Objective To explore the correlation between the actual age and the pulp chamber volume(PCV)and pulp dentinal index(PDI)of the right first molars based on cone beam computed tomog-raphy(CBCT)technology,and to construct an accurate and convenient model for age estimation.Methods CBCT image data of 1 857 Han adults(883 males and 974 females)from the Department of Stomatology,Affiliated Hospital of North Sichuan Medical College were collected.The data were di-vided into training and validation sets at a ratio of 8∶2.A total of 1 485 training samples were used to construct the age estimation model,and 372 samples were used to validate the accuracy of the model.The Mimics 21.0 software was used to measure the PCV and calculate the PDI of the right first molars.Their correlations with age and the differences between different sexes and tooth positions were analyzed.Results Both the PCV and the PDI of the first molars showed strong negative correla-tions with the actual age(r values ranged from 0.82 to 0.89).The differences in PCV and PDI be-tween different sexes and tooth positions were statistically significant(P<0.05).The age estimation model based on PDI was superior to that based on PCV.The model based on the PDI values of the two right first molars(y=73.72-44.15 x3-28.27 x4,where x3 and x4 are the PDI values of the right maxil-lary and mandibular first molars,respectively)was the best,with the R2 of 0.79 and the mean abso-lute error of 4.90 years.Conclusion Both PCV and PDI of the first molars are effective indicators for age estimation.The age estimation model based on the PDI is more convenient and accurate than that based on the PCV,providing a more effective method for age estimation in forensic practice.

Antipyretic-analgesics are currently one of the most prescribed drugs in children.The clinical application of antipyretic-analgesics for children in our country still have irrational phenomenon, which affects the therapeutic effect and even poses hidden dangers to the safety of children.In this paper, suggestions were put forward from the indications, dosage form/route, dosage suitability, pathophysiological characteristics of children with individual differences and drug interactions in the symptomatic treatment of febrile children, so as to provide reference for the general pharmacists when conducting prescription review.

Objective:To investigate the clinical characteristics of old patients with spinal cord injury. Methods:From January 1, 2013 to December 31, 2019, totally 386 old (≥ 60 years) patients with spinal cord injury were enrolled. Their gender, age, etiology, American Spinal Injury Association Impairment Scale (AIS) and complications were analyzed. Results:In the old patients with spinal cord injury, traumatic spinal cord injury was more common in males (71.17%) and non-traumatic spinal cord injury was more common in females (56.19%). Fall on level surface was the most important cause of spinal cord injury both in old men (28.83%) and women (24.76%). Tumor (19.05%) was the most common non-traumatic cause of spinal cord injury in old female patients. Cervical segment (78.46%) was the most common site of injury in old traumatic spinal cord injury, while thoracic segment (52.14%) was the most common site of injury in non-traumatic spinal cord injury. Grade D (38.08%) was the most common AIS grade, followed by grades C (28.76%), A (21.50%), and B (11.66%). Spinal canal stenosis (23.31%) played an important role in the etiology of old spinal cord injury. Neuralgia, venous thrombosis of lower extremities and urinary tract infection were the most common complications in old patients with spinal cord injury. Conclusion:Fall on level surface is the leading cause of spinal cord injury in old patients, and the proportion of fall in the etiology of old spinal cord injury tends to increase with age. It is important to take effective measures to avoid falling in the old adults to prevent spinal cord injury.

Objective:To investigate the outcome of neurological function and the clinical characteristics of complications in children with spinal cord injury. Methods:From 2011 to 2019, children under 15 years old with spinal cord injury were selected in our hospital. Their level of injury and American Spinal Injury Association Impairment Scale (AIS) at one month, three months and one year were recorded. And the complications such as pressure ulcers/scald, urinary tract infection, hydronephrosis/vesicoureteral reflux, constipation, osteoporosis/fracture, deep vein thrombosis, neurodynia, heterotopic ossification, scoliosis and hip dysplasia were analyzed. Results:Of 159 individuals, 41 were boys and 118 were girls, the average age at injury was (6.08±2.57) years. The main cause of spinal cord injury was sports accidents (47.8%), and the main injury sites were thoracic spinal cord injury (89.3%). The cause of spinal cord injury was correlated with age at injury (r = -0.160, P = 0.044), gender (r = -0.458, P < 0.001) and injury sites (r = -0.249, P = 0.002). Complete spinal cord injury counted for 71.7%, and the AIS grade at one month was correlated with that at twelve months (r = 0.984, P < 0.001). The main complications were urinary tract infection (69.2%), constipation (67.9%), hydronephrosis/vesicoureteral reflux (37.7%), scoliosis (25.8%) and hip dysplasia (25.2%). The incidence of ulcers/scald was correlated with injury site (r = 0.179, P = 0.024). The AIS grade three months after injury was significantly correlated with urinary tract infection, constipation, scoliosis and hip dysplasia (|r| > 0.227, P < 0.01). The incidence of ulcers/scald was correlated with osteoporosis/fracture (r = 0.208, P < 0.01). The incidence of urinary tract infection was significantly correlated with hydronephrosis/vesicoureteral reflux, constipation, scoliosis and hip dysplasia (r > 0.261, P < 0.001), as well as osteoporosis/fracture (r = 0.195, P < 0.05). The incidence of hydronephrosis/vesicoureteral reflux was significantly correlated with constipation, osteoporosis/fracture, scoliosis and hip dysplasia (r > 0.146, P < 0.01). The incidence of constipation was significantly correlated with scoliosis and hip dysplasia (r > 0.313, P < 0.01), as well as osteoporosis/fracture (r = 0.160, P < 0.05). The incidence of osteoporosis/fracture was significantly correlated with scoliosis and hip dysplasia (r > 0.342, P < 0.01). The incidence of scoliosis was significantly correlated with hip dysplasia (r = 0.818, P < 0.001). Conclusion:The recovery of neurological function after spinal cord injury in children is closely correlated to AIS. The outcome of complete spinal cord injury is poor. The common complications after spinal cord injury in children demonstrate specific age characteristics, and the incidence of urinary tract infection, constipation, hydronephrosis/vesicoureteral reflux, scoliosis and hip dysplasia are common complications, which need more attention.

