Dimensional changes of endodontic sealers-An in vitro model simulating a clinical extrusion scenario during 18 months.

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. All teeth were immersed in a physiologic solution for up to 18 months. Blinded 3D surface scans (resolution: ~10 µm) and digital radiographs of the teeth were obtained at baseline (immediately after obturation); and then after 1 week, and at 1, 3, and 18 months. For blinded assessment of sealer dimensional change, 3D models and radiographs were superimposed using specific software. Volumetric differences, root mean square (RMS), and area change from subtraction radiography measured at each period within each sealer group were thereafter calculated. Repeated measures analyses were done with Bonferroni adjustment for multiple comparisons; standard errors, p values, and 95% confidence intervals (CI) were reported. RESULTS: Analyses of the volumetric data confirmed significant, progressive material loss for Apexit Plus when compared to the other investigated sealers or the control group (p ≤ 0.02). Immersion period significantly influenced the volumetric dimensional changes of Apexit Plus already after 1 month (p < 0.01). For TubliSeal EW, the effect of the immersion period on the dimensional changes was noted after immersion for 3 months (p ≤ 0.02), while for BioRoot RCS this was evident only at 18 months (p < 0.01). Same trends were noted for the RMS data, whereas progressive dimensional changes using subtraction radiography only revealed significant changes for Apexit Plus (p = 0.01). CONCLUSIONS: The largest dimensional changes were shown by Apexit Plus, followed by Tubliseal EWT and BioRoot RCS. AH Plus remained stable throughout 18 months.

Facial Asymmetry in Nonsyndromic and Muenke Syndrome-Associated Unicoronal Synostosis: A 3-Dimensional Study Based on Facial Surfaces Extracted From CT Scans.

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: 0.6 years; range: 0.1-1.4 years) were included in the study (NS-UCS = 14; MS-UCS = 7). From presurgical computed tomography scans, facial surfaces were constructed for analysis. A landmark guided atlas was deformed to match each patient's surface, obtaining spatially detailed left-right point correspondence. Facial asymmetry was calculated in each surface point across the face, as the length (mm) of an asymmetry vector, with its Cartesian components providing 3 directions. Mean FA was calculated for the full face, and the forehead, eye, nose, cheek, mouth, and chin regions. RESULTS: For the full face, a significant difference of 2.4 mm (P = .001) was calculated between the 2 groups, predominately in the transverse direction (1.5 mm; P < .001). The forehead and chin regions presented with the largest significant difference, 3.5 mm (P = .002) and 3.2 mm (P < .001), respectively; followed by the eye (2.4 mm; P = .004), cheek (2.2 mm; P = .004), nose (1.7 mm; P = .001), and mouth (1.4 mm; P = .009) regions. The transverse direction presented with the largest significant difference in the forehead, chin, mouth, and nose regions, the sagittal direction in the cheek region, and the vertical direction in the eye region. CONCLUSIONS: Muenke syndrome-associated unicoronal synostosis presented with significantly larger FA in all regions compared to NS-UCS. The largest significant differences were found in the forehead and chin regions, predominantly in the transverse direction.

Delayed maturation and reduced crown width of the permanent first mandibular molar in all subgroups of cleft lip and palate.

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 (M1inf ) 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. SETTING AND SAMPLE POPULATION: A population-based consecutive longitudinal sample of 224 children with clefts: 183 with CLP (66 with complete [47 unilateral, 19 bilateral], 117 with incomplete [70 unilateral, 47 bilateral], and 41 with unilateral incomplete cleft lip (controls), was examined pre- and post-lip closure (at 2 and 22 months of age). MATERIAL AND METHODS: In lateral cephalometric X-rays (obtained as part of a standard treatment protocol), M1inf follicle maturation and follicle/crown width were assessed. Mantel-Haenszel test and Pearson's correlation coefficient R were used to describe relationships. Differences between group means were tested using Wilcoxon rank sum test. Significance level was set to 5%. RESULTS: Follicle maturation was significantly delayed in all groups with CLP compared to that in controls (P < .01). Follicle and crown width were significantly reduced in all CLP groups compared with those in controls (P < .01). Sex did not influence these variables. CONCLUSION: Delayed follicle maturation and decreased follicle/crown/tooth size were found to be part of the congenital traits characterizing individuals with all types of CLP and not a result of surgical iatrogenesis.

Phenotypic variability in Muenke syndrome-observations from five Danish families.

