Objective:To study the reliability modeling method of rehabilitation diagnosis and treatment equipment based on non-homogeneous Poisson process,and to improve the reliability analysis effect of rehabilitation diagnosis and treatment equipment.Methods:Statistics and analysis of the total running time of rehabilitation diagnosis and treatment equipment in a specific period of time were performed,and the trend test of its operation data was conducted.The bathtub curve was used as the trend of rehabilitation diagnosis and treatment equipment failure,under the condition of bathtub curve change trend,a reliability model of non-homogeneous Poisson process of rehabilitation diagnosis and treatment equipment was established.The least squares estimation method was used to estimate the non-homogeneous Poisson process reliability model parameters of rehabilitation diagnosis and treatment equipment,determine the reliability index of rehabilitation diagnosis and treatment equipment,and complete the reliability modeling of rehabilitation diagnosis and treatment equipment.A total of 17 rehabilitation diagnosis and treatment equipment in clinical use in the Second Medical Center of PLA General Hospital from April to October 2022 were selected,including 6 pulse short-wave therapy instruments,5 interference electrical therapy instruments,3 swallowing disorder treatment instruments,and 3 air wave pressure therapy instruments.In July 2022,the reliability modeling method of rehabilitation diagnosis and treatment equipment based on non-homogeneous Poisson process was applied to the management of rehabilitation diagnosis and treatment equipment.The failure rate of rehabilitation diagnosis and treatment equipment before and after the application of the reliability modeling method based on non-homogeneous Poisson process was compared.Results:The average failure rate of 17 rehabilitation diagnosis and treatment equipment was 64.71%(11/17)before application and decreased to 23.53%(4/17)after application,of which the failure rate of 6 pulse shortwave therapy devices decreased from 66.7%(4/6)before application to 16.7%(1/6),the failure rate of 5 interference electrotherapy devices decreased from 60.0%(3/5)before application to 20.0%(1/5),and the failure rate of 3 dysphagia treatment instruments decreased from 66.7%(2/3)to 33.3%before application(1/3),the failure rate of the 3 air wave pressure therapy devices decreased from 66.7%(2/3)before application to 33.3%(1/3).Conclusion:The reliability modeling method for rehabilitation diagnosis and treatment equipment based on non-homogeneous Poisson process can accurately calculate the failure intensity function and cumulative failure intensity function of rehabilitation diagnosis and treatment equipment,reduce the failure rate of rehabilitation diagnosis and treatment equipment,and improve the quality of use of rehabilitation diagnosis and treatment equipment.

Objective:To analyze the three-dimensional radiographic characteristics of calcifying odon-togenic cyst and calcifying epithelial odontogenic tumor using spiral computed tomography(CT)and cone-beam computed tomography(CBCT).Methods:Clinical records,histopathological reports,and CBCT or non-enhanced spiral CT images of 19 consecutive patients with calcifying odontogenic cyst(COC)and 16 consecutive patients with calcifying epithelial odontogenic tumor(CEOT)were retrospec-tively acquired,and radiographic features,including location,size,expansion,internal structure and calcification,were analyzed.Results:Among the 19 COC cases(12 males and 7 females,with an average age of 27 years),89.5％(17/19)of the lesions originated from the anterior and premolar areas,100.0％of them exhibited cortex expansion,and 78.9％had discontinued cortex.Among the 16 CEOT cases(3 males and 13 females,with an average age of 36 years),81.3％(13/16)of the lesions were in the premolar and molar areas,56.3％of them exhibited cortex expansion,and 96.8％had discontinued cortex.According to the distribution of internal calcifications,these lesions were divided in-to:Ⅰ(non-calcification type):absence of calcification;Ⅱ(eccentric marginal type):multiple calcifi-cations scattered along one side of the lesion;Ⅲ(diffused type):numerous calcifications diffusely dis-tributed into the lesion;Ⅳ(plaque type):with a ≥ 5 mm calcified patch;V(peri-coronal type):multiple calcifications clustered around impacted teeth.Calcifications were present in 73.7％of COC le-sions,including 9 type Ⅱ,3 type Ⅲ and 2 type Ⅳ lesions,and 42.8％of CEOT lesions had calcifica-tion images,including 2 type Ⅲ and 5 type V lesions.Six COC lesions had odontoma-like images.Moreover,8 of 9 type Ⅰ CEOTs were histologically Langerhans cell-rich subtype,which had a smaller size(with an average mesiodistal diameter of 17.8 mm)and were not associated with impacted teeth.Conclusion:COC lesions tended to originate from the anterior part of the jaw and exhibit cortex expan-sion,and were sometimes associated with odontoma.CEOT commonly occurred in the posterior jaw and had discontinued cortex.Two lesions had significantly different calcification map.Over 70％of COC le-sions had calcification images,which were mostly scattered along one side of the cysts,far from the im-pacted teeth.Approximately 60％of CEOT lesions exhibited smaller size and non-calcification,and the remaining CEOT cases often had calcification images clustered around the impacted teeth.