Tron Darvann - Academia.edu (original) (raw)

Papers by Tron Darvann

Research paper thumbnail of A study of familial Char syndrome involving the TFAP2B gene with a focus on facial shape characteristics

Clinical Dysmorphology, 2018

In this case study, we investigate a child presenting with patent ductus arteriosus, short philtr... more In this case study, we investigate a child presenting with patent ductus arteriosus, short philtrum, duck-bill lips, strabismus, a flat nasal bridge, a broad forehead, low-set ears, hypertelorism, up-slanting palpebral fissures, almondshaped eyes, and hypodontia, all leading to the clinical diagnosis of Char syndrome. Genetic analysis showed heterozygosity for the novel variant c.851T > C, p. Leu284Ser in the TFAP2B gene. Family analysis suggested that at least 20 members, extending six generations back, were affected. All 10 members available for genetic testing were heterozygous for the novel pathogenic variant. Qualitative analysis of the facial dysmorphology in the proband and three of the affected family members using three-dimensional surface scanning showed that the major deviations were observed in the forehead/eyebrow, nose, upper lip, and chin regions with, for example, a flattened nose and reduced height of the upper lip and the face. Furthermore, it is suggested that Char syndrome is associated with disturbances of tooth formation and eruption.

Research paper thumbnail of Accuracy and precision of manual segmentation of the maxillary sinus in MR images-a method study

The British journal of radiology, 2018

To assess the accuracy and precision of segmentation of the maxillary sinus in MR images to evalu... more To assess the accuracy and precision of segmentation of the maxillary sinus in MR images to evaluate the potential usefulness of this modality in longitudinal studies of sinus development. A total of 15 healthy subjects who had been both craniofacial CT and MR scanned were included and the 30 maxillary sinus volumes were evaluated using segmentation. Two of the authors did segmentation of MRI and one of these authors did double segmentation. Agreement in results between CT and MRI as well as inter- and intraexaminer errors were evaluated by statistical and three-dimensional analysis. The intraclass correlation coefficient for volume measurements for both method error, inter- and intraexaminer agreement were > 0.9 [maximal 95% confidence interval of 0.989-0.997, p < 0.001] and the limit of agreement for all parameters were < 5.1%. Segmentation errors were quantified in terms of overlap [Dice Coefficient (DICE) > 0.9 = excellent agreement] and border distance [95% percenti...

Research paper thumbnail of Prenatal diagnosis of autosomal recessive Robinow syndrome using 3D ultrasound

Clinical case reports, 2017

This article hypothesizes that it is possible to detect and diagnose both the autosomal recessive... more This article hypothesizes that it is possible to detect and diagnose both the autosomal recessive and dominant forms prenatally using ultrasound. By focusing on the characteristic phenotypical presentation, the examinator is able to diagnose the syndrome prenatally, which is of clinical importance to the parents and counseling for the consideration of terminating the pregnancy.

Research paper thumbnail of Facial morphology in children and adolescents with juvenile idiopathic arthritis and moderate to severe temporomandibular joint involvement

American Journal of Orthodontics and Dentofacial Orthopedics, 2016

The aims of this study were to (1) assess lateral facial morphology in children and adolescents w... more The aims of this study were to (1) assess lateral facial morphology in children and adolescents with juvenile idiopathic arthritis and moderate to severe temporomandibular joint (TMJ) involvement, (2) compare the lateral facial morphology of these subjects with and without TMJ involvement using cephalograms and 3-dimensional (3D) facial photographs, and (3) compare and correlate the results of the 3D photographic and cephalometric analyses. Sixty patients with juvenile idiopathic arthritis were included and grouped as follows: group 1, juvenile idiopathic arthritis patients without TMJ involvement; group 2, juvenile idiopathic arthritis patients with moderate to severe unilateral TMJ involvement; and group 3, juvenile idiopathic arthritis patients with moderate to severe bilateral TMJ involvement. Lateral cephalograms were used to assess and compare lateral facial morphologies between the groups. Lateral projections of oriented 3D photographs were superimposed on the lateral cephalograms. The results of the lateral 3D photographic analysis were correlated with those of lateral cephalometric analysis. Group 3 showed the most severe growth disturbances, including more retrognathic mandible and retruded chin, steep occlusal and mandibular planes, and more hyperdivergent type (P &amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01). Group 2 showed similar growth disturbances, but to a lesser extent than did group 3. Photographic variables were significantly correlated with the soft tissue and skeletal variables of cephalograms (0.5 &amp;amp;amp;amp;amp;amp;amp;amp;lt; r &amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.9; P &amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). Subjects with juvenile idiopathic arthritis and unilateral or bilateral moderate to severe TMJ involvement had significant growth disturbances. Early intervention is recommended for these patients to prevent unfavorable facial development. Furthermore, with proper orientation, 3D photographs can be used as an alternative to conventional lateral cephalograms and 2-dimensional photographs.

