Craniofacial structure and obstructive sleep apnea syndrome--a qualitative analysis and meta-analysis of the literature

Craniofacial anatomical determinants of pediatric sleep-disordered breathing: A comprehensive review

PURPOSE

This narrative review aims to elucidate the anatomical features of sleep-disordered breathing (SDB) in children. By identifying key structures and intervening proactively, we seek to alter craniofacial growth patterns and improve functional outcomes for SDB children.

METHODS

The literature on pediatric sleep-disordered breathing (PSDB), pediatric obstructive sleep apnea (OSA), anatomical predispositions, and the relationship between skeletal deformity and PSDB was examined using PubMed and Google Scholar databases, covering studies from 2006 to 2024.

RESULTS

Forty relevant articles were reviewed, focusing on craniofacial characteristics associated with PSDB. The etiology of PSDB is multifactorial, with adenoid and palatal tonsil enlargement being the most common cause. While adenotonsillectomy is recommended as the primary treatment, residual SDB may result in craniofacial skeletal deformities contributing to upper airway constriction. Typical craniofacial phenotypes of SDB include excessive vertical growth and constriction of the maxilla, a retruded mandible, and posterior rotation, known as a Class II hyperdivergent pattern. Conversely, Class III with an underdeveloped maxilla shows a relatively lower risk for SDB due to reduced nasal cavity and nasopharyngeal airway volumes. Transverse maxillary constriction with a high, deep palatal vault is a significant risk factor. Additionally, nasal obstruction and low tongue posture, with or without a short lingual frenulum, are identified as craniofacial risk factors for SDB development in children.

CONCLUSION

Early diagnosis and intervention are critical in managing PSDB. Dentists, through screening and early treatment, can significantly influence craniofacial growth and health outcomes. A multidisciplinary approach is essential for effective management, improving the quality of life and long-term health of affected children.

A Comprehensive Analysis of the Interrelationship Between Craniofacial Variables in Cephalometric Analysis and Obstructive Sleep Apnea (OSA)

Background/Objectives: Obstructive sleep apnea syndrome (OSAS) is a global condition usually associated with poor health. While common, it appears underdiagnosed due to repeated episodes of upper airway obstruction during the sleep cycle. It is accompanied by other health risks like cardiovascular issues and conditions. Identifying craniofacial characteristics linked to OSAS may enhance diagnostic precision and treatment planning. The aim of our study was to examine the relationship between cephalometric variables and OSAS and determine whether craniofacial features influence the syndrome's development and severity. Methods: Thirty participants were split into two groups: 15 diagnosed with OSAS and 15 controls. Cephalometric evaluations were performed using standardized lateral imaging, with craniofacial, dental, and hyoid bone parameters assessed. Statistical analysis compared these variables between groups to identify significant differences. Results: OSAS patients exhibited significantly shorter maxillary and mandibular lengths, increased anterior facial height, and reduced posterior facial height compared to controls. Dental analysis revealed reduced interincisal angles and lower mandibular incisor positions in the OSAS group. The hyoid bone was positioned lower and more posteriorly in OSAS patients, with significant differences in its distance to the C3 vertebra and mandibular plane. Although the soft palate dimensions were larger in OSAS patients, the differences were not statistically significant. Conclusions: OSAS is associated with distinct craniofacial features, including shorter maxillary and mandibular lengths, altered facial height proportions, and lower hyoid bone positioning. These findings suggest that craniofacial morphology plays a significant role in OSAS pathophysiology. Future studies hinting at three-dimensional imaging could provide deeper insights into these associations.

Craniofacial Development Characteristics in Children with Obstructive Sleep Apnea for Establishment and External Validation of the Prediction Model

Purpose

Aimed to analyze the developmental characteristics of craniofacial structures and soft tissues in children with obstructive sleep apnea (OSA) and to establish and evaluate prediction model.

Methods

It's a retrospective study comprising 747 children aged 2-12 years (337 patients and 410 controls) visited the Department of Otolaryngology-Head and Neck Surgery, the Second Affiliated Hospital of Xi'an Jiaotong University (July 2017 to March 2024). Lateral head radiographs were obtained to compare the cephalometric measurements. The clinical prediction model was constructed using LASSO regression analysis. We analyzed 300 children from the Xi'an Children's Hospital for external validation.

Results

Children with OSA had a higher body mass, a higher tonsil grade, larger AN ratio (ratio of the adenoids to the skeletal upper airway width), larger radius of the tonsils, a smaller angle between the skull base and maxilla (SNA) and smaller angle between the skull base and mandible (SNB), a larger distance from the hyoid to the mandibular plane (H-MP) and smaller distance between the third cervical vertebra and hyoid (H-C), a larger thickness of the soft palate (SPT) and smaller inclination angle of the soft palate than those of the controls (all p < 0.05). A prediction model was constructed for 2-12 years group (AUC of 0.812 [95% CI: 0.781-0.842]). Age-specific prediction models were developed for preschool children (AUC of 0.769 [95% CI: 0.725-0.814]), for school-aged children (AUC of 0.854 [95% CI: 0.812-0.895]).

Conclusion

Our study findings support the important role of craniofacial structures such as the hyoid, maxilla, mandible, and soft palate in pediatric OSA. Age-stratified predictive models for pediatric OSA indicated varying parameters across different age groups which underscore the necessity for stratifying by age in future research. The prediction model designed will greatly assist health care practitioners with rapidly identifying.

Relationship between Cephalometric and Ultrasonic Airway Parameters in Adults with High Risk of Obstructive Sleep Apnea

Background/Objectives: Polysomnography and cephalometry have been used for studying obstructive sleep apnea (OSA) etiology. The association between craniofacial skeleton and OSA severity remains controversial. To study OSA's etiology, cephalometry, fiberoptic pharyngoscopy, polysomnography, and sleep endoscopy have been used; however, airway obstructions cannot be located. Recent research suggested ultrasonography for OSA screening and upper airway obstruction localization. Thus, this study aims to investigate the relationship between specific craniofacial cephalometric and ultrasonic airway parameters in adults at high risk of OSA. Methods: To assess craniofacial structure, lateral cephalograms were taken from thirty-three adults over 18 with a STOP-Bang questionnaire score of three or higher and a waist-to-height ratio (WHtR) of 0.5 or higher. Airway parameters were assessed through submental ultrasound. Results: NSBA correlated with tongue base airspace width, while MP-H correlated with oropharynx, tongue base, and epiglottis airspace width. SNA, SNB, and NSBA correlated with tongue width at the oropharynx. At tongue base, ANB and MP-H correlated with tongue width. SNB and NSBA were associated with deep tissue thickness at the oropharynx, while MP-H correlated with superficial tissue thickness at velum and oropharynx. Conclusions: Cephalometric parameters (SNA, SNB, ANB, NSBA, and MP-H) were correlated with ultrasonic parameters in the velum, oropharynx, tongue base, and epiglottis.

