Mandibular dental arch changes with active self-ligating brackets combined with different archwires.

OBJECTIVE: The aim was to compare mandibular arch and incisor inclinational changes by comparing active self-ligating brackets used with different forms of archwires with a control group in nonextraction cases. MATERIALS AND METHODS: The sample of 50 patients with Class I malocclusion was divided into three groups: Group I was treated with active self-ligating brackets (Nexus, Ormco/Orange, CA, USA) used with Damon arch form copper nickel-titanium (Cu-NiTi) and stainless steel (SS) wires; Group II was treated with interactive self-ligating bracket system (Empower, American Orthodontics, Sheboygan, Wis, USA) used with standard Cu-NiTi and SS wires; and Group III was treated with Roth prescribed conventional brackets (Forestadent, Pforzheim, Germany) with standard Cu-NiTi and SS wires which was designed as a control group. Changes in dimension of mandibular arch and inclination of incisors were assessed on dental models and lateral cephalometric radiographs at pretreatment (T1) and posttreatment (T2) periods. Paired-t test and one-way analysis of variance were used to perform intragroup and intergroup comparisons, respectively. RESULTS: In all groups, an average increase of transversal distances occurred from pretreatment to the posttreatment period (P < 0.05). However, mandibular arch length increase was significantly different among the Groups I-III (P = 0.008) and I-II (P = 0.006). No significant intergroup difference was found with regard to incisor inclinational changes. CONCLUSIONS: Bracket type had no significant effect on the mandibular dimensional or incisor inclination changes. Besides this, archwire type had only little effect on the treatment results as active self-ligating bracket with Damon archwires increased mandibular arch length greater than other groups.

Alignment of transposed mandibular lateral incisor and canine using removable appliances.

The purpose of this paper was to present the management of a rarely encountered transposition anomaly involving the mandibular permanent lateral incisor and the canine. In the literature, the treatment of this type of anomaly involves fixed orthodontic appliances. The treatment of the present case, however, was performed with removable appliances. Transposition of the permanent mandibular right lateral incisor and the permanent mandibular right canine was detected in a 12 year old girl. The primary mandibular right canine was extracted to enable the distal movement of the permanent lateral incisor by the eruption force of the permanent canine. The transposed teeth were then aligned in the arch by using removable appliances. The forms of the teeth were changed with each other with composite restorations.

Tensile bond strength of ceramic orthodontic brackets bonded to porcelain surfaces.

The aim of this study was to compare various surface treatment methods to define the procedure that produces adequate bond strength between ceramic brackets and porcelain. The specimens used in this study, 60 porcelain tabs, were produced by duplication of the labial surface of a maxillary first premolar. The 6 different preparation procedures tested were: (1) sandblasting with 50 microm aluminum oxide in a sandblasting device, (2) application of silane to the porcelain and the bracket base, (3) sandblasting followed by application of silane, (4) acid etching with 9.6% hydrofluoric acid, (5) acid etching with 9.6% hydrofluoric acid followed by application of silane, and (6) sandblasting followed by application of 4-Meta adhesive. The ceramic brackets were bonded with no-mix orthodontic bonding material. A bonding force testing machine was used to determine tensile bond strengths at a crosshead speed of 0.5 mm per second. The results of the study showed that porcelain surface preparation with acid etching followed by silane application resulted in a statistically significant higher tensile bond strength (P < .05). Sandblasting the porcelain surface before silane treatment provided similar bond strengths, but sandblasting or acid etching alone were less effective. Silane application was recommended to bond a ceramic bracket to the porcelain surface to achieve bond strengths that are clinically acceptable.

The effect of enamel air abrasion on the retention of bonded metallic orthodontic brackets.

The purpose of this study was to compare the conventional acid-etch technique with an air abrasion surface preparation technique. Eighty freshly extracted noncarious human premolar teeth were randomly divided into the following 4 groups: (1) acid etched with 37% phosphoric acid for 15 seconds (Express Dental Products, Toronto, Canada), (2) sandblasted with 50 mu aluminum oxide by a microetcher (Danville Engineering Inc, Danville, Calif), (3) polished with pumice followed by acid etched with 37% phosphoric acid for 15 seconds, (4) sandblasted with 50 mu aluminum oxide by a microetcher followed by acid etched with 37% phosphoric acid for 15 seconds. All the groups had stainless steel brackets (Dentaurum, Standard Edgewise) bonded to the buccal surface of each tooth with no-mix adhesive (Express Dental Products, Toronto, Canada). A Lloyd testing machine (Lloyd Instrument LR 30K; Segensworth West, Foreham, UK) was used to determine tensile bond strengths at a crosshead speed of 0.5 mm/sec. The mean bond strength values of these are as follows: the only sandblasted group was 38.05 +/- 9.93 N; the only acid-etched group was 62.72 +/- 11.44 N; the group that was polished with pumice followed by acid etched was 69.78 +/- 14.87 N; and the group that was sandblasted followed by acid etched was 89.31 +/- 13. 34 N. The statistical analysis was done by an analysis of variance and Scheff¿e test. The sandblasting followed by acid etching group had significantly higher bond strength values when compared to the other 3 groups. This study showed that sandblasting should be followed by acid etching to produce enamel surfaces with comparable bond strength. The current findings indicate that enamel surface preparation using sandblasting with a microetcher alone results in a significantly lower bond strength and should not be advocated for clinical use as an enamel conditioner.

The effect of first premolar extraction on vertical dimension.

