Obstructive Sleep Apnea- Dr.M.M.varadharaja / orthodontic courses by Indian dental academy

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INDIAN DENTAL ACADEMY

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Contents • Introduction • Anatomic aspects • Patho-Physiologic aspect• Clinical features• Morbidity of Obstructive Sleep Apnea• Diagnostic procedures• Upper Airway Imaging techniques• Management

– Nasal continuous positive airway pressure– Oral Appliances– Surgical management

• Conclusion • References www.indiandentalacademy.com

Introduction

• Over the past two decades, medicine and dentistry have focused on breathing disorders during sleep

• These are commonly considered to be snoring, upper airway resistance syndrome and obstructive sleep apnea.


Snoring

• Snoring, the commonest of sleep disorders is found in 25% of adult males

• Snoring is the result of base of tongue compromising the upper airway when the patient falls asleep

• The patient increases the speed of airflow in an attempt to maintain required oxygen, which causes vibration of soft tissues - Snoring


• Snoring by itself is not considered a serious problem, because its mainly a problem that creates irritation and loss of sleep in their bed partners

• However, because almost all patients with Obstructive Sleep Apnea snore, it must be considered a potential indicator of significant medical problems


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Definition of Obstructive Sleep Apnea

• Broadbent (1877), described Obstructive Sleep Apnea as “ there will be perfect silence through two, three, or four respiratory periods, in which there are ineffectual chest movements; finally air enters with a loud snort, after which there are several compensatory deep inspirations”


• Obstructive Sleep Apnea is potentially life threatening condition in which periodic cessation of breathing occurs during sleep in the presence of inspiratory effort

• Obstructive Sleep Apnea affects not only the quality of life but also has significant morbidity

• The reduction in blood oxygen saturation may give rise to hypertension, cardiac arrhythmias, nocturnal angina and myocardial ischemia


Anatomic aspects of Obstructive Sleep Apnea


• Upper airway can be viewed in four areas(1) Nasopharynx –

– Mainly involves the nose, begins with nares and ends at superior portion of hard palate

– Structures of major concern – Nasal Turbinates and Nasal Septum

– Inferior turbinates, the largest of the three, is commonest to enlarge causing blockade of nasal passage

– Deviated nasal septum may affect nasal respiration


Nasal Turbinates and Deviated Nasal Septum


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• (2) Velopharynx– It extends from hard palate to the inferior tip of

soft palate– It includes uvula and upper part of posterior

wall of pharynx– The muscles of major concern are the Tensor

Palatini and Levator Palatini


• (3) Oropharynx– It comprised of oral cavity, beginning with

back portion of mouth till base of the tongue– Major components – Tongue and Tonsils– Enlargement of these structures causes

airway obstruction– Within this area there are number of muscles

that control posture of tongue and mandible, and these muscles also serves to maintain airway


(4) Hypopharynx • It extends from epiglottis to the lower

portion of airway at larynx• Large number of muscles affect this

portion can have varying effect depending on concurrent activity of related muscles



Muscular relationships and functions

• Palatoglossus and Palatopharyngeus– Located in anterior and

posterior tonsillar pillar– As the mandible is advanced,

these muscles are spread apart, causing tension on palatoglossus.

– This is transferred to soft tissue, thus reducing vibration

– Hence snoring may be reduced or eliminated by mandibular advancement


• Muscles of the neck– These support the cervical spine– Alteration in the cervical spine can

modify the airway, primarily through the effect on hyoid bone, which in turn can affect mandibular position

– Therefore, its important that during the clinical examination, posture of individual and its potential impact on airway be considered


Other muscles that might influence airway

• Levator Palatini and Tensor Palatini• Muscles of the Tongue• Suprahyoids and Infrahyoids• Constrictor muscles of pharynx• Stylopharyngeus and

Salphingopharyngeus – during speech and swallowing


Patho-Physiologic aspect of Obstructive Sleep Apnea


• Although Sleep Apnea might be central, obstructive and mixed pattern in origin, the Obstructive type is the most common form

• It is characterized by cessation of airflow because of upper airway obstruction despite simultaneous respiratory effort

• The respiratory effort continues despite obstruction until the individual is aroused from sleep


Normal alterations during sleep

• Normal physiologic alterations that are associated with sleep may predispose individual to Obstructive Sleep Apnea

• During sleep – The upper airway is more collapsible than

during wakefulness, – Ventilation and inspiratory flow decreases,– Upper airway resistance increases and– Arterial carbon dioxide tension increases


Hypotonicity of muscles of upper airway

• Hypotonicity of muscles of upper airway is the primary factor predisposing normal upper airway to increased collapsibility in sleep

• Upper airway inspiratory muscles and thoracic muscles work in apposition

• Upper airway inspiratory muscles exerting a dilatory effect, while thoracic muscles produce sub atmospheric intra-airway pressure which has collapsing effect on upper airway www.indiandentalacademy.com

Constriction of upper airway• Frequently, sleep apnea patients have

constricted upper airways that increase pharyngeal resistance during inspiration

• This necessitates an increase in pharyngeal dilator muscle contraction to maintain patency

• Such increase has been shown in Obstructive Sleep Apnea patients during wakefulness, but it decreases during sleep, thus contributing to development of Obstructive Sleep Apneawww.indiandentalacademy.com

Predisposing factors • Obesity – airway is compromised because of

more fat deposits in soft palate, tongue and surrounding pharynx

• Alcohol ingestion – decrease in hypoglossal nerve output while phrenic nerve output is spared

• REM sleep – muscles of airway are most hypotonic in this stage of sleep

• Pharyngeal length was found to be longer in apnea patients in supine position compared with upright position


Anatomic alterations reducing airway – Ivanhoe - J Prosth Dent 1999

• Posteriorly positioned maxilla and mandible

• Steep occlusal plane• Overerupted anterior teeth• Large gonial angle• Anterior openbite associated with large

tongue• Posteriorly placed pharyngeal walls


• Retrognathic mandibles• Large tongue and soft palate• Large anteroposterior discrepancies

between maxilla and mandible• Micrognathia• Acromegaly • Downs’ syndrome


Hereditary variables

• Adenoid and tonsillar hypertrophy• Glottic webs• Vocal cord paralysis• Lymphoma or Hodgkin’s disease• Ectopic thyroid• Systemic disease involving mandible like

Rheumatoid arthritis• Severe Kypho-Scoliosis• Cushing syndrome


Clinical features of Obstructive Sleep Apnea


Clinical features

1.Excessive sleepiness2.Morning headaches3.Gastro-esophageal

reflux disease4. Impaired concentration5.Depression 6.Decreased libido7. Irritability

