Comparison of dimensional accuracy of elastomeric impression materials using 3D laser scanner.

Background: The dimensional accuracy of elastomeric impression materials has been evaluated by different methods but their reliability is still questionable. The aim of this study was to evaluate the dimensional accuracy of elastomeric impression material using 3D laser scanner. Method: In the present study, a metal die with its custom tray were designed. Using this die and tray, 10 impressions each were made from addition silicone (Aquasil LV; Dentsply), condensation silicone (Speedex coltene, Whaledent) and polyether (3M; ESPE). All the impressions were poured with Type IV die stone and total of 30 die replicas were obtained. These were scanned with a Picza 3D laser scanner (LPX 600, Roland,California) and the difference between the stone model was calculated by determining its volumetric changes using CAD-CAM pero version 2.0. One way analysis of variance (ANOVA) was used to compare the groups, whereas significance of mean difference between the groups was done by Tukey HSD. Results: All the three groups showed mean decrease indicating a dimensional shrinkage from the master die. Mean percentage dimensional change in condensation silicone was maximum (-319.02 ±15.50) followed by polyether (-122.59 ± 0.64) and least in addition silicone (-23.83 ± 0.43). All the results were statistically significant (p<0.001). Conclusion: Picza 3D laser scanner can precisely measure the volumetric changes in all the three elastomeric impression materials.

Reliability of STOP-Bang questionnaire and pulse oximetry as predictors of OSA - a retrospective study.

OBJECTIVE: To verify the reliability of a STOP-Bang questionnaire and objective blood oxygen concentration (SpO2) estimation by pulse oximetry as an indicator of patients' vulnerability to OSA, by correlating data of these two tests with that of the "gold standard" all-night polysomnography. METHODS: STOP-Bang score and pulse oximetry value (SpO2) for each patient were tabulated against the total sleep AHI score (obtained from subsequent all-night polysomnography) and analyzed to evaluate the diagnostic accuracy of the STOP-Bang questionnaire and pulse oximetry. RESULTS: With sensitivity and specificity scores of 91.2% and 88.6%, respectively, positive predictive value 90.5%, negative predictive value 40.2%, the twin diagnostic test (STOP-Bang and pulse oximetry) was found to be highly congruent with the polysomnography (PSG), achieving a diagnostic accuracy of 85%. CONCLUSION: Dental chairside screening by STOP-Bang questionnaire and pulse oximetry would be a good option, especially where logistic and economic constraints impede all-night polysomnography.

Correlation between duration of edentulism and severity of obstructive sleep apnea in elderly edentulous patients.

Objectives: To investigate the correlation between duration of edentulism and severity of obstructive sleep apnea in elderly edentulous patients. Material and Methods: 1,017 patients aged 55-65 years, with a history of edentulism of 12-60 months were screened. Detailed history of tooth loss and period of edentulism was recorded for the 414 patients who tested positive for OSA (obstructive sleep apnea). Complete dentures were prepared for each patient and they were trained to use the dentures as a mandibular advancement device (MAD) during sleep at night. Apnea-hypopnea index (AHI) data at pre-treatment, six months and one-year post-treatment time intervals was recorded. A correlation between the period of untreated edentulism and severity of OSA and improvement post-treatment was derived in this study. Results: Mean duration of edentulism was 12.14±2.57 months and mean AHI was 16.62±13.24. For every three month increase in the duration of edentulism (after initial 6 months of total tooth loss), there was a statistically significant increase in severity of OSA. Patients who are edentulous for more than 15 months are increasingly vulnerable to OSA. Discussion: Severity of OSA in afflicted long-term edentulous patients was in direct relation to the period of untreated edentulism and regressed likewise with concomitant denture wear and mandibular advancement during sleep at night. Early prosthetic rehabilitation of edentulous patients is imperative to obviate morbidity of OSA.

Customized wire prosthesis (Devise) for alar collapse in sleep apnoea.

