Evaluation of the accuracy of automated tooth segmentation of intraoral scans using artificial intelligence-based software packages.

INTRODUCTION: The accuracy of tooth segmentation in intraoral scans is crucial for performing virtual setups and appliance fabrication. Hence, the objective of this study was to estimate and compare the accuracy of automated tooth segmentation generated by the artificial intelligence of dentOne software (DIORCO Co, Ltd, Yongin, South Korea) and Medit Ortho Simulation software (Medit Corp, Seoul, South Korea). METHODS: Twelve maxillary and mandibular pretreatment dental scan sets comprising 286 teeth were collected for this investigation from the archives of the Department of Orthodontics, Faculty of Dentistry, Alexandria University. The scans were imported as standard tessellation language files into both dentOne and Medit Ortho Simulation software. Automatic segmentation was run on each software. The number of successfully segmented teeth vs failed segmentations was recorded to determine the success rate of automated segmentation of each program. Evaluation of success and/or failure was based on the software's identification of the teeth and the quality of the segmentation. The mesiodistal tooth width measurements after segmentation using both tested software programs were compared with those measured on the unsegmented scan using Meshmixer software (Autodesk, San Rafael, Calif). The unsegmented scans served as the reference standard. RESULTS: A total of 288 teeth were examined. Successful identification rates were 99% and 98.3% for Medit and dentOne, respectively. Success rates of segmenting the lingual surfaces of incisors were significantly higher in Medit than in dentOne (93.7% vs 66.7%, respectively; P <0.001). DentOne overestimated the mesiodistal width of canines (0.11 mm, P = 0.032), premolars (0.22 mm, P < 0.001), and molars (0.14 mm, P = 0.043) compared with the reference standard, whereas Medit overestimated the mesiodistal width of premolars only (0.13 mm, P = 0.006). Bland-Altman plots showed that mesiodistal tooth width agreement limits exceeded 0.2 mm between each software and the reference standard. CONCLUSIONS: Both artificial intelligence-segmentation software demonstrated acceptable accuracy in tooth segmentation. There is a need for improvement in segmenting incisor lingual tooth surfaces in dentOne. Both software programs tended to overestimate the mesiodistal widths of segmented teeth, particularly the premolars. Artificial intelligence-segmentation needs to be manually adjusted by the operator to ensure accuracy. However, this still does not solve the problem of proximal surface reconstruction by the software.

Enamel surface roughness following debonding resin clean up using high speed air-turbine and electric handpieces. In vitro study.

BACKGROUND: High speed electric handpieces have recently been growing in popularity among dental professionals. Advantages include smoother surface preparation and increased cutting efficiency. AIM: The primary objective was to compare enamel surface roughness following resin cleanup after bracket debonding using highspeed air turbine versus electric handpiece. The secondary objective was to record the time needed for resin-clean up. METHOD: Forty deidentified freshly extracted human premolars were cleaned and sectioned at the cement-enamel junction. The crowns were embedded in acrylic blocks. Enamel surface roughness parameters (Ra, Rz, Rp and Rv) were measured using a stylus profilometer. Brackets were bonded using a light-cure orthodontic adhesive and stored in distilled water for 24 h. Following bracket debonding, the specimens were randomly divided into 2 groups: First group: resin clean-up was carried out using a 12-fluted carbide bur mounted on a high-speed air turbine; and second group: where an electric handpiece was used. Surface roughness parameters were measured following resin clean up and after polishing using pumice and a rubber cup. Time needed for resin clean-up was recorded. Differences in enamel surface roughness and time between groups were compared using repeated measures ANOVA and independent samples t-test, respectively at P ≤ 0.05. RESULTS: The electric handpiece groups showed significantly higher values for Ra, Rz and Rp both following resin cleanup and polishing. Time taken for resin cleanup was significantly longer for the electric handpiece group. CONCLUSION: Considering both surface roughness and time, electric handpiece do not seem to add greater effectiveness or efficiency to resin cleanup following orthodontic bracket debonding.

Quantifying maxillary anterior tooth movement in digital orthodontics: Does the choice of the superimposition software matter?

