PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (329575)

Clipboard (0)
None

Related Articles

1.  Cephalometric measurements in snorers, non-snorers, and patients with sleep apnoea. 
Thorax  1991;46(6):419-423.
Cephalometry is often used to assess patients with sleep apnoea but whether these measurements differ from those in non-apnoeic snorers and how they are influenced by age is not clear. Cephalometric radiographs of patients with sleep apnoea were compared with those of snorers without sleep apnoea and those of non-snorers. Fifty two snorers with suspected sleep apnoea had a conventional sleep study and were divided into two groups: those with an apnoea-hypopnoea index greater than 10/h (n = 40, sleep apnoea group) and those whose apnoea-hypopnoea index was 10/h or less (n = 12, snorer group). The cephalometric measurements in these patients were compared with those of 34 non-snoring control subjects. Controls were subdivided into two groups: control group 1 included 17 subjects similar in age to the sleep apnoea and snorer groups (mean (SD) age 50.0 (10.9), 50.7 (9.4), and 50.6 (9.7) years); control group 2 included 15 young men (25.4 (2.6) years). The distance from the mandibular plane to the hyoid bone (MP-H) and the length of the soft palate were greater in the patients with sleep apnoea (28.7 (7.8) and 43.6 (5.0) mm) than in the snorers (23.7 (4.2) and 40.3 (4.9 mm). The MP-H was similar in snorers and age matched control subjects, but was significantly greater in the older than in the younger control subjects (22.1 (6.1) vs 17.0 (6.8]. The soft palate was longer in subjects who snored (both sleep apnoea patients and snorers) than in control subjects. The MP-H distance significantly correlated with age for all subjects (snorers and controls) and for the control subjects alone. This study shows that non-apnoeic snorers have cephalometric abnormalities that differ from those of patients with sleep apnoea and that cephalometric values are influenced by the subject's age.
Images
PMCID: PMC463188  PMID: 1858079
2.  Snoring as a risk factor for disease: an epidemiological survey. 
In a study conducted in four family practice units in Toronto, Canada, 2001 subjects reported on snoring and medical conditions in members of their households. For spouses the prevalence of snoring increased with age up to the seventh decade, with a higher prevalence of nearly 85% in husbands. For 11 medical problems an association existed between snoring, its frequency, and the presence of the condition. This association continued when the data were corrected for sex, age, and marital state. For hypertension both men and women who snored between the fifth and 10th decades had a twofold increase over non-snorers. The prevalence of heart disease and other conditions, except for diabetes and asthma, also increased in snorers in this age group. When corrected for smoking and obesity the association between snoring, hypertension, and heart disease persisted. These findings extend those of Lugaresi et al, and if they could be confirmed snoring as a risk factor for conditions other than sleep apnoea and sleep disorders might be considered. Methods of alleviating the acoustic annoyance of snoring may also provide direct medical benefits.
PMCID: PMC1417471  PMID: 3928056
3.  Association between self reported snoring, STOP questionnaire and postoperative pulmonary complications in patients submitted to ortophaedic surgery 
Background
Obstructive sleep apnea (OSA) may increase perioperative complications. The aim of this study was to determine the relationship among postoperative pulmonary complication, snoring and STOP questionnaire in patients with ortophaedic surgery.
Methods
1,406 consecutive records of patients who had undergone elective ortophaedic surgery during the period January 2005-December 2008 were investigated retrospectively. Demographic information, sleep symptoms, STOP questionnaire, comorbidities and outcome data were collected.
Results
There were 289 (20.5%) snorers and 1,117 (79.5%) non-snorers in the study group. There was no significant difference between snorer and non-snorer patients (p > 0.05) in the prevalence of pneumonia and respiratory failure. But in snorer patients the rate of postoperative atelectasis was significantly higher than in non-snorer group (p < 0.0001). The STOP Questionnaire was given to 1,406 patients and 147 (10.4%) out of them were classified at high risk of OSA. There was no significant difference in the prevalence of pneumonia and respiratory failure between low and high risk group (p > 0.05). However, in high risk patients the occurrence of postoperative atelectasis was significantly higher than in low risk group (p < 0.0001).
