ABSTRACT
Introduction: Obesity causes reduction of Lung compliance leading to decrease in lung volumes producing mostly a restrictive type of ventilatory defect. Compression of the thoracic cage by excessive fat and increased pooling of blood in pulmonary vasculature mainly contribute towards a reduction in respiratory compliance. Deposition of fat in diaphragm causes mechanical obstruction to the descent of diaphragm thereby causing increased work of breathing and metabolic demand thereby producing breathing difficulty. The aim of the study: To measure the association of body mass index (BMI) to lung volumes assessed by a digital spirometer. Materials and methods: Apparently healthy individuals above the age group of 15 years attending Master Health Check-up OP and attenders of in-patients of wards of general medicine department, Govt. Chengalpattu Medical College, Chengalpattu of either gender were recruited. Height and weight were measured and BMI was calculated as kg/m2 . Subjects were categorized as normal (BMI=18.5 to 24.9 kg/m2 ); overweight (BMI=25 to 29.9 kg/m2 ); obese Class 1 (BMI=30 to 34.9 kg/m2 ) and obese class 2 (BMI=35 to 39.9) on the basis of BMI. Lung volumes were measured by digital spirometer and were reported as a percentage of predicted values for forced vital capacity (FVC%), forced Vasanthakumar M, Gnanaprakasam J. A cross-sectional analytical study on the association of body mass index to dynamic lung volumes – assessed by digital spirometer in a tertiary care hospital in Chennai. IAIM, 2018; 5(5): 121-128. Page 122 expiratory volume in the first second (FEV1%) and the ratio of FEV1 to FVC (FEV1: FVC). Groups were compared using t-test and ANOVA, the correlation was assessed by Pearson's 'r'. Results: Significant differences in lung volumes were found in different BMI categories. Obese subjects had significantly lower FVC% and the significant difference calculated by using One Way ANOVA F = 11.9 with p = 0.0001. Similarly, obese participants have significantly lower values of FEV1% when compared to participants of normal BMI. The significant difference calculated by using One Way ANOVA F = 6.46 with p = 0.0001. Gender and age had no significant effect on mean values of PFTs. Conclusion: Obese individuals in this sample had a significant decline in lung volumes. The presence of nutritional abundance and a sedentary lifestyle, and importantly influenced by genetic endowment, this system increases adipose energy stores and obesity develops which produces adverse health consequences.
ABSTRACT
Background: Reduction of upper airway (UA) dimensions during sleep is contemplated to cause reduced sleep efficiency (SE) but a definitive association is not affirmed. Efficacy of nasopharyngeal appliance (NPA) in management of UA resistance syndrome (UARS) has not been compared with mandibular repositioning splint (MRS). This study intended to assess relation of UA dimensions to SE and effectiveness of NPA. Materials and Methods: Research had two phases: Case–control study to determine association between UA and SE; randomized control trial (with independent concurrent trial groups and double‑blind design) to analyze treatment outcome with NPA. Subjects were categorized to three groups of 20 in each: A control group of healthy subjects (Group A); two “Randomly Assigned” sample groups of subjects with reduced SE (Groups B and C). Preliminary questionnaire for sleep analysis, Final data collection sheet (first and second case sheets) were recorded, cephalometric variables analyzed, and diagnostic overnight polysomnography was done to match and confirm selection criteria. Three‑dimensional computed tomography was done to analyze airway dimensions before and after appliance placement. ANOVA and post‑hoc tests were used for statistical analysis of results. Conclusions: Reduced UA dimension during sleep is associated with reduced SE; NPA gives better improvement for UARS than MRS.
ABSTRACT
Context: Implant design influences the stress distribution in an implant-supported distal cantilever fixed partial denture and supporting bone tissue. Aim: The purpose of this study was to investigate the effect of implant design on the stress distribution in the framework, implant, and surrounding bone, using a three-dimensional finite-element analysis. Materials and Methods: A three-dimensional finite-element model of a mandibular section of bone with implants placed in the first and second premolar region was created to support a distal cantilever fixed partial denture. A one-piece and two-piece implant and its suprastructure were simulated into wire frame models using Pro engineer (Pro E) program. Four models were created in this study. Results: Comparative analysis of all models showed that the maximum stress overall was in the cervical portion of the secondary abutment. When used in combination, the maximum stress was when the two-piece implant was used as secondary abutment. The one-piece implant showed less stress compared to its counterpart when used as secondary abutment. The maximum stress distribution in the bone was around the neck region of the secondary implant. Conclusion: Within the limitations of this study, it can be concluded that stress distribution is better in a one-piece implant design when compared with the two-piece implant design, with stress concentration being more at the junction of the abutment and the implant fixture in the two-piece implant. When implants are used as abutments (either primary or secondary), irrespective of their position and design, the secondary implant shows the maximum amount of stresses.