Mandibular advancement device therapy for obstructive sleep apnea: a prospective study on predictors of treatment success.

OBJECTIVE: To survey potential predictors of success of mandibular advancement device (MAD) therapy in patients with obstructive sleep apnea (OSA), and in particular, to examine anatomical narrowings and sleep-related collapse levels in the upper airway. METHODS: This was a prospective study of 62 OSA patients (median apnea-hypopnea index [AHI] of 34), who were treated with a custom-made, monobloc MAD. The upper airway was examined by inspection, nasopharyngoscopy, overnight acoustic reflectometry recording collapses, and cephalometry of soft tissue dimensions (in addition to skeletal parameters). MAD treatment was controlled by polysomnograpy before and after at least five weeks from the beginning of treatment. Independent predictors of actual reduction in AHI and treatment success (reduction in AHI ≥ 50% with residual AHI < 10) were determined, using multivariable linear and logistic regression. RESULTS: Positional OSA (POSA) and nonsupine AHI (adjusted for upper airway narrowness and collapses, together with gender, age, body mass index, neck circumference, and baseline AHI) were the only independent predictors: POSA indicative for success, and nonsupine AHI inversely related to success. Cephalometry was not predictive. Two predictive models were proposed, one based on POSA having a specificity of 70% and sensitivity of 69%, and the other based on nonsupine AHI, generating a receiver operating characteristic (ROC) curve (area under ROC = 0.78). Using the ROC model, specificity could be increased to 80% without lowering sensitivity. CONCLUSIONS: Only variables related to sleep position proved to be independent predictors of success with MAD therapy. The results could be explained by the MAD counteracting the mandible from moving backwards when sleeping supine.

Pharyngeal Airway Dimensions and Head Posture in Obstructive Sleep Apnea Patients with and without Morphological Deviations in the Upper Cervical Spine.

OBJECTIVES: The aim of the study was to analyse differences in pharyngeal airway dimensions and head posture between obstructive sleep apnea patients with and without morphological deviations in the upper cervical spine and to analyse associations between pharyngeal airway dimensions and head posture in the total sample. MATERIAL AND METHODS: The sample comprised 53 obstructive sleep apnea (OSA) patients of which 32.1% had upper spine morphological deviations. Accordingly two groups were defined: 17 OSA patients with morphological deviations in the upper spine and 36 without upper spine deviations. Pharyngeal airway dimensions in terms of distances, cross-sectional areas and volume and upper spine morphological deviations were evaluated on cone-beam computed tomography. Head posture was evaluated on two-dimensional generated lateral cephalograms. Differences were analysed and adjusted for age and gender by multiple linear regression analysis. RESULTS: OSA patients with upper spine morphological deviations had a significantly more backward and curved neck posture (OPT/HOR, P < 0.01; OPT/CVT, P < 0.05) compared to OSA patients without spine deviations. No significant differences were found in airway dimensions between patients with and without upper spine deviations. In the total group significant associations were found between head posture and pharyngeal airway distances and cross-sectional area at the nasal floor, epiglottis and hyoid bone level (P < 0.05, P < 0.01, P < 0.001). No significant association was found between head posture and airway volume. CONCLUSIONS: The results may contribute to differentiate obstructive sleep apnea patients and thereby may prove valuable in diagnosis and treatment planning of obstructive sleep apnea patients.

Osseous osteoarthritic-like changes and joint mobility of the temporomandibular joints and upper cervical spine: is there a relation?

OBJECTIVES: To compare 1) temporomandibular joint (TMJ) mobility between patients with and without reduced upper cervical spine (UCS) mobility and with and without TMJ osseous osteoarthritic-like changes, and 2) UCS osseous changes between patients with and without TMJ osseous osteoarthritic-like changes and with and without reduced UCS mobility. STUDY DESIGN: The study comprised 39 patients without pain from TMJ or UCS and with obstructive sleep apnea, 15 women (age range 26-72 years, mean 56.0) and 24 men (age range 27-71 years, mean 49.8). The range of motion (ROM) of the mandible and UCS was assessed clinically. Osseous changes of the TMJ and UCS were assessed by cone beam computed tomography. Differences were tested and adjusted for age and gender by multiple linear and logistic regression analyses. RESULTS: The mandibular ROM was within normal range (45-64 mm) but the UCS ROM was reduced in 15 patients. Osseous TMJ and UCS changes were both found in 38.5% of the patients. Osseous UCS changes were found more frequently in patients with than without TMJ changes (P = .0003; odds ratio 21.9). No other significant results were found. CONCLUSIONS: The present findings of comorbid osseous changes in patients with obstructive sleep apnea support a possible biomechanical relationship between the TMJ and the UCS.