Research paper thumbnail of The Foucault Test for Solar Telescopes

Research paper thumbnail of Solar horizontal flows and differential rotation determined by local correlation tracking of granulation /

Research paper thumbnail of Cross Correlation of Images of Solar Fine Structure and Possible Applications - a Progress Report

Research paper thumbnail of Influence of seeing on measurements of horizontal flows in the solar photosphere

Research paper thumbnail of Round table discussion

Research paper thumbnail of Computation of photospheric horizontal flows by local correlation tracking of granulation

Research paper thumbnail of Design of the LEST Slow Wavefront Sensor

Research paper thumbnail of Prestudy of a FPI filter for LEST

Research paper thumbnail of Measurements of Horizontal Flows in 1.6 µ m Granulation

Infrared Solar Physics, 1994

We report on a first analysis of the horizontal motions in a 45 minute (32 X 22 arcsec 2 field of... more We report on a first analysis of the horizontal motions in a 45 minute (32 X 22 arcsec 2 field of view) granulation time series (movie presented at the present IAU Symposium) obtained at 1.6 μπι with the Vacuum Tower Telescope (VTT) of the National Solar Observatory at Sacramento Peak (NSO/SP). High signal/noise flow maps are obtained by use of the local cross correlation technique (November 1986) which incorporates efficient attenuation of seeing and 5-min oscillar tions. The flow pattern, showing a (« 30 arcsec diameter) supergranule with (« 8-15 arcsec) mesogranules superposed, is long lived compared to the 45 min of observations. The computed flows (velocity, divergence, vorticity) resemble the ones obtained at visible wavelengths (e.^., by Brandt et al. 1991, November 1989, November and Simon 1988, Simon et al. 1988). The high quality of the the flow maps (due to a large number of selected images (1500), and (supposedly) smaller 5-min oscillations and better seeing conditions at 1.6 μτη) allows us to study time evolution (resolution « 15 min) of the details of the flow (spatial resolution « 3 arcsec). An interesting new finding is the short lifetime (< 4 5 min) of vorticity as opposed to the long lived 45 min) divergence of the flow. Our study demonstrates the possibility of using the 1.6 μιη window to the opacity minimum region to study the horizontal flows at these deep layers of the photosphere.

Research paper thumbnail of <title>Midsagittal surface measurement of the head: an assessment of craniofacial asymmetry</title>

Medical Imaging 1999: Image Processing, 1999

ABSTRACT

Research paper thumbnail of High resolution analysis of quiescent prominences at NSO / Sacramento Peak observatory

Lecture Notes in Physics, 1990

Research paper thumbnail of Finite element analysis of tibial fractures

Danish medical bulletin, 2010

Fractures of the tibial shaft are relatively common injuries. There are indications that tibial s... more Fractures of the tibial shaft are relatively common injuries. There are indications that tibial shaft fractures share characteristics in terms of site, type and local fracture mechanisms. In this study, we aimed to set up a mathematical, computer-based model using finite element analysis of the bones of the lower leg to examine if such a model is adequate for prediction of fracture locations and patterns. In future studies, we aim to use these biomechanical results to examine fracture prevention, among others, and to simulate different types of osteosynthesis and the process of bony healing. The biomechanical results are the basis for fracture healing, biomechanical fall analysis and stability analysis of osteosynthesis. A finite element model of the bony part of the lower leg was generated on the basis of computed tomography data from the Visible Human Project. The data consisted of 21,219 3D elements with a cortical shell and a trabecular core. Three types of load of torsion, a di...