BACKGROUND: To compare the agreement between predetermined angular and linear tooth movement measurements processed with three digital model registration software packages. METHODS: Twenty maxillary intraoral pretreatment scans of patients undergoing clear aligner therapy were randomly selected. Digital setups were generated using OrthoAnalyzer Clear Aligner Studio software to serve as the reference standard. Both pretreatment scans and setups were converted to STL files and exported to Geomagic, OrthoAnalyzer-Model Set Compare, and Compare model registration software packages. The amount of tooth movement of the maxillary incisors and canines was calculated in six degrees of freedom. RESULTS: Statistical significance of the obtained results was expressed at P < 0.01 to account for multiple comparisons. The maxillary central incisors showed the highest agreement for torque and rotation as measured by all software programs. Lateral incisors showed the least agreement in linear movements as measured by Geomagic and Compare, and for tip as measured by Geomagic and OrthoAnalyzer. Maxillary canines had the highest agreement for all linear movements as measured by Geomagic and Compare, and tip as measured by Geomagic and OrthoAnalyzer. Geomagic showed excellent agreement for all measurements except for torque, whereas Compare showed excellent agreement only for rotation and linear measurements. OrthoAnalyzer showed moderate agreement for all measurements except for rotation, which showed good agreement. CONCLUSIONS: Maxillary central incisor measurements showed higher agreement compared with measurements of the maxillary lateral incisors and canines. Although none of the software showed poor agreement, Geomagic seemed to have the highest accuracy.

Digital model superimpositions: are different software algorithms equally accurate in quantifying linear tooth movements?

BACKGROUND: To evaluate the accuracy of three different 3D digital model registration software packages for linear tooth movement measurements, with reference to a 3D digital virtual setup (DS). METHODS: Twenty maxillary and mandibular pre-treatment scans of patients undergoing clear aligner therapy were used. Digital Setups were generated from pre-treatment scans using OrthoAnalyzer software. Both the pretreatment digital scans (T1) and Digital Setups (T2) were converted to STL files to be imported to the three studied software packages: Geomagic, OrthoAnalyzer and Compare. Linear changes in tooth positions were calculated for all the registered pairs. RESULTS: The change in tooth position was compared between the calculated tooth movement using each of the registration software packages versus the actual generated tooth movement from the Digital Setups. Continuous data was expressed as mean and standard deviation. Intraclass Correlation Coefficients for agreements between Digital Simulation and each software was used. Intra and Inter-examiner reliabilities were also assessed using Intraclass Correlation Coefficients. Significance of the obtained results was expressed at p ≤ 0.01. Geomagic software showed agreements > 0.90 for maxillary linear tooth movements and between 0.75 and 0.90 for mandibular measurements. OrthoAnalyzer software showed agreements between 0.50 and < 0.75 for maxillary and mandibular measurements. Compare software showed agreements > 0.90 for maxillary and mandibular linear tooth movements, indicating the best consistency. CONCLUSIONS: Compare and Geomagic software packages consistently showed maximum accuracy in measuring the amount of tooth movement in the maxillary arch compared to the reference standard. Compare software showed the highest agreements in the mandibular arch. None of the three studied software packages showed poor agreement with the Digital Setup across all tooth movement measurements. Buccolingual tooth movements showed the highest agreements amongst linear measurements.

TIP, TORQUE & ROTATIONS: How accurately do digital superimposition software packages quantify tooth movement?