Cephalometric Screening Assessment for Superior Airway Space Narrowing-Added Value of Three-Dimensional Imaging

Background: Assessing the morphology of the superior airway space is a crucial diagnostic step in the treatment planning of patients with obstructive sleep apnea syndrome (OSAS) or prior to orthognathic surgery. The aim of this study is to evaluate the necessary scope of a two-dimensional cephalometric assessment and the necessity of three-dimensional imaging in the identification of superior airway space narrowing (SASN). Methods: The computed tomography studies of 100 non-obese, non-OSAS patients were evaluated and analyzed retrospectively. Multiplanar reconstructions were created and underwent cephalometric evaluation. The three-dimensional superior airway morphology was segmented and measured for the minimal cross-sectional area (Amin) and volume (V0). Patients were grouped according to Amin < 80 mm2 and V0 < 12 cm3. Cephalometric parameters (CPs) were analyzed according to Amin and V0 with an unpaired t-test, Pearson correlation, and ROC-curve analysis. Results: The CPs regarding sagittal airway space dimensions (IPAS, MPAS, SPAS) and mandibular body length (GoGn) show the strongest correlation to the three-dimensional minimal cross-sectional area (Amin). The ROC-curve analysis classifying for SASN led to an AUC of 0.86 for IPAS, 0.87 for MPAS, 0.88 for SPAS, and 0.63 for GoGn. Three-dimensional imaging may further improve the diagnostic accuracy in the identification of SASN for IPAS below 13.5 mm, MPAS below 10.2 mm, SPAS below 12.5 mm, and GoGn below 90.2 mm. Conclusions: Two-dimensional cephalometric sagittal airway space diameters and mandibular body length are useful initial screening parameters in the identification of superior airway space narrowing. Nevertheless, as the correlation of two-dimensional cephalometric parameters with three-dimensional upper airway space narrowing is varying and highly dependent on acquisition circumstances, indications for three-dimensional imaging, if possible, in the supine position to evaluate upper airway space morphology should be provided generously, especially in patients with low but normal airway space parameters in two-dimensional cephalometry.

Sleepiness in children with severe malocclusion compared with in children with neutral occlusion

INTRODUCTION

The study aimed to compare daytime sleepiness in children with severe malocclusion with healthy children with neutral occlusion (controls) and to analyze associations between daytime sleepiness and craniofacial morphology in children with severe malocclusion.

METHODS

In 120 children with severe malocclusion (73 girls, 47 boys; mean age, 11.96 years; mean body mass index [BMI] score, 18.97 kg/m2) and 35 controls (18 girls, 17 boys; mean age, 11.97 years; mean BMI score, 20.28 kg/m2), sleep and daytime sleepiness were recorded using Epworth Sleepiness Scale and Berlin Questionnaire. Occlusion was registered clinically, and craniofacial morphology was assessed on lateral cephalograms. Differences in daytime sleepiness and sleep between the groups and associations between daytime sleepiness and sleep and craniofacial morphology were analyzed by a general linear model adjusted for age, gender, and BMI score.

RESULTS

Daytime sleepiness occurred significantly more often in children with malocclusion than in control subjects (P = 0.015). There was a tendency for children with malocclusion to feel extremely tired during the day more often than controls (P = 0.054). There was no significant difference between the groups in sleeping hours during night-time, but the amount of sleep was negatively associated with age (P <0.001) and BMI score (P = 0.004). Only maxillary inclination was significantly associated with daytime sleepiness (P = 0.043).

CONCLUSIONS

Daytime sleepiness occurred significantly more often in children with severe malocclusion than in those with neutral occlusion, and the association between daytime sleepiness and craniofacial morphology may exist. The results might prove valuable in interdisciplinary collaboration between medical doctors and orthodontists in diagnostics, prevention, and treatment of children at risk for sleep-disordered breathing.

Obstructive sleep apnea detection during wakefulness: a comprehensive methodological review

Obstructive sleep apnea (OSA) is a chronic condition affecting up to 1 billion people, globally. Despite this spread, OSA is still thought to be underdiagnosed. Lack of diagnosis is largely attributed to the high cost, resource-intensive, and time-consuming nature of existing diagnostic technologies during sleep. As individuals with OSA do not show many symptoms other than daytime sleepiness, predicting OSA while the individual is awake (wakefulness) is quite challenging. However, research especially in the last decade has shown promising results for quick and accurate methodologies to predict OSA during wakefulness. Furthermore, advances in machine learning algorithms offer new ways to analyze the measured data with more precision. With a widening research outlook, the present review compares methodologies for OSA screening during wakefulness, and recommendations are made for avenues of future research and study designs.

Exploring long-term changes and influencing factors of the upper airway in patients with a skeletal Class II relationship after mandibular advancement with maxillary setback surgery: A comprehensive 2-year follow-up investigation

INTRODUCTION

The objective of this study was to investigate the 2-year postoperative change and influencing factors of the upper airway after mandibular advancement with maxillary setback surgery for patients with a skeletal Class II relationship.

METHODS

Fifty-seven participants who underwent mandibular advancement with maxillary setback surgery were enrolled consecutively. Cone-beam computed tomography was performed preoperatively, 3 months postoperatively (T1), and 2 years (T2) postoperatively. All parameters were measured using Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif).

RESULTS

The total volume (V), minimum cross-sectional area (CSAmin), and glossopharynx increased significantly in both the short-term (V, 13.33%; CSAmin, 33.03%; glossopharynx, 26.73%) and long-term (V, 10.19%; CSAmin, 23.18%; glossopharynx, 18.27%) after the surgery. Mandibular advancement, mandibular width increase, preoperative CSAmin, and body mass index (BMI) significantly affected 2-year postoperative V increases. Mandibular advancement and BMI significantly affected 2-year postoperative glossopharynx increases. Backward movement of point PNS may lead to a reduction of the nasopharynx; however, downward movement of point PNS, upward movement of point A, and increased maxillary width may compensate for this effect by increasing the likelihood of the nasopharynx opening. Furthermore, mandibular body length at T1 is positively associated with relapse rate ([T2 - T1] / T1) of V and CSAmin.

CONCLUSIONS

Mandibular advancement amount, mandibular width increase, preoperative CSAmin, and BMI are the 4 factors for long-term V changes. Patients with a longer mandibular body length might have a lower relapse rate.

Cephalometric Evaluation in Patients with Obstructive Sleep Apnea undergoing Lateral Pharyngoplasty

Introduction  Lateral pharyngoplasty (LP) has shown promising results. Craniofacial deformity reduces the pharyngeal space, contributing to the etiopathogenesis. The analysis of craniofacial features can be performed using cephalometry. Objective  To verify if craniofacial deformity is associated with worse polysomnographic data in patients with obstructive sleep apnea (OSA), and to verify if the preoperative cephalometric parameters can interfere with the surgical success of the LP. Methods  The study included 21 patients with OSA aged between 18 and 65 years who underwent LP in a university hospital from 2015 to 2019. Polysomnography was performed postoperatively, after a minimum period of 6 months from the surgical procedure. In addition, a cephalometric evaluation was performed to assess craniofacial deformity, and to correlate it with the polysomnographic results. Results  The mean and median of all polysomnographic respiratory parameters improved postoperatively, especially the apnea-hypopnea index (AHI), which went from 40.15 to 16.60 events per hour ( p  = 0.001). Of the 21 patients, 15 showed improvements in the AHI postoperatively. As for the cephalometric evaluations, we found that the longer the distance between the hyoid bone and the mandibular plane, the greater the patient's preoperative AHI ( p  = 0.011). When assessing whether cephalometric changes related to craniofacial deformities influence the surgical outcome of LP, no correlation was found for any cephalometric measurement. Conclusion  The longer the distance between the hyoid bone and the mandibular plane, the greater the preoperative AHI, and LP was an effective OSA treatment. Cephalometric variables are not able to modify or determine the success of LP in apneic patients in the population assessed.

Craniofacial risk factors for obstructive sleep apnea-systematic review and meta-analysis

Obstructive sleep apnea (OSA) is caused by temporary partial or complete constriction of the upper airway during sleep which leads to reduced blood oxygen and cardiovascular risks. Main symptoms vary between adults and children leading to misdiagnosis or delayed patient identification. To improve early diagnosis, lateral cephalograms can provide craniofacial measurements associated with a higher risk of OSA. In order to identify the most relevant craniofacial measurements, a systematic literature review with meta-analysis was conducted combining the terms 'orthodontic*', 'craniofacial', 'cephalometr*', 'cephalogram', 'OSA*', 'UARS', 'SDB', 'sleep disordered breathing', 'sleep apnea' and 'sleep apnoea'. Of 3016 publications, 19 were included in the systematic review and meta-analysis, 15 with adult patients and four with children. A total of 16 measurements (six angles, 10 distances) were compared, nine showed a possible influence in patients with OSA compared to controls: NSBa angle (-0.28°), ANB angle (+0.33°), ML-NSL angle (+0.34°), Me-Go-Ar angle (+0.33°), SN distance (-0.70 mm), N-ANS distance (-0.36 mm), MP-H distance (+1.18 mm), uvula length (+1.07 mm) and thickness (+0.96 mm). Posterior airway measurements were not sufficiently described or comparably measured to be statistically analysed. There is some evidence for altered craniofacial anatomy in patients with OSA compared to controls. Lateral cephalograms should be screened for these aspects routinely to improve early diagnosis of OSA and craniofacial orthopaedics should complement the interdisciplinary treatment plan for young patients with OSA.

