(Chest. 2001;120:1455-1460.)
© 2001
American College of Chest Physicians
Relationship Between Craniofacial Abnormalities and Sleep-Disordered Breathing in Marfans Syndrome*
Peter A. Cistulli, MBBS, PhD, FCCP;
Helen Gotsopoulos, BDS and
Colin E. Sullivan, MBBS, PhD
*
From the Sleep Disorders Center (Drs. Cistulli and Gotsopoulos), Department of Respiratory Medicine, St George Hospital, University of New South Wales, Sydney, Australia; and the Sleep Disorders Center (Dr. Sullivan), Royal Prince Alfred Hospital, University of Sydney, Australia.
Correspondence to: Peter A. Cistulli, MBBS, PhD, FCCP, Sleep Disorders Center, Department of Respiratory Medicine, St George Hospital, Gray St, Kogarah 2217, NSW, Australia; e-mail: p.cistulli{at}unsw.edu.au
 |
Abstract
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Objectives: To examine the prevalence and nature of
craniofacial abnormalities in patients with Marfans syndrome and to
investigate the relationship between craniofacial abnormalities and
obstructive sleep apnea (OSA) severity in these patients.
Design: Cross-sectional.
Setting:
Marfans syndrome clinic in a tertiary teaching hospital.
Patients: Fifteen consecutive adult patients (7 men and 8
women; mean [± SD] age, 34.8 ± 13.2 years) who had Marfans
syndrome.
Measurements and results: Apneic status was
determined from standard overnight polysomnography testing.
Measurements from standardized lateral cephalometric radiographs were
compared to normative data. Thirteen patients had OSA, which was
defined as an apnea/hypopnea index (AHI) of > 5 episodes per hour
(mean AHI, 22 ± 15 episodes per hour). A high prevalence of
craniofacial abnormalities was found with significant gender
differences for some of the variables. Significant abnormalities for
the entire group were bimaxillary retrusion, a reduced maxillary
length, an increased total anterior face height, a long lower anterior
face height, an obtuse gonial angle, a steep mandibular plane, a
reduced posterior nasal airway height, a reduced posterior airway
space, and an increased distance from the mandibular plane to the hyoid
bone. Univariate analysis revealed significant correlations among the
total anterior face height, the upper anterior and posterior face
heights, the mandibular length, and AHI. There was a significant
correlation between the rank of the number of cephalometric
abnormalities per patient and AHI in those patients with OSA.
Conclusions: Craniofacial abnormalities are common in
patients with Marfans syndrome. The relationship between some
cephalometric parameters and apnea severity suggests a potential role
of craniofacial structure in the pathogenesis of OSA in these
patients.
Key Words: craniofacial abnormalities Marfans syndrome obstructive sleep apnea
 |
Introduction
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Marfans syndrome
is inherited as an
autosomal-dominant trait and is associated predominantly with
abnormalities of the following three major connective tissue systems:
the musculoskeletal; the cardiovascular; and the
ocular.1
2
3
More recently, the involvement of the skin,
the CNS, and the lungs has been reported.3
The diagnosis
is based on clinical criteria and family history.4
The
cause has been attributed to mutations in FBN1, the gene
that encodes fibrillin-1.4
The prevalence of Marfans
syndrome is estimated to be approximately 1 case per 10,000 persons in
the general population. The life expectancy of patients with Marfans
syndrome is greatly reduced, mainly due to aortic
complications.5
A high prevalence of obstructive sleep apnea (OSA) syndrome among
patients with Marfans syndrome has been reported.6
OSA
is a common disorder that is characterized by repetitive obstruction of
the upper airway during sleep. The typical patient with OSA is
middle-aged, centrally obese, and male.7
In marked
contrast, patients with Marfans syndrome are tall, thin, and
generally young. The reason for the high prevalence of OSA in these
patients is uncertain. Increased upper airway collapsibility during
sleep has been shown in this group, and it has been postulated that
this relates to the known connective tissue defect of the
syndrome.8
Furthermore, high nasal airway resistance has
been reported in patients with Marfans syndrome, and this appears to
be mediated by the characteristic maxillary constriction and high
arched palate that is associated with the syndrome.9
10
Marfans syndrome, like many other congenital syndromes, is associated
with various craniofacial abnormalities. Numerous studies have
suggested an important role of craniofacial abnormalities in the
development of OSA, especially among thin patients.11
Hence, an important possibility is that the craniofacial abnormalities
associated with Marfans syndrome result in a predisposition to OSA in
these patients. However, there has been little systematic evaluation of
the craniofacial skeleton in these patients to date. Therefore, the
aims of this study were to examine the prevalence and nature of
craniofacial abnormalities in patients with Marfans syndrome and to
investigate the relationship between craniofacial abnormalities and the
severity of OSA.
