Cephalometric and polysomnographic analyses of functional magnetic system therapy in patients with obstructive sleep apnea

Comparative assessment of changes in pharyngeal airway space in cases of obstructive sleep apnoea with a customized mandibular repositioning appliance - a clinical study

Objectives

The present study aims at evaluating the effects of a customized mandibular repositioning appliance on the pharyngeal airway, nocturnal sleep patterns, daytime discomfort and occlusal changes in established cases of adult obstructive sleep apnoea.

Material and Methods

Ten consecutive patients with a complaint of snoring and disturbed sleep were included in the study. The primary diagnosis was established by the Epworth sleepiness scale, clinical examination, history and subsequently the diagnosis was substantiated through assessment of the pharyngeal airway space on a lateral cephalogram and polysomnography. A customized mandibular repositioning appliance was used to advance the mandible sequentially every 6 months, using 4 sets of the appliance. Pre and post-treatment evaluations were performed to establish, effects and changes in the outcome of obstructive sleep apnoea.

Results

The study revealed significant increase in the mean pharyngeal widths of upper airway and velum dimension with antero-superior repositioning of hyoid bone. Epworth sleepiness scale score improved significantly from baseline with clinically evident change in daytime discomforts. Significant decline in the mean apnoea/hypopnea index, oxygen desaturation index, respiratory disturbance index, heart rate, snoring and a significant increase in mean oxygen saturation of arterial blood was observed. No evident change noticed in occlusion except lower incisor inclination.

Conclusion

The customized mandibular repositioning appliances are effective in the management of adult obstructive sleep apnoea with a significant improvement observed in the airway patency and polysomnography parameters with clinically non-significant effects on dental occlusion..

The clinical characteristics of patients with an isolate epiglottic collapse

OBJECTIVE

We analyzed the clinical characteristics of patients with isolated epiglottic collapse (IEC) who had an epiglottic anteroposterior (AP) collapse as the only cause of snoring during drug-induced sleep endoscopy (DISE).

METHODS

A retrospective analysis of 334 consecutive DISE examinations was performed. Patients who had only epiglottic AP collapse were designated as the IEC group. There were four age- and sex-matched controls for each case, and these patients were designated as the control group. Demographic factors, polysomnography findings, cephalometry, and awake nasopharyngoscopic findings were analyzed.

RESULTS

A total of 11 IEC cases and 44 controls were included. The IEC group had a significantly lower apnea-hypopnea index, higher minimum oxygen saturation level, lower body mass index, and shorter mandible plane to hyoid distance than the controls. However, there were no differences in epiglottic shape or curvature between the two groups. In addition, no IEC was noted during awake endoscopy. Nine (81.8%) epiglottic collapses were resolved with the mouth open and jaw thrust maneuver, which simulated the use of an oral appliance. Six (54.4%) were resolved with head turning, mimicking the lateral sleep position.

CONCLUSION

The clinical characteristics of IEC patients differed from the control group, and IEC could not be identified during awake endoscopy. Therefore, patients with severe snoring but AHI < 5 or mild sleep apnea on polysomnographic findings and DISE, should be considered likely to have IEC. In addition, use of an oral appliance is recommended as an effective treatment for IEC.

Maximum voluntary retrusion or habitual bite position for mandibular advancement assessment in the treatment of obstructive sleep apnoea patients

BACKGROUND

There is no consensus on whether the range of mandibular advancement for the construction of mandibular advancement devices in obstructive sleep apnoea (OSA) patients should be measured from a starting position of maximum voluntary retrusion or habitual bite position.

OBJECTIVE

The purposes of this study were to investigate the differences in mandibular advancement registrations starting from maximum voluntary retrusion or from habitual bite position and to evaluate the reliability of these assessments.

METHODS

A retrospective cohort analysis of 126 patients with OSA was performed. All patients had their mandibular range of motion evaluated twice (starting from maximum voluntary retrusion and from habitual bite position) through the George Gauge before undergoing drug-induced sleep endoscopy. The Dahlberg formula and paired t test were used to calculate random and systematic errors of dental positions assessment. Test-retest reliability was quantified using the intra-class correlation coefficient (ICC).

RESULTS

The mean mandibular range starting from maximum voluntary retrusion and from habitual bite position were 12.49 ± 2.19 mm and 7.68 ± 2.29 mm, respectively, with a mean distance between the two starting positions of 4.81 ± 1.75 mm. No systematic error was found (P > .05), and random errors ranged from 0.30 to 0.95 mm. ICC values were excellent for maximum voluntary protrusion (ICC = 0.986) and maximum voluntary retrusion (ICC = 0.956), whereas habitual bite position showed a good value (ICC = 0.818).

CONCLUSION

The difference between maximum voluntary retrusion and habitual bite position is potentially relevant. Maximum retrusion is advisable as starting point of the mandibular advancement registration since it provides a more reliable measure.