1.Snoring 2.Drooling3.Xerostomia4.Diaphoresis 5.Choking or

gasping

Nocturnal symptoms Daytime symptoms


Mishra P and Valiathan A – J Nep Med Assoc - 1995

Sleep onset

Apnea

Oxygen , pH, carbon dioxide

Arousal from sleep

Resumption of Airflow

Return to Sleep

Negative oro-pharyngeal pressure

Reduced upper airway muscle activity

Small pharyngeal cavity

High pharyngeal compliance

High upstream resistance

Baseline arterial Oxygen concentration

Degree of diffuse airway

Obstruction

Lung volume

Chemoreceptor sensitivity

CNS abnormality www.indiandentalacademy.com

Orofacial characteristics in Obstructive Sleep Apnea

• Retrognathic mandible• Narrow palate• Large neck circumference• Long soft palate• Tonsillar hypertrophy• Nasal septal deviation• Relative macroglossia


Obstructive Sleep Apnea in children

• Snoring is the characteristics of Obstructive Sleep Apnea in children

• Nonetheless many children may not have snoring as a major complaint even in presence of severe upper airway obstruction

• Other associated clinical features are– Difficulty in breathing during sleep– Restless sleep– Morning headaches– Enuresis – Sleep terrorswww.indiandentalacademy.com

• Day time abnormalities includes sleepiness, attention span problems, poor social performance

• Other symptoms which may be seen are– Upper airway infections– Sinusitis – Otitis media– Failure to thrive– In severe cases pulmonary hypertension or

cor pulmonale can develop


Epidemiology

• Estimates of prevalence of Obstructive Sleep Apnea vary widely. Largely because of different cutoff point for diagnosis

• Battagel BJO 1996 stated that figures for middle-aged adults range from 1.3 to 24%

• Almost all studies report higher incidence in males than in females, and agree that the condition is greater in obese

• The prevalence is normally described as increasing with age


Morbidity of Obstructive Sleep Apnea

• Morbidity of Obstructive Sleep Apnea relates principally to cardiovascular system

• Rigorous epidemiological studies have shown that Sleep Apnea is a risk factor for development of Arterial Hypertension, independent of associated obesity, alcohol intake, sex, and age

• Now studies have found increasing evidence to demonstrate that Obstructive Sleep Apnea is an independent risk factor for Stroke


• Lavie 2003 investigated repeated apnea related events to atherogenesis through initiation of oxidative stress, hypothesizing a molecular biological association between hypoxia-reoxygenation episodes of Obstructive Sleep Apnea and cardiovascular disease

• Among other consequences of Sleep Apnea, excessive daytime sleepiness, cognitive impairment, impaired ability to drive motor vehicle and increased automobile accident have been documented


• Many studies have agreed that patients with Obstructive Sleep Apnea have reduced quality of life

• Jennum 2002 showed clear association between headache and sleep disturbances, however the cause and effect of this relationship is not clear

• Patients with headache also report more daytime symptoms like fatigue, tiredness or sleepiness

• Identifying sleep disorders in chronic headache patients is worthwhile, as improvement of headache may follow treatment of sleep disorders in this group


Diagnostic procedures in Obstructive Sleep Apnea


• The diagnosis of Obstructive Sleep Apnea is best done by a pulmonologist or other physician specialized in sleep breathing problems.

• Confirmation requires sleep testing with polysomnography, which consists of continuous measurement of arterial oxygen saturation


I. Clinical Examination• Taking a good history requires an above-

average knowledge of the discipline involved

• Recording the chief complaints is a major portion of the history taking that ultimately will assist in making the diagnosis

• It is important to know about any previous treatment. The patient may have had surgery previously and failed to attain the expected result.


Physical condition of the patient• Neck size

– A neck size greater than 40cm (16inches), regardless of gender, has s sensitivity of 61% and a specificity of 93% for having obstructive sleep apnea syndrome

– According to some authors, a neck size of 17 inches or greater for men and 15.5 inches or greater for women, indicate an increased risk for sleep apnea


Body Mass Index (BMI)• Patient’s body mass index (BMI) directly

affects the predilection for sleep apnea.• The BMI is computed by dividing the

person’s weight in kilograms (kg) by their height in meters squared (m2).

• In men, obesity is defined as a BMI of 27.8; for women, obesity is a BMI of 27.3.

• An individual with a BMI of at least 25 kg/m2 has been found to have a sensitivity of 93% and specificity of 74% for having Obstructive Sleep Apnea .


• Blood pressure must also be recorded• It is both informative and good practice to

record blood pressure at the initial visit and at subsequent visits as a means of determining potential outcomes associated with treatment.

• Another helpful tool for screening is the Epworth Sleepiness Scale


Epworth Sleepiness Scale


II. Airway Evaluation• The evaluation of the airway begins at the

tongue and proceeds into the oral pharynx. • The condition of the tongue, its size, and

related anatomic changes should be observed and noted, in a relaxed state.

• The Mallampati Score has been used in anesthesia for many years as a means of determining the difficulty of performing an intubation as the tongue increasingly seems to obstruct the airway


• It has been found that this score is also a predictor for determining severity of sleep apnea in some people.

• Friedman et al (1999) stated that patients with a Mallampati Score of III or IV are at a greater risk for sleep apnea than those with a score of I or II.


• Tonsillar size has a direct relation to the severity of sleep apnea.

• It is well recognized that increased tonsillar size reduces the airway size and can contribute to sleep-related breathing disorders.

• Tonsil size is graded on a universally recognized standard


• The size of the uvula and observations of the soft palate should also be recorded.

• In snoring, mouth-breathing, or Obstructive Sleep Apnea patients, these structures are subjected to trauma repeatedly throughout the night, causing a change in their appearance and size.

• Nasal examination - the Nasal turbinates should be evaluated to determine if those structures are contributing to nasal airway obstruction and encouraging oral breathing.


III. Temporomandibular Joint Assessment

• Preexisting TMJ findings should be noted, especially if mandibular advancement with an oral appliance is being planned.

• If an appliance is used, one with posterior support that functions as a splint may address both issues at the same time.

• Additionally, patients who are using nasal CPAP may experience jaw and subsequent TMJ problems if the mask is held too tightly or chin straps are required to hold the mouth closed to prevent leakage around the mask or mouth breathing.


• IV. Headache Status– Headache is a common finding among

patients with sleep-disordered breathing and in some instances headache may be the symptom for which the patient seeks medical attention.

– If headache is present, it is appropriate to determine if the status of the headache improves in conjunction with the management of the sleep disorder.


