Evaluation of craniofacial morphology in patients with obstructive sleep apnea using lateral cephalometry and dynamic MRI

Radiographic findings predictive of obstructive sleep apnea in adults: A systematic review and meta-analysis

Polysomnography remains the diagnostic gold standard for obstructive sleep apnea (OSA), but it cannot be easily performed in a timely fashion within the practice of a craniomaxillofacial surgeon. Hence, in this systematic review and meta-analysis, we aimed to identify radiographic indicators that could predict obstructive sleep apnea (OSA) diagnosis. We conducted a PRISMA-compliant systematic review and meta-analysis, including 109 studies with 9817 participants (3509 controls, 6308 OSA patients), predominantly male (79% controls, 85% OSA patients). The analysis focused on CT (36, 33%), MRI (23, 21%), and lateral cephalogram findings (50, 46%). The average age and BMI for the included patients were 44.4 ± 14.4 years and 26.4 ± 5.2 kg/m2 for controls, and 51.5 ± 40.4 years and 29.8 ± 6.4 kg/m2 for the OSA group. A random-effects model meta-analysis was conducted on the measurements that met our criteria. Due to measurement differences between studies, only lateral cephalogram measurements could be included in the meta-analysis: OSA correlated with increased soft palate length and thickness, increased mandibular plane to hyoid bone distance, and decreased SNA, SNB, BaSN, SN distance, and palatal length (ANS-PNS). Although the study underscores radiographic utility for screening, PSG is necessary to establish a diagnosis of OSA.

Assessment of cephalometric parameters and correlation with the severity of the obstructive sleep apnea syndrome

BACKGROUND

In individuals diagnosed with obstructive sleep apnea syndrome (OSAS), variations in craniofacial structure have been inconsistently documented, showing differing degrees of alteration between obese and nonobese patients. In addition, sleep disturbance has also been shown to induce disequilibrium in this population of patients. This pilot observational study aimed to assess craniofacial values in obese and nonobese subpopulations of patients with OSAS and their correlation and association with the severity of OSAS. We also assessed whether OSAS patients are characterized by an impaired equilibrium in relation to and associated with the severity of OSAS.

METHODS

We included all consecutive adult patients with OSAS. Through cephalometry, we assessed the upper (UPa-UPp) and lower (LPa-LPp) pharynx diameters, superior anterior facial height (Sor-ANS), anterior facial height (ANS-Me), anterior vertical dimension (Sor-Me), posterior facial height (S-Go) and craniovertebral angle (CVA). Furthermore, we analyzed postural equilibrium through a stabilometric examination.

RESULTS

Forty consecutive OSAS patients (45% female with a mean age of 56 ± 8.2 years) were included. The subgroup of nonobese patients had a reduced UPa-UPp (p = 0.02). Cephalometric measurements were correlated with the severity of OSAS in nonobese patients, whereas only Sor-ANS was correlated with the severity of OSAS in the obese subpopulation. In the overall population, altered craniofacial values are associated with severe OSAS. Although there are differences in equilibrium between obese and nonobese OSAS patients, the stabilometric measurements were not correlated or associated with OSAS severity.

CONCLUSION

Altered craniofacial values and compromised equilibrium in OSAS patients are linked to OSAS severity. Therefore, the management of OSAS should be tailored not only to weight management but also to craniofacial and postural rehabilitation to enhance patient outcomes.

Computed Tomography versus Sleep Endoscopy (DISE) to Predict the Effectiveness of Mandibular Advancement Devices in Adult Patients with Obstructive Sleep Apnea: A Protocol for Systematic Review

Obstructive sleep apnea is a sleep disorder with a high prevalence in the world population. The mandibular advancement device is one of the options for treating obstructive sleep apnea. Neck computed tomography and drug-induced sleep endoscopy are complementary diagnostic tests that may help predict the effectiveness of mandibular advancement devices. This study aims to analyze the best method for predicting the effectiveness of mandibular advancement devices in the therapeutic approach to obstructive sleep apnea. PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science Core Collection databases will be comprehensively searched. We will include randomized clinical trials, non-randomized prospective or retrospective clinical studies, case controls, cohort studies, and case series. Two authors will independently conduct data extraction and assess the literature quality of the studies. The analysis of the included literature will be conducted by Revman 5.3 software. The outcomes that will be analyzed are craniofacial characteristics, cephalometric assessments, site and type of obstruction of the upper airway, mean values of the apnea-hypopnea index, and SaO2 verified in the initial and follow-up polysomnography. This study will provide reliable, evidence-based support for the clinical application of mandibular advancement devices for obstructive sleep apnea.

