• Asian Spine Journal
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• 제12권6호
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• pp.1060-1068
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• 2018

Study Design: Retrospective study. Purpose: Lumbar intervertebral disc degeneration is an important cause of low back pain. Overview of Literature: Spinal fusion is often reported to have a good course for adolescent idiopathic scoliosis (AIS). However, many studies have reported that adjacent segment degeneration is accelerated after lumbar spinal fusion. Radiography is a simple method used to evaluate the orientation of the vertebral column. magnetic resonance imaging (MRI) is the method most often used to specifically evaluate intervertebral disc degeneration. The Pfirrmann classification is a well-known method used to evaluate degenerative lumbar disease. After spinal fusion, an increase in stress, excess mobility, increased intra-disc pressure, and posterior displacement of the axis of motion have been observed in the adjacent segments. Methods: we retrospectively secured and analyzed the data of 15 patients (four boys and 11 girls) with AIS who underwent a spinal fusion surgery. We studied the full-length view of the spine (anterior-posterior and lateral) from the X-ray and MRI obtained from all patients before surgery. Postoperatively, another full-length spine X-ray and lumbosacral MRI were obtained from all participants. Then, pelvic tilt, sacral slope, curve correction, and fused and free segments before and after surgery were calculated based on X-ray studies. MRI images were used to estimate the degree to which intervertebral discs were degenerated using Pfirrmann grading system. Pfirrmann grade before and after surgery were compared with Wilcoxon signed rank test. While analyzing the contribution of potential risk factors for the post-spinal fusion Pfirrmann grade of disc degeneration, we used generalized linear models with robust standard error estimates to account for intraclass correlation that may have been present between discs of the same patient. Results: The mean age of the participant was 14 years, and the mean curvature before and after surgery were 67.8 and 23.8, respectively (p<0.05). During the median follow-up of 5 years, the mean degree of the disc degeneration significantly increased in all patients after surgery (p<0.05) with a Pfirrmann grade of 1 and 2.8 in the L2-L3 before and after surgery, respectively. The corresponding figures at L3-L4, L4-L5, and L5-S1 levels were 1.28 and 2.43, 1.07 and 2.35, and 1 and 2.33, respectively. The lower was the number of free discs below the fusion level, the higher was the Pfirrmann grade of degeneration (p<0.001). Conversely, the higher was the number of the discs fused together, the higher was the Pfirrmann grade. Conclusions: we observed that the disc degeneration aggravated after spinal fusion for scoliosis. While the degree of degeneration as measured by Pfirrmann grade was directly correlated by the number of fused segments, it was negatively correlated with the number of discs that remained free below the lowermost level of the fusion.

• 대한소아치과학회지
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• 제48권4호
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• pp.437-448
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• 2021

이 연구의 목적은 상악 유구치의 치근 및 근관의 형태학적 특성을 분석하는 것이다. 2006년 1월부터 2020년 4월까지 서울대학교 치과병원에서 CBCT 및 3D CT를 촬영한 3 - 7세 환자 총 268명(남자 175명, 여자 93명)이 연구에 포함되었으며, 치근 흡수와 치수병변이 없는 총 1002개의 상악 유구치의 치근과 근관 수를 분석하였다. 218개의 치아에 대해 치근과 근관의 형태, 이개각도, 치근과 근관의 길이 및 근관의 단면 형태를 분석하였다. 48개의 치아에 대해서는 Mimics 및 3-Matics software를 사용하여 치근 치수의 부피와 표면적, 치근-치수 비를 측정하였다. 절반 이상이 3개의 치근과 3개의 근관을 가지고 있었다. 좌우측 치아의 대칭성(Cohen's kappa coefficient)은 약 0.63이었다. 치근과 근관의 형태는 상악 제1유구치에서는 직선형이, 제2유구치에서는 곡선형이 많이 관찰되었다. 치근의 이개 정도, 치근과 근관의 길이는 상악 제1, 2유구치 모두 구개측 치근에서 가장 크게 나타났다. 근단부에서 근관의 단면 형태는 주로 ovoid 혹은 round형이었다. 치근 치수의 부피와 표면적, 치근-치수 비는 상악 제1,2유구치 모두 구개측 치근 치수에서 가장 크게 나타났다.