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1.
J Appl Oral Sci ; 28: e20190364, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32348442

RESUMEN

Objective Maxillary molar distalization with intraoral distalizer appliances is a non-extraction orthodontic treatment used to correct molar relationship in patients with Class II malocclusion presenting maxillary dentoalveolar protrusion and minor skeletal discrepancies. This study compares the changes caused by three distalizers with different force systems. Methodology 71 patients, divided into three groups, were included. The Jones jig group (JJG, n=30; 16 male, 14 female, 13.17 years mean age) was treated with the Jones jig for 0.8 years. The Distal jet group (DJG, n=25; 8 male, 17 female, 12.57 years mean age) was treated with the Distal jet for 1.06 years. The First Class group (FCG, n=16; 6 male, 10 female, 12.84 years mean age) was treated with the First Class for 0.69 years. Intergroup treatment changes were compared using one-way ANOVA, followed by post-hoc Tukey's tests. Results Intergroup comparisons showed significantly greater maxillary incisor protrusion in DJG than in FCG (2.56±2.24 mm vs. 0.74±1.39mm, p=0.015). The maxillary first premolars showed progressive and significantly smaller mesial angulation in JJG, FCG and DJG, respectively (14.65±6.31º, 8.43±3.99º, 0.97±3.16º; p<0.001). They also showed greater mesialization in JJG than FCG (3.76±1.46 mm vs. 2.27±1.47 mm, p=0.010), and greater extrusion in DJG compared to JJG (0.90±0.77 mm vs 0.11±0.60 mm, p=0.004). The maxillary second premolars showed progressive and significantly smaller mesial angulation and mesialization in JJG, FCG and DJG, respectively (12.77±5.78º, 3.20±3.94º, -2.12±3.71º and 3.87±1.34 mm, 2.25±1.40 mm, 1.24±1.26 mm, respectively; p<0.001). DJG showed smaller distal angulation of maxillary first molars (-2.14±5.09º vs. -7.73±4.28º and -6.05±3.76º, for the JJG and FCG, respectively; p<0.001) and greater maxillary second molars extrusion (1.17±1.41 mm vs -0.02±1.16 mm and 0.16±1.40 mm, for the JJG and FCG, respectively; p=0.003). Overjet change was significantly larger in DJG compared to FCG (1.79±1.67 mm vs 0.68±0.84; p=0.046). Treatment time was smaller in FCG (0.69±0.22 years vs 0.81±0.33 years and 1.06±0.42 years, comparing it with the JJG and DJG, respectively; p=0.005). Conclusion The three appliances corrected the Class II molar relationship by dentoalveolar changes. The Distal jet produced smaller molar distal angulation than the Jones jig and First Class. The First Class appliance showed less anchorage loss, greater percentage of distalization and shorter treatment time than the Jones jig and Distal jet.


Asunto(s)
Maloclusión de Angle Clase II/terapia , Diente Molar/fisiopatología , Diseño de Aparato Ortodóncico , Aparatos Ortodóncicos Fijos , Técnicas de Movimiento Dental/instrumentación , Adolescente , Análisis de Varianza , Cefalometría , Niño , Femenino , Humanos , Masculino , Maloclusión de Angle Clase II/fisiopatología , Métodos de Anclaje en Ortodoncia/instrumentación , Valores de Referencia , Reproducibilidad de los Resultados , Estudios Retrospectivos , Resultado del Tratamiento
2.
J. appl. oral sci ; 28: e20190364, 2020. tab, graf
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1101252

