The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform

Ai Hong - One of the best experts on this subject based on the ideXlab platform.

  • Clinical Study on Soft Tissue Changes Caused by Twin-Block Appliance in Patients with Mandibular Retrognathia
    Chinese Journal of General Practice, 2009
    Co-Authors: Ai Hong
    Abstract:

    Objective To investigate the soft tissue changes caused by Twin-Block appliance which were used to treated Angle's class Ⅱ division 1 malocclusion with mandibular Retrognathia.Methods 20 patients in growth stage with Angle's Class Ⅱ division 1 malocclusion and mandibular Retrognathia were investigated.Cephalometric analysis was carried out before and after the treatment of Twin-Block appliance.Data were analyzed by SPSS11.0 system using paired t-test.Results There were significant increases in FH-H'Pg' angle(P0.01)and Sn-H(P0.05),while 1-LZ and H-H'Pg' angle and Li-H and Si-H decreased(P0.05).Conclusion Twin-Block appliance can reset the mandible forward on Angle's Class Ⅱ division 1 malocclusion patients with mandibular Retrognathia,while the thickness of patient's lips decreased and it contributed to a better profile.

Karl Oliver Kagan - One of the best experts on this subject based on the ideXlab platform.

  • Frontal space distance in facial clefts and Retrognathia at 11-13 weeks' gestation
    Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2016
    Co-Authors: M Hoopmann, Caterina M. Bilardo, Jiri Sonek, Tilman Esser, Philipp Wagner, Harald Abele, Karl Oliver Kagan
    Abstract:

    Objective To examine the frontal space (FS) distance in first-trimester fetuses with bilateral, unilateral or median cleft lip and palate and in those with Retrognathia. Methods This was a retrospective study using stored two-dimensional ultrasound images of fetal profiles that were recorded at the time of the nuchal translucency (NT) scan at three prenatal medical centers. Images of 300 normal fetuses and 53 fetuses with facial defects were obtained. To measure the FS distance, a line was drawn between the anterior edge of the mental protuberance of the mandible and anterior edge of the maxilla (MM line) and extended upwards in front of the forehead. The perpendicular distance (FS distance) between the MM line and the skin at the point of largest excursion of the fetal forehead was measured. In cases in which the MM line was located anteriorly to the forehead, the distance was measured in the same fashion but was multiplied by −1. Two operators measured the FS distance twice, independently of each other. FS distances were transformed into Z-scores based on the linear relationship with crown–rump length (CRL) in normal fetuses. The distribution of FS distances in fetuses with bilateral, unilateral or median cleft lip and palate and those with Retrognathia were compared with that in the normal group using Student's t-test. Results A search of the centers' databases identified 53 abnormal cases including 20, nine and eight with a bilateral, unilateral and median cleft lip and palate, respectively, and 16 cases of Retrognathia. In fetuses with bilateral, unilateral and median clefts and those with Retrognathia, median delta NT was 1.00 mm, 0.37 mm, 4.00 mm and 0.26 mm, respectively. Among these affected groups, 12 (60.0%), six (66.7%), two (25.0%) and eight (50.0%) fetuses had an abnormal karyotype. In the normal population, FS distance was dependent on CRL measurement (FS = 6.62 − (0.08 × CRL); r = –0.539; P 

  • frontal space distance in facial clefts and Retrognathia at 11 13 weeks gestation
    Ultrasound in Obstetrics & Gynecology, 2016
    Co-Authors: M Hoopmann, Jiri Sonek, Tilman Esser, C M Bilardo, Philipp Wagner, Harald Abele, Karl Oliver Kagan
    Abstract:

    Objective To examine the frontal space (FS) distance in first-trimester fetuses with bilateral, unilateral or median cleft lip and palate and in those with Retrognathia. Methods This was a retrospective study using stored two-dimensional ultrasound images of fetal profiles that were recorded at the time of the nuchal translucency (NT) scan at three prenatal medical centers. Images of 300 normal fetuses and 53 fetuses with facial defects were obtained. To measure the FS distance, a line was drawn between the anterior edge of the mental protuberance of the mandible and anterior edge of the maxilla (MM line) and extended upwards in front of the forehead. The perpendicular distance (FS distance) between the MM line and the skin at the point of largest excursion of the fetal forehead was measured. In cases in which the MM line was located anteriorly to the forehead, the distance was measured in the same fashion but was multiplied by −1. Two operators measured the FS distance twice, independently of each other. FS distances were transformed into Z-scores based on the linear relationship with crown–rump length (CRL) in normal fetuses. The distribution of FS distances in fetuses with bilateral, unilateral or median cleft lip and palate and those with Retrognathia were compared with that in the normal group using Student's t-test. Results A search of the centers' databases identified 53 abnormal cases including 20, nine and eight with a bilateral, unilateral and median cleft lip and palate, respectively, and 16 cases of Retrognathia. In fetuses with bilateral, unilateral and median clefts and those with Retrognathia, median delta NT was 1.00 mm, 0.37 mm, 4.00 mm and 0.26 mm, respectively. Among these affected groups, 12 (60.0%), six (66.7%), two (25.0%) and eight (50.0%) fetuses had an abnormal karyotype. In the normal population, FS distance was dependent on CRL measurement (FS = 6.62 − (0.08 × CRL); r = –0.539; P < 0.0001). In fetuses with a bilateral and median cleft and in those with Retrognathia, FS distance was significantly different from that in the normal population (all P < 0.0001), however, the difference was not significant in fetuses with unilateral clefts (P = 0.103). The respective Z-scores of FS distance for fetuses with bilateral, unilateral and median clefts and Retrognathia were −9.7 ± 2.0, −3.1 ± 5.1, 8.2 ± 3.4 and −7.3 ± 2.3. Measurements were ≥ 99th and ≤ 1st centiles in all but one (98.1%) case. Conclusion The FS distance appears to be a helpful tool in the detection of facial clefts at 11–13 weeks' gestation. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

E Vicau - One of the best experts on this subject based on the ideXlab platform.

  • the fetal mandible a 2d and 3d sonographic approach to the diagnosis of Retrognathia and micrognathia
    Ultrasound in Obstetrics & Gynecology, 2002
    Co-Authors: D Rotte, J M Levailla, H Martinez, Ducoule Le H Pointe, E Vicau
    Abstract:

    Objective To define parameters that enable the objective diagnosis of anomalies of the position and/or size of the fetal mandible in utero. Design Fetuses at 18–28 gestational weeks were examined by two- and three-dimensional ultrasound. The study included normal fetuses and fetuses with syndromes associated with known mandible pathology: Pierre Robin sequence or complex (n = 8); hemifacial microsomia (Treacher–Collins syndrome, n = 3); postaxial acrofacial dysostosis (n = 1). Fetuses with Down syndrome (n = 8) and cleft lip and palate without Pierre Robin sequence or complex (n = 18) were also studied. Retrognathia was assessed through the measurement of the inferior facial angle, defined on a mid-sagittal view, by the crossing of: 1) the line orthogonal to the vertical part of the forehead at the level of the synostosis of the nasal bones (reference line); 2) the line joining the tip of the mentum and the anterior border of the more protruding lip (profile line). Micrognathia was assessed through the calculation of the mandible width/maxilla width ratio on axial views obtained at the alveolar level. Mandible and maxilla widths were measured 10 mm posteriorly to the anterior osteous border. Results In normal fetuses, the inferior facial angle was constant over the time span studied. The mean (standard deviation) value of the inferior facial angle was 65.5 (8.13)°. Consequently, an inferior facial angle value below 49.2° (mean—2 standard deviations) defined retrognathism. All the fetuses with syndromes associated with mandible pathology had inferior facial angle values below the cut-off value. Using 49.2° or the rounded-up value of 50° as a cut-off point, the inferior facial angle had a sensitivity of 1.0, a specificity of 0.989, a positive predictive value of 0.750 and a negative predictive value of 1.0 to predict Retrognathia. In normal fetuses, the mandible width/maxilla width ratio was constant over the time interval studied. The mean (standard deviation) value was 1.017 (0.116). Consequently, a mandible width/maxilla width ratio <0.785 defined micrognathism. Mandible width/maxilla width ratio values were below this cut-off point in eight and in the normal range in four fetuses with syndromes associated with mandible pathology. Conclusions Retrognathia and micrognathia are conditions that can be separately assessed. The use of inferior facial angle and mandible width/maxilla width ratio should help sonographic recognition and characterization of fetal retrognathic and micrognathic mandibles in utero. Copyright © 2002 ISUOG

M Hoopmann - One of the best experts on this subject based on the ideXlab platform.