 |
Materials and Methods
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Patients
Fifteen consecutive adult patients (7 men and 8 women) with
Marfans syndrome presenting for routine follow-up at a specialist
Marfans syndrome clinic of a university teaching hospital were
studied. All patients fulfilled the diagnostic criteria for Marfans
syndrome.4
Informed consent was obtained from all
patients, and the study was approved by the ethics committee of our
institution.
Sleep Studies
All of the patients underwent standard nocturnal polysomnography
testing, as previously described.6
Sleep recordings were
scored in 30-s epochs and were staged according to standard
criteria.12
Calculated respiratory variables were
apnea/hypopnea index (AHI; ie, the number of apneas and
hypopneas per hour of sleep), and minimum oxygen saturation
(SaO2min). Airflow was
measured using nasal prongs attached to a pressure transducer. Apnea
was defined as a cessation of airflow for at least 10 s with
oxygen desaturation of > 4% and/or association with arousal.
Hypopnea was defined as a reduction in amplitude of airflow or
thoracoabdominal wall movement of > 50% of the baseline measurement
for > 10 s with an accompanying oxygen desaturation of at least 4%
and/or association with arousal. These respiratory events were defined
as obstructive if they occurred in association with continued
diaphragmatic electromyographic activity and thoracoabdominal wall
movement.
Cephalometry
Lateral cephalometric radiographs were taken using a
standardized technique.13
The subject was in the sitting
position with the Frankfort plane horizontal and the teeth in centric
occlusion. The distance from the mid-sagittal plane to the film was
standardized to 15 cm. The distance from the source to the mid-sagittal
plane was fixed at 152 cm. This produced a magnification of 1.1. The
cephalogram was taken at end-inspiration and without swallowing. All
radiographs were traced and interpreted by an experienced orthodontist
who had no knowledge of the patients clinical characteristics. Linear
and angular measurements were made from each tracing. The magnification
factor was taken into account to adjust all the linear measurements to
natural size. The reference landmarks and the lines used in the
analysis are shown in Figure 1
. The data were compared to population norms from Bhatia and
Leighton.14
Normative data for the posterior airway space
(PAS), the distance from the mandibular plane to the hyoid bone (MP-H),
and the length of the soft palate (ie, the distance from the
posterior nasal spine to the tip of the uvula [PNS-P]) were from
Guilleminault et al,15
and data for the posterior nasal
airway height (ie, the distance from the sphenoidale to the
posterior nasal spine [SE-PNS]) were from deBerry-Borowiecki et
al.16
The limits of normality were conservatively defined
as the 5th and 95th percentiles, using published normal values for the
various measurements.