RESUMEN

Abstract Objective Maxillary molar distalization with intraoral distalizer appliances is a non-extraction orthodontic treatment used to correct molar relationship in patients with Class II malocclusion presenting maxillary dentoalveolar protrusion and minor skeletal discrepancies. This study compares the changes caused by three distalizers with different force systems. Methodology 71 patients, divided into three groups, were included. The Jones jig group (JJG, n=30; 16 male, 14 female, 13.17 years mean age) was treated with the Jones jig for 0.8 years. The Distal jet group (DJG, n=25; 8 male, 17 female, 12.57 years mean age) was treated with the Distal jet for 1.06 years. The First Class group (FCG, n=16; 6 male, 10 female, 12.84 years mean age) was treated with the First Class for 0.69 years. Intergroup treatment changes were compared using one-way ANOVA, followed by post-hoc Tukey's tests. Results Intergroup comparisons showed significantly greater maxillary incisor protrusion in DJG than in FCG (2.56±2.24 mm vs. 0.74±1.39mm, p=0.015). The maxillary first premolars showed progressive and significantly smaller mesial angulation in JJG, FCG and DJG, respectively (14.65±6.31º, 8.43±3.99º, 0.97±3.16º; p<0.001). They also showed greater mesialization in JJG than FCG (3.76±1.46 mm vs. 2.27±1.47 mm, p=0.010), and greater extrusion in DJG compared to JJG (0.90±0.77 mm vs 0.11±0.60 mm, p=0.004). The maxillary second premolars showed progressive and significantly smaller mesial angulation and mesialization in JJG, FCG and DJG, respectively (12.77±5.78º, 3.20±3.94º, -2.12±3.71º and 3.87±1.34 mm, 2.25±1.40 mm, 1.24±1.26 mm, respectively; p<0.001). DJG showed smaller distal angulation of maxillary first molars (-2.14±5.09º vs. -7.73±4.28º and -6.05±3.76º, for the JJG and FCG, respectively; p<0.001) and greater maxillary second molars extrusion (1.17±1.41 mm vs -0.02±1.16 mm and 0.16±1.40 mm, for the JJG and FCG, respectively; p=0.003). Overjet change was significantly larger in DJG compared to FCG (1.79±1.67 mm vs 0.68±0.84; p=0.046). Treatment time was smaller in FCG (0.69±0.22 years vs 0.81±0.33 years and 1.06±0.42 years, comparing it with the JJG and DJG, respectively; p=0.005). Conclusion The three appliances corrected the Class II molar relationship by dentoalveolar changes. The Distal jet produced smaller molar distal angulation than the Jones jig and First Class. The First Class appliance showed less anchorage loss, greater percentage of distalization and shorter treatment time than the Jones jig and Distal jet.


Asunto(s)
Humanos , Masculino , Femenino , Niño , Adolescente , Técnicas de Movimiento Dental/instrumentación , Diseño de Aparato Ortodóncico , Aparatos Ortodóncicos Fijos , Maloclusión de Angle Clase II/terapia , Diente Molar/fisiopatología , Valores de Referencia , Cefalometría , Reproducibilidad de los Resultados , Estudios Retrospectivos , Análisis de Varianza , Resultado del Tratamiento , Métodos de Anclaje en Ortodoncia/instrumentación , Maloclusión de Angle Clase II/fisiopatología
3.
Am J Orthod Dentofacial Orthop ; 156(4): 493-501, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31582121

RESUMEN

INTRODUCTION: The purpose of this research was to evaluate dental compensation in facial asymmetry and its correlation with skeletal variables using cone-beam computed tomography. METHODS: Sixty adult patients were retrospectively divided into asymmetry (mean age, 21.8 ± 5.4 years) and symmetry groups (mean age, 28.1 ± 4.1 years); both groups comprised 30 patients. Independent and paired t tests were used for comparisons between the asymmetry and symmetry groups and between deviated (Dv) and nondeviated (NDv) sides of the asymmetry group, respectively. Pearson correlation between dental and skeletal variables was performed. RESULTS: The mean value of menton deviation was 9.4 mm in the asymmetry group. Compared with the symmetry group, the direction and amount of dental compensation of the asymmetry group were as follows: 2.5-mm extrusion of the maxillary first molar (UM6) at NDv (P <0.05); 1.8-mm higher position of the mandibular canine (LC) from the mandibular horizontal plane using mental foramen (MHP_mf) at NDv (P <0.05); 6°-more buccoversion of UM6 at Dv; 3.7°-more linguoversion of UM6 at NDv; 4.8°-more buccoversion of the maxillary canine (UC) at Dv; 4.9°-more buccoversion of the mandibular molar (LM6) at NDv; and 2.6°-more linguoversion of LC at Dv. Dental compensation correlated or marginally correlated with skeletal variables of the deviated mandible. CONCLUSIONS: Dental compensations, extrusion of the maxillary molars on the NDv, and buccal tipping of the maxillary teeth and lingual tipping of the mandibular teeth on the Dv, were observed. The mandibular body length was associated with linguoversion of the mandibular molars on the Dv. The ramal inclination was related to the extrusion of the maxillary molars on the NDv.


