INTRA ORAL APPLIANCES IN SLEEP APNOEA. SEMINAR ALONG WITH SOME ARTICLES

1. ROLE OF MANDIBULAR
ADVANCEMENT APPLIANCES IN
SLEEP APNOEA AND SLEEP-RELATED
BREATHING DISORDERS
Niraj kumar
(Junior resident)
Maxillofacial prosthodontics
AIIMS-NEW DELHI

2. Introduction
- Sleep apnoea is a sleep disorder characterized by
- pauses in breathing , or
- periods of shallow breathing during sleep.
- Each pause can last for a few seconds to several minutes and
they happen many times a night.

3. - most common form - loud snoring.
- choking or snorting sound as breathing resumes.
- disrupts normal sleep
- those affected are often sleepy or tired during the day.
- affects 1-6% of adults and 2% of children.
- M:F (2:1)
- most commonly (55-60years)

4. Signs and symptoms
- excessive daytime sleepiness (EDS) and impaired alertness.
- executive functioning - the way the person plans and
initiates tasks.
- paying attention, working effectively and processing
information when in a waking state.
- using memory and learning.

5. Risk factors
Sleep apnoea can affect people regardless of sex, race, or age.
- however, risk factors include:
- being male
- excessive weight
- age above 40
- enlarged tonsils or tongue
- small jaw bone
- family history of sleep apnoea
- deviated septum

6. - alcohol, sedatives and tranquilizers may also promote sleep
apnoea by relaxing throat muscles.
- smokers have sleep apnoea- 3 times the rate of people who
have never smoked.

7. Mechanism
When breathing is paused
carbon dioxide builds up in the bloodstream
chemoreceptors in blood note the high carbon dioxide levels.
brain signals to wake the person and start breathing normally
restores oxygen levels and the person falls asleep again.

8. Diagnosis
- sleep apnea may be diagnosed by the
evaluation of symptoms, risk factors and
observation, (excessive daytime sleepiness and
fatigue) but the gold standard for diagnosis is a
formal sleep study (polysomnography).

9. Polysomnography
Polysomnography (PSG), a type of multi-parametric test used in
the study of sleep and as a diagnostic tool in sleep medicine.
-test result is called a polysomnogram.
The PSG monitors many body functions including:
- brain (EEG),
- eye movements (EOG),
- muscle activity or skeletal muscle activation (EMG) and
- heart rhythm (ECG) during sleep.

11. Apnoea-hypopnea index (AHI)
apnoea - complete cessation – airflow -10 sec.
hypopnea - decrease airflow - 50% - 10 sec.
- AHI is calculated by dividing the number of apnea
events by the number of hours of sleep.
- values are categorized as:
• Normal: 0-4
• Mild sleep apnea : 5 - 14
• Moderate sleep apnea: 15-29
• Severe sleep apnea: 30 or more
PREFFERED GROUP FOR
TREATMENT WITH
INTRAORAL APPLIANCES

12. Management
Surgical
therapy
Non-surgical
therapies
-tracheostomy
-nasal surgeries
-maxillofacial surgery
-base of tongue resection
-hyoid repsitioning
-pharyngeal surgeries
-eliminating aggravating factors
-stimulation of upper airway
-pharmacological therapies
-CPAP
-INTRA-ORAL APPLIANCES
-tongue retaining devices
-mandibular advancement splints

13. - Before treating a snoring problem, dentists
should require the patient to complete an Epworth
Sleepiness Scale, or (ESS).
- questionnaire used to determine the likelihood
of dozing off in a variety of common daily situations.
Epworth Sleepiness Scale (ESS)

15. - scores on the ESS can range from 0 to 30.
- subjects scoring 10 or higher on the scale are
considered hypersomnolent
referred to an appropriate
medical center.

16. Intra-oral appliances
-two appliance categories have been documented as
being effective in this therapy:
a) tongue-retaining devices, which retain the
tongue anteriorly by means of an
extra oral suction bulb, and
b) mandibular advancement devices (MADs)
-which retain the mandible
anteriorly by means of dental
anchorage.

17. Extra oral suction bulb

18. Mandibular advancement devices
(MADs)
- MADs are constructed in a manner and with material
that secures the mandible in its optimum position.
- the optimum mandibular position needs to be captured
and transferred to the articulator with an accurate
construction bite.

