Current concepts of clinical orthodontic tooth movement are misleading. Traditionally, these have... more Current concepts of clinical orthodontic tooth movement are misleading. Traditionally, these have been described as dependent on force levels and being tipping/bodily in nature. The following is a reevaluation of the relationships between tooth movement and orthodontic mechanotherapy not usually considered when analyzing tooth movement clinically. It is our contention that confusion as to the biological response(s) to mechanical force is derived from in vivo orthodontic trials where conditions are undefined. This correlates with variable biological responses within the periodontium. Constantly changing moment to force ratios inherent to the dynamic load deflection rates of any system used to move a tooth cause changing tendencies for crown/root tipping. This implies that the accepted notion of static translatory tooth movement, although a useful didactic concept, is currently unattainable. In actuality, it has never been documented empirically using any conventional orthodontic appliance.
Aims: To determine if restoration location and/or execution behavior force parameters have an inf... more Aims: To determine if restoration location and/or execution behavior force parameters have an influence on the mechanical properties of bulk-fill composite dental restorations. Methods: Pressure transducers were placed within each quadrant of dental mannequin jaws. Cylindrical molds were placed above the transducers and filled with two bulk-fill composite materials, Filtek and Tetric, by four experienced dentists. Each dentist prepared five specimens per quadrant and material. The total placement time, mean force, number of peak forces (above 25 N), and mean peak(s) force during placement were measured. Then, the stiffness and maximal compressive strength of the specimens were determined while loading the specimens up to failure using a universal loading machine. Results: Placement time was affected by jaw (p < 0.004) and side (p < 0.029), with the shortest time demonstrated for the left side of the mandible. Force exerted during restoration placement was not normally distribu...
International Journal of Environmental Research and Public Health, 2022
The current study aimed to characterize the activity in orthodontic clinics during the COVID-19-i... more The current study aimed to characterize the activity in orthodontic clinics during the COVID-19-induced lockdown and the inter-lockdown periods, as well as to evaluate patients’ perspectives with respect to their fears, their extent of cooperation with treatment, and their emergency needs during the lockdown. The data were gathered from 11 private orthodontic clinics from 1 January 2020 to 8 March 2021, which included three lockdowns and inter-lockdowns. Information specifying the number of admissions, missed appointments, and emergency visits was gathered. Four hundred and twenty-nine orthodontic patients treated in those clinics agreed to complete a questionnaire that evaluated their concerns and expectations, the treatment emergency issues, implementation of the orthodontist’s instructions, and contact with the clinical staff during lockdowns. There was a significant increase in the number of scheduled appointments during the inter-lockdown periods, compared with the pre-pandemic...
The aim of this study was to characterize dental anomalies. The pretreatment records (photographs... more The aim of this study was to characterize dental anomalies. The pretreatment records (photographs and radiographs) of 2897 patients (41.4% males and 58.6% females) were utilized to detect dental anomalies. The dental anomalies studied were related to number, size and shape, position, and eruption. A Chi-square test was carried out to detect associations between dental anomalies, jaw, and sex. A total of 1041 (36%) of the subjects manifested at least one dental anomaly. The prevalence of all dental anomalies was jaw-dependent and greater in the maxilla, except for submerged and transmigrated teeth. The most frequently missing teeth were the maxillary lateral incisor (62.3%) and the mandibular second premolars (60.6%). The most frequent supernumerary teeth were the incisors in the maxilla (97%) and the first premolars in the mandible (43%). Dental anomalies are more frequent in the maxilla and mainly involve the anterior teeth; in the mandible, however, it is the posterior teeth. Thes...
Objectives To investigate the effect of Class II intermaxillary elastics on the functional occlus... more Objectives To investigate the effect of Class II intermaxillary elastics on the functional occlusal plane (FOP) of growing patients. Materials and Methods A total of 50 participants aged 11 to 16 years were selected from a university clinic archive >1-year after treatment and after undergoing 6 months of Class II elastic wear, taking pretreatment (T0) and posttreatment (T1) lateral cephalometric radiographs, and consenting to participate at recall (T2). Participants were divided into 3 groups according to skeletal pattern or into 2 groups according to treatment with extraction (E) or nonextraction (NE). Angular changes of FOP relative to the Sella-Nasion (SN), mandibular plane (MP), and Frankfort horizontal (FH) were compared within and between groups. Results A statistically significant reduction of FOP-SN/FH, but not of FOP-MP, was found from T0–T1–T2 when all patients were grouped together. FOP-SN/MP/FH was significantly the largest in the patients with a hyperdivergent skelet...