BACKGROUND: Alar collapse is known to aggravate snoring-severity and possibly the severity of obstructive sleep apnoea. Various surgical techniques, implants and commercial mechanical/prosthetic nasal alar dilators are evident in literature. MATERIAL AND METHODS: A malleable wire prosthesis at 'no' manufacturing cost is custom designed through computer modelling and animation and thereafter tested for its efficacy in 20 normal subjects as per visual analog scale along with its correlation with patient-profiles. OBSERVATIONS AND RESULTS: All subjects reported improvement in their nasal patency ranging from 30% to 99% but no correlation was seen between the degree of improvement & patient variables. This improvement in normal subjects indicates even a better improvement in true alar collapse. CONCLUSION: Main advantages of this devise is its extremely low-cost, non-traumatic nature, adjustability to suit patient comfort and can be customised across all types of noses. However it seems cosmetically unacceptable during the daytime, as well as for small children. With no correlation with patient factors the acceptability of this devise is mainly dependent on a good customized design. With a constant use during bedtime in alar collapse this device may not only resolve snoring and improve the sleep-quality of spouse but also enhances oxygenation during sleep.

Host-Parasite Interaction in Sarcoptes scabiei Infestation in Porcine Model with a Preliminary Note on Its Genetic Lineage from India.

The burrowing mite Sarcoptes scabiei causes scabies in humans or mange in animals. It infests a wide range of mammalian species including livestock, companion animals, wild animals, and humans. Differential diagnosis of Sarcoptes varieties is key for epidemiological studies and for formulation of an eradication program. Host-parasite interaction at the systemic level is very important to understand the pathogenicity of the mite. This communication deals with the preliminary report on the genetic characterization of S. scabiei from India. Moreover, the effect of S. scabiei infestation on host physiology with special emphasis on serum biochemical parameters, lipid profile, oxidant/antioxidant balance, stress parameters, and immune responses were evaluated in a porcine model. Cytochrome C oxidase 1 and voltage-sensitive sodium channel based phylogenetic study could distinguish human and animals isolates but could not distinguish host or geographical specific isolates belonging to animal origin. An absence of host-specific cluster among animal isolates argues against the hypothesis of delineating S. scabiei as per host origin. Elevated levels of markers of liver function such as albumin, AST, ALT, ALP, and LDH in infested animals indicated impaired liver function in infested animals. S. scabiei infestation induced atherogenic dyslipidemia indicated by elevated levels of total cholesterol, low-density lipoprotein cholesterol and triglycerides, and a decreased level of high-density lipoprotein cholesterol. Oxidative stress in infested animals was indicated by a high level of nitric oxide and serum MDA as oxidative stress markers and low antioxidant capacity. S. scabiei triggered stress response and elevated levels of serum cortisol and heat shock proteins were recorded in infested animals. S. scabiei infestation increased the serum concentration of immunoglobulins and was associated with up-regulation of IL-2, IFN-γ, IL-1ß, and IL-4 indicating both Th1 and Th2 response. The results of the study will be helpful for a better understanding of host-parasite interaction at the systemic level in crusted scabies in pigs.

A comparative study of masticatory performance in complete denture patients before and after application of soft liner.

BACKGROUND: To compare the masticatory performance in complete denture patients before and after application of soft liner and to assess the effect of aging of soft liner on masticatory performance at different intervals of time. METHODS: A total of 30 complete denture wearers between age of 64 and 80 years, were selected from both the sex (20 men, 10 women). This study evaluated the effect of before and after application of chair-side soft liner on masticatory performance of complete denture wearers by using raw carrots and roasted peanut as the test food. This study further evaluated the cushioning effect of chair-side soft liner material at the interval period of 1week, 4 weeks, 8 weeks, 12 weeks and 16 weeks. RESULTS: There were significant differences in masticatory performance without soft liner as compared to with soft liner at different intervals of time. The performance was found to be significantly higher for raw carrot as compared to roasted peanut (p < 0.001). For both the materials peak performance was recorded at 4th week. CONCLUSION: The use of soft liner helps in increasing the masticatory performance among complete denture wearers.