Conclusion
Postoperative atelectasis was significantly more prevalent in the high risk group according to STOP questionnaire.
doi:10.1186/2049-6958-8-3
PMCID: PMC3598696  PMID: 23331468
Atelectasis; Obesity; Orthopedic surgery; Sleep apnea; STOP questionnaire
4.  Snoring as a risk factor for ischaemic heart disease and stroke in men. 
The association of snoring with ischaemic heart disease and stroke was studied prospectively in 4388 men aged 40-69. The men were asked, in a questionnaire sent to them, whether they snored habitually, frequently, occasionally, or never. Hospital records and death certificates were checked for the next three years to establish how many of the men developed ischaemic heart disease or stroke: the numbers were 149 and 42, respectively. Three categories of snoring were used for analysis: habitual and frequent snorers (n = 1294), occasional snorers (n = 2614), and non-snorers (n = 480). The age adjusted relative risk of ischaemic heart disease between habitual plus frequent snorers and non-snorers was 1.91 (p less than 0.01) and for ischaemic heart disease or stroke, or both, 2.38 (p less than 0.001). There were no cases of stroke among the non-snorers. Adjustment for age, body mass index, history of hypertension, smoking, and alcohol use did not significantly decrease the relative risks, which were 1.71 (p greater than 0.05) for ischaemic heart disease and 2.08 (p less than 0.01) for ischaemic heart disease and stroke combined. At the beginning of follow up in 1981, 462 men reported a history of angina pectoris or myocardial infarction. For them the relative risk of ischaemic heart disease between habitual plus frequent snorers and non-snorers was 1.30 (NS); for men without previous ischaemic heart disease 2.72 (p less than 0.05). Snoring seems to be a potential determinant of risk of ischaemic heart disease and stroke.
PMCID: PMC1245038  PMID: 3101779
5.  Heart rate variability in non-apneic snorers and controls before and after continuous positive airway pressure 
Background
We hypothesized that sympathetic nervous system activity (SNSA) is increased and parasympathetic nervous system activity (PNSA) is decreased during non-rapid eye movement (NREM) sleep in non-apneic, otherwise healthy, snoring individuals compared to control. Moreover, we hypothesized that these alterations in snoring individuals would be more evident during non-snoring than snoring when compared to control.
Methods
To test these hypotheses, heart rate variability was used to measure PNSA and SNSA in 11 normotensive non-apneic snorers and 12 control subjects before and 7-days after adapting to nasal continuous positive airway pressure (nCPAP).
Results
Our results showed that SNSA was increased and PNSA was decreased in non-apneic snorers during NREM compared to control. However, these changes were only evident during the study in which snoring was eliminated with nCPAP. Conversely, during periods of snoring SNSA and PNSA were similar to measures obtained from the control group. Additionally, within the control group, SNSA and PNSA did not vary before and after nCPAP application.
Conclusion
Our findings suggest that long-lasting alterations in autonomic function may exist in snoring subjects that are otherwise healthy. Moreover, we speculate that because of competing inputs (i.e. inhibitory versus excitatory inputs) to the autonomic nervous system during snoring, the full impact of snoring on autonomic function is most evident during non-snoring periods.
doi:10.1186/1471-2466-5-9
PMCID: PMC1208915  PMID: 16048652
6.  COMPARISON OF CBCT PARAMETERS AND SLEEP QUESTIONNAIRES IN SLEEP APNEA PATIENTS AND CONTROLS 
Objective
To compare the Cone-Beam Computerized Tomography (CBCT) scan measurements between patients with Obstructive Sleep Apnea (OSA) and snorers to develop a prediction model for OSA based on CBCT imaging and the Berlin Questionnaire.
Materials and methods
80 subjects (46 OSA patients with Apnea-Hypoapnea Index [AHI]≥ 10 and 34 snorers AHI<10 based on ambulatory somnographic assessment) were recruited through flyers and mail at USC School of Dentistry and at a private practice. Each patient answered the Berlin Questionnaire, and was imaged with CBCT in supine position. Linear and volumetric measurements of the upper airway were performed by one blinded operator and multivariate logistic regression analysis was used to identify risk factors for OSA.
Results
OSA patients were predominantly male, older, had a larger neck size and larger Body Mass index than the snorers. The minimum cross-sectional area of the upper airway and its lateral dimension were significantly smaller in the cases. Airway uniformity defined as the minimum cross-sectional area divided by the average area was significantly smaller in the OSA patients.
Conclusions
Age>57 years, male gender, a “high risk” Berlin Questionnaire and narrow upper airway lateral dimension (<17mm) were identified as significant risk factors for OSA. The results of this study indicate that 3-dimensional CBCT airway analysis could be used as a tool to assess the presence and severity of OSA. The presence and severity (as measured by the RDI) of OSA is associated with a narrow lateral dimension of the airway, increasing age, male gender, and the Berlin questionnaire.
doi:10.1016/j.tripleo.2009.09.033
PMCID: PMC2900776  PMID: 20123412
Cone-Beam Computerized Tomography; Obstructive sleep apnea; Upper airway; Volume
7.  Prevalence of Sleep Abnormalities and Their Association with Metabolic Syndrome among Asian Indians: Chennai Urban Rural Epidemiology Study (CURES – 67) 
Objective
To estimate the prevalence of sleep abnormalities and their association with glucose intolerance and metabolic syndrome (MS) in the normal-weight urban South Indian population.