Tooth transposition is a relatively rare dental anomaly of interchange in position of two adjacen... more Tooth transposition is a relatively rare dental anomaly of interchange in position of two adjacent teeth. AIM To determine the prevalence and distribution of canine transposition in a sample of orthodontic patients and present treatment alternatives and outcome. STUDY DESIGN The records of 3000 consecutively treated orthodontic patients from a university clinic were surveyed to detect canine transposition in both dental arches. The data was recorded according to gender, age, number and location. RESULTS Canine transpositions were detected in 15 subjects, 3 (20%) males and 12 (80%) females presenting a prevalence of 0.5%. Of them, 6 were between the maxillary canine and first premolar, 7 between the maxillary canine and lateral incisor, 2 transpositions were between the mandibular canine and the lateral incisor. A female to male ratio of 4:1 with left side predominance was found. Treatment options include extracting the transposed teeth, maintaining them in their transposed position,...
Accurate assessment of dental student performance during preclinical operative mannequin courses ... more Accurate assessment of dental student performance during preclinical operative mannequin courses is an essential milestone within the educational process. Training on novel, multicolored 3D-printed teeth resulted in higher performances of the students in comparison to training on standard, monochromatic plastic teeth. However, low reliability of students’ grading using standard, monochromatic plastic teeth was reported. The aim of this study was to verify whether the use of 3D multicolored teeth can (1) provide better inter- and intra-examiner reliability, and (2) assess the effect of instructors’ experience on their reliability. The novel tooth analogs consisted of digitally planned and 3D-printed plastic teeth containing green, yellow, and red stratifications according to increasing depths of preparation. Thirty-seven dental students performed three Class I preparations on the 3D-printed teeth, and these underwent blind evaluation by two examiners of varied experience at two timep...
Quintessence international (Berlin, Germany: 1985)
Impaction of both mandibular canine and lateral incisor is a rare clinical finding which is often... more Impaction of both mandibular canine and lateral incisor is a rare clinical finding which is often treated by way of surgical extraction. This decision is often taken because of the anatomical limitations presented by the mandible, and the horizontal position of the impacted teeth, which have occasionally transmigrated, placing them in close proximity to the roots of neighboring teeth and with a high risk for causing their resorption. In addition, this condition significantly increases the likelihood that the area involved will undergo gingival recession and loss of crestal bone if an unsophisticated ortho-surgical approach is undertaken. The present report describes a novel ortho-surgical technique which maintains the alveolar crestal bone and utilizes a lingual arch attached to the first molars with traction through tunneling with super-elastic springs. This combined approach eliminated the need for extraction of the impacted teeth, and accomplished their full alignment without any...
Objective: The objectives of the study were to examine the distal movement of the maxillary first... more Objective: The objectives of the study were to examine the distal movement of the maxillary first molars (M1) in absence or presence of the maxillary second molar (M2). Method: 56 headgear (HG) patients were divided into two groups according to absence (G-7) or presence (G+7) of M2. G-7 and G+7 included 21 and 35 subjects, mean age 11.95±5.92y and 13.05±1.55y, respectively. Tightness of dental contact point (TDCP) and space were measured between the second premolar and first molar, at 6 levels of HG force (0-15 N) along three time-points of HG treatment (T0= start, T1= 6 months, T2= 12 months. Statistical analysis included ANOVA and Pearson’s correlation. Result: With increase in HG force, at all 3 time points, TDCP decreased and space increased. A relationship between TDCP, time and the presence/absence of maxillary M2 was found (p<0.001). At T0, there was in G+7 a non-significant reduction in TDCP (13%,) and increase in space (15%) and in the G-7 a 25% decrease of TDCP and 31% ...
