The Chinese journal of dental research : the official journal of the Scientific Section of the Chinese Stomatological Association (CSA), 2016
To compare the influence of outer bow length difference and unilateral outer bow expansion on the... more To compare the influence of outer bow length difference and unilateral outer bow expansion on the 'asymmetric effect' of the headgear. Twelve 3D finite element models of a headgear with two tubes were designed, which were similar except for the outer bow length or the degree of unilateral expansion in Solid-Works 2011. A 3N force was applied to the outer bow ends in ANSYS Workbench 12.1 and the distalising, lateral forces to molars, moments and the energy of the system were evaluated. As the degree of unilateral expansion increased, the net differences in all findings were increased up to a point, and then changed. There was an increasing pattern in the length difference group. Buccal movement was observed in the intact/shorter side molar. Unilateral shortened outer bow asymmetric headgears are more efficient and more predictable in clinical application than the unilateral outer bow expansion.
The aim of this study was to establish cephalometric soft tissue norms in a Lebanese population o... more The aim of this study was to establish cephalometric soft tissue norms in a Lebanese population of young adults and profile differences between males and females. Ninety subjects divided into 43 women and 47 men, aged from 18 to 30 years, were selected based on specific criteria. The lateral cephalograms were taken in the natural head position. Holdaway, Steiner, Merrifield, Ricketts, Epker and Fish analyses were applied as conventional analyses. Scheideman, Spradley, Cooke, Arnett, Bergman, Farkas and Viazis analyses were applied as analyses based on the true vertical. The specific soft tissue measurements of this sample are reported in six grids. The differences between males and females related especially to the lower facial height and lip thickness, which had higher values in males, who also presented a more retruded lower lip and more protruded nasal tip. Women had higher values for mentolabial and frontonasal angles.
The aims of this study were to investigate the association between normative and perceived orthod... more The aims of this study were to investigate the association between normative and perceived orthodontic treatment need in a Lebanese population and the effect of sociodemographic status on orthodontic treatment need. A prospective cross-sectional clinical study was designed using a sample of 150 subjects (81 males and 69 females) aged 11-18years seeking dental treatment at Beirut Arab University. Normative orthodontic treatment need was scored using the two components of the Index of Orthodontic Treatment Need (IOTN), the Dental Health Component (DHC) and the Aesthetic Component (AC). Perceived need for orthodontic treatment was evaluated by scoring the AC of the IOTN. A total of 31.3% of the sample were in great need of orthodontic treatment according to the DHC of the IOTN. On the other hand, only 9% of the sample perceived their need to be definite. A significant positive but weak correlation was found between the normative and perceived need for orthodontic treatment. There was also a significant association between age and normative treatment need.
Data Revues 17617227 Unassign S1761722712000770, Oct 11, 2012
ABSTRACT L’objectif de cette étude est d’évaluer les effets du microsablage sur la résistance au ... more ABSTRACT L’objectif de cette étude est d’évaluer les effets du microsablage sur la résistance au cisaillement (RAC) initiale et sur le mode de fracture du joint émail/attache d’attaches orthodontiques collées à l’aide d’un primaire automordançant (PAM) au niveau de l’émail vestibulaire et lingual. Les attaches ont été collées en utilisant un PAM et une résine composite sur les surfaces vestibulaires et linguales de 30 prémolaires intactes et sur 30 prémolaires prétraitées par microsablage avec des particules d’oxyde d’aluminium de 50 microns de diamètre. Le test-t de Student pour les séries appariées a été utilisé pour comparer les différences de RAC et le test du Chi2 multiple pour évaluer le mode de fracture. Il a été démontré que le microsablage augmente de façon significative la RAC du PAM au niveau des surfaces vestibulaires. En revanche, l’augmentation au niveau des surfaces linguales n’est pas statistiquement significative. La comparaison des scores de l’indice d’adhésif résiduel montre que la proportion d’adhésif restante au niveau de l’émail traité par microsablage est plus importante que celle restante au niveau de l’émail intact. Par ailleurs, il n’y a pas de différence statistique entre la RAC du PAM au niveau des surfaces vestibulaires et linguales non traitées. Nous pouvons donc conclure, que le microsablage améliore la liaison entre l’émail, vestibulaire ou lingual, et la résine et que le PAM permet d’obtenir la même RAC au niveau des surfaces vestibulaires et linguales intactes.
