Keywords
obstructive sleep apnea syndrome - oral appliance therapy - upper airway
Introduction
Obstructive sleep apnea (OSA) is a chronic, inflammatory, and progressive disease.[1]
[2] Its prevalence in the general population is between 9 and 38%, and varies according
to age and gender.[3] The diagnosis[4] requires either signs/symptoms (e.g., associated sleepiness, fatigue, insomnia,
snoring, subjective nocturnal respiratory disturbance, or observed apnea) or associated
medical or psychiatric disorder (i.e., hypertension, coronary artery disease, atrial
fibrillation, congestive heart failure, stroke, diabetes, cognitive dysfunction, or
mood disorder) coupled with five or more predominantly obstructive respiratory events
(obstructive and mixed apneas, hypopneas, or respiratory effort-related arousals,
as defined by the American Academy of Sleep Medicine scoring manual) per hour of sleep
during polysomnography (PSG). Alternatively, a frequency of obstructive respiratory
events 15/hour satisfies the criteria, even in the absence of associated symptoms
or disorders.
Clinical symptoms vary depending on the type, frequency, and intensity of the respiratory
abnormality.[5]
[6] Normal rates of apnea should also be treated when associated with snoring, although
some controversial issues persist regarding the therapeutic criteria for snoring itself.[7]
The most recommended devices for usage by American Academy of Sleep Medicine and the
American Academy of Dental Sleep Medicine[8] are the oral appliance with mandibular advancement (OAm) for the treatment of primary snoring, mild and moderate obstructive sleep apnea
(OSA), and the continuous positive airway pressure (CPAP) to moderate to severe OSA.
In addition, OAm can be considered after CPAP has been failed in nonadherent patients treatment or
in patient preference in therapy choosing.[9]
[10]
The new generation of OAm devices presents considerable advances in design, construction techniques, and individualization
capacity. Considering the assumptions of design, construction, and individualization,
OAm can further impact the effectiveness of oral appliance therapy (OAT).[8]
One of the problems related to respiratory disorders is the maxillomandibular relationship,
both vertically, sagittal and transversal,[11] significant differences existed in the cranio-facial morphology of patients with
OSA and the healthy population. In addition to this relationship, which is so important,
most malocclusions are treated based on a conventional analog or digital model,[12] which does not faithfully reproduce their interrelationships with cranial structures.
These therapeutic proceed can bring important repercussions in the lives of these
patients for not considering the intimate interrelationship of the dental arches with
the craniofacial structures.[13] Likewise, most OAm are structured, using models dissociated from their relationship with craniometric
structures and, consequently, with the muscles involved in mandibular protrusion movements.
The functional anatomic factors leading to oropharynx and hypopharynx airway collapse
in OSA,[14]
[15] are in part related to the retracted position of the mandible and tongue with sagging
soft palate. The principal mechanism of action of OAm is by promoting the advancement of the mandible or tongue[14]
[16] because simple active anterior movement of the tongue or mandible can increase cross
sectional airway size in subjects with and without OSA[17]
[18] and, increasing the pharynx muscles tone and therefore the airway patency. Ideally,
these situations could be achieved in the OAm mode of action simultaneously.[14]
[19]
[20]
[21]
[22]
One of the first functional mandibular activator devices was developed in Europe in
the early 20th century which became a universal device widely used, thanks to Viggo
Andresen. The removable activator devices were built to redirect the pressure of facial
muscles and masticatory onto teeth and support structures to improve dental arrangement
and occlusal relationships. This author used the Camper plane for diagnosis and follow-up.
The Camper plane is a plane established by superior border of the tragus left and
right to the lowest point of ala border.[23]
In OAT, the neuromuscular system will be activated through OAm maintaining upper airway patency, toning the oropharynx muscles, thus preventing
collapse between the tissues of the oropharynx and tongue base,[24] and improving tongue posture.[25] The OAm cannot exceed anatomical physiological limits. Therefore, the choice of OAm for the treatment of OSA should be considered by Dental Sleep Medicine.[21]
[24]
[26]
[27]
[28]
In searching for functional balance, the DIORS OAm design[29] considered these two situations because it was designed based on functional anatomy
of buco-dental biology. The OAm disocclusion is guided to Camper plane based on fixed individual skull structures.
At same time, it stimulates the tongue for advancement, promoting lip sealing which
further improve the airway patency.