American Journal of Orthodontics and Dentofacial Orthopedics, 2014
A quantitative assessment of maxillary first molar distalization with and without the maxillary s... more A quantitative assessment of maxillary first molar distalization with and without the maxillary second molar (M2) was carried out. Fifty-six cervical headgear patients undergoing fixed appliance orthodontic treatment were divided into 2 groups: before (G - M2) and after (G + M2) eruption of the maxillary second molars (ages, 11.87 ± 1.20, and 13.05 ± 1.55 years, respectively). The tightness of the dental contact point (TDCP) and the space between the second premolar and the maxillary first molar were measured at 6 levels of headgear force (0-15 N) at 3 intervals 6 months apart (T0, T1, T2). Relationships were found between space and TDCP, time, and presence or absence of the maxillary second molar at T1 and T2 (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). The TDCP decreased and space increased with increase in initial headgear force. An increase in initial force beyond 6 to 9 N did not significantly increase the initial maxillary first molar distalization. The G - M2 TDCP and space measurements were similar to those of G + M2 at T2 with the eruption of the maxillary second molar. From T0 to T1, maxillary first molar distalization was greater in G - M2. In comparison with our previous headgear-alone study, initial distalization with a fully bonded appliance was reduced by 4-fold. Headgear therapy is more effective before the eruption of the maxillary second molar. Once it erupts, the distalization pace of the maxillary first molar is reduced, but it can nevertheless be pursued at a slower pace when the maxillary second molar is present.
Morphological indicators within the cranium for prediction of mandibular growth patterns as repor... more Morphological indicators within the cranium for prediction of mandibular growth patterns as reported by Bjork are: (1) inclination of the condylar head (ICH), (2) curvature of mandibular canal (CMC), (3) shape of the lower border of the mandible and specifically depth of the antegonial notch (AN), (4) inclination of the symphysis (ISY), (5) interincisal angle (IIA), (6) intermolar angle (IMA), and (7) lower anterior face height (LAFH). The purpose of this study was to examine the association of these indicators as they relate to extreme skeletal patterns observed in skeletally mature subjects. The pre-treatment lateral cephalometric radiographs of 395 post-growth subjects were randomly selected from the archives of a university orthodontic department. These were divided in three groups according to their MP-SN angle [normal: 28-36degrees (G1), hypodivergent: ≤26degrees (G2), hyperdivergent: ≥38degrees (G3)]. It was found that only LAFH was correlated to age across all groups. Howeve...
Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie, 2015
The goal of this study was to compare sagittal jaw relationships derived from standardized profil... more The goal of this study was to compare sagittal jaw relationships derived from standardized profile photographs (soft tissue) to those derived from lateral cephalograms (hard tissue) with respect to Angle's classification of malocclusion. A total of 110 randomly selected subjects (mean age: 13.75 ± 1.46 years) undergoing treatment (Postgraduate Program in Orthodontics at Tel Aviv University) were assigned to three groups based on Angle's classification (Class I: n = 30; Class II: n = 50; Class III: n = 30). Standardized profile-view photographs and lateral radiographs (cephalograms) were compared using 11 soft tissue and 8 skeletal measurements, respectively. Tragus, infra-orbital, nasion, A point, B point, and pogonion were found to be the most reliable soft tissue reference points. A similar pattern of diversity was found between the three groups of Angle's classification (Class I/II/III) for the photographic soft,-tissue and the radiographic skeletal measurements (e.g....
Anchorage loss (AL) is a potential side effect of orthodontic mechanotherapy. In the present stud... more Anchorage loss (AL) is a potential side effect of orthodontic mechanotherapy. In the present study, it is defined as the amount of mesial movement of the upper first permanent molar during premolar extraction space closure. In addition, AL is described as a multifactorial response in relation to the extraction site, appliance type, age, crowding, and overjet. For this study, 87 university clinic and private practice subjects, who were defined as maximum anchorage cases and had undergone bilateral maxillary premolar extractions, were divided into four groups according to extraction site (first vs second premolars), mechanics (lingual vs labial edgewise appliances), and age (adolescents vs adults). Overjet and crowding were examined from the overall sample. Data were collected from serial lateral cephalograms and dental casts. The results showed that as the severity of dental crowding increased, AL significantly decreased (r = -0.66, P = .001). Labial edgewise appliances demonstrated ...
All force systems applied to a tooth are composed of either single forces and/or couples. The app... more All force systems applied to a tooth are composed of either single forces and/or couples. The application of a force through the center of resistance of a tooth will result in translation of the tooth. The application of a force to act at points other than through the center of resistance of a tooth will produce different tendencies for rotation. Tooth rotation resulting from the application of a force always creates a simultaneous tendency to move the center of resistance of a tooth in the direction the force is acting. In contrast, the location of a couple on a tooth is irrelevant to the resulting tooth movement. A couple can never move the center of resistance, and with a couple the center of rotation and the center of resistance will always be coincident. The equilibrium forces, associated with a moment of a couple, also are single-point forces and can produce different tooth movements depending on where they are applied. All tooth movement must be either translation and/or rota...
