RESUMO
PURPOSE: The proper angle of miniscrew insertion is important for cortical anchorage, patient safety, and biomechanical control. The purposes of this study are to report the alveolar process thickness and inter-radicular space in the posterior region of the mandible, to assess the impact of different miniscrew insertion angle protocols, and to identify differences between the genders or types of malocclusion. MATERIALS AND METHODS: In this retrospective study, 100 individuals were selected for orthodontic treatment at a radiology clinic. Cone-beam computed tomography data were imported into 3-dimensional software. The predictor variable was the location in the mandible and insertion angle. The demographic variables collected included age, gender, and malocclusion (Angle Classes I and II). The primary outcome variables were bone thickness and inter-radicular space. The inter-radicular spaces were evaluated 5 mm from the cement-enamel junction. The bone thicknesses were taken at 45°, 60°, and 90° in relation to the alveolar ridge, simulating a miniscrew insertion. These factors were evaluated for sexual dimorphism and malocclusion (Angle Classes I and II). Sexual dimorphism and malocclusion were evaluated with t tests. To compare the inter-radicular space and the thickness of bone between areas, an analysis of variance for repeated measures was used. RESULTS: The sample was composed of 100 patients with a mean age of 17.4 ± 6.74 years. There were 61 female and 39 male patients and 60 Class I and 40 Class II molar relationships. The inter-radicular space ranged from 2.46 to 3.31 mm, and alveolar bone thickness ranged from 8.01 to 13.77 mm. The thickness tended to decrease with the increase in insertion angle from 45° to 90°. No significant differences between the genders or types of malocclusion were found. CONCLUSIONS: The results of this study suggest that the safest areas for the placement of miniscrews are between the first and second premolars and between the first and second molars, regardless of the angle of insertion.
Assuntos
Parafusos Ósseos , Mandíbula/anatomia & histologia , Ortodontia , Adolescente , Adulto , Criança , Tomografia Computadorizada de Feixe Cônico , Humanos , Estudos Retrospectivos , Adulto JovemRESUMO
OBJECTIVE: To assess the upper airway (UAW) total volume (TV), the nasopharyngeal narrowest area (NNA), and the oropharyngeal narrowest area (ONA) in patients with bronchial asthma. MATERIALS AND METHODS: The sample consisted of 52 patients divided into two groups: the control group (n â=â 26; mean age â=â 14.85 years), which consisted of patients not suffering from bronchial asthma; and the asthmatic group (n â=â 26; mean age â=â 16.65 years), which consisted of patients with bronchial asthma. To assess UAW-related variables (TV, NNA, and ONA), cone-beam computed tomography scans of the patients were evaluated by means of the Dolphin Imaging software 11.5. All measurements were repeated after 30 days, and the results were submitted to reliability tests by means of the intraclass correlation coefficient and the Bland-Altman agreement test. The values obtained for TV, NNA, and ONA for each group were compared by using Student's t-test for independent samples (5% level of significance). RESULTS: The results showed that the groups were matched concerning gender, cephalometric characteristics, and type of malocclusion. The asthmatic group had significantly lower TV (P â=â .01) and ONA (P â=â .007) than the control group. However, no significant difference was observed for NNA between the groups (P â=â .54). CONCLUSIONS: Bronchial asthma may be a determining factor for the reduction of UAW dimensions, as patients with asthma showed significant reductions in TV and ONA dimensions.