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Figure 1.. Lines and angles on a schematic diagram of a
cephalometric tracing. PNS = posterior nasal spine; Gn = gnathion
(the most anterior inferior point on the contour of the bony chin
symphysis located by the bisector of the N-Pg and mandibular planes);
Ba = basion (the lowest point on the anterior border of the foramen
magnum); SE = sphenoidale (the point of intersection between the
greater wings of the sphenoid and the anterior cranial base, which is
considered to represent the junction between the ethmoid bone
anteriorly and the sphenoid bone posteriorly); H = the most superior
anterior point of the hyoid bone; MP-SN = angle between the line from
the Gn to the Me (mandibular plane) and the line from the S to the N;
N-S-Ba = angle between the N and the S and between the S and the Ba
(saddle angle); N-S-Gn (Y-axis angle) = angle between the N and the S
and the S and the Gn; Co-Go-Me (gonial angle) = angle between the Co
and the Go and between the Go and the Me; Co-Go = distance from Co to
the Go (mandibular ramus height); ANS-PNS = distance from the ANS to
the PNS (maxillary base length); TPFH = total posterior face height
(distance from the S to the Go); P = tip of the uvula.
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Statistical Analysis
Statistical comparisons between patients and normative data were
carried out by calculating the Z score (ie, Z = [patient
mean - normal mean]/SE of the difference between the means). The
statistical significance of the Z score was determined from statistical
tables for appropriate degrees of freedom. Statistical comparisons of
anthropometric and polysomnographic variables between male and female
patients were carried out by unpaired t tests. The
Mann-Whitney U test was used to make comparisons if the data
were not normally distributed. Univariate regression analysis was used
to determine which cephalometric variables correlated with the degree
of OSA, as reflected by the AHI and
SaO2min. Spearmans rank
correlation (r) was calculated to examine the relationship
between the rank of the number of cephalometric abnormalities per
patient and the AHI. Multiple linear regression was used to determine
which combination of cephalometric measurements correlated with
SaO2min. A p value < 0.05
was considered to be statistically significant. Descriptive statistics
are presented as the mean ± SD. Estimated means are presented as the
mean ± SEM.
 |
Results
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All patients were white and had the typical clinical features of
Marfans syndrome (ie, they were generally young, tall, and
thin; Table 1
). Men were significantly taller than women (188 ± 3 vs 175 ± 2
cm; p < 0.01) and had a greater neck circumference (37.0 ± 1.0 vs
34.0 ± 0.5 cm; p < 0.05). Thirteen of the 15 patients had OSA,
which was defined as an AHI more than five episodes per hour. The
severity of apnea in these patients was mild to moderate, with a mean
AHI of 22 ± 15 episodes per hour and a mean
SaO2min of 86 ± 7%.
Nine patients had an AHI of > 10 episodes per hour, and five patients
had an AHI of > 20 episodes per hour. Men had more severe OSA than
the women (mean AHI, 32 ± 5 vs 9 ± 1 episodes per hour,
respectively; p < 0.01; and mean
SaO2min, 83 ± 3% vs
91 ± 1%, respectively; p < 0.05).
Many of the cephalometric measurements were found to be abnormal in the
group as a whole compared to published normative data (Table 2
). The patients were found to have a mean of 8 of the 22 cephalometric
variables outside the limits of normality, with a range of 4 to 13
abnormalities per patient. The predominant abnormalities for the entire
group were as follows: retrusion of the maxilla and mandible
(ie, a reduced angle from the sella [S] to the nasion
[N] to the subspinale point [SNA] and a reduced angle from the S to
the N to the supramentale point [SNB] with a normal angle from the
deepest midline point on the maxillary alveolus between the anterior
nasal spine [ANS] and the maxillary alveolar crest [point A] to the
deepest midline point on the maxillary alveolus between the mandibular
alveolar crest and the pogonion [point B] [ANB]); an increased
angle from the mandibular plane to the anterior cranial base; an
increased angle between the condylion [Co] to the gonion [Go] and
the Go to the menton [Me] [ie, the gonial angle or
Co-Go-Me]; a reduced SE-PNS; a slightly reduced distance from the Co
to point A [Co-A], called the maxillary length; an increased MP-H; a
reduced PAS; an increased total anterior face height [TAFH]; and an
increased lower anterior face height [LAFH]). Men were found to have
significant reductions in SNA (70.6 ± 1.5 vs 82.0 ± 0.9 mm;
p < 0.0005) and SNB (70.0 ± 1.0 vs 79.7 ± 0.9 mm;
p < 0.0001) with a normal ANB. They also had a significantly reduced
Co-A (83.7 ± 1.4 vs 88.4 ± 0.8 mm; p < 0.01) and a
significantly increased distance from the S to the N (S-N)
(74.1 ± 1.1 vs 71.5 ± 0.6 mm; p < 0.05). Women had an
increased TAFH (118.6 ± 1.9 vs 111.9 ± 1.1 mm; p < 0.01).
