Evaluation of periapical radiographs in the recognition of C-shaped mandibular second molars

AIM: The purpose of this study was to evaluate in a blind trial the efficacy of radiographs to recognize C-shaped mandibular second molars and to determine the incidence of this entity amongst second mandibular molars treated in the Department of Endodontology at the School of Dentistry of the University of Thessaloniki during a seven-year period (1989 - 95). METHODOLOGY: A total of 480 clinical records of root treated mandibular second molars were reviewed. The preoperative, working length, and final radiograph of each tooth alone and in combination were examined in groups as follows: group 1 (preoperative radiographs only), group 2 (working length radiographs), group 3 (final radiographs), group 4 (preoperative and working length radiographs), group 5 (preoperative and final radiographs) and group 6 (all three radiographs). The efficacy of each combination to identify the C-shaped cases was evaluated based on the interpretation of three experienced dentists looking simultaneously at each case. Films were examined on a viewer using a magnifying glass and allowing a two-week interval between groups. Results were compared with the clinical diagnoses stated on the patients' records (group 7). RESULTS: The review of clinical records revealed that 4.58% of second molars had C-shaped canals. Radiographic interpretation was overall more effective when based on film combinations (groups, 4, 5, and 6) than on single radiographs. Amongst the latter, working length radiographs were more helpful than the preoperative and final ones. Preoperative radiographs were the least effective in diagnosing C-shaped cases. CONCLUSIONS: Simultaneous interpretation of preoperative, working length and post-treatment radiographs is important when attempting to diagnose a C-shaped configuration.     

《素问》王冰注使用祖本探讨

根据王冰序,王冰在整理《素问》时使用了不同的版本,但并未说明以何本作祖本。根据对王冰序、《素问》新校正等提供的有关材料进行的分析,认为王冰所用祖本虽源自梁代传本,但不是全元起本,似应是张公秘本;今存《素问》中有些篇文结构应是祖本旧貌;祖本与全元起本、《针灸甲乙经》及《太素》应属不同传本系统。     

The ability of plain radiography to predict intracranial aneurysm occlusion instability during follow-up of endosaccular treatment with Gugliemi detachable coils

Incomplete occlusion of an intracranial aneurysm at follow-up after treatment with Gugliemi detachable coils (GDC) increases the risk of rebleeding and serial angiographic monitoring is therefore currently indicated. We aimed to determine if a change in the plain radiographic appearances of the GDC ball could accurately predict the presence of unstable angiographic occlusion. Paired GDC radiographs (in two planes) and cerebral angiograms, performed immediately after treatment and at follow-up or at two consecutive follow-up examinations, were retrospectively compared. Radiographs were assessed for the radiographic change (loosening, compaction or reorientation) in the coil-ball and angiograms for unstable aneurysm occlusion (neck recurrence or deteriorating occlusion). We compared 49 paired films from 38 patients. Radiographic change in the coil ball had a negative predictive value of 96 %, positive predictive value of 57 % and accuracy of 76 % for the presence of angiographic aneurysm instability. It may be possible to increase the interval between follow-up angiographic examinations after GDC treatment safely if there is no change in the radiographic appearances in two planes. Received: 24 February 2000 Accepted: 16 October 2000     

下颌管及其分支与下颌第三磨牙关系的影像学观察

目的:利用椎形束CT(CBCT)及全景片观察下颌管及其分支在下颌第三磨牙区域的情况。方法 :对179名患者的216颗第三磨牙进行CBCT及全景片检查。在全景片及CBCT上观察下颌管及其分支在第三磨牙区域走向及与第三磨牙的关系。结果:全景片上观察到有4例下颌管有分支,CBCT观察到有22例有分支;下颌管分支与第三磨牙的关系:A类有8例,B类有6例,C类有2例,D类有6例,其中,分支位于第三磨牙颊侧的有7例,舌侧的有6例,位于第三磨牙牙根下方的有9例。结论:利用CBCT可以对下颌管及下颌第三磨牙的空间位置进行更好地观察。CBCT对下颌管分支有更高的检出率。     

Pneumatosis cystoides intestinalis and intramural intestinal gas

Gas in the bowel wall is an unusual but important finding on an abdominal radiograph. The so-called “benign form,” pneumatosis cystoides intestinalis, may be asymptomatic or may cause a variety of symptoms and can result in a bowel obstruction or a sterile pneumoperitoneum. On the other hand, intramural intestinal gas may represent severe underlying disease such as necrotizing enterocolitis or mesenteric vascular occlusion. This finding should be sought when examining abdominal radiographs. A thorough appreciation of the clinical significance of this unusual entity is necessary to make timely therapeutic decisions.     