Asunto(s)
Cefalometría/métodos , Tomografía Computarizada de Haz Cónico/métodos , Asimetría Facial/diagnóstico por imagen , Maloclusión/diagnóstico por imagen , Diente Molar/diagnóstico por imagen , Adolescente , Adulto , Estética Dental , Asimetría Facial/fisiopatología , Femenino , Humanos , Imagenología Tridimensional/métodos , Masculino , Maloclusión/fisiopatología , Persona de Mediana Edad , Diente Molar/fisiopatología , Estudios Retrospectivos
4.
Am J Orthod Dentofacial Orthop ; 156(2): 178-185, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31375227

RESUMEN

INTRODUCTION: This study aimed to identify significant factors affecting the spontaneous angular changes of impacted mandibular third molars as a result of second molar protraction. Temporary skeletal anchorage devices in the missing mandibular first molar (ML-6) or missing deciduous mandibular second molar (ML-E) with missing succedaneous premolar spaces provided traction. METHODS: Forty-one mandibular third molars of 34 patients (10 male and 24 female; mean age 18.3 ± 3.7 years) that erupted after second molar protraction were included in this study. They were classified into upright (U) and tilted (T) groups. Linear and angular measurements were performed at the time of treatment initiation (T1) and of ML-6 or ML-E space closure (T2). Regression analyses were used to identify significant factors related to third molar uprighting. RESULTS: Nolla stage (odds ratio [OR] 4.1), sex (OR 0.003 for male), third molar angulation at T1 (OR 1.1), missing tooth space (OR 0.006), rate of third molar eruption (OR 23.3), and rate of second molar protraction (OR 0.2) significantly affected third molar uprighting. Age, third molar angulation at T1, rate of third molar eruption, and rate of second molar protraction were significant factors for predicting third molar angulation at T2. CONCLUSIONS: Available space for third molar eruption before and after second molar protraction is not associated with uprighting of erupting third molars. Older patients whose third molars are in greater Nolla stage, are in a more upright position at T1, and have a greater eruption rate have a greater chance for third molar uprighting. Alternatively, an increase in second molar protraction rate results in mesial tipping of the third molars.


Asunto(s)
Maloclusión/prevención & control , Maloclusión/fisiopatología , Mandíbula/fisiopatología , Tercer Molar/fisiopatología , Diente Impactado/fisiopatología , Adolescente , Adulto , Puntos Anatómicos de Referencia , Diente Premolar , Femenino , Humanos , Masculino , Maloclusión/diagnóstico por imagen , Mandíbula/anatomía & histología , Mandíbula/diagnóstico por imagen , Diente Molar/anatomía & histología , Diente Molar/diagnóstico por imagen , Diente Molar/fisiopatología , Tercer Molar/anatomía & histología , Tercer Molar/diagnóstico por imagen , Aparatos Ortodóncicos , Cierre del Espacio Ortodóncico , Ortodoncia Correctiva , Erupción Dental , Diente Primario , Diente Impactado/complicaciones , Diente Impactado/diagnóstico por imagen , Adulto Joven
5.
Methods Mol Biol ; 1922: 111-119, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30838569

RESUMEN

Different animal models have been introduced recently to study the process of reparative dentinogenesis in response to injury-induced pulp exposure. Using a mouse model is advantageous over other animal models since mice can be genetically manipulated to examine specific cellular pathways and lineage trace the progeny of a single cell. However, enabling a standardized molar damage in mice is demanding due to the small size of the teeth compared to the available dental instruments. Here we describe a reproducible and reliable in vivo model that allows us to study dentinogenesis in the first maxillary mouse molar.


Asunto(s)
Dentinogénesis , Modelos Animales , Endodoncia Regenerativa/métodos , Traumatismos de los Dientes/terapia , Animales , Ratones , Diente Molar/lesiones , Diente Molar/fisiopatología , Traumatismos de los Dientes/fisiopatología
6.
Biomed Res Int ; 2018: 9352130, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30519592

RESUMEN

Aim: To evaluate, with three-dimensional analysis, the effectiveness of alveolar ridge preservation (ARP) after maxillary molar extraction in reducing alveolar bone resorption and maxillary sinus pneumatization when compared to unassisted socket healing. Methods: Patients were included in the study following inclusion criteria and underwent minimally traumatic maxillary molar extraction followed by ARP using synthetic nanohydroxyapatite (Fisiograft Bone, Ghimas, Italy) (test group) or unassisted socket healing (control group). Cone-beam computerized tomographies (CBCT) were performed immediately after tooth extraction (T0) and 6 months postoperatively (T1). CBCTs were superimposed by using a specific software (Amira, Thermo Fisher Scientific, USA) and the following items were analyzed in both groups: (i) postextractive maxillary sinus floor expansion in coronal direction and (ii) postextractive alveolar bone dimensional changes (both vertical and horizontal). All data were tested for normality and equality of variance and subsequently analyzed by independent samples T-test and Mann-Whitney test. Results: Thirty patients were treated by three centers and twenty-six (test n=13; control n=13) were included in the final analysis. Mean sinus pneumatization at T1 was 0.69±0.48 mm in the test group and 1.04±0.67 mm in the control group (p=0.15). Mean vertical reduction of the alveolar bone at T1 was 1.62±0.49 mm in the test group and 2.01±0.84 mm in the control group (p=0.08). Mean horizontal resorption of crestal bone at T1 was 2.73±1.68 mm in test group and 3.63±2.24 mm in control group (p=0.24). Conclusions: It could be suggested that ARP performed after maxillary molar extraction may reduce the entity of sinus pneumatization and alveolar bone resorption, compared to unassisted socket healing. This technique could decrease the necessity of advanced regenerative procedures prior to dental implant placement in posterior maxilla.