Methods
This population-based, cross-sectional study was carried out in 358 subjects aged 20–76 years randomly selected from the Chennai Urban Rural Epidemiology Study in South India. A validated questionnaire assessing various sleep abnormalities (snoring, daytime sleepiness, lack of refreshing sleep, and number of hours of sleep) was administered. All subjects underwent an oral glucose tolerance test, and anthropometric biochemical measurements were obtained to assess cardiometabolic risk factors including glucose intolerance. Diabetes risk was assessed using a previously validated Indian Diabetes Risk Score (IDRS).
Results
The overall prevalence of snoring and daytime sleepiness was 40% and 59%, respectively. Snorers were more male, older, smokers, and had higher levels of cardiometabolic risk factors. Subjects with daytime sleepiness had higher body mass index (BMI) and abdominal obesity. Both snoring (50.9% vs 30.2%, p < 0.001) and daytime sleepiness (68% vs 49.7%, p < 0.001) were more prevalent among subjects with impaired glucose metabolism compared to those with normal glucose metabolism. Both sleep measures were associated with higher diabetes risk scores, as assessed by the IDRS (snoring: trend χ2, 11.14, p = 0.001; daytime sleepiness: trend χ2, 5.12, p = 0.024). Metabolic syndrome was significantly associated with snoring even after adjusting for age, sex, family history of diabetes, physical activity, smoking, and alcohol.
Conclusion
The prevalence of snoring and daytime sleepiness is high among urban South Indians and these two sleep measures are associated with glucose intolerance, MS, and higher diabetes risk scores.
PMCID: PMC3005066  PMID: 21129351
sleep abnormalities; snoring; daytime sleepiness; cardiometabolic risk factors; metabolic syndrome; Asian Indians
8.  Effect of body position on tongue posture in awake patients with obstructive sleep apnoea 
Thorax  1997;52(3):255-259.
BACKGROUND: Snoring and obstructive sleep apnoea (OSA) are worse or may only occur in the supine position. The effect of body position on upper airway size has been reported, but the effect on tongue posture has not previously been examined. METHODS: Detailed measurements were made of tongue posture from upright and supine lateral cephalograms on 24 men with OSA and 13 men with non-apnoeic snoring matched for age, body mass index, and craniofacial skeletal pattern. Patients with OSA had apnoea/hypopnoea indices (AHI) of > 50/hour and/or apnoea indices (AI) of > 25/hour while non-apnoeic snorers had AHI of < 10/hour and AI of < 5/hour. RESULTS: In non-apnoeic snorers the tongue depth measurements for the superior-posterior portion of the tongue were larger in the supine than in the upright position (p < 0.05). There was no significant difference in tongue depth measurements between the upright and the supine position in the patients with OSA. CONCLUSIONS: When awake patients with OSA move from the upright to the supine position they maintain their upright tongue posture which may tend to protect against upper airway collapse secondary to the increased gravitational load on the tongue. In contrast, when awake non-apnoeic snorers move from the upright to the supine position a significant dorsal movement in the superior-posterior portion of the tongue is observed. 



PMCID: PMC1758500  PMID: 9093342
9.  Intranasal corticosteroid therapy for obstructive sleep apnoea in patients with co-existing rhinitis 
Thorax  2004;59(1):50-55.
Methods: We evaluated an intranasal corticosteroid, fluticasone propionate, in 24 consecutive snorers with associated rhinitis using a randomised, placebo controlled, crossover design. Patients underwent polysomnography, snoring noise, and NAR measurements at baseline and after each 4 week treatment period.
Results: Twenty three patients completed the protocol and were divided into an apnoeic group (group A; 13 patients) and a non-apnoeic snoring group (group S; 10 patients) based on an apnoea-hypopnoea frequency (AHI) of ⩾10/h or <10/h. AHI was significantly lower following treatment with fluticasone than with placebo in the total population (median (quartile range) 11.9 (22.6) v 20 (26.3); p<0.05) and in group A (23.3 (21.3) v 30.3 (31.9); p<0.05). Median (95% confidence interval) within subject differences for AHI were -3.2 (-17.7 to -0.2) in the total population and -6.5 (-29.5 to 1.8) in group A. NAR was also lower on fluticasone (2.74 (1.21) v 3.27 (1.38), p<0.01), within subject difference being -0.45 (95% CI -0.87 to -0.21). The changes in AHI and NAR in group A were significantly correlated (r = 0.56; p<0.05). Snoring noise and sleep quality were unchanged but daily diary records indicated subjective improvements in nasal congestion and daytime alertness with fluticasone (p<0.02).
Conclusions: Intranasal fluticasone is of benefit to some patients with OSAS and rhinitis. The data suggest that this form of nasal obstruction may contribute to the pathophysiology of OSAS.