In Dental Sleep Medicine clinical practice,[8] there are diagnostic and complementary exams with objective and subjective parameters
need for records as polysomnography exam for diagnosing OSA, intra- and extraoral
photographic examination to assess facial patterns, oral conditions, and follow-up
cephalometric analyze of the airway space, which makes it possible to check the mandible
and tongue position in relation bone structures[14]
[30]
[31]
[32]
[33] and models of the dental arches for recording and making the OAm. In addition to these objective parameters, the Epworth sleepiness scale is a subjective
parameter, of proven validity, used for the evaluation and monitoring of the patient
after treatment.[8]
Thus, the aim of this pilot study is to compare the impact of OAm that use Camper plane for reference to disocclusion, on the upper airways in snore
and OSA patients, in the pre- and post-treatment in a private dental office through
cephalometric analysis, and the effectiveness of this different OAm through polysomnographic parameters. Also, verify if there is a correlation with
these variables associated with clinical practice.
Materials and Methods
Study Design
A retrospective longitudinal study was developed from dental sleep medical records
of OSA patients treated with DIORS OAm, manufactured by the first author in her dental office, Jundiaí, SP, Brazil. The
results were measuring and comparing by objective (polysomnography and cephalometric
data) and subjective (Epworth sleepiness scale and adherence, symptoms, satisfaction,
and safety questionnaires) data pre- and post-treatment. The data analysis was conducted
by applying quantitative techniques and multiple comparisons ([Fig. 1]).
Fig. 1 Diagram of study development.
The study was approved by the School of Odontology of Piracicaba UNICAMP Ethics Committee,
SP, Brazil (CAAE: 20672219.3.0000.5418 P.N. /4.034.661). This study counted patients
attending in private dental office with authorized and formalize participation with
the informed consent.
Sample
In view of the nature of the variables to be analyzed, a sample size calculation was
made based on the application of the Student t-test for paired data where the mean referring of null hypothesis was 0; the significant
average, of two different units; the standard deviation of 4; and the desired power,
80%, resulting in a total sample of 34 patients.
The inclusion criteria were both genders adult patients with snoring and mild, moderate
and severe OSA prescribed by Sleep Physician treated with DIORS OAm in the first author dental office from 2011 to 2019 period, with completed medical
records and protocol of 2 to 3 months of OAm adjustment. The records needed to have Epworth sleepiness scale, polysomnography
and cephalometry pre- and post-treatment. The exclusion criteria were incomplete dental
sleep medical records and patients that not permitted used the data for research.
The success criteria established in this study regarding elimination or decreasing
of AHI symptoms[17]
[29] were (1) successful (AHI < 5/hour); (2), partly successful (at least 50% reduction
in AHI, but AHI > 5/hour; and (3) failure (persisting clinical symptoms, and/or less
than 50% reduction in baseline AHI).
In [Table 1], the characteristics of 33 adults with anthropometrics and polysomnographic and
cephalometric data are showed. The anthropometric data consist in 25 men and 8 women
pre- and post-treatment with mean (standard deviation) of 50.53 (10.29) years old
and body mass index (BMI) of 27.70 (3.27). The angle occlusal classification of these
sample is 86.96% of Class I and 13.04% of Class II. The AHI variation was 11.92 (12.80).
Based on OSA severity, the sample consisted in simple snoring or normal apnea (AHI < 5)
in 2.17%, mild (5 ≤ AHI < 15) in 26.09%, moderate (15 ≤ AHI < 30) in 13.04%, and severe
(AHI ≥ 30) in 8.7%.