Research paper thumbnail of Quantitative ultrasound tissue characterization in shoulder and thigh muscles--a new approach

BMC musculoskeletal disorders, Jan 18, 2006

The echogenicity patterns of ultrasound scans contain information of tissue composition in muscle... more The echogenicity patterns of ultrasound scans contain information of tissue composition in muscles. The aim was: (1) to develop a quantitative ultrasound image analysis to characterize tissue composition in terms of intensity and structure of the ultrasound images, and (2) to use the method for characterization of ultrasound images of the supraspinatus muscle, and the vastus lateralis muscle. Computerized texture analyses employing first-order and higher-order grey-scale statistics were developed to objectively characterize ultrasound images of m. supraspinatus and m. vastus lateralis from 9 healthy participants. The mean grey-scale intensity was higher in the vastus lateralis muscle (p < 0.05) than in the supraspinatus muscle (average value of middle measuring site 51.4 compared to 35.0). Furthermore, the number of spatially connected and homogeneous regions (blobs) was higher in the vastus lateralis (p < 0.05) than in the supraspinatus (average for m. vastus lateralis: 0.092...

Research paper thumbnail of Anomalies of craniofacial skeleton and teeth in cleidocranial dysplasia

Journal of craniofacial genetics and developmental biology

Mutations involving the transcription factor CBFA1 cause cleidocranial dysplasia (CCD) in man. Re... more Mutations involving the transcription factor CBFA1 cause cleidocranial dysplasia (CCD) in man. Recently, a mouse model of CCD has been generated (Cbfal +/-) [Komori et al., 1997], and disturbances of osteoclast differentiation have been documented. It has been shown that these animals exhibit hypoplastic clavicles and nasal bones, and retarded ossification of parietal, interparietal, and supraoccipital bones. Humans with CCD show all these features, including severely retarded ossification of the cranial base, strongly suggesting that both intramembranous ossification and endochondral ossification are affected. In addition, CCD patients have multiple supernumerary teeth and delayed tooth eruption. The present report presents 3D reconstructions of computerised tomography (CT) scans of the craniofacial region of a CCD boy examined at both 1 and 7 years of age. The anomalies in craniofacial skeleton and teeth are analysed and compared to the findings of our previous clinical studies an...

Research paper thumbnail of An automated procedure for measurement of prominence transverse velocities

Lecture Notes in Physics

A computer algorithm for measurment of transverse velocities (proper motion) in prominences has b... more A computer algorithm for measurment of transverse velocities (proper motion) in prominences has been developed. We present the method and examples of computed proper motion maps. The method is a modified version of the local cross correlation technique previously applied to granulation images (November 1986, Title et al 1987, November and Simon 1988, November 1988, Darvann 1988, Brandt et al

Research paper thumbnail of Sagittal synostosis: I. Preoperative morphology of the skull

Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery, 2006

The aim of this study was to characterise the preoperative morphology of the skull in sagittal sy... more The aim of this study was to characterise the preoperative morphology of the skull in sagittal synostosis in an objective and quantified way. The shapes of the skulls of 105 patients with isolated premature synostosis of the sagittal suture (SS group) were studied and compared with those of a control group of 72 children with unilateral incomplete cleft lip (UICL). A standardised radiocephalometric technique was used to obtain the images. A modification of a method developed by Kreiborg was used to analyse the radiocephalograms, which included the digitisation of 88 landmarks in the calvaria, skull base, and orbit (42 in the lateral and 46 in the frontal projections), the production of plots of mean shape for each group, and the intergroup comparison of a series of 81 variables (linear distance between selected landmarks, and angles defined by groups of three landmarks). Data from a subgroup of 66 patients aged 5 to 8 months were further compared to age-matched normative data in terms of seven angular and linear calvarial, cranial base and orbital variables. In a comparative analysis of the mean lateral plots, the foreheads of the study group (SS) had a more pronounced anterior slope and were also more convex. The vertex area was located more anteriorly, and was less convex. The occipital curvature was more prominent. Analysis of the mean frontal plots revealed a lack in convexity and lateral projection of the upper parietal regions, as well as a lower location of the line of maximum skull width. Comparison of the mean values of an SS subgroup to age-matched normative data showed a longer (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and narrower skull (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and a greater interorbital distance (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). The cranial base angle, the sella to nasion, and sella to basion lengths did not differ significantly. Sagittal synostosis is characterised by an extensive deformity of the cranial vault, with an essentially normal cranial base. The widened interorbital distance is probably related to compensatory metopic hyperactivity.

