3,715 research outputs found

    Reliability of Digital Dental Cast Measures as Compared to Cone-Beam Computed Tomography for Analyzing the Transverse Dimension

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    The purpose of this study was to assess the consistency in diagnosing the transverse dimension on cone-beam computed tomography (CBCT) images as compared to digital dental models. The study consisted of 11 patients with posterior crossbite at the level of the first molar and 17 patients with no crossbite at the level of the first molar. 13 patients were male and 15 patients were female with an overall mean age of 13.6 years. Eight linear measurements and two angular measurements were made on CBCT images of the patients and six linear measurements were made on the corresponding digital dental casts. CBCT and model measurements were compared using One-Way Analysis of Variance (ANOVA) and Pearson correlation tests were used to seek relationships between the dental and skeletal measurements on CBCT. All ratios between maxillary and corresponding mandibular measurements were larger in non-crossbite patients than in crossbite patients. The central fossa (CF) was found to be the most representative and reliable tooth measurement in judging dental and skeletal transverse dimensions. A normative CF-CF ratio was determined to be equal to or greater than 1.10 for non-crossbite patients. High correlations were found between dental and skeletal measurements for non-crossbite patients with a CF-CF ratio equal to or greater than 1.10, but were not found for crossbite patients with a CF-CF ratio less than 1.10. In conclusion, CBCT scans may not provide additional diagnostic information as compared to dental models for non-crossbite patients. However, CBCT scans may be diagnostically beneficial for crossbite patients. Further studies with a larger sample size are needed to determine the validity of this study

    An overview of selected orthodontic treatment need indices

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    Orthodontics is a fast developing science as well as the field of medicine in general. The attempt of this book is to propose new possibilities and new ways of thinking about Orthodontics beside the ones presented in established and outstanding publications available elsewhere. Some of the presented chapters transmit basic information, other clinical experiences and further offer even a window to the future. In the hands of the reader this book could provide an useful tool for the exploration of the application of information, knowledge and belief to some orthodontic topics and questions

    Orthodontic treatment need and prevalence of malocclusions in the Orthodontic Unit of "Sapienza - University of Rome" : a six - year clinical experience

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    AIM The objective of this epidemiological survey was to investigate the dental-skeletal features of subjects attending the Public Dental Service in U.O.C. (Orthodontic Department of “La Sapienza University of Rome) and compare them with the existing body of evidence coming from other surveys. Accordingly, the Index of Orthodontic Treatment Need (I.O.T.N.) was employed, in order to achieve a common framework to allow the shaping of public health prevention practices. MATERIALS & METHODS A sample of 3491 subjects in the Orthodontic Department of “La Sapienza- University of Rome” (UOC) was evaluated with the adoption of I.O.T.N. to define malocclusion severity. RESULTS In the result analysis, it was observed that class II malocclusion was more frequent in the sample (40%), and a large part of the examined population also presented mandibular dental crowding (43%), increased overjet (41%), increased overbite (38%). Only 26,44% (20,17% IOTN 4; 6,27% IOTN 5) had strong need for orthodontic treatment. CONCLUSION The realization of epidemiologic investigations to establish priority for treatment need is therefore particularly useful, not only to estimate the prevalence of some clinical conditions in the observed population, but also to plan targeted interventions, such as interceptive and corrective therapies in growing children. CLINICAL SIGNIFICANCE These interventions could solve specific clinical situations and/or prevent their escalation. Only in this way it’s possible to avoid fragmenting the limited resources available, using them for patients with an objective need

    Condylar Hyperplasia: An Updated Review of the Literature

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    Condylar hyperplasia (CH) is a rare disorder characterized by excessive bone growth that almost always presents unilaterally, resulting in facial asymmetry. Classification of the different types of CH can differ depending on the authors. Correct diagnosis is critical in determining the proper treatments and timing. This paper is a review of the recent literature on the epidemiology, etiology, diagnosis, classification, and surgical treatments of CH

    Dimensional Changes of Upper Airway after Rapid Maxillary Expansion: A Prospective Cone-beam Computed Tomography Study

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    Introduction: The aim of this prospective study was to use cone-beam computed tomography to assess the dimensional changes of the upper airway in orthodontic patients with maxillary constriction treated by rapid maxillary expansion. Methods: Fourteen orthodontic patients (mean age, 12.9 years; range, 9.7-16 years) were recruited. The patients with posterior crossbite and constricted maxilla were treated with rapid maxillary expansion as the initial part of their comprehensive orthodontic treatments. Before and after rapid maxillary expansion conebeam computed tomography scans were taken to measure the retropalatal and retroglossal airway changes in terms of volume, and sagittal and cross-sectional areas. The transverse expansions by rapid maxillary expansion were assessed between the midlingual alveolar bone plates at the maxillary first molar and first premolar levels. The measurements of the before and after rapid maxillary expansion scans were compared by using paired t tests with the Bonferroni adjustment for multiple comparisons. Results: After rapid maxillary expansion, significant and equal amounts of 4.8 mm of expansion were observed at the first molar (P 5 0.0000) and the first premolar (P 5 0.0000) levels. The width increase at the first premolar level (20.0%) was significantly greater than that at the first molar level (15.0%) (P 5 0.035). As the primary outcome variable, the cross-sectional airway measured from the posterior nasal spine to basion level was the only parameter showing a significant increase of 99.4 mm2 (59.6%) after rapid maxillary expansion (P 5 0.0004). Conclusions: These results confirm the findings of previous studies of the effect of rapid maxillary expansion on the maxilla. Additionally, we found that only the cross-sectional area of the upper airway at the posterior nasal spine to basion level significantly gains a moderate increase after rapid maxillary expansion