Table 1
Mean, standard deviation, and confidence limits of the mean (95%) that characterize
sample data (n = 33)
|
Characteristics
|
Mean
|
Standard deviation
|
95% confidence limit
|
Minimum
|
Maximum
|
|
Upper
|
Lower
|
|
Anthropometric data
|
|
Cervical waist
|
40.76
|
4.59
|
42.44
|
39.07
|
33.50
|
55.00
|
|
Abdominal waist
|
98.98
|
10.21
|
102.73
|
95.24
|
74.00
|
117.00
|
|
Age
|
50.53
|
10.29
|
54.18
|
46.88
|
29.54
|
70.92
|
|
Weight (kg)
|
83.65
|
14.54
|
87.31
|
79.99
|
58.00
|
115.00
|
|
BMI (kg/m2)
|
27.70
|
3.27
|
28.53
|
26.88
|
20.05
|
37.10
|
|
Polysomnographic data
|
|
Epworth sleepiness scale
|
8.22
|
4.53
|
9.36
|
7.08
|
1.00
|
20.00
|
|
Arousal index
|
9.05
|
8.90
|
11.29
|
6.81
|
0.40
|
53.13
|
|
SaO2 minimum (%)
|
85.57
|
5.65
|
86.99
|
84.15
|
64.00
|
93.00
|
|
Sleep efficiency
|
76.83
|
12.38
|
79.95
|
73.72
|
45.60
|
96.00
|
|
Apnea
|
4.89
|
8.56
|
7.05
|
2.74
|
0.00
|
43.40
|
|
Hypopnea
|
7.02
|
6.78
|
8.73
|
5.32
|
0.00
|
33.72
|
|
AHI
|
11.92
|
12.80
|
15.14
|
8.70
|
0.20
|
64.18
|
|
Minimum heartbeat
|
54.71
|
7.60
|
56.71
|
52.71
|
44.00
|
78.00
|
|
Maximum heartbeat
|
78.06
|
13.20
|
81.53
|
74.59
|
57.00
|
137.00
|
|
Legs movements
|
3.29
|
7.83
|
5.30
|
1.29
|
0.00
|
36.20
|
|
Cephalometric data
|
|
Upper pharyngeal space
|
17.74
|
4.14
|
18.76
|
16.72
|
9.83
|
27.07
|
|
Soft palate length
|
41.90
|
5.88
|
43.34
|
40.45
|
28.23
|
58.57
|
|
Posterior air space
|
13.85
|
4.20
|
14.88
|
12.82
|
6.05
|
25.61
|
|
Hyoid distance mandibular plane
|
22.89
|
7.54
|
24.75
|
21.04
|
10.31
|
41.39
|
|
Tongue length
|
78.84
|
9.27
|
81.12
|
76.56
|
57.46
|
97.30
|
|
Tongue height
|
29.30
|
5.46
|
30.64
|
27.95
|
14.47
|
44.75
|
|
Lower air space
|
12.79
|
4.65
|
13.94
|
11.65
|
5.14
|
24.69
|
|
Hyoid distance third cervical vertebrae
|
42.81
|
5.42
|
44.15
|
41.48
|
32.40
|
53.32
|
Abbreviations: AHI, apnea-hypopnea index; BMI, body mass index; SaO2, oxygen saturation.
Polysomnography
Each subject underwent polysomnography all-night recordings in the sleep laboratory
in two phases pre- and post-treatment. The polysomnographic study used was Brain Wave
II Polysomnography (Neurovirtual, Barueri – SP/Brazil) performed by physicians specially
trained in sleep medicine. The AHI was defined as the number of episodes of apnea
plus episodes of hypopnea per hour of sleep. OSA was defined as AHI ≥5.
Cephalometry
Cephalometric parameters were taken for the location of obstruction sites and to clarifying
specific parameters to the upper airway with the software Radio Memory Studio 3.0
Release 7.80 (Radio Memory LTDA, Belo Horizonte – MG/Brazil). Several analysis has
been widely described in literature.[14]
[30]
[31]
[32]
[33] The cephalometric analysis of airway space used and covered in two phases: without
and with OAm pre- and post-treatment. The majority teleradiographs and cephalometric analysis
(91.3%) was performed by a single evaluator of Speed X Dental Documentation Center
with Instrumentarium OC 200 Xray (KaVo company, Finland). Patients were instructed
to swallow and to close their mouths with maximal intercuspation and the lips in a
relaxed position when they were without and with OAm.
Anatomically, the pharyngeal airway is divided in nasopharyngeal, oropharyngeal, and
hypopharyngeal.[32] The cephalometric variables analysis of airway space used were mapped in [Fig. 2A] (pretreatment) and 2B (pre-treatment) showing the mode of action of OAm used in the study to identify tongue, soft palate, and pharyngeal airway.
Fig. 2 The mode of action of oral appliance with mandibular advancement used are mapped
in (A) (pre-treatment) and (B) (post-treatment) in of airway space to identify tongue, soft palate, and pharyngeal
airway. Lines and plans used in cephalometric variables analysis: soft palate length;
posterior air space; hyoid distance third cervical vertebrae; hyoid distance mandibular
plane; tongue length; tongue height; and lower air space.
