3D cephalometry: a new approach for landmark identification and image orientation

Cephalometry is the scientific study of the measurement of the head in relation to specific reference points. In 3D CT cephalometry, these points are identified on three-dimensional surface models generated from computed tomography scans. In this study a new approach for 3D cephalometry is presented, which should improve reproducibility of the technique and allow accurate comparison of pre- and postoperative data

Relationships Between Vocal Structures, the Airway, and Craniocervical Posture Investigated Using Magnetic Resonance Imaging

Peer reviewedPreprin

The effect of ethnic factor on cephalic index in 17-20 years old females of north of Iran [Efecto del factor étnico en el índice cefálico en mujeres entre 17 y 20 años de edad del norte de Irán]

Cephalic index and head shape are affected by geographical, gender, age, racial and ethnic factors. This study was carried out to determine cephalic index and head shape in 17-20 years old female in Gorgan, North of Iran. This descriptive and cross sectional study is undertaken on 410 normal 17-20 years old female (Turkman group: n=203, Fars group: n=207). The study was done by classic cephalometry in Gorgan North of Iran. Means and SD of cephalic index was 85 ± 4.5 and 82.8 ± 3.6 in native Fars and Turkman groups, respectively. Dominant and rare type of head shape in native Fars group were hyperbrachycephalic (53.6%) and dolichocephalic (15%), and in Turkman group were brachycephalic (58.1%) and dolichocephalic (0.05%), respectively. With noticing of our results and other studies in the world, we can conclude that the role of ethnic factor on head dimensions. © 2007 Sociedad Chilena de Anatomía

The Reliability Of Facial Soft Tissue Landmarks With Photogrammetry

Introduction:With attention being given to the deleterious effects of radiation exposure from dental radiographs and inaccuracies in cephalometric soft tissue measurements, an alternative method of facial analysis with sufficiently reliable soft tissue landmarks should be developed. The goals of this study were threefold: (1) to define a new, low-cost method for capturing standardized frontal and sagittal facial images, (2) to determine on which photographic view that landmarks can be more reliably located, and (3) to determine which landmarks are appropriate for quantitative facial analysis. Materials and Methods:Simultaneous frontal and right sagittal facial images of 10 male and 10 female dental student subjects were captured using high-definition webcams as part of a low-cost set-up. Seventeen identical predefined facial soft tissue landmarks were located by 5 examiners on both types of images and were recorded as coordinate values. These coordinate values were used to calculate the best estimate of the true value for each landmark, mean deviation from this best estimate, and reliability in the X- and Y-axes using the Shrout-Fleiss intraclass correlation coefficient with corresponding 95% confidence intervals. Two examiners repeated the landmark location to evaluate intra-examiner reliability. Results:With a 95% confidence interval range of \u3e0.950, nose and mouth landmarks were among the most reliable landmarks on frontal and sagittal facial images. Converselyright soft tissue gonionwas one of the least reliable landmarks located in this study. In general, landmarks located by a single examiner showed greater reliability than when there were multiple examiners. Conclusions:This low-cost method yielded frontal and sagittal images sufficient for landmark identification. The magnitude of error varies between landmarks, is largest for poorly demarcated landmarks, and most had a non-circular envelope of error. Certain landmarks were more reliable on sagittal images and others were more reliable on frontal images. All landmarks had greater reliability and less mean deviation when located by a single examiner

Repeatability of facial soft tissue thickness measurements for forensic facial reconstruction using X-ray images

The repeatability of facial soft tissue thickness measurements at 10 standard anatomical landmarks was evaluated using lateral X-ray images obtained from 50 adult subjects. The intra-and inter-observer error rates were calculated after four practitioners took measurements using Denta Pacs 8.1 software. The results indicated high inter- and intra-observer repeatability, suggesting X-ray images can be used to measure facial soft tissue thicknesses for the purpose of craniofacial reconstruction and superimposition

The variation of head shapes in 17-20 years old native fars male in Gorgan-North of Iran

Cephalic index and head shape are affected by geographical, gender, age and racial factors. This study carried out to determine cephalic index and head shape in 17-20 years old native Fars male in Gorgan, North of Iran. This descriptive study was done on 200 of 17-20 years old male native Fars by classic cephalometry in Gorgan, North of Iran. Mean and SD of cephalic index was 84.8 ± 6.9. The head shape of 52% of individuals was hyperbrachycephalic, 25% brachycephalic, 21.5% mesocephalic and 1.5% dolichocephalic. Native Fars individuals showed typical hyperbrachycephalic. In comparing to other studies in world, we can conclude that the role of racial/ethnic factor in cephalic diameters. © 2006 Sociedad Chilena de Anatomía

A new method for improved standardisation in three-dimensional computed tomography cephalometry