Asunto(s)
Pérdida de Hueso Alveolar/fisiopatología , Aumento de la Cresta Alveolar , Resorción Ósea/prevención & control , Extracción Dental/efectos adversos , Adulto , Pérdida de Hueso Alveolar/diagnóstico por imagen , Pérdida de Hueso Alveolar/prevención & control , Proceso Alveolar/diagnóstico por imagen , Proceso Alveolar/crecimiento & desarrollo , Proceso Alveolar/fisiopatología , Proceso Alveolar/cirugía , Resorción Ósea/diagnóstico por imagen , Resorción Ósea/fisiopatología , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Masculino , Maxilar/diagnóstico por imagen , Maxilar/crecimiento & desarrollo , Maxilar/fisiopatología , Maxilar/cirugía , Seno Maxilar/crecimiento & desarrollo , Seno Maxilar/fisiopatología , Seno Maxilar/cirugía , Persona de Mediana Edad , Diente Molar/diagnóstico por imagen , Diente Molar/fisiopatología , Diente Molar/cirugía
8.
Curr Med Sci ; 38(5): 914-919, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30341529

RESUMEN

This study aims to evaluate the long-term stability of vertical control in hyperdivergent patients treated with temporary anchorage devices. The sample included 20 hyperdivergent patients without anterior open bite. The temporary anchorage devices were used to intrude the upper incisor and molars for vertical control. Lateral cephalograms were established prior to treatment, immediately after treatment, and during retention. The upper molars and incisors were intruded by 1.33 mm and 1.41 mm after treatment (P<0.05). U6-PP increased by 0.11 mm and 0.23 mm during the first and second stages of retention (P>0.05). U1-PP was found to possess a significant extrusion of 1.2 mm during the first stage (P<0.05), which increased by 0.68 mm during the second stage (P>0.05). The mandibular plane angle (MP-SN) decreased by 2.58 degrees following treatment, and underwent a relapse of 0.51 degree and 0.42 degree during the first and second stages of retention respectively (P>0.05). No significant soft tissue changes occurred, with the exception of increased upper lip length during the second stage (P<0.05). Maxillary anterior and posterior intrusions, counter clockwise rotation of the mandibular plane, and improved profiles can be successfully achieved following treatment with vertical control. During the first stage of retention (less than three years), intruded molars and incisors both exhibited some extrusion, and molars had better long-term stability than incisors. During the second stage of retention (three to six years), the therapeutic effects appeared stable, with the exception of some increase in upper lip length. Rotated mandibular plane remained stable during the entire retention period.


Asunto(s)
Retención de Dentadura/métodos , Mordida Abierta/terapia , Métodos de Anclaje en Ortodoncia/métodos , Cefalometría , Femenino , Humanos , Incisivo/fisiopatología , Masculino , Mandíbula/diagnóstico por imagen , Mandíbula/fisiopatología , Maxilar/diagnóstico por imagen , Maxilar/fisiopatología , Persona de Mediana Edad , Diente Molar/fisiopatología , Mordida Abierta/diagnóstico por imagen , Mordida Abierta/fisiopatología , Diseño de Aparato Ortodóncico/métodos , Técnicas de Movimiento Dental/métodos
9.
J Musculoskelet Neuronal Interact ; 18(3): 366-374, 2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-30179214

RESUMEN

OBJECTIVE: The purpose of this experimental study was to investigate in depth the effects of osteopenia related to the rate, as well as to the quality of orthodontic tooth movement, by combining experimental ovariectomy and molar movement in rats. METHODS: Twenty-four six-month-old female Wistar rats were used in this study. The animals were divided into two groups consisting of twelve animals each: Group A (control group) was subjected to orthodontic movement of the upper right first molars. Group B was subjected to orthodontic movement of the upper right first molar following bilateral ovariectomy. Ovariectomy was performed on the first experimental day and the upper right first molars were subjected to orthodontic forces 60 days post-ovariectomy, lasting for 14 days. RESULTS AND CONCLUSION: Direct inspections of the upper jaws, measurements of orthodontic movement of the upper right first molars of Group A and B, as well as histologic examinations of the alveolar bone in the upper right and left first molar regions, showed that osteopenia affects the rate of orthodontic tooth movement, as well as the quality of alveolar bone remodeling, in ovariectomized rats. Specifically, in the ovariectomized animals the alveolar bone of the non-loaded side showed extensive internal resorption, with large marrow cavities, whereas the alveolar bone of the loaded side was dense with almost no marrow cavity and frontal resorption on the surface. It appears that alveolar remodeling after the exertion of orthodontic forces follows the general paradigm of osteoporotic bone remodeling after loading.