The aim of this study was to evaluate the importance of using the entire face to assess facial pr... more The aim of this study was to evaluate the importance of using the entire face to assess facial profile attractiveness. The secondary objective was to assess the facial profile preferences of orthodontists, dentists and laypeople. Two original cephalometric radiographs of two subjects (one man and one woman meeting the normality criteria) and 16 modified samples of these radiographs were used. The 18 radiographs were then converted into silhouettes and printed twice: the entire profile (A) and the lower third alone (B). The silhouettes were randomly distributed into two binders A and B. A survey was conducted using three panels of evaluators: orthodontists, dentists and laypeople. The esthetic appreciation was quantified according to the Visual Analogue Scale (VAS). Pearson's correlation coefficient was calculated to compare the scores of the entire profile with the scores of the lower third alone. The results showed that the orthodontists panel presented a much better correlation between A and B compared to dentists and especially to laypeople. A comparison of profile scores with the correlation coefficients shows that the profiles with the highest scores present the lowest correlations. The three panels of evaluators preferred the orthogonal profiles or profiles with upper lip protrusion over profiles with lower lip protrusion. For profiles with values close to the norm, the lower face alone does not reveal the attractiveness of the entire facial profile. Hence, the importance of using the entire facial profile to assess the beauty of the face.
Dans les applications à long terme de produits fluorés, les ions fluor provoquent la corrosion de... more Dans les applications à long terme de produits fluorés, les ions fluor provoquent la corrosion des attaches orthodontiques en titane. Le gel fluoré, utilisé pour la prévention des caries pendant le traitement orthodontique, a une teneur très élevée en ions fluor et, par conséquent, est susceptible de provoquer la corrosion de ces attaches en titane. L’objectif principal de cette étude a été de déterminer l’effet produit par l’élimination, par rinçage, du gel fluoré résiduel sur la corrosion des attaches en titane. L’objectif secondaire était de chercher à évaluer la quantité de corrosion de ces attaches en présence du gel fluoré.Cent attaches en titane ont été réparties en cinq groupes de 20 chacun. Le groupe 1 était le groupe témoin ; les autres groupes ont été immergés dans du gel fluoré : le groupe 2, immersion pendant quatre minutes et maintien pendant 30 minutes revêtu du gel fluoré résiduel ; le groupe 3, immersion pendant quatre minutes suivie d’un rinçage immédiat à l’eau claire ; le groupe 4, immersion pendant 12 minutes et maintien avec le gel résiduel pendant 90 minutes et le groupe 5, immersion pendant 12 minutes suivie d’un rinçage immédiat à l’eau claire. Tous les groupes ont été rincés, puis séchés pendant 20 heures à l’aide d’un gel de Silice dans un dessiccateur à 37 °C avant d’être testés.Les résultats gravimétriques et l’analyse MEB n’ont montré aucune différence significative entre les groupes 2, 3 et 5 comparés au groupe témoin. Seul le groupe 4 a montré une perte de poids significative et des puits de corrosion sur quatre des 20 attaches. Au niveau de la résistance au glissement, aucune différence significative n’a été relevée dans aucun des groupes.Des applications de courte durée d’un gel fluoré n’ont aucun effet sur la résistance au glissement des attaches en titane. Aucune trace de corrosion n’a été relevée sur ces attaches après une application d’un gel fluoré concentré et certaines attaches ont montré des signes de corrosion après trois applications. Le rinçage du gel fluoré résiduel élimine complètement les risques de corrosion des attaches en titane.
The aim of this study was to analyse the stress and strain distribution in the alveolar bone betw... more The aim of this study was to analyse the stress and strain distribution in the alveolar bone between two central incisors in the process of diastema closure with a constant force. A 3-dimensional computer modeling based on finite element techniques was used for this purpose. A model of an anterior segment of the mandible containing cortical bone, spongy bone, gingivae, PDL and two central incisors with a bracket in the labial surface of each tooth were designed. The von Mises stress and strain was evaluated in alveolar bone along a path of nodes defined in a cresto-apical direction in the midline between two teeth. It was observed that stress and strain of alveolar bone increased in midline with a constant force to close the diastema regardless of the type of movement in gradual steps of diastema closure, however the stress was higher in the tipping movement than the bodily so it can be suggested that a protocol of force system modification should be introduced to compensate for the stress and strain changes caused by the reduced distance to avoid the unwanted stress alteration during the diastema closure.