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. The purpose of this report is to increase awareness of the high phenotypic variability seen in Muenke syndrome. DNA testing for the p.Pro250Arg mutation is routinely performed in Denmark, in children presenting with isolated coronal synostosis. Verified diagnosis entails detailed family history, drawing of family pedigree, DNA testing of the parents, genetic counseling, skull radiographs, clinical photographs, and follow-up. Sixteen individuals from 5 Danish families with Muenke syndrome are presented. Large phenotypic variation was seen both within and across families. The most striking observations were that 6/16 (38%) cases did not have craniosynostosis and one individual presented with a normal phenotype. In addition, 3 unrelated cases had incomplete cleft palate, submucous cleft palate, and bifid uvula, respectively. There is strong evidence for reduced penetrance of the craniosynostosis trait in Muenke syndrome. We argue that many studies on Muenke syndrome have been influenced by ascertainment bias in regard to craniosynostosis. In addition, it is suggested that oral clefting might be part of the clinical spectrum seen in Muenke syndrome.

Three-dimensional assessment of facial morphology in children and adolescents with juvenile idiopathic arthritis and moderate to severe TMJ involvement using 3D surface scans.

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. The means and variabilities of facial morphology in groups 2 and 3 were assessed and compared with those of group 1 in three dimensions, respectively. RESULTS: Group 2 (unilateral group) exhibited a more retruded and wider chin, shorter mandibular height, and more prominent cheek (2, 2, 5, and 2 mm, on average, respectively) on the affected side and a more retruded and narrower chin and more prominent malar region (4, 3, and 2 mm, on average, respectively) on the unaffected side compared with group 1 (no involvement group) (p < 0.05). Group 3 (bilateral group) exhibited a more retruded chin, shorter mandibular height, more prominent upper cheeks, and narrower perioral region (5, 5, 3, and 2 mm, respectively) compared with group 1 (no involvement group) (p < 0.05). CONCLUSIONS: In JIA subjects with moderate to severe unilateral or bilateral TMJ involvement, the affected side(s) revealed similar facial dysmorphology with reduced mandibular height, chin retrusion, and prominent upper cheek. CLINICAL RELEVANCE: Three-dimensional surface scans can be a non-ionizing indicator of signs of TMJ involvement in JIA subjects.

Dynamic soft tissue changes in the orbit after a blowout fracture.

Background/objectives: 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). Materials and methods: Patients with a blowout fracture underwent an MRI scan within 72 h after the trauma and again after 10-14 days. Measurements of EOMS and fat tissue on the fractured orbit were compared to the unfractured orbit. Results: Eighteen patients were included. Measurements showed significantly larger volume, cross-sectional area and MGV of the EOM closest to the fracture compared to the same muscle in the unfractured orbit. This significance disappeared for some parameters on the second scan. The volume of herniated orbital contents was significantly smaller on the second scan than on the first. Conclusions and significance: Based on the first longitudinal MRI study on patients with blowout fractures, our results indicate post-traumatic oedema in the intraorbital soft tissue which subsides between scans. A watchful waiting period is recommended in the initial post-traumatic days in patients without muscle entrapment.

Spatially Detailed 3D Quantification of Improved Facial Symmetry After Surgery in Children With Unicoronal Synostosis.

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. Preoperative computed tomography scans and postoperative 3dMD surfaces were available for measurements. A control group of healthy children matched for age and sex was employed. MAIN OUTCOME MEASURES: Pre- and postsurgical facial asymmetry was analyzed using a computerized method capable of objective and spatially detailed quantification in 3-dimension (transverse, vertical, and sagittal directions). Asymmetry was evaluated in the facial region and 6 subregions (forehead, mouth, eyes, nose, cheek, and chin). RESULTS: The largest significant improvement was seen in the sagittal direction of the facial (1.9 mm), forehead (2.0 mm), and cheek (3.4 mm) regions. Small but significant improvements were also seen in the mouth, chin, and eye regions. No significant improvement was seen in the nose region. Significant correlations were found between the pre- and postsurgically calculated facial asymmetry and between calculated asymmetry and clinical validation scores. CONCLUSIONS: All patients presented with improved facial symmetry after surgery and the improvements were visually recognizable. However, only 1 (9.1%) of the 11 patients reached a level of facial asymmetry as low as that seen in the control group. The best outcome was, in general, seen in cases with mild facial asymmetry presurgically.

Parental age in relation to the severity of cleft lip and/or palate.