Oral Appliance Therapy
Impressions of the dental arches and face bow to construct the gnathostatic study
model based on Camper plane were made, and the constructive bite was determined by
using George Gauge® bite fork.
The initial protocol of OAm construction were with 65 to 75% maximum protrusion and a vertical opening of 3 to
4 mm between incisor edges. The efficacy of OAm was determined by using additional PSG with OAm in situ after a minimum of 3 months.
Questionnaires
Subjective daytime sleepiness was evaluated by applying the Epworth sleepiness scale
pre- and post-treatment, and a questionnaire to assess snoring, adherence, satisfaction,
and safety of OAm usage to partners and to the patient follow-up. The adapted questionnaire[29] consisted in following questions: Are you using OAm? If yes, mark on a scale of 1 to 3 (where: 1 = little, 2 = medium and 3 = a lot);
Is your partner snoring with OAm? If yes, mark on a scale of 1 to 3 (where: 1 = little, 2 = medium and 3 = a lot);
and Are you totally satisfied with OAm? Has OAm already broken?
Success Criteria
We evaluated the successful criteria of therapies with arousal index in addition to
respiratory parameters, as AHI and SaO2, and daytime sleepiness. Despite the lack of consensus regarding the definition of
a successful criteria,[17] three successful criteria were adopted as a resolution of symptoms plus reduction
of AHI: (1) success in AHI to <5/hour; (2) partial success at least 50% reduction
in AHI, but AHI >5/hour; and (3) failure ongoing clinical symptoms and/or less than
a 50% reduction in baseline AHI.
Synthesis of Statistical Analysis
Descriptive analysis based in contingency tables and correlated Chi-square tests and
basic statistics was used to characterize the sample. Generalized linear mixed model
for repeated measure and post hoc Tukey–Kramer test compares the variables pre- and
post-treatment. Residual normality was accessed by the Shapiro–Wilk Test and Pearson
correlation coefficients was used to test and quantify the association between polysomnographic
and cephalometric data. All analysis was calculated by using the SAS System (SAS Institute
Inc. The SAS System, release 9.4. SAS Institute Inc., Cary, North Carolina, United
States, 2012) and in all statistical tests the level of significance was set in 5%.
Results
The polysomnographic data comparison pre- and post- treatment with OAm ([Table 2]) of sleep efficiency, AHI, AI, SaO2, and maximum heartbeats are the greatest significance (p < 0.0001). In the same way, the cephalometric data comparison regarding to the hyoid
distance mandibular plane (H-MP) and upper pharyngeal space. Accompanied by other
variables with significant results as the tongue length (TGL; p = 0.01), tongue height (TGH; p = 0.003), posterior air space (PAS; p = 0.002), and lower air space (LAS; p = 0.01).
Table 2
Cephalometric comparison of the mean (standard deviation) of the pre- and post-treatment
variables with the mandibular oral appliance (n = 33)
|
Characteristics
|
Phase
|
p-Value
|
|
Pre-treatment
|
Post-treatment
|
|
Anthropometric data
|
|
BMI (kg/m2)
|
27.63 (3.24)
|
27.77 (3.24)
|
0.4172
|
|
Polysomnographic data
|
|
Epworth sleepiness scale
|
9.70 (4.97)
|
6.88 (3.68)
|
0.0004
|
|
Arousal index
|
12.90 (10.91)
|
5.55 (4.38)
|
<0.0001
|
|
SaO2 minute (%)
|
82.87 (6.24)
|
88.03 (3.67)
|
<0.0001
|
|
Sleep efficiency
|
76.09 (11.92)
|
77.51 (12.93)
|
<0.0001
|
|
Apnea
|
8.57 (10.94)
|
1.56 (3.09)
|
0.0058
|
|
Hypopnea
|
9.28 (7.76)
|
4.97 (5.06)
|
0.0318
|
|
AHI
|
17.86 (15.45)
|
6.52 (6.19)
|
<0.0001
|
|
Minimum heartbeat
|
54.63 (7.20)
|
54.77 (8.06)
|
0.9655
|
|
Maximum heartbeat
|
81.42 (9.99)
|
75.13 (15.02)
|
0.0140
|
|
Legs movements
|
2.20 (5.17)
|
4.29 (9.61)
|
0.7172
|
|
Cephalometric data
|
|
Upper pharyngeal space
|
15.90 (3.69)
|
19.58 (3.77)
|
<0.0001
|
|
Soft palate length
|
40.76 (5.83)
|
43.03 (5.80)
|
0.0206
|
|
Posterior air space
|
12.71 (4.21)
|
14.99 (3.94)
|
0.0024
|
|
Hyoid distance mandibular plane
|
26.51 (7.44)
|
19.28 (5.77)
|
<0.0001
|
|
Tongue length
|
77.75 (9.23)
|
79.93 (9.32)
|
0.0153
|
|
Tongue height
|
27.84 (5.20)
|
30.75 (5.41)
|
0.0039
|
|
Lower air space
|
11.99 (4.63)
|
13.60 (4.60)
|
0.0192
|
|
Hyoid distance third cervical vertebrae
|
42.41 (5.60)
|
43.22 (5.29)
|
0.3052
|
|
Oral appliance therapy
|
|
OAm advancement (%)
|
61.12 (15.44)
|
100.70 (31.11)
|
<.0001
|
Abbreviations: BMI, body mass index; OAm, oral appliance with mandibular advancement; SaO2 minimum, minimum oxygen saturation.