BACKGROUND: To investigate the accuracy of three different 3D digital model registration software for tip, torque and rotation measurements, with reference to a 3D digital virtual setup. Twenty maxillary and mandibular pre-treatment scans of patients undergoing clear aligner therapy were used. Digital setups were generated from pre-treatment scans using a tooth movement software. Both the pretreatment digital scans (T1) and digital setups (T2) were converted to STL files to be exported to the 3 studied software that employed: (1) Semiautomatic best fit registration (S-BF), (2) Interactive surface-based registration (I-SB), and (3) Automatic best fit registration (A-BF) respectively. Changes in tip, torque and rotation were calculated for all the registered pairs. RESULTS: The change in tooth position was compared between the calculated tooth movement using each of the registration software packages versus the actual generated tooth movement from the digital setups. Continuous data was expressed as mean and standard deviation. Intra Class Correlation Coefficient for agreement between digital simulation and each software was used. Intra and Inter-examiner reliabilities were also assessed using Intra Class Correlation Coefficient. Significance of the obtained results was expressed at p ≤ 0.01. Semiautomatic best fit registration software showed excellent agreement (> 0.90) for all tooth movements, except for good agreement for torque (0.808). Interactive surface-based registration software showed moderate agreement for all measurements (0.50 and < 0.75), except for good agreement for rotation (0.783). Automatic best fit registration software demonstrated excellent agreement (> 0.90) for rotation, good agreement for tip (0.890) and moderate agreement for torque (0.740). CONCLUSIONS: Overall, semiautomatic best fit registration software consistently showed excellent agreement in superimpositions compared to other software types. Automatic best fit registration software consistently demonstrated better agreement for mandibular superimpositions, compared to others. Accuracy of digital model superimpositions for tooth movements studied in superimposition studies, can be attributed to the algorithm employed for quantification.

Correlation of Vertical Dentoalveolar Heights with Palatal Plane Inclination in Adults with Different Vertical Facial Patterns / Corrélation des hauteurs dento-alvéolaires verticales avec l'inclinaison du plan palatin chez les adultes présentant différentes typologies faciales verticales

Introduction: Various studies showed inconsistent and different results regarding the correlation between open bites and palate planes whether normal or abnormal. This study had for objective to investigate the correlation between dentoalveolar heights and palatal plane inclination in different vertical facial patterns. Materials and Methods: 120 lateral cephalometric radiographs (60 females and 60 males) were selected from the archives of the Faculty of Dentistry, Beirut Arab University. The sample consisted of three equal groups: hypodivergent (SN/MP<27°), normodivergent (SN/MP=27°-37°) and hyperdivergent (SN/MP>37°). The radiographs were digitally traced and cephalometric skeletal and dentoalveolar variables were measured. Statistical analysis was carried out with significance level at p<0.05. Results: The palatal plane inclination showed statistically significant difference between hyperdivergent and both hypodivergent and normodivergent subjects with no statistically significant difference between hypodivergent and normodivergent subjects. A statistically significant difference in the upper anterior dentoalveolar height (UADAH) was found between hypodivergent and both hyperdivergent and normodivergent subjects. No statistically significant difference was found in the other dentoalveolar heights between the different vertical patterns. A negative moderate correlation was only observed between the palatal plane angle and UADAH in the hyperdivergent group. Multiregression analysis showed that the greatest contribution to overbite pooled across all groups other than the skeletal pattern was attributed to UADAH. Conclusion: UADAH seems to influence the overbite depth compared to other dentoalveolar heights. It is possible that UADAH acts as a compensatory factor for palatal plane inclination in hyperdivergent subjects.

Introduction: Diverses études ont montré des résultats incohérents et différents concernant la corrélation entre les béances et les plans du palais, qu'ils soient normaux ou anormaux. Cette étude avait pour objectif d'analyser la corrélation entre les hauteurs dento-alvéolaires et l'inclinaison du plan palatin dans différentes typologies faciales verticales. Matériels et méthodes: Au total, 120 radiographies céphalométriques latérales (60 femmes et 60 hommes) ont été sélectionnées dans les archives de la Faculté de médecine dentaire de l'Université Arabe de Beyrouth. L'échantillon était composé de trois groupes égaux : hypodivergent (SN/PM < 27°), normodivergent (SN/PM = 27° - 37°) et hyperdivergent (SN/PM > 37°). Les radiographies ont été tracées numériquement et les variables squelettiques et dento-alvéolaires céphalométriques ont été mesurées. L'analyse statistique a été réalisée avec un seuil de signification à p < 0,05. Résultats: L'inclinaison du plan palatin a montré une différence statistiquement significative entre les sujets hyperdivergents et les sujets hypodivergents et normodivergents, sans différence statistiquement significative entre les sujets hypodivergents et normodivergents. Une différence statistiquement significative dans la hauteur dento-alvéolaire antérieure supérieure (HDAAS) a été trouvée entre les sujets hypodivergents et les sujets hyperdivergents et normodivergents. Aucune différence statistiquement significative n'a été trouvée dans les autres hauteurs dento-alvéolaires entre les différents modèles verticaux. Une corrélation négative modérée n'a été observée qu'entre l'angle du plan palatin et la HDAAS dans le groupe hyperdivergent. L'analyse multirégression a montré que la plus grande contribution à la supraclusion regroupée dans tous les groupes autres que le schéma squelettique était attribuée à la HDAAS. Conclusion: La HDAAS semble influencer la profondeur de supraclusion par rapport aux autres hauteurs dento-alvéolaires. Il est possible que celle-ci agisse comme un facteur compensateur de l'inclinaison du plan palatin chez les sujets hyperdivergents.

