World journal of orthodontics最新文献

Aim: To determine with a cross-sectional study the prevalence of orthodontic treatment need using the Dental Aesthetic Index (DAI).

Subjects and methods: Using a stratified sampling method in private and public schools in Isfahan, Iran, 748 subjects were examined and divided into three age groups: 11 to 14, 14 to 17, and 17 to 20 years (355 females and 393 males, 15.11 ± 2.23 years), including 20 subjects with history of orthodontic treatment. DAI scores were recorded in those without history of orthodontic treatment (n=728, 340 females and 388 males). The proportions of subjects within sexes needing treatment, as defined by having DAI scores of at least 31, were compared using the chi-square test. The chi-square test was also used to test for any difference for DAI treatment categories in different age groups and also to test for sex dimorphism.

Results: The mean DAI score was 26.14 (SD=7.64) points (95% CI, 26.60 to 26.72). On the whole, 54.5% showed no need or slight need for treatment. In 23.6%, the need for treatment was elective. However, in 11.0%, treatment was highly desirable and 10.9% showed very severe malocclusions and treatment was mandatory. There was a significant difference between sexes with regard to DAI treatment need categories (chi-square=10.10, df=3, P<.05). There was no significant difference between different age groups with regard to DAI treatment categories (P>.05).

Conclusion: According to our findings, 21.8% of the evaluated Iranian school children in our sample had a DAI score above or equal to 31 points, suggesting highly desirable or mandatory orthodontic treatment need.

Aim: Orthodontic need assessment is instrumental for dental treatment planning. The objective of this examination was to evaluate the orthodontic treatment need of students in Shiraz, Iran, using the Dental Aesthetic Index (DAI) and to assess the relationship between DAI and sociodemographic variables.

Methods: Using random cluster sampling, 1,818 pupils (965 male and 853 female) 14 to 18 years of age without any history of orthodontic treatment were selected. Information was gathered using a questionnaire, including demographics such as sex, family size, and parents' education. Orthodontic assessments were performed by two orthodontists over 2 months. The data were analyzed with chi-square and t tests.

Results: Many of the subjects (48.3%) had no need for orthodontic treatment. About one-fifth of the population (21%) had intense-to-disabling malocclusions, and 8.4% had disabling malocclusion with compulsory treatment needs. The study showed a close relationship between sex and malocclusion.

Conclusion: The study showed that Iranian youth in Shiraz had better dental appearances and less orthodontic treatment need than some populations (Japanese, Caucasian and Native Americans, and Caucasian Australians) but worse than Chinese, Spanish, and Nigerian populations. It might be possible to relate the difference to genetics, cultural differences, and growth.

Aim: To test the hypothesis that the faces of patients with a severe Class III are contemplated differently from and assessed more negatively than skeletal Class I patients in direct face-to-face interaction.

Method: The eye movements of 24 randomly recruited evaluators were analyzed with a noninvasive, infrared high-speed camera while looking at 18 standardized frontal photographs of adult orthognathic Class III patients and 18 photographs of adults with skeletal Class I relationships as controls. Additionally, all images were assessed for appearance, symmetry, and facial expression.

Results: The Class III patients were rated significantly more negatively in terms of appearance, symmetry, and facial expression than the Class I individuals. The eye movement data revealed that orthognathic patients were appraised differently from the Class I individuals, with fewer fixations in the face center, especially around the mouth.

Conclusion: Skeletal Class III patients were characterized as less attractive than Class I individuals. Faces of Class III patients were visually perceived with different eye movements. These differences in visual perception are described for the first time in the present study. Although they were small, they are an indication of an objectively different perception of faces that are rated subjectively as less attractive and more asymmetric and exhibiting a more negative expression.

Esthetic orthodontic appliances continue to appeal to more patients, which results in objections to extraction spaces that remain for several months during orthodontic therapy. This has led orthodontists to design temporary pontics that fill extraction sites and that can be reduced as the spaces close. This report describes a simple, efficient, and expeditious technique for making such pontics.