Comparison of ready-to-use EMDOGAIN®-gel and EMDOGAIN® in patients with chronic adult periodontitis

OBJECTIVES: The aim of this multicenter trial was to compare the clinical and radiographical outcome of a ready-to-use Emdogain-gel (test) with the marketed Emdogain (control). METHODS: Subjects with bilateral infrabony defects > or =4 mm deep and > or =2 mm wide according to radiographs were selected. 88 subjects with probing pocket depth (PPD) > or =6 mm > or =1 month after supervised oral hygiene and scaling participated. At baseline plaque index, bleeding on probing, PPD and probing attachment level were recorded and reproducible radiographs for computer-based bone level measurements were taken. In each subject, 1 tooth was randomly treated with the test and 1 tooth with the control gel. Examinations were repeated 8 and 16 months post-operatively. RESULTS: After 16 months, the mean test PPD was 4.1 mm and the mean control PPD 4.2 mm. The mean gain of attachment was 2.7 mm for test and 2.9 mm for the control sites, and the radiographic measurements demonstrated a mean gain of 1 mm for both test and control sites. CONCLUSION: This series of cases demonstrated a statistically significant reduction of pocket depths and gain of attachment and bone after 8 and 16 months with no difference between the 2 preparations.     

An orthodontic bracket embedded in the medial pterygoid surface: a case report

There is a potential risk that orthodontic brackets can become dislodged into the aerodigestive tract. This case illustrates the management of an orthodontic bracket, which became embedded in the deep tissues of the oropharynx. We aim to highlight the potential risk misplaced dental instruments and materials pose, including that they may become embedded in the soft tissues of the throat and suggest that that this possibility should be considered when they cannot be localized.     

Preoperative imaging of cervical pedicles: comparison of accuracy of oblique radiographs versus axial CT scans

In spite of concerns about safety during their insertion, cervical spine pedicle screws have demonstrated biomechanical superiority over lateral mass screws in several biomechanical studies. One of the concerns for placement of cervical pedicle screws is their small size. Preoperative planning with computed tomography to assess pedicle width has been shown to be extremely accurate and is recommended by several authors. To date there has been no study assessing the accuracy of oblique radiographs for pedicle measurement. We sought to compare accuracy of the oblique radiographic measurements of cervical pedicle width with axial CT scan measurements. Five fresh-frozen human cadaveric cervical spines C3–C7 were studied. Thin cut 1.25 mm computed tomography axial cuts were made through the pedicle isthmus. Oblique radiographs at 35°, 45°, and 55° angles were taken of the right and left pedicles of each specimen using a standardized technique. Each radiograph contained a pin of known length to correct for magnification. All pedicles were again measured and corrected for magnification using the standard pin. Corrected oblique radiograph measurements were compared to CT for each specimen. The outer pedicle width was measured and agreed upon by consensus. The radiograph measurements were on average significantly larger than CT measurements for the pedicles indicating that the pin standard did not completely correct magnification. Plain radiographic data failed to reveal that one oblique angle was favorable to another in terms of magnification or precision. Plain radiographs at oblique angles do not provide accurate measurements of subaxial cervical pedicles at 35°, 45°, or 55° angles. We recommend that thin cut axial CT scans be obtained on all patients prior to transpedicular fixation in the cervical spine. This research was supported by Evanston Northwestern Healthcare Medical Group Orthopaedic Faculty Practice Institutional funds.     

多发骨髓瘤的CT诊断

目的 探讨多发骨髓瘤（multiple myeloma，MM）的X线平片和CT表现特点，提高对MM的认识。方法回顾性分析经骨髓穿刺或临床证实的35例MM的X线平片及CT表现。结果35例MM中，X线平片阴性4例，其中CT亦呈阴性2例。其余病例均有不同程度骨质疏松及骨质破坏。结论MM的X线平片和CT表现具有一定特征，临床、影像、实验室与病理相结合可显著提高本病的诊断准确率。     

髓质海绵肾的影像学诊断（附13例报告）

目的研究髓质海绵肾（MSK）的影像学表现，并提高其诊断准确性。方法临床疑诊MSK的13例患者中，起先8例经X线平片检查，11例经超声检查，7例经CT平扫，其中，3例又经CT增强扫描，随后，11例经静脉肾盂造影（IVP）证实，2例经手术病理证实。对所有患者的影像表现进行了回顾性分析。结果IVP显示集合管呈线状、囊状扩张。X线平片显示肾乳头、髓质区簇状排列的圆形、椭圆形致密影。超声显示围绕肾髓质放射状分布的小回声区和强回声光点。CT平扫示环绕肾小盏分布的点状或簇状结石影，髓质区饱满、明显增大，呈低密度影，增强后，结石影周围的集合管内造影剂蓄积，造成结石影增大的假象。结论IVP是诊断本病例的金标准，但它属于有创性检查，X线平片可作为本病的首选检查方法，而CT能清楚显示肾内结石的形态、大小及分布状况，尤其是髓质增大且呈低密度是本病一新的重要征象之一。