Percorrer por autor "Pereira, Pedro Mariano"
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- 3D assessment of mandibular buccal shelf geometry for optimal micro-implant placement site in Portuguese individuals : a retrospective cone-beam computed tomography studyPublication . Borga, Joana; Bugaighis, Iman; Proença, Luís; Pereira, François Durand; Costa, Helder Nunes; Pereira, Pedro MarianoObjectives: To determine the most favourable Micro-Implant (MI) insertion site along the mandibular buccal shelf (MBS), using Cone Beam Computed Tomography (CBCT). Methods: This retrospective study assessed CBCT scans from 90 Portuguese patients (32 males and 58 females, aged 14 to 40 years). Paired MBS sites were determined. Comparative and correlation analyses were performed at p < 0.05. Results: A significant increase in MBS width was observed from the mesial to the distal direction (p < 0.001). Conversely, both the MBS steepness and cortical bone thickness significantly decreased from mesial to distal (p < 0.001). Significant negative correlation was also found between age and cortical bone thickness adjacent to the distobuccal cusp and distal tangent of both mandibular second molars (r ≤ −0.373, p ≤ 0.007). Furthermore, significant asymmetric differences were identified between the right and left MBS steepness as well as in the paired cortical bone thickness at the mesiobuccal cusp, buccal groove, and distobuccal cusp of the mandibular second molar (p ≤ 0.016). Conclusions: The results indicate that although there are sufficient MBS width and cortical bone thickness, vestibular to the mandibular second molar for MI insertion, the sites towards the distal root of the mandibular second molar are more favourable when considering MBS steepness. These findings are consistent for both sexes and apply to young and old individuals.
- 3D assessment of the relationship of the mandibular buccal shelf with the mandibular canal : a CBCT retrospective studyPublication . Feliciano, Jéssica; Pereira, Pedro Mariano; Proença, Luís; Borga, Joana; Bugaighis, ImanObjective: This study aimed to evaluate the micro-implant safest insertion site on the mandibular buccal shelf (MBS) without compromising the integrity of the mandibular canal (MC). Methods: This retrospective investigation included cone-beam computed tomography (CBCT) of 96 Portuguese patients (58 females and 38 males, average age of 25.5±10.2 years). Measurements were taken in four bilateral MBS sites buccal to the mandibular second molar; tangent to the distal surface (7D), distobuccal cusp tip (7CD), buccal groove (7S) and mesiobuccal cusp tip (7CM). The transversal MBS midpoint was also determined, and the maximum angulation from the transversal MBS midpoint was extracted relative to the true vertical plane. Subsequently, the distance from the MBS midpoint to the MC was calculated at this angulation. Descriptive and inferential statistical analyses were performed at p<0.05 Results: Significant correlations were observed among several variables and age, sex and bilateral asymmetry (p<0.05). The MBS transversal width and the distance from the MBS midpoint to the MC progressively increased in the posterior direction while the angulation decreased. Conclusion: The most appropriate micro-implant insertion location compared to the other MBS investigated sites, in the absence of impacted third molars, is adjacent to the distal surface of the second molar. This finding is consistent across all age groups, sexes, and insertion sides. However, due to the demonstrated variability, taking a CBCT scan prior to mini-implant insertion might be considered to minimize the risk of injury to the inferior alveolar nerve.
- Associação da má oclusão de Classe II Divisão 2 com anomalias do desenvolvimento dentárioPublication . Pereira, Pedro Mariano; Ferreira, Afonso Pinhão; Tavares, Purificação; Braga, Ana Cristina
- Avaliação da perceção estética da posição labial sagital em diferentes painéis de observadoresPublication . Viegas, Marta; Pereira, Pedro Mariano
- Avaliação da perceção estética do perfil facial em diferentes painéis de observadoresPublication . Viegas, Marta M.; Pereira, Pedro Mariano; Proença, LuísObjetivo: Avaliar se a perceção estética da convexidade do perfil facial é semelhante entre os diferentes painéis de avaliadores. Métodos: Foram utilizadas silhuetas de perfil construídas no programa Adobe Photoshop Cs5®. A partir de um perfil de referência com 12° de convexidade facial foram criadas 4 silhuetas com convexidade de 0°, 6°, 18° e 24°. Foram avaliadas por especialistas em ortodontia, estudantes de medicina dentária e por um grupo de controlo que representa a população em geral, mediante um questionário online. Resultados: Verificaram‐se diferenças estatisticamente significativas entre grupos quanto à perceção estética da convexidade do perfil facial. Os especialistas em ortodontia e os estudantes de medicina dentária consideram mais estético o perfil de convexidade 12°. A população em geral prefere o perfil de 18°. Conclusões: A perceção estética da convexidade do perfil facial não é idêntica para os especialistas em ortodontia, estudantes de medicina dentária e para o grupo de controlo que representa a população geral.