The mean OAm adjustment pre- and post-treatment was conducted for 61.12% (15.44) to 100.70% (31.11)
showing an important advancement (p < 0.0001) associated with the results.
Based on severity of AHI, the pre- and post-treatment with OAm are represent in [Table 3] and [Fig. 3]. The frequencies and percentages in line show a significant result in different
levels of AHI (p = 0.0001), with 17 total success (51.51%), 9 partial success (27.27%), and 7 unsuccess
(21.21%). In four patients with severe AHI, three reduce the AHI to mild and one to
normal.
Fig. 3 Pre- and post-treatment of obstructive sleep apnea patients without and with oral
appliance with mandibular advancement.
Table 3
Chi-square likelihood ratio test with frequency and percentage in line of the apnea-hypopnea
index classification and treatment phase (n = 33)
|
AHI classification
|
Phase
|
|
Pre-treatment
|
Post-treatment
|
|
Normal
|
4 (6.06)
|
17 (25.76)
|
|
Mild
|
16 (24.24)
|
14 (21.21)
|
|
Moderate
|
9 (13.64)
|
2 (3.03)
|
|
Severe
|
4 (6.06)
|
|
Abbreviations: AHI, apnea-hypopnea index.
Note: p-Value = 0.0001.
The improvement in respiratory parameters was confirmed not only by comparing the
polysomnographic data (p < 0.0001) but also through direct associations ([Table 4]) between AHI and both AI and maximum hazard ratio (HR), with correlation indices
for AHI and AI (r = 0.87601, p = 0.0001) and for AHI and the maximum HR (r = 0.51025, p = 0.0001), respectively; and an indirect association between AHI and SaO2 (r = − 0.54760; p = 0.0008).
Table 4
Pearson's correlation index (p-value) for quantifying the association between polysomnographic variables
|
AHI
|
SaO2 (min) %
|
Minimum heartbeats
|
|
SaO2 (min)%
|
−0.54760
|
(0.0001)
|
|
|
|
Arousal index
|
0.87601
|
(0.0001)
|
−0.41245
|
(0.0008)
|
|
|
Maximum heartbeats
|
|
|
0.51025
|
(0.0001)
|
Abbreviations: AHI, apnea and hypopnea index; SaO2 (min), minimum oxygen saturation.
The pharyngeal space was expanded by considering the comparison and correlation of
the cephalometric measurements ([Tables 2] and [4]). The hyoid bone presented movement in the upward and forward [Table 5], confirmed by the H-MP (p < 0.0001). The greater the PAS score, the greater the LAS (r = 0.88151; p = 0.0001) achieved through OAT. Moreover, the correlation of the mandible-tongue
relationship with the hyoid bone showed that the position of the H-MP directly correlated
with the H-C3 (p = 0.0034) and with the TGL (p = 0.0268), pre- and post-treatment. In addition, when the mandible and tongue were
protracted, there was a functional relationship between the hyoid bone and airway.
