OSA diagnosed using PSG.Methods: The sample comprised 64 children between the ages of 4-16 who were referred to BC Children’s Hospital for PSG. Diagnosis of OSA was provided by an overnight, in-laboratory PSG. Malocclusion was assessed clinically by one orthodontist (K.L.), blinded to PSG results. Results: Children with previous orthodontic treatment were excluded and children with craniofacial syndromes were analyzed separately. The 17 patients with craniofacial syndromes presented a significantly different dentofacial features and higher prevalence of OSA when compared to the non-syndromic children. The remaining 39 patients were divided into an OSA group (AHI ≥ 2; n=17) and a non-OSA group (AHI 2; n=22). There were no statistically significant differences in frequency of any dentofacial features between the two groups, although the OSA group had a lower prevalence of convex profile, Class II molar relationship, and overjet (OJ) ≥ 5mm. Subjects in the OSA group were further divided into a lower AHI (AHI between 2-5; n=9) group and a higher AHI group (AHI ≥ 5; n=8). There was no statistically significant difference in frequency of any dentofacial features between the three groups. Nevertheless, subjects in the higher AHI group had a lower prevalence of convex profile and poster crossbite, with less crowding and smaller OJ on average. Conclusions: In this patient population of 39 children between the ages of 4-16 who were referred to BCCH for an overnight sleep study, no statistically significant differences in dentofacial morphology and occlusal characteristics were found between children diagnosed with and without OSA. It is likely that children with OSA have a highly variable presentation of anatomical features, and future studies with a larger sample size and a true control group is needed to establish the dentofacial morphology of this population.

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Objective: The aim of this study was to evaluate the accuracy of three thermosensitive microsensors, which record “wear-time” of removable oral appliances (OA) used for orthodontics and obstructive sleep apnea therapy.Methods: In vitro testing was undertaken for TheraMon (Sensor T, n=20), AIR-AID SLEEP (Sensor A, n=30) and DentiTrac (Sensor D, n=16) microsensors, which were placed in a water bath to simulate “wear-time” of OA. Logs of when the microsensors were placed in the water bath were compared to the time readouts from the microsensors. Trial 1 examined the accuracy of long durations of “wear” (7 hours/day). Trial 2 examined short durations of “wear” (2 hour intervals). Trial 3 tested the impact of different embedding materials on accuracy: acrylic, polyvinylchloride and thermoactive acrylic. In vivo testing included 14 volunteers who wore maxillary retainers embedded with Sensor A and D for 30 nights. Subjects’ logs of appliance usage were compared to the computed readouts from the sensors. Results: In the in vitro phase, the median absolute deviation of the computed “wear-time” minus the logged time was 0.00 minutes for Sensor A and Sensor T in all trials. For Sensor D, the median deviation was 5.00 minutes in trial 1 and 3 and 10.00 minutes in trial 2. Sensor A was significantly more accurate than Sensor T and Sensor D in trial 1 (p0.001). In trial 2, Sensor A and Sensor T were equal in accuracy but were significantly better than Sensor D (p0.001). In trial 3, there was no effect of the material on the recording accuracies of Sensor A (p=0.13) and Sensor D (p=0.41); Polyvinylchloride was found to be significantly less accurate for Sensor T (p0.05). In the in vivo phase, the median absolute deviation of Sensor A was 3.00 minutes and Sensor D was 5.00 minutes; there was no significant difference between Sensor A and Sensor D (p=0.45). Conclusion: Sensor D tended to have the largest deviation in recording accuracy in in vitro testing using the water bath. All three microsensors have acceptable clinical accuracy and can be used to record “wear-time” of removable OA fabricated from different materials.

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