Does orthognathic surgery have an incidentally beneficial effect on mild or asymptomatic sleep apnoea?

A prospective study was performed to assess the effect of orthognathic surgery on mild obstructive sleep apnoea (OSA) in patients with an underlying dentofacial deformity treated for occlusal and/or aesthetic reasons. As the main outcome variables, changes in upper airway volume and apnoea-hypopnoea index (AHI) were evaluated at 1 and 12 months of follow-up, in patients undergoing orthognathic surgery with widening movements of the maxillomandibular complex. Descriptive, bivariate, and correlation analyses were performed; significance was set at P < 0.05. Eighteen patients diagnosed with mild OSA were enroled (mean age 39.8 ± 10.0 years). An overall upper airway volume widening of 46.7% after orthognathic surgery was observed at 12 months of follow-up. The AHI decreased significantly from a median 7.7 events/hour preoperatively to 5.0 events/h at 12 months postoperative (P = 0.045), and the Epworth Sleepiness Scale score decreased from a median 9.5 preoperatively to 7 at 12 months postoperative (P = 0.009). A cure rate of 50% was obtained at 12 months of follow-up (P = 0.009). Despite the limited sample size, this study provides evidence that in patients with an underlying retrusive dentofacial deformity and mild OSA, a slight decrease in AHI is obtained after orthognathic surgery due to upper airway enlargement, which could be added as a beneficial effect of orthognathic surgery.

The Impact of Clinical and Craniofacial Changes on the Surgical Outcomes of Lateral Pharyngoplasty in the Treatment of Obstructive Sleep Apnea

Objective  To verify if maxillomandibular retrusion, obesity, and increased neck circumference are factors of worse surgical prognosis for lateral pharyngoplasty in apneic patients. Materials and Methods  We evaluated 53 patients with obstructive sleep apnea who underwent lateral pharyngoplasty. Clinical evaluation was performed before the surgical procedure and included the measurement of body mass index (BMI) in kg/m 2 , neck circumference in centimeters, and a clinical evaluation of the facial profile obtained through the natural position of the oriented head. The polysomnographic evaluation was performed with at a minimum of 6 months after surgery, and polysomnographic results were correlated with the preoperative clinical data. Results  The mean age of the patients was 38.8 years; the mean BMI was of 29.28kg/m 2 , and 84.9% of the sample was composed of men and 15.1% of women. There was a significant reduction in the mean value of the main respiratory parameters verified by polysomnography, such as apnea-hypopnea index (AHI) from 31.60 events per hour to 8.15 ( p  < 0.001); NadirO 2 went from 81% to 85% ( p  = 0.002) and mean oxyhemoglobin saturation from 94% to 95% ( p  = 0.024). It was also observed that the greater the maxillomandibular retrusion, the lower the mean reduction of the AHI after surgery. The increase in neck circumference proved to be a factor associated with the surgical outcome, and for each 1-cm decrease in the neck circumference, the chance of surgical success increased 1.2-fold. Conclusion  Lateral pharyngoplasty is an efficient surgical obstructive sleep apnea treatment. The lower the neck circumference measurement, the greater the chances of surgical success, and clinically evaluated maxillomandibular retrusion can reduce the magnitude of improvement in respiratory parameters after lateral pharyngoplasty in apneic patients.

Facial Contour Features Measured on CT Reflects Upper Airway Morphology in Patients With OSA

OBJECTIVE

To determine facial contour features, measured on computed tomography (CT), related to upper airway morphology in patients with obstructive sleep apnea (OSA); certain phenotype of facial abnormalities implying restriction of craniofacial skeleton and adipose tissue nimiety has predicted the value of the severity of OSA.

MATERIALS AND METHOD

Sixty-four male patients with OSA [apnea-hypopnea index (AHI) ≥10/h] who had upper airway CT were randomly selected to quantitatively measure indicators of facial contour and upper airway structures. Pearson correlation analyses were performed. Partial correlation procedure was used to examine correlations while controlling body mass index (BMI).

RESULTS

Upper airway anatomy can nearly all be reflected in the face, except retroglossal airway. Upper face width can be measured to assess the overall skeletal structures of the airway. Lower face width can be used to represent how much adipose tissue deposited. Hard palate, retropalatal, and hypopharyngeal airways have corresponding face indicators respectively. Midface width is a better predictor of AHI severity and minimum blood oxygen even than neck circumference because it contains the most anatomical information about the airway, including RP airway condition, soft palate length, tongue volume, etc. These correlations persisted even after correction for BMI.

CONCLUSIONS

All anatomical features of the upper airway except retroglossal airway can be reflected in the face, and midface width is the best predictor of AHI severity and minimum blood oxygen, even better than neck circumference and BMI.

Three-dimensional evaluation of the association between tongue position and upper airway morphology in adults: A cross-sectional study

Objective

This study aimed to evaluate the association between low tongue position (LTP) and the volume and dimensions of the nasopharyngeal, retropalatal, retroglossal, and hypopharyngeal segments of the upper airway.

Methods

A total of 194 subjects, including 91 males and 103 females were divided into a resting tongue position (RTP) group and a LTP group according to their tongue position. Subjects in the LTP group were divided into four subgroups (Q1, Q2, Q3, and Q4) according to the intraoral space volume. The 3D slicer software was used to measure the volume and minimum and average cross-sectional areas of each group. Airway differences between the RTP and LTP groups were analyzed to explore the association between tongue position and the upper airway.

Results

No significant differences were found in the airway dimensions between the RTP and LTP groups. For both retropalatal and retroglossal segments, the volume and average cross-sectional area were significantly greater in the patients with extremely low tongue position. Regression analysis showed that the retroglossal airway dimensions were positively correlated with the intraoral space volume and negatively correlated with A point-nasion-B point and palatal plane to mandibular plane. Males generally had larger retroglossal and hypopharyngeal airways than females.

Conclusions

Tongue position did not significantly influence upper airway volume or dimensions, except in the extremely LTP subgroup.

Correlation analysis of upper airway morphology in patients with obstructive sleep apnea and anatomically small retruded mandibles

OBJECTIVE

To investigate the relationship between upper airway morphology and the severity of obstructive sleep apnea (OSA) in patients with anatomically small retruded mandibles.

METHODS

Fifty-two patients with small retruded mandibles underwent polysomnography and airway computed tomography. The airway morphology parameters and sleep assessment were compared between the patients with or without OSA.

RESULTS

Twenty-eight patients diagnosed with OSA, according to polysomnography, had a higher distance between the hyoid bone and mandibular plane (HMP), lateral dimension (LAT)/anteroposterior dimension (AP), but lower minimum cross-sectional area (mCSA), AP, surface area, volume, avgCSA, and airway uniformity (U). The apnea-hypopnea index had negative correlations with mCSA, AP, surface area, volume, avgCSA, and U, and had a positive correlation with HMP and LAT/AP.

CONCLUSION

OSA is common among patients with small retruded mandibles and is associated with a more compressed upper airway shape and longer HMP.