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Table 2.. Comparison of Angular and Linear Cephalometric
Measurements Between Data for Marfans Syndrome Patients and Normative
Data*
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Univariate regression analysis revealed an association between some
cephalometric measurements and apnea severity as measured by AHI (Table 3
). There was also a significant correlation between PAS and
SaO2min (r = 0.65;
p < 0.01), but not with AHI. In the 13 patients with OSA, there was
a significant relationship between the rank of the number of
cephalometric abnormalities per patient and AHI (r = 0.65;
p < 0.05). However, the two patients without OSA also had a
significant number of abnormalities (seven in one patient and eight in
the other), but the PAS was significantly greater in these individuals
than in those with OSA (15.0 ± 1.0 vs 9.3 ± 0.9 mm; p < 0.05).
Multiple linear regression revealed that PAS and MP-H were both
independent predictors of
SaO2min, and together they
explained 67% of the variance in
SaO2min
(R2 = 0.67; p < 0.005). Neither
of these variables was a significant predictor of AHI. Body mass index
(BMI) was not an independent predictor of either AHI or
SaO2min in these patients.
 |
Discussion
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This cephalometric study of patients with Marfans syndrome
provides evidence that such patients have a high prevalence of
craniofacial abnormalities. The finding of a relationship between
indexes of apnea severity and various cephalometric measurements
suggests that these structural abnormalities are likely to play a role
in predisposing these individuals to OSA.
Various craniofacial abnormalities have been described in patients with
Marfans syndrome, although the literature on this topic has consisted
predominantly of case reports. Reported abnormalities include
dolichocephaly, maxillary constriction with a high arched palate,
maxillary and mandibular retrognathia, prognathia, and
macrocephaly.17
18
19
20
21
22
To our knowledge, the current study is
the first to examine airway measurements in addition to conventional
orthodontic measurements from cephalometric radiographs in patients
with Marfans syndrome and has confirmed the high prevalence of
abnormalities in these patients. All of the patients had at
least four of the assessed variables outside the limits of normality.
In keeping with other clinical aspects of this syndrome, there was a
degree of heterogeneity in the types and degrees of abnormalities that
were identified. In the total group, the significant abnormalities were
maxillary and mandibular retrusion with mandibular growth predominantly
vertical, a reduced maxillary length, an increased total anterior face
height, a long LAFH, an obtuse gonial angle, a steep mandibular plane,
a reduced posterior nasal airway height, a reduced PAS, and an
increased MP-H. Some of these findings are in accordance with those
previously described.
The observed cephalometric abnormalities are similar to those reported
in the general OSA population.11
Several studies have
found that various measurements correlate with the degree of OSA,
suggesting that structural abnormalities may play a role in its
pathophysiology. An increased MP-H23
24
and a decreased
PAS23
have been shown to be significant predictors of
apnea frequency. Davies and Stradling25
reported
significant correlations between the oxygen saturation dip rate and
hyoid position, soft palate length, and angle of the hard palate to the
spine. Using stepwise linear regression analysis, they found that neck
circumference and retroglossal space were the only significant
independent correlates. Similarly, apnea frequency has been found to
correlate with the logarithm of tongue volume, the position of the
mandible (SNB), the maxilla/mandible relationship (ANB), the overbite,
and BMI in a stepwise regression analysis.26
In the
present study, a univariate analysis revealed significant correlations
among the TAFH, the upper anterior face height (UAFH), the upper
posterior face height (UPFH), mandibular length (Co-Gn), and the AHI.