Interest for three-dimensional computed tomography cephalometry has risen over the last two decades. Current methods commonly rely on the examiner to manually point-pick the landmarks and/or orientate the skull. In this study, a new approach is presented, in which landmarks are calculated after selection of the landmark region on a triangular model and in which the skull is automatically orientated in a standardised way. Two examiners each performed five analyses on three skull models. Landmark reproducibility was tested by calculating the standard deviation for each observer and the difference between the mean values of both observers. The variation can be limited to 0.1 mm for most landmarks. However, some landmarks perform less well and require further investigation. With the proposed reference system, a symmetrical orientation of the skulls is obtained. The presented methods contribute to standardisation in cephalometry and could therefore allow improved comparison of patient data

Morphological evaluation of head in Turkman males in Gorgan-North of Iran

Cephalometry or measurement of human head is used in identification, forensic medicine, plastic surgery, orthodontics, archeology and examine the differences between races and ethnicities. This descriptive investigation was undertaken on 198 young Turkman males to determine the cephalic index and head phenotype among them in Gorgan, North of Iran. In this study cephalic index was determined by classic cephalometric method. Mean and standard deviation of cephalic index was 80.4 ± 4. Based on the cephalic index, the head shape of 42.4% of individuals were brachycephalic, 7.6% hyperbrachycephalic, 40.9% mesocephalic and 8.1% dolicocephalic. This research showed that Turkman individuals have typical brachycephalic phenotype. In comparison to other studies, we can conclude that the ethnic factor has an effective role on head phenotype in North of Iran

Looking at the Unborn: Historical aspects of obstetric ultrasound

Edited trascript of a Witness Seminar held at the Wellcome Institute for the History of Medicine,in London, on 10 March 1998. First published by the Wellcome Trust, 2000. ©The Trustee of the Wellcome Trust, London, 2000. All volumes are freely available online at: www.history.qmul.ac.uk/research/modbiomed/wellcome_witnesses/Annotated and edited transcript of a Witness Seminar held on 10 March 1998. Introduction by E M Tansey.Annotated and edited transcript of a Witness Seminar held on 10 March 1998. Introduction by E M Tansey.Annotated and edited transcript of a Witness Seminar held on 10 March 1998. Introduction by E M Tansey.Annotated and edited transcript of a Witness Seminar held on 10 March 1998. Introduction by E M Tansey.The obstetric ultrasound scanner had its major origins in a programme of research undertaken in Glasgow in the 1950s and 1960s, under the leadership of the obstetrician, Professor Ian Donald. Donald’s work was characterized by a remarkable series of collaborations between engineers and clinicians, many of whom took part in this Witness Seminar to consider the early history of ultrasound imaging, its technical development and significant clinical applications in the diagnosis of fetal abnormalities. Technical and engineering developments of the scanner were discussed and it was practical demonstrations of the early scanners that gradually convinced the majority of obstetricians to invest time and training in this new technology. Participants include: Mr Usama Abdulla, Mr Thomas Brown, Professor Dugald Cameron, Professor Stuart Campbell, Mr John Fleming, Professor John MacVicar, Professor Peter Wells and Dr James Willocks. Tansey E M, Christie D A. (eds) (2000) Looking at the unborn: Historical aspects of obstetric ultrasound, Wellcome Witnesses to Twentieth Century Medicine, vol. 5. London: The Wellcome Trust.The Wellcome Trust is a registered charity, no. 210183

Relationship between bridging and dimensions of sella turcica with classification of craniofacial skeleton

Purpose: In orthodontics, it is essential to determine the craniofacial skeleton pattern (class I, II, III) for planning treatment. Sella turcica bridging that is seen on lateral cephalometric radiographs is considered as a normal finding. This study aimed to compare sella turcica bridging and its dimensions in patients with various craniofacial patterns. Material and methods: A total of 105 lateral cephalometric radiographs (53 men and 52 women), aged 14-26 years, were randomly and equally assigned to three groups of class I, II, and III, respectively. The length, diameter, and depth of the sella turcica as well as sella turcica bridging were determined on radiographs. The chi-squared test was used for assessing the relationship between sella turcica bridging and craniofacial skeleton classification. ANOVA was used for assessing the relationship between the dimensions of the sella turcica and craniofacial skeleton classification. The Pearson's correlation coefficient was used for assessing the relationship between age and the dimensions of the sella turcica. Results: The sella turcica had a normal shape in 64.76% of patients, whereas 35.33% of patients had sella turcica bridging. In total, 11.42% of patients belonged to class I, 34.28% to class II, and 66.62% to class III. The diameter of the sella turcica had a significant relationship with age; the diameter of the sella turcica increased with age (p < 0.001). Conclusions: There is a significant relationship between craniofacial skeleton patterns and sella turcica bridging, i.e., the incidence of sella turcica bridging is higher in class III patients. The sella turcica had a greater diameter in older patients