• V. Muscle Assessment– It is important to evaluate and determine

tenderness of the muscles of the head and neck region

– Many patients with sleep-related breathing disorders may be fatiguing the muscles of the head and neck region and have coexisting jaw, face, or neck pain. These muscles may be responsible for pain referral that is expressed as headache


VI. Polysomnography • First proposed by Holland et al 1974• A Polysomnography is a physiologic study,

usually attended by a trained technologist, performed for at least 6 hours during a patient’s normal sleep hours.

• The study records sleep staging and other physiologic variables.

• Sleep staging includes electroencephalography (EEG), electro-oculography (EOG), and electromyography (EMG).


• Other physiologic parameters and variables that may be measured include ECG monitoring, airflow, respiratory effort, gas exchange, gastroesophageal reflux, continual blood pressure monitoring, snoring, and body position.

• Video monitoring is recorded for each patient to distinguish better among potential abnormal sleep behaviors including nightmares, nocturnal seizures, or rapid-eye-movement (REM) sleep behavioral disorder


• During analysis of the Polysomnography, each episode of apnea and hypopnea is identified and counted.

• Consensus guidelines for research do not distinguish between apneas and hypopneas, defining them as events lasting at least 10 seconds, during which there is either a “>50% decrease from baseline in the amplitude of a valid measure of breathing during sleep,” or a “clear (but not 50%) amplitude reduction of a validated measure of breathing during sleep, associated with either an oxygen desaturation of 3% or an arousal.”


• The Apnea-Hypopnea Index, also known as the Respiratory Disturbance Index (RDI) is the number of apneas and hypopneas per hour of sleep.

• It is used to assess the severity of obstructive sleep apnea.

• The usual definition of slight Obstructive Sleep Apnea is an Respiratory Disturbance Index of 5-14, moderate Obstructive Sleep Apnea is an Respiratory Disturbance Index of 15 to 30, and severe Obstructive Sleep Apnea is an Respiratory Disturbance Index greater than 30.

• The apnea-hyponea index has been shown to be a reproducible measure within a patient as well as predictor of associated cardiovascular disease.


• It is now accepted that a diagnosis of clinically significant Obstructive Sleep Apnea should be accompanied by compatible signs and symptoms and not based on an arbitrary Respiratory Disturbance Index threshold.

• According to Kryger (2002) the syndrome should be defined when an index of abnormal obstructed breathing events, or arousals caused by them, exceeds a threshold in a patient with clinical features or symptoms related to the abnormal respiratory pattern during sleep


• The Polysomnography summary report usually describes the overall Respiratory Disturbance Index , the Respiratory Disturbance Index while supine, the Respiratory Disturbance Index while in REM sleep, and the lowest oxygen desaturation. Sleep architecture is displayed as a graph through the night, termed a hypnogram.


VII. Split Night Studies • To establish optimal therapeutic pressure,

Continuous Positive Airway Pressure (CPAP) usually is initiated during polysomnography in the sleep center.

• The pressure is titrated upward in small increments until apneic episodes are controlled or eliminated

• A more reliable titration to effective pressure often requires an entire night of testing and may, for some patients, require a second Polysomnography study dedicated to Continuous Positive Airway Pressure titration.


• In some cases it is possible to condense this process into one split-night Polysomnography

• During a split-night study the technologist performs a standard diagnostic Polysomnography without Continuous Positive Airway Pressure for about 2 hours.

• Continuous positive airway pressure is then initiated and titrated by the technologist to eliminate snoring and sleep apnea.

• A split-night study is especially useful after the physician has thoroughly discussed sleep apnea treatment options with the patient, and when the patient has a good idea of the nature, inconvenience, and treatment value of Continuous Positive Airway Pressure . www.indiandentalacademy.com

Limitations of Split Night Studies:• A split night protocol requires that the

technologist make the initial diagnosis based on a partial night recording.

• Another limitation of split-night studies is that apneic episodes often are more frequent or more severe during REM sleep, and REM sleep usually occurs in the latter half of the night; therefore a 2-hour initial baseline Polysomnography may significantly underestimate the baseline severity of apnea.

• Further, the effects of body position on breathing may be missed during a time-abbreviated diagnostic study.


VIII. Portable studies

• Portable sleep studies are helpful for patients who cannot easily come to the sleep center and for certain limited studies such as follow-up studies after surgery for sleep apnea

• An attended portable study is usually more costly to perform than a laboratory study because a technologist usually attends only one patient during a portable study but usually attends two patients in the laboratory


IX. Pulse Oximetry • Arterial oxygen saturation can be monitored

continuously by pulse oximetry in the emergency room, during surgery, and during Polysomnography.

• Pulse oximetry is relatively simple and reliable • Despite limitations, oximetry may be a useful

diagnostic tool over a wide range in Obstructive Sleep Apnea severity.

• Oximetry may be useful to evaluate response to treatment after surgery or airway dilator placement in patients with known Obstructive Sleep Apnea .



• A full-night polysomnography remains the standard of reliability and accuracy for diagnosing Sleep Disordered Breathing,

• Split-night testing with Continuous positive airway pressure titration or cardio-respiratory sleep studies may be most useful in patients who have a high pretest probability of Obstructive Sleep Apnea , and clinical prediction formulas may help sleep specialists identify those patients.

• Oximetry is a viable alternative in some clinical situations because of its ease of use, its reliability, and its portability.


Upper Airway Imaging


I. Acoustic reflection - Philipson 1992

• Acoustic reflection is a noninvasive imaging technique based on analyzing sound waves reflected from upper airway structures.

• The phase and amplitude of the reflected sound waves can be transformed into an area-distance relationship by calculation of upper airway area as a function of distance from the incisors in the mouth.

• The technique is generally performed through the mouth, is free of radiation, and because it is both fast (images can be obtained at 0.2 second intervals) and reproducible, permits dynamic imaging of the upper airway.


• Unfortunately, acoustic reflection does not provide information on airway structure or geometry

• Moreover, measurements are usually performed in the sitting position with an oral mouthpiece.

• Mouthpieces present difficulties for the examination of upper airway anatomy because opening the mouth alters upper airway geometry

• Accordingly, acoustic reflection may not be comparable with other modalities in which the mouth is closed during imaging.

• Acoustic reflection thus far has been used primarily as a research tool.


II. Fluoroscopy• Fluoroscopy has also been used to study upper

airway closure in patients with sleep apnea.• Fluoroscopic studies during sleep have

demonstrated that upper airway closure occurs in the retropalatal region for most patients with sleep apnea.

