Do we need three-dimensional computed tomography in maxillofacial surgery?

In a retrospective clinical study (2000-2003), 121 patients' radiographs and computed tomography scans were reviewed to establish the clinical value of three-dimensional computed tomography. Eighty patients had computed tomography scans; 48 had three-dimensional computed tomography scans for diagnosing facial fractures, 3 for diagnosing temporomandibular joint ankylosis, 1 for tumor with bone destruction, and 1 for a mandibular cyst. It is concluded that axial, coronal, and three-dimensional computed tomography is of crucial importance and should be mandatory for all suspected comminuted and displaced midface fractures instead of plain radiographs. Three-dimensional computed tomography is also recommended for comminuted mandibular fractures and temporomandibular joint ankylosis. Three-dimensional computed tomography is not recommended for the diagnosis of minimally displaced fractures.     

Can magnetic resonance imaging replace single photon computed tomography and computed tomography in detecting bony invasion in patients with oral squamous cell carcinoma?

AIM: To determine whether MRI can replace SPECT and CT in detecting bone invasion in patients with oral SCC. MATERIALS AND METHODS: A retrospective and independent review of the MRI, SPECT, and when available CT, images of 23 patients with oral malignancy who had formal bone resection was undertaken. Our gold standard was histopathology. RESULTS: Bone involvement was seen in 19/23 resections. Sensitivity of MRI was 100% [95% CI 1.0-1.0] and specificity was 75% [95% CI 0.326-1.174]. Sensitivity of SPECT was 100% [95% CI 1.0-1.0] and specificity was 50% [95% CI 0.01-0.99]. CONCLUSIONS: MRI is accurate in predicting bone involvement. The addition of SPECT and CT to routine MRI staging protocols seems no longer indicated. CT may be useful in some selected cases to determine maxillary involvement due to the thinner cortex of the maxilla.     

A new cone-beam computed tomography–driven index for osteoporosis prediction

Clinical Oral Investigations - To verify whether mandibular cortical analyses accurately distinguish postmenopausal women with normal bone mineral density (BMD) from women with osteoporosis by...     

L’analyse morphologique céphalométrique : que peut-elle nous enseigner ?

Cephalometric analysis is an invaluable tool for orthodontists in the diagnosis and treatment planning of their patients. This article discusses the history, development and application of the Björk cephalometric analysis. The advantages and disadvantages of the conventional analysis are discussed and the benefits of using a limited number of parameters are emphasized.     

Accuracy of cone beam computed tomography–derived casts: A comparative study

Statement of problemThe accuracy of the external surface and internal trabecular architecture of large cone beam computed tomography (CBCT)–derived dentomaxillofacial anatomic casts has not yet been thoroughly investigated.PurposeThe purpose of this comparative study was to evaluate the quantitative accuracy of CBCT-derived mandibular casts by applying an innovative land-mark free methodology.Material and methodsFollowing inclusion and exclusion criteria, a CBCT scan of an 18-year-old woman was acquired. The mandible was segmented and isolated from the data set. The segmented mandible included depiction of the cortical surface, trabecular architecture, erupted teeth, and impacted third molars with incomplete root formation. Fifteen mandibular casts were fabricated by using multijet (MJ=4), digital light processing (DLP=4), stereolithography (SLA=2), fused deposition modeling (FDM=2), colorjet (CJ=2), and selective laser sintering (LS=1)-based high-quality medical commercial and office printers. Each printed cast was scanned and superimposed onto the original mandible, and the accuracy of the complete mandible and individual surfaces were assessed with a color-coded map.ResultsWhen the overall combined error associated with complete casts based on printing technology were compared, MJ showed the highest accuracy (0.6 ±0.7 mm). FDM technology (2.2 ±3.4 mm) had the highest overall absolute mean difference. No significant difference was observed when both individual surfaces and the complete mandible were compared.ConclusionsOverall, casts replicated the skeletal and dental anatomic surfaces well. However, shortcomings were observed in relation to depicting trabecular architecture.     

药品"碧兰麻"商品名将更名为"必兰TM"

根据国家食品药品监督管理局药品名称管理的有关规定，法国碧兰公司生产的口腔局部麻醉剂“碧兰麻”，商品名将更名为“必兰^TM”，新货已于2004年底上市。     

正畸支抗之“惑”

与医学其他学科一样,口腔正畸学也不乏用模糊概念来取代精确测量的习惯做法,正畸支抗控制便是其中之一。随着循证医学的发展,正畸医师越来越重视临床证据的准确性,于是,以往对于正畸支抗控制的经验性描述逐渐显露出其弊端。本文根据笔者近年来对支抗的系列研究结果,阐述了最大支抗传统概念的模糊性、定量测量支抗丧失时常被忽略的问题及解决方法,并讨论了最大支抗的限度问题。