Forsus Nitinol Flat Spring and Jasper Jumper corrections of Class II division 1 malocclusions.

OBJECTIVE: To compare the effects of Forsus Nitinol Flat Spring (FNFS) and Jasper Jumper (JJ) in the correction of Class II division I malocclusions. MATERIALS AND METHODS: Our research was conducted on 48 adolescents, who had a normal or horizontal growth pattern and retrognathic mandible. The patients were divided into three equal groups randomly. First group was treated with FNFS, and the second group was treated with JJ appliances, whereas the third group was the control group. Lateral cephalograms and study models were obtained after the leveling phase and at time of the removal of the appliances. RESULTS: Cephalometric analysis revealed that both the appliances stimulated mandibular growth, increased the anterior face height because of the lower face, and elongated the posterior face height because of the growth of temporomandibular joint. Maxillary central incisors were extruded, retruded, and distally tipped. Contrarily, intrusion, protrusion, and labial tipping were observed in the mandibular central incisors. Distal movement and intrusion of the maxillary first molars and mesial movement and extrusion of the mandibular first molars were the other dental alterations. Overjet and overbite were decreased, and a Class I molar relationship and improvement in the profile were attained in both treatment groups. Cast model analysis showed expansion in the maxillary and mandibular dental arches. CONCLUSIONS: Both the appliances were effective in the treatment of Class II malocclusion and revealed nearly same alterations in the skeletal, dental, and soft tissue parameters.

Effects of a segmented removable appliance in molar distalization.

The aim of the present investigation was to evaluate the skeletal and dentoalveolar treatment effects of a segmented removable appliance [removable molar distalizer (RMD)] for molar distalization. The study was conducted on 28 patients (12 females and 16 males), with a mean age of 11.8 years. All presented with a skeletal Class I malocclusion and a bilateral dental Class II molar relationship. The pre- and post-distalization records included lateral head films, study models and standard photographs. The findings were evaluated with a paired samples t-test. The average maxillary first molar distalization with the RMD was 3.98 mm, with 4.61 degrees of distal tipping. The maxillary second premolars drifted distally 2.13 mm on average with 1.54 degrees of distal tipping, while the maxillary first premolars showed 1.23 mm of mesial movement and 1.98 degrees of mesial tipping. The incisors protruded 1.09 mm with 1.27 degrees of labial tipping. The RMD was effective in distal molar movement and all patients attained a bilateral Class I molar relationship in an average period of 4.5 months. Hygiene problems and mucosal irritations, frequently found with fixed intraoral distalization techniques, were not observed during the distalization period.

Effects of nitric oxide in orthodontic tooth movement in rats.

The purpose of this study was to evaluate the role of nitric oxide (NO) in orthodontic tooth movement in rats. Nomega-nitro-L-arginine methyl ester (L-NAME) was used as NO synthase (NOS) inhibitor, and nitro-L-arginine (NLA) was used as NOS precursor. Fifty-four Sprague-Dawley rats were divided into 3 equal groups, and each group was divided into 3 subgroups. In the first 8 subgroups, 20 g of force was applied to the maxillary incisors with a spring. NLA was administered in the first 3 subgroups at 10(-4), 10(-5) and 10(-6) mol/L (20 microL/12 hours), respectively. L-NAME was administered in the next 3 subgroups with the same order, amount, and prescription. The last 3 subgroups were evaluated as control groups; in the seventh subgroup, 0.9% NaCl (saline solution) was injected (20 microL/12 hours). Only the force was administered in the eighth subgroup, and no chemical solution or orthodontic force was used in the last subgroup. The rats were killed on the fifth day of the experiment. Their premaxillae were dissected, and tissue sections were obtained from the coronal, middle, and apical thirds of the incisor roots. Multinuclear osteoclasts, Howship's lacunae, capillary vascularization, and orthodontic tooth movement were significantly increased in the NLA groups compared with the L-NAME and control groups.

Rapid canine distalization using distraction of the periodontal ligament: a preliminary clinical validation of the original technique.

The process of rapid canine distalization through the distraction of the periodontal ligament is similar to the process in the midpalatal suture during rapid palatal expansion. Rapid canine distalization can be achieved in three weeks with this technique. The aim of this research was to evaluate the effects of rapid canine distalization on dentoalveolar tissues during the rapid distalization of canine teeth with semirigid, individual tooth-borne distractors. The study was carried out on 43 canine teeth in 18 (seven male and 11 female) patients who required first premolar extractions. The mean age of the patients was 16.7 years. The second premolars and first molars were used as anchor units. Orthodontic models, cephalometric and panoramic radiographs, and standard photographs of all the patients were taken before treatment and after the consolidation period. Periapical radiographies of the canines and anchor units were obtained once a week during the distalization period. The distractors were activated 0.25 mm three times a day, and the canines were distalized efficiently an average of three weeks. The within-group differences were evaluated with the Wilcoxon test. The maxillary canines were distalized an average of 5.76 mm with 11.47 degrees distal tipping. The maxillary first molars moved mesially 0.56 mm and extruded 0.64 mm. The maxillary incisors showed 1.44 degrees of palatal tipping. The mean distal movement of the mandibular canines was 3.5 mm with 7.16 degrees distal tipping. Anchorage loss was not observed in the mandibular first molars.

Comparison of some effects of acetylsalicylic acid and rofecoxib during orthodontic tooth movement.

The purpose of this study was to examine the effects of 2 different anti-inflammatory drugs on gingival crevicular fluid (GCF) volume and on prostaglandin E(2) (PGE(2)) levels of the GCF during orthodontic tooth movement. A total of 36 extraction patients, aged 17.6 +/- 2.5 years (mean +/- standard deviation), were divided into 3 groups. Acetylsalicylic acid (aspirin) and rofecoxib (Vioxx, Merck, Whitehouse Station, NJ) were used for pain control in the first and second groups; the third group was used as a control. Gingival crevicular fluid was sampled at the beginning of tooth movement and at 24, 48, and 168 hours. An automated enzyme immunoassay was used to measure PGE(2) in GCF. The intragroup differences were evaluated with the Wilcoxon test, and the differences between the groups were determined with the Mann-Whitney U test. Gingival crevicular fluid volumes of the groups did not change significantly during the experimental period. Depending on the variations of fibroblast activation, PGE(2) levels of all the groups increased at 24 and 48 hours and decreased at 168 hours. When the drugs were compared, it was found that the inhibition effect of aspirin on PGE(2) was more than that of rofecoxib. The results suggest that rofecoxib can be used during orthodontic treatment, but further study is recommended.