Sleep-Disordered Breathing: Choosing the Right Cephalometric Analysis

Cephalometric analyses for cleft patients: a statistical approach to compare the variables of Delaire's craniofacial analysis to Bergen analysis

Objectives

Cephalometric analyses using lateral craniofacial radiographs are common diagnostic procedures for evaluating skeletal patterns. However, in patients with pronounced abnormalities like cleft lip and palate, standard cephalometric analyses and landmarks may not be suitable. This study aims to clarify whether the inclusion of landmarks less compromised by the cleft defect or located outside the cleft area results in a different cephalometric assessment of the viscerocranium. Delaire’s whole-skull analysis and Bergen analysis were examined for similarities and underlying common observations.

Materials/methods

Based on the cephalometric evaluation of 217 patients with different types of non-syndromal cleft formation, Delaire and Bergen analysis were compared using three statistical methods: correlation analysis, factor analysis, and cluster analysis. Reproducibility was assessed by Bland–Altman plots, intraclass correlation coefficients, mean absolute differences, and coefficients of variability.

Results

Although Delaire analysis and Bergen analysis are based on different concepts and landmarks, a majority of corresponding variables was found. Certain aspects of craniofacial base relation and craniospinal articulation are only assessed by Delaire analysis. All but one variable showed very good reproducibility.

Conclusions

The inclusion of landmarks less compromised by or located outside the cleft area does not result in variables that provide a different assessment of the viscerocranial area.

Clinical Relevance

The findings contradict the concept of invalidity of landmarks compromised by the cleft defect or located within the affected cleft area. Within the scope of its viscerocranial field of view, Bergen analysis appears to be on a par with Delaire analysis in the diagnosis of cleft patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04006-3.

Maxillary stability following Le Fort I osteotomy using prebent plates and wire fixation in patients undergoing surgery for OSAS

The purpose of this study was to analyze the stability of Le Fort I maxillary advancement in the vertical and horizontal directions using a combination of wire and rigid fixation in patients undergoing surgery to treat obstructive sleep apnea (OSA). Wire osteosynthesis can be performed quicker and at a reduced cost. The lateral cephalograms of 21 patients were evaluated preoperatively (T0), immediately postoperatively (T1), and at least 6 months postoperatively (T2). Four cephalometric points were used to measure movement in the horizontal and vertical directions. Mean values were determined, and data were statistically analyzed by ANOVA to determine differences between time points. Of the four points analyzed, the average maxillary advancement in the horizontal direction was 7.48 mm and the relapse was 0.56 mm with absence of statistically significant differences between the measurements taken (T1) and (T2). There was a 5% probability of error in the vertical movements at the points I and posterior nasal spine. The combination of two pre-bent plates in piriform aperture with osteosynthesis using surgical steel wires in the zygomatic buttress in patients undergoing maxillary surgery for OSA stabilized the large horizontal maxillary advancements and enhanced vertical stability in the first molar and A point regions.

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.

Preoperative cephalometric analysis to predict transoral robotic surgery exposure

Transoral robotic surgery (TORS) is being increasingly used in the treatment of head and neck cancer and we wanted to determine the feasibility of predicting TORS access using cephalometric measurements obtained from preoperative imaging. 20 cephalometric measurements were obtained from imaging on 31 TORS base of tongue (BOT) resections and compared to adequacy of exposure. Three measurements were found to be significantly different between the restricted and adequate exposure groups. Distances from posterior pharyngeal wall (PPW) to hyoid, PPW to soft palate and epiglottis to vertical laryngeal angle were all statistically different between the two groups. Receiver operating characteristic (ROC) analysis revealed strong correlation to exposure for all three measurements with cut offs ≤30 mm between the PPW and the hyoid, ≤8.1 mm PPW and soft palate and ≥130° between the epiglottis and vertical plain of the larynx all representing restricted exposure. Duration of surgery for the restricted group, 85 min, was significantly longer than the adequate exposure group, 51 min (p = 0.026). Preoperative measurements of radiographic images of the oropharyngeal working space can predict restricted exposure for TORS resection of the BOT. These measures may be used in conjunction with other subjective assessment parameters to predict which patients could benefit from a staging endoscopy to determine adequate TORS exposure.

Correlation between cephalometric data and severity of sleep apnea

INTRODUCTION

Obstructive sleep apnea syndrome has a high prevalence among adults. Cephalometric variables can be a valuable method for evaluating patients with this syndrome.

OBJECTIVE

To correlate cephalometric data with the apnea-hypopnea sleep index.