Influence of craniofacial and upper spine morphology on mandibular advancement device treatment outcome in patients with obstructive sleep apnoea: a pilot study.

BACKGROUND/OBJECTIVES: The aim of the study was to assess cephalometric predictive markers in terms of craniofacial morphology including posterior cranial fossa and upper spine morphology for mandibular advancement device (MAD) treatment outcome in patients with obstructive sleep apnoea (OSA). MATERIAL/METHODS: Twenty-seven OSA patients were treated with MAD for 4 weeks. Apnoea-hypopnoea index (AHI) was recorded before and after MAD treatment. The criteria of treatment success were 75 per cent reduction of AHI. Accordingly, two groups occurred: the success treatment group of 8 patients and the no success treatment group of 19 patients. Before MAD treatment lateral cephalograms were taken and analyses of the craniofacial morphology including the posterior cranial fossa and upper spine morphology were performed. Differences between the groups were analysed by Fisher's exact test, t-test, and multiple regression analysis. RESULTS: Upper spine morphological deviations occurred non-significantly in 25 per cent in the success treatment group and in 42.1 per cent in the no success treatment group. Body mass index (BMI; P < 0.05), maxillary prognathism (S-N-Ss; P < 0.01), mandibular prognathism (S-N-Pg; P < 0.05 and S-N-Sm; P < 0.01), and the distance between sella turcica and the deepest point in posterior cranial fossa (S-D; P < 0.05) was significantly smaller in the success treatment group. The maxillary prognathism (P < 0.05) was the most important factor for the MAD treatment outcome (R (2) = 0.47). LIMITATIONS: Relatively small sample size. CONCLUSIONS: The results indicate that BMI, posterior cranial fossa morphology, and retrognathia of the jaws are factors related to MAD treatment outcome. Furthermore, OSA patients with upper spine morphological deviations may respond poorer to MAD treatment.

Bony deviations revealed by cone beam computed tomography of the temporomandibular joint in subjects without ongoing pain.

AIMS: To assess the prevalence of temporomandibular joint (TMJ) bony changes in cone beam computed tomography (CBCT) images of adult subjects without ongoing orofacial pain or complaints from the TMJ. METHODS: The study included 84 TMJs from 28 men and 14 women (mean age [± SD]: 51 ± 11 years) without orofacial pain or TMJ complaints who were participants in a study of patients with obstructive sleep apnea. They were examined before any treatment with the Research Diagnostic Criteria for Temporomandibular Disorders and with CBCT (NewTom VGi; 15 × 15 cm, exposure time 18 seconds, axial thickness 0.3 mm). Osseous TMJ deviations were assessed blindly and classified. RESULTS: Degenerative changes were noted in the CBCT images of 33 (39.3%) of the TMJs, of which 21 were classified as osteoarthritic alterations and 12 as indeterminate changes of osteoarthritis. Two TMJs were clinically classified as osteoarthrosis and 6 as disc displacement with reduction. The CBCT images of the 2 TMJs with a clinical diagnosis of osteoarthrosis showed also bony changes, but the CBCT images also revealed osteoarthritic bony changes in the 18 TMJs without any clinical diagnosis. CONCLUSION: CBCT images of asymptomatic adult TMJs commonly show degenerative bony alterations. Accordingly, such radiographic findings should be used with care and only as a supplement to clinical assessment.

Associations between craniofacial morphology, head posture, and cervical vertebral body fusions in men with sleep apnea.

