OBJECTIVE: To investigate the prevalence of throat disease in secondary school teachers of Urumqi. METHOD: Use Stage-Two random sampling at 11689 teachers from 109 secondary schools in Urumqi; Draw 3 217 from 11689 teachers in 109 secondary schools to accept voice self-assessment questionnaire survey and routine examination of throat, and the one who were confirmed abnormal in routine inspection would be underway stroboscopic laryngoscopy. RESULT: The total illness prevalence rate of throat disease in secondary school teachers of Urumqi is 28.23%; there is no statistic difference of illness prevalence rate between male and female teachers (P > 0.05). However, results showed statistical significance of illness prevalence rate in teachers of different racial-groups with different years of teaching experience (P < 0.05). Teachers who have 5 to 15 years of teaching experience suffer a high incidence of throat diseases. Among eight racial groups involved in investigation, Kazak teachers are in the highest illness prevalence rate. The results of assessment for voice disorder index between teachers with and without throat diseases showed statistical difference in total score TVH (P < 0.05), which is shown significant in the physical and emotional areas (P < 0.05), while there is no statistical difference in function. Diseases of pharyngeal portion are mainly chronic pharyngitis and hyperplastic tonsil in tongue root; Diseases of laryngeal portion are mainly chronic laryngitis and vocal nodule for female, while mainly chronic laryngitis and vocal polypus for male. CONCLUSION There is no significant difference in illness prevalence rate of throat disease for secondary school teachers in Urumqi between genders; the highest prevalence rate is in teachers who have 5 to 15 years teaching experience; among different racial groups, Kazak teachers are of the highest illness prevalence rate; the illness prevalence of throat diseases is related with voice disorder index.
Adult ; China ; epidemiology ; Faculty ; Female ; Humans ; Laryngeal Diseases ; epidemiology ; Male ; Middle Aged ; Occupational Diseases ; epidemiology ; Pharyngeal Diseases ; epidemiology ; Prevalence ; Surveys and Questionnaires ; Voice Disorders ; epidemiology ; Voice Quality ; Young Adult

Objective : To study the anatomical characteristics of the root and root canal system of the mandibular second permanent molar in the Uygur people and provide a reference for clinical practice. Methods : A total of 125 mandibular second permanent molars were extracted from Uygur patients in hospitals in the Xinjiang Uygur Autonomous Region. Three-dimensional reconstruction was performed after micro-CT scanning. The number of root canals, the root canal type (Weine classification and Fan′s C-shaped canal classification) and the occurrence of lateral accessory canals were observed. Results : A sex difference was not detected in the root number or root form (χ2 = 1.277, P = 0.259). The incidence of 2-rooted molars was 70.4% (n = 88); type 2-1 canals were most common in the mesial root, with an incidence of 29.5%, followed by type 1-1 and 2-2 canals (each with an incidence of 26.1%), and the distal root mostly had a type 1-1 canal (96.6%). The incidence of single-rooted molars was 28.8%, and the frequency of C-shaped (n = 28) and non-C-shaped (n = 8) single-rooted molars was 22.4% and 6.4%, respectively. A three-rooted molar was detected in one case. The incidence of accessory canals was 65.2%. Conclusion Uygur mandibular second molars are mainly composed of two roots, and the incidence of a single root and root canal fusion is low (including C-shaped canals). Two-rooted molars frequently have two mesial canals and one distal canal.