• Although fluoroscopy can provide a dynamic evaluation of the upper airway during wakefulness and sleep, radiation exposure makes this study impractical for routine use.


III. Nasopharyngoscopy • Nasopharyngoscopy is commonly used to

evaluate the nasal passages, oropharynx, and vocal cords.

• Although it is invasive, nasopharyngoscopy is easily performed and does not involve radiation exposure.

• Moreover, it permits direct observation of the dynamic appearance of the pharynx.

• However, it examines only the lumen of the upper airway and does not provide measurement of the surrounding soft tissue structures.


• The utility of nasopharyngoscopy in evaluating the upper airway seems to be increased if a Muller’s maneuver is performed during the examination.

• The Muller’s maneuver is a voluntary inspiration against a closed mouth and obstructed nares.

• It is thought to simulate the upper airway collapse that occurs during an apnea.

• Although the degree of obstruction on negative inspiration with a Muller’s maneuver is not a direct correlate of the site of upper airway collapse during sleep, Muller’s maneuver has been shown to add important information on possible sites of obstruction.


III. Cephalometry• This technique is widely available, easily

performed, and much less expensive than either CT scanning or MR imaging

• Cephalometrics have also been used to evaluate skeletal structures before facial surgery (mandibular advancement, bimaxillary advancement, sliding genioplasty) and to evaluate the efficacy of oral appliances

• Cephalometry is considered useful for evaluating and quantifying craniofacial (mandibular and hyoid position) and soft tissue structures (tongue and soft palate) in patients with retrognathia or micrognathia www.indiandentalacademy.com

• Nonetheless, the low cost and widespread availability of Cephalometrics make it useful for sleep apnea patients being treated with oral appliances and undergoing craniofacial surgery.


IV. Computed Tomography• Computed tomographic scanning is widely

available and is ideal for imaging the lumen of the upper airway because it accurately measures the cross-sectional area.

• Computed tomography also provides excellent resolution for upper airway soft tissue and craniofacial structures.

• Three-dimensional volumetric reconstructions of upper airway, soft tissue, and bony structures can be obtained

• Dynamic imaging of the upper airway can be performed with electron beam CT


• Compared with MR images, however, CT scanning has limited soft tissue contrast resolution, particularly for upper airway adipose tissue.

• In addition, CT scanning is relatively expensive and exposes the patient to radiation.

• The radiation exposure particularly limits state-dependent imaging and studies that require repeat scanning.

• Despite these limitations, studies using CT scanning have led to important insights into the pathogenesis of airway closure in patients with obstructive sleep apnea.


V. Magnetic Resonance Imaging • MR imaging is perhaps the most useful imaging

technique for studying obstructive sleep apnea because it:– Provides excellent resolution of upper airway and soft

tissue (including adipose tissue), – Accurately measures cross-sectional airway area and

volume,– Allows imaging in the axial, sagittal, and coronal

planes– Provides data suitable for three-dimensional

reconstructions of upper airway soft tissue and craniofacial structures

– Can be performed during wakefulness and sleep, and does not expose subjects to radiation.


• MR imaging, however, is expensive and is not available in all hospitals.

• Further, MR studies cannot be performed on patients with ferromagnetic implants or pacemakers, patients who weigh more than 300 pounds, or patients who are claustrophobic (a relative contraindication).

• Moreover, Suto et al, (1993) reported that achieving sleep in the MR scanner is difficult because of the associated noise.


Clinical utility of upper airway imaging

• Upper airway imaging is not indicated in routine diagnostic evaluation of most patients with obstructive sleep apnea

• Imaging of the airway is also not indicated in patients with sleep apnea treated successfully with Continuous positive airway pressure .

• MR imaging and nasopharyngoscopy are the imaging modalities of choice in patients undergoing a Uvulopalatopharyngoplasty.

• Cephalometrics should be considered in patients being treated with mandibular repositioning devices.

• In patients undergoing maxillomandibular advancement surgery or sliding genioplasty, CT scanning with three dimensional reconstructions and cephalometrics may be indicated. www.indiandentalacademy.com

Management of Obstructive Sleep Apnea


• The treatment of Obstructive sleep apnea depends on several factors such as the severity of the symptoms, site of airway obstruction, and co-operation of the patient.

• There are several modalities ranging from simple lifestyle measures such as weight loss and avoidance of alcohol, to more substantial measures such as continuous positive airway pressure, or oral appliances, and in more severe cases, even surgical intervention.


NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE

• Nasal continuous positive airway pressure (N-CPAP) is a highly effective and safe treatment for obstructive sleep apnea and is generally considered to be the current primary treatment of obstructive sleep apnea

• Sullivan et al (1981) first reported the use of nasal continuous airway pressure for obstructive sleep apnea in adults. Their device consisted of intranasal tubes attached to a blower unit.

• Sanders et al (1983) introduced the nasal mask delivery system, which made continuous positive airway pressure more user-friendly.


• Fundamentally, the application of a therapeutic level of continuous positive airway pressure results in immediate relief in the upper airway obstruction.

• This benefit has been attributed to the continuous positive airway pressure functioning as a pneumatic splint for the upper airway.

• Additional physiologic benefits of continuous positive airway pressure application to include improvement in the function of pharyngeal dilator muscles, ventilator drive, and upper airway morphology


Nasal continuous positive airway pressure Apparatus

• It consists of an inspiratory limb, which uses compressed air from a standard hospital wall source regulated by a flow meter.

• To prevent mucosal drying, a humidifier containing a one-way valve is used which ends in the nasal mask.

• The expiratory flow limb begins at the mask and ends with a threshold water column positive end expiratory pressure (PEEP).

• The level of Nasal continuous positive airway pressure could then be adjusted by manipulating the amount of flow and the level of water in the PEEP column.


Nasal continuous positive airway pressure Apparatus


Benefits of Nasal continuous positive airway pressure therapy

• Patient’s perceived quality of life increases • Interestingly, the spouses of obstructive sleep apnea

patients also gained from this therapy • Reduced sleepiness and the improved ability to steer a

motor vehicle and hence frequency of driving accidents were reduced

• Health-related quality of life of obstructive sleep apnea patients improves with long-term continuous positive airway pressure treatment

• Randomized placebo-controlled studies demonstrated a reduction in blood pressure levels with continuous positive airway pressure therapy.

• Reduces long-term morbidity and mortality from cardiovascular causeswww.indiandentalacademy.com

Disadvantages of Nasal continuous positive airway pressure therapy

• While current effective management of moderate to severe sleep apnea is still largely dependent on nasal continuous positive airway pressure , the process is still cumbersome

• Approximately 10-50% of subjects find the continuous positive airway pressure (CPAP) intolerably uncomfortable and discontinue its use with in a short period of time.


