Ricardo C. Barbosa*, Flavio Aloe†, Stella M. Tavares†§ , Ademir B. Silva‡

*Dentistry School , Universidade de São Paulo - São Paulo-SP-Brazil;

†Sleep-Wake Disorders Center, Universidade de São Paulo General Hospital, São Paulo-SP-Brazil;

‡Department of Neurology, Universidade Federal de São Paulo, São Paulo-SP-Brazil;

§ Sleep-Wake Disorders Center - Hospital Israelita Albert Einstein, São Paulo-SP-Brazil.

Introduction:
Sleep-disordered breathing ranges from partial airway collapse and increased upper-airway resistance manifested as loud snoring to recurrent airway total or partial collapse with respectively apneas and hypopneas. Obstructive sleep apnea syndrome (OSAS) is a potentially life-threatening disorder and it causes daytime sleepiness with motor vehicle accidents and cardiovascular morbity and mortality. Reports that snoring is associated with stroke, myocardial infarction, and hypertension suggest that even mild degree of sleep-disordered breathing has negative effects. Therefore, even mild degree OSA demands an effective treatment. Although nasal CPAP is therapeutically effective, its compliance rate is poor even for more severe OSAS cases. Hence, removable intraoral appliances have become a treatment alternative for OSAS. The objective of this study is to assess treatment effectiveness of the MLRD2 in 16 OSAS subjects.

 

Methods:
16 patients (13M/3F), age = 37 to 68, (avg=52.5), BMI = avg 26.76 ± 4.27 with a PSG-confirmed OSAS diagnosis were included (RDI = avg 53.57 ± 21.82). Pre-treatment and pos-treatment indexes obtained at approximately 4 months later for both groups included: RDI, Epworth Sleepiness Scale (ESS) subjective daytime sleepiness scores2, min.SatO2%. Student's t-test was employed to pre and post-treatment conditions. Cure criteria were RDI < 10 /hour and min.SatO2%> 90%.

Results:
The results are presented in Table I 

PATIENT	BMI	RDI pre	RDI post	Sat O2 min pre	Sat O2 min post	ESS pre	Ess post
1	27,02	77,14	9,22	69%	89%	10	3
2	20,46	76,80	43,00	57%	79%	16	5
3	27,12	58,00	7,53	79%	80%	7	6
4	27,19	41,26	5,10	93%	94%	14	4
5	25,82	43,70	3,60	88%	88%	20	18
6	36,30	113,40	51,93	54%	75%	23	10
7	29,41	28,87	22,11	80%	92%	9	5
8	27,46	67,20	22,03	59%	78%	15	9
9	20,61	40,80	3,80	73%	84%	15	7
10	23,67	46,50	13,40	85%	90%	15	6
11	23,16	53,25	7,21	71%	79%	18	7
12	35,82	14,77	2,50	80%	90%	5	1
13	24,41	50,00	10,50	73%	92%	10	2
14	24,91	55,00	0,00	90%	92%	12	4
15	27,08	43,80	11,70	70%	77%	12	5
16	27,77	46,70	0,00	90%	90%	7	4
AVG	26.76	53.57	13.35	75.69%	85.56%	13.00	6.00
S.D.	4,27	21.82	14,46	11.75%	6.29%	4.80	3.84

Results:
RDI was reduced to less than 10 events/hour in nine subjects (56.25%) (subjects 1,3,4,5,9, 11,12,14,16) and 6 of these subjects (37.50%) displayed pre-treatment RDI>40 events/hour. Post-treatment ESS score< 10 points was recorded in 15 subjects (93.75%). Post-treatment min.SatO2%> 90% was recorded in subjects 4,7,10,12,13,14 and 16 (43.75%), and subjects 4,12,14 and 16 (25%) met the criteria for cure. 

Discussion:
Pre- and pos-treatment RDI, ESS, min Sat O2.% were statistically different confirming the MLRD efficiency in this patient population. However, the pattern of post-treatment improvement degree ranked ESS score<10 points, RDI<10, minSatO2%> 90% and cure. MLRD-induced Improvement in ESS-measured subjective daytime sleepiness has been reported before 2. Yet, the degree of oxygen desaturation relates to abnormal respiratory event duration. This is suggestive the ARML is more efficient in reducing the number of arousals, and in reducing the number than the duration of abnormal respiratory events.

Conclusion:
ESS and RDI intraoral appliance-induced clinical improvement is more robust than min.SatO2..

 

Bibliography:

  1 - Young T, Paita M, Dempsey J, Skatrud J, Webber S, Badr S. The occurance of sleep disordered breathing among middle aged adults. N Engl J Med 1993, 328:1230-1235.

  2 - Barbosa RC, Aloe F, Tavares SM, Silva AB. Evaluation of daytime sleepiness in 115 subjects treated with Mandibular Lingual Repositioning Device - MLRD. Sleep Res 1996; V.25 p.191.

Current Claim: ESS and RDI intraoral appliance-induced clinical improvement is more robust than minSatO2..