The Chinese journal of dental research : the official journal of the Scientific Section of the Chinese Stomatological Association (CSA), 2016
To compare the influence of outer bow length difference and unilateral outer bow expansion on the... more To compare the influence of outer bow length difference and unilateral outer bow expansion on the 'asymmetric effect' of the headgear. Twelve 3D finite element models of a headgear with two tubes were designed, which were similar except for the outer bow length or the degree of unilateral expansion in Solid-Works 2011. A 3N force was applied to the outer bow ends in ANSYS Workbench 12.1 and the distalising, lateral forces to molars, moments and the energy of the system were evaluated. As the degree of unilateral expansion increased, the net differences in all findings were increased up to a point, and then changed. There was an increasing pattern in the length difference group. Buccal movement was observed in the intact/shorter side molar. Unilateral shortened outer bow asymmetric headgears are more efficient and more predictable in clinical application than the unilateral outer bow expansion.
The aim of this study was to establish cephalometric soft tissue norms in a Lebanese population o... more The aim of this study was to establish cephalometric soft tissue norms in a Lebanese population of young adults and profile differences between males and females. Ninety subjects divided into 43 women and 47 men, aged from 18 to 30 years, were selected based on specific criteria. The lateral cephalograms were taken in the natural head position. Holdaway, Steiner, Merrifield, Ricketts, Epker and Fish analyses were applied as conventional analyses. Scheideman, Spradley, Cooke, Arnett, Bergman, Farkas and Viazis analyses were applied as analyses based on the true vertical. The specific soft tissue measurements of this sample are reported in six grids. The differences between males and females related especially to the lower facial height and lip thickness, which had higher values in males, who also presented a more retruded lower lip and more protruded nasal tip. Women had higher values for mentolabial and frontonasal angles.
The aims of this study were to investigate the association between normative and perceived orthod... more The aims of this study were to investigate the association between normative and perceived orthodontic treatment need in a Lebanese population and the effect of sociodemographic status on orthodontic treatment need. A prospective cross-sectional clinical study was designed using a sample of 150 subjects (81 males and 69 females) aged 11-18years seeking dental treatment at Beirut Arab University. Normative orthodontic treatment need was scored using the two components of the Index of Orthodontic Treatment Need (IOTN), the Dental Health Component (DHC) and the Aesthetic Component (AC). Perceived need for orthodontic treatment was evaluated by scoring the AC of the IOTN. A total of 31.3% of the sample were in great need of orthodontic treatment according to the DHC of the IOTN. On the other hand, only 9% of the sample perceived their need to be definite. A significant positive but weak correlation was found between the normative and perceived need for orthodontic treatment. There was also a significant association between age and normative treatment need.
Data Revues 17617227 Unassign S1761722712000770, Oct 11, 2012
ABSTRACT L’objectif de cette étude est d’évaluer les effets du microsablage sur la résistance au ... more ABSTRACT L’objectif de cette étude est d’évaluer les effets du microsablage sur la résistance au cisaillement (RAC) initiale et sur le mode de fracture du joint émail/attache d’attaches orthodontiques collées à l’aide d’un primaire automordançant (PAM) au niveau de l’émail vestibulaire et lingual. Les attaches ont été collées en utilisant un PAM et une résine composite sur les surfaces vestibulaires et linguales de 30 prémolaires intactes et sur 30 prémolaires prétraitées par microsablage avec des particules d’oxyde d’aluminium de 50 microns de diamètre. Le test-t de Student pour les séries appariées a été utilisé pour comparer les différences de RAC et le test du Chi2 multiple pour évaluer le mode de fracture. Il a été démontré que le microsablage augmente de façon significative la RAC du PAM au niveau des surfaces vestibulaires. En revanche, l’augmentation au niveau des surfaces linguales n’est pas statistiquement significative. La comparaison des scores de l’indice d’adhésif résiduel montre que la proportion d’adhésif restante au niveau de l’émail traité par microsablage est plus importante que celle restante au niveau de l’émail intact. Par ailleurs, il n’y a pas de différence statistique entre la RAC du PAM au niveau des surfaces vestibulaires et linguales non traitées. Nous pouvons donc conclure, que le microsablage améliore la liaison entre l’émail, vestibulaire ou lingual, et la résine et que le PAM permet d’obtenir la même RAC au niveau des surfaces vestibulaires et linguales intactes.