Research paper thumbnail of A study of familial Char syndrome involving the TFAP2B gene with a focus on facial shape characteristics

Clinical Dysmorphology, 2018

In this case study, we investigate a child presenting with patent ductus arteriosus, short philtr... more In this case study, we investigate a child presenting with patent ductus arteriosus, short philtrum, duck-bill lips, strabismus, a flat nasal bridge, a broad forehead, low-set ears, hypertelorism, up-slanting palpebral fissures, almondshaped eyes, and hypodontia, all leading to the clinical diagnosis of Char syndrome. Genetic analysis showed heterozygosity for the novel variant c.851T > C, p. Leu284Ser in the TFAP2B gene. Family analysis suggested that at least 20 members, extending six generations back, were affected. All 10 members available for genetic testing were heterozygous for the novel pathogenic variant. Qualitative analysis of the facial dysmorphology in the proband and three of the affected family members using three-dimensional surface scanning showed that the major deviations were observed in the forehead/eyebrow, nose, upper lip, and chin regions with, for example, a flattened nose and reduced height of the upper lip and the face. Furthermore, it is suggested that Char syndrome is associated with disturbances of tooth formation and eruption.

Research paper thumbnail of Accuracy and precision of manual segmentation of the maxillary sinus in MR images-a method study

The British journal of radiology, 2018

To assess the accuracy and precision of segmentation of the maxillary sinus in MR images to evalu... more To assess the accuracy and precision of segmentation of the maxillary sinus in MR images to evaluate the potential usefulness of this modality in longitudinal studies of sinus development. A total of 15 healthy subjects who had been both craniofacial CT and MR scanned were included and the 30 maxillary sinus volumes were evaluated using segmentation. Two of the authors did segmentation of MRI and one of these authors did double segmentation. Agreement in results between CT and MRI as well as inter- and intraexaminer errors were evaluated by statistical and three-dimensional analysis. The intraclass correlation coefficient for volume measurements for both method error, inter- and intraexaminer agreement were > 0.9 [maximal 95% confidence interval of 0.989-0.997, p < 0.001] and the limit of agreement for all parameters were < 5.1%. Segmentation errors were quantified in terms of overlap [Dice Coefficient (DICE) > 0.9 = excellent agreement] and border distance [95% percenti...

Research paper thumbnail of Prenatal diagnosis of autosomal recessive Robinow syndrome using 3D ultrasound

Clinical case reports, 2017

This article hypothesizes that it is possible to detect and diagnose both the autosomal recessive... more This article hypothesizes that it is possible to detect and diagnose both the autosomal recessive and dominant forms prenatally using ultrasound. By focusing on the characteristic phenotypical presentation, the examinator is able to diagnose the syndrome prenatally, which is of clinical importance to the parents and counseling for the consideration of terminating the pregnancy.

Research paper thumbnail of Facial morphology in children and adolescents with juvenile idiopathic arthritis and moderate to severe temporomandibular joint involvement

American Journal of Orthodontics and Dentofacial Orthopedics, 2016

The aims of this study were to (1) assess lateral facial morphology in children and adolescents w... more The aims of this study were to (1) assess lateral facial morphology in children and adolescents with juvenile idiopathic arthritis and moderate to severe temporomandibular joint (TMJ) involvement, (2) compare the lateral facial morphology of these subjects with and without TMJ involvement using cephalograms and 3-dimensional (3D) facial photographs, and (3) compare and correlate the results of the 3D photographic and cephalometric analyses. Sixty patients with juvenile idiopathic arthritis were included and grouped as follows: group 1, juvenile idiopathic arthritis patients without TMJ involvement; group 2, juvenile idiopathic arthritis patients with moderate to severe unilateral TMJ involvement; and group 3, juvenile idiopathic arthritis patients with moderate to severe bilateral TMJ involvement. Lateral cephalograms were used to assess and compare lateral facial morphologies between the groups. Lateral projections of oriented 3D photographs were superimposed on the lateral cephalograms. The results of the lateral 3D photographic analysis were correlated with those of lateral cephalometric analysis. Group 3 showed the most severe growth disturbances, including more retrognathic mandible and retruded chin, steep occlusal and mandibular planes, and more hyperdivergent type (P &amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01). Group 2 showed similar growth disturbances, but to a lesser extent than did group 3. Photographic variables were significantly correlated with the soft tissue and skeletal variables of cephalograms (0.5 &amp;amp;amp;amp;amp;amp;amp;amp;lt; r &amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.9; P &amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). Subjects with juvenile idiopathic arthritis and unilateral or bilateral moderate to severe TMJ involvement had significant growth disturbances. Early intervention is recommended for these patients to prevent unfavorable facial development. Furthermore, with proper orientation, 3D photographs can be used as an alternative to conventional lateral cephalograms and 2-dimensional photographs.