• Inspiration is facilitated and expiration is impeded, a new balance between inspiratory muscle effort and lung elastic recoil is established.

• This results in the following:– Reduced cardiac output and renal function.– Increased pressure in the sinus, which might

decrease drainage and cause problems in patients with preexisting abnormalities.

– Drying of the airway mucosa is another complication, which can be overcome by the inclusion of a humidifier in the circuit.


• Mechanical failure of continuous positive airway pressure – occlusion of the exhaust line could theoretically cause hyper-inflation of the lungs and perhaps even lung rupture. This does not happen if a low pressure pump is used.

• Since the pressure is applied through the nose, the mouth will act as a blow-off valve and result in reduction of the pressure. When this happens, the patient will go back to his usual state of upper airway obstruction. This is prevented by using face-masks covering both the nose and the mouth.


Auto Nasal continuous positive airway pressure

• The device continuously adjusts the applied air-pressure to an optimum level throughout the night and appears to improve compliance.

• Upper airway resistance is influenced by many dynamic factors that may change, such as body position, sleep stages, sleep deprivation, body weight and fluctuations of nasal congestion.

• Therefore, a single pressure level, as with standard continuous positive airway pressure could result in insufficient air pressure at certain times, particularly after alcohol consumption.


• Auto continuous positive airway pressure is expected to become more popular in the future as it facilitates the initiation and follow up of the treatment, especially the process of optimal initial pressure titration, and the elimination of repeated titrations over prolonged years of therapy.


ORAL APPLIANCES IN THERAPY OF OBSTRUCTIVE

SLEEP APNEA


• Although Nasal continuous positive airway pressure is a logical first step, some patients cannot tolerate Nasal continuous positive airway pressure, creating a demand for alternative non-surgical treatment modalities.

• Dental devices were being promoted as an alternative conservative, noninvasive modality for management of some patients with mild Obstructive Sleep Apnea symptoms and those subjects who have a history of disruptive snoring


Classification of Oral Appliances• Dental appliances in the treatment of

Obstructive Sleep Apnea can be divided into three categories:1. One type of appliance is designed to reposition the

tongue in a more forward position (Tongue retaining device).

2. A second type of devices positions the mandible forward. The rationale for this movement is that the tongue is attached to the genial tubercles of the mandible and positioning the mandible forward moves the tongue forward. These mandibular repositioning appliances also change hyoid bone position and modify the lower airway space below the level of the base of the tongue.


3. The third type of intra oral device is designed to lift the soft palate or reposition the uvula (equalizer). The rationale for the use of palate lifting devices is to reduce the vibration of the soft palate that causes the snoring sound.


Tongue retaining devices • The Tongue retaining devices is a custom-made

appliance designed to allow the tongue to remain in a forward position between the anterior teeth by holding the tongue in an anterior bulb with negative pressure during sleep.

• Tongue protrusion increases the oropharyngeal, velopharyngeal and hypopharyngeal cross-sectional areas of the upper airway, thereby improving airway patency and function and reducing the airflow resistance


• The advantages of tongue retaining devices over mandibular advancement devices are as follows:– They can be used on edentulous patients,

whereas the latter need ample dentition for retention purposes.

– They do not loosen restorations.– They require minimal or no adjustments.– They cause minimal sensitivity in teeth or in

the TMJ. www.indiandentalacademy.com

• The effectiveness of Tongue retaining devices in Sleep apnea subjects may be partially related to the forward tongue posture that compensates for the altered Genioglossus muscle activity.

• Tongue-retaining devices appear to be effective in over 75% percentage of the mild to moderate cases of obstructive sleep apnea.

• Compared to the most commonly performed non-surgical treatment (continuous positive airway pressure ), the Tongue-retaining devices is more easily tolerated and has fewer long-term compliance problems.



Mandibular Advancement Devices


• In 1934, Pierre Robin first described the concept of advancing the mandible with a monobloc functional appliance to treat airway obstruction in infants with micrognathia.

• His method was not accepted and it was not until 1985 that Meier-Ewert next described an intra-oral protraction device for the treatment of sleep apnea.

• In general, MAD’s consist of form-fitting trays that fit over the maxillary and mandibular teeth


• They may be fixed-position with no allowance for adjustability for advancement or retrusion of the mandible, or may be adjustable

• Adjustable oral appliances are generally preferred because they can be adjusted in an antero-posterior position until an acceptable level of symptom improvement has occurred, while teeth or temporomandibular joint sensitivity is controlled.

• Some oral appliances may be made from a pre-fabricated standard set, similar to alginate impression trays and can be fabricated chair side in the clinical setting.

• Others must be custom fabricated on a set of casts by a laboratory


Designs of Mandibular Advancement Devices

• Removable Activator type Mandibular Advancement Device– Every posterior tooth has full

occlusal coverage with acrylic.– All anterior teeth were capped

on the incisal, lingual, and labial surfaces by acrylic.

– Openings were cut through the acrylic between the maxillary and mandibular arches to allow respiration if the subject developed nasal congestion


• Anterior Mandibular Positioner– The oral appliance

consisted of a titanium hinge with 5 adjustment holes that connected full-coverage upper and lower, hard acrylic splints.


• The Karwetzky activator : Rose et al (EJOS 2002) – Passive tooth-and tissue

borne device – It is a bimaxillary, tooth- and

tissue-borne activator with a loose fit.

– The activator is divided along the occlusal plane.

– Two U-loops are fixed in the lingual acrylic in the area of the first molars, allowing sagittal adjustment of the mandibular protrusion.

– This design permits lateral and vertical jaw movements during sleep www.indiandentalacademy.com

• Intra oral sleep apnea device (ISAD)– It consists of two thin

thermoplastic splints, worn on the upper and lower jaws, connected by two adjustable telescopic guide rods.

– It works by advancing and slightly depressing the mandible and tongue while imparting a slight vertical clockwise rotation.


Adjustable Herbts appliance


• Magnetic appliances for treatment of OSA– Inherent magnetic forces directly transfer

active forces to the jaws and thereby constrain the lower jaw in a forward position.

– During sleep, when the masticatory muscles are physiologically relaxed, there is an obvious risk that the mandibular complex moves backward and closes the airflow in the upper airway space.

– In such situations, a magnetic appliance may be more effective than the conventional passive functional appliance, because the magnet forces prevent the closing by providing direct and continuous mandibular advancement.