The aim of this study was to evaluate the importance of using the entire face to assess facial pr... more The aim of this study was to evaluate the importance of using the entire face to assess facial profile attractiveness. The secondary objective was to assess the facial profile preferences of orthodontists, dentists and laypeople. Two original cephalometric radiographs of two subjects (one man and one woman meeting the normality criteria) and 16 modified samples of these radiographs were used. The 18 radiographs were then converted into silhouettes and printed twice: the entire profile (A) and the lower third alone (B). The silhouettes were randomly distributed into two binders A and B. A survey was conducted using three panels of evaluators: orthodontists, dentists and laypeople. The esthetic appreciation was quantified according to the Visual Analogue Scale (VAS). Pearson's correlation coefficient was calculated to compare the scores of the entire profile with the scores of the lower third alone. The results showed that the orthodontists panel presented a much better correlation between A and B compared to dentists and especially to laypeople. A comparison of profile scores with the correlation coefficients shows that the profiles with the highest scores present the lowest correlations. The three panels of evaluators preferred the orthogonal profiles or profiles with upper lip protrusion over profiles with lower lip protrusion. For profiles with values close to the norm, the lower face alone does not reveal the attractiveness of the entire facial profile. Hence, the importance of using the entire facial profile to assess the beauty of the face.
Dans les applications à long terme de produits fluorés, les ions fluor provoquent la corrosion de... more Dans les applications à long terme de produits fluorés, les ions fluor provoquent la corrosion des attaches orthodontiques en titane. Le gel fluoré, utilisé pour la prévention des caries pendant le traitement orthodontique, a une teneur très élevée en ions fluor et, par conséquent, est susceptible de provoquer la corrosion de ces attaches en titane. L’objectif principal de cette étude a été de déterminer l’effet produit par l’élimination, par rinçage, du gel fluoré résiduel sur la corrosion des attaches en titane. L’objectif secondaire était de chercher à évaluer la quantité de corrosion de ces attaches en présence du gel fluoré.Cent attaches en titane ont été réparties en cinq groupes de 20 chacun. Le groupe 1 était le groupe témoin ; les autres groupes ont été immergés dans du gel fluoré : le groupe 2, immersion pendant quatre minutes et maintien pendant 30 minutes revêtu du gel fluoré résiduel ; le groupe 3, immersion pendant quatre minutes suivie d’un rinçage immédiat à l’eau claire ; le groupe 4, immersion pendant 12 minutes et maintien avec le gel résiduel pendant 90 minutes et le groupe 5, immersion pendant 12 minutes suivie d’un rinçage immédiat à l’eau claire. Tous les groupes ont été rincés, puis séchés pendant 20 heures à l’aide d’un gel de Silice dans un dessiccateur à 37 °C avant d’être testés.Les résultats gravimétriques et l’analyse MEB n’ont montré aucune différence significative entre les groupes 2, 3 et 5 comparés au groupe témoin. Seul le groupe 4 a montré une perte de poids significative et des puits de corrosion sur quatre des 20 attaches. Au niveau de la résistance au glissement, aucune différence significative n’a été relevée dans aucun des groupes.Des applications de courte durée d’un gel fluoré n’ont aucun effet sur la résistance au glissement des attaches en titane. Aucune trace de corrosion n’a été relevée sur ces attaches après une application d’un gel fluoré concentré et certaines attaches ont montré des signes de corrosion après trois applications. Le rinçage du gel fluoré résiduel élimine complètement les risques de corrosion des attaches en titane.
The aim of this study was to analyse the stress and strain distribution in the alveolar bone betw... more The aim of this study was to analyse the stress and strain distribution in the alveolar bone between two central incisors in the process of diastema closure with a constant force. A 3-dimensional computer modeling based on finite element techniques was used for this purpose. A model of an anterior segment of the mandible containing cortical bone, spongy bone, gingivae, PDL and two central incisors with a bracket in the labial surface of each tooth were designed. The von Mises stress and strain was evaluated in alveolar bone along a path of nodes defined in a cresto-apical direction in the midline between two teeth. It was observed that stress and strain of alveolar bone increased in midline with a constant force to close the diastema regardless of the type of movement in gradual steps of diastema closure, however the stress was higher in the tipping movement than the bodily so it can be suggested that a protocol of force system modification should be introduced to compensate for the stress and strain changes caused by the reduced distance to avoid the unwanted stress alteration during the diastema closure.
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Papers by Joseph Bouserhal