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. The groups were subdivided according to the extent/severity of cleft. Unilateral clefts were divided according to left/right sidedness. Logistic regression was used to analyse the association between parental age and risk of severe cleft separately for CL ± P and CP, as well as between parental age and risk of right-sided cleft. RESULTS: In CL ± P, the risk of a complete cleft in the offspring increases with maternal age when the paternal age exceeds approximately 29 years. Moreover, the risk is higher when both parents are old than when both parents are young. In CP, no statistically significant results were identified. However, there were clear trends that indicated a similar pattern as that for CL ± P. No association was identified between increased parental age and the sidedness of clefts. CONCLUSIONS: Parental age seems to contribute to cleft severity, as older parents showed a higher risk of having offspring with a complete cleft than younger parents.

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

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, almond-shaped 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.

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

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. Agreement in results between CT and MRI as well as inter- and intraexaminer errors were evaluated by statistical and three-dimensional analysis. RESULTS: 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% percentile Hausdorff Distance (HD) < 2 mm = acceptable agreement]. The results were replicable and not influenced by systematic errors. CONCLUSION: We found a high accuracy and precision of manual segmentation of the maxillary sinus in MR images. The largest mean errors were found close to the orbit and the teeth. Advances in knowledge: MRI can be used for 3D models of the paranasal sinuses with equally good results as CT and allows longitudinal follow-up of sinus development.

Quantifying Normal Craniofacial Form and Baseline Craniofacial Asymmetry in the Pediatric Population.

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. METHODS: After institutional review board approval, normal, healthy children (n = 533) with no known craniofacial abnormalities were recruited at well-child visits to undergo full head stereophotogrammetric imaging. The children's ages ranged from 0 to 18 years. A symmetric three-dimensional template was registered and scaled to each individual scan using 25 manually placed landmarks. The template was deformed to each subject's three-dimensional scan using a thin-plate spline algorithm and closest point matching. Age-based normal facial models were derived. Mean facial asymmetry and statistical characteristics of the population were calculated. RESULTS: The mean head asymmetry across all pediatric subjects was 1.5 ± 0.5 mm (range, 0.46 to 4.78 mm), and the mean facial asymmetry was 1.2 ± 0.6 mm (range, 0.4 to 5.4 mm). There were no significant differences in the mean head or facial asymmetry with age, sex, or race. CONCLUSIONS: Understanding the "normal" form and baseline distribution of asymmetry is an important anthropomorphic foundation. The authors present a method to quantify normal craniofacial form and baseline asymmetry in a large pediatric sample. The authors found that the normal pediatric craniofacial form is asymmetric, and does not change in magnitude with age, sex, or race.

An Applied Anatomical Study of the Ethmoidal Arteries: Computed Tomographic and Direct Measurements in Human Cadavers.

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. Preoperative measurements on CT images may provide more precise distances than absolute rules and thus lead to safer orbital surgery. The authors hypothesize that the distances to the ethmoidal arteries and the length of the medial wall are positively correlated and that measurements of the distances from the posterior lacrimal crest (PLC) on CT images are feasible with a low intra- and interobserver variability.Fifty intact orbits from 25 Caucasian cadavers were exenterated and examined. In additional, high-resolution CT scans of 48 orbits from 24 other Caucasian nonexenterated cadavers were examined. Distances were measured from 4 different anterior landmarks to the AEF and PEF and the OC.Distances from the most anterior landmarks to the arteries were positively correlated with the length of the medial wall. Measurements of the distances from the PLC to the ethmoidal arteries on CT images were feasible with a low intra- and interobserver variability. In conclusion, iatrogenic damage to the ethmoidal arteries in the orbit may be best avoided by using CT measurements in presurgical planning.

Accuracy and reproducibility of the DAVID SLS-2 scanner in three-dimensional facial imaging.

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. A precision of ≤1 mm was considered clinically significant. RESULTS: The mannequin face model was reproduced with no significant errors in the SLS-2 compared to the 3dMDtrio, with normally distributed data (mean = 0.002 mm; SD = 0.01 mm). In live subjects, the forehead, midface, chin and general face region showed mean errors and SD <0.24 mm and <1 mm, respectively. In the neck area, the data were not found to be normally distributed (mean = -1.6 mm; SD = 2.1 mm). CONCLUSION: Structured light scanning may be used for acquiring 3D face scans in live subjects in a radiation-free and reproducible manner, provided that the head of the subject is positioned in the same posture for each scan. Special care is recommended in positioning the head in the sagittal plane during scanning.

Prenatal diagnosis of autosomal recessive Robinow syndrome using 3D ultrasound.

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.