The Link between Obstructive Sleep Apnea Syndrome and Cephalometric Assessment of Upper Airways and Hyoid Bone Position

Background and Objectives: To determine whether there are changes in the cephalometric characteristics of the upper airways and hyoid bone, in patients diagnosed with obstructive sleep apnea syndrome (OSAS) compared to a healthy control group. Material and Methods: This retrospective case−control study included 24 patients diagnosed with OSAS (apnea−hypopnea index (AHI) > 5 obtained after polysomnography) and 24 healthy subjects as a control group that completed the STOP-Bang questionnaire to determine whether they had OSAS. Lateral cephalometric examinations were recommended for all these patients. The software used for the cephalogram interpretation was CS 3D Imaging and CS Airway imaging from Carestream Dental. Results: The subjects with OSAS had a smaller superior posterior airway space (SPAS), with an average of 10.32 mm compared to a 12.20 mm mean in the control group (p = 0.03). Patients with OSAS, had a lowered middle airway space (MAS) with a mean of 7.96 mm in the OSAS group and a 10.96 mm mean in the control group (p = 0.00). All the measurements made for the hyoid bone, such as—H-MnP, H-C3, and H-B—showed increased values (means of 26.31 mm, 39.08 mm, 60.05 mm, respectively), for the OSAS group (p = 0.00). Conclusions: Patients suffering from OSAS had reduced dimensions of the SPAS and MAS values. The hyoid bone had a more inferior position in the study group (with increased values for H-MnP, H-C3, and H-B) compared to the control group.

Impact of Hyoid Position, Mandible Body Length and Anthropometric Measurements on Sleep Indices in Patients with Snoring in North Indian Population

Introduction

In Indian population, the estimated prevalence of OSA is 7.5% to 13.5%. Craniofacial anatomical variations and obesity are the major risk factors for OSA. Among the craniofacial anatomy, the neck circumference and abnormal craniofacial morphology play an important role in the pathogenesis of OSA. Obesity is the major risk factor for which waist and hip circumference and BMI are considered.

Aim

The aim of this paper was to evaluate the impact of hyoid position, mandible body length (MBL) and anthropometric measurements on sleep indices in patients with snoring in North Indian population.

Methods

In this cross-sectional study, we analyzed the position of the hyoid, mandible body length and anthropometric measurements, of 104 patients attending ENT OPD with the complaint of snoring and excessive daytime sleepiness. All subjects underwent a full overnight polysomnography. The position of the hyoid, MBL and the anthropometric measurements were compared with the sleep architecture of the subjects, and a p value < 0.05 was considered significant.

Results

A strong positive correlation is seen between the position of the hyoid, MBL and anthropometric measurements on the sleep indices in this study. Pearson 2-tailed correlation was evaluated, and upon analysis, it was found that at significance level of 0.01, obesity (BMI) is strongly correlated with overall AHI with correlation coefficient of 0.926, whereas AHI in supine position was having coefficient of 0.837 and AHI on right side and left side was almost same 0.597 and 0.575, respectively. Similarly WC is strongly correlated with AHI and RDI, having coefficient of 0.930 with both. NC and HC also showed strong positive correlation with overall AHI and RDI having correlation coefficient of 0.893, 0.926 with AHI and 0.893, 0.926 with RDI, respectively. The MBL also showed a strong positive correlation with AHI and RDI with correlation coefficient of 0.994 in both. The position of the hyoid also showed a strong positive correlation with AHI and RDI.

Conclusion

Results indicated that significant positive correlation was found between position of the hyoid, MBL and anthropometric measurements on the sleep indices in patients with snoring in North Indian population.

Evaluation of Central Obesity, Increased Body Mass Index, and its Relation to Oropharyngeal Airway Space Using Lateral Cephalogram in Risk Prediction of Obstructive Sleep Apnea

Introduction

Maxillofacial radiologists play a significant role in detecting airway changes using radiographic tools. Clinical examination parameters and lateral cephalogram parameters play a vital role in diagnosing obstructive sleep apnea (OSA) and dreadful consequences.

Aim and Objectives

This study aims to evaluate central obesity, increased body mass index (BMI), and its relation to oropharyngeal airway space using lateral cephalogram in risk prediction of OSA. Objectives are to measure central obesity and BMI.