• The following advantages of the magnetic appliance were enumerated:– The inherent magnetic forces constrain the lower

jaw directly in an advanced position even during sleep when the masticatory muscles are relaxed.

– It is less bulky than the conventional monoblock type and allows freedom of function and, consequently, patient compliance is improved.

– If there is a need to change the advanced position of the mandible, this can easily be done by changing the positions of the magnets in the splints.


• One shortcoming of the rare earth magnets, particularly the neodymium-iron-boron alloy, is that the alloy is very susceptible to corrosion assault by the saliva. – When a magnet corrodes, there is

considerable risk of destroyed magnetic properties and loss of force. Furthermore, there is a risk of liberation of cytotoxic components


• The Modified Monobloc: Cozza ( JCO 2004)

– The device was fabricated from clear acrylic resin, with full tooth coverage in both arches and a central screw.

– The incisal edges and superior labial surfaces of the mandibular incisors were capped to prevent tipping.

– The construction bite positioned the mandible anteriorly into an edge-to edge incisal relationship, with a vertical bite opening of 2-3 mm.

– A Tucat’s Pearl sliding on a wire in the anterior lingual portion of the appliance was added as reference point for anterior positioning of the tongue. www.indiandentalacademy.com

• Chrome-cobalt mandibular advancement devices: Ash and Smith ( JO 2004)– They emphasized the physical weakness of

conventional mandibular advancement devices, which normally are made of acrylic, or may have a stainless steel shaft and piston fixed linkage mechanism,

– These parts are subject to considerable forces and may undergo fracture.

– The chrome cobalt advancement devices are fabricated according to the principles of prosthetic dentistry, with surveying of stone models for construction of the chrome cobalt framework.

– Clasps are incorporated for additional retention in both the upper and lower appliances.


• The advantages of the appliance were its superior strength, reduced bulk, kindness to soft tissues, and enhanced retention and stability.

• The possible disadvantages include financial cost, additional clinical and laboratory stages, and the need for a new appliance if the patient experiences tooth loss.


• The Glasgow approach – Simple one-piece mandibular advancement device

using a semi-soft material. – The advantage of this appliance was that it placed no

restriction on the dental status of the patients accepted for treatment.

– Softened impression compound placed between the anterior teeth is used to obtain the protrusive jaw position, following which, aluminium impregnated wax is pressed around the buccal surfaces of the teeth and the impression compound.

– The appliances are made with polyvinyl acetate polyethylene, 4mm thick and trimmed to shape.

– They are then placed on the articulator and joined together.


• Advantages – simplicity and low cost of

this appliance compared with other treatment options.

• Disadvantages – longevity has been

questioned and would require a replacement after 12-18 months

– Other side effects like hypersalivation


Hans et al AJO 1997

• Device designed to increase vertical dimension and protrude the mandible (device A).

• Device designed to minimally increase vertical opening without protruding the mandible (device B).

• Device A reduced RDI scores in 9 of 10 subjects

• Device B showed no change or an increased RDI score in 8 of 8 subjects.

• Subjects who showed no improvement with device B were then fitted with device A.

• Four of those seven subjects showed a reduction in RDI


Randomized controlled trials comparing Oral Appliances with CPAP

• Ferguson et al (1996) – They compared one-piece, hard acrylic,

nonadjustable oral appliance, Snore Guard to continuous positive airway pressure in patients with mild to moderate obstructive sleep apnea.

– It was found that the treatment of 48.5 % of SnoreGuard and 62% of continuous positive airway pressure patients was considered successful.

– While patients preferred the SnoreGuard treatment to the continuous positive airway pressure therapy, the former was not as effective as was the continuous positive airway pressure treatment in relieving symptoms of excessive daytime sleepiness. www.indiandentalacademy.com

• Randerath et al (2002) – Compared the effectiveness of an individually

adjustable intra oral sleep apnea device (ISAD) with that of continuous positive airway pressure .

– The intra oral sleep apnea device reduced snoring in the long term, but significantly improved the RDI only in the early phase of treatment.

– In contrast, continuous positive airway pressure normalized RDI, snoring and arousals throughout the entire treatment period.


• They concluded that in patients with mild to moderate obstructive sleep apnea, continuous positive airway pressure is superior to treatment with mandibular advancement device.

• However, as one third of patients respond sufficiently to treatment with the intra oral sleep apnea device , in patients who refuse continuous positive airway pressure , the use of mandibular advancement devices should be considered.


• Ferguson et al (2006) – Conducted an evidence-based review of literature

regarding the use of oral appliances in the treatment of snoring and obstructive sleep apnea syndrome from 1995

– In comparison to continuous positive airway pressure, oral appliances are less efficacious in reducing the apnea hypopnea index (AHI), but oral appliances appear to be used more (at least by self report), and in many studies were preferred over continuous positive airway pressure when the treatments were compared.


Randomized controlled trials comparing different designs of oral appliances

• Lawton, Battagel and Kotecha (EJO 2005) – They analyzed the efficacy of the Twin Block in relation

to the Herbst appliance as a mandibular advancement splint (MAS).

– The results suggested that there was no difference in the treatment performance of the Twin Block and Herbst for AHI , snoring frequency, arterial blood oxygen saturation, quality of life and side-effects.

– The Herbst proved to be the more effective appliance for reducing daytime sleepiness and was the more popular appliance among the patients.

– The Twin Block appliance is bulkier than the Herbst and it may be that the additional reduction in airway volume was enough to negate the positional benefits of the appliance


• Bloch et al (2000) – Studied the effectiveness and side effects of

an adjustable Herbst appliance with those of a fixed single-piece mandibular advancement device (Monobloc) with equal advancement.

– This project was one of the first to compare the effectiveness of mandibular advancement devices with different designs.

– Patient preference and trends of polysomnographic data showed the Monobloc to have greater patient acceptability and to be more effective than the Herbst appliance in the treatment of obstructive sleep apnea .


Clinical aspects of insertion and titration of oral appliances

• General technique for oral appliances that are selected from a prefabricated set– The oral appliance that incorporates thermoplastic

material is initially heated in warm or hot water – Once the thermoplastic material is softened, the oral

appliance is inserted, and any excess thermoplastic material is adapted to the buccal and lingual surfaces of the teeth using the fingers.

– The oral appliance should be removed and reinserted several times as the material chills to prevent it from becoming locked into undercut areas.


• Titration of oral appliances – It consists of slowly moving the mandible

either anteriorly or posteriorly using the adjustable mechanism until successful results are achieved with the minimum possible protrusive position.

– The titration of oral appliances may be tedious, requiring several weeks to months.