19. - therefore, dentists must consider the efficacy
and the safety of an MAD when selecting an
appliance.
- since occlusal shifting appears to be the
main potential detrimental effect,
- dentists should consider all available
means to monitor and minimize these
changes.

20. CONSTRUCTION BITE
- the position in which a nonadjustable MAD holds
the mandible is determined by the construction bite.

21. - before selecting the parameters of the
construction bite, the dentist must carefully
weigh the advantages and disadvantages of
each
each degree of
mandibular downward
rotation.
- millimeter of
mandibular forward
translation
&

22. a) forward mandibular translation - provides
beneficial longitudinal and sagittal stretching of the
pharyngeal airway;
- however, each millimeter of forward movement
increases the forces applied against the teeth and in
the TMJ.

23. - These forces may alter the occlusion by :
- changing the angulation of the teeth,
- remodeling the condyle and fossa, and
- shortening the inferior lateral pterygoid
muscle.
therefore; mandibular advancement of about
70 % of the protrusive path
- has been shown to be effective in reducing SDB
symptoms with minimal occlusal changes.

24. b) downward mandibular rotation - provides
beneficial longitudinal stretching, but
also causes detrimental backward compression
of the pharyngeal airway.

25. - therefore ; 5 mm appears to be a good
compromise, for vertical opening since that
amount of opening would give :
- a sufficient vertical raise ,
- without any compression of the
airway in the pharyngeal region.

26. - once the desired parameters for the
construction bite are selected, they can be
captured and transferred to an articulator
with the use of a George Gauge.
Horizontal
component
Vertical
component

27. - patient closing into preset incisal notches,
registering the desired anteroposterior and vertical
mandibular position in impression material on a
bitefork.

28. - more than 55 different appliances are available
to dentists and this number continues to increase.
-the purpose of each of these appliances is the same -
- to keep the pharyngeal airway open
wide enough to prevent breathing efforts
from causing snoring, apnoea or arousal.

29. - the MADs vary in four major areas:
- freedom of mandibular movement,
- amount and rigidity of dental coverage,
- amount of mandibular advancement and
- amount of bite opening

30. a) freedom of mandibular movement
- an MAD that allows the mandible to move
several millimeters laterally or vertically is less likely
to produce TMDs, and is tolerated more readily by
bruxers.

31. - however ; there is no published
scientific evidence that an MAD that immobilizes
the mandible is more likely to cause TMD or that
it is less tolerable to bruxers in the short or long
term than one that allows the mandible some
freedom of movement.

32. b) amount and rigidity of dental coverage :
- the MAD uses the teeth as anchorage against this force,
pushing the mandibular arch forward and the maxillary arch
backward.
- such forces over time may change the angulation
of the teeth, especially the incisors.
- the more teeth held, the less force against each
tooth.
- all the teeth in both arches should be recruited into the
anchorage. This is particularly important in patients with missing
teeth or reduced alveolar bone support.

33. - any malocclusion resulting from
wearing a thermoplastic MAD is more likely to be the
result of the inclination of the teeth rather than of
changes in the TMJ.
-such resultant malocclusion usually is
reversible if treatment is discontinued.

34. c) amount of mandibular advancement :
- there is no direct correlation between the
amount of mandibular advancement and the efficacy
of an MAD.
- several adjustable MADs have become available
that can advance and retain the mandible upto 14 to 19
mm (exceeding 100 % of the protrusive range).
- unfortunately, results of these devices have been
approximately the same as those obtained with a MAD at
70 % protrusion.

35. d) amount of bite opening
- as the mouth opens, the anterior attachment
of the tongue swings not only down but also
backwards.
- this backward movement carries
the tongue toward the airway.
- for this reason, it has been concluded that MADs
should keep jaw opening to an “absolute minimum”.
- 2mm between the incisors.

36. - another advantage of
increasing the jaw opening is that it helps
part the lips allowing a passage for oral
breathing.
- this is important because
patients with SDB need assistance in breathing
when the nasal airway is inadequate.

37. “How do MADs keep the airway open?”
- as the mandible moves forward, so does the
tongue, and thus the airway enlarges.
while this explanation is accurate,
it is an oversimplification of
the mechanism.

38. - MADs 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.
- this muscle runs down and forward from the palate to
the tongue.

40. - this pull by the palatglossus muscle advances
the palate and increases its tension, making it less
likely to collapse or vibrate as in apnea or snoring.