Methodology

BMI is measured using World Health Organization guidelines to measure oropharyngeal airway space and the tongue and soft palate area using lateral cephalogram to predict OSA's risk using Berlin's questionnaire. Age group between 18 and 60 years with 20 individuals in each group will be present in the study.

Conclusion

Cephalometric upper airway space and soft-tissue variables in different BMI groups were compared, and it was found that there was a decrease in SPAS, MAS with an increase in BMI, and in patients with BMI <24, there was narrower nasopharynx and oropharynx.

Impact of counterclockwise rotation of the occlusal plane on the mandibular advancement, pharynx morphology, and polysomnography results in maxillomandibular advancement surgery for the treatment of obstructive sleep apnea patients

PURPOSE

Evaluate the impact of counterclockwise rotation of the occlusal plane (CCWROP) on pharynx morphology and polysomnography in maxillomandibular advancement (MMA) surgery to treat obstructive sleep apnea (OSA) patients.

METHODS

Prospective clinical trial of patients with OSA treated by MMA. Computed tomography and polysomnography were performed pre- and postoperatively and the parameters were compared. The surgery classified the patients into two groups: with (R) and without (NR) CCWROP.

RESULTS

The study sample comprised 38 individuals: R (n = 19) and NR (n = 19). An anterior mandible advancement of 0.71 mm was identified for each degree of CCWROP (p < 0.001). As for polysomnography, the apnea-hypopnea index was reduced by 80% and 62% in R and NR, showing final values of 6.8 and 13.0, respectively. The apnea index changed equally in both groups. Reduction of 68 and 26% in the hypopnea index was observed for R and NR, respectively, with no statistically significant difference. Total volume increased by 45% in R and 30% in NR. Retropalatal and retrolingual volumes increased by 49% and 4% in R and 43% and 15% in NR, respectively. The minimum axial area increased by 92% in the retropalatal region and 97% in the retrolingual region in R, whereas these increases were of 76% and 31% in NR, respectively.

CONCLUSION

Anterior mandibular advancement of 0.71 mm for each degree of CCWROP is of great importance for surgical planning. As a result of this resource, individuals in R presented better results than those in NR in all parameters assessed, especially regarding the retrolingual region.

Effect of mandibular advancement device treatment on HIF-1α, EPO and VEGF in the myocardium of obstructive sleep apnea-hypopnea syndrome rabbits

The aim of this study was to investigate the effects of mandibular advancement device (MAD) therapy for obstructive sleep apnea-hypopnea syndrome (OSAHS) on hypoxia-inducible factor-1α (HIF-1α), erythropoietin (EPO) and vascular endothelial growth factor (VEGF) in myocardial tissue. New Zealand rabbits were used to develop OSAHS and MAD models. Cone beam computed tomography (CBCT) of the upper airway and polysomnography (PSG) recordings were performed with the animals in the supine position. All of the animals were induced to sleep in a supine position for 4-6 h each day and were observed continuously for 8 weeks. The myocardial tissue of the three groups was dissected to measure the expression of HIF-1α, EPO and VEGF. The results showed that there was higher expression of HIF-1α, EPO and VEGF in the OSAHS group than those in the MAD and control groups. MAD treatment significantly downregulated the expression of HIF-1α, EPO and VEGF in the OSAHS animals. We concluded that MAD treatment could significantly downregulate the increased expression of HIF-1α, EPO and VEGF in OSAHS rabbits, improving their myocardial function.

Craniofacial morphology in patients with obstructive sleep apnea: cephalometric evaluation

Introduction

Obstructive sleep apnea is characterized by a reduced airflow through the upper airways during sleep. Two forms of obstructive sleep apnea are described: the central form and the obstructive form. The obstructive form is related to many factors, such as the craniofacial morphology.

Objective

To evaluate the correlation between the morphology of the cranial base, of the mandible and the maxilla, and obstructive sleep apnea severity.

Methods

Eighty-four patients, mean age of 50.4 years old; 73 males and 11 females with obstructive sleep apnea were enrolled in the present study. Patients with high body mass index and comorbidities were excluded. Lateral cephalograms and polysomnography were collected for each patient to evaluate the correlation between craniofacial morphology and obstructive sleep apnea severity. A Spearman’s rho correlation test between cephalometric measurements and obstructive sleep apnea indexes was computed. Statistical significance was set at p < 0.05.