Incidence of Obstructive Sleep Apnea in Elderly Edentulous Patients and the Possible Correlation of Serum Serotonin and Apnea-Hypopnea Index.

PURPOSE: To estimate the incidence of obstructive sleep apnea (OSA) in elderly edentulous patients (aged 60-65 years) and investigate a correlation of serum serotonin levels with the apnea-hypopnea index (AHI), respiratory effort-related arousal (RERA), and respiratory disturbance index (RDI). MATERIALS AND METHODS: 381 elderly completely edentulous patients (307 male, 74 female) aged 60 to 65 years with a history of edentulism of 12 to 15 months, seeking oral rehabilitation at the prosthodontic clinic at Saraswati Dental College & Hospital, Lucknow, India, between January 2014 and January 2016 were enrolled for the present study. After application of the inclusion and exclusion criteria of this study, 183 patients (162 male, 21 female) who were found susceptible, were subjected to the BERLIN questionnaire and Epworth Sleepiness Scale (ESS) to assess sleep disordered breathing (SDB) and then put through all-night polysomnography (PSG). On the basis of AHI, RERA, and RDI scores, 156 patients (143 male, 13 female) who tested positive for OSA were classified according to its intensity. All 156 patients underwent body-mass index (BMI) estimation, cephalometry, and intraoral examination for skeletal and soft tissue profile record. Serum serotonin was estimated from whole blood samples for the 156 OSA and the 27 normal patients. The 156 (147 nonobese, 9 obese) OSA-positive patients were provided with complete dentures and were trained to use the same as a modified mandibular advancement device (MAD) during sleep at night. These patients were kept on a quarterly follow-up for 9 months. Data collected was subjected to statistical analysis, and inferences drawn. RESULTS: The incidence of OSA in elderly edentulous subjects was found to be 32.03% in males and 8.91% in females. A mere 9 out of 156 (5.76%) elderly edentulous OSA patients were found to be obese (Class I) on the basis of BMI estimation. Cephalometry of the patients showed that they had a skeletal class I maxillomandibular relationship. AHI scores of nonobese patients revealed that most of the patients had moderate OSA, followed by mild OSA and severe OSA. Serum serotonin levels ranged from 53 to 83 ng/dL. AHI score of the 9 obese patients were in the moderate to severe range, and their serum serotonin levels were 60 to 70 ng/dL. A correlation between severity of OSA and serum serotonin level was validated in this study. CONCLUSION: OSA was found to be prevalent in edentulous subjects due to pharyngeal collapse and decreased neuromuscular control. An inverse relationship of serum serotonin levels and AHI scores was established.

Obstructive Sleep Apnea and Neurocognitive Dysfunction in Edentulous Patients.

PURPOSE: To record the incidence of cognitive dysfunction in edentulous patients suffering from obstructive sleep apnea (OSA) and establish a plausible hypothesis to explain the correlation of cognitive dysfunction and OSA. MATERIALS AND METHODS: In this study, 315 edentulous patients (aged 60 to 65 years) visiting the outpatient department at Saraswati Dental College, Lucknow were recruited from January 2013 to October 2015. Prosthodontic Diagnostic Index (PDI) classification was used to assess the intraoral condition to relate it with the span of edentulousness. The BERLIN questionnaire and Epworth Sleepiness Scales were used to diagnose sleep-disordered breathing, following which the patients were put through all-night polysomnography. The apnea-hypopnea index (AHI) scores were derived. Mild and moderate OSA patients were classified into mild, moderate, and severe cognitive dysfunction based on SGRQ-C and SCD. Data were tabulated according to a new classification (Cognitive Dysfunction of Dental Sleep Medicine Patients [CDDSMP] Classification) designed specifically for this study. Data were analyzed using SPSS v15.0. Scores were tabulated as mean ± SD and median [IQR] values. Change from baseline was analyzed using Wilcoxon signed rank test. RESULTS: Mean scores at different time intervals were 3.03 ± 1.76 (3 months), 2.98 ± 1.80 (6 months), and 2.81 ± 1.84 (9 months). The median [IQR] values of scores at all time intervals except 9 months were 3 [1 to 5]. At 9 months, median [IQR] was 2 [1 to 5]. A significant change in scores was observed in the 3-month interval (p ≤ 0.001). CONCLUSIONS: The severity of OSA and neurocognitive dysfunction could be directly related to the PDI classification and the span of edentulousness of the patient and modified mandibular advancement device treatment significantly improved the patients' condition, which was reflective from 3 months post-intervention itself.