Current concepts of clinical orthodontic tooth movement are misleading. Traditionally, these have... more Current concepts of clinical orthodontic tooth movement are misleading. Traditionally, these have been described as dependent on force levels and being tipping/bodily in nature. The following is a reevaluation of the relationships between tooth movement and orthodontic mechanotherapy not usually considered when analyzing tooth movement clinically. It is our contention that confusion as to the biological response(s) to mechanical force is derived from in vivo orthodontic trials where conditions are undefined. This correlates with variable biological responses within the periodontium. Constantly changing moment to force ratios inherent to the dynamic load deflection rates of any system used to move a tooth cause changing tendencies for crown/root tipping. This implies that the accepted notion of static translatory tooth movement, although a useful didactic concept, is currently unattainable. In actuality, it has never been documented empirically using any conventional orthodontic appliance.
Aims: To determine if restoration location and/or execution behavior force parameters have an inf... more Aims: To determine if restoration location and/or execution behavior force parameters have an influence on the mechanical properties of bulk-fill composite dental restorations. Methods: Pressure transducers were placed within each quadrant of dental mannequin jaws. Cylindrical molds were placed above the transducers and filled with two bulk-fill composite materials, Filtek and Tetric, by four experienced dentists. Each dentist prepared five specimens per quadrant and material. The total placement time, mean force, number of peak forces (above 25 N), and mean peak(s) force during placement were measured. Then, the stiffness and maximal compressive strength of the specimens were determined while loading the specimens up to failure using a universal loading machine. Results: Placement time was affected by jaw (p < 0.004) and side (p < 0.029), with the shortest time demonstrated for the left side of the mandible. Force exerted during restoration placement was not normally distribu...
International Journal of Environmental Research and Public Health, 2022
The current study aimed to characterize the activity in orthodontic clinics during the COVID-19-i... more The current study aimed to characterize the activity in orthodontic clinics during the COVID-19-induced lockdown and the inter-lockdown periods, as well as to evaluate patients’ perspectives with respect to their fears, their extent of cooperation with treatment, and their emergency needs during the lockdown. The data were gathered from 11 private orthodontic clinics from 1 January 2020 to 8 March 2021, which included three lockdowns and inter-lockdowns. Information specifying the number of admissions, missed appointments, and emergency visits was gathered. Four hundred and twenty-nine orthodontic patients treated in those clinics agreed to complete a questionnaire that evaluated their concerns and expectations, the treatment emergency issues, implementation of the orthodontist’s instructions, and contact with the clinical staff during lockdowns. There was a significant increase in the number of scheduled appointments during the inter-lockdown periods, compared with the pre-pandemic...
The aim of this study was to characterize dental anomalies. The pretreatment records (photographs... more The aim of this study was to characterize dental anomalies. The pretreatment records (photographs and radiographs) of 2897 patients (41.4% males and 58.6% females) were utilized to detect dental anomalies. The dental anomalies studied were related to number, size and shape, position, and eruption. A Chi-square test was carried out to detect associations between dental anomalies, jaw, and sex. A total of 1041 (36%) of the subjects manifested at least one dental anomaly. The prevalence of all dental anomalies was jaw-dependent and greater in the maxilla, except for submerged and transmigrated teeth. The most frequently missing teeth were the maxillary lateral incisor (62.3%) and the mandibular second premolars (60.6%). The most frequent supernumerary teeth were the incisors in the maxilla (97%) and the first premolars in the mandible (43%). Dental anomalies are more frequent in the maxilla and mainly involve the anterior teeth; in the mandible, however, it is the posterior teeth. Thes...
Objectives To investigate the effect of Class II intermaxillary elastics on the functional occlus... more Objectives To investigate the effect of Class II intermaxillary elastics on the functional occlusal plane (FOP) of growing patients. Materials and Methods A total of 50 participants aged 11 to 16 years were selected from a university clinic archive >1-year after treatment and after undergoing 6 months of Class II elastic wear, taking pretreatment (T0) and posttreatment (T1) lateral cephalometric radiographs, and consenting to participate at recall (T2). Participants were divided into 3 groups according to skeletal pattern or into 2 groups according to treatment with extraction (E) or nonextraction (NE). Angular changes of FOP relative to the Sella-Nasion (SN), mandibular plane (MP), and Frankfort horizontal (FH) were compared within and between groups. Results A statistically significant reduction of FOP-SN/FH, but not of FOP-MP, was found from T0–T1–T2 when all patients were grouped together. FOP-SN/MP/FH was significantly the largest in the patients with a hyperdivergent skelet...