Asunto(s)
Enfermedades Óseas Metabólicas/fisiopatología , Diente Molar/fisiopatología , Técnicas de Movimiento Dental , Animales , Ovariectomía , Ratas , Ratas Wistar
10.
J Mech Behav Biomed Mater ; 80: 77-80, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29414478

RESUMEN

Results are presented for wear tests on human molar enamel in silica particle mediums. Data for different particle concentrations show severe wear indicative of material removal by plasticity-induced microcrack formation, in accordance with earlier studies. The wear rates are independent of low vol% particles, consistent with theoretical models in which occlusal loads are distributed evenly over all interfacial microcontacts. However, perhaps counter-intuitively, the wear rate diminishes substantially at higher vol%. This is attributed to a greater proportion of lower-load microcontacts transitioning into a region of mild wear, where microcracking is suppressed. Implications of these results in relation to evolutionary biology and dentistry are explored.


Asunto(s)
Esmalte Dental/química , Diente Molar/fisiopatología , Estrés Mecánico , Desgaste de los Dientes/fisiopatología , Humanos , Propiedades de Superficie
11.
Acta Odontol Latinoam ; 31(3): 131-137, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30829367

RESUMEN

The aim of this study was to evaluate the morphological alterations of epithelial cell rests of Malassez (ERMs) and their relationship with root resorption, in an experimental periodontitis (EP) model at 4 and 11 days. EP was induced in 14 male Wistar rats by placing a cotton thread ligature around the neck of the first lower right molar, for 4 (n=7) and 11 (n=7) days. The contralateral molar (left) was used as control. Following euthanasia, jaws were extracted and processed histologically to provide mesio-distal sections which were subject to H&E stain and histochemical detection technique with tartrate-resistant acid phosphatase (TRAP). The following histomorphometricparameters were evaluated on micrographs: bone area (BAr./TAr)(%), number of ERMs/mm2, number of cells/ERM, ERMs area (µm2), and percentage of root resorption surfaces (%RR). The results were analyzed statistically by ANOVA and Bonferronipost hoc (p≤ 0.05). Significant bone loss was observed in molars with EP compared to their controls. In the EP 4-Day group, no change was observed in the parameters with relation to the ERMs; however, in the EP 11-Day group, there was significant root resorption (%RR) (C: 3.21±3.07, EP-4D: 3.91±3.17, EP-11D: 23.67± 11.40; p≤ 0,05) and increase in ERMs area (µm2) (C: 455.87±145.42, EP-4D: 577.6±156.1, EP-11D: 1046.3± 582.9; p≤ 0,05). No TRAP+ ERM was found in either group. ERM hypertrophy may be related to ERMpartici-pation in mechanisms tending to establish periodontal homeostasis, inhibiting resorption and contributing toperiodon-tal regeneration.


Asunto(s)
Células Epiteliales/citología , Diente Molar/fisiopatología , Periodontitis/fisiopatología , Resorción Radicular , Animales , Modelos Animales de Enfermedad , Células Epiteliales/fisiología , Células Epiteliales/ultraestructura , Masculino , Diente Molar/citología , Ratas , Ratas Wistar
12.
Dental Press J Orthod ; 23(6): 56-63, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30672986

RESUMEN

OBJECTIVE: The objective of this study was to assess the external apical root resorption (EARR) of the maxillary posterior teeth after intrusion with miniscrews. METHODS: Fifteen patients (13 females and 2 males) with age ranging from 14.5 to 22 years (mean 18.1 ±2.03 years) were selected to participate in this study. All patients presented with anterior open bite of 3 mm or more. An intrusion force of 300 g was applied on each side to intrude the maxillary posterior teeth. Cone beam computed tomography (CBCT) scans were taken pretreatment and post-intrusion and were analyzed to evaluate the EARR. RESULTS: The maxillary posterior teeth were intruded in average 2.79 ± 0.46 mm (p< 0.001) in 5.1 ± 1.3 months, and all examined roots showed statistically significant EARR (p< 0.05) with an average of 0.55 mm, except the distobuccal root of the left first permanent molars and both the palatal and buccal roots of left first premolars, which showed no statistically significant changes. CONCLUSIONS: The evaluated teeth presented statistically significant EARR, but clinically, due to the small magnitude, it was not considered significant. Moreover, the CBCT provided a good visualization of all roots in all three planes, and it was effective in detecting minimal degrees of EARR.