41. - an MAD’s efficacy is based on more than a
simple cause – and - effect relationship between
advancement of the mandible and tongue.
- magnetic resonance images indicate that the
airways in patients who have SDB are constricted
more laterally than anteroposteriorly.
-moreover , the narrowest part of the pharyngeal
airway usually is not behind the tongue but behind
the soft palate; it is in the latter area that obstruction
is most likely to start.

42. ANTICIPATED RESULTS
- results in the treatment of SDB with an MAD
are not uniform.
- when using a properly constructed MAD, a
practitioners should anticipate :
- 90- 95 % success in treating primary
snoring and
- about 60 % success in treating
moderate to severe OSAHS

43. - success in snoring treatment may be
considered its elimination or reduction to a level
tolerable by a partner.
- success in OSAHS treatment may be
considered a 50% reduction in the number of sleep-
related obstructive breathing events per hour, as well
as a severity no greater than mild.

44. - most authors believe that MADs should be used
primarily in treating :
- snoring , and
- mild-to-moderate but
not severe OSAHS.
- because they are closer to mild cases, moderate
cases are more likely than severe cases to be
successfully treated,
- but the percentage of improvement cannot be
predicted by the severity of the SDB.

45. - results obtained with mandibular advancement device that held
mandible rigid at about 70 % protrusion and 5 mm bite opening.
- note that treatment response cannot be predicted from initial severity.

46. SUMMARY
- although MADs have earned an important
place in SDB therapy, the mechanisms by which they
achieve their results have not been completely
understood .
- since the efficacy of the various commercially
available MADs varies, dentists must subject the claims
of their promoters to scientific questioning and
reasoning.

47. - since MAD therapy may last a lifetime,
dentists should be concerned not only with MADs’
efficacy but with their safety,
--- as the major untoward
side effect appears to be a change in the occlusion.
- dentists should consider all available means to
monitor and minimize these changes.

48. - A.Johal et al
-British dental journal (2005)
-Department of Orthodontics,
(The Royal London School of Medicine and Dentistry)
The effect of a mandibular advancement splint in
subjects with sleep-related breathing disorders.

49. Introduction
The treatment objectives for patients with sleep-related breathing
disorders should be to alleviate snoring in simple snorers and to
resolve the clinical signs and symptoms in patients with
obstructive sleep apnoea with normalisation of the respiratory
disturbance index and oxyhaemoglobin saturation.
- for obstructive sleep apnoea, no currently available treatment
provides the ideal combination of high rate success and patient
compliance without complications.
- The majority of studies on the efficacy of mandibular advancement
splints are case reports or series although recent publications report
on prospective controlled trials investigating the differences
between MAS and other treatment modalities.

50. -the present study is a retrospective report on the effects of
mandibular advancement splints in two distinct subject groups,
-non-apnoeic snorers and
-subjects with obstructive sleep apnoea.

51. Objective
- to assess the effectiveness of a mandibular
advancement splint (MAS) in subjects with
sleep-related breathing disorders using both
objective and subjective outcome measures.

52. MATERIALS AND METHODS
- twenty subjects with obstructive sleep apnoea (OSA) and six with
non-apnoeic snoring, diagnosed by overnight polysomnography, were
fitted with a monobloc appliance between May1997 and March 2000.
The mandibular advancement splint (MAS)
-alginate impressions of the upper and lower dentition and an
interocclusal wax registration, recorded in a position of maximum
comfortable mandibular protrusion were obtained.
-A removable monobloc design was used . This consisted of a one-
piece hard acrylic splint incorporating full occlusal coverage and an
opening anteriorly to allow for mouth breathing. Additional retention was
obtained from Adam’s cribs on the upper and lower first premolars and
the upper first molars.
-Patients were instructed to wear the appliance at night-time only.

53. The mandibular advancement splint

54. - the respiratory disturbance index was calculated for each patient.
-A baseline respiratory disturbance index (RDI) score of below five was
used to distinguish non-apnoeic snorers from those with obstructive sleep
apnoea.
- All of the 26 subjects completed an Epworth Sleepiness Scale prior to
fitting the appliance and at the time of the repeat sleep study.