Temporal Arteritis Revealing Antineutrophil Cytoplasmic Antibody-Associated Vasculitides: A Case-Control Study.

OBJECTIVE: Temporal arteritis (TA) is a typical manifestation of giant cell arteritis (GCA). Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) are rarely revealed by TA manifestations, leading to a risk of misdiagnosis of GCA and inappropriate treatments. This study was undertaken to describe the clinical, biologic, and histologic presentations and outcomes in cases of TA revealing AAV (TA-AAV) compared to controls with classic GCA. METHODS: In this retrospective case-control study, the characteristics of patients with TA-AAV were compared to those of control subjects with classic GCA. Log-rank test, with hazard ratios (HRs) and 95% confidence intervals (95% CIs), was used to assess the risk of treatment failure. RESULTS: Fifty patients with TA-AAV (median age 70 years) were included. Thirty-three patients (66%) presented with atypical symptoms of GCA (ear, nose, and throat involvement in 32% of patients, and renal, pulmonary, and neurologic involvement in 26%, 20%, and 16% of patients, respectively). Blood samples were screened for ANCAs at the time of disease onset in 33 patients, and results were positive in 88%, leading to a diagnosis of early TA-AAV in 20 patients. The diagnosis of AAV was delayed a median interval of 15 months in 30 patients. Compared to controls with GCA, patients with TA-AAV were younger (median age 70 years versus 74 years), were more frequently men (48% versus 30%), and had high frequencies of atypical manifestations and higher C-reactive protein levels (median 10.8 mg/dl versus 7.0 mg/dl). In patients with TA-AAV, temporal artery biopsy (TAB) showed fibrinoid necrosis and small branch vasculitis in 23% of patients each, whereas neither of these characteristics was evident in controls with GCA. Treatment failure-free survival was comparable between early TA-AAV cases and GCA controls, whereas those with delayed TA-AAV had a significantly higher risk of treatment failure compared to controls (HR 3.85, 95% CI 1.97-7.51; P < 0.0001). CONCLUSION: TA-AAV should be considered diagnostically in cases of atypical manifestations of GCA, refractoriness to glucocorticoid treatment, or early relapse. Analysis of TAB specimens for the detection of small branch vasculitis and/or fibrinoid necrosis could be useful. Detection of ANCAs should be performed in cases of suspected GCA with atypical clinical features and/or evidence of temporal artery abnormalities on TAB.

Intracranial meningioma as primary presentation for an undiagnosed collision metastatic breast cancer: Case report and literature review.

Intracranial metastasis from breast cancer is a relatively common finding, however, the appearance of breast cancer metastasis in a meningioma is very rare. Several cases of tumor-to-tumor metastasis and collision tumors have been reported previously, with meningioma being implicated as the most common benign intracranial neoplasm to harbour the metastasis. Occasionally, the discovery of a tumor-to-meningioma metastasis may herald the diagnosis of an occult primary malignancy. Careful histopathological assessment of the resected meningioma specimen is pivotal to the management of these patients, as this will alter the treatment plan and prognosis considerably. Intracranial meningioma with collision breast cancer as primary presentation of an undiagnosed metastatic breast cancer is extremely rare. The current study presents a case of intracranial meningioma with collision breast cancer as a primary presentation, and reviews the available evidence for this unusual disease entity.