Asunto(s)
Tornillos Óseos/efectos adversos , Imagenología Tridimensional/métodos , Maxilar/diagnóstico por imagen , Maxilar/patología , Mordida Abierta/terapia , Resorción Radicular/diagnóstico por imagen , Resorción Radicular/patología , Técnicas de Movimiento Dental/efectos adversos , Adolescente , Adulto , Diente Premolar , Tomografía Computarizada de Haz Cónico/métodos , Análisis del Estrés Dental , Femenino , Humanos , Masculino , Diente Molar/fisiopatología , Mordida Abierta/diagnóstico por imagen , Métodos de Anclaje en Ortodoncia/efectos adversos , Métodos de Anclaje en Ortodoncia/instrumentación , Métodos de Anclaje en Ortodoncia/métodos , Técnicas de Movimiento Dental/instrumentación , Técnicas de Movimiento Dental/métodos , Resorción Dentaria/diagnóstico por imagen , Resorción Dentaria/patología , Raíz del Diente/diagnóstico por imagen , Raíz del Diente/patología , Adulto Joven
13.
Biomed Res Int ; 2017: 1560175, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29109954

RESUMEN

Objective: The present study aimed to investigate the role of periapical diseases in inducing medication-related osteonecrosis of the jaws (MRONJ) using an ovariectomized (OVX) mice model. Materials and Methods: Twenty C57BL/6N female mice were randomly assigned to two groups. All mice were subjected to bilateral ovariectomy and then treated with oncologic dose of zoledronic acid (ZA) or vehicle for twelve weeks. Eight weeks after commence of drug administration, a pulpal exposure (PE) operation was performed on the first right lower molar to induce periapical periodontitis; the contralateral non-PE tooth was used as control. All animals were sacrificed four weeks after pulpal exposure, and the mandibles were harvested for radiological and histomorphometrical analysis. Results: Micro computed tomography (µ-CT) examination demonstrated that periapical diseases significantly increased alveolar bone resorption, and the resorption was greatly attenuated by ZA treatment. Concurrent ZA therapy significantly increased bone density and histological osteocyte necrosis in the presence of periapical lesions. Conclusion: ZA treatment reduced bone absorption resulting from periapical disease but increased the risk of developing MRONJ in the ovariectomized mouse model.


Asunto(s)
Difosfonatos/administración & dosificación , Imidazoles/administración & dosificación , Necrosis/fisiopatología , Osteonecrosis/tratamiento farmacológico , Enfermedades Periapicales/tratamiento farmacológico , Pérdida de Hueso Alveolar/tratamiento farmacológico , Pérdida de Hueso Alveolar/fisiopatología , Animales , Densidad Ósea/efectos de los fármacos , Conservadores de la Densidad Ósea/administración & dosificación , Modelos Animales de Enfermedad , Humanos , Maxilares/efectos de los fármacos , Maxilares/fisiopatología , Mandíbula/efectos de los fármacos , Mandíbula/fisiopatología , Ratones , Diente Molar/efectos de los fármacos , Diente Molar/fisiopatología , Diente Molar/cirugía , Osteocitos/efectos de los fármacos , Osteonecrosis/inducido químicamente , Osteonecrosis/fisiopatología , Enfermedades Periapicales/fisiopatología , Tomografía Computarizada por Rayos X , Ácido Zoledrónico
14.
Oper Dent ; 42(6): 646-657, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28976843

