- Email: [email protected]
Facial growth in the post-menarcheal female
192
Reviews and abstracts
Thesis abstracts Nasal deformity in Afro-American and Caucasian infants with complete unilateral cleft lip and palate Pamela Johnson Department of Orthodontics, University of Illinois, 1991.
The purposes of this retrospective study were to evaluate: (1) the differences due to race, and (2) the effects of surgery, on the cleft nose of Afro-American and white infants with unilateral cleft lip and palate. The sample consisted of 36 infants, 18 in each group. Linear and angular measurements of facial masks were obtained with the Echo 4020/PS Laser System Scanner (Cyberware Laboratories). Maxillary measurements were made directly on dental casts with handheld calipers. Multivariate discriminant function analysis provided significant discrimination between the two groups before and after primary lip closure. The length of the columella and the width of the floor of the nostril were the primary contributors to the preoperative and postoperative differences.
Facial growth in the post-menarcheal female Tim B. Belnap Department of Orthodontics, University of Illinois, 1991.
Growth of the facial skeleton was studied in 25 females for a period of 6 years after menarche. A series of four lateral cephalograms, with approximately 2-year intervals are evaluated for each subject. The initial film in each series corresponded with the subject's menarche date. Analysis of variance showed that significant growth was detected only in sella-gnathion, articularegonion, and articulare-pogonion. Sella-gnathion showed the greatest amount of growth (mean = 3.5 mm) in the first 2 years after menarche. The measurements from articulare to gonion and pogonion showed significance 4 and 6 years after menarche. The results of this investigation show that in postmenarcheal female face, significant growth occurs shortly after menarche and only in the mandible.
Effects of functional appliances on the temporomandibular joint and masticatory muscles in Macaca fascicularis Camilo Yamin Lacouture Factdty of Det2tistr)', Departmenl of Orthodontics, UniverMty of Toronto, 1991.
Previous studies have placed great emphasis on the use of continuous bite registration appliances (Herbst) to achieve clinically significant results in the correction
Am. J. Orthod.Dentofac. Orthop. August 1992
of dysplasias (Pancherz, 1975 and 1982; Metaxas, 1983; Weislander, 1984; Woodside et al., 1987; Voudouris, 1988). This correction, due to increased condylar growth and change in the temporomandibularjoint area, was associated with a decrease in postural electromyographic activity of the muscles of mastication. The purpose of this study was to investigate the effect of an intermittent bite registration appliance (Fr:~nkel) on the temporomandibular joint architecture and electromyographic activity of the masticatory muscles and compare them with the effect of a continuous bite registration appliance (Herbst). The sample consisted of six female juvenile and one male adult cynomologus (Macaca fascicularis) monkeys. A modified Fr~nkel appliance was placed in two of the juvenile animals and in the adult animal. A Herbst appliance was placed in two of the juvenile animals and the other two animals served as controls. Cephalometric and electromyographic methods were used to assess the changes produced by either appliance. After a 12-week experimental period the following changes were observed. Both the modified Frankel and Herbst appliance appeared to be associated with an increased condylar growth response, which, however, was greater in the animals wearing the Herbst appliances. The animals wearing the Herbst appliance also showed greater mandibular length increases, and greater dentoalveolar changes than those wearing the modified Fr~inkel appliance. However, when the total skeletal correction was assessed similar results were observed. The postural electromyographic activity of the four muscles analyzed decreased (p < 0.05) after the insertion of either type of appliance. The functional electromyographic activity reported only in the animals wearing the modified Fr~nkel also decreased (p < 0.05) after the activation of the appliance. Thus the cephalometric clianges in the mandibular condyle with either type of appliance could not be the result of increased muscle activity.
A safe interface for ceramic brackets S. Lacoursiere, R. Maijer, D. C. Smith, N. D. Ruse, and D. G. Woodside Faculty of Dentistry, Department of Orthodontics, University of Toronto, Ontario, Canada, 1991.
Orthodontists have recently been introduced to a new product--the ceramic bracket. The initial reaction from the patient population and practicing orthodontists was promising. However, it was not long before clinical scientific reports documented very high bond strengths, enamel damage, and a high percentage of bracket failure associated with these brackets. The purpose of this in vitro investigation was to compare tensile and shear
Reviews and abstracts
Thesis abstracts Nasal deformity in Afro-American and Caucasian infants with complete unilateral cleft lip and palate Pamela Johnson Department of Orthodontics, University of Illinois, 1991.