55. Outcome questionnaires
-a single operator attempted to contact all subjects by
telephone to complete an outcome questionnaire following
the repeat sleep study.
- the questionnaire was designed to assess
- snoring;
- sleepiness;
- complications of MAS therapy;
- the partner’s experience and
- comparison to nasal-CPAP, if relevant.

56. RESULTS
-all categories of obstructive sleep apnoea (mild, moderate, severe)
improved as a result of treatment, with an overall reduction in the
numbers of subjects with OSA, from 20 to 13.
-thus, the numbers of subjects with non-apnoeic snoring increased from six
to 13 as a result of intervention.

57. - no statistically significant change was observed in the
Epworth Sleepiness Scale scores in either subject group.
- However, subjects with obstructive sleep apnoea
demonstrated a reduction in median respiratory disturbance
index following mandibular advancement splint therapy.

58. DISCUSSION
- two of the most commonly used measures in assessing
treatment outcomes in sleep-related breathing disorders are the
Epworth sleepiness scale (ESS) and the respiratory disturbance
index (RDI).
- despite their subjective nature, questionnaire outcome
measures are also widely used.
- Polysomnography is regarded as the ‘gold standard’ for
diagnosing obstructive sleep apnoea (OSA) and is recommended for
the evaluation of treatment efficacy in moderate to severe OSA
subjects treated with mandibular advancement splints.
- However, the technique is expensive and not readily available,
requiring a special sleep laboratory and trained technical support.

59. CONCLUSION
- the monobloc appliance significantly improved the
respiratory disturbance index in the obstructive sleep apnoea
subjects.
-86 % of the subject’s partners reported better quality
of sleep following mandibular advancement splint therapy.
-some subjects had increased respiratory disturbance index scores
following splint therapy. This highlights the need for an objective
assessment in the follow-up of patients treated with mandibular
advancement splints.

60. -J. Lamont, D. R. Baldwin, K. D. Hay and A. G.Veale
-School of Dentistry, University of Otago, Dunedin, New Zealand
-European Journal of Orthodontics (1998)
Effect of two types of mandibular
advancement splints on snoring and
obstructive sleep apnoea

61. INTRODUCTION
- Treatment options for obstructive sleep apnoea (OSA) are limited.
- Mandibular advancement splints have been proposed as an alternative in
patients who have simple snoring or mild OSA but data on effectiveness
are conflicting .
-This may be a result of differing splint designs and research methodology.
-the aim of this study was to measure the effect of two types of splints on
daytime sleepiness,
snoring and
domiciliary sleep
in a sample of patients who might benefit from an alternative
treatment to a CPAP device, i.e. those with snoring alone or OSA with
intolerance of the CPAP.

62. Subjects and methods
-twenty-four subjects
(21 male, 3 female)
- who had been fitted with one or other of two different types of
splints were enrolled consecutively.
-All patients were snorers and seven were known to have OSA,
but were unable to tolerate the CPAP device.

63. • Mandibular advancement splints (MAS)
-both devices reposition the mandible forward and open the
vertical dimension of occlusion to a variable degree depending on
individual anatomy.
- Type A - devices produced maximal mandibular protrusion, with a 3–4
mm inter-incisal opening depending on the patient’s overbite.
- Type B - permitted up to 70 % maximal protrusion, and an opening of 6–9
mm, depending on the overbite.
- They both contained a breathing slot anteriorly. The devices were
made of transparent, soft acrylic resin which is physiologically harmless,
insoluble in water, odour-free, and inactive

64. Statistics:
-the Wilcoxon signed rank test, and
Mann– Whitney U-tests
were applied for paired and unpaired non-parametric data.
Results:
-twenty-three subjects aged 31–70 years completed
the study. One female was unable to tolerate the MAS and
was withdrawn from this study.

65. Apnoea/hypopnoea indices and ESS before and after
use of the mandibular advancement splints

66. DISCUSSION
- the efficacy of mandibular advancement splints in
snoring and OSA quoted in previous reports is variable .
-it is likely that this is related to differences in splint
design as well as patient selection.
-the present study showed that both splints
produced a reduction in daytime sleepiness and
number of apnoeas.
- type B was effective in reducing all measures of sleep
apnoea, including oxygen saturation and snoring.
-the differences in efficacy underlines the need for
research into the most effective design.