PMCID: PMC1758841  PMID: 14694248
10.  Effect of Bedtime Ethanol on Total Inspiratory Resistance and Respiratory Drive in Normal Nonsnoring Men 
We have previously reported that bedtime ethanol (2.0 ml/kg of 100 proof vodka) increases upper airway closing pressure in males who habitually snored but were otherwise healthy. We also observed that some of these snorers developed obstructive apneas. To explore this phenomenon in more detail, we measured the inspiratory resistance (R1) and respiratory drive after bedtime ethanol in 10 nonobese men (ages 23 to 33) with no history of snoring. Subjects went to bed wearing a tightly fitting valved mask over the nose and mouth that allowed measurement of inspiratory and expiratory flow, pressure in the mask, and endtidal CO2. We measured R1 by calculating the pressure difference between the mouth and a balloon positioned in the midesophagus. Respiratory drive was quantified by the inspiratory occlusion pressure (P0.1), the ventilatory response to hyperoxic hypercapnia (ΔV̇E/ΔPETCO2), and the ventilatory response to isocapnic hypoxia (ΔV̇E/ΔSaO2). Measurements were made during waking and during stage 2 NREM sleep on two nights: (1) when the subjects drank 1.5 ml/kg of 100 proof vodka in orange juice over a 30-min period 15-45 min before lights out and (2) when the orange juice contained less than 0.1 ml of vodka floating on the top. Eight of the nine men in whom we had technically adequate measurements showed a rise in R1 during NREM sleep above the waking level on both control and ethanol nights and the sleeping R1 was greater on the ethanol than on the control night. There was a tendency for P0.1 to be higher during sleep and greater on the ethanol night, suggesting that the neural output to the respiratory muscles was not depressed and may have been stimulated by the inspiratory “loading” secondary to the increased R1. The hypercapnic response was significantly depressed during sleep. Whereas the response tended to be less on the ethanol than on the control night, the difference was not significant. The hypoxic response showed little change from waking to sleeping and no significant change with ethanol. We speculate that inspiratory loading due to increased upper airway resistance tends to stimulate respiratory drive and thereby partially offsets the depressant effect of ethanol on the central respiratory chemoreceptors.
PMCID: PMC2426749  PMID: 8488964
Ethanol; Respiratory Drive; Sleep; Upper Airway Resistance
11.  Bedtime Ethanol Increases Resistance of Upper Airways and Produces Sleep Apneas in Asymptomatic Snorers 
Nasal continuous positive airway pressure (nasal CPAP) and polysomnography were used to analyze the time course of the effect of bedtime ethanol on resistance of upper airways and on the number of respiratory pauses during sleep. On one night, six asymptomatic nonalcoholic male snorers drank 2 ml/kg of 100 proof vodka mixed in orange juice (ethanol dose, 0.79 gm/kg, giving a peak blood alcohol level of 71.8 ± 33.3 mg/dl). On a second night they received a placebo (1–2 drops of vodka floated on top of the orange juice). We measured (a) the minimum nasal CPAP required to eliminate snoring, (b) the number of hypopneas and apneas during each hour of sleep and (c) the arterial oxygen saturation (SaO2) by ear oximetry. On the alcohol night there was a significant increase in the CPAP pressure required to eliminate snoring (placebo 4.8 ± 1.7 cm H2O, alcohol 6.2 ± 1.5 cm H2O). The number of respiratory events per hour of sleep (apnea index) was 7.5 ± 2.1 for ethanol nights versus 3.8 ± 2.7 for placebo nights (p < 0.0125). An apnea index of greater than 5 is generally considered abnormal. There was no significant difference in the number of desaturation events (declines of 4% or more in the SaO2) or in the mean SaO2, but the minimum SaO2 was significantly lower on the ethanol night (placebo 89.8% ± 1.6, alcohol 86.8% ± 2.7, p < 0.05). The effect of this dose of alcohol on airway resistance was most pronounced during the first 2 hr after ingestion.
PMCID: PMC2336897  PMID: 3064641
12.  Does the Oropharyngeal Fat Tissue Influence the Oropharyngeal Airway in Snorers? Dynamic CT Study 
Korean Journal of Radiology  2004;5(2):102-106.
Objective
The aim of this study was to determine if snorers have a narrower oropharyngeal airway area because of fat infiltration, and an elevated body mass index.
Materials and Methods
Ten control subjects and 19 patients that snored were evaluated. We obtained 2-mm-thick axial CT scan images every 0.6 seconds during expiration and inspiration at the same level of the oropharynx. We selected the largest and the smallest oropharyngeal airway areas and found the differences. From the slice that had the smallest oropharyngeal airway area, the thickness of the parapharyngeal and subcutaneous fat was measured. The measurements from the left and right side were added together and single values for parapharyngeal and subcutaneous fat tissue thickness were then found.
Results
The conventional measure of body mass index was significantly higher in the snorers (p < 0.05). The difference in the smallest oropharyngeal airway area between snorers and the controls was statistically significant (p < 0.01). The average difference between the largest and the smallest oropharyngeal area in the control group and the snorer group was statistically significant (p < 0.05). There was no significant difference in the largest oropharyngeal airway area, the total subcutaneous fat width and the total parapharyngeal fat width between snorers and control subjects (p > 0.05).