- Avaliação de perceção estética do perfil facial em diferentes painéis de observadoresPublication . Viegas, Marta; Pereira, Pedro Mariano
- Bone availability in the sagittal dimension of the infrazygomatic crest for miniscrew insertion : a retrospective cone-beam computed tomography studyPublication . Furão, Susana; Bugaighis, Iman; Proença, Luís; Brito, José; Costa, Hélder Nunes; Pereira, François Durand; Pereira, Pedro MarianoBackground: There is limited information available regarding the bone volume in the sagittal dimension of the infrazygomatic crest (IZC) that is safe for the insertion of a temporary skeletal anchorage device. The objective of this study was to assess the sagittal bone availability when the anterior and posterior walls of the IZC reach an inclination of 45°. Methods: A cross-sectional investigation was undertaken on 100 cone-beam computed tomography scans of 40 males and 60 females. A total of 20 landmarks were digitized for each IZC outline, 1 mm from the vestibular alveolar bone, and their x, y, and z coordinates were extracted. Afterward, the sagittal measurement of the IZC at which the curvature reached 45° was recorded. Symmetry of measurements was assessed using paired-samples t tests. In addition, these measurements were compared as a function of sex and age group (≤21 vs >21 years) using an independent-samples t test and the Spearman rank correlation coefficient test (P <0.05). Results: There were no significant differences between paired sagittal measurements of the IZC (3.5 ± 1.5 mm on the right side and 3.6 ± 1.3 mm on the left side; P = 0.144), except for younger patients (P = 0.030). In addition, no significant differences were found between corresponding male and female measurements (P ≥0.149). A significant discrepancy was identified between the younger age group (3.2 ± 1.2 mm) and the older cohort (3.8 ± 1.6 mm) for the sagittal dimension of the right IZC (P = 0.038), with an estimated mean difference of 0.03-1.16 mm (95% confidence interval). A significant positive weak correlation was found between the sagittal dimension of the right IZC and age (ρ = 0.201; P = 0.045). Conclusions: Sufficient IZC bone volume is available at an angle of 45° for inserting a temporary skeletal anchorage device, with no sex or side variation, except for the significantly greater sagittal dimension of the right IZC in older patients.
- Comparison of shear bond strength of metallic brackets bonded to ceramic surfaces utilizing different adhesive systems : an in vitro studyPublication . Pulido, María Belén Paz; Pereira, Pedro Mariano; Pitschielller, Ricardo; Proença, Luís; Bugaighis, ImanOBJECTIVE: To compare the shear bond strength (SBS) of orthodontic brackets bonded to three different types of ceramic surfaces (feldspathic, lithium disilicate, and zirconium) using Assure® Plus All and Transbond™ XT adhesives. MATERIALS AND METHODS: The sample comprised 72 monolithic computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic samples that were randomly divided into six groups of 12 specimens each. Three groups (G1, feldspathic ceramic; G3, lithium disilicate ceramic; G5, zirconium surfaces) were bonded to metal brackets using Assure® Plus All adhesive, whereas the remaining three groups (G2, G4, G6; with the ceramic type in the same order as that in the previous groups) were bonded to metal brackets using Transbond™ XT. The samples were then subjected to 10,000 thermocycles. The SBS was calculated using the shear tests. The site of bonding failure was classified using the adhesive remnant index (ARI) score. One-way analysis of variance (ANOVA) and Kruskal–Wallis tests were used for statistical analyses at a 5% significance level. RESULTS: Statistically significant differences were observed in the mean SBS values of the groups (P < 0.001). The mean SBS for G6 (zirconium plus Transbond™ XT) (2.52 MPa) was significantly lower than that for all other groups. Furthermore, statistically significant differences were found in the ARI score distribution among the groups (P < 0.001). Differences were identified between G6 and G3 (lithium disilicate Plus All Assure® Plus All) and G5 (zirconium plus Assure® Plus All). CONCLUSIONS: The mean bonding strength of brackets with Assure® Plus All was higher than that with Transbond™ XT for all three types of ceramics. However, all groups, except the zirconium plus Transbond™ XT group, showed acceptable bonding strength for orthodontic purposes. The application of hydrofluoric acid followed by silane and finally the Assure® Plus All adhesive system is adequate for bonding brackets to any of the ceramic tested surfaces.
- Criteria for early diagnosis of third molar agenesis : a retrospective radiographic studyPublication . Dumas, Margaux; Pereira, Pedro Mariano; Bugaighis, Iman; Retto, Paulo Fernandes; Proença, LuísObjective: To explore the association between chronological, dental and skeletal ages and early diagnosis of third molars agenesis. Material and methods: This retrospective radiographic study comprised a sample of 282 Portuguese patients (122 males and 160 females) who sought orthodontic treatment between 2007 and 2018. Each participant had panoramic and lateral cephalometric radiographs performed before and after the age of 14 years. The chronological age was categorized into three intervals between 11.0 and 13.11 years of age. The full eruption of the four-second molars was used as a criterion in determining dental age. Skeletal age was verified by the vertebral maturation method. The diagnosis of agenesis of third molars was initially performed by observation of the initial panoramic radiography undertaken before the age of 14 years. Subsequently, the diagnosis of agenesis of third molars was confirmed by visualizing the second panoramic radiography, obtained after the age of 14 years. The association between the accuracy of the diagnosis and the chronological, dental and skeletal ages was evaluated using the chi-square test, at a 5% significance level. Results: No significant association between chronological age and alterations in the diagnosis of third molar agenesis was identified. However, there was a significant association between third molar agenesis and both dental age (p<0.001) and skeletal age (p=0.006). Conclusion: The eruption of the four-second molars and the peak of growth could be considered as criteria for early diagnosis of third molar agenesis, whereas chronological age is not a reliable diagnostic indicator.