67. Conclusions
- the selection of patients in whom splints are the
most appropriate therapy has not yet been widely agreed.
- However, in view of the marked improvement in
symptoms for patients with snoring alone shown by the
present study and those of others, splints may be an
appropriate non-invasive first line therapy for such cases.
- as the splints may not produce adequate improvement in
AHI in some patients, it is important that objective
screening for OSA, possibly using oximetry or a more
comprehensive sleep study, should also be employed.

68. - In patients with OSA, it is clear that with splint therapy
both symptoms and the AHI may be reduced to
acceptable levels in some patients, but further work is
needed to evaluate long-term efficacy and patients
need to be studied with a device in place.
- The present study confirms the findings of others
that mandibular advancement splints may be a useful
alternative or adjunct to the use of the CPAP device in
selected patients with snoring and mild OSA.

69. Efficacy of two mandibular advancement
appliances in the management of snoring
and mild moderate sleep apnea:
A cross-over randomized study
- Luc Gauthier , Luc Laberge , Michel Beaudry , Mario Laforte
- Faculty of Dental Medicine, University of Montreal.
- Sleep Medicine 10 (2009)

70. Introduction
-mandibular advancement appliances (MAA) are indicated in the
treatment of snoring and mild - moderate obstructive sleep apnea
syndrome (OSAS) .
- although many studies have demonstrated that Continuous Positive
Airway Pressure (CPAP) is recognized as the ‘‘gold standard.”
-yet, MAA remain a valid alternative preferred by several
subjects .
-surprisingly few studies have compared the efficiency of two MAA using
the : - apnea/hypopnea index (AHI) or
- the respiratory disturbance index (RDI) or even
- patient or sleep partner satisfaction as outcomes .
Also , most of these studies include a large range of severity, from
very mild to highly severe OSAS subjects.

71. - the present study aimed to assess the efficacy and
patient/sleep partner satisfaction with two MAA in subjects
with mild-moderate RDI .
(apnea + hypopnea + respiratory effort-related
arousal per hour of sleep, RERA).
- the null hypothesis is that the Klearway is equivalent to the
Silencer for the management of OSAS patients.
- the alternative hypothesis is that one appliance is superior.

72. Material and methods
- in a prospective, single blind cross-over and randomized
study comparing two MAA ;16 subjects were enrolled from
the sleep disorders clinic of a hospital for a six-month period
(three months for each MAA) and a follow- up interview.
- inclusion criteria included:
- a history of snoring, the presence of natural
teeth on both dental arches.
- exclusion criteria were:
- previous treatment for OSAS, caries, periodontal
disease, jaw pain or mandibular movement
limitations

73. - appliances:
- the two commercially produced MAA used in the
study were the Klearway and the Silencer .
-both MAA offer an interincisal space of 9–12 mm.

74. - subjects wore each MAA for two consecutive 12-
week periods .
-the bite was taken on average at
- 6.5 mm for the Silencer and at
- 8.5 mm for the Klearway,
and the maximal advancement was on average
- 10.5 mm for the Silencer and
- 12.5 mm for the Klearway.
-the advancements were made by patients twice a
week and verified by a dentist every four weeks.

75. Success criteria and statistical analysis
- Sleep apnea treatment success criteria used was the 50%
RDI reduction.
- ANOVAs for repeated measures were used to evaluate
treatment effects. Paired comparisons were then used to
assess differences between Klearway and Silencer.
- p value 60.05 was used to assess the significance level. Data
are presented as mean values ± standard error.

76. Results

78. Discussion
- the present study confirms that both the Klearway and Silencer are
effective but similar in their capacity to reduce RDI in a population of
subjects with mild-moderate OSAS, previously untreated with CPAP.
- Moreover, subjects’ sleep quality and quality of life were
significantly improved.
-The Silencer is made with an advancement mechanism that provides
more oral space for the tongue compared to the Klearway, so it remains
to be demonstrated whether the differences between efficacy of the
appliances is related to tongue space.
-The clinical relevance of this effect needs to be reproduced.

79. Conclusion
- The present results confirm that both types of MAA are
indicated in the management of mild-moderate OSAS.
- Since both MAA decreased RDI and subjective daytime sleepiness in a
similar manner, the choice of an oral appliance needs to be weighted
giving due consideration to :
- the benefit of RDI reduction (in favor of the Silencer)
- over benefit of subject compliance (in favor of the Klearway).
-The long term benefit of a better RDI reduction vs. a better patient
compliance needs to be assessed in prospective studies.

80. Thank you