Conclusion
We concluded that the oropharyngeal fat deposition in snorers is not an important factor, and it does not predispose a person to the upper airway narrowing.
doi:10.3348/kjr.2004.5.2.102
PMCID: PMC2698137  PMID: 15235234
Computed tomography (CT); Computed tomography (CT), functional imaging; Neek, CT; Neck, anatomy
13.  An Experimental Method for Stereolithic Mandible Fabrication and Image Preparation 
Reproduction of anatomical structures by rapid prototyping has proven to be a valid adjunct for craniofacial surgery, providing alternative methods to produce prostheses and development of surgical guides. The aim of this study was to introduce a methodology to fabricate asymmetric human mandibles by rapid prototyping to be used in future studies for evaluating mandibular symmetries. Stereolithic models of human mandibles were produced with varying amounts of asymmetry in the condylar neck, ramus and body of the mandible by means of rapid prototyping. A method for production of the synthetic mandibles was defined. Model preparation, landmark description and development of the experimental model were described. A series of synthetic mandibles ranging in asymmetry were accurately produced from a scanned human mandible. A method for creating the asymmetries, fabricating, coating and landmarking the synthetic mandibles was formulated. A description for designing a reproducible experimental model for image acquisition was also outlined. Production of synthetic mandibles by stereolithic modeling is a viable method for creating skeletal experimental models with known amounts of asymmetry.
doi:10.2174/1874120700701010004
PMCID: PMC2701083  PMID: 19662121
Biomedical engineering; Rapid prototyping; Image processing; Stereolithic mandible models.
14.  Assessment of chronic snorers. 
Snorers represent a heterogenous group that require adequate assessment before recommending surgical treatment. There are unfortunately no specific features either in the history or physical examination that might predict those chronic snorers with obstructive sleep apnoea. We have used trained observation together with pulse oximetry ('sleep screening') and fibreoptic nasendoscopy with Muller manoeuvre in our unit to assess snorers. This combination is a reliable means of distinguishing apnoeic patients from simple snorers and determining the level of the obstructing segment. We report our experience in using these methods in the management of 71 chronic snorers. We stress the value of conservative management, and emphasize that obesity, habitual alcohol ingestion and nasal obstruction should be corrected before embarking on pharyngeal surgery.
PMCID: PMC1292685  PMID: 2380965
15.  Habitual snoring with and without obstructive sleep apnoea: the importance of cephalometric variables. 
Thorax  1992;47(3):157-161.
BACKGROUND: The obstructive sleep apnoea syndrome is characterised by an increased apnoea-hypopnoea index and a reduction in the minimal arterial oxygen saturation (SaO2) values during sleep. The extent to which these variables can be predicted by cephalometric and otorhinolaryngological variables was tested. METHODS: One hundred consecutive habitual snorers (84% male), with a mean (SD) age of 50.1 (10.1) years, were studied. The 45 patients with less severe sleep apnoea, with an apnoea-hypopnoea index of 10 or less (group A), were compared with the 55 with an index above 10 (group B). RESULTS: Body mass index, some cephalometric variables, and some otorhinolaryngological variables differed significantly between group A and group B, in particular the soft tissue measures PNS-P (posterior nasal spine to palate), MP-H (mandibular plane to hyoid bone), degree of oropharynx stenosis, and tongue size. In a multiple regression correlation analysis MP-H, SNB (angle from sella to nasion to subspinale point), SNA (angle from sella to nasion to supramentale point), PAS (posterior airway space), tongue size, and body mass index contributed significantly to the equation explaining the severity of sleep apnoea. Nevertheless, these variables together explained only 33% of the variance of the apnoea-hypopnoea index in the total sample; they were more important for patients with moderate to severe stages of the disease. CONCLUSION: The lack of association between cephalometric variables and mild sleep apnoea suggests that the differences in these variables (soft tissue measures) may be the consequence rather than the cause of habitual snoring and the obstructive sleep apnoea syndrome.
PMCID: PMC1021003  PMID: 1519191
16.  Snoring in children: association with respiratory symptoms and passive smoking. 
BMJ : British Medical Journal  1989;299(6714):1491-1494.
OBJECTIVE--To investigate the relation between snoring and various respiratory symptoms and passive parental smoking. DESIGN--Data were collected by questionnaire. SETTING--Primary schools in Guardiagrele and Francavilla in the Abruzzi region in central Italy. SUBJECTS--1615 Children aged 6-13 years were categorised according to whether they snored often; occasionally apart from with colds; only with colds; or never. RESULTS--118 Children were habitual snorers and 137 were reported to snore apart from when they had colds. Never snorers (n = 822) were significantly older than children in other categories. Snoring was significantly associated with rhinitis, production of cough and sputum, previous tonsillectomy, and passive parental smoking. Of the habitual snorers, 82 were exposed to passive smoking. The prevalence of habitual snoring increased significantly with the number of cigarettes smoked by parents (from 5.5% in never smoking [corrected] households to 8.8% in heavy smoking households). CONCLUSIONS--Snoring is quite common in children. The dose-effect relation of smoking and snoring shown in this study adds weight to a further adverse effect of parental smoking on children's health.