Insights into the Use of Point-of-Care Ultrasound for Diagnosing Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a sleeping disorder caused by complete or partial disturbance of breathing during the night. Existing screening methods include questionnaire-based evaluations which are time-consuming, vary in specificity, and are not globally adopted. Point-of-care ultrasound (PoCUS), on the other hand, is a painless, inexpensive, portable, and useful tool that has already been introduced for the evaluation of upper airways by anesthetists. PoCUS could also serve as a potential screening tool for the diagnosis of OSA by measuring different airway parameters, including retropalatal pharynx transverse diameter, tongue base thickness, distance between lingual arteries, lateral parapharyngeal wall thickness, palatine tonsil volume, and some non-airway parameters like carotid intima-media thickness, mesenteric fat thickness, and diaphragm characteristics. This study reviewed previously reported studies to highlight the importance of PoCUS as a potential screening tool for OSA.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Role of craniofacial phenotypes in the response to oral appliance therapy for obstructive sleep apnea

BACKGROUND

Mandibular advancement device (MAD) is a good alternative for patients with obstructive sleep apnea (OSA). However, the treatment response varies amongst individuals.

OBJECTIVE

This study aimed to explore the role of craniofacial features in the response to MADs to improve prognostication and patient selection.

METHODS

The retrospective trial contained 42 males aged 41.5 ± 9.0 years, and with an apnea-hypopnea index (AHI) of 21.5 ± 13.8 events/h. According to the mandibular plane angle, participants were divided into three groups: low angle (n = 13), average angle (n = 14) and high angle (n = 15). Under the monitoring of home sleep testing, adjustable MADs were used to titrate the mandible forward from 0 mm with an increment of 0.5 mm every day. The polysomnography outcomes, mandibular protrusion amounts, changes in upper airway MRI measurements and nasal resistance were compared amongst the three groups.

RESULTS

The normalisation rate (AHI <5 /h) was 92.3%, 57.1% and 46.7%, respectively, in the low-, average- and high-angle groups (p = .027). The effective protrusion where AHI was reduced by half was 20 (11.3 ~ 37.5) %, 31.3 (23.6 ~ 50) % and 50 (36.9 ~ 64.9) % of the maximal mandibular protrusion, in the low-, average- and high-angle groups (p = .004). Multivariate logistic regression revealed that increased gonion angle (OR = 0.878) and baseline AHI(OR = 0.868) can reduce the probability of normalisation.

CONCLUSION

The high mandibular plane angle might be an unfavourable factor to MAD treatment and more protrusion was needed to achieve a 50% reduction in AHI. Vertical craniofacial pattern (gonion angle) and baseline AHI constituted the model for predicting the effect of MADs.

The changes in oral volume and hyoid bone position after maxillomandibular advancement and genioglossus advancement for patients with obstructive sleep apnea

INTRODUCTION

Maxillomandibular advancement (MMA) and genioglossus advancement (GA) are surgeries for patients with obstructive sleep apnea (OSA). Postoperative evaluation is primarily based on the apnea-hypopnea index (AHI) measured by polysomnography. The purpose of this study was to identify the timing of hyoid bone relocation after MMA and GA surgery and to investigate whether or not hyoid bone relocation can be an indicator of postoperative evaluation of OSA.

METHODS

Patients with OSA underwent MMA and GA surgery. Changes in hyoid bone position and tongue-to-oral volume ratio were analyzed on lateral radiographs before, immediately after, and 1 year after surgery. Then, a correlation was verified between these changes and postoperative AHI.

RESULTS

In 18 patients studied, the position of the hyoid bone did not show a constant tendency immediately after surgery. One year after surgery, the bone had moved anteriorly and toward the oral cavity in all patients compared to its preoperative position. And AHI correlated with the movement of the hyoid bone to the oral side.

DISCUSSION

One year after surgery, the tongue was adapted to the newly enlarged oral space, and as a result, the low position of the hyoid bone before the operation was improved. The findings suggest that the degree of lowering of the hyoid bone may be an indicator of the improvement of AHI.

The dental and craniofacial characteristics among children with obstructive sleep apnoea: a systematic review and meta-analysis

BACKGROUND

Paediatric obstructive sleep apnoea (OSA) is a sleep breathing disorder which may have dramatic effects on childhood behaviour, neurodevelopment, metabolism, and overall health in children. Malocclusion and craniofacial morphology may be related to paediatric OSA, and therefore provide information for clinicians to recognize, evaluate and treat patients with this sleeping disorder.

OBJECTIVE

The aim of this systematic review was to summarize evidence regarding the association between paediatric OSA and children's dental and craniofacial characteristics.

SEARCH METHODS

PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched from inception to 1 June 2022.

SELECTION CRITERIA

Cross-sectional studies, comparing dental or craniofacial characteristics using clinical dental examinations or radiographic findings between OSA children (less than 18 year, diagnosed with overnight polysomnography) and healthy children, were included.

DATA COLLECTION AND ANALYSIS

The Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross-Sectional Studies was used to assess the quality of included studies. RevMan software was used for performing the Meta-analyses.

RESULTS

Sixteen studies were included. Meta-analyses showed that the overjet (MD = 0.86, 95% CI: 0.20 to 1.51; P = 0.01), the saggital skeletal jaw discrepancy (ANB; MD = 1.78, 95% CI: 1.04 to 2.52; P < 0.00001) and mandibular plane angle (FH-MP; MD = 3.65, 95% CI: 2.45 to 4.85; P < 0.00001) were greater in OSA-affected children. In contrast, the upper molar arch width (upper first deciduous molar width; MD = -1.86, 95% CI: -3.52 to -0.20; P = 0.03), (Upper second deciduous molar width; MD = -1.06, 95% CI: -1.88 to -0.24; P = 0.01), SNB (MD = -2.10, 95% CI: -3.11 to -1.09; P < 0.0001), and maxillary length (ANS-PNS; MD = -1.62, 95% CI: -2.66 to -0.58; P = 0.002) were smaller in the OSA group.

CONCLUSIONS

This review shows that OSA-affected children tend to present with mandibular retroposition or retrognathia, increased mandibular plane angle and excess anterior overjet. However, these findings need to be viewed with caution as the corresponding differences may not be significant clinically.

REGISTRATION

PROSPERO (CRD42020162274).

Correlations between Morphology, the Functional Properties of Upper Airways, and the Severity of Sleep Apnea

Obstructive sleep apnea (OSA) is considered the silent killer pathology of the new millennium. This is due to increased risk factors such as obesity. Healthcare systems face an increasing burden from severe cases of OSA. We performed a study on a group of 152 Romanian patients with OSA recording data obtained through polysomnography and cephalometric variables, recorded in lateral plain X-rays. The results confirmed some of the data available from previous studies worldwide, but some of the variables presented a positive statistical correlation specific to our study group. For example, the apnea-hypopnea index (AHI) correlated with the uvula length but surprisingly did not correlate with body mass index (BMI) because obesity tends to become endemic in Romania. To our knowledge, this is one of the first studies focusing on cephalometric data in Romanian OSA patients. The results obtained through this study will be further analyzed in research on larger groups of Romanian OSA patients.

Assessment of the accuracy of imaging software for 3D rendering of the upper airway, usable in orthodontic and craniofacial clinical settings

BACKGROUND

Several semi-automatic software are available for the three-dimensional reconstruction of the airway from DICOM files. The aim of this study was to evaluate the accuracy of the segmentation of the upper airway testing four free source and one commercially available semi-automatic software. A total of 20 cone-beam computed tomography (CBCT) were selected to perform semi-automatic segmentation of the upper airway. The software tested were Invesalius, ITK-Snap, Dolphin 3D, 3D Slicer and Seg3D. The same upper airway models were manually segmented (Mimics software) and set as the gold standard (GS) reference of the investigation. A specific 3D imaging technology was used to perform the superimposition between the upper airway model obtained with semi-automatic software and the GS model, and to perform the surface-to-surface matching analysis. The accuracy of semi-automatic segmentation was evaluated calculating the volumetric mean differences (mean bias and limits of agreement) and the percentage of matching of the upper airway models compared to the manual segmentation (GS). Qualitative assessments were performed using color-coded maps. All data were statistically analyzed for software comparisons.