Furthermore, there was a significant correlation between the rank of
the number of cephalometric abnormalities per patient and AHI in the 13
patients with OSA. Similarly, multiple linear regression revealed that
MP-H and PAS explained 67% of the variability in
SaO2min levels, but they were not
independent predictors of AHI. The reduced PAS may be an explanation
for the increased prevalence of OSA in patients with Marfans syndrome
since the two Marfans syndrome patients without OSA had a normal or
increased PAS. Notably, BMI was not found to be a predictor of apnea
severity in these tall, thin individuals. This is consistent with a
proposed model of OSA in which the degree of craniofacial abnormality
in a patient determines the degree of obesity required to cause
OSA.27
28
Hence, at one end of the spectrum are patients
who are thin but have a significant degree of craniofacial abnormality,
such as in Marfans syndrome, and at the other end are obese
individuals without significant craniofacial abnormality.
The cause of the craniofacial abnormalities observed in patients with
Marfans syndrome is not yet clear. In particular, it is not clear
whether they are the direct result of the genetic abnormality or
whether environmental influences play a role. The patterns of
abnormalities observed in this study are known to be associated with
chronic airway obstruction during childhood development and are
collectively termed "long face syndrome" in the orthodontic
literature.29
30
31
Oral breathing consequent to nasal
obstruction has been implicated to cause modification of head posture,
which may influence facial development and dentofacial
growth.30
Animal studies further support the important
role of airway patency on facial development.32
Hence, it
is possible that the craniofacial abnormalities observed in patients
with Marfans syndrome are the result of chronic airway obstruction,
which is associated with mouth breathing. This is supported by the
observation that these patients have high nasal
resistance,9
which appears to be causally related to the
characteristic maxillary constriction and high-arched
palate.10
Moreover, this may have therapeutic implications
that are particularly relevant to Marfans syndrome, since expansion
of a narrow maxilla may improve nasal resistance33
and
sleep-disordered breathing.34
Our study has some potential limitations. We did not study concurrent
control subjects who were tall and thin but did not have Marfans
syndrome. The normative data we used from Bhatia and
Leighton14
are those of 20-year-old white subjects. There
is little significant change in the dentofacial complex after this age,
and therefore it is reasonable to use these data for adults. The data
for the two 16-year-old patients were compared to appropriate
age-matched data. Nevertheless, it will be necessary to study a group
of tall, thin control subjects (with and without airway obstruction) to
determine whether the abnormalities identified in this study are in
fact specifically related to Marfans syndrome or whether they are
related to other factors (eg, tall stature or airway
obstruction). The sample size was small, and therefore it is possible
that with a larger group greater heterogeneity in structural
abnormalities may have been detected.
In conclusion, this study has demonstrated a high prevalence of
craniofacial abnormalities in patients with Marfans syndrome. Coupled
with the finding that some of these variables correlated with apnea
severity, these data suggest that craniofacial abnormalities play a
potential role in the development of OSA in these patients who are tall
and thin, in contrast to the typical OSA population.
 |
Acknowledgements
|
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The authors gratefully acknowledge the assistance
of the staff of the Sleep Disorders Center and Dr. Richmond Jeremy from
the Marfan Clinic at Royal Prince Alfred Hospital. We thank Dr. Anthony
Pistolese for his analysis of the cephalometric radiographs.