PMCID: PMC1838384  PMID: 2514859
17.  The effect of mandibular buccal tilting on the accuracy of posterior mandibular spiral tomographic images: An in vitro study 
Dental Research Journal  2011;8(Suppl1):S100-S104.
Background:
Accurate measurement of the height and buccolingual thickness of available bone has a significant role in dental implantology. The shadow of ramus on the mandibular second molar region disturbs the sharpness of conventional tomographic images. The aim of this study was to evaluate the effect of transferring the shadow of ramus from the center of the focal plane, by changing the position of mandible, on the sharpness of the posterior mandibular region.
Materials and Methods:
In this experimental study, we used 10 dry human mandibles. Three metal balls were mounted on the midline and mandibular second molar regions bilaterally. Standard panoramic and tomographic images were taken. Then, the mandible was tilted buccaly for 8° – compensating the normal lingual inclination of the mandibular ridge and teeth on this region – and tomographic images were taken again. The height and thickness of bone were measured on the images and then compared with the real amounts measured directly on mandibles. Also, the sharpness of mandibular canals was compared between the two tomographic methods. Findings were analyzed with repeated measured ANOVA test (P<0.05).
Results:
The height of mandibular bone, on the images of the tilted tomography technique was more accurate compared to standard (P<0.001), but standard tomography had more accuracy in estimating the buccolingual thickness at the half-height point. Regarding the sharpness of mandibular canals, we found no significant differences between two tomographic methods.
Conclusion:
Buccal tilting is recommended when measuring the bone height is more important, but routine standard tomography is preferred when the thickness is requested.
PMCID: PMC3556287  PMID: 23372586
Buccal tilt; mandible; positioning; spiral tomography
18.  The effects of high dose and highly fractionated radiation on distraction osteogenesis in the murine mandible 
The ability of irradiated tissue to support bony growth remains poorly defined, although there are anecdotal cases reported showing mixed results for the use of mandibular distraction osteogenesis after radiation for head and neck cancer. Many of these reports lack objective measures that would allow adequate analysis of outcomes or efficacy. The purpose of this experiment was to utilize a rat model of mandibular distraction osteogenesis after high dose and highly fractionated radiation therapy and to evaluate and quantify distracted bone formation under these conditions. Male Sprague–Dawley rats underwent 12 fractions of external beam radiation (48 Gray) of the left mandible. Following a two week recovery period, an external frame distractor was applied and gradual distraction of the mandible was performed. Tissue was harvested after a twenty-eight day consolidation period. Gross, radiologic and histological evaluations were undertaken. Those animals subjected to pre-operative radiation showed severe attenuation of bone formation including bone atrophy, incomplete bridging of the distraction gap, and gross bony defects or non-union. Although physical lengthening was achieved, the irradiated bone consistently demonstrated marked damaging effects on the normal process of distraction osteogenesis. This murine model has provided reliable evidence of the injurious effects of high dose radiation on bone repair and regeneration in distraction osteogenesis utilizing accurate and reproducible metrics. These results can now be used to assist in the development of therapies directed at mitigating the adverse consequences of radiation on the regeneration of bone and to optimize distraction osteogenesis so it can be successfully applied to post-oncologic reconstruction.
doi:10.1186/1748-717X-7-151
PMCID: PMC3494577  PMID: 22958832
19.  Mandibular mechanics following osteotomy and appliance placement. II. Bone strain on the body and condylar neck 
Purpose
The purpose of this investigation was to determine if the mechanical environment of the mandible is changed by osteotomy and fixation, as assessed by the measurement of bone strain on the condylar neck and mandibular corpus.
Materials and Methods
Immediately following unilateral mandibular osteotomy and distractor placement, strain gauges were attached directly to the corpus and condylar neck in a sample of domestic pigs. Bone strains were recorded during mastication and muscle stimulation. Comparisons of principal strain magnitudes and orientations were made between sides and between the osteotomy sample and a control database.
Results
The animals preferred to chew on the non-osteotomy side. Corpus strains were higher for osteotomy-side chewing but were comparable to the control database, regardless of chewing side. For the condyle, compared to the control database and the non-osteotomy side, the osteotomy side was underloaded in compression. Furthermore, the orientation of compressive strain was highly variable and more horizontally oriented than that of control and non-osteotomy condyles. Stimulation of the masseter and medial pterygoid loaded the mandible to normal levels.