RESULTS

Statistically significant differences were found in the volumetric dimensions of the upper airway models and in the matching percentage among the tested software (p < 0.001). Invesalius was the most accurate software for 3D rendering of the upper airway (mean bias = 1.54 cm³; matching = 90.05%) followed by ITK-Snap (mean bias =  - 2.52 cm³; matching = 84.44%), Seg 3D (mean bias = 3.21 cm³, matching = 87.36%), 3D Slicer (mean bias =  - 4.77 cm³; matching = 82.08%) and Dolphin 3D (difference mean =  - 6.06 cm³; matching = 78.26%). According to the color-coded map, the dis-matched area was mainly located at the most anterior nasal region of the airway. Volumetric data showed excellent inter-software reliability (GS vs semi-automatic software), with coefficient values ranging from 0.904 to 0.993, confirming proportional equivalence with manual segmentation.

CONCLUSION

Despite the excellent inter-software reliability, different semi-automatic segmentation algorithms could generate different patterns of inaccuracy error (underestimation/overestimation) of the upper airway models. Thus, is unreasonable to expect volumetric agreement among different software packages for the 3D rendering of the upper airway anatomy.

Upper Airway Changes in Diverse Orthodontic Looms: A Systematic Review and Meta-Analysis

Upper airway assessment is particularly important in the daily work of orthodontists, because of its close connection with the development of craniofacial structures and with other pathologies such as Obstructive Sleep Apnea Syndrome (OSAS). Three-dimensional cone-beam computed tomography images provide a more reliable and comprehensive tool for airway assessment and volumetric measurements. However, the association between upper airway dimensions and skeletal malocclusion is unclear. Therefore, the current systematic review evaluates the effects of different surgical movements on the upper airway. Materials and Methods: Medline (PubMed, OVID Medline, and EBSCO), Cochrane Library (Cochrane Review and Trails), Web of Knowledge (social science, and conference abstracts), Embase (European studies, pharmacological literature, and conference abstracts), CINAHL (nursing and allied health), PsycInfo (psychology and psychiatry), SCOPUS (conference abstracts, and scientific web pages), and ERIC (education) databases were searched. Two authors independently performed the literature search, selection, quality assessment, and data extraction. Inclusion criteria encompassed computed tomography evaluations of the upper airway spaces with retrospective, prospective, and randomised clinical trial study designs. To grade the methodological quality of the included studies a GRADE risk of bias tool was used. Results and conclusion: In total, 29 studies were included. Among these, 17 studies had a low risk of bias, whereas 10 studies had a moderate risk of bias. A meta-analysis was performed with the mean differences using a fixed-effects model. Heterogeneity was assessed with the Q-test and the I2 index. The meta-analysis revealed significant (p ≤ 0.001, 95% confidence interval) increases in upper airway volume after rapid maxillary expansion and surgical advancement for the correction of Class II.

Three-dimensional craniofacial characteristics associated with obstructive sleep apnea severity and treatment outcomes

OBJECTIVES

This study aims to assess craniofacial dimensions in obstructive sleep apnea (OSA) patients treated with a mandibular advancement device (MAD) and to identify anatomic influences on OSA severity and MAD therapy outcomes.

MATERIALS AND METHODS

Twenty patients with OSA were prospectively treated with MAD. Clinical, cone-beam computed tomography, and polysomnography exams were performed before treatment and 4-6 months after achieving the MAD therapeutic position. Polysomnographic exams and three-dimensional maxillary, mandibular, and upper airway (UA) measurements were evaluated. Pearson's correlation and t-tests were applied.

RESULTS

Before MAD treatment, the transverse width measured at the frontomaxillary suture and the angle between the mandibular ramus and Frankfurt horizontal were statistically correlated with apnea and the hypopnea index (AHI), while the gonial angle was correlated with therapeutic protrusion. After MAD treatment, all patients showed a significant AHI reduction and an improvement in minimum oxyhemoglobin saturation. The UA total volume, superior and inferior oropharynx volume, and area were statistically correlated with MAD therapeutic protrusion. The UA total area showed a statistical correlation with the improvement in AHI, and the superior oropharynx volume and area increased significantly.

CONCLUSIONS

The transversal frontomaxillary suture width and the mandibular ramus facial angle may influence OSA severity. The gonial angle, volume, and area of all UA regions may indicate the amount of protrusion needed for successful MAD treatment.

CLINICAL RELEVANCE

The craniofacial characteristics reported as important factors for OSA severity and MAD treatment outcomes impact therapy planning for OSA patients, considering individual anatomic characteristics, prognosis, and cost benefits.

Association of sleep disturbances and craniofacial characteristics in children with class ii malocclusion: An evaluative study

Background

Behaviour problems, poor academic performance and failure to thrive are some of the potential sequelae of sleep problems in children. Hence, there is a need to evaluate the prevalence of sleep problems and significant associations in children with skeletal class II malocclusion with mandibular retrognathism.

Aims

This study aimed to determine associations if any between sleep practices and problems and craniofacial characteristics in children with skeletal class II malocclusion with mandibular deficiency.

Settings and Design

A cross-sectional study was conducted among a group of children with skeletal class II malocclusion with mandibular retrognathism.

Materials and Methods

Fifty children aged 8-14 years with skeletal class II with mandibular retrognathism and who required myofunctional therapy were selected. A validated sleep questionnaire assessed the sleep practices and problems. A detailed clinical examination including tonsils and evaluation for mouth breathing was performed. A lateral cephalogram recorded specific linear, angular variables as well as upper and lower pharyngeal airway space.

Statistical Analysis

Descriptive statistics, frequency, and percentages were calculated, and the Chi-square test was used.

Results

All children reported at least one sleep problem, with snoring reported by 76% of the children. Forty-two percent of the children showed a decreased upper airway, whereas 80% showed a decreased lower airway. Significant associations were seen between SN-MP and noisy breathing, upper airway, and snoring with a P value of 0.017. We also found significant associations between upper and lower airway and sleep positions with a P value of 0.021 and 0.005, respectively.

Conclusion

All the children exhibited at least one sleep problem. There was a strong association of certain sleep practices and sleep problems with cephalometric variables.

Effectiveness of Continuous Positive Airway Pressure Versus Mandibular Advancement Device in Severe Obstructive Sleep Apnea Patients With Mandibular Retrognathia: A Prospective Clinical Trial

AIM

Some obstructive sleep apnea (OSA) patients may have mandibular retrognathia (ANB > 4.7° and SNB < 76.2°). Currently, there are no studies that have compared the effectiveness of continuous positive airway pressure (CPAP) versus mandibular advancement device (MAD) in severe OSA patients with mandibular retrognathia. We explored the efficacy of CPAP versus MAD for the treatment of severe OSA patients with mandibular retrognathia.

METHODS

A total of 105 patients were enrolled. Outcomes were assessed by using polysomnography, Epworth Sleepiness Scale (ESS), Snore Scale (SS), Self-rating Anxiety Scale (SAS), and compliance, before treatment and after 6 and 12 months of treatment.

RESULTS

Continuous positive airway pressure was superior to MAD in improving polysomnographic outcomes and SS score, but reported compliance was higher on MAD. There is no significant difference between the 2 treatments in terms of ESS score and SAS score. Obstructive sleep apnea patients with mandibular retrognathia showed greater improvement than those without mandibular retrognathia in terms of apnea-hypopnea index and oxygen desaturation index after MAD.

CONCLUSION

Continuous positive airway pressure and MAD are both effective in treating severe OSA patients with mandibular retrognathia. Mandibular advancement device is a good alternative to CPAP in severe OSA patients with mandibular retrognathia. Mandibular advancement device is more effective in treating OSA patients with mandibular retrognathia than those without. Trial registration: ChiCTR2000032541.