Results

Patients with a severe obstructive sleep apnea presented a reduction of sagittal growth of both effective mandibular length and cranio-basal length. The mandibular length was the only variable with a statistical correlation with apnea-hypopnea index. Vertical dimension showed a weak correlation with the severity of obstructive sleep apnea. No correlation with maxillary sagittal dimension was shown.

Conclusion

Obstructive sleep apnea severity may be correlated to mandibular and cranial base growth. Facial vertical dimension had no correlation with obstructive sleep apnea severity.

A spirometric and cephalometric comparative evaluation of mandibular advancement devices and occlusal jig

Aim

Aim of the current study was to evaluate the effect of occlusal jig with increased vertical dimension and mandibular advancement device on the oropharangeal volume in completely edentulous patients using spirometry and cephalometry.

Materials and Methods

The current study included includes 30 completely edentulous patient according to inclusion criteria. They were each subjected to cephalometric and spirometric analysis wearing CCD, OJ & MAD. Results obtained were subjected to following statistical analysis, one-way ANOVA test, unpaired t-test, and Dunnett's test.

Result

Both OJ & MAD brings about significant change in oropharangeal volume hence both the devices are effective treatment of choice for OSA, while greater increase was observed in oropharangealvolume of OJ as compared to MAD. Spirometric analysis shows insignificant changes in the oropharangeal volume caused by MAD while OJ causes small but significant change in oropharangeal volume (PIFR].

Conclusion

Within the limitation of the study, it can be concluded that, on cephalometric & spirometric evaluation, OJ shows greater increase in oropharangeal volume when compared to MAD in completely edentulous patient.

Airway increase after open bite closure with temporary anchorage devices for intrusion of the upper posteriors: Evidence from 2D cephalometric measurements and 3D magnetic resonance imaging

OBJECTIVE

The aim of this study was to analyse morphological changes in the upper airways in patients with anterior open bite treated with temporary anchorage devices for intrusion of upper posterior teeth.

MATERIALS AND METHODS

Twelve nonobese (body mass index: <25) anterior open bite patients between the ages of 19 and 44 years (mean age: 22.83 ± 8.19 years) were recruited for this study. Cephalometric radiographs and magnetic resonance imaging (MRI) scans before and after anterior bite closure without bracketing on anterior teeth were used to measure the upper airway, which was divided into retropalatal and retroglossal regions.

RESULTS

The mandibular plane angle and lower facial height were significantly reduced by intrusion of the upper posteriors and autorotation of the mandible. The retroglossal airway width (AW2) and retroglossal area (RG area) measured on cephalometric radiographs both increased significantly after treatment. Retroglossal volume increased and the retroglossal width/length ratio decreased significantly in MRI analysis. All other measurements were not significantly changed. However, no statistically significant correlations were observed between all measurements in 2D and 3D images, with the exception of the AW2 linear measurement in 2D images correlating with the AP length in MRI axial view images (r = 0.56, P = 0.0430).

CONCLUSION

Counterclockwise rotation of the mandible after anterior open bite closed using orthodontic treatment changed the airway morphology. Retroglossal volume significantly increased and the airway shape became less elliptical after bite closure.

Obstructive Sleep Apnea in a rural population in South India: Feasibility of health care workers to administer level III sleep study

Objectives:

To estimate the occurrence of obstructive sleep apnea (OSA) and its risk factors in a rural Indian population using screening questionnaire and Level III sleep study. To determine the feasibility to train community health workers to administer Level III sleep study in the high-risk population.

Materials and Methods:

The study was conducted from seven villages with adult population of 2247, in Mugalur, near Bengaluru, from January to April 2014. Berlin questionnaire was used to screen 321 participants chosen by stratified random sampling. A total of 26 out of 321 patients underwent Level III sleep study at home, administered by the health workers, who were trained in three sessions to hook up the machine. Data were verified by a certified sleep physician.

Results:

The mean age was 39.43 ± 15.6 years with the M:F ratio of 0.98:1. Prevalence of risk of OSA by Berlin questionnaire was 8.72% (95% confidence interval [CI] 5.63, 11.81) in the total population, 7.4% in males and 11.7% in females. Older age (odds ratio [OR] 3.97; CI 1.63, 9.6), hypertension (OR 11; CI 4.3, 28.2), obesity (OR 2.35; CI 1, 5.5), and higher Mallampati score (OR 3.78; CI 1.7, 8.4) were significantly associated with high risk of OSA (P = 0.0001–0.04). Twenty-six patients underwent Level III sleep study and OSA was diagnosed in 12 patients. The mean apnea–hypopnea index (AHI) of this group was 9.7/h. The prevalence of OSA by AHI criteria was 3.74%.