Objective:To explore the clinical manifestations and MRI features of pediatric spinal cord injury (SCI) after back bend. Methods:A retrospective study was performed. All the medical records and MRI images of children with SCI after back bend were identified in Beijing Bo'ai Hospital from January 1st, 2002 to August 31st, 2020. Results:A total of 120 SCI children after back bend were reviewed, out of whom 119 cases were girls, one case was boy. The age ranged from 38 to 162 months, with the median age of 76 months. More cases were discovered in July and September every year (32 cases, 26.7%), as well as in weekends (67 cases, 55.8%). The main clinical manifestations were sensory and motor dysfunction of both lower limbs (120 cases, 100%), bladder and bowl incontinence (120 cases, 100%). The common first symptoms included sudden attack of lumbar pain (39 cases, 32.5%), lower limbs paralysis (30cases, 25.0%) and leg pain (10 cases, 8.3%). The peak time of symptoms ranged from five minutes to two days, with the median time of 50 minutes. The MRI features of 104 children with SCI within one week after back bend were as follows: the abnormal signals of MRI in spinal cord involved lower cervical and all the following segments of spinal cord. The number of the segments of spinal cord with abnormal signals ranged from two to 15, with the median of seven segments. The most common segments with abnormal signals were T₉ (96 cases, 92.3%), T₁₀ (96 cases, 92.3%) and T₁₁ (90 cases, 86.5%). Among the cases followed up, 48 cases with complete injury demonstrated a vast and serous spinal cord atrophy (SCA) below the injury segments as early as 37 days after the injury, the SCA would become worse at the chronic stage and maybe involve the spinal cord above the injury segments. In 31 cases with incomplete injury, the abnormal signals of MRI in spinal cord were limited in the lumbar enlargement, with a various degree of SCA at the late stage. All the cases were diagnosed as SCI without radiologic abnormality, out of whom 89 (74.2%) cases suffered from thoracic complete SCI, 31 (25.8%) cases suffered thoracic or lumbar incomplete SCI. The common complications included scoliosis, hip joint dysplasia, urinary tract infection, hydronephrosis, osteoporosis, pathological fracture of lower limbs and valgus knee. Conclusion:The main clinical symptoms of pediatric SCI after back bend were sudden lumbar pain, sensory and motor dysfunction of both lower limbs, and bladder and bowl incontinence. Most of the cases were thoracic complete SCI, the MRI features at the early stage were multiple segments of abnormal signals of spinal cord around T₉ and T₁₀, and later an extensive severe SCA below the injury segments to the conus medullaris, accompanied by the SCA above the injury segments.

Objective:To investigate the occurrence and related factors of autonomic dysreflexia (AD) during intermittent catheterization in patients with spinal cord injury (SCI). Methods:Case control study was used in this study. Intermittent catheterization was performed on 44 SCI patients hospitalized from April, 2019 to April, 2020, The data of age, gender, time after injury, segment of injury, degree of injury, resting blood pressure, immediate blood pressure after catheterization, catheterization numbers, catheterization volume and duration of catheterization were collected. Descriptive analysis and binary Logistic regression analysis were used to analyze the occurrence and related factors of AD. Results:Totally, AD happened in 26 (59.1%) patients. Urethral catheterization was done 1738 times, out of which AD accounted for 187 times (10.8%). The risk of AD increased with the time after injury and age (P < 0.05). The probability of AD was lower in T₇ SCI and below than in T₆ SCI and above (P = 0.002). Catheterization numbers, gender, degree of injury, catheterization volume and duration of catheterization were not influencing factors of AD (P > 0.05). Conclusion:It is necessary to have a full understanding for the occurrence of AD in patients with SCI during intermittent catheterization. For patients with SCI in T₆ and above, long time after injury and elderly patients, routine monitoring of blood pressure during intermittent catheterization is recommended to detect and deal with AD in time.