Upper airway morphological changes in obstructive sleep apnoea: effect of age on pharyngeal anatomy

OBJECTIVE

To evaluate the upper airway morphology changes associated with ageing in adult Chinese patients with obstructive sleep apnoea.

METHODS

A total of 124 male patients diagnosed with obstructive sleep apnoea by overnight polysomnography, who underwent upper airway computed tomography, were enrolled. The linear dimensions, cross-sectional area and volume of the upper airway region and the surrounding bony frame were measured. The association between ageing and upper airway morphology was analysed.

RESULTS

Soft palate length, minimum cross-sectional area of the retroglossal region, lateral dimensions at the minimum cross-sectional area of the retropalatal and retroglossal regions, nasopharyngeal volume, and average cross-sectional area of the nasopharyngeal region were found to significantly increase with ageing in all patients, while the upper airway shape flattened with ageing. The volume of the retropalatal region increased with ageing among the patients with a body mass index of less than 24 kg/m2. The volume of parapharyngeal fat pad increased with ageing among patients with a body mass index greater than 28 kg/m2.

CONCLUSION

A number of dimensional, cross-sectional and volumetric parameters of the pharynx increased with age, indicating that non-anatomical factors may play a more important role in the pathogenesis of obstructive sleep apnoea in aged patients.

Clustering-based characterization of clinical phenotypes in obstructive sleep apnoea using severity, obesity, and craniofacial pattern

OBJECTIVES

To identify and characterize the phenotypes of adult obstructive sleep apnoea (OSA) patients based on clustering using OSA severity, obesity, and craniofacial pattern.

MATERIAL AND METHODS

The samples consisted of 89 adult OSA patients whose polysomnography and lateral cephalogram were available. With cluster analysis using apneahypopnea index (AHI, events/hour), body mass index (BMI, kg/m2), ANB (degree), and mandibular plane angle (MPA, degree), three clusters were identified. Cephalometric variables including craniofacial, soft palate, hyoid bone, and pharyngeal space compartments were compared among clusters by one-way analysis of variance or Kruskal-Wallis test. Multivariable linear regression analysis was performed to find contributing factors to OSA severity within each cluster.

RESULTS

Cluster-1 (obesity type; 49.4 per cent) exhibited moderate OSA, obesity, and normal sagittal and vertical skeletal pattern (AHI, 22.4; BMI, 25.5; ANB, 3.2 degrees; MPA, 26.3 degrees) without significant upper airway abnormality. Cluster-2 (skeletal type; 33.7 per cent) was characterized by moderate OSA, severe skeletal Class II hyperdivergent pattern with narrow pharyngeal airway spaces, without obesity (AHI, 27.9; BMI, 23.5; ANB, 7.5 degrees; MPA, 36.6 degrees). Cluster-3 (complex type; 16.8 per cent) included severe OSA, obesity, skeletal Class II hyperdivergent pattern (AHI, 52.8; BMI, 28.0; ANB, 4.5 degrees; MPA, 32.2 degrees), with posteriorly displaced hyoid and retroclined soft palate. The main contributing factors to AHI were obesity in Cluster-1; hyperdivergent vertical pattern with narrow pharyngeal space in Cluster-2; and hyperdivergent pattern, obesity, displaced hyoid, and soft palate in Cluster-3.

CONCLUSION

Three OSA phenotypes resulted from this study provide a clinical guideline for differential diagnosis and orthodontic intervention in the interdisciplinary treatment for OSA patients.

The Role of Animal Models in Developing Pharmacotherapy for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a highly prevalent disease characterized by recurrent closure of the upper airway during sleep. It has a complex pathophysiology involving four main phenotypes. An abnormal upper airway anatomy is the key factor that predisposes to sleep-related collapse of the pharynx, but it may not be sufficient for OSA development. Non-anatomical traits, including (1) a compromised neuromuscular response of the upper airway to obstruction, (2) an unstable respiratory control (high loop gain), and (3) a low arousal threshold, predict the development of OSA in association with anatomical abnormalities. Current therapies for OSA, such as continuous positive airway pressure (CPAP) and oral appliances, have poor adherence or variable efficacy among patients. The search for novel therapeutic approaches for OSA, including pharmacological agents, has been pursued over the past years. New insights into OSA pharmacotherapy have been provided by preclinical studies, which highlight the importance of appropriate use of animal models of OSA, their applicability, and limitations. In the present review, we discuss potential pharmacological targets for OSA discovered using animal models.

Obstructive sleep apnea severity and dental arches dimensions in children with late primary dentition: An observational study

Objective: The aim of this study was to compare the dimensions of the upper and lower arches in children affected by OSAS with different levels of severity of obstruction.Methods: Twenty-seven Caucasian children (14 males, 13 females; mean age 6, range 5.2-6.1 years) with a diagnosis of OSAS determined by polysomnography were enrolled in this study. The dimensions of both dental arches were measured, and the data were compared among children affected by severe, moderate, and mild OSAS.Results: Statistically significant differences among the three groups revealed that children with severe OSAS had the highest values of upper intercanine and intermolar distances in the sample.Discussion: A severe OSAS grade (AHI > 10) is associated with statistically significantly higher upper intercanine and intermolar distances compared with mild and moderate grades. An early approach to OSAS in children with late primary dentition is auspicated in order to prevent an influence on dental arches growth.

Maxillary protraction to treat pediatric obstructive sleep apnea and maxillary retrusion: a preliminary report

INTRODUCTION

Midface retrusion creates a size deficiency problem in the upper airway that has been improved in children using surgical midface advancement and orthopedic protraction of the maxilla. The results of these treatments have been mostly promising at enlarging the pharyngeal airway. Recently introduced bone anchored maxillary protraction (BAMP) uses implant inserted devices in the jaws to pull the maxilla forward against a backward pressure to the lower jaw. This is a pilot study that examines the use of BAMP as a strategy to treat maxillary retrusion, malocclusion and children with obstructive sleep apnea.

METHODS

15 children, ages 9-16 years with maxillary retrusion creating a skeletal malocclusion were treated with bone anchored maxillary protraction (BAMP) and the results were compared against an untreated control group. 8 children in the treatment group also had sleep disordered breathing/obstructive sleep apnea. All subjects had lateral cephalograms before and after BAMP therapy. The OSA cohort completed the pediatric sleep questionnaire (PSQ) and polysomnography prior to and at the end of BAMP.

RESULTS

The majority of the OSA children (n = 5) showed improvement in their apnea-hypopnea index (AHI) and OSA symptoms after BAMP. Preliminary results of BAMP therapy show improvement in respiratory and airway parameters in OSA children with a highly significant change in the forward position of the upper jaw and enlargement in the nasopharyngeal to oropharyngeal junction as compared to an age and sex matched untreated control group. The outcomes were dependent on the age of treatment initiation and patient compliance.

CONCLUSIONS

This preliminary work suggests that bone anchored maxillary protraction may be considered as an adjunctive treatment option in adolescents for improving midface retrusion and sleep apnea, but further work is needed to explore this therapy.

Comparison of hyoid bone positions and pharyngeal airway dimensions in different body mass index percentile adolescent subjects

OBJECTIVE

Increased body mass index (BMI) is a growing problem worldwide and can affect medical conditions through morphological structures. The purpose of this study was to examine the hyoid bone position and pharyngeal airway dimensions on the sagittal section in different BMI percentile adolescent subjects.

METHODS

Fifty-five adolescent patients were subdivided into three groups, considering their BMI percentiles: Normal-weight (16 subjects), overweight (20 subjects), and obese (19 subjects). A total of 13 linear and angular parameters of head posture angle, pharyngeal airway dimensions, and hyoid bone positions were investigated on 55 lateral cephalometric radiographs.

RESULTS

Except for one hyoid bone measurement (RGN-H), there was no significant difference among groups. The RGN-H distances of obese and overweight adolescent subjects were higher than normal-weight adolescent subjects.