Conclusions:

OSA is underdiagnosed in rural populations, although risk factors are present. Training community health workers to administer Level III sleep study is a feasible and cost-effective strategy.

No correlation between two-dimensional measurements and three-dimensional configuration of the pharyngeal upper airway space in cone-beam computed tomography

The aim of this study was to evaluate both the 2-dimensional (2D) and 3-dimensional (3D) configuration of the posterior airway space (PAS) in healthy 239 patients using cone-beam computed tomography (CBCT). In particular, we investigated the correlation between the 2D and 3D measurements in view of the potential impact on diagnosis of upper airway obstruction. The pharyngeal airway of each patient was studied at five levels: the level of the posterior nasal spine (PNS), the level of half-height of the PNS and the tip of the soft palate, the level of the tip of the soft palate, the level of the anterior-inferior point of the second vertebra, and at least the level of the top of the epiglottis. At each of these levels, the anterior-posterior dimension as well as the corresponding cross-sectional area was measured. Furthermore we measured the volume of the whole PAS between the first and the last level and compared it with the corresponding 2D values. Differences between genders and age effects were estimated in an analysis of covariance. P values <.05 were considered significant. Linear models were fitted to find the optimal formula to calculate the area or volume from measured distances. Limits of agreement were calculated as 2 ± residual standard deviations. We generated normal 2D and 3D values of the PAS for a normal population. In regard to age, no significant differences were observed. Significant differences were assessed between healthy males and females; however no correlation was observed between the obtained measurements in 2D axial view and the corresponding cross-sectional areas and mean volume in 3D view. In summary, radiologic imaging is a helpful tool to evaluate the airway space in patients with OSAS. However, drawing conclusions from 2D PAS imaging to assess 3D PAS configuration is not reliable, since there is no sufficient correlation between posterior-anterior distances and the corresponding cross-sectional areas.

Managing obstructive sleep apnoea in children: the role of craniofacial morphology

Obstructive sleep apnoea syndrome is a type of sleep-disordered breathing that affects 1 to 5% of all children. Pharyngeal and palatine tonsil hypertrophy is the main predisposing factor. Various abnormalities are predisposing factors for obstructive sleep apnoea, such as decreased mandibular and maxillary lengths, skeletal retrusion, increased lower facial height and, consequently, increased total anterior facial height, a larger cranio-cervical angle, small posterior airway space and an inferiorly positioned hyoid bone. The diagnosis is based on the clinical history, a physical examination and tests confirming the presence and severity of upper airway obstruction. The gold standard test for diagnosis is overnight polysomnography. Attention must be paid to identify the craniofacial characteristics. When necessary, children should be referred to orthodontists and/or sleep medicine specialists for adequate treatment in addition to undergoing an adenotonsillectomy.

Craniocervical Posture in Patients with Obstructive Sleep Apnea

INTRODUCTION

Obstructive Sleep Apnea (OSA) is characterized by repeated episodes of upper airway obstruction during sleep.

OBJECTIVE

The objective of this study is to verify the craniofacial characteristics and craniocervical posture of OSA and healthy subjects, determining possible relationships with the apnea/hypopnea index (AHI).

METHODS

This case-control study evaluated 21 subjects with OSA, who comprised the OSA group (OSAG), and 21 healthy subjects, who constituted the control group (CG). Cephalometry analyzed head posture measurements, craniofacial measurements, and air space. Head posture was also assessed by means of photogrammetry.

RESULTS

The groups were homogeneous regarding gender (12 men and 9 women in each group), age (OSAG = 41.86 ± 11.26 years; GC = 41.19 ± 11.20 years), and body mass index (OSAG = 25.65 ± 2.46 kg/m2; CG = 24.72 ± 3.01 kg/m2). We found significant differences between the groups, with lower average pharyngeal space and greater distance between the hyoid bone and the mandibular plane in OSAG, when compared with CG. A positive correlation was found between higher head hyperextension and head anteriorization, with greater severity of OSA as assessed by AHI.