The purposes of this retrospective study were to evaluate: (1) the differences due to race, and (2) the effects of surgery, on the cleft nose of Afro-American and white infants with unilateral cleft lip and palate. The sample consisted of 36 infants, 18 in each group. Linear and angular measurements of facial masks were obtained with the Echo 4020/PS Laser System Scanner (Cyberware Laboratories). Maxillary measurements were made directly on dental casts with handheld calipers. Multivariate discriminant function analysis provided significant discrimination between the two groups before and after primary lip closure. The length of the columella and the width of the floor of the nostril were the primary contributors to the preoperative and postoperative differences.
Facial growth in the post-menarcheal female Tim B. Belnap Department of Orthodontics, University of Illinois, 1991.
Growth of the facial skeleton was studied in 25 females for a period of 6 years after menarche. A series of four lateral cephalograms, with approximately 2-year intervals are evaluated for each subject. The initial film in each series corresponded with the subject's menarche date. Analysis of variance showed that significant growth was detected only in sella-gnathion, articularegonion, and articulare-pogonion. Sella-gnathion showed the greatest amount of growth (mean = 3.5 mm) in the first 2 years after menarche. The measurements from articulare to gonion and pogonion showed significance 4 and 6 years after menarche. The results of this investigation show that in postmenarcheal female face, significant growth occurs shortly after menarche and only in the mandible.
Effects of functional appliances on the temporomandibular joint and masticatory muscles in Macaca fascicularis Camilo Yamin Lacouture Factdty of Det2tistr)', Departmenl of Orthodontics, UniverMty of Toronto, 1991.
Previous studies have placed great emphasis on the use of continuous bite registration appliances (Herbst) to achieve clinically significant results in the correction
Am. J. Orthod.Dentofac. Orthop. August 1992
of dysplasias (Pancherz, 1975 and 1982; Metaxas, 1983; Weislander, 1984; Woodside et al., 1987; Voudouris, 1988). This correction, due to increased condylar growth and change in the temporomandibularjoint area, was associated with a decrease in postural electromyographic activity of the muscles of mastication. The purpose of this study was to investigate the effect of an intermittent bite registration appliance (Fr:~nkel) on the temporomandibular joint architecture and electromyographic activity of the masticatory muscles and compare them with the effect of a continuous bite registration appliance (Herbst). The sample consisted of six female juvenile and one male adult cynomologus (Macaca fascicularis) monkeys. A modified Fr~nkel appliance was placed in two of the juvenile animals and in the adult animal. A Herbst appliance was placed in two of the juvenile animals and the other two animals served as controls. Cephalometric and electromyographic methods were used to assess the changes produced by either appliance. After a 12-week experimental period the following changes were observed. Both the modified Frankel and Herbst appliance appeared to be associated with an increased condylar growth response, which, however, was greater in the animals wearing the Herbst appliances. The animals wearing the Herbst appliance also showed greater mandibular length increases, and greater dentoalveolar changes than those wearing the modified Fr~inkel appliance. However, when the total skeletal correction was assessed similar results were observed. The postural electromyographic activity of the four muscles analyzed decreased (p < 0.05) after the insertion of either type of appliance. The functional electromyographic activity reported only in the animals wearing the modified Fr~nkel also decreased (p < 0.05) after the activation of the appliance. Thus the cephalometric clianges in the mandibular condyle with either type of appliance could not be the result of increased muscle activity.
A safe interface for ceramic brackets S. Lacoursiere, R. Maijer, D. C. Smith, N. D. Ruse, and D. G. Woodside Faculty of Dentistry, Department of Orthodontics, University of Toronto, Ontario, Canada, 1991.
Orthodontists have recently been introduced to a new product--the ceramic bracket. The initial reaction from the patient population and practicing orthodontists was promising. However, it was not long before clinical scientific reports documented very high bond strengths, enamel damage, and a high percentage of bracket failure associated with these brackets. The purpose of this in vitro investigation was to compare tensile and shear