CONCLUSION

Obese, overweight, and normal-weight adolescent subjects were likely to have similar hyoid bone position and pharyngeal airway dimensions.

Three-dimensional study of the upper airway in different skeletal Class II malocclusion patterns

OBJECTIVES

To characterize upper airway volume and morphology in patients with different skeletal patterns of Class II malocclusion compared to Class I.

MATERIALS AND METHODS

A total of 197 individuals who had cone-beam computed tomography were allocated into groups according to ANB, SNA, and SNB angles (Class I, Class II maxillary protrusion, Class II mandibular retrusion), each subdivided into hypodivergent, normal, and hyperdivergent. Nasopharynx (NP), oropharynx (OP), and hypopharynx (HP) were assessed with three-dimensional image reconstruction software.

RESULTS

Intergroup comparison did not detect significant differences in volume and morphology of NP, OP, and HP. The males displayed larger OP and HP volume than the females. Positive correlations between age and NP, OP, HP volume and between craniocervical angle and OP and HP volume were observed. Linear regression analysis detected a tendency for OP and HP volume to increase as maxillary and mandibular length increased.

CONCLUSIONS

Upper airway volume and morphology were similar in different skeletal patterns of Class II malocclusion. Actual upper and lower jaw lengths were more closely related to upper airway volume and morphology than the angles that reflected their position relative to the cranial base.

Cone Beam Computed Tomography in Orthodontics

Orthodontists treat malocclusions by applying three-dimensional forces. For years, the diagnosis of this three-dimensional condition and the related treatment plan has been based on two-dimensional imaging. Lateral and anteroposterior cephalometric, panoramic, and periapical radiographs are some of the two-dimensional radiographs routinely used in orthodontics. Despite being highly beneficial in evaluating skeletal and dental relations, these radiographs fail to provide sufficient two-dimensional information in certain cases. The purpose of this compilation is to review the use of cone-beam computed tomography in orthodontics.

Application of Personalized, Predictive, Preventative, and Participatory (P4) Medicine to Obstructive Sleep Apnea. A Roadmap for Improving Care?

Dr. Leroy Hood promotes a paradigm to advance medical care that he calls P4 medicine. The four Ps are: personalized, predictive, preventative, and participatory. P4 medicine encourages a convergence of systems medicine, the digital revolution, and consumer-driven healthcare. Might P4 medicine be applicable to obstructive sleep apnea (OSA)? OSA should be personalized in that there are different structural and physiological pathways to disease. Obesity is a major risk factor. The link between obesity and OSA is likely to be fat deposits in the tongue compromising the upper airway. Clinical features at presentation also vary between patients. There are three distinct subgroups: (1) patients with a primary complaint of insomnia, (2) relatively asymptomatic patients with a high prevalence of cardiovascular comorbidities, and (3) excessively sleepy patients. Currently, there have been limited efforts to identify subgroups of patients on the basis of measures obtained by polysomnography. Yet, these diagnostic studies likely contain considerable predictive information. Likewise, there has currently been limited application of -omic approaches. Determining the relative role of obesity and OSA for particular consequences is challenging, because they both affect the same molecular pathways. There is evidence that the effects of OSA are modified by the level of obesity. These insights may lead to improvements in predicting outcomes to personalized therapies. The final P-participatory-is ideally suited to OSA, with technology to obtain extensive data remotely from continuous positive airway pressure machines. Providing adherence data directly to patients increases their use of continuous positive airway pressure. Thus, the concept of P4 medicine is very applicable to obstructive sleep apnea and can be the basis for future research efforts.

"Silent" Sleep Apnea in Dentofacial Deformities and Prevalence of Daytime Sleepiness After Orthognathic and Intranasal Surgery

PURPOSE

The purposes of this study were to determine the occurrence of undiagnosed "silent" obstructive sleep apnea (OSA) in dentofacial deformity (DFD) patients at initial surgical presentation and to report on the level of daytime sleepiness in DFD patients with OSA and chronic obstructive nasal breathing (CONB) after undergoing bimaxillary, chin, and intranasal surgery.

MATERIALS AND METHODS

A retrospective cohort study of patients with a bimaxillary DFD and CONB was implemented. Patients were divided into those with no OSA (group I) and those with OSA (group II). Group II was further subdivided into patients referred with polysomnogram (PSG)-confirmed OSA (group IIa) and those with a diagnosis of OSA only after surgical consultation, airway evaluation, and a positive PSG (group IIb). Group II patients were analyzed at a minimum of 1 year after surgery (range, 1 to 10 years) for daytime sleepiness with the Epworth Sleepiness Scale. Patients with postoperative excessive daytime sleepiness were assessed for risk factors and continued need for OSA treatment. Patients in group II were studied to determine which DFD patterns were most associated with OSA. We compared the prevalence of OSA between our study population and the general population.

RESULTS

Two hundred sixty-two patients met the inclusion criteria. Of these, 23% (60 of 262) had PSG-confirmed OSA (group II). This rate was much higher than that found in the general population. Of the patients, 7% (19 of 262) were known to have OSA at initial surgical consultation (group IIa). An additional 16% (41 of 262) were later confirmed by PSG to have OSA (group IIb). Patients with primary mandibular deficiency and short face DFDs were most likely to have OSA (P < .001 and P = .001, respectively). In group II, 91% (55 of 60) rated their daytime sleepiness as "not sleepy" at a minimum of 1 year after surgery. A significant association was found between group II patients with postoperative excessive daytime sleepiness ("sleepy" or "very sleepy") and a preoperative body mass index category of overweight (P = .026).

CONCLUSIONS

Our study found silent OSA to be frequent in the DFD population. The prevalence of OSA in DFD patients exceeded that estimated in the general population, with retrusive jaw patterns most affected. In DFD patients also presenting with OSA and CONB, we confirmed low levels of daytime sleepiness long-term after simultaneous bimaxillary orthognathic, chin, and intranasal surgery.

Obstructive sleep apnea: in search of precision

Introduction

Obstructive sleep apnea (OSA) is a highly prevalent condition that is viewed as a major global health concern, while affecting approximately 10% of the middle-aged population. OSA is a chronic disease that has been conclusively associated with poor quality of life, cognitive impairments and mood alterations, enhanced cardiovascular and metabolic morbidity, thereby leading to marked increments in healthcare costs.

Areas covered

The authors have reviewed the current evidence on the pathophysiology of OSA and its consequences, the heterogeneity of its phenotypic expression, the current therapeutic applications and their efficacy, and the implications for diagnosis, treatment and follow-up strategies in the context of the clinical management of OSA.

Expert commentary

Personalized medicine in OSA identifies different needs and approaches: i) phenotyping and defining the different and segregated clusters of OSA patients whose recognition may improve prognostic predictions and guide therapeutic strategies; ii) to further characterize and predict the impact of OSA and its treatment, particularly revolving around mortality and the processes closely related to ageing (cardiovascular diseases, cancer and neurocognitive diseases); iii) the introduction of new technologies including telemedicine that have shown promise in the implementation of personalized medicine approaches.

Occlusal traits and orthodontic treatment need in 7- to 10-year-olds in Estonia

The aim of this study was to evaluate the distribution of occlusal traits and orthodontic treatment need and complexity in Estonian 7- to 10-year-old children. This data provides solid information for planning of orthodontic care. Data of 392 Estonian children (198 girls and 194 boys, mean age 9.0 years, range 7.1-10.4 years) was analysed in this cross-sectional study. Assessed traits included first molar and canine sagittal relationship, overjet, overbite, crowding, midline diastema, crossbite, and scissor bite. Orthodontic treatment need and complexity were assessed using the Index of Complexity, Outcome, and Need. Parents' opinion regarding their child's teeth was determined using a questionnaire. The most prevalent occlusal traits were canine class I sagittal relationship (73.7%), midline diastema (73.0%), molar class I sagittal relationship (57.4%), and overbite ≥3.5 mm (51.8%). According to the Index of Complexity, Outcome, and Need, 64.3% of Estonian elementary school children were in need of orthodontic treatment. Treatment complexity was simple in 12.5%, mild in 38.8%, moderate in 22.7%, difficult in 14.0%, and very difficult in 12.0% of the children. Approximately 66.4% of the parents felt that their child needed orthodontic treatment. This study confirms earlier findings indicating that the most frequent sagittal relationship is class I in the first molars and class I in the canines. However, the sagittal relationship was asymmetric in more than half of the children. Correlation between objectively defined treatment need and parents' desire for treatment was high in Estonia.