Aim: To evaluate the shear bond strength (SBS) and fracture mode of amorphous calcium phosphate (ACP)-containing and conventional glass-ionomer cement (GIC) for band fixation.

Methods: Sixty extracted human third molars were embedded in acrylic resin blocks, leaving the buccal surface of the crowns parallel to the base of the molds. The teeth were randomly divided into two groups containing 30 teeth each. GIC (group 1, Ketac-Cem) or ACP-containing orthodontic cement (group 2, Aegis-Ortho) was applied onto microetched strip band material (4.0 × 3.8 mm), which was then attached to the tooth surfaces. With a universal testing machine, each cemented band strip was shear mode loaded until failure. Thereafter, all teeth and band strips were examined under 10× magnification. The remaining cement was assessed with a modified Adhesive Remnant Index (ARI). The SBS data were analyzed using the t test and the fracture modes by the chi-square test.

Results: There was no significant difference between the bond strength of group 1 (GIC, mean: 28.9 ± 15.2 MPa) and group 2 (ACP-containing cement, mean: 26.3 ± 11.8 MPa). The fracture modes differed significantly between the two groups (P<.01).

Conclusion: Both groups had a similar level of SBS. The fracture sites of the ACP-containing cement were predominantly in the enamel-cement interface.

The present article illustrates a treatment option for managing the skeletal Class II malocclusion complicated by a deep bite and short face in an adult and emphasizes the limitations of such an approach and its potential complications. The patient had an inadequate tooth display upon smiling and a deep lower curve of Spee. Treatment consisted of a double jaw surgery with a maxillary three-piece LeFort to expand, downgraft, and advance the maxilla and a bilateral sagittal split osteotomy to advance the mandible. Treatment was staged so that the leveling of the mandibular arch was completed postsurgically by extrusion of the mandibular buccal segments. During surgery, the mandible was rotated clockwise at the osteotomy site to bring the chin down. This treatment approach resulted in a dramatic increase in the lower facial height, as well as an improvement in skeletal and occlusal relationships, with a much improved tooth display upon smiling, despite the few complications that occurred.

Aim: To find the cephalometric norms for Palestinian population according to Steiner cephalometric analysis.

Methods: Lateral cephalograms of 76 dental students (51 females and 25 males, mean age 20.4 ± 2.1 years) were collected from their files at the American University in Jenin, Palestine. They were scanned and analyzed following Steiner measurements. Means and standard deviations for all variables were calculated. Differences between the mean of the variables for both sexes were calculated using the independent t test.

Results: Females had a smaller interincisal angle, more proclined mandibular incisors, and a shorter anterior cranial base than males in the Palestinian population.

Conclusion: When the Palestinian sample population was compared to Steiner norms, similar skeletal patterns were found, but the anterior teeth were more proclined and protruded.

Aim: To evaluate the effects of three adhesion boosters--All-Bond 2, Enhance LC, and Ortho Solo--on the shear bond strength of new and rebonded (previously debonded) brackets.

Methods: One hundred new and 100 sandblasted debonded brackets were bonded to 200 extracted human premolars and divided into eight groups.

Results: The new brackets/Ortho Solo group yielded the highest bond strength, followed by the new brackets/All-Bond 2 and the new brackets/Enhance LC groups. During rebonding, Ortho Solo improved the bond strength significantly; however, All-Bond 2 and Enhance LC did not.

Conclusion: (1) Bond strength is significantly improved when new brackets are bonded with an adhesion booster; (2) without any adhesion booster, sandblasted rebonded brackets yield a significantly lower bond strength than new brackets; (3) Enhance LC failed to improve the bond strength of rebonded brackets; (4) Ortho Solo increased the bond strength of rebonded brackets significantly; and (5) brackets rebonded with Ortho Solo yielded comparable bond strength as new brackets without any adhesion booster.