Objective:To observe the relationship between bone metabolism biochemical markers and clinic features in patients with spinal cord injury. Methods:From July, 2018 to December, 2019, totally 135 patients with spinal cord injury were enrolled. They were assessed with American Spinal Injury Association Impairment Scale (AIS). β-collagen type I C-terminal telopeptide (β-CTX), total N-terminal propeptide of type I precollagen (TP1NP), 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH), serum calcium and serum phosphorus were measured. The level of TP1NP, β-CTX, 25(OH)D and PTH among clinical characteristics (gender, age, disease course, AIS grade and so on) were analyzed. Results:The levels of β-CTX and 25(OH)D were lower in women than in men (|t| > 2.044, P < 0.01). There was difference in the level of 25(OH)D among different ages (F = 3.156, P < 0.05). The levels of β-CTX and TP1NP increased in the first four months after spinal cord injury, and decreased then; while the level of PTH decreased in the first four months, and increased then (P < 0.001). The level of β-CTX was lower in patients of AIS D than in patients of AIS A and C (t >2.679, P < 0.05). The level of TP1NP was higher in paraplegics than in quadriplegics (Z = -2.035, P < 0.05). The level of β-CTX was higher in patients with fractures or surgeries involving bone than in patients without fractures or surgeries involving bone (t = 2.169, P < 0.05). There was no difference in all the bone metabolism markers between patients with and without lower extremity motor function (t < 0.839, Z < 1.822, P > 0.05). The ratio of 25(OH)D deficience was 85.19%. Conclusion:Bone conversion was active in the first four months after spinal cord injury, and decreased gradually then, which may be related to fractures of spine or surgeries involving spine after injury. The effect of spinal cord injury on bone metabolism markers is not clear. Most of patients with spinal cord injury were lack of vitamin D.

Objective:To explore the etiological features and prevention strategies for pediatric spinal cord injury (SCI). Methods:A retrospective study of etiology and demographics features was performed and all the children with SCI (less than 14 years old) were identified in our hospital from January 1st, 2015 to December 31st, 2019. Results:A total of 221 children with SCI were reviewed, with 62 boys and 159 girls. The age ranged from one to 13 years with the median age of six years old. Children aged four to seven years accounted most (55.7%), and were mainly girls (83.7%). Sports and leisure activities (78 cases, 35.3%), non-traumatic causes (56 cases, 25.3%), other traumatic causes (48 cases, 21.7%), transport activities (24 cases, 10.9%) and falling from height (12 cases, 5.4%) were the top five leading causes of pediatric SCI. Among the cases caused by sports and leisure activities, 96.2% (75/78) were related to back bend in dancing exercise, in which most were five to seven years old (80.0%), and all of them were thoracic cord injury without radiologic abnormality, in which 70.7% (53/75) suffered from complete SCI. Conclusion:Pediatric SCI after back bend in dancing exercise is increasing rapidly in recent years. More attention should be paid on education about professional evaluation and the risk of back bend before dancing exercise, and more protective measures should be implemented.

Objective To analyze the colonic transit time in patients with different severities of constipation.Methods From June, 2015 to September, 2017, 73 male patients with supraconal spinal cord injury were grouped as mild constipation group (n = 25) and severe constipation group (n = 48). They were measured the transit time of entire colorectum, ascending colon (including the right colic flexure), transverse colon, descending colon (including the left colic flexure) and rectosigmoid with Abrahamsson method.Results The transit time of entire colorectum, transverse colon, descending colon increased in the severe constipation group compared with that of the mild constipation group (P ＜ 0.05). For each group, the transit time of rectosigmoid was the longest among colon segments (P ＜ 0.05).Conclusion The colonic transit time of SCI male patients with various constipation is different in colon segments. Accurate interventions are needed to target colon segments.

Objective:To explore the modification of the 2019 International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) worksheet and the significance for clinical practice. Methods:The 2019 ISNCSCI worksheet (English version) was compared literally with the 2015 ISNCSCI worksheet (English version) to find the advantages of current version and analyze its significance. Results:Five modifications were found in the 2019 ISNCSCI worksheet, in which the muscle function grading, the sensory grading and how to determine the zone of partial preservation were modified. Conclusion:The ASIA International Standards Committee made prudent modification according to the experience of the 2015 ISNCSCI worksheet to make the worksheet more scientific and clearer for recording.