 |
Footnotes
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Abbreviations: AHI = apnea/hypopnea index;
ANB = angle from the deepest midline point on the maxillary alveolus
between the anterior nasal spine and the maxillary alveolar crest to
the deepest midline point on the maxillary alveolus between the
mandibular alveolar crest and the pogonion; ANS = anterior nasal
spine; BMI = body mass index; CMP-H = distance from the mandibular
plane to the hyoid bone; Co = condylion; Co-A = slightly reduced
distance from the condylion to the deepest midline point on the
maxillary alveolus between the anterior nasal spine and the maxillary
alveolar crest; Co-Gn = distance from the Co to the Gn (mandibular
length); Co-Go-Me = angle between the condylion and the gonion and
the gonion and the menton; Go = gonion; LAFH = lower anterior face
height; Me = menton; MP-H = distance from the mandibular plane to
the hyoid bone; N = nasion; OSA = obstructive sleep apnea;
PAS = posterior airway space; PNS = posterior nasal spine;
PNS-P = the distance from the posterior nasal spine to the tip of the
uvula; point A = the deepest midline point on the maxillary alveolus
between the anterior nasal spine and maxillary alveolar crest; point
B = the deepest midline point between the mandibular alveolar crest
and the pogonion; S = sella;
SaO2min = minimum oxygen saturation;
SE-PNS = distance from the sphenoidale to the posterior nasal spine;
S-N = distance from the sella to the nasion; SNA = angle from sella
to nasion to the subspinale point; SNB = reduced angle from the sella
to the nasion to the supramentale point; TAFH = total anterior face
height; UAFH = upper anterior face height; UPFH = upper posterior face height
Supported by a National Health and Medical Research Council of
Australia Scholarship and the Australian Lung Foundation/Sensormedics Fellowship in Sleep Disorders (PAC).
Received for publication November 22, 2000.
Accepted for publication May 1, 2001.
 |
References
|
|---|
-
Hirst, AE, Gore, I (1973) Marfans syndrome: a review. Prog Cardiovasc Dis 16,187-198[CrossRef][Medline]
-
Pyeritz, RE, McKusick, VA (1979) The Marfan syndrome: diagnosis and management. N Engl J Med 300,772-777[ISI][Medline]
-
Pyeritz, RE (1986) The Marfan syndrome. Am Fam Physician 34,83-94
-
Pyeritz, RE (2000) The Marfan syndrome. Annu Rev Med 51,481-510[CrossRef][ISI][Medline]
-
Murdoch, JL, Walker, BA, Halpern, BA, et al (1972) Life expectancy and causes of death in the Marfan syndrome. N Engl J Med 286,804-808
-
Cistulli, PA, Sullivan, CE (1993) Sleep-disordered breathing in Marfans syndrome. Am Rev Respir Dis 147,645-648[ISI][Medline]
-
Grunstein, RR, Wilcox, I, Yang, TS, et al (1993) Snoring and sleep apnoea in men: association with central obesity and hypertension. Int J Obes 17,533-540
-
Cistulli, PA, Sullivan, CE (1995) Sleep apnea in Marfans syndrome: increased upper airway collapsibility during sleep. Chest 108,631-635[Abstract/Free Full Text]
-
Cistulli, PA, Richards, GN, Palmisano, RG, et al (1996) Influence of maxillary constriction on nasal resistance and sleep apnea severity in patients with Marfans syndrome. Chest 110,1184-1188[Abstract/Free Full Text]
-
Cistulli, PA, Sullivan, CE (2000) Influence of maxillary morphology on nasal airway resistance in Marfans syndrome. Acta Otolaryngol 120,410-413[Medline]
-
Cistulli, PA (1996) Craniofacial abnormalities in obstructive sleep apnoea: implications for treatment. Respirology 3,167-174
-
Rechtschaffen A, Kales A. A manual of standardized terminology, techniques and scoring system for sleep stages of human subjects. Los Angeles, CA: Brain Information Service/Brain Research Institute, University of California at Los Angeles, 1968; National Institutes of Health publication No. 204
-
Broadbent, BH, Broadbent, BH, Jr, Golden, WH (1975) Bolton standards of dentofacial developmental growth. St. Mosby Louis, MO.
-
Bhatia, SN, Leighton, BC (1993) A manual of facial growth: a computer analysis of longitudinal cephalometric growth data. Oxford University Press New York, NY.