Conclusions
Masticatory behavior was altered, probably as a combined result of disruption to the occlusion, changes in muscle recruitment, and probable loss of sensory feedback. However, neither these changes nor damage to the muscles explain the decrease and reorientation of compressive strain on the condylar neck. Alternatively, the modified strain pattern could have arisen from positional instability of the proximal bone fragment.
doi:10.1016/j.joms.2005.12.007
PMCID: PMC1810236  PMID: 16546641
condyle; mandible; bone strain; distraction osteogenesis; pig
20.  Mechanisms used to restore ventilation after partial upper airway collapse during sleep in humans 
Thorax  2007;62(10):861-867.
Background
Most patients with obstructive sleep apnoea (OSA) can restore airflow after an obstructive respiratory event without arousal at least some of the time. The mechanisms that enable this ventilatory recovery are unclear but probably include increased upper airway dilator muscle activity and/or changes in respiratory timing. The aims of this study were to compare the ability to recover ventilation and the mechanisms of compensation following a sudden reduction of continuous positive airway pressure (CPAP) in subjects with and without OSA.
Methods
Ten obese patients with OSA (mean (SD) apnoea‐hypopnoea index 62.6 (12.4) events/h) and 15 healthy non‐obese non‐snorers were instrumented with intramuscular genioglossus electrodes and a mask/pneumotachograph which was connected to a modified CPAP device that could deliver either continuous positive or negative pressure. During stable non‐rapid eye movement sleep the CPAP was repeatedly reduced 2–10 cm H2O below the level required to eliminate flow limitation and was held at this level for 5 min or until arousal from sleep occurred.
Results
During reduced CPAP the increases in genioglossus activity (311.5 (49.4)% of baseline in subjects with OSA and 315.4 (76.2)% of baseline in non‐snorers, p = 0.9) and duty cycle (123.8 (3.9)% of baseline in subjects with OSA and 118.2 (2.8)% of baseline in non‐snorers, p = 0.4) were similar in both groups, yet patients with OSA could restore ventilation without cortical arousal less often than non‐snorers (54.1% vs 65.7% of pressure drops, p = 0.04). When ventilatory recovery did not occur, genioglossus muscle and respiratory timing changes still occurred but these did not yield adequate pharyngeal patency/ventilation.
Conclusions
Compensatory mechanisms (increased genioglossus muscle activity and/or duty cycle) often restore ventilation during sleep but may be less effective in obese patients with OSA than in non‐snorers.
doi:10.1136/thx.2006.070300
PMCID: PMC2094262  PMID: 17412778
21.  A wake up call for sleep disordered breathing 
Conclusions
OSAS is the most common and best-recognized form of SRBD. Effective treatment is available with CPAP being the treatment of choice, once the essential nonspecific measures of excluding endocrine and other treatable causes, including weight loss and avoiding sedative agents have been undertaken. The expense of CPAP apparatus and the need to use this for prolonged period may prompt some patients to evaluate other sub-optimal options. Surgical treatment will continue to be a gamble or a treatment of last resort. Whatever plan is developed, it is important that the patient be reassessed after six months and then by annual PSGs.
The potential population of snorer / apneic patients is so wide and the cost of the proper care so high that the field is ripe for abuses. The confusion between symptoms of snoring and the incidence of SRBD has compounded this proliferation. Cut-rate care that cuts corners is often more expensive in the long run. Interested readers should be aware of the potential inappropriate applications of surgical treatment, especially LAUP, and be alerted to the best medical interests of their patients.
doi:10.1007/BF02996835
PMCID: PMC3451485  PMID: 23119474
22.  Panorametry: suggestion of a method for mandibular measurements on panoramic radiographs 
Head & Face Medicine  2009;5:19.
Background
Orthopantomography (panoramic radiography) has been used for the study of measurements involving particularly the prediction of the eruption of impacted lower third molars and analyses of measurements of the ramus and head of mandible. The discrepancies involved with the projection of this radiographic image has stimulated the search for further ways to use it, particularly in orthodontic treatments and oral and maxillofacial surgeries. The author proposes a graphimetric method for the mandible, based on panoramic radiography. The results are expressed in linear and angular measurements, aiming at bilateral comparisons as well as the determination of the proportion of skeletal and dental structures, individually and among themselves as a whole. The method has been named Panorametry, and allows measurement of the mandible (Mandibular Panorametry) or the posterior mandibular teeth (Dental Panorametry). When combining mandible and maxilla, it should be referred to as Total Panorametry. It may also be used, in the future, with Cone Beam computed tomography (CT) images, and in this case it may be mentioned as CT Panorametry.
doi:10.1186/1746-160X-5-19
PMCID: PMC2777132  PMID: 19852787
23.  Distraction osteogenesis in a severe mandibular deficiency 
Objective
Distraction osteogenesis is an alternative treatment method for the correction of mandibular hypoplasia. In this case report, distraction with a multidirectional extraoral device was performed to gradually lengthen the corpus and ramus of a patient who had a severe hypoplastic mandible.