Assuntos
Asma/diagnóstico por imagem , Imageamento Tridimensional/métodos , Nasofaringe/diagnóstico por imagem , Orofaringe/diagnóstico por imagem , Adolescente , Asma/patologia , Estudos de Casos e Controles , Cefalometria/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Má Oclusão Classe I de Angle/diagnóstico por imagem , Má Oclusão Classe II de Angle/diagnóstico por imagem , Mandíbula/diagnóstico por imagem , Maxila/diagnóstico por imagem , Osso Nasal/diagnóstico por imagem , Nasofaringe/patologia , Tamanho do Órgão , Orofaringe/patologia , Faringe/diagnóstico por imagem , Faringe/patologia , Sela Túrcica/diagnóstico por imagemRESUMO
Abstract Objective: To assess the upper airway (UAW) total volume (TV), the nasopharyngeal narrowest area (NNA), and the oropharyngeal narrowest area (ONA) in patients with bronchial asthma. Materials and Methods: The sample consisted of 52 patients divided into two groups: the control group (n â=â 26; mean age â=â 14.85 years), which consisted of patients not suffering from bronchial asthma; and the asthmatic group (n â=â 26; mean age â=â 16.65 years), which consisted of patients with bronchial asthma. To assess UAW-related variables (TV, NNA, and ONA), cone-beam computed tomography scans of the patients were evaluated by means of the Dolphin Imaging software 11.5. All measurements were repeated after 30 days, and the results were submitted to reliability tests by means of the intraclass correlation coefficient and the Bland-Altman agreement test. The values obtained for TV, NNA, and ONA for each group were compared by using Student's t-test for independent samples (5% level of significance). Results: The results showed that the groups were matched concerning gender, cephalometric characteristics, and type of malocclusion. The asthmatic group had significantly lower TV (P â=â .01) and ONA (P â=â .007) than the control group. However, no significant difference was observed for NNA between the groups (P â=â .54). Conclusions: Bronchial asthma may be a determining factor for the reduction of UAW dimensions, as patients with asthma showed significant reductions in TV and ONA dimensions.
RESUMO
OBJECTIVES: The objective of this study was to elucidate the changes occurring in the temporomandibular joint (TMJ) after surgical mandibular advancement with different fixation techniques: bicortical screws (rigid fixation) and miniplates (semi-rigid fixation). STUDY DESIGN: Eighteen minipigs were equally and randomly divided into 3 groups: Group I (control), nonoperated animals; Group II, animals submitted to surgical advancement surgery and osteosynthesis by bicortical screws; and Group III, animals submitted to surgical advancement surgery and osteosynthesis by miniplates. Four months after the surgeries, the presence of interleukin (IL)-6 and IL-10 in synovial fluid samples was assessed in ELISA experiments. TMJs were histologically prepared. RESULTS: Higher levels of IL-10 (P = .0436) were found for Group II. Descriptive histological analysis was compatible with the ELISA findings. CONCLUSIONS: Rigid fixation evokes more pronounced signs of bone remodeling in the TMJ, whereas malleable fixation promotes a more intense inflammatory activity. Therefore, rigid fixation seems to transmit a higher impact of postoperative masticatory forces to the TMJ.
Assuntos
Técnicas de Fixação da Arcada Osseodentária/instrumentação , Mandíbula/cirurgia , Avanço Mandibular/métodos , Articulação Temporomandibular/fisiopatologia , Análise de Variância , Animais , Placas Ósseas , Remodelação Óssea , Parafusos Ósseos , Análise do Estresse Dentário , Ensaio de Imunoadsorção Enzimática , Mediadores da Inflamação/análise , Interleucina-10/análise , Interleucina-6/análise , Masculino , Côndilo Mandibular/fisiologia , Distribuição Aleatória , Suínos , Porco Miniatura , Líquido Sinovial/químicaRESUMO
INTRODUCTION: In this study, we investigated whether it is possible to orthodontically move a tooth into an adjacent bone defect previously filled with xenogenic grafting material, with emphasis on the reactions of the tooth roots and adjacent tissues. METHODS: Six minipigs were used. In each animal, 4 defects were created at the mesial aspects of the maxillary and mandibular first permanent molars; the defects on the right were filled with the xenograft (test side), and the opposite defects (control side) were filled with blood clots and allowed to heal spontaneously. Three months later, orthodontic appliances were placed in each quadrant to allow mesial bodily movement of the first permanent molars. When the teeth were moved about halfway into the defect spaces, the animals were killed, and the areas of interest were harvested. The mesial roots of the first molars and adjacent tissues were histologically and morphometrically evaluated. The volume density of bone tissue, the percentage of root resorption, and the bone height were evaluated with image analysis software. RESULTS: Data analysis showed that (1) the percentage of root resorption was smaller (P = .0359) for the test group (4.16%) compared with the control (6.52%); (2) there was no statistically significant differences between groups concerning the volume density of neoformed bone (P >.05); (3) the bovine bone matrix was almost totally replaced by structured bone tissue; (4) the test group had a statistically significant smaller bone height loss (2.18 mm, P = .0018) than the control group (3.26 mm). CONCLUSIONS: Based on these results, it was concluded that teeth can be moved into areas of bone defects previously filled with xenograft.