Navegando por Assunto "Mandíbula"

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Acesso aberto (Open Access)
Analysis of the mental foramen using cone beam computerized tomography
(Universidade Federal do Pará, 2015-08) SAITO, Kunihiro; ARAÚJO, Ney Soares de; SAITO, Miki Taketomi; PINHEIRO, João de Jesus Viana; CARVALHO, Pedro Luiz de
Introduction: Knowledge of the anatomical structures located in the region between the mental foramina is of critical importance in pre-operative planning. Objective: To evaluate the position of the mental foramen relative to the apices of the teeth and the distance to the edges of the mandible, using cone beam computerized tomography. Material and method: One hundred cone beam computerized tomographs of the mandible were evaluated; the tomographs were taken using a single tomographic device. Each image chosen was evaluated repeatedly from both sides of the mandible, the position of the mental foramen, indicating the region in which the foramen was found and the measures of the mental foramen, the lingual cortex and the mandibular base. Initially, the data were analyzed descriptively. A value of p<0.05 was chosen as the level of significance. Result: Forty-two percent of the mental foramina were located in the apex of the second pre-molar. The lingual margin of the mental foramen was located, on average, 3.1mm from the lingual cortex. The lower margin of the mental foramen was located 7.25 mm above the lower edge of the mandible. Conclusion: The mental foramen was located more frequently at a level of the apices of the second pre-molars, with a distance to the lingual cortex, on average, of 3.1mm and to the base of the mandible, on average, of 7.25 mm.
Acesso aberto (Open Access)
Changes in lower dental arch dimensions and tooth alignment in young adults without orthodontic treatment
(Universidade Federal do Pará, 2015-06) MAUAD, Bruno Aldo; SILVA, Robson Costa; ARAGÓN, Mônica Lídia Castro de; PONTES, Luana Farias; SILVA JÚNIOR, Newton Guerreiro da; NORMANDO, Antonio David Corrêa
Objective: The aim of this longitudinal study, comprising young adults without orthodontic treatment, was to assess spontaneous changes in lower dental arch alignment and dimensions. Methods: Twenty pairs of dental casts of the lower arch, obtained at different time intervals, were compared. Dental casts obtained at T1 (mean age = 20.25) and T2 (mean age = 31.2) were compared by means of paired t-test (p < 0.05). Results: There was significant reduction in arch dimensions: 0.43 mm for intercanine (p = 0.0089) and intermolar (p = 0.022) widths, and 1.28 mm for diagonal arch length (p < 0.001). There was a mild increase of approximately 1 mm in the irregularity index used to assess anterior alignment (p < 0.001). However, regression analysis showed that changes in the irregularity index revealed no statistically significant association with changes in the dental arch dimensions (p > 0.05). Furthermore, incisors irregularity at T2 could not be predicted due to the severity of this variable at T1 (p = 0.5051). Conclusion: Findings suggest that post-growth maturation of the lower dental arch leads to a reduction of dental arch dimensions as well as to a mild, yet significant, increase in dental crowding, even in individuals without orthodontic treatment. Furthermore, dental alignment in the third decade of life cannot be predicted based on the severity of dental crowding at the end of the second decade of life
Acesso aberto (Open Access)
Habilidade de ortodontistas e leigos na percepção de assimetrias da mandíbula
(2011-08) SILVA, Narjara Condurú Fernandes da; AQUINO, Éllida Renata Barroso de; MELLO, Karina Corrêa Flexa Ribeiro; MATTOS, José Nazareno Rufino de; NORMANDO, Antonio David Corrêa
OBJECTIVE: To analyze orthodontists’ and laypersons’ perceptions of facial asymmetries caused by mandibular changes. METHODS: The faces of two patients, a man and a woman, were photographed in natural head position, and additional photographs were produced with progressive mandibular shifts of 2, 4 and 6 mm from maximum habitual intercuspation (MHI). Intraclass correlation coefficients (ICC) and weighted kappa coefficients were used to test method reproducibility. The differences in scores for mandibular positions between orthodontists and lay persons were examined using Friedman analysis. All statistical analyses were performed at 95% confidence interval. RESULTS: Orthodontists only perceived shifts greater than 4 mm from MHI position (p<0.05), and laypersons had similar results when analyzing the woman’s photographs. However, when examining the man’s photographs, laypersons did not perceive any change in relation to MHI. (p>0.05). Although median scores assigned by orthodontists were, in general, lower than those of laypersons, this difference was only significant for the 6-mm shift in both patients. CONCLUSIONS: Orthodontists and laypersons evaluated mandibular asymmetries differently. Orthodontists tended to be more critical when asymmetries were more severe. The evaluation of facial asymmetries also varied according to what patient was being examined, particularly among lay examiners.