Facial morphology in children and adolescents with juvenile idiopathic arthritis and moderate to severe temporomandibular joint involvement.

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. 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. RESULTS: 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 <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 < r < 0.9; P <0.001). CONCLUSIONS: 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.

Facial Asymmetry in Children with Unicoronal Synostosis Who Have Undergone Craniofacial Reconstruction in Infancy.

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. Methodological study. SETTING: Primary care center. PATIENTS/PARTICIPANTS: Twenty-two children with UCS were selected after review of records. INCLUSION CRITERIA: isolated UCS; surgically treated for UCS within the first 19 months of life, without secondary reconstruction; and DNA analysis for the Muenke mutation. An age- and sex-matched control group was employed. INTERVENTIONS: The UCS group had undergone bilateral craniotomy of the frontal bone with unilateral supraorbital rim advancement. MAIN OUTCOME MEASURE(S): Using 3D surface scanning, a detailed map of 3D asymmetry presenting the amount of asymmetry in the sagittal, vertical, and transverse directions was calculated for six facial subregions. RESULTS: The facial asymmetry in the UCS group was significantly larger than in the control group for all regions, to the largest extent in the sagittal direction (level of significance: 5%). The regions with the most pronounced asymmetry were cheeks (mean: 5.45 mm; SD: 1.83 mm), forehead (mean: 5.00 mm; SD: 1.57 mm), and eyes (mean: 4.26 mm; SD: 1.44 mm). CONCLUSIONS: Ninety percent of the UCS patients in the study had significant facial asymmetry throughout the facial area. The study demonstrates a methodology of facial asymmetry quantification well suited for soft-tissue surgical outcome evaluations and long-term follow-up studies in patients with craniofacial anomalies.

Early postnatal development of the mandibular permanent first molar in infants with isolated cleft palate.

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. Cephalometric X-rays were available for 2 and 22 months old children with clefts (64 children with ICP, and a control group of 38 children with unilateral incomplete cleft lip). The width of the follicle and the crown of M1(inf), and the maturation of M1(inf) were assessed. Intra-observer error was acceptable. RESULTS: M1(inf) maturation was delayed in children with ICP at both 2 and 22 months of age. The mesiodistal diameter of the crown of M1(inf) in the ICP group was reduced. Thus, the two hypotheses could not be refuted. CONCLUSIONS: Children with ICP showed smaller dimensions of the M1(inf) , and in addition, the maturation of M1(inf) was delayed.

Three-dimensional analysis of the pulp cavity on surface models of molar teeth, using X-ray micro-computed tomography.

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. In order to relate the measurements to changes over time the size of the pulp chambers was classified in two well-defined groups. RESULTS: The mineral deposits were more evenly distributed in small pulp chambers than in large, but complete root canal calcification was never observed. No difference was observed in the material with respect to the presence of intra-radicular connections. In upper molars, a second mesiobuccal canal (mb(2)) frequency of 91% was found. The difference in length between the first mesiobuccal canal (mb(1)) and mb(2) was <1 mm. The number of root canals could be related to the number of root cones. CONCLUSION: In summary, three-dimensional surface models were made with a high precision; an increased accumulation of mineral deposits was noted in molars with small pulp chambers and combined with the consistent pattern of intra-radicular connections, the potential endodontic treatment complexity is underlined in such cases. Finally, an improved understanding of root canal prevalence was reached, when merging well-defined definitions on root morphology and clinical classification systems.

3D analysis of facial asymmetry in subjects with juvenile idiopathic arthritis.

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. Panoramic X-rays were rated for severity of TMJ involvement. For each individual, a spatially detailed facial asymmetry map was created from the 3D photograph. Mean and variability of asymmetry were calculated for each of the three groups and compared. RESULTS: Distinct patterns of asymmetry were found in Groups 1 and 2. With mean asymmetry values up to 3.5 mm, Group 1 exhibited a significantly greater amount of asymmetry in a broad band along the lower jaw extending from the region of the condyle to the chin than Group 2. The mean facial asymmetry (1 S.D.) for each JIA group was 2.3 (0.9), 2.0 (0.7), 1.7 (0.5) mm for Groups 1, 2 and 3, respectively. CONCLUSION: JIA subjects with TMJ involvement displayed patterns of facial asymmetry consistent with the destruction of the condylar growth centre, leading to mandibular asymmetry with displacement of the bony chin. Facial asymmetry quantification was found to be an effective method for assessing both the amount and the localization and spatial extent of asymmetry in all 3Ds.