RESUMEN

OBJECTIVES: To evaluate the effects of direct composite resin without a post or with one or two fiberglass posts on the restoration of severely compromised endodontically treated molars. METHODS AND MATERIALS: Forty-five molars with 2 mm of "remaining tooth structure" were divided into three groups: Wfgp, restored with Filtek Z350XT without a fiberglass post; 1fgp, restored with Z350XT with one fiberglass post in the distal root canal; and 2fgp, restored with Z350XT with two fiberglass posts, one in the distal root canal and the other in the mesial-buccal root canal. The teeth were load cycled. Tooth remaining strain was measured using strain gauges (n=10) at two moments: TrSt-100 N, during 100 N occlusal loading, and TrSt-Fr, at fracture load. Fracture resistance was calculated, and fracture mode was classified. The elastic modulus and Vickers hardness were calculated using dynamic indentation (n=5). Stress distribution was analyzed by three-dimensional finite element analysis. RESULTS: The use of two fiberglass posts resulted in lower fracture resistance than was noted in the groups with one fiberglass post and without fiberglass posts. The lingual surface of the remaining tooth had higher strain values than the buccal surface, regardless of the restorative technique and moment of evaluation. The absence of a fiberglass post resulted in significantly higher strain values and more irreparable fracture modes than were noted in the other groups. The use of one fiberglass post had a better strain/fracture resistance ratio. Stresses were concentrated in the occlusal portion of the post and in the furcation region. The presence of one fiberglass post resulted in better stress distribution in the entire distal root dentin, reducing stress on the critical areas. CONCLUSIONS: The use of one fiberglass post for restoring molars with direct composite resin resulted in higher fracture resistance than did the use of two fiberglass posts; it also resulted in better tooth remaining strain and stress distribution and more reparable fracture modes than were seen in the group without a fiberglass post.


Asunto(s)
Resinas Compuestas/uso terapéutico , Restauración Dental Permanente/métodos , Diente Molar/fisiopatología , Técnica de Perno Muñón , Diente no Vital/fisiopatología , Fracaso de la Restauración Dental , Restauración Dental Permanente/efectos adversos , Análisis del Estrés Dental , Humanos , Técnicas In Vitro , Técnica de Perno Muñón/efectos adversos , Fracturas de los Dientes/etiología , Fracturas de los Dientes/prevención & control
15.
J Orofac Orthop ; 78(6): 487-493, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28913603

RESUMEN

PURPOSE: Bite force has been studied as representative of functional indices of mastication and its value may have diagnostic significance in disorders of the musculoskeletal system of facial bones. This study aimed to evaluate bite force in adolescents with and without orthodontic needs considering presence of temporomandibular disorders (TMD) as well as anthropometry: craniofacial dimensions and body mass index (BMI). METHODS: A total of 80 subjects were screened (61 females, 19 males; 18 ± 3 years old). Unilateral molar bite force was measured using a digital dynamometer with a fork thickness of 12 mm. Direct anthropometry was used to quantify craniofacial measurements. Dental Health Component of the Index of Orthodontic Treatment Need (IOTN-DHC) and the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were used to classify samples according to malocclusion and to TMD, respectively. Data were analyzed using normality tests, Mann-Whitney U test, and multiple linear regression analyses with stepwise backward elimination, controlling for the presence of malocclusion and TMD (p ≤ 0.05). RESULTS: The cephalic index was greater in females with malocclusion and the longitudinal cranial diameter was reduced in females with malocclusion. BMI was not different between normal and malocclusion groups for either gender. Bite force was negatively related with vertical dimension of the face, and positively related with facial width and facial index. The model explained 32% of bite force variability, considering the sample size (coefficient of determination R 2 = 0.324). CONCLUSIONS: Even when orthodontic needs and TMD signs and symptoms are present, stronger bite force is still observed in males and in subjects with smaller anterior facial heights and wider facial widths.


Asunto(s)
Antropometría , Fuerza de la Mordida , Cefalometría , Trastornos de la Articulación Temporomandibular/diagnóstico , Adolescente , Femenino , Humanos , Masculino , Diente Molar/fisiopatología , Evaluación de Necesidades , Ortodoncia Correctiva , Valores de Referencia , Trastornos de la Articulación Temporomandibular/fisiopatología , Adulto Joven
16.
Acta Odontol Scand ; 75(6): 394-401, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28502196

RESUMEN

OBJECTIVE: The main purpose of the present systematic review was to evaluate the quantitative effects of the pendulum appliance and modified pendulum appliances for maxillary molar distalization in Class II malocclusion. MATERIALS AND METHODS: Our systematic search included MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus and key journals and review articles; the date of the last search was 30 January 2017. We graded the methodological quality of the studies by means of the Quality Assessment Tool for Quantitative Studies, developed for the Effective Public Health Practice Project (EPHPP). RESULTS: In total, 203 studies were identified for screening, and 25 studies were eligible. The quality assessment rated four (16%) of the study as being of strong quality and 21 (84%) of these studies as being of moderate quality. The pendulum appliances showed mean molar distalization of 2-6.4 mm, distal tipping of molars from 6.67° to 14.50° and anchorage loss with mean premolar and incisor mesial movement of 1.63-3.6 mm and 0.9-6.5 mm, respectively. The bone anchored pendulum appliances (BAPAs) showed mean molar distalization of 4.8-6.4 mm, distal tipping of molars from 9° to 11.3° and mean premolar distalization of 2.7-5.4 mm. CONCLUSIONS: Pendulum and modified pendulum appliances are effective in molar distalization. Pendulum appliance with K-loop modification, implant supported pendulum appliance and BAPA significantly reduced anchorage loss of the anterior teeth and distal tipping of the molar teeth.