Prediction of changes due to mandibular autorotation following miniplate-anchored intrusion of maxillary posterior teeth in open bite cases.

BACKGROUND: Prediction of the treatment outcome of various orthodontic procedures is an essential part of treatment planning. Using skeletal anchorage for intrusion of posterior teeth is a relatively novel procedure for the treatment of anterior open bite in long-faced subjects. METHODS: Data were analyzed from lateral cephalometric radiographs of a cohort of 28 open bite adult subjects treated with intrusion of the maxillary posterior segment with zygomatic miniplate anchorage. Mean ratios and regression equations were calculated for selected variables before and after intrusion. RESULTS: Relative to molar intrusion, there was approximately 100% vertical change of the hard and soft tissue mention and 80% horizontal change of the hard and soft tissue pogonion. The overbite deepened two folds with 60% increase in overjet. The lower lip moved forward about 80% of the molar intrusion. Hard tissue pogonion and mention showed the strongest correlations with molar intrusion. There was a general agreement between regression equations and mean ratios at 3 mm molar intrusion. CONCLUSIONS: This study attempted to provide the clinician with a tool to predict the changes in key treatment variables following skeletally anchored maxillary molar intrusion and autorotation of the mandible.

Long-term stability of soft tissue changes in anterior open bite adults treated with zygomatic miniplate-anchored maxillary posterior intrusion.

OBJECTIVES: To evaluate soft tissue changes and their long-term stability in skeletal anterior open bite adults treated by maxillary posterior teeth intrusion using zygomatic miniplates and premolar extractions. MATERIALS AND METHODS: Lateral cephalograms of 26 patients were taken at pretreatment (T1), posttreatment (T2), 1 year posttreatment (T3), and 4 years posttreatment (T4). RESULTS: At the end of treatment, the soft tissue facial height and profile convexity were reduced. The lips increased in length and thickness, with backward movement of the upper lip and forward movement of the lower lip. The total relapse rate ranged from 20.2% to 31.1%. At 4 years posttreatment, 68.9% to 79.8% of the soft tissue treatment effects were stable. The changes in the first year posttreatment accounted for approximately 70% of the total relapse. CONCLUSIONS: Soft tissue changes following maxillary posterior teeth intrusion with zygomatic miniplates and premolar extractions appear to be stable 4 years after treatment.

Orthodontically induced osteocyte apoptosis under different force magnitudes in rats: an immunohistochemical study.

We investigated the effect of different force magnitudes on osteocyte apoptosis in a model of orthodontic tooth movement. Forty-nine male Sprague Dawley rats (7-9 wk of age) were divided into light- and heavy-force groups (n = 21 each group) and a control group (n = 7). A coil spring delivered pressure (either 10-15 g or 20-25 g) to the left maxillary first molar. The rats were sacrificed 1, 3, or 5 d after placement of the appliance. Sections of the maxillary first molars were immunostained for caspase-3. Upon force application, the number of apoptotic osteocytes significantly increased in the pressure side at 1 d and remained the same at 3 d and 5 d. However, there was no significant difference in the number of apoptotic osteocytes between the two force groups. We conclude that osteocyte apoptosis appears to increase under orthodontic loading, reaching a plateau after 1 d. However, osteocyte apoptosis seems to be independent of the magnitude of orthodontic forces tested.

The Great Impostor: Transaminitis Masking the Coinfection of Syphilis and Human Immunodeficiency Virus.

Introduction. The incidence of syphilis continues to rise in the United States over the past 15 years. This disease process is classified into stages and may present with a coinfection of Human Immunodeficiency Virus (HIV). Case Report. We present a case of a 32-year-old African American male who presented with cutaneous manifestations of secondary syphilis and transaminitis. A workup revealed that the transaminitis was secondary to underlying syphilitic hepatitis in the presence of HIV coinfection. The patient had a reactive rapid plasma reagin (RPR) of 1 : 64 TU and reactive Treponema pallidum particle agglutination assay (TPPA). Lab findings showed alkaline phosphate (ALP) of 648 unit/L, aspartate aminotransferase (AST) of 251 unit/L, and alanine aminotransferase (ALT) of 409 unit/L. Conclusion. Syphilitic hepatitis is a recognized entity in the medical literature. It is a manifestation of secondary syphilis and it is more commonly seen in coinfected patients with both syphilis and HIV. Therefore, primary care physicians should keep infectious etiologies (e.g., syphilis and HIV) in the differential diagnosis of patients who present with unexplained liver dysfunction in a cholestatic pattern.