Research paper thumbnail of The Foucault Test for Solar Telescopes

Research paper thumbnail of Solar horizontal flows and differential rotation determined by local correlation tracking of granulation /

Research paper thumbnail of Cross Correlation of Images of Solar Fine Structure and Possible Applications - a Progress Report

Research paper thumbnail of Influence of seeing on measurements of horizontal flows in the solar photosphere

Research paper thumbnail of Round table discussion

Research paper thumbnail of Computation of photospheric horizontal flows by local correlation tracking of granulation

Research paper thumbnail of Design of the LEST Slow Wavefront Sensor

Research paper thumbnail of Prestudy of a FPI filter for LEST

Research paper thumbnail of Measurements of Horizontal Flows in 1.6 µ m Granulation

Infrared Solar Physics, 1994

We report on a first analysis of the horizontal motions in a 45 minute (32 X 22 arcsec 2 field of... more We report on a first analysis of the horizontal motions in a 45 minute (32 X 22 arcsec 2 field of view) granulation time series (movie presented at the present IAU Symposium) obtained at 1.6 μπι with the Vacuum Tower Telescope (VTT) of the National Solar Observatory at Sacramento Peak (NSO/SP). High signal/noise flow maps are obtained by use of the local cross correlation technique (November 1986) which incorporates efficient attenuation of seeing and 5-min oscillar tions. The flow pattern, showing a (« 30 arcsec diameter) supergranule with (« 8-15 arcsec) mesogranules superposed, is long lived compared to the 45 min of observations. The computed flows (velocity, divergence, vorticity) resemble the ones obtained at visible wavelengths (e.^., by Brandt et al. 1991, November 1989, November and Simon 1988, Simon et al. 1988). The high quality of the the flow maps (due to a large number of selected images (1500), and (supposedly) smaller 5-min oscillations and better seeing conditions at 1.6 μτη) allows us to study time evolution (resolution « 15 min) of the details of the flow (spatial resolution « 3 arcsec). An interesting new finding is the short lifetime (< 4 5 min) of vorticity as opposed to the long lived 45 min) divergence of the flow. Our study demonstrates the possibility of using the 1.6 μιη window to the opacity minimum region to study the horizontal flows at these deep layers of the photosphere.

Research paper thumbnail of <title>Midsagittal surface measurement of the head: an assessment of craniofacial asymmetry</title>

Medical Imaging 1999: Image Processing, 1999

ABSTRACT

Research paper thumbnail of High resolution analysis of quiescent prominences at NSO / Sacramento Peak observatory

Lecture Notes in Physics, 1990

Research paper thumbnail of Finite element analysis of tibial fractures

Danish medical bulletin, 2010

Fractures of the tibial shaft are relatively common injuries. There are indications that tibial s... more Fractures of the tibial shaft are relatively common injuries. There are indications that tibial shaft fractures share characteristics in terms of site, type and local fracture mechanisms. In this study, we aimed to set up a mathematical, computer-based model using finite element analysis of the bones of the lower leg to examine if such a model is adequate for prediction of fracture locations and patterns. In future studies, we aim to use these biomechanical results to examine fracture prevention, among others, and to simulate different types of osteosynthesis and the process of bony healing. The biomechanical results are the basis for fracture healing, biomechanical fall analysis and stability analysis of osteosynthesis. A finite element model of the bony part of the lower leg was generated on the basis of computed tomography data from the Visible Human Project. The data consisted of 21,219 3D elements with a cortical shell and a trabecular core. Three types of load of torsion, a di...