Effect of mucostatic and selective pressure impression techniques on residual ridge resorption in individuals with different bone mineral densities: A prospective clinical pilot study.

STATEMENT OF PROBLEM: Although different impression techniques have been advocated for complete denture prosthodontics, objective studies that predict their effect on alveolar bone resorption are lacking. PURPOSE: The purpose of this prospective clinical pilot study was to objectively evaluate the effect of complete dentures fabricated by different impression techniques on mandibular residual ridge resorption in individuals with different bone mineral density. MATERIAL AND METHODS: Ninety-six participants with edentulism, selected according to inclusion criteria, underwent bone mineral density assessment and were divided into normal, osteopenic, and osteoporotic groups. Half of the participants in each group were provided with dentures fabricated by selective pressure impression technique (subgroup SIT), and the other half were provided with dentures fabricated by mucostatic impression technique (subgroup MIT). Computed tomographic scans of the mandible were made at denture delivery and 1 year after prosthesis use to assess alveolar bone height and width difference at marked locations at and after denture delivery. The data obtained were analyzed with the Student t test (α=.05). RESULTS: Significantly less reduction in mandibular ridge height and width was found in the MIT versus the SIT subgroups in both osteopenic and osteoporotic participants (P<.05). No significant subgroup difference was found for normal bone mineral density group, although resorption increased in height and width for the SIT subgroup. CONCLUSIONS: Mandibular residual ridge resorption was reduced for dentures fabricated using the mucostatic impression technique compared with the selective pressure impression technique in individuals with diminished bone density.

Interaction of arsenic(III) and arsenic(V) on manganese dioxide: XPS and electrochemical investigations.

Manganese dioxide (MnO2) synthesized by solid-state reaction was characterized and sorption of As(III) and As(V) on it was studied in batch mode using 76As radiotracer. Arsenic removal efficiency was ∼98 % in the pH range of 3-9. Solvent extraction study indicated that >95% of arsenic is present as As(V) after sorption. A new electrochemical method was developed for explaining the arsenic-manganese interactions. Cyclic voltammetry and chronopotentiometry measurements were carried out which indicated the difference in the interaction of As(III) and As(V) with MnO2. X-ray Photoelectron Spectroscopy (XPS) was carried out in which the 3p3/2 binding energy peak of As(III) and As(V) standards was compared with the binding energy peaks observed for arsenic sorbed on manganese dioxide. The binding energy peaks of arsenic on MnO2 were matching with that of As(V), irrespective of the oxidation state of arsenic taken for sorption. The study confirmed that irrespective of the initial oxidation state, arsenic was sorbed on MnO2 as As(V); during the oxidation of As(III) by MnO2, manganese was reduced to Mn(II) and the Mn(II) formed during sorption was sorbed on the surface creating fresh surface promoting further sorption. Based on the observations, a mechanism of sorption has been proposed.

An innovative approach to the prosthodontic management of Class III mandibular defect.

Class III mandibular resection due to surgical treatment of jaw tumor produces a discontinuity in the mandible which is severely incapacitating to the patient. It leads to a deviation and rotation of the mandible which depends on the amount of tissues resected the manner of surgical site closure, loss of proprioceptive sense of occlusion, the presence, and condition of teeth, and the time of initiation of prosthodontic therapy. These put together makes the task of prosthodontic rehabilitation quite arduous. Guide flange prosthesis is a comparatively simple and cost-effective method of restoring the esthetics and function to an acceptable level. This clinical report describes an innovative and simplified approach to impression making (sectional two-step impression) to minimize trauma to the underlying and circumoral fragile tissues postsurgery, and to the fabrication of buccal guide flange (wrought wire supported and reinforced guide flange) for prosthetic rehabilitation of a patient with Class III mandibular resection.