CONCLUSION

OSAG subjects showed changes in craniofacial morphology, with lower average pharyngeal space and greater distance from the hyoid bone to the mandibular plane, as compared with healthy subjects. Moreover, in OSA subjects, the greater the severity of OSA, the greater the head hyperextension and anteriorization.

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.

Importance of cephalographs in diagnosis of patients with sleep apnea

Introduction:

Obstructive sleep apnea (OSA) is considered to be a potentially life threatening disorder, which is characterized by repeated collapse of the upper airway during sleep with cessation of breathing. The cephalometric method despite being a static, two-dimensional evaluation of dynamic three-dimensional structures of the head and neck is useful in diagnosing patients with OSA, as they have shown that significant differences exist between asymptomatic controls and patients with OSA.

Aims and Objectives:

This study is designed to compare and validate the craniofacial morphology in patients with OSA using lateral cephalometry in both upright and supine position.

Materials and Methods:

Sixty subjects participated in the study of which 30 were patients with OSA diagnosed by questionnaire and 30 were healthy control group with age range of 25–45 years.

Results:

The study group demonstrated an increased ANB, mandibular plane angles (GoGn-SN), lower anterior facial height which are statistically significant with a significant P < 0.05. Significant decrease in posterior airway space, increased soft palate length, tongue length, and thickness suggesting reduced airway space in supine posture.

Conclusion:

Evaluation of craniofacial morphology in OSA patients using lateral cephalometry helps in recognizing the morphological changes induced by altered sleep pattern and for appropriate treatment planning.

Diagnostic Role of Magnetic Resonance Imaging in Obstructive Sleep Apnea Syndrome

We aim to review the diagnostic role of magnetic resonance (MR) imaging in obstructive sleep apnea syndrome (OSAS). Basic background about sleep apnea, MR anatomy of the pharyngeal airway, and MR imaging sequences applied in obstructive sleep apnea are discussed. Static and dynamic MR imaging is used in the assessment of patients with OSAS. Magnetic resonance imaging can detect the level, degree, and cause of obstruction in the upper airway that guide the clinical diagnosis and treatment. Imaging is used for prediction of treatment outcome and monitoring and follow-up of patients with OSAS after therapy.

Lateral teleradiography of the head as a diagnostic tool used to predict obstructive sleep apnea

OBJECTIVES

To (1) assess the relationship between obstructive sleep apnea (OSA) and craniofacial, pharyngeal anatomy and (2) to submit the recommendations for clinicians for increasing the sensitivity in the diagnostics of OSA.

METHODS

A review of the relevant literature linking OSA in adults with cephalometric analysis was performed. In total, 11 articles with similar procedural criteria were selected. The data were analysed using the Comprehensive Meta-Analysis Software (Biostat Inc., Englewood, NJ) and Statistica 12.0 (StatSoft Inc., Dell Software, Tulsa, OK).

RESULTS

Adults with OSA did not show statistically significant differences in the sagittal and vertical skeletal planes in comparison with the controls (p > 0.05). The patients with OSA had soft palate length, width and area increased accordingly by 4.21, 1.99 mm and 0.86 cm(2), tongue area increased by 2.02 cm(2), the upper posterior pharyngeal space (SPAS) and lower posterior pharyngeal space reduced accordingly by 4.53 and 1.32 mm, mandibular plane to the hyoid bone (MP-H) distance increased by 4.14 mm compared with the controls (p < 0.05). The SPAS parameter of the patients with OSA did not show statistically significant differences between the studies, with the mean value being 5.69 mm.

CONCLUSIONS

Analysed cephalometric data totally supported the concept of soft-tissue abnormalities in subjects with OSA, skeletal-only halfway; MP-H and SPAS being the most reliable parameters. Increased MP-H may serve as a predictor when differentiating normal subjects and patients with OSA. Reduced SPAS width could be a prognostic parameter for suspecting OSA. These two values should be kept in mind by dentists and can also be used as a simple auxiliary method by physicians; nevertheless, it is still underestimated and more studies are needed.