– Once completed, titration may become necessary again at some future time if sleep disorder symptoms recur or tooth or temporomandibular joint sensitivity appear.


• The following titration process is for a device with a screw-type mechanism:– The patient generally begins with the mandible

advanced to 70-75% of his or her maximum protrusive position relative to the most retrusive position.

– The oral appliance is inserted and not titrated for several days until the patient has become accustomed to wearing the appliance.

– If, as frequently happens, successful results are achieved, titration is not necessary.

– If the symptoms have not been reduced acceptably, the mandible is slowly protruded, often in increments of 0.25 mm per night.


• After approximately 2 weeks, the patient must be re-examined if the desired results have been achieved.

• If the patient reports sensitive teeth, it may be necessary to adjust the oral appliance around the sensitive teeth.

• Teeth or Tempromandibular joint sensitivity may also require that the mandible be slowly retruded until the problem is addressed.

• Once the sensitivity is corrected, it may be necessary again to protrude the mandible until the sleep disorder symptoms are addressed.

• If the obstructive sleep apnea has worsened, the patient is not allowed to continue with the oral appliance therapy.


Treatment Considerations • Clinicians should explain the possible side

effects of treatment including the possibility that the appliance may loosen or break dental restorations, excess salivation, xerostomia, TMJ pain, soreness of the masseter muscle, and tooth discomfort

• Mandibular protrusion devices should only be used when a patient has at least 8 teeth in each arch and is able to demonstrate a mandibular protrusion of at least 5 mm and a bite opening of greater than 25 mm.

• Totally edentulous patients are usually not good candidates for mandibular repositioners, but tongue-retaining devices may be used in edentulous patients for snoring, and not obstructive sleep apnea . www.indiandentalacademy.com

• Patients who are treated with a mandibular protruding device for obstructive sleep apnea may find that when they wear the appliance, their occlusion feel different for a short while after the appliance is removed

• Obstructive sleep apnea patients who present with more severe TMJ pain are probably not good candidates for treatment with mandibular protrusion devices.

• Patients with significant bruxism can frequently damage mandibular protrusion devices and thus make this treatment approach costly and inefficient,

• While very obese patients, with some exceptions, are best treated by other means than mandibular protrusion.


Amount of bite opening• As the mouth opens, the anterior attachment of

the tongue swings not only down but also backward carrying the tongue toward the airway.

• For this reason, L’Estrange et al (1997) concluded that Mandibular Advancement Device should keep jaw opening to an “absolute minimum

• Meurice et al (1996), concluded that pharyngeal airway was more likely to obstruct when the mandible opened 15 mm at the incisors

• There are no published polysomnographic studies that establish the optimum vertical dimension for the Mandibular Advancement Device

• The most commonly selected bite opening is about 2 mm between the incisors www.indiandentalacademy.com

• Vicomi et al (1988) showed good apnea reduction with an Mandibular Advancement Device that advances the mandible 6 to 9 mm while opening it vertically 17 mm.

• Mandibular Advancement Device expand the airway not only behind the tongue but also behind the soft palate.

• The mechanism for this velopharyngeal expansion is the pull on the palatoglossus muscle


• The superior pharyngeal constrictor muscle attaches directly and indirectly to the mandible.

• Opening the mouth, therefore, exerts a downward force on the lateral walls of the pharyngeal airway, stretching them longitudinally.

• This stretching improves airway patency by reducing folds, compliance and extrinsic compression.

• Another advantage of increasing the jaw opening beyond 2 mm is that it helps part the lips allowing a passage for oral breathing.


SURGICAL MANAGEMENT OF OSA


• Surgical management of Obstructive sleep apnea is generally recommended when the applicable conservative therapies are unsuccessful or not well tolerated, as well as or patients who have an identifiable underlying surgically correctable abnormality that is causing the Obstructive sleep apnea .

• Surgery can provide definitive treatment, thus eliminating patient compliance issues, but only if performed competently, both in terms of technical skill and on the correct site or area of upper airway obstruction.


Presurgical Evaluation • The upper airway can be divided into

three main regions for evaluation• Nose and Nasopharynx

– The nose should be evaluated for septal deviation, turbinate hypertrophy, nasal polyps, infectious and edematous conditions such as rhinosinusitis, rhinitis and neoplasms, as well as patency of internal nasal valve.

– The nasopharynx is examined for adenoid hypertrophy, polyps, cysts, and obstructing masses.


• Oral Cavity and Oropharynx– The tongue is estimated to be of normal size if it

sits at or below the level of the occlusal plane at rest. It is subjectively described to be mildly, moderately or severely enlarged if above the occlusal plane

– The position of the soft palate with respect to the tongue is noted at rest and is graded using the modified Malampatti Score, I through IV

– The pharyngeal tonsils are graded 1,2,3 or 4, dividing the airway into less than 25%, 25 to 50%, 50-75% or greater than 75% respectively


• The hypopharynx and larynx– The hypopharynx and larynx are best

evaluated from above with the flexible endoscope.

– The base of the tongue, epiglottis, vocal folds, arytenoids and the presence of lingual tonsils are noted


• The current surgical procedures used for Obstructive sleep apnea are – Tracheostomy,– Uvulopalatopharyngoplasty, – Laser assisted uvulopalatoplasty, – Surgical reduction of the tongue, – Mandibular osteotomy with genioglossus

advancemnt, – Hyoid myotomy and suspension, as well as

maxillomandibular advancement


I) TRACHEOSTOMY FOR THE TREATMENT OF OSA

• Before the introduction of uvulopalatopharyngoplasty and continuous positive airway pressure, tracheostomy was the only treatment available.

• At present this procedure is usually reserved for the most severe Obstructive sleep apnea patients

• It is 100% effective in alleviating Obstructive sleep apnea by bypassing all upper airway obstructive sites

• Tracheostomy has been shown by several authors to reduce mortality in patients with sleep apnea


Indications of tracheostomy in patients with Obstructive sleep apnea

• Disabling sleepiness with severe familial and socioeconomic impact.

• Severe cardiac arrhythmias associated with respiratory events.

• A high apnea index. (> 60).• Notable oxygen desaturation level during sleep

i.e. oxygen desaturation level below 60%.• No improvement of clinical symptoms or

polysomnography findings after medical trials.• Tracheostomy may also be performed to protect

the airway from obstruction due to edema while the patient undergoes upper airway reconstructive surgery


II) UVULOPALATOPHARYNGOPLASTY For Obstructive sleep apnea

• In 1979, Fujita et al began to look for alternatives for tracheostomy for the treatment of patients with obstructive sleep apnea.