Effect of Different Firing Temperatures on Structural Changes in Porcelain.

PURPOSE: To study the structural changes occurring in the dental porcelain mass fired at various firing temperatures using scanning electron microscopy (SEM) and X-ray diffraction (XRD) spectroscopy. Also, additional tests, namely compressive strength, abrasion resistance analysis, and the amount of oxides released, were conducted at different firing temperatures. MATERIALS AND METHODS: Six groups (40 specimens in each group) of porcelain mass were prepared. The dimensions and weight of all the specimens were kept constant. The specimens were then heat treated at different firing temperatures (660°C, 760°C, 860°C, 900°C, 960°C, 990°C). Half of the specimens of each group were subjected to a compressive strength test on a universal testing machine and then finely ground using an electrochemical grinder to prepare for XRD analysis. The other half of the specimens was weighed to analyze the amount of oxides released after each firing cycle. Following this, the specimens underwent an abrasion resistance test on a Nanovea Tribometer. The unaltered surface was scanned using SEM. The data (numerical and graphical) for all the tests were recorded and analyzed using one-way ANOVA and post hoc Tukey test. RESULTS: The specimens fired at 900°C exhibited superior compressive strength and abrasion resistance. The quantity of oxides released by the specimens fired at 900°C was the least compared to specimens heat treated at the other firing temperatures. XRD analysis proved that the oxide released by the porcelain mass was calcium aluminum chromium oxide. Also, the fewer peaks obtained in the XRD graphs of specimens fired at 900°C signified lesser porosities in the porcelain specimens. SEM analysis depicted a homogeneous mass of porcelain at 900°C. CONCLUSION: All the above findings validate the objective of studying the physical and internal structural changes of dental porcelain when subjected to an increasing firing temperature gradient. The specimens fired at 900°C exhibited superior strength and abrasion resistance. SEM analysis depicted a homogeneous mass of dental porcelain, implying that firing was complete at 900°C.

Effect of Firing Temperature at the Porcelain-Metal Alloy Interface in Porcelain-Fused-to-Metal Restorations. A SEM/EDS Study.

PURPOSE: To probe in greater detail the changes at the ceramometal interface induced by heat energy absorption, using energy diffraction X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) and correlate these changes with the shear bond strength of porcelain to nickel chromium alloy. MATERIALS AND METHODS: Seventy-five strips of nickel-chromium alloy (20 mm long, 5 mm wide, 3 mm thick) were prepared and layered with porcelain, conforming to ANSI/ADA specification no. 38 (for Metal-Ceramic Dental Restorative Systems: 2010). These test specimens were divided equally into three groups. Specimens of each group (25) were fired to a specific temperature range, that is 700°C, 900°C, and 960°C. SEM and EDS were performed on all specimens, at the metal alloy/ceramic interface. Bonding of the ceramic layer to the metal alloy was evaluated by a shear bond strength test as per ANSI/ADA specification no. 38. The data were recorded and analyzed using one-way ANOVA and post hoc Tukey HSD test. RESULTS: SEM images of the porcelain/metal alloy interface revealed roughness of the metal alloy surface adjacent to the ceramic layer. EDS study revealed that an oxygen depletion zone was formed at the interface region, facilitating the formation of intermetallic compounds. The mean shear bond strength showed an upward trend until 900°C and decreased thereafter. CONCLUSION: Formation of intermetallic compounds at the interface, in the presence of an oxygen depletion zone, was the prime factor in bonding of porcelain to metal alloy. This provides a new concept of ceramometal bonding.

Lifestyle and Occupational Stress: A Potential Risk Factor for Obstructive Sleep Apnea in Nonobese Male Subjects.