Materials and methods
The patient underwent bilateral extraoral ramus and corpus distraction osteogenesis. After seven days of latency period, distraction was performed 0.5 mm twice a day. Subsequent consolidation period was 12 weeks.
Results
The patient's mandible was elongated successfully. Cephalometric analysis revealed that ANB angle decreased from 13° to 6°, overjet of 15 mm decreased to 4 mm, corpus length increased from 49 mm to 67 mm, and ramus length increased from 41 mm to 43 mm. Posterior airway space (PAS) also increased due to advancement of the mandible. In stereolithographic model evaluation it was determined that the distances from condylion to gonion and from gonion to pogonion increased.
Conclusion
Satisfactory results from both aesthetic and functional standpoints were obtained by distraction osteogenesis of the ramus and corpus.
doi:10.1186/1746-160X-3-7
PMCID: PMC1797165  PMID: 17239254
24.  Prevalence of short sleep duration and its association with obesity among adolescents 15- to 19-year olds: A cross-sectional study from three major cities in Saudi Arabia 
Annals of Thoracic Medicine  2012;7(3):133-139.
BACKGROUND:
Adequate sleep has been considered important for the adolescent's health and well being. On the other hand, self-imposed sleep curtailment is now recognized as a potentially important and novel risk factor for obesity. The present study aimed to assess the prevalence of short sleep duration and its association with obesity among Saudi adolescents.
METHODS:
This is a school-based cross-sectional study with self-reported sleep questionnaires. It was conducted during the years 2009/2010 in three cities in Saudi Arabia; Al-Khobar, Jeddah, and Riyadh. Participants were 2868 secondary-school males (1379) and females (1389) aged 15 to 19 years, randomly selected using a multistage stratified sampling technique. Measurements included weight, height, waist circumference, BMI, and sleeping duration. Logistic regression analysis while adjusted for age, gender, and location was used to examine the associations between sleep duration and obesity measures.
RESULTS:
The mean (SD) of sleep duration was 7.2 (1.6) hours/day with no significant differences between males and females. About 31% of the participants obtain less than 7 hours of sleep per day, while approximately 50% of the sample gets less than 8 hours of daily sleep. Two-way ANCOVA results while controlling for the effect of age revealed a significant gender by school-type interaction (P<0.001). In addition, adequate sleep duration increased the odds of having normal weight (adjusted odds ratios = 1.28, 95% CI = 1.08-1.50, P = 0.003).
CONCLUSION:
The present study observed a high prevalence of short sleep duration among Saudi adolescents 15- to 19-year olds and that short sleep duration was significantly associated with increased risk of overweight and obesity. Future interventions should investigate whether adopting a healthy lifestyle by adolescents with short sleep duration would improve their sleeping habits or not.
doi:10.4103/1817-1737.98845
PMCID: PMC3425044  PMID: 22924070
Adolescents; obesity; Saudi Arabia; sleep duration; waist circumference
25.  Assessment of bone mineral density in the jaws and its relationship to radiomorphometric indices 
Dentomaxillofacial Radiology  2010;39(5):284-289.
Objectives
The aim of this study was to evaluate maxillary, mandibular and femoral neck bone mineral density using dual energy X-ray absorptiometry (DXA) and to determine any correlation between the bone mineral density of the jaws and panoramic radiomorphometric indices.
Methods
49 edentulous patients (18 males and 31 females) aged between 41 and 78 years (mean age 60.2 ± 11.04) were examined by panoramic radiography. Bone mineral density (BMD) of the jaws and femoral neck was measured with a DXA; bone mineral density was calculated at the anterior, premolar and molar regions of the maxilla and mandible.
Results
The mean maxillary molar BMD (0.45 g cm−2) was significantly greater than the maxillary anterior and premolar BMD (0.31 g cm−2, P < 0.05). Furthermore, the mean mandibular anterior and premolar BMD (1.39 g cm−2 and 1.28 g cm−2, respectively) was significantly greater than the mean mandibular molar BMD (1.09 g cm−2, P < 0.01). Although BMD in the maxillary anterior and premolar regions were correlated, BMD in all the mandibular regions were highly correlated. Maxillary and mandibular BMD were not correlated with femoral BMD. In addition, mandibular cortical index (MCI) classification, mental index (MI) or panoramic mandibular index (PMI) values were not significantly correlated with the maxillary and mandibular BMDs (P > 0.05).
Conclusions
The BMD in this study was highest in the mandibular anterior region and lowest in the maxillary anterior and premolar regions. The BMD of the jaws was not correlated with either femoral BMD or panoramic radiomorphometric indices.
doi:10.1259/dmfr/20522657
PMCID: PMC3520251  PMID: 20587652
bone mineral density; dual energy X-ray absorptiometry; maxilla; mandible

Results 1-25 (329575)