• In 1980 they introduced a new operation for the correction of anatomic abnormalities in the pharynx, which was referred to as a Uvulopalatopharyngoplasty

• This is designed to decrease oropharyngeal collapsibility by reducing the soft palate, uvula, posterior and lateral pharyngeal walls, and tonsils when present.

• The goals of surgery are to resect the posterior margins of the soft palate and redundant lateral pharyngeal wall mucosa


• The soft palate resection ranges from 8-15 mm, stopping short of the thick muscular part of the palate.

• The lateral pharyngeal wall is treated by resecting redundant mucosa and developing a flap along the posterior wall.

• The flap is advanced and sutured to the anterior tonsillar pillar area www.indiandentalacademy.com

Complications of Uvulopalatopharyngoplasty

• Early complications: – Transient velopharyngeal incompetence.– Wound dehiscence.– Hemorrhage.– Wound infection

• Late complications: – Pharyngeal discomfort, dryness, tightness– Postnasal secretion– Inability to initiate swallowing– Prolonged sore throat– Taste disturbance– Speech disturbance– Permanent velopharyngeal incompetence– Nasopharyngeal stenosis.www.indiandentalacademy.com

III. LASER ASSISTED UVULOPALATOPLASTY (KAMAMI

TECHNIQUE) • Kamami (1990) first described laser assisted

uvulopalatoplasty (LAUP) for the treatment of snoring

• Laser assisted uvulupalatoplasty stiffens and possibly enlarges the antero-posterior retopalatal airway and is associated with an extremely low complication rate when compared with Uvulopalatopharyngoplasty

• The technique can be performed under local anesthesia as a multiple out-patient procedure.

• The laser usually used is CO2 laser at 20 watts in continuous mode.


• The key disadvantages with laser assisted uvulopalatoplasty are however the early drop off in the success rate and the severe degree of post-operative pain encountered

• One of the biggest disadvantages of the laser assisted uvulopalatoplasty procedure from the physician’s point of view has been the high cost of the equipment.


IV. SURGICAL PROCEDURES FOR THE TONGUE

• Midline glossectomy – A laser midline glossectomy is accomplished

by vaporizing a 2 cm by 5 cm rectangular portion or the midline tongue with a laser.

– A lingual tonsillectomy, reduction of aryepiglottic folds, and a partial epiglottectomy can be done concomitantly if indicated

– Complications of this procedure include bleeding, dysphagia and altered taste


• Linguloplasty– The linguloplasty differs from the laser midline

glossectomy in that the tongue excision is extended more posteriorly and laterally.

– The defect is closed, by suturing the posterior margin anteriorly, which advances the tongue base anteriorly.

– The anterior rotation of the posterior margin significantly improves the success rate to around 77%


Tongue-base suspension sutures: (Coleman and Bick, 1999)

• A non-resorbable suspension suture is placed in the tongue and is then attached to a titanium bone screw inserted into the geniotubercle of the posterior aspect of the mandible.

• The suture tension prevents posterior tongue displacement and occlusion with the posterior pharyngeal wall www.indiandentalacademy.com

V. INFERIOR SAGITTAL OSTEOTOMY OF THE MANDIBLE

• This method allows isolated advancement of the genial tubercle and genioglossus muscle

• The surgical approach to the mandible is through the submental incision.

• A rectangular osteotomy is accomplished around the geniotubercle on the labial surface of the anterior mandible.

• It is desirable to leave 8-10 mm of inferior border to decrease the chance of fracture.

• The genial segment with its genioglossus attachment is advanced, rotated and rigidly fixed to the mandible www.indiandentalacademy.com

Inferior sagittal osteotomy of mandible


VI. MAXILLOMANDIBULAR ADVANCMENT SURGERY

• Maxillomandibular advancement or MMA surgery, anteriorly repositions the maxillary and mandibular framework and their attending muscular attachments.

• It pulls forward the anterior pharyngeal tissues attached to the maxilla, mandible and hyoid to structurally enlarge the entire velopharynx,

• As well as to enhance the neuromuscular tone of the pharyngeal dilator muscles via an extra-pharyngeal operation


• Procedure:– The maxillary surgery performed is a standard

LeFort I osteotomy which is advanced 10-14 mm and stabilized with rigid internal fixation.

– Bone grafts are required to fill in the gaps created by the large advancement.

– The mandible is advanced 10-14 mm by a bilateral sagittal split osteotomy and stabilized with rigid internal fixation with bicortical screws.

– Additional maxillomandibular skeletal fixation can help prevent skeletal relapse.


VII. DISTRACTION OSTEOGENESIS FOR TREATMENT OF OSAHS

• Advantages:– It eliminates the need for bone grafting, which is

usually required when large amounts of skeletal advancement are performed

– It involves less surgical dissection because the lengthening is the result of natural bone healing in a gap created by a simple osteotomy.

– The incremental skeletal movement allows accommodation of the soft tissues, thus enabling large skeletal movement that cannot be achieved by conventional techniques.

– The improved soft tissue accommodation also improves the stability of the new skeletal position.www.indiandentalacademy.com


• Disadvantages:– Although less surgical dissection is

necessary, procedure is highly technique sensitive. Parallelism of the distraction vectors is extremely important to avoid malocclusion. This can be quite difficult in simultaneous maxillo-mandibular advancement with 4 distraction devices.

– The most significant disadvantage for distraction osteogenesis in the treatment of sleep apnea in adult patients is the length of treatment time (may take up to 4 months)

– The weakness of regenerated bone and the presence of distraction devices and arch bars significantly affect the patient’s mastication and speech.


Conclusion • In rapidly industrializing country like India, with

soaring rates of obesity, it is quite likely that prevalence of Obstructive Sleep Apnea is far higher than detected and rising rapidly

• Although this disease traditionally thought to affect mainly middle aged obese person of male sex, over recent years there has been increasing evidence of occurrence of this disease in persons with certain craniofacial structures and female sex

• The Orthodontist, in concert with trained medical personnel can render valuable service in diagnosis and treatment of OSA


• At present there are several mandibular advancement appliances, which has been shown to enjoy high compliance rates and achieve excellent resolution of symptoms

• It is important however for these patients to undergo regular medical referrals to monitor their condition and switch to an alternative treatment plan if required

• Thus, there can be no doubt that Orthodontist has a vital role to play in identifying as well as treating OSA patients

• It would thus be important for Orthodontist to make themselves aware of the procedures and responsibilites involved in multi-disciplinary management of OSA


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Documents

Obstructive Sleep Apnea- Dr.M.M.varadharaja / orthodontic courses by Indian dental academy