PURPOSE: To record the incidence of obstructive sleep apnea (OSA) in nonobese male subjects and investigate the coexistence of lifestyle stress, sleep deprivation, and upper airway inflammation. MATERIALS AND METHODS: 552 patients were assessed during a survey of banks, government and corporate offices, recruitment agencies, and schools between January 2012 and January 2016. After applying the inclusion and exclusion criteria designed for this study, the number of patients tapered down to 120 patients who underwent diagnostic tests, viz. polysomnography, chemiluminiscence immunoassay, nephelometry, and upper airway endoscopy. This revealed the presence of OSA coexistent with elevated serum cortisol, C-reactive protein (CRP), and upper airway inflammation. RESULTS: Polysomnography showed that 57 of 120 patients suffered from OSA. Objective evaluation of these patients exposed an undercurrent of lifestyle stress in 39 patients. CRP and serum cortisol were found to be significantly high (1.60 ± 0.52 and 7.20 ± 0.76 µg/dL, respectively) in 30 patients. Endoscopy revealed 18 patients with moderate, 7 with severe, and 5 with no upper airway inflammation. CONCLUSION: The results of this study demonstrated that OSA was found to be prevalent in the cohort of nonobese male patients studied. Coexistence of lifestyle stress, sleep deprivation, and upper airway inflammation was revealed.

The long-term effects of mandibular advancement splint on cardiovascular fitness and psychomotor performance in patients with mild to moderate obstructive sleep apnea: a prospective study.

BACKGROUND: Obstructive sleep apnea (OSA) manifests as a reduction or complete cessation of airflow despite an ongoing inspiratory effort, leading to hypoxemia and hypercapnia. The inability to maintain normal breathing reduces the oxygen saturation in blood leading to a cycle of various systemic implications. Hence, a prospective single arm study was planned to evaluate the long-term (2 years) effect of oral appliance on cardiovascular fitness and psychomotor performance in patients with mild to moderate obstructive sleep apnea. METHODS: Thirty dentulous OSA patients (25 males; 5 females; age 41 ± 4 years; BMI 22 ± 5; AHI 5-30) were included in the study. All the patients were assessed for systolic blood pressure (SBP), diastolic blood pressure (DBP), apnea/hypopnea index (AHI), lipid peroxidation, and psychomotor vigilance test at baseline, 6 months, 1 year, and 2 years after wearing mandibular advancement splint (MAS). RESULTS: A significant reduction in AHI, blood pressure, and lipid peroxidation was observed following MAS use. Psychomotor vigilance test showed marked improvement in response time with almost 0 count of lapses after 2 years of MAS use. CONCLUSIONS: The present study suggested that MAS can be helpful in improving cardiovascular fitness and cognitive response in patients with mild to moderate OSA.

Effect of Different Ferrule Length on Fracture Resistance of Endodontically Treated Teeth: An In vitro Study.

INTRODUCTION: A ferrule has been described as a key element of tooth preparation when using a post and a core. It is a vertical band of tooth structure at the gingival aspect of crown preparation. It lessens the stress transmission to the root which is due to forces from posts or bending during seating of the post. The incorporation of a ferrule can help to withstand the forces of occlusion, preserve the hermetic seal of the luting cement, and minimize the concentration of stresses at the junction of post and core. AIM: To evaluate and compare the effect of ferrule length on fracture resistance of endodontically treated mandibular premolar teeth, restored with prefabricated glass fiber post luted with resin cement, composite core and a full coverage metal crown. MATERIALS AND METHODS: Forty freshly extracted mandibular premolars were treated endodontically. They were randomly divided into four groups according to their ferrule height: 3 mm, 2 mm, 1 mm and 0 mm (no ferrule). All specimens were restored with prefabricated glass fibre posts (Reforpost, Angelus) and composite resin (Filtek™ Z250XT). Standardized preparation was done on each specimen to receive a cast metal crown. The specimens were thermocycled and compressive static load at a crosshead speed of 1 mm/min was applied at an angle of 30° on lingual incline of buccal cusp of the crown until failure occurred. The load (N) at failure and mode of failure were recorded. Statistical analysis was performed with Kruskal Wallis test. RESULT: Fracture resistance values among the groups was found to be statistically significant (p<0.001). The 3 mm ferrule group had significantly higher failure load (971.99±133.07) compared to 2 mm (848.84±109.60), 1 mm (714.64±133.89) and 0 mm ferrule groups (529.36±119.95). More favourable failure modes were observed in almost all groups. CONCLUSION: The results of this study showed that fracture resistance of endodontically treated teeth increases as ferrule length increases.