METHODS

We performed a retrospective and cross-sectional study that analyzed the cephalometric data of patients followed in the Sleep Disorders Outpatient Clinic of the Discipline of Otorhinolaryngology of a university hospital, from June 2007 to May 2012.

RESULTS

Ninety-six patients were included, 45 men, and 51 women, with a mean age of 50.3 years. A total of 11 patients had snoring, 20 had mild apnea, 26 had moderate apnea, and 39 had severe apnea. The distance from the hyoid bone to the mandibular plane was the only variable that showed a statistically significant correlation with the apnea-hypopnea index.

CONCLUSION

Cephalometric variables are useful tools for the understanding of obstructive sleep apnea syndrome. The distance from the hyoid bone to the mandibular plane showed a statistically significant correlation with the apnea-hypopnea index.

Lateral cephalometric analysis and the risks of moderate to severe obstructive sleep-disordered breathing in Thai patients

PURPOSES

This cross-sectional study was aimed to compare lateral cephalometric parameters among patients with different severities of obstructive sleep-disordered breathing and to determine if there are radiographic variables that increase risk of moderate to severe obstructive sleep apnea (OSA).

METHODS

Ten linear and 5 angular parameters of lateral cephalometry in 188 adult subjects which included 47 controls and 141 patients with OSA classified by apnea-hypopnea index (AHI) from level-I polysomnography, were analyzed. All radiographs were done under standardized processes and measured twice on separate occasions.

RESULTS

There were statistically significant differences between controls and patients with AHI ≥ 15 in parameters such as a distance from mandibular plane to hyoid (MP-H), posterior airway space (PAS), skull base angle (NSBA), a distance from posterior nasal spine to posterior pharyngeal wall (PNS-PP), and soft palate length (PNS-P), (p < 0.01). However, no significant difference was found between controls and mild OSA. Logistic regression analysis showed that only MP-H with cutoff point of ≥ 18 millimeters, NSBA ≤ 130°, and PAS ≤ 10 millimeters were independent cephalometric variables that increased risk of having AHI ≥ 15 compared to controls with adjusted odds ratio of 17.1, 8.3 and 4.2, respectively. Gender did not significantly associate with OSA severity in this analysis.

CONCLUSIONS

Patients who had longer MP-H, narrower PAS and narrower NSBA than specific cutoff points significantly increased risks of moderate to severe OSA. Treatments that effectively improve these parameters, particularly at tongue base level (MP-H and PAS), may decrease the severity of disease.

Changes in facial profile after maxillomandibular advancement surgery for obstructive sleep apnea syndrome

The aim of this study was to assess changes in the profile of adult male patients treated for obstructive sleep apnea syndrome (OSAS) with maxillomandibular advancement (MMA) surgery and to measure patient perception of changes compared with that of different panels.

MATERIALS AND METHODS

Fifteen consecutive apneic patients displaying a wide variety of morphological types, mean age 42 years (20-59), a BMI of 26.60 kg/m(2) (22-29), a mean initial Apnea Hypopnea Index (AHI) of 50.9 (19-85), underwent MMA. Assessment was done by facial photography, lateral cephalographs (Tweed analysis modified by Riley and Delaire architectural analysis), polysomnographic records and a validated self-assessment questionnaire. Patients' pre- and postoperative profiles were taken from photographs using Photoshop 7™ software. Their darkened outlines were shown randomly in positions A or B (pre- and postoperative) to panels composed of orthodontists (n=40), fine arts students (n=50) and lay persons (n=50) who were requested to choose the most attractive profiles.

RESULTS

The MMA success rate for OSAS was 80% (12/15) for an AHI less than 15, with no surgical complications. All patients reported a reduction of their symptoms and 14 out of 15 were satisfied with the esthetic outcome. Mean advancement was 8.4mm (3.0-10.0) for the maxilla and 10.8mm (10.0-13.0) for the mandible. Following MMA, 12 out of 15 exhibited maxillary protrusion and six out of 15 mandibular protrusion. The mean change in the nasolabial angle was -5.7° (-27°; 14°). The postoperative profiles were preferred by 85% of the combined panels (P=<0.001), showing no significant difference from one panel to another. No skeletal characteristic could be correlated with the esthetic preference. Upper lip retrusion, open nasolabial angle and dolichofacial type emerged as positive preoperative predictors of esthetic preference.

CONCLUSION

The profile changes following MMA were favorably perceived in the majority of cases. However, specific orthodontic preparation could be offered to patients with pronounced preoperative protrusion.