Post-treatment evaluation of a magnetic activator device in Class II high-angle malocclusions

SUMMARY

The purpose of this study was to evaluate changes in dentofacial growth before, during, and after use of a magnetic activator device (MAD) II in high-angle Class II division 1 patients. Lateral cephalometric and hand-wrist radiographs of 10 patients (six girls and four boys) with an average chronological age of 10 years 5 months were obtained at the beginning of the observation period (T1, 9.5 months), beginning of MAD II application (T2), at the end of the treatment (T3), and approximately 4 years after the end of treatment (T4). Thirteen linear, 1 ratio, and 10 angular measurements were evaluated. Paired t-tests were used for statistical evaluation of differences that occurred between the time points. The increase in gonial angle, GnGoAr angle, S-N, Co-Gn, Go-Ar, ANS-Me, S-Go, and N-Me distances and the decrease of overjet, U1-NA distance, and ANB angle were statistically significant during the treatment. At T4, there was a decrease in gonial angle and U1-NA distance, which was significant. The changes as a result of treatment were stable at T4.

Surgical cephalometrics: applications and developments

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the historical origins of modern cephalometry. 2. Identify common landmark points on the lateral cephalogram. 3. Describe multiple common clinical uses for cephalometry. 4. Exhibit knowledge of developments in imaging and analysis alternatives.

BACKGROUND

Interest in the dimensions of the human head has been present since antiquity. Proportional analysis and measures from cadaveric specimens led to the development of radiologic image capture and analysis on living subjects. These techniques were originally applied to establishing normative values, documenting growth, and diagnosing dentofacial disharmonies. This article reviews the origins of cephalometric methodology and current developments and applications.

METHODS

The authors conducted a MEDLINE search and review of all English language articles using the keywords "cephalometric" and "cephalometrics."

RESULTS

Cephalometrics have undergone substantial use and development since the introduction of radiologic imaging on living human subjects in 1931. Although frequently associated with orthognathic surgery, cephalometrics have been applied to a number of conditions involving altered craniofacial morphology. Advances in imaging and computing have led to increased interest in three-dimensional and non-x-ray-based assessment of the human head. Mathematical models have been applied to standard cephalometric information to increase the descriptive accuracy of the complex shapes involved.

CONCLUSIONS

Cephalometric techniques and analyses are versatile tools that can be applied to a wide variety of clinical scenarios involving the craniofacial region. New technologies and expanded applications promise to continue the development and use of this well-established methodology.

Treatment of snoring and obstructive sleep apnea with mandibular repositioning appliances

Snoring and obstructive sleep apnea form part of a spectrum of sleep disordered breathing affecting a significant proportion of the general population and particularly the middle aged. The consequences can be severe and even life threatening for both the individual directly affected and those more remotely involved. Adverse sequelae can manifest themselves acutely or in the longer term as a result of obstructive breathing induced hypersomnolence, neurocognitive deficits and cardiovascular abnormalities. The combination of anatomical and neuromuscular risk factors in the pathogenesis of OSA has resulted in a varied approach to its management. One such treatment option is mandibular repositioning appliances (MRA), which mechanically stabilize the airway. Whilst the efficacy of this simple intervention has been rigorously proven quite recently in a significant proportion of patients with varying disease severity, individual patient selection in its application remains uncertain. Short-term side-effects are common but usually transient, whilst in the long-term minor permanent adverse developments on the dentition and occlusion have been reported. Considering both the medicolegal implications of snoring and OSA and the increasing popularity of MRA, it is recommended that skilled multidisciplinary respiratory and dental personnel form the primary care team.

Oral Appliance Therapy for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common disorder characterized by repetitive, complete or partial closure of the upper airway during sleep, resulting in sleep fragmentation and oxygen desaturation. The disorder causes significant morbidity, particularly in terms of impairment of daytime functioning and the impact this has on quality of life. There is also evidence that links OSA to long-term cardiovascular morbidity, including hypertension, myocardial infarction, and stroke, and increased risk of motor vehicle accidents. There is clear evidence that effective treatment of OSA provides major benefit to patients. Nasal continuous positive airway pressure (CPAP) is the current treatment of choice, but its cumbersome nature makes tolerance and compliance less than optimal. This gives rise to the need for other alternatives that are equally effective, but more tolerable. There is growing interest in the use of oral appliances to treat snoring and OSA. The rationale is that advancement of the mandible and tongue impacts positively on upper airway caliber and function. There are many such types of appliances, and they have potential advantages over CPAP in that they are unobtrusive, make no noise, do not need a power source, and are potentially less costly. There is a growing evidence base to support the use of oral appliances in the management of OSA. Recent evidence from randomized controlled trials indicates that oral appliance therapy is effective in controlling OSA in up to 50% of patients, including some patients with more severe forms of OSA. This is associated with a significant improvement in symptoms, including snoring and daytime sleepiness. This evidence is strong for short term, and emerging for long-term treatment of OSA with oral appliances. Whilst direct comparisons with CPAP indicate the superiority of CPAP overall, similar outcomes between the two treatments appear to be achieved in a substantial subgroup of patients. Patient acceptance has, in general, been in favor of oral appliances. Notwithstanding the expanding role of oral appliance therapy, there are a number of limitations that are yet to be overcome. Key issues include the inability to reliably predict treatment outcome, the apparent need for an acclimatization period to attain maximal efficacy of treatment, uncertainty about selection of the appropriate 'dosage' of mandibular advancement required to control OSA in the individual patient, uncertainty about the influence of appliance design on treatment outcome and adverse effects, adherence to treatment, and potential long-term complications of therapy. These issues require resolution before oral appliance therapy can surpass CPAP as first-line treatment for OSA.