Elastic activator for treatment of open bite.
(1/50)
This article presents a modified activator for treatment of open bite cases. The intermaxillary acrylic of the lateral occlusal zones is replaced by elastic rubber tubes. By stimulating orthopaedic gymnastics (chewing gum effect), the elastic activator intrudes upper and lower posterior teeth. A noticeable counterclockwise rotation of the mandible was accomplished by a decrease of the gonial angle. Besides the simple fabrication of the device and uncomplicated replacement of the elastic rubber tubes, treatment can be started even in mixed dentition when affixing plates may be difficult. (+info)
An unusual case of talon cusp on geminated tooth.
(2/50)
A rare case of talon cusp on geminated permanent central incisor is described. These developmental anomalies cause clinical problems including unsightly dental appearance, occlusal interference, displacement of the affected tooth, attrition, periodontopathy, irritation of the tongue, loss of space and malocclusion. Clinical and radiographic characteristics of these anomalies and modes of treatment are presented. Recognition of this condition and early diagnosis are important to avoid complications. (+info)
Interdisciplinary approaches to adult orthodontic care.
(3/50)
The orthodontic treatment of adult patients is most frequently just one component of a more complex treatment involving several dental disciplines. This report discusses the potential problems related to the establishment of a treatment plan and the necessity for the patient's full acceptance, and understanding of the pros and cons related to different treatment approaches. In addition, the case report underlines the importance of a well-defined treatment goal. We have illustrated the team approach and the treatment principles in this combined perio-, ortho-, and prosthodontic patient. (+info)
Clinical evaluation of the centre of resistance of the upper incisors during retraction.
(4/50)
The aim of this study was to evaluate the movement of anterior teeth during retraction with a force applied through the assumed centre of resistance (CRe).Twenty-two subjects with a Class I or II malocclusion were included. Each subject had the two upper first premolars extracted, resulting in a symmetrical extraction space of at least 3 mm between the upper laterals and canines. The force was applied through the assumed CRe, located 9 mm gingival to the lateral tooth bracket. To examine the type of anterior tooth movement, 10 parameters were measured. A Wilcoxon test was used to determine the differences between pre- and post-retraction values, and a Mann-Whitney U-test to determine the mean differences between groups. In spite of the force application through the CRe, tipping of the anterior teeth was observed in 19 subjects and parallel movement in three patients. Consequently, the subjects were divided into two groups according to the location of the centre of rotation (CRo). In group 1 (nine cases), the CRo was located coronal to the root apex, and in group 2 (13 cases), apical to the root apex. Both groups showed a significant decrease in inclination (P < 0.01) and posterior crown movement (P < 0.01 for group 1 and P < 0.001 for group 2) of the anterior teeth. A significant posterior movement of the root apex was observed in group 2 (P < 0.001). Significant differences were found between the groups for anterior tooth inclination (P < 0.05) and root apex movement (P < 0.001). The reasons for these differences could not be conclusively determined. Even though experimental studies provide information regarding CRe location, factors such as bone support, root morphology and incisor inclination should be taken into consideration. The observation of tooth movement occurring during treatment and changes in treatment mechanics would be helpful in obtaining desired tooth movement. (+info)
Prevalence and distribution by gender of occlusal characteristics in a sample of Italian secondary school students: a cross-sectional study.
(5/50)
The aim of this study was to describe the prevalence and distribution, by gender, of occlusal traits in a sample of Italian students aged 11-14 years (mean 13 +/- 1 years). Using standardized and validated recording criteria, a single operator measured the overjet, overbite, open bite, anterior and posterior crossbites, crowding, coincidence of the upper and lower midlines, and diastema, in 810 secondary school students (53.6 per cent males). Chi-square, t-test statistics, and odds ratios (ORs) with 95 per cent confidence intervals (CI) were used to investigate the relationship between gender and malocclusion characteristic. Logistic regression was used to further analyse the independent association between gender and each outcome measure. Ninety-three per cent of the subjects showed at least one occlusal trait, with one or two anomalies recorded in 63 per cent of children. The prevalence of occlusal traits ranged from 1.1 (negative overjet) to 54 per cent (upper and lower midlines not coincident). Males were more likely than females to show both an increased overbite and an increased overjet, although the latter result was not confirmed by logistic regression (P = 0.05). Multivariate analysis showed a negative association between overbite and misalignment of the lower incisors and lack of coincidence of the upper and lower midlines, whereas subjects with an increased overbite were more likely to have an increased overjet (all P < 0.01). Further studies are required in order to further clarify these findings and to provide accurate estimates of the orthodontic treatment need in Italian adolescents. (+info)
Localized sequential use of resilient lining to generate orthodontic force in thermoformed active removable appliances.
(6/50)
A new modality of orthodontic treatment based on the thermoformed appliance was developed and trialled clinically. A light-cured resilient lining material commonly used for denture relining was placed locally and sequentially in thermoformed appliances to generate orthodontic forces. The new method appeared to be effective. All the presented cases showed substantial improvement in dental alignment. A number of orthodontic movements were demonstrated. Localized use of resilient lining in thermoformed orthodontic appliances appeared to be a promising alternative to other thermoformed active removable appliance (TARA) treatments. Further studies are required to optimize the procedures and explore its full potential. (+info)
Maxillary midline diastema: a case report involving a combined orthodontic/maxillofacial approach.
(7/50)
This paper presents an orthodontic case of a large (14.5 mm) maxillary midline diastema that was related to the presence, and subsequent removal of 2 median maxillary supernumerary teeth and resulting bone loss. A combined orthodontic and maxillofacial approach involving bone grafting and fixed appliances was used to close the space. This episode of care was organized as interceptive treatment during development of the permanent dentition. (+info)
Sprouty genes control diastema tooth development via bidirectional antagonism of epithelial-mesenchymal FGF signaling.
(8/50)
Unlike humans, who have a continuous row of teeth, mice have only molars and incisors separated by a toothless region called a diastema. Although tooth buds form in the embryonic diastema, they regress and do not develop into teeth. Here, we identify members of the Sprouty (Spry) family, which encode negative feedback regulators of fibroblast growth factor (FGF) and other receptor tyrosine kinase signaling, as genes that repress diastema tooth development. We show that different Sprouty genes are deployed in different tissue compartments--Spry2 in epithelium and Spry4 in mesenchyme--to prevent diastema tooth formation. We provide genetic evidence that they function to ensure that diastema tooth buds are refractory to signaling via FGF ligands that are present in the region and thus prevent these buds from engaging in the FGF-mediated bidirectional signaling between epithelium and mesenchyme that normally sustains tooth development. (+info)