Research paper thumbnail of Quantitative ultrasound tissue characterization in shoulder and thigh muscles--a new approach

BMC musculoskeletal disorders, Jan 18, 2006

The echogenicity patterns of ultrasound scans contain information of tissue composition in muscle... more The echogenicity patterns of ultrasound scans contain information of tissue composition in muscles. The aim was: (1) to develop a quantitative ultrasound image analysis to characterize tissue composition in terms of intensity and structure of the ultrasound images, and (2) to use the method for characterization of ultrasound images of the supraspinatus muscle, and the vastus lateralis muscle. Computerized texture analyses employing first-order and higher-order grey-scale statistics were developed to objectively characterize ultrasound images of m. supraspinatus and m. vastus lateralis from 9 healthy participants. The mean grey-scale intensity was higher in the vastus lateralis muscle (p < 0.05) than in the supraspinatus muscle (average value of middle measuring site 51.4 compared to 35.0). Furthermore, the number of spatially connected and homogeneous regions (blobs) was higher in the vastus lateralis (p < 0.05) than in the supraspinatus (average for m. vastus lateralis: 0.092...

Research paper thumbnail of Anomalies of craniofacial skeleton and teeth in cleidocranial dysplasia

Journal of craniofacial genetics and developmental biology

Mutations involving the transcription factor CBFA1 cause cleidocranial dysplasia (CCD) in man. Re... more Mutations involving the transcription factor CBFA1 cause cleidocranial dysplasia (CCD) in man. Recently, a mouse model of CCD has been generated (Cbfal +/-) [Komori et al., 1997], and disturbances of osteoclast differentiation have been documented. It has been shown that these animals exhibit hypoplastic clavicles and nasal bones, and retarded ossification of parietal, interparietal, and supraoccipital bones. Humans with CCD show all these features, including severely retarded ossification of the cranial base, strongly suggesting that both intramembranous ossification and endochondral ossification are affected. In addition, CCD patients have multiple supernumerary teeth and delayed tooth eruption. The present report presents 3D reconstructions of computerised tomography (CT) scans of the craniofacial region of a CCD boy examined at both 1 and 7 years of age. The anomalies in craniofacial skeleton and teeth are analysed and compared to the findings of our previous clinical studies an...

Research paper thumbnail of An automated procedure for measurement of prominence transverse velocities

Lecture Notes in Physics

A computer algorithm for measurment of transverse velocities (proper motion) in prominences has b... more A computer algorithm for measurment of transverse velocities (proper motion) in prominences has been developed. We present the method and examples of computed proper motion maps. The method is a modified version of the local cross correlation technique previously applied to granulation images (November 1986, Title et al 1987, November and Simon 1988, November 1988, Darvann 1988, Brandt et al

Research paper thumbnail of Sagittal synostosis: I. Preoperative morphology of the skull

Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery, 2006

The aim of this study was to characterise the preoperative morphology of the skull in sagittal sy... more The aim of this study was to characterise the preoperative morphology of the skull in sagittal synostosis in an objective and quantified way. The shapes of the skulls of 105 patients with isolated premature synostosis of the sagittal suture (SS group) were studied and compared with those of a control group of 72 children with unilateral incomplete cleft lip (UICL). A standardised radiocephalometric technique was used to obtain the images. A modification of a method developed by Kreiborg was used to analyse the radiocephalograms, which included the digitisation of 88 landmarks in the calvaria, skull base, and orbit (42 in the lateral and 46 in the frontal projections), the production of plots of mean shape for each group, and the intergroup comparison of a series of 81 variables (linear distance between selected landmarks, and angles defined by groups of three landmarks). Data from a subgroup of 66 patients aged 5 to 8 months were further compared to age-matched normative data in terms of seven angular and linear calvarial, cranial base and orbital variables. In a comparative analysis of the mean lateral plots, the foreheads of the study group (SS) had a more pronounced anterior slope and were also more convex. The vertex area was located more anteriorly, and was less convex. The occipital curvature was more prominent. Analysis of the mean frontal plots revealed a lack in convexity and lateral projection of the upper parietal regions, as well as a lower location of the line of maximum skull width. Comparison of the mean values of an SS subgroup to age-matched normative data showed a longer (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and narrower skull (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and a greater interorbital distance (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). The cranial base angle, the sella to nasion, and sella to basion lengths did not differ significantly. Sagittal synostosis is characterised by an extensive deformity of the cranial vault, with an essentially normal cranial base. The widened interorbital distance is probably related to compensatory metopic hyperactivity.