-
Guilleminault, C, Riley, R, Powell, N (1984) Obstructive sleep apnea and abnormal cephalometric measurements: implications for treatment. Chest 86,793-794[Abstract/Free Full Text]
-
deBerry-Borowiecki, B, Kukwa, A, Blanks, RH (1988) Cephalometric analysis for diagnosis and treatment of obstructive sleep apnea. Laryngoscope 98,226-234[ISI][Medline]
-
Gazit, E, Lieberman, M (1981) Severe maxillary arch constriction in a patient with Marfans syndrome: report of a case. ASDC J Dent Child 48,292-293[Medline]
-
Crosher, R, Homes, A (1988) A Marfan syndrome: dental problems and management. Dent Update 15,120-122[Medline]
-
Sellitti, F, Pulella, G, Minerva, G (1989) Aspetti oro-maxillo-facciali dell sindrome di Marfan. Arch Stomatol (Napoli) 30,409-420[Medline]
-
Motohashi, N (1985) Cranial dysmorphology in syndromes associated with abnormal physical growth. J Craniofac Genet Dev Biol 1,211-225
-
Poole, AE (1989) Craniofacial aspects of the Marfan syndrome. Birth Defects Orig Artic Ser 25,73-81
-
Westling, L, Mohlin, B, Bresin, A (1998) Craniofacial manifestations in the Marfan syndrome: palatal dimensions and a comparative cephalometric analysis. J Craniofac Genet Dev Biol 18,211-218[Medline]
-
Partinen, M, Guilleminault, C, Quera-Salva, M, et al (1988) Obstructive sleep apnea and cephalometric roentgenograms: the role of anatomic upper airway abnormalities in the definition of abnormal breathing during sleep. Chest 93,1199-1205[Abstract/Free Full Text]
-
Yildirim, N, Fitzpatrick, MF, Whyte, KF, et al (1991) The effect of posture on upper airway dimensions in normal subjects and in patients with the sleep apnea/hypopnea syndrome. Am Rev Respir Dis 144,845-847[ISI][Medline]
-
Davies, RJO, Stradling, JR (1990) The relationship between neck circumference, radiographic pharyngeal anatomy, and obstructive sleep apnea. Eur Respir J 3,509-514[Abstract]
-
Lowe, AA (2000) Oral appliances for sleep breathing disorders. Kryger, MH Roth, T Dement, WC eds. Principles and practice of sleep medicine 3rd ed. ,929-939 WB Saunders Philadelphia, PA.
-
Ferguson, KA, Ono, T, Lowe, AA, et al (1995) The relationship between obesity and craniofacial structure in obstructive sleep apnea. Chest 108,375-381[Abstract/Free Full Text]
-
Tsuchiya, M, Lowe, AA, Pae, EK, et al (1992) Obstructive sleep apnea subtypes by cluster analysis. Am J Orthod Dentofacial Orthop 101,533-542[ISI][Medline]
-
Linder-Aronson, S, Backstrom, A (1960) A comparison between mouth and nose breathers with respect to occlusion and facial dimensions. Odontol Revy 11,343
-
Solow, B, Siersbaek-Nielson, S, Greve, E (1984) Airway adequacy, head posture, and craniofacial morphology. Am J Orthod 86,214-223[CrossRef][ISI][Medline]
-
Warren, DW (1990) Effect of airway obstruction upon facial growth. Otolaryngol Clin North Am 23,699-712[Medline]
-
Harvold, EP, Vargervik, K, Chierici, G (1973) Primate experiments on oral sensation and dental malocclusion. Am J Orthod 69,494-508
-
Timms, DJ (1974) Some medical aspects of rapid maxillary expansion. Br J Orthod 1,127-132[Medline]
-
Cistulli, PA, Palmisano, RG, Poole, MD (1998) Effect of rapid maxillary expansion in obstructive sleep apnea. Sleep 21,831-835[Medline]
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