Objective To reconstruct three-dimensional finite element analysis all-ceramic crowm model of the first maxillary molar.Methods After the CT scanning and image processing to the first maxillary molar in vivo,a 3-D geometric model was established by the Imageware software.The mesh model was then built in Abaqus,the finite element analysis software.Result The three dimensional finite element all-ceramic crown models of the first maxillary molar was constructed on the computer,which had 60 160 nodes and 186 328 tetrahedrons elements.Conclusion The finite element model constructed has the advantages of intact structure and precise elements,can simulate the natural condition and facilitate the further biomechanical research.

Objective: To analyze the clinical features of respiratory epithelial adenomatoid hamartoma (REAH) in the nasal cavity. Methods: Clinical datas of 23 patients, who were hospitalized in Department of Otorhinolaryngology Head and Neck Surgery, the Affiliated Hospital of Qingdao University, from February 2016 to February 2018 with histopathologically proved REAH in the nasal cavity were reviewed. There were 18 males and 5 females, with the age range from 16 to 71 years old. The most common area, main symptoms, surgical methods and follow-up results were analyzed. Results: The most common area was olfactory cleft (21 cases), and the mainly symptom was nasal congestion (18 cases). All the patients received transnasal endoscopic surgery and had no recurrence during following-up from three months to one year. Conclusions The most common area of REAH in the nasal cavity is the olfactory cleft. Histopathological result is needed to make a definite diagnosis. Complete surgical resection is the main treatment.