Objective To retrospectively analyze the distribution and differences of oral behavior among patients with acute and chro-nic painassociated with temporomandibular disorders(TMD).Methods A total of 212 patients with pain TMD in West China Hospital of Stomatology completed oral behaviors checklist(OBC).SPSS statistical software was used to analyze all the data.Results The pa-tients with pain-related TMD had specific oral behaviors,such as"pressure on the jaw during sleep"(49.5%),"unilateral chewing"(49.5%),"upper and lower teeth contact when not eating"(37.7%),etc.Scores of"upper and lower teeth contact when not eating"and"muscle tension when teeth are not clenched or teeth are not in contact"in patients with chronic pain TMD were higher than those of acute patients,and the difference was statistically significant(P＜0.05).The total OBC scores and daytime OBC scores of chronic pain TMD patients were higher than those of acute pain patients,and the difference was statistically significant(P＜0.05).There was no significant difference in OBC scores of patients with acute and chronic pain TMD during sleep(P＞0.05).Conclusion Pain-related TMD patients had specific oral behaviors,and patients with chronic pain TMD exhibited higher levels of total OBC,daytime OBC,"upper and lower teeth contact when not eating"and"muscle tension when teeth do not bite or teeth are not in contact"oral behavior than acute pain TMD patients.In the treatment of patients with painful TMD,correcting the patient's bad oral behavior can help the treatment of pain-related TMD.

Objective To retrospectively analyze the distribution and differences of oral behavior among patients with acute and chro-nic painassociated with temporomandibular disorders(TMD).Methods A total of 212 patients with pain TMD in West China Hospital of Stomatology completed oral behaviors checklist(OBC).SPSS statistical software was used to analyze all the data.Results The pa-tients with pain-related TMD had specific oral behaviors,such as"pressure on the jaw during sleep"(49.5%),"unilateral chewing"(49.5%),"upper and lower teeth contact when not eating"(37.7%),etc.Scores of"upper and lower teeth contact when not eating"and"muscle tension when teeth are not clenched or teeth are not in contact"in patients with chronic pain TMD were higher than those of acute patients,and the difference was statistically significant(P＜0.05).The total OBC scores and daytime OBC scores of chronic pain TMD patients were higher than those of acute pain patients,and the difference was statistically significant(P＜0.05).There was no significant difference in OBC scores of patients with acute and chronic pain TMD during sleep(P＞0.05).Conclusion Pain-related TMD patients had specific oral behaviors,and patients with chronic pain TMD exhibited higher levels of total OBC,daytime OBC,"upper and lower teeth contact when not eating"and"muscle tension when teeth do not bite or teeth are not in contact"oral behavior than acute pain TMD patients.In the treatment of patients with painful TMD,correcting the patient's bad oral behavior can help the treatment of pain-related TMD.

Objective: To compare the hyoid bone position among patients with different sagittal skeletal malocclusions to provide a reference for clinicians to formulate treatment plans. Methods: Lateral cephalograms of 284 orthodontic patients were selected. According to ANB angles, the types of skeletal malocclusion of patients were determined as follows: Class Ⅰ (1° ≤ ANB ≤ 5°), Class Ⅱ (ANB>5°) and Class Ⅲ (ANB<1°). Ten parameters were used to determine hyoid positions. After comparing the hyoid positions of the three groups, stratified analyses based on sex and age were conducted. Results : No significant differences in demographic and vertical facial type features among skeletal Classes Ⅰ, Ⅱ and Ⅲ patients were observed (P>0.05). The angle between the Gonion-hyoid point line and the hyoid point-Menton line (Go-Hy-Me) of Class Ⅱ patients was significantly smaller than that of Class Ⅰ patients, and the angle between the most anterior and inferior point of the third cervical vertebra-hyoid point line and the hyoid point-Sella line (C3-Hy-S) of Class Ⅲ patients was smaller than that of Class I patients (P<0.05). Age-stratified analysis showed that in the juvenile group, the C3-Hy-S of Class Ⅲ patients was significantly smaller than that of Class Ⅰ patients in males and females (P<0.05). In the adult female group, the Go-Hy-Me of Class Ⅱ patients was significantly smaller, and the distance from the hyoid point to the mandibular plane (Hy-MP) was larger than that noted in Class Ⅰ patients (P<0.05); no significant difference in hyoid position between male Class Ⅱ and I patients was observed (P>0.05). Conclusions Compared with Class Ⅰ patients, the hyoid bone of Class Ⅱ patients in adult females was farther away from the mandible and that of Class Ⅲ patients in juveniles was farther away from the cervical vertebra and posterior cranial base.

This article explores the teaching methods of laparosopic operation training of the begnners. In teaching emphasis should be put on the accumulation of the learners'operation experience,the study of the relative theory,the simulative training and the relative practice.