  • Frontal space distance in facial clefts and Retrognathia at 11-13 weeks' gestation
    Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2016
    Co-Authors: M Hoopmann, Caterina M. Bilardo, Jiri Sonek, Tilman Esser, Philipp Wagner, Harald Abele, Karl Oliver Kagan
    Abstract:

    Objective To examine the frontal space (FS) distance in first-trimester fetuses with bilateral, unilateral or median cleft lip and palate and in those with Retrognathia. Methods This was a retrospective study using stored two-dimensional ultrasound images of fetal profiles that were recorded at the time of the nuchal translucency (NT) scan at three prenatal medical centers. Images of 300 normal fetuses and 53 fetuses with facial defects were obtained. To measure the FS distance, a line was drawn between the anterior edge of the mental protuberance of the mandible and anterior edge of the maxilla (MM line) and extended upwards in front of the forehead. The perpendicular distance (FS distance) between the MM line and the skin at the point of largest excursion of the fetal forehead was measured. In cases in which the MM line was located anteriorly to the forehead, the distance was measured in the same fashion but was multiplied by −1. Two operators measured the FS distance twice, independently of each other. FS distances were transformed into Z-scores based on the linear relationship with crown–rump length (CRL) in normal fetuses. The distribution of FS distances in fetuses with bilateral, unilateral or median cleft lip and palate and those with Retrognathia were compared with that in the normal group using Student's t-test. Results A search of the centers' databases identified 53 abnormal cases including 20, nine and eight with a bilateral, unilateral and median cleft lip and palate, respectively, and 16 cases of Retrognathia. In fetuses with bilateral, unilateral and median clefts and those with Retrognathia, median delta NT was 1.00 mm, 0.37 mm, 4.00 mm and 0.26 mm, respectively. Among these affected groups, 12 (60.0%), six (66.7%), two (25.0%) and eight (50.0%) fetuses had an abnormal karyotype. In the normal population, FS distance was dependent on CRL measurement (FS = 6.62 − (0.08 × CRL); r = –0.539; P 

  • frontal space distance in facial clefts and Retrognathia at 11 13 weeks gestation
    Ultrasound in Obstetrics & Gynecology, 2016
    Co-Authors: M Hoopmann, Jiri Sonek, Tilman Esser, C M Bilardo, Philipp Wagner, Harald Abele, Karl Oliver Kagan
    Abstract:

    Objective To examine the frontal space (FS) distance in first-trimester fetuses with bilateral, unilateral or median cleft lip and palate and in those with Retrognathia. Methods This was a retrospective study using stored two-dimensional ultrasound images of fetal profiles that were recorded at the time of the nuchal translucency (NT) scan at three prenatal medical centers. Images of 300 normal fetuses and 53 fetuses with facial defects were obtained. To measure the FS distance, a line was drawn between the anterior edge of the mental protuberance of the mandible and anterior edge of the maxilla (MM line) and extended upwards in front of the forehead. The perpendicular distance (FS distance) between the MM line and the skin at the point of largest excursion of the fetal forehead was measured. In cases in which the MM line was located anteriorly to the forehead, the distance was measured in the same fashion but was multiplied by −1. Two operators measured the FS distance twice, independently of each other. FS distances were transformed into Z-scores based on the linear relationship with crown–rump length (CRL) in normal fetuses. The distribution of FS distances in fetuses with bilateral, unilateral or median cleft lip and palate and those with Retrognathia were compared with that in the normal group using Student's t-test. Results A search of the centers' databases identified 53 abnormal cases including 20, nine and eight with a bilateral, unilateral and median cleft lip and palate, respectively, and 16 cases of Retrognathia. In fetuses with bilateral, unilateral and median clefts and those with Retrognathia, median delta NT was 1.00 mm, 0.37 mm, 4.00 mm and 0.26 mm, respectively. Among these affected groups, 12 (60.0%), six (66.7%), two (25.0%) and eight (50.0%) fetuses had an abnormal karyotype. In the normal population, FS distance was dependent on CRL measurement (FS = 6.62 − (0.08 × CRL); r = –0.539; P < 0.0001). In fetuses with a bilateral and median cleft and in those with Retrognathia, FS distance was significantly different from that in the normal population (all P < 0.0001), however, the difference was not significant in fetuses with unilateral clefts (P = 0.103). The respective Z-scores of FS distance for fetuses with bilateral, unilateral and median clefts and Retrognathia were −9.7 ± 2.0, −3.1 ± 5.1, 8.2 ± 3.4 and −7.3 ± 2.3. Measurements were ≥ 99th and ≤ 1st centiles in all but one (98.1%) case. Conclusion The FS distance appears to be a helpful tool in the detection of facial clefts at 11–13 weeks' gestation. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Gang Shen - One of the best experts on this subject based on the ideXlab platform.

  • Soft tissue linear evaluation of fixed Twin-block appliance treatment and tooth extraction in skeletal Class II malocclusion
    Shanghai kou qiang yi xue = Shanghai journal of stomatology, 2015
    Co-Authors: Yao Gong, Hong-hong Wang, Bin Wei, Gang Shen
    Abstract:

    Purpose This cephalometric study was designed to evaluate the soft tissue profile effects of Twin-block combined with straight wire appliances to treat growing adolescents with skeletal Class II malocclusion and mandibular Retrognathia. Methods The samples comprised 31 growing individuals with skeletal Class II and mandibular Retrognathia. They were divided into 2 groups. The study group (18 patients) was treated with fixed Twin-block combined with fixed appliance, while the control group (13 patients) was only treated with fixed appliance after tooth extraction. Pretreatment and posttreatment lateral cephalograms were taken before and after Twin-block treatment and after all the fixed appliance treatment. Linear cephalometric measurements of soft tissue were analyzed statistically. Intragroup and intergroup changes of the 2 groups were evaluated using SPSS 15.0 software package. Results Significant changes of G'-Pg', Li-1, Si-B and Ls-E line between before and after treatment were found in the study group, while Li-1, Ls-E line and Li-E line changed significantly in control group. The change of Li-E line was different between the 2 groups. Conclusions Twin-block combined with fixed appliance treatment is better than extraction with fixed appliance treatment in promoting lower facial profile in cases of skeletal Class II malocclusion and mandibular Retrognathia with growth potentials.

  • Efficacy evaluation of fixed Twin-block appliance and tooth extraction in skeletal Class II malocclusion
    Shanghai kou qiang yi xue = Shanghai journal of stomatology, 2014
    Co-Authors: Yao Gong, Hong-hong Wang, Bin Wei, Gang Shen
    Abstract:

    PURPOSE To evaluate the skeletal and dentoalveolar effects of Twin-Block combined with straight wire appliances and tooth extraction in the treatment of skeletal Class II malocclusion with mandibular Retrognathia in growing individuals. METHODS The sample comprised 31 growing individuals with skeletal Class II and mandibular Retrognathia, divided into 2 groups. One group (18 patients) was treated with fixed Twin-block combined with fixed appliance; the other group (13 patients) was only treated with fixed appliance after tooth extraction. Lateral cephalograms pretreatment and posttreatment were taken before and after Twin-block treatment and after all fixed appliance treatment. Pancherz's cephalometric measurements were analyzed statistically. Intragroup and intergroup changes of the two groups were evaluated by test using SPSS 15.0 software package. RESULTS According to Pancherz's analysis, mandibular length increased, point Pg, mandibular incisors and first molars moved forward, maxillary incisors moved backward, overjet decreased (P