A study to evaluate the effect of different mandibular horizontal and vertical jaw positions on sleep parameters in patients with obstructive sleep apnea.

OBJECTIVE: The worldwide prevalence of obstructive sleep apnea (OSA) is increasing day by day and is estimated to be as prevalent as asthma and diabetes. Untreated sleep apnea can have dire health consequences and can increase risk of hypertension, diabetes, heart disease, and heart failure. Dentists are often the first professional to become aware of a potential problem since they are usually in contact with their patients more frequently than are physicians. The present study was aimed at evaluating the effect of four different mandibular advancement splints fabricated at different jaw positions on sleep parameters in patients with OSA. METHOD AND MATERIALS: 72 patients who fulfilled the study criteria were selected. All the patients were randomly divided into four groups of 18 patients each. All the patients in group 1 were given a mandibular advancement splint (MAS) fabricated at 60% of maximum protrusion and 4 mm of vertical opening. All the patients in group 2 were given a MAS fabricated at 60% of maximum protrusion and 6 mm of vertical opening. All the patients in group 3 were given a MAS fabricated at 70% of maximum protrusion and 4 mm of vertical opening. All the patients in group 4 were given a MAS fabricated at 70% of maximum protrusion and 6 mm of vertical opening. RESULTS: The maximum change in all the sleep parameters was observed in group 3 when MAS was fabricated at 70% of maximum protrusion and 4 mm of vertical opening. CONCLUSION: The present study suggested that MAS was more effective with no patient discomfort when fabricated at 70% of maximum protrusion and 4 mm of vertical jaw separation.

Changes in Upper Airway Volume in Edentulous Obstructive Sleep Apnea Patients Treated with Modified Mandibular Advancement Device.

PURPOSE: This study was an attempt to verify the utility of complete dentures modified as a mandibular advancement device (MAD) in effecting expansion in pharyngeal volume to treat obstructive sleep apnea (OSA) in edentulous patients. MATERIALS AND METHODS: The sample consisted of 17 patients (12 male, 5 female, average age 61 ± 4 years; BMI, 22 ± 5; apnea hypopnea index [AHI] 15 to 30). All patients had worn complete dentures for at least 1 year; all patients had the dentures modified to a MAD. Five variables were assessed preoperatively and 6 months after wearing the modified MADs. These variables were: sleep efficiency, AHI, oxygen desaturation events/hr., mean oxygen saturation, snoring index, and airway volume. This assessment was done by subjecting the patients to all-night polysomnography. RESULTS: Without any prosthesis or device in the edentulous patients, the mean velopharyngeal volume was 8.05 ± 0.58 cm(3) , oropharyngeal volume was 2.14 ± 0.38 cm(3) , and hypopharyngeal volume was 3.26 ± 0.78 cm(3) . With complete dentures (unaltered) in the edentulous patients, the mean velopharyngeal, oropharyngeal, and hypopharyngeal volumes were 10.73 ± 0.98 cm(3) , 2.60 ± 0.48 cm(3) , and 4.31 ± 0.89 cm(3) , respectively. There was a statistically significant change in the airway volume following insertion of the complete dentures modified as MADs with velopharyngeal, oropharyngeal, and hypopharyngeal volume recorded as 11.76 ± 1.07 cm(3) , 3.33 ± 0.51 cm(3) , and 4.94 ± 0.83 cm(3) , respectively. CONCLUSION: From the results obtained in this limited small sample study, it was inferred that the pharyngeal expansion induced by complete dentures modified as MADs effectively reduced symptoms of OSA. Increased volume was most pronounced in the velopharynx region followed by hypopharynx and oropharynx.