Table 5
Persson's correlation index (p-value) to quantify the association between cephalometric variables
|
Variables
|
TGH
|
TGL
|
LAS
|
H-C3
|
|
PAS
|
0.49702
|
0.0001[b]
|
0.26976
|
0.0285[a]
|
0.88151
|
0.0001[b]
|
0.52311
|
0.0001[b]
|
|
PNS-P
|
0.47445
|
0.0001[b]
|
0.63226
|
0.0001[b]
|
NS
|
0.38235
|
0.0015[b]
|
|
TGH
|
|
0.65813
|
0.0001[b]
|
0.30195
|
0.0137[b]
|
0.43336
|
0.0003[b]
|
|
H-MP
|
NS
|
0.27259
|
0.0268[a]
|
NS
|
0.35549
|
0.0034[b]
|
|
H-C3
|
0.43336
|
0.0003[b]
|
0.55623
|
0.0001[b]
|
0.47060
|
0.0001[b]
|
.
|
Abbreviations: H-C3, hyoid distance third cervical vertebra; H-MP, hyoid distance
mandibular plane; LAS, lower air space; NS, not significant; PAS, posterior air space;
PNS-P, soft palate length; TGH, tongue height; TGL, tongue length.
a
p < 0.05.
b
p < 0.01.
When cephalometric with polysomnographic variables were correlated, the H-MP is significantly
with AHI (r = 0.44025; p = 0.0003) and with AI (r = 0.37683; p = 0.0023).
In Epworth sleepiness scale questionnaire used for evaluating subjective parameters
([Table 2]), we observe a significant response in daytime sleepiness (p = 0.0004). Furthermore, we used a questionnaire to evaluate the adherence, usage,
and security of OAm ([Table 6]) showing a significant response (p = 0.001) for all questions except those related to snoring. Although 12 patients
continued to present snoring, it was of low intensity (p = 0.0017).
Table 6
Frequency, percentage on the line, and Chi-square test (p-value) of the answers obtained in the questionnaire applied to assess adherence,
satisfaction and safety of oral appliance with mandibular advancement
|
Questions
|
Frequency
|
%
|
p-Value
|
|
Are you using OAm?
|
|
No
|
2
|
6.06
|
<0.0001
|
|
Yes
|
31
|
93.94
|
|
Score use of 1 to 3
|
|
1
|
1
|
3.23
|
<0.0001
|
|
2
|
3
|
9.68
|
|
3
|
27
|
87.1
|
|
Are you using it every night?
|
|
No
|
2
|
6.45
|
<0.0001
|
|
Yes
|
29
|
93.55
|
|
Do you use OAm every night in week?
|
|
No
|
3
|
9.67
|
<0.0001
|
|
Yes
|
28
|
90.32
|
|
Is your partner snoring with OAm?
|
|
No
|
19
|
61.29
|
0.2087
|
|
Yes
|
12
|
38.71
|
|
On what snoring score?
|
|
0
|
18
|
60
|
0.0017
|
|
1
|
10
|
33.33
|
|
3
|
2
|
6.67
|
|
Are you totally satisfied with OAm?
|
|
No
|
2
|
6.67
|
<0.0001
|
|
Yes
|
28
|
93.33
|
|
Has OAm ever broken?
|
|
No
|
26
|
83.87
|
0.0002
|
|
Yes
|
5
|
16.13
|
Abbreviation: OAm, oral appliance with mandibular advancement.
Note: Score = 0 = none, 1 = little, 2 = medium and 3 = much/many.
Regarding adverse effects and symptoms from using the OAm, 12 patients experienced mild and transitory adverse effects at the start of the
treatment, which were resolved through massage in two patients, asymmetric adjustment
in OAm to adjust the mandibular posture in eight cases, and specific occlusal adjustments
of imbalanced occlusion in four cases.
Discussion
Here we provide the effectiveness of DIORS OAm on the outcome of OAT by expertise of the professional and the compliance of the
patient. The positive effects of OAm that use Camper plane for disocclusion reference were demonstrated through comparison
and correlation of objective data from polysomnography and cephalometry. In a sample
of 33 patients of both genders, with primary snoring to severe OSA, we adopted the
most impartial success criteria for apnea (AHI <5ev/hour)[17] resulting in 51.51% total successes to 27.27% partial success cases. Even so, the
results are quite significant (p < 0.0001) for AHI, AI, SaO2 minimum, and for the maximum heartbeats ([Table 2]).
The OAm design, construction, and individualization influence the efficacy of OAT.[3] We agree that one of the problems related to respiratory disorders is the skull
structures relationship.[11]
[13] In addition, the dental arches must be considered with to craniofacial structures.