Tooth transposition is a relatively rare dental anomaly of interchange in position of two adjacen... more Tooth transposition is a relatively rare dental anomaly of interchange in position of two adjacent teeth. AIM To determine the prevalence and distribution of canine transposition in a sample of orthodontic patients and present treatment alternatives and outcome. STUDY DESIGN The records of 3000 consecutively treated orthodontic patients from a university clinic were surveyed to detect canine transposition in both dental arches. The data was recorded according to gender, age, number and location. RESULTS Canine transpositions were detected in 15 subjects, 3 (20%) males and 12 (80%) females presenting a prevalence of 0.5%. Of them, 6 were between the maxillary canine and first premolar, 7 between the maxillary canine and lateral incisor, 2 transpositions were between the mandibular canine and the lateral incisor. A female to male ratio of 4:1 with left side predominance was found. Treatment options include extracting the transposed teeth, maintaining them in their transposed position,...
Accurate assessment of dental student performance during preclinical operative mannequin courses ... more Accurate assessment of dental student performance during preclinical operative mannequin courses is an essential milestone within the educational process. Training on novel, multicolored 3D-printed teeth resulted in higher performances of the students in comparison to training on standard, monochromatic plastic teeth. However, low reliability of students’ grading using standard, monochromatic plastic teeth was reported. The aim of this study was to verify whether the use of 3D multicolored teeth can (1) provide better inter- and intra-examiner reliability, and (2) assess the effect of instructors’ experience on their reliability. The novel tooth analogs consisted of digitally planned and 3D-printed plastic teeth containing green, yellow, and red stratifications according to increasing depths of preparation. Thirty-seven dental students performed three Class I preparations on the 3D-printed teeth, and these underwent blind evaluation by two examiners of varied experience at two timep...
Quintessence international (Berlin, Germany: 1985)
Impaction of both mandibular canine and lateral incisor is a rare clinical finding which is often... more Impaction of both mandibular canine and lateral incisor is a rare clinical finding which is often treated by way of surgical extraction. This decision is often taken because of the anatomical limitations presented by the mandible, and the horizontal position of the impacted teeth, which have occasionally transmigrated, placing them in close proximity to the roots of neighboring teeth and with a high risk for causing their resorption. In addition, this condition significantly increases the likelihood that the area involved will undergo gingival recession and loss of crestal bone if an unsophisticated ortho-surgical approach is undertaken. The present report describes a novel ortho-surgical technique which maintains the alveolar crestal bone and utilizes a lingual arch attached to the first molars with traction through tunneling with super-elastic springs. This combined approach eliminated the need for extraction of the impacted teeth, and accomplished their full alignment without any...
Objective: The objectives of the study were to examine the distal movement of the maxillary first... more Objective: The objectives of the study were to examine the distal movement of the maxillary first molars (M1) in absence or presence of the maxillary second molar (M2). Method: 56 headgear (HG) patients were divided into two groups according to absence (G-7) or presence (G+7) of M2. G-7 and G+7 included 21 and 35 subjects, mean age 11.95±5.92y and 13.05±1.55y, respectively. Tightness of dental contact point (TDCP) and space were measured between the second premolar and first molar, at 6 levels of HG force (0-15 N) along three time-points of HG treatment (T0= start, T1= 6 months, T2= 12 months. Statistical analysis included ANOVA and Pearson’s correlation. Result: With increase in HG force, at all 3 time points, TDCP decreased and space increased. A relationship between TDCP, time and the presence/absence of maxillary M2 was found (p<0.001). At T0, there was in G+7 a non-significant reduction in TDCP (13%,) and increase in space (15%) and in the G-7 a 25% decrease of TDCP and 31% ...