Evaluation of long-term stability of skeletal anterior open bite correction in adults treated with maxillary posterior segment intrusion using zygomatic miniplates.

INTRODUCTION: This study evaluated the long-term stability of maxillary molar intrusion and anterior open-bite correction in adults treated by maxillary posterior teeth intrusion with zygomatic miniplates. METHODS: The sample included 26 skeletal anterior open-bite patients, who had maxillary posterior segment intrusion with zygomatic miniplates. Lateral cephalograms were taken at pretreatment, posttreatment, 1 year posttreatment, and 4 years posttreatment. RESULTS: The mean maxillary molar intrusion was 3.04 mm (P ≤0.01), and the mean bite closure was 6.93 mm (P ≤0.01). The intruded maxillary molars relapsed by 10.20% in the first year after treatment and by 13.37% by 4 years after treatment. Overbite relapsed by 8.19% and 11.18% after 1 year and 4 years posttreatment, respectively. The first year after treatment accounted for 76.29% and 73.2% of the total relapses of molar intrusion and overbite, respectively. The 4-year posttreatment relapse amounts of maxillary molar intrusion and overbite were positively correlated with the amount of pretreatment maxillary molar height and the initial open-bite severity, respectively, but negatively correlated with the amounts of maxillary molar intrusion and open-bite correction gained by treatment. CONCLUSIONS: Molar intrusion with zygomatic miniplates appears to be stable 4 years after treatment.

Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL): assessment of the involved white matter tracts by MRI.

BACKGROUND AND PURPOSE: Leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation (LBSL) is a recently identified autosomal recessive disorder with early onset of symptoms and slowly progressive pyramidal, cerebellar and dorsal column dysfunction. LBSL is characterized by distinct white matter abnormalities and selective involvement of brainstem and spinal cord tracts. The purpose of this study is to assess the imaging features of the involved white matter tracts in cases of LBSL by MRI. PATIENTS AND METHODS: We retrospectively reviewed the imaging features of the selectively involved white matter tracts in sixteen genetically proven cases of leukoencephalopathy with brainstem and spinal cord involvement and elevated brain lactate (LBSL). All patients presented with slowly progressive cerebellar sensory ataxia with spasticity and dorsal column dysfunction. MRI of the brain and spine using 1.5 T machine and proton magnetic resonance spectroscopy (1H MRS) on the abnormal white matter were done to all patients. The MRI and MRS data sets were analyzed according to lesion location, extent, distribution and signal pattern as well as metabolite values and ratios in MRS. Laboratory examinations ruled out classic leukodystrophies. RESULTS: In all cases, MRI showed high signal intensity in T2-weighted and FLAIR images within the cerebral subcortical, periventricular and deep white matter, posterior limbs of internal capsules, centrum semiovale, medulla oblongata, intraparenchymal trajectory of trigeminal nerves and deep cerebellar white matter. In the spine, the signal intensity of the dorsal column and lateral cortico-spinal tracts were altered in all patients. The subcortical U fibers, globi pallidi, thalami, midbrain and transverse pontine fibers were spared in all cases. In 11 cases (68.8%), the signal changes were inhomogeneous and confluent whereas in 5 patients (31.2%), the signal abnormalities were spotty. MRI also showed variable signal abnormalities in the sensory and pyramidal tracts in addition to the brainstem and cerebellar connections. Proton MRS showed consistent elevation of the lactate within the abnormal white matter. CONCLUSION: Distinct MRI findings in the form of selective affection of subcortical and deep white matter tracts of the brain (involving the posterior limb of internal capsules and sparing the subcortical U fibers), dorsal column and lateral cortico-spinal tracts of the spinal cord should lead to the diagnosis of LBSL supported by the presence of lactate peak in 1H MRS. The disease can be confirmed by the analysis of the disease gene DARS2.