The status of cephalometry in the prediction of non-CPAP treatment outcome in obstructive sleep apnea patients

Obstructive sleep apnea syndrome (OSAS) is the most common sleep disordered breathing disorder (SDB) in adults and is characterized by a recurrent partial or complete collapse of the upper airway during sleep. This can be caused by many factors, sometimes interacting, such as skeletal malformations, soft tissue crowding, respiratory instability and the various effects of aging, obesity and gender that dictate craniofacial and upper airway anatomy. Research has demonstrated that the majority of patients exhibit at least one anatomical component such as retrognathia or a narrow posterior airway space that predisposes to the development of OSAS. Within the predisposing elements for OSAS many seem to point to anatomical characteristics. A standardized and relatively simple radiologic technique to evaluate anatomical craniofacial relationships is cephalometry. This has been used already for a long time in orthodontics, but is now gradually being introduced in OSAS treatment to envisage optimal treatment selection as well as to predict treatment outcomes. The purpose of the present review is to evaluate the contribution of cephalometry in the prediction of outcomes from OSAS treatments that depend on the upper airway morphology in their mechanisms of action such as oral appliances that advance the mandible as well as various surgical methods. In addition, an overview of imaging modalities and methods that currently are being used in cephalometric analysis in OSAS patients is provided. The findings indicate that isolated cephalometric parameters cannot be used to reliably predict treatment outcomes from mandibular advancement devices and surgical methods for OSAS. Extreme or outlying values of cephalometric parameters may rather be used as contra-indicators or 'red flags' instead of predictors.

Correlation of cephalometric and anthropometric measures with obstructive sleep apnea severity

Introduction: Patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) often have associated changes in craniofacial morphology and distribution of body fat, either alone or in combination.

Aim: To correlate cephalometric and anthropometric measures with OSAHS severity by using the apnea-hypopnea index (AHI).

Method: A retrospective cephalometry study of 93 patients with OSAHS was conducted from July 2010 to July 2012. The following measurements were evaluated: body mass index (BMI), neck circumference (NC), waist circumference (WC), hip circumference (HC), the angles formed by the cranial base and the maxilla (SNA) and the mandible (SNB), the difference between SNA and SNB (ANB), the distance from the mandibular plane to the hyoid bone (MP-H), the space between the base of the tongue and the posterior pharyngeal wall (PAS), and the distance between the posterior nasal spine and the tip of the uvula (PNS-P). Means, standard deviations, and Pearson's correlation coefficients were calculated and analyzed.

Results: AHI correlated significantly with BMI (r = 0.207, p = 0.047), NC (r = 0.365, p = 0.000), WC (r = 0.337, p = 0.001), PNS-P (r = 0.282, p = 0.006), and MP-H (r = 0.235, p = 0.023).

Conclusion: Anthropometric measurements (BMI, NC, and WC) and cephalometric measurements (MP-H and PNS-P) can be used as predictors of OSAHS severity.

Cephalometric and anthropometric data of obstructive apnea in different age groups

INTRODUCTION

Patients with obstructive sleep apnea syndrome usually present with changes in upper airway morphology and/or body fat distribution, which may occur throughout life and increase the severity of obstructive sleep apnea syndrome with age.

OBJECTIVE

To correlate cephalometric and anthropometric measures with obstructive sleep apnea syndrome severity in different age groups.

METHODS

A retrospective study of cephalometric and anthropometric measures of 102 patients with obstructive sleep apnea syndrome was analyzed. Patients were divided into three age groups (≥20 and <40 years, ≥40 and <60 years, and ≥60 years). Pearson's correlation was performed for these measures with the apnea-hypopnea index in the full sample, and subsequently by age group.

RESULTS

The cephalometric measures MP-H (distance between the mandibular plane and the hyoid bone) and PNS-P (distance between the posterior nasal spine and the tip of the soft palate) and the neck and waist circumferences showed a statistically significant correlation with apnea-hypopnea index in both the full sample and in the ≥40 and <60 years age group. These variables did not show any significant correlation with the other two age groups (<40 and ≥60 years).

CONCLUSION

Cephalometric measurements MP-H and PNS-P and cervical and waist circumferences correlated with obstructive sleep apnea syndrome severity in patients in the ≥40 and <60 age group.

Airway changes in obstructive sleep apnoea patients associated with a supine versus an upright position examined using cone beam computed tomography

OBJECTIVE

This study aimed to describe total volume and cross-sectional area measurement changes in obstructive sleep apnoea patients associated with a supine versus an upright position.

METHOD

A retrospective chart review of patients who underwent cone beam computed tomography in upright and supine positions was performed, and the images were analysed.