Unfortunately, most OAm are structured, using models dissociated from their relationship with craniometric
structures and, consequently, without respecting the muscles involved in mandibular
protrusion movements. Here, we show an OAm that considers the morpho functional anatomy when seeking equilibrium for the stomatognathic
system.
In polysomnographic variables, we observed the higher AHI the greater the arousal
index and the greater the maximum heartbeats. In contrast, the higher the AHI, the
lower the SaO2. In a study of various types of OAm
[34] showing variable of success in the treatment of mild-to-moderate OSA to distinguish
treatment responder from nonresponder patients, the authors observed that definitive
device was effective in improving respiratory parameters as AHI as we observed in
our data, but in the SaO2, they do not observed the same result that we had observed in our findings (p < 0.0001). When correlating heartbeats, both variables increase ([Table 4]). Based on these correlations together with comparison results, the effectiveness
of OAT is confirmed in the upper airway permeability improvement. In addition, contributing
to the AHI and AI, it also contributed to heartbeats improvement.[8] All patients with severe OSA in this sample were treated, with three patients achieving
a reduction of more than 50% in AHI and one patient reaching a normal level. In this
sample, only two patients with moderate OSA did not respond to OAT. These patients
presented clinically angle occlusal classification of Class I, large volume of tongue,
flaccid soft palate, and cervical waist more than 40 cm. In these cases of nonresponders
patients to OAT, an alternative combined treatment with positive airway pressure[10]
[34] or myofunctional therapy[35] and BMI control[36] can be prescribed to improve the AHI responses and patency of air space.
Based in cephalometric studies,[14]
[30]
[31]
[32]
[33] here we also demonstrate the impact of OAm in upper airways with the uniquely designed OAm that advances the jaw and tongue simultaneously. Our findings reinforce former studies
that showed that craniofacial morphology, which included bone and soft tissues, predisposed
to OSAS, reducing the permeability of the upper airways.
Anatomically, the tongue maintains several relationships with the hyoid bone[25] and, therefore, with the hyoid muscle. Several muscles of the tongue are inserted
directly into the hyoid bone. Thus, the displacement of the tongue forward acts on
the hyoid bone and vice versa, influencing the upward (cranial) displacement of the
hyoid bone. The protrusion of the tongue or mandible, increasing the size of the airway
cross-section in individuals with and without OSA, was already showed with the OAT.[14]
[17]
[37] Furthermore, the significant increase in the upper airway permeability is probable
related to OAm design.[18] In our findings, we demonstrate that the OAm used in this study that use Camper plane as reference to disocclusion permits the
jaw and the tongue simultaneous advancement and significantly increase the upper airway
in OSA patients ([Fig. 2]), confirming the effectiveness of this OAm ([Fig. 3]). This affirmative is correlating to cephalometric and polysomnographic variables,
demonstrating that the position of the hyoid bone is partly a factor that can interfere
with airway permeability and sleep quality contributing to the significant reduction
of these indexes (p < 0.0001).
In the subjective parameters, the Epworth sleepiness scale presents a significant
result (p < 0.0005). The questionnaire applied associated with adherence, satisfaction, symptoms,
and safety of using OAm ([Table 6]), we found significant results in terms of satisfaction and adherence (p = 0.0001), although there is still snoring presence, the results show an extremely
low score, without disturbing the bed partner. Finally, safety of use shows that this
OAm is safe to use (p = 0.0006).
The limitation of this study was the two-dimensional image used without provide volumetric
measurements as OSA diagnostic tool, but this limitation was reduced with the follow-up
polysomnography parameters. In addition, this sample was obtained in a private dental
office that uses on protocol the cephalometry as a complementary diagnose tool, accessible
to assist in the general assessment of soft tissues and bone configuration in the
OAT.[14]
[30]
[31]
[32]
[33] Even though, the statistical data obtained are encouraging, they need to be reinforced
through further investigation about OAm design in larger studies to evaluate the clinical importance regard to the tongue,
hyoid, mandibular posture, and the soft palate length in apneic patients pre- and
post- treatment.
Conclusion
The OAT is an important determinant in the upper airway permeability in OSA treatment,
reducing snoring and daytime sleepiness. In this pilot study, DIORS OAm as an uniquely designed device using Camper plane as a reference for disocclusion
was effective in the control of OSA. Future studies should test and compare other
OAm with DIORS OAm to confirm such important findings.