Neuronal damage and functional deficits are ameliorated by inhibition of aquaporin and HIF1α after traumatic brain injury (TBI).

The present study, using a rodent model of closed-head diffuse traumatic brain injury (TBI), investigated the role of dysregulated aquaporins (AQP) 4 and 9, as well as hypoxia inducible factor -1α(HIF-1α) on brain edema formation, neuronal injury, and functional deficits. TBI was induced in adult (400-425 g), male Sprague-Dawley rats using a modified Marmarou's head impact-acceleration device (450 g weight dropped from 2m height). Animals in each treatment group were administered intravenous anti-AQP4 or -AQP9 antibodies or 2-Methoxyestradiol (2ME2, an inhibitor of HIF-1α) 30 min after injury. At 24h post-TBI, animals (n=6 each group) were sacrificed to examine the extent of brain edema by water content, as well as protein expression of AQP and HIF-1α by Western immune-blotting. At 48-hours post-TBI, neuronal injury (n=8 each group) was assessed by FluoroJade (FJ) histochemistry. Spatial learning and memory deficits were evaluated by radial arm maze (n=8 each group) up to 21 days post-TBI. Compared to non-injured controls, significant (p<0.05) increases in the expression of AQP4 and -9 were detected in the brains of injured animals. In addition, significant (p<0.05) brain edema after TBI was associated with increases (p <0.05) both in neuronal injury (FJ labeling) and neurobehavioral deficits. Selective inhibition of either AQP4 or -9, or HIF-1α significantly (p<0.05) decreased the expression of the proteins. In addition, inhibition of the AQPs and HIF-1α significantly (p<0.05) ameliorated brain edema, as well as the number of injured neurons in cortical layers II/III and V/VI, striatum and hippocampal regions CA1/CA3. Finally, compared to the non-treated TBI animals, AQP or HIF-1α inhibition significantly (p<0.01) improved neurobehavioral outcomes after TBI. Taken together, the present data supports a causal relation between HIF-AQP mediated cerebral edema, secondary neuronal injury, and tertiary behavioral deficits post-TBI. The data further suggests that upstream modulation of the molecular patho-trajectory effectively ameliorates both neuronal injury and behavioral deficits post-TBI.

Enamel colour changes after debonding using various bonding systems.

OBJECTIVE: To test the possible association between enamel colour alteration and resin tag depth. DESIGN: In vitro laboratory study. SETTING: Department of Orthodontics, Alexandria University, Egypt. MATERIALS AND METHODS: Fifty freshly extracted human premolar teeth were equally divided randomly into a control and four experimental groups. Teeth in group I received only enamel prophylaxis. Teeth in groups II and III were etched with 35% phosphoric acid for 15 and 60 seconds, respectively. Teeth in group IV were conditioned with Prompt L-pop self-etching primer and in group V with Xeno III self-etching primer, according to the manufacturer's instructions. Orthodontic brackets were bonded to the teeth in all experimental groups using Transbond XT composite. Following bracket debonding, finishing and polishing were performed. Enamel colour was evaluated spectrophotometrically at baseline and then after debonding, with the corresponding colour differences ΔE calculated. Resin tags lengths were measured on sectioned teeth in each experimental group under scanning electron microscope. RESULTS: All experimental groups showed clinically perceivable colour change after debonding and finishing as all values were exceeded the clinical colour detection threshold of ΔE = 3.7 units. Significant differences (P<0.05) in resin tag length were found in all experimental groups. Significant moderate correlation was found between colour change and resin tags length when all teeth were combined and tested, irrespective of group. CONCLUSIONS: Moderate evidence exists that shorter resin tag penetration produces less change in enamel colour following clean-up and polishing. Self-etch primers produce less resin penetration and these systems may produce less iatrogenic colour change in enamel following orthodontic treatment.

Tooth transposition: a review and clinical considerations for treatment.

This article reviews the literature on tooth transposition. Several cases with various types and combinations of tooth transposition are presented and treatment management and options are discussed. Indications, advantages, and disadvantages of correcting versus maintaining tooth order are shown.