Publications by authors named "Tron A Darvann"

Objectives: To examine the dimensional changes of endodontic sealers during 18 months using three-dimensional (3D) surface scanning and subtraction radiography in a novel in vitro sealer-extrusion model.

Material And Methods: Fifty endodontically instrumented acrylic teeth were randomly allocated to five groups (n = 10) filled with Apexit Plus, AH Plus, BioRoot RCS, TubliSeal EWT, and gutta-percha (control). Freshly mixed sealers were intentionally extruded during obturation.

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Objective: To quantify soft tissue facial asymmetry (FA) in children with nonsyndromic and Muenke syndrome-associated unicoronal synostosis (NS-UCS and MS-UCS), hypothesizing that MS-UCS presents with significantly larger FA than NS-UCS.

Design: Retrospective cohort study.

Patients And Methods: Twenty-one children (mean age: 0.

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Objectives: Surgical closure of the cleft damages nerves and blood supply in the area and may possibly negatively influence dental development in children with cleft lip and palate (CLP). Previous studies of the permanent first mandibular molar (M1 ) in children with unilateral complete CLP found delayed maturation and decreased follicle/crown width before any surgical interventions. This study aimed to investigate if these findings are representative for the total population of individuals born with CLP.

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Muenke syndrome is a craniosynostosis syndrome associated with the p.Pro250Arg mutation in FGFR3. An increasing number of individuals with this mutation are reported to not have craniosynostosis.

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The intraorbital contents are thought to be affected by oedema in the days following a blowout fracture. We posit that this oedema can be detected by Magnetic resonance imaging (MRI) as changes in muscle volume, in muscle cross-sectional area, and in the MRI parameter 'mean grey value' (MGV) of the orbital fat and extraocular muscles (EOMs). Patients with a blowout fracture underwent an MRI scan within 72 h after the trauma and again after 10-14 days.

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Objective: This study aims to (1) assess the facial morphology in juvenile idiopathic arthritis (JIA) subjects with moderate to severe temporomandibular joint (TMJ) involvement using 3D surface scans and (2) compare the facial morphology in these subjects to that in JIA subjects without TMJ involvement.

Methods: Sixty JIA subjects were included and grouped as follows: group 1 (no involvement group), JIA without TMJ involvement; Group 2 (unilateral group), JIA with moderate to severe unilateral TMJ involvement; and group 3 (bilateral group), JIA with bilateral TMJ involvement. Standard orientation of all surfaces was accomplished.

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Objective: To assess improvement of soft-tissue facial symmetry in children surgically treated for unicoronal synostosis (UCS) in infancy, to correlate pre- and postsurgical facial asymmetry and to evaluate whether the improvement was visually recognizable.

Design: Case-controlled follow-up.

Patients/settings: Eleven Danish children diagnosed with UCS were included, 3 of whom had tested positive for Muenke mutation.

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Objective: To investigate parental age in relation to the severity of cleft diagnosis in a population-based consecutive sample of individuals with clefts.

Setting/sample: Retrospective, consecutive.

Material/methods: The sample comprised 545 consecutive cases with nonsyndromic clefts (437 individuals with cleft lip with/without cleft palate [CL ± P] and 106 individuals with isolated cleft palate [CP]) and parental ages recorded.

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Background: Restoring craniofacial symmetry is an important objective in the treatment of many craniofacial conditions. Normal form has been measured using anthropometry, cephalometry, and photography, yet all of these modalities have drawbacks. In this study, the authors define normal pediatric craniofacial form and craniofacial asymmetry using stereophotogrammetric images, which capture a densely sampled set of points on the form.

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Objective: 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.

Methods: 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.

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Computed tomography (CT) images have been used in very few studies on distances to the ethmoidal arteries in the orbit. Most other studies have included direct measurements on cadavers and frequently quote the 24-12-6 mm rule to describe distances from the anterior lacrimal crest to the anterior and posterior ethmoidal foramina (AEF and PEF), optic canal (OC), respectively. However, the large interindividual variation of distances renders absolute values less applicable in a clinical setting.