RESULTS

Five obstructive sleep apnoea patients (all male) underwent both upright and supine cone beam computed tomography imaging. Mean age was 35.0 ± 9.3 years, mean body mass index was 28.1 ± 2.7 kg/m2 and mean apnoea-hypopnoea index was 39.3 ± 23.0 per hour. The airway was smaller when patients were in a supine compared with an upright position, as reflected by decreases in the following airway measurements: total volume; posterior nasal spine, uvula tip, retrolingual and tongue base (not significant) cross-sectional areas; and site of the minimum cross-sectional area (of the overall airway). Total airway volume decreased by 32.6 per cent and cross-sectional area measurements decreased between 32.3 and 75.9 per cent when patients were in a supine position.

CONCLUSION

In this case series, the airway of obstructive sleep apnoea patients was significantly smaller when patients were in a supine compared with an upright position.

"Black Bone" MRI: a potential non-ionizing method for three-dimensional cephalometric analysis--a preliminary feasibility study

OBJECTIVES

CT offers a three-dimensional solution to the inaccuracies associated with lateral cephalogram-based cephalometric analysis. However, it is associated with significant concerns regarding ionizing radiation exposure. MRI offers a non-ionizing alternative, but this has been less well investigated. We present a novel gradient echo MRI sequence ("Black Bone") and highlight the potential of this sequence in cephalometric analysis.

METHODS

After regional ethics approval, "Black Bone" imaging was obtained in eight patients in whom lateral cephalograms were available. "Black Bone", T1 and T2 weighted spin echo imaging were obtained in the mid-sagittal plane, and measurements were compared with those obtained on the lateral cephalogram using both the Advantage Windows Workstation (GE Medical Systems, Buckinghamshire, UK) and the Dolphin(®) cephalometric software (v. 11.5.04.23, Premium; Dolphin Imaging, Chatsworth, CA) by one assessor. Further assessment was made by scoring the ease of landmark identification on a ten-point scale.

RESULTS

"Black Bone" imaging surpassed T1 and T2 weighted imaging in terms of cephalometric landmark identification. A number of mid-sagittal cephalometric landmarks could not be clearly identified on T2 weighted imaging, making analysis impossible. Measurements on "Black Bone" demonstrated the smallest discrepancy when compared with those obtained on the lateral cephalogram. The discrepancy seen between measurements completed on mid-sagittal MRI and the lateral cephalogram was compounded by inherent inaccuracies of the lateral cephalogram. The overall mean discrepancy between distance measurements on "Black Bone" imaging and those on the lateral cephalogram was 1-2 mm.

CONCLUSIONS

Overall, "Black Bone" MRI offered an improved method of cephalometric landmark identification over routine MRI sequences, and provides a potential non-ionizing alternative to CT for three-dimensional cephalometrics.

Platelet-rich plasma (PRP) in dental and oral surgery: from the wound healing to bone regeneration

Platelet-rich plasma (PRP) is a new approach to tissue regeneration and it is becoming a valuable adjunct to promote healing in many procedures in dental and oral surgery, especially in aging patients. PRP derives from the centrifugation of the patient's own blood and it contains growth factors that influence wound healing, thereby playing an important role in tissue repairing mechanisms. The use of PRP in surgical practice could have beneficial outcomes, reducing bleeding and enhancing soft tissue healing and bone regeneration. Studies conducted on humans have yielded promising results regarding the application of PRP to many dental and oral surgical procedures (i.e. tooth extractions, periodontal surgery, implant surgery). The use of PRP has also been proposed in the management of bisphosphonate-related osteonecrosis of the jaw (BRONJ) with the aim of enhancing wound healing and bone maturation. The aims of this narrative review are: i) to describe the different uses of PRP in dental surgery (tooth extractions and periodontal surgery) and oral surgery (soft tissues and bone tissue surgery, implant surgery and BRONJ surgery); and ii) to discuss its efficacy, efficiency and risk/benefit ratio. This review suggests that the use of PRP in the alveolar socket after tooth extractions is certainly capable of improving soft tissue healing and positively influencing bone regeneration but the latter effect seems to decrease a few days after the extraction. PRP has produced better results in periodontal therapy in association with other materials than when it is used alone. Promising results have also been obtained in implant surgery, when PRP was used in isolation as a coating material. The combination of necrotic bone curettage and PRP application seem to be encouraging for the treatment of refractory BRONJ, as it has proven successful outcomes with minimal invasivity. Since PRP is free from potential risks for patients, not difficult to obtain and use, it can be employed as a valid adjunct in many procedures in oral and dental surgery. However, further RCTs are required to support this evidence.