    Maxillary orthodontic expansion assisted by unilateral alveolar corticotomy and low-level laser therapy: a novel approach for correction of posterior unilateral cross-bite in adults

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    Introduction: The treatment of a true unilateral posterior crossbite often requires asymmetric maxillary expansion; however, this is challenging to achieve with conventional expansion methods because of several biomechanical limitations. In this paper, we introduce a new protocol for the treatment of a unilateral posterior crossbite in adults based on maxillary orthodontic expansion assisted by corticotomy and low-level laser therapy (LLLT) performed on the crossbite side. Methods: The study sample included 15 adults (8 females, 7 males) affected by a true unilateral posterior crossbite, with a mean age of 21.6 ± 3.1 years at the at the beginning of treatment. After the application of orthodontic appliances (palatal expander and self-ligating brackets), corticomy was performed at the buccal aspect of the crossbite side while LLLT was monthly administered up to the correction of the crossbite. The efficacy of the technique was evaluated through measurements performed on maxillary digital models. Results: All subjects reported successful correction of the posterior unilateral crossbite, and functional occlusion was achieved as well. The average expansion was greater at the crossbite side compared to the unaffected side and such difference was significant at the levels of first premolars (P < 0.05), second premolars (P < 0.05) and first molars (P < 0.05). Conclusion: Orthodontic maxillary expansion assisted by unilateral corticotomy and LLLT was effective in the treatment of the true unilateral crossbite

    Predictability of Maxillary Dentoalveolar Expansion Using Clear Aligners in Different Types of Crossbites

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    The aim of this study was to determine the efficacy and predictability of maxillary dentoalveolar expansion clear aligners in unilateral, bilateral, and single-tooth types of crossbite. This prospective analytical study enrolled adults with dentoalveolar posterior crossbite. Orthoanalyzerℱ 1.7 software was used to analyze stl files of digital models before treatment (T1), predicted post-treatment outcome (T2), and observed outcome (T3). Changes in intercanine width, first and second interpremolar widths, and intermolar width were compared using a mixed ANOVA model for repeated measures (α = 0.05). The study included 46 patients aged 20–60 years, 15 with unilateral, 15 bilateral, and 16 single-tooth crossbite. In all crossbite groups, expansion was largest at the second premolar level (unilateral: 2.54 mm; bilateral:, 4.86 mm; single-tooth: 3.41 mm) (ANOVA p < 0.001) and smallest at the canine level. Expansion predictability was 90% at the first premolar level in the single-tooth crossbite group, 86% at the second premolar level in the bilateral crossbite group, and 79% at the second premolar level in the unilateral crossbite group. No significant difference was found between the predicted and observed expansion in any crossbite group. Dentoalveolar expansion using differential anchorage techniques with clear aligners is highly predictable, although the treatment plan should consider overcorrection of the expansion movement to achieve the planned outcome.Depto. de Especialidades ClĂ­nicas OdontolĂłgicasFac. de OdontologĂ­aTRUEpu

    Changes in the midpalatal and pterygopalatine sutures induced by micro-implant-supported skeletal expander, analyzed with a novel 3D method based on CBCT imaging.

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    BackgroundMini-implant-assisted rapid palatal expansion (MARPE) appliances have been developed with the aim to enhance the orthopedic effect induced by rapid maxillary expansion (RME). Maxillary Skeletal Expander (MSE) is a particular type of MARPE appliance characterized by the presence of four mini-implants positioned in the posterior part of the palate with bi-cortical engagement. The aim of the present study is to evaluate the MSE effects on the midpalatal and pterygopalatine sutures in late adolescents, using high-resolution CBCT. Specific aims are to define the magnitude and sagittal parallelism of midpalatal suture opening, to measure the extent of transverse asymmetry of split, and to illustrate the possibility of splitting the pterygopalatine suture.MethodsFifteen subjects (mean age of 17.2&nbsp;years; range, 13.9-26.2&nbsp;years) were treated with MSE. Pre- and post-treatment CBCT exams were taken and superimposed. A novel methodology based on three new reference planes was utilized to analyze the sutural changes. Parameters were compared from pre- to post-treatment and between genders non-parametrically using the Wilcoxon sign rank test. For the frequency of openings in the lower part of the pterygopalatine suture, the Fisher's exact test was used.ResultsRegarding the magnitude of midpalatal suture opening, the split at anterior nasal spine (ANS) and at posterior nasal spine (PNS) was 4.8 and 4.3&nbsp;mm, respectively. The amount of split at PNS was 90% of that at ANS, showing that the opening of the midpalatal suture was almost perfectly parallel antero-posteriorly. On average, one half of the anterior nasal spine (ANS) moved more than the contralateral one by 1.1&nbsp;mm. Openings between the lateral and medial plates of the pterygoid process were detectable in 53% of the sutures (P&nbsp;&lt;&nbsp;0.05). No significant differences were found in the magnitude and frequency of suture opening between males and females. Correlation between age and suture opening was negligible (R 2 range, 0.3-4.2%).ConclusionsMidpalatal suture was successfully split by MSE in late adolescents, and the opening was almost perfectly parallel in a sagittal direction. Regarding the extent of transverse asymmetry of the split, on average one half of ANS moved more than the contralateral one by 1.1&nbsp;mm. Pterygopalatine suture was split in its lower region by MSE, as the pyramidal process was pulled out from the pterygoid process. Patient gender and age had a negligible influence on suture opening for the age group considered in the study

    Self correction of anterior crossbite: a case report

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    A 9-year-old Chinese boy presented with an anterior crossbite, no treatment was performed at that time because the incisors have open root apices. The crossbite self-corrected after one year. This case demonstrated that an anterior crossbite may self-correct without treatment