INTRODUCTION: The aim of this study was to analyze craniofacial profiles and head posture in patients with obstructive sleep apnea (OSA) subgrouped according to cervical column morphology. METHODS: Seventy-four white men aged 27 to 65 years (mean, 49.0 years) diagnosed with OSA in sleep studies by using overnight polysomnography were included. Only patients with apnea-hypopnea index scores between 5.1 and 92.7 (mean, 36.4) were included. Lateral profile radiographs in standardized head posture were taken, and cephalometric analyses of sagittal and vertical jaw relationships were made. The patients were divided into 4 groups according to fusion in the cervical vertebrae: group I, no fusions (42 subjects); group II, fusion of cervical vertebrae 2 and 3 (15 subjects); group III, occipitalization (10 subjects); and group IV, block fusion (11 subjects). Mean differences of craniofacial dimensions between the groups were assessed by unpaired t tests. RESULTS: No significant differences were seen between groups I and III. Between groups I and II, significant differences were seen in jaw relationship (P < 0.05). Between groups I and IV, anterior face height and mandibular length deviated significantly. No significant differences were seen in head posture. CONCLUSIONS: OSA patients with block fusions in the cervical vertebrae and fusion of 2 vertebrae differed significantly in craniofacial profile from other OSA patients.

Cervical column morphology in adult patients with obstructive sleep apnoea.

Cervical column morphology was examined in adult patients with obstructive sleep apnoea (OSA) and compared with the cervical morphology of an adult control group with neutral occlusion, normal craniofacial morphology, and no history of sleep apnoea. The sleep apnoea group consisted of 91 patients, 16 females aged 29-59 years (mean 49.4 years) and 75 males aged 27-65 years (mean 49.0 years). All patients were diagnosed with OSA by overnight polysomnography. The control group consisted of 21 subjects, 15 females aged 23-40 years (mean 29.2 years) and 6 males aged 25-44 years (mean 32.8 years). From each individual, a visual assessment of the cervical column was performed on the radiograph. Differences in the cervical column morphology, between the genders and the groups were assessed by Fisher's exact test and the effect of age by logistic regression analysis. In the OSA group, 46.2 per cent had fusion anomalies of the cervical column and 5.5 per cent a posterior arch deficiency. Fusion anomalies occurred in 26.4 per cent as fusions between two cervical vertebrae. Block fusions occurred in 12.1 per cent and occipitalization in 14.3 per cent. A posterior arch deficiency occurred in 2.2 per cent as a partial cleft of C1 and in 3.3 per cent as dehiscence of C3 and C4. No statistical gender differences were found in the occurrence of morphological characteristics of the cervical column. The fusion anomalies of the cervical column occurred significantly more often in the OSA group. The results indicate that the morphological deviations of the upper cervical vertebrae play a role in the phenotypical subdivision and diagnosis of OSA.

Mandibular advancement appliance for obstructive sleep apnoea: results of a randomised placebo controlled trial using parallel group design.

The aim of this trial was to evaluate the efficacy of a mandibular advancement appliance (MAA) for obstructive sleep apnoea (OSA). Ninety-three patients with OSA and a mean apnoea-hypopnoea index (AHI) of 34.7 were centrally randomised into three, parallel groups: (a) MAA; (b) mandibular non-advancement appliance (MNA); and (c) no intervention. The appliances were custom made, in one piece. The MAAs had a mean protrusion of the mandible of 74% (range 64-85%). Outcome measures, assessed after continuous use for 4 weeks, were AHI (polysomnography), daytime sleepiness (Epworth) and quality of life (SF-36). Eighty-one patients (87%) completed the trial. The MAA group achieved mean AHI and Epworth scores significantly lower (P < 0.001 and P < 0.05) than the MNA group and the no-intervention group. No significant differences were found between the MNA group and the no-intervention group. The MAA group had a mean AHI reduction of 14.1 (95% CI 7.4-20.8), and a mean Epworth score reduction of 3.3 (95% CI 1.8-4.8). Eight MAA patients (30%) achieved a reduction in AHI > or = 75% ending with an AHI < 5, half of them having baseline AHI > 30. Sensitivity analyses confirmed these results. MAA had a significant beneficial effect on the vitality domain of SF-36. Four MAA patients (14.8%) and two MNA patients (8%) discontinued interventions because of adverse effects. Our conclusion is that MAA has significant beneficial effects on OSA, including cure in some cases of severe OSA. Protrusion of the mandible is essential for the effect. MNA has no placebo effect. MAA may be a good alternative to CPAP in subsets of OSA patients.