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Purpose: A prospective study was performed to test the accuracy and reproducibility of the DAVID-SLS-2 scanner (SLS-2) [DAVID Vision Systems GmbH], compared to the validated 3dMDtrio scanner (3dMD) [3dMD, LLC, Atlanta, GA, USA].

Materials And Methods: The accuracy of the SLS-2 was determined through multiple scans of a mannequin face model using both scanners. The reproducibility of a protocol for achieving consistent three-dimensional (3D) face scans in live subjects was carried out using the SLS-2.

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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.

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Introduction: 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.

Methods: 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.

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Objective: Quantitatively assess 3D spatially detailed soft-tissue facial asymmetry in children who had undergone craniofacial reconstruction for Unicoronal Synostosis (UCS), and compare the facial asymmetry to control patients. It was hypothesized that there would be no significant differences in the facial asymmetry between the groups.

Design: Clinical, retrospective follow-up study.

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Background: Based on measurements on dental casts, smaller permanent teeth in children with cleft palate have previously been reported in the literature; however, the early maturation of teeth and the size of the follicles and crowns have not been investigated.

Hypothesis: The maturation of the mandibular permanent first molar (M1(inf)) is delayed, and the mesiodistal diameters of the follicle and crown of M1(inf), respectively, are reduced in children with isolated cleft palate (ICP).

Design: Retrospective, longitudinal.

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Aim: The purpose of this study was to investigate the scanning and segmentation precision of surface models of molars for the detection of small volumes, such as the reduced pulp cavity; formation of mineral deposits; detection of narrow root canals and to improve the clinical and morphological understanding of the number of root canals and their configuration.

Methods: Eighteen human molars were scanned using X-ray micro-computed tomography. The reconstruction of the surface models had a precision of <1 voxel, using three-dimensional software and quantitative color mapping.

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Objective: To investigate and compare facial asymmetry in subjects with JIA with unilateral, bilateral or no TM joint (TMJ) involvement.

Methods: Eighty-one subjects with JIA: 22 with unilateral TMJ involvement (Group 1), 15 with bilateral TMJ involvement (Group 2) and 44 with no TMJ involvement (Group 3). Panoramic X-rays and three-dimensional (3D) photographs (surface scans) were obtained for all subjects.

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Background And Purpose: Orthotic helmets and active repositioning are the most common treatments for deformational plagiocephaly (DP). Existing evidence is not sufficient to objectively inform decisions between these options. A three-dimensional (3D), whole-head asymmetry analysis was used to rigorously compare outcomes of these 2 treatment methods.

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Objective: To present normative data on prenatal mandibular morphology and growth.

Material And Methods: Fifty-four normal fetuses (Danish Caucasian) were included in the study (gestational age: 11-26 weeks). Fetuses were scanned using a GE Voluson 730 Expert 3D scanner.

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This paper introduces a novel approach to quantify asymmetry in each point of a surface. The measure is based on analysing displacement vectors resulting from nonrigid image registration. A symmetric atlas, generated from control subjects is registered to a given subject image.

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Objective: To investigate the relationship between corresponding two-dimensional and three-dimensional measurements on maxillary plaster casts taken from photographs and three-dimensional surface scans, respectively.

Materials And Methods: Corresponding two-dimensional and three-dimensional measurements of selected linear distances, curve lengths, and (surface) areas were carried out on maxillary plaster casts from individuals with unilateral or bilateral cleft lip and palate. The relationship between two-dimensional and three-dimensional measurements was investigated using linear regression.

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Crouzon syndrome is characterized by premature fusion of sutures and synchondroses. Recently, the first mouse model of the syndrome was generated, having the mutation Cys342Tyr in Fgfr2c, equivalent to the most common human Crouzon/Pfeiffer syndrome mutation. In this study, a set of micro-computed tomography (CT) scannings of the skulls of wild-type mice and Crouzon mice were analysed with respect to the dysmorphology caused by Crouzon syndrome.

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The purpose of this study was to test whether the severity of the cranial phenotype in Muenke syndrome infants with unicoronal synostosis is greater than in infants with nonsyndromic unicoronal synostosis. A total of 23 infants were included in the study. All infants included in the study had a computed tomography (CT)-verified synostosis of the coronal suture.

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