The purpose of this study was to evaluate the vertical changes occurring in Class I patients treated orthodontically with first premolar extraction and to compare these changes with those occurring in Class I patients treated orthodontically without extractions. Records of 40 Class I nonextraction cases (24 girls, 16 boys) and 40 Class I maxillary and mandibular first premolar extraction cases (23 girls, 17 boys) were obtained. The pretreatment and posttreatment cephalograms were digitized, and 6 linear and 8 angular cephalometric measurements were selected to evaluate vertical changes. Evaluation of the treatment results of the extraction and nonextraction cases showed that the vertical changes occurring after the extraction of maxillary and mandibular first premolars were not different than those occurring in the nonextraction cases.

Evaluation of Ricketts' long-range growth prediction in Turkish children.

This study was conducted to evaluate Ricketts' long-range growth prediction in Turkish children. Cephalometric analysis was conducted at baseline and 7 years for 40 children (20 girls, 20 boys) who received no orthodontic treatment. Ricketts' long-range prediction was performed from baseline cephalograms and compared with actual growth 7 years later. Twenty-one cephalometric (12 angular and 9 linear) parameters were measured on actual and predicted tracings. The Pearson correlation coefficient was used to evaluate relationships between the "predicted" and "actual" measurements. Analysis was conducted on pooled data (males and females) and data by sex. There was a higher level of correlation for growth prediction in girls. Data indicate predictability in boys was greater for maxillary mandibular growth parameters. It was concluded that Ricketts' long-range growth prediction may be helpful in improving treatment planning. Further work on accurate soft tissue and hard tissue growth prediction is indicated.

Early orthopedic treatment for Class III skeletal pattern.

An eight-year-old female, Class III due to maxillary retrusion with brachyfacial growth pattern was treated with a functional regulator appliance (FR-3). By initiating treatment at an early age, developing skeletal imbalances were corrected. At postretention six years she had balanced profile and stable functional occlusion.

Combined endodontic-orthodontic and prosthodontic treatment of fractured teeth. Case report.

A case history of a 10 year old patient who accidentally injured his maxillary left central incisor is presented. The fracture of the crown extended about 4 mm below the crest of the alveolar bone. After pulpectomy and root canal therapy, a screw was cemented into the canal of the incisor. By means of a removable orthodontic appliance, the fractured tooth was extruded and the fracture line was brought above the level of the alveolar bone. The tooth was then restored with a veneer crown over a post core. A tooth that would have been extracted routinely was thus saved and restored through the use of a collaborative approach.

Early treatment of posterior and anterior crossbite in a child with bilaterally constricted maxilla: report of case.

A case report of a young patient with anterior and bilateral posterior crossbite was presented. She was severely brachyfacial with a mild Class III malocclusion due to slight maxillary retrusion. Early orthodontic therapy using a simple, removable, maxillary expansion appliance provided the patient with a stable, functional occlusion and good esthetics.

Treatment of a Class I malocclusion with maxillary insufficiency and anterior crossbite: a case report.

A patient who had a Class I malocclusion with maxillary insufficiency and anterior crossbite is described. A 14-year-old girl with limited growth potential had an impacted permanent maxillary canine. The permanent mandibular first molars had been extracted previously. Treatment included extraction of the maxillary first premolars and comprehensive edgewise orthodontic therapy.

Orthodontic management of a horizontally positioned maxillary lateral incisor.

A case report of a patient who had lost her maxillary permanent left central incisor, left cuspid and left first premolar teeth due to a cyst operation, is presented. The maxillary permanent left lateral incisor was in horizontal position high in the vestibule. She was treated with removable and fixed orthodontic appliances. The lateral incisor was uprighted and brought into its normal position in the dental arch. For aesthetics and function missing teeth were replaced with a specially designed prosthesis.

Palatal expansion with a total denture.

A case report of a pediatric patient who had posterior crossbite is presented. She was diagnosed with hypophosphatasia and had primary tooth loss. A total denture was constructed for aesthetics and function. For the correction of posterior cross bite, a palatal screw was placed in the upper denture. The upper archs successfully expanded to a proper relationship.

Retention of orthodontic bands with three different cements.

In 1878, zinc phosphate cement was introduced as a dental material and used to cement orthodontic bands. The prevalence of enamel decalcification beneath orthodontic bands has indicated the need for a fluoride-releasing orthodontic luting cement. The purpose of this study was to compare the retentive bond strengths of orthodontic bands cemented individually with zinc polycarboxylate, glass ionomer and zinc phosphate cement adhesives. Forty-eight extracted human molar teeth were embedded in resin blocks and each was randomly assigned to one of the three cement groups. Adapted bands were cemented by using hand pressure and a band seater. The cemented teeth were then put in synthetic saliva at 37 degrees C for twenty-four hours. The force required to fracture the cement bond was used as a measure of cement retention. Using an Instron universal testing machine, a tensile load was applied to each cemented band. The Kruskal-Wallis one-way analysis of variance test revealed no significant differences (p > 0.05) among the retentive strengths of the three cements. Both the zinc polycarboxylate and the glass ionomer cements tested were found to be suitable as orthodontic luting agents. In addition, the ability to bond to enamel and stainless steel and to leach fluoride make the glass ionomer cement an ideal orthodontic cement.

Correction of Class II, division 1, malocclusion with the use of an activator appliance: a case report.

This article describes the use of an activator appliance to treat a Class II, division 1, malocclusion in a child in the mixed-dentition phase. The correction of Class II, division 1, malocclusions can be achieved by careful case selection of a motivated patient with a favorable growth pattern.

Congenitally missing teeth: an alternative approach for space closure.

While closing the large bilateral spaces caused by either the extraction of molar teeth or the congenitally absence of premolar in the lower arch, the important point is to move the teeth bodily and avoid tipping as much as possible. For this purpose an alternative orthodontic treatment approach can be the use of Lingual Functional Appliance which mesially moves the mandibular molar teeth bodily and also shortens the fixed orthodontic treatment time.