Abstract: 【Abstract】 Objective To analyze the pathogenesis factors in Sagliker Syndrome (SS) associated with severe secondary hyperparathyroidism (SHPT), and to characterize and measure the craniofacial deformities in SS.  Methods We recruited 8 SS patients and 26 simple SHPT patients diagnosed in the Department of Nephrology and Department of Dental Medical Center, China-Japan Friendship Hospital. Gender, age, cause of SHPT, dialysis age and blood biochemical parameters were compared between SS patients and simple SHPT patients. Liner regression was used to disclose the relationship between blood biochemical parameters and SS. We also selected 8 SS patients and 8 simple SHPT patients to characterize their craniofacial morphology by cephalometry on skull radiographic images. Results The male/female ratio was 0.6:1 and 1:1 (P＜0.05), the average age was 44.38 and 51.15 years (P＜0.05), and the average dialysis vintage was 145 and 125 months (P＜0.05), the average ALP was 1184 U/L and 491 U/L (P＜0.01), and the average iPTH was 2109 pg/ml and 2371 pg/ml (P＞0.05), in SS patients and simple SHPT patients, respectively. In SS patients, the maxillary body enlarged especially in sagittal and vertical directions, the anterior part of mandibula increased in the vertical direction without any other changes in this bone, and the soft tissues around mandibula changed compatible with the osseous deformities but without compensatory transposition of teeth. Conclusions Gender, age, dialysis age and several blood biochemical abnormalities may be the risk factors for SS. Craniofacial changes are found exclusively at specific sites in SS. Several yet unknown mechanisms drive higher serum ALP level and osseous deformities predominantly in craniofacial sites rather than in other skeletons in SS. 通信作者：基金项目：北京市首都医学发展科研基金研究资助项目(2009-3023)

Key words: Sagliker Syndrome, Secondary hyperparathyroidism, Cephalometry