Orthodontic view in the diagnoses of obstructive sleep apnea

Obstructive sleep apnea is an exciting area for orthodontists to be involved. The level of awareness of sleep apnea and related health issues is growing rapidly. The demand of integrating sleep into the orthodontic practice shortly will be driven by the need of the societies as some of our patients will be shortly coming into our offices aware of sleep apnea. However, with our busy clinical orthodontic practice, the need of condense short review become more demanding. Therefore, this review will try to summarize the clinical and orthodontic observation in the diagnoses of adult obstructive sleep apnea with clinical application in orthodontic practice.

Changes in posterior airway space and hyoid bone position after surgical mandibular advancement

OBJECTIVE

To evaluate cephalometric changes in posterior airway space (PAS) and in hyoid bone distance to mandibular plane (MP) 1-3 years after bilateral sagittal split osteotomy (BSSO).

MATERIAL AND METHODS

The sample consisted of 36 females and 16 males who underwent mandibular advancement by BSSO. To observe sagittal changes in PAS and in hyoid bone distance to MP both pre- and postoperative cephalograms were analyzed using WinCeph^® 8.0 software. For the statistical analyses paired T-test and multivariate logistic regression models were used.

RESULTS

By the surgical-orthognathic treatment the sagittal dimension of PAS showed variable changes but it mainly diminished when the mandibular advancement exceeded 6 mm. In most cases the hyoid bone moved superiorly by BSSO. Logistic regression models showed that males, patients with narrow PAS at the baseline, and those with counterclockwise rotation of the mandible by the treatment gained more increase in PAS. However, an increase in sagittal PAS dimension tended to relapse over time. Concerning the movement of the hyoid it was found that the more PAS increased the less hyoid moved superiorly. In males the change in hyoid position was more obvious than in females.

CONCLUSION

Males, patients with narrow PAS at the baseline, and those whose mandible moved in the counterclockwise direction with moderate advancement gained more retrolingual airway patency by BSSO.

Facial phenotype in obstructive sleep apnea-hypopnea syndrome: a systematic review and meta-analysis

This systematic review and meta-analysis explores the association between facial phenotype and obstructive sleep apnea-hypopnea syndrome in adults. A comprehensive electronic (Medline via Ovid, Scopus, and Embase) database and reference search were undertaken in relation to imaging modalities for surface craniofacial assessments in subjects with sleep apnea. The outcome measures were surface facial dimensions, morphology and profile. The quality of studies was assessed and a meta-analysis conducted. The studies were weighted using the inverse variance method, and the random effects model was used to analyse data. This systematic review identified eight case-control studies. In five studies (906 participants), adults with sleep apnea showed increased weighted mean differences in neck circumference by 1.26 mm (P = 0.0001) with extensive heterogeneity between studies (I² = 93%). Only two studies (467 participants) shared the following outcomes: mandible length, lower facial height, mandible width and anterior mandible height parameters. The pooled results demonstrated obstructive sleep apnea syndrome was associated with larger parameters than controls. In conclusion, the surface facial assessment was able to demonstrate some characteristic morphological features, facilitating a meta-analysis, in adults with obstructive sleep apnea-hypopnea syndrome. The strength of these findings, however, was limited by the heterogeneity of the studies precluding the identification of a clear phenotype.

Cephalometric Measurements With Multislice Computed Tomography in Patients With Obstructive Sleep Apnea Syndrome

INTRODUCTION

Obstructive sleep apnea syndrome (OSAS) is characterized by episodes of upper respiratory tract obstruction, decreased oxygen saturation, and sleep fragmentation during sleep, as well as excessive daytime somnolence. Cephalometric analysis offers distance, angle, area, and volume measurements between separate reference points belonging to bony and soft tissues on a film. Cephalometric measurements made with multislice computed tomography (CT) are quite helpful for standardization of measurements and obtaining highly reliable results. The aim of the current study was to make cephalometric measurements with multislice CT in OSAS patients and compare their results with those of a healthy control population. The authors also aimed to determine, which cephalometric parameters might be more valuable for diagnosis of OSAS.

MATERIALS AND METHOD

This study included 30 patients who were diagnosed with severe OSAS (apnea-hypopnea index >30) by an overnight polysomnography study, performed for suspected OSAS and 10 healthy controls without snoring or apnea who underwent three-dimensional head & neck multislice CT for any indication. All patients underwent a three-dimensional head & neck multislice CT to make cephalometric measurements and compare them across the groups.

RESULTS

ANS-PNS (anterior and posterior nasal spine), Go-Gn, and UP-PhW distances, as well as sella-nasion-A and sella-nasion-B angles, were significantly lower in the OSAS group compared with the controls (P < 0.05). Mandibulas plane -H, UD, TT-EA, ANS-B, PNS-TB, TT-TB, B-N, and PNS-PhW distances were significantly higher in the patient group compared with the controls (P < 0.05).

CONCLUSIONS

Our study reached the conclusion that some cephalometric measurements showed significant differences in patients with obstructive sleep apnea compared with the control group, and hence may lead to a susceptibility to having OSAS. Cephalometric measurements performed with multislice CT have come to the forefront as one of the most important tools for diagnosis of OSAS. An inferiorly located hyoid bone may be most commonly responsible for apnea episodes. It was also concluded that an inferiorly located hyoid bone might have been the result of maxillomandibular underdevelopment.

Craniofacial and upper airway morphology in adult obstructive sleep apnea patients: A systematic review and meta-analysis of cephalometric studies

Obstructive sleep apnea (OSA) is one of the common sleep breathing disorders in adults, characterised by frequent episodes of upper airway collapse during sleep. Craniofacial disharmony is an important risk factor for OSA. Overnight polysomnography (PSG) study is considered to be the most reliable confirmatory investigation for OSA diagnosis, whereas the precise localization of site of obstruction to the airflow cannot be detected. Identifying the cause of OSA in a particular ethnic population/individual subject helps to understand the etiological factors and effective management of OSA. The objective of the meta-analysis is to elucidate altered craniofacial anatomy on lateral cephalograms in adult subjects with established OSA. Significant weighted mean difference with insignificant heterogeneity was found for the following parameters: anterior lower facial height (ALFH: 2.48 mm), position of hyoid bone (Go-H: 5.45 mm, S-H: 6.89 mm, GoGn-H: 11.84°, GoGn-H: 7.22 mm, N-S-H: 2.14°), and pharyngeal airway space (PNS-Phw: -1.55 mm, pharyngeal space: -495.74 mm² and oro-pharyngeal area: -151.15 mm²). Significant weighted mean difference with significant heterogeneity was found for the following parameters: cranial base (SN: -2.25 mm, S-N-Ba: -1.45°), position and length of mandible (SNB: -1.49° and Go-Me: -5.66 mm) respectively, maxillary length (ANS-PNS: -1.76 mm), tongue area (T: 366.51 mm²), soft palate area (UV: 125.02 mm²), and upper airway length (UAL: 5.39 mm). This meta-analysis supports the relationship between craniofacial disharmony and obstructive sleep apnea. There is a strong evidence for reduced pharyngeal airway space, inferiorly placed hyoid bone and increased anterior facial heights in adult OSA patients compared to control subjects. The cephalometric analysis provides insight into anatomical basis of the etiology of OSA that can influence making a choice of appropriate therapy.