American Journal of Orthodontics and Dentofacial Orthopedics, 2014
A quantitative assessment of maxillary first molar distalization with and without the maxillary s... more A quantitative assessment of maxillary first molar distalization with and without the maxillary second molar (M2) was carried out. Fifty-six cervical headgear patients undergoing fixed appliance orthodontic treatment were divided into 2 groups: before (G - M2) and after (G + M2) eruption of the maxillary second molars (ages, 11.87 ± 1.20, and 13.05 ± 1.55 years, respectively). The tightness of the dental contact point (TDCP) and the space between the second premolar and the maxillary first molar were measured at 6 levels of headgear force (0-15 N) at 3 intervals 6 months apart (T0, T1, T2). Relationships were found between space and TDCP, time, and presence or absence of the maxillary second molar at T1 and T2 (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). The TDCP decreased and space increased with increase in initial headgear force. An increase in initial force beyond 6 to 9 N did not significantly increase the initial maxillary first molar distalization. The G - M2 TDCP and space measurements were similar to those of G + M2 at T2 with the eruption of the maxillary second molar. From T0 to T1, maxillary first molar distalization was greater in G - M2. In comparison with our previous headgear-alone study, initial distalization with a fully bonded appliance was reduced by 4-fold. Headgear therapy is more effective before the eruption of the maxillary second molar. Once it erupts, the distalization pace of the maxillary first molar is reduced, but it can nevertheless be pursued at a slower pace when the maxillary second molar is present.
Morphological indicators within the cranium for prediction of mandibular growth patterns as repor... more Morphological indicators within the cranium for prediction of mandibular growth patterns as reported by Bjork are: (1) inclination of the condylar head (ICH), (2) curvature of mandibular canal (CMC), (3) shape of the lower border of the mandible and specifically depth of the antegonial notch (AN), (4) inclination of the symphysis (ISY), (5) interincisal angle (IIA), (6) intermolar angle (IMA), and (7) lower anterior face height (LAFH). The purpose of this study was to examine the association of these indicators as they relate to extreme skeletal patterns observed in skeletally mature subjects. The pre-treatment lateral cephalometric radiographs of 395 post-growth subjects were randomly selected from the archives of a university orthodontic department. These were divided in three groups according to their MP-SN angle [normal: 28-36degrees (G1), hypodivergent: ≤26degrees (G2), hyperdivergent: ≥38degrees (G3)]. It was found that only LAFH was correlated to age across all groups. Howeve...
Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie, 2015
The goal of this study was to compare sagittal jaw relationships derived from standardized profil... more The goal of this study was to compare sagittal jaw relationships derived from standardized profile photographs (soft tissue) to those derived from lateral cephalograms (hard tissue) with respect to Angle's classification of malocclusion. A total of 110 randomly selected subjects (mean age: 13.75 ± 1.46 years) undergoing treatment (Postgraduate Program in Orthodontics at Tel Aviv University) were assigned to three groups based on Angle's classification (Class I: n = 30; Class II: n = 50; Class III: n = 30). Standardized profile-view photographs and lateral radiographs (cephalograms) were compared using 11 soft tissue and 8 skeletal measurements, respectively. Tragus, infra-orbital, nasion, A point, B point, and pogonion were found to be the most reliable soft tissue reference points. A similar pattern of diversity was found between the three groups of Angle's classification (Class I/II/III) for the photographic soft,-tissue and the radiographic skeletal measurements (e.g....
Anchorage loss (AL) is a potential side effect of orthodontic mechanotherapy. In the present stud... more Anchorage loss (AL) is a potential side effect of orthodontic mechanotherapy. In the present study, it is defined as the amount of mesial movement of the upper first permanent molar during premolar extraction space closure. In addition, AL is described as a multifactorial response in relation to the extraction site, appliance type, age, crowding, and overjet. For this study, 87 university clinic and private practice subjects, who were defined as maximum anchorage cases and had undergone bilateral maxillary premolar extractions, were divided into four groups according to extraction site (first vs second premolars), mechanics (lingual vs labial edgewise appliances), and age (adolescents vs adults). Overjet and crowding were examined from the overall sample. Data were collected from serial lateral cephalograms and dental casts. The results showed that as the severity of dental crowding increased, AL significantly decreased (r = -0.66, P = .001). Labial edgewise appliances demonstrated ...
All force systems applied to a tooth are composed of either single forces and/or couples. The app... more All force systems applied to a tooth are composed of either single forces and/or couples. The application of a force through the center of resistance of a tooth will result in translation of the tooth. The application of a force to act at points other than through the center of resistance of a tooth will produce different tendencies for rotation. Tooth rotation resulting from the application of a force always creates a simultaneous tendency to move the center of resistance of a tooth in the direction the force is acting. In contrast, the location of a couple on a tooth is irrelevant to the resulting tooth movement. A couple can never move the center of resistance, and with a couple the center of rotation and the center of resistance will always be coincident. The equilibrium forces, associated with a moment of a couple, also are single-point forces and can produce different tooth movements depending on where they are applied. All tooth movement must be either translation and/or rota...
Uploads
Papers by Moshe Davidovitch