Aim: The aim of the study was to evaluate the anatomical and structural changes in the upper airway in cases of obstructive sleep apnoea and to evaluate the efficacy of the various modalities available in diagnosing the site of obstruction in case of obstructive sleep apnoea.  

Study design: Prospective analysis                                                Patients: 60 adults patients Patients who were diagnosed as cases of obstructive sleep apnea on the basis of nocturnal polysomnography and has not undergone any surgical operation for obstructive sleep apnea were included in study.                            Methodology: All patients were subjected to detailed history taking and clinical examination. Majority of the patients that is 48 (80%) in our study were males whose mean age was 49.1 years. There were 12 females (20%) whose mean age was 57.5 years. The mean age of the study population was 50.8 years. The patients then underwent Nasopharyngolaryngoscopy, Cephalometry, Non Contrast Computed Tomography and Videofluroscopy.                

Result: In our Study out of the 60 patients who underwent Nasopharyngolaryngoscopy (fiberoptic), 10 Patients (16.7%) had complete obstruction at nasopharynx level. 58 (96.7%) patients had complete obstruction at oropharyngeal level one patient had only 80-90% obstruction.  Whereas all of the 60 patients (100%) had complete obstruction at  hypopharyngeal level. Cephalometry could detect abnormality in 42 out of 60 patients i.e 70% cases in our study. Videofluroscopy showed significant change in length of softpalate in inspiration and expiration amounting to collapse of Nasopharynx, Oropharynx and Hypopharynx in all the patients (Mean% change is 12.55  and SD is 3.23 p< 0.001 ). Non Contrast Computed Tomography inferred that 56 patients (93.3%) had decreased cross sectional area at any part of pharynx (either nasopharynx or oropharynx or hypopharynx ). 

Conclusion: Nasopharyngolaryngoscopy and Videofluruoscopy are very useful in studying the dynamics of upper airway and depicting the changes that occur during apneic events. Cephalometry and Static Computed Tomography are able to assess anatomic abnormalities in the upper airway but efficacy of detection is less as compared to Nasopharyngolaryngoscopy and Videofluroscopy.