Asunto(s)
Maloclusión de Angle Clase II/terapia , Métodos de Anclaje en Ortodoncia/métodos , Aparatos Ortodóncicos/estadística & datos numéricos , Técnicas de Movimiento Dental/instrumentación , Diente Premolar/fisiopatología , Cefalometría , Femenino , Humanos , Incisivo/fisiopatología , Masculino , Diente Molar/fisiopatología
17.
Am J Orthod Dentofacial Orthop ; 151(4): 718-726, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28364895

RESUMEN

INTRODUCTION: Permanent first molars (PFM) with a poor prognosis are routinely extracted in children throughout the United Kingdom. National guidelines suggest that to achieve spontaneous closure for the mandibular arch, the PFM should be extracted at 8 to 10 years of age, during bifurcation formation of the second molar. The literature is of limited quality and has suggested alternative variables that may be associated with successful space closure. Our aim was to investigate the radiographic prognostic factors associated with space closure after extraction of PFM. Two objectives of the research are reported in this article: to determine factors that might predict space closure of the second molar after extraction of the PFM, and to develop a tool kit to aid clinical decision making. METHODS: We assessed 148 maxillary and 153 mandibular PFM extracted from 81 participants retrospectively. Dental age, second molar developmental stage, second premolar and second molar angulations, and presence or absence of the third molar were assessed on the preextraction orthopantomograms. Outcome was assessed via visual examination, study models, or radiographs. RESULTS: Closure occurred in 89.9% of the maxillary and 49.0% of the mandibular quadrants. Dental age was statistically, but not clinically, significant in the maxillary arch (P <0.05). For the mandibular arch, presence or absence of the third molar and second molar angulation were statistically and clinically significant (P <0.01 and P <0.05, respectively). A tool kit was developed in relation to the mandibular arch variables. CONCLUSIONS: These findings are contradictory to the Royal College of Surgeons guidelines and suggest that the presence of the third molar and a mesially angulated second molar are favorable for space closure. The developed tool kit requires further validity testing.


Asunto(s)
Diente Molar/cirugía , Extracción Dental , Migración del Diente/etiología , Niño , Femenino , Humanos , Masculino , Diente Molar/diagnóstico por imagen , Diente Molar/fisiopatología , Pronóstico , Radiografía Panorámica , Estudios Retrospectivos , Migración del Diente/diagnóstico por imagen
18.
Cient. dent. (Ed. impr.) ; 14(1): 19-23, ene.-abr. 2017. ilus, graf
Artículo en Español | IBECS | ID: ibc-161882

RESUMEN

El objetivo de la presente investigación fue estudiar los signos patológicos observados en molares temporales en los que se había realizado una pulpotomía. Material y método. Fueron evaluadas 79 radiografías intraorales de molares en los que se había realizado una pulpotomía. Se estudiaron los patrones de reabsorción radicular interna y externa y la presencia de lesiones radiolúcidas en la furca. Resultados. La reabsorción radicular interna patológica fue observada en el 43% de los molares temporales y la reabsorción radicular externa patológica, en el 34,2% del total de la muestra. Las lesiones radiolúcidas de la furca radicular estuvieron presentes en el 39,1% de los molares deciduos. Conclusiones. La manifestación radiográfica más frecuente fue la reabsorción radicular interna patológica. Sin embargo, este fracaso radiográfico puede ser considerado tan solo un efecto secundario, si no se acompaña de manifestaciones clínicas y no compromete la función del diente hasta su exfoliación fisiológica (AU)


Objective. The study of pathological signs observed in temporary molars that received pulpotomy treatment. Material and method. 79 intraoral x-ray of temporary molars that received pulpotomy treatment were evaluated. The patterns of internal and external root resorption and the presence of radiolucent lesions in the fork were studied. Results. The internal pathological root resorption was observed in 43% of the molars and pathologic external root resorption in 34.2% of the total sample. Radiolucent furcation lesions were present in 39.1% of deciduous molars. Conclusions. The most common radiographic manifestation was pathological internal root resorption. however, this radiographic failure can be considered as only a side effect, if it is not accompanied by clinical manifestations and does not compromise the function of the tooth until its physiological exfoliation (AU)


Asunto(s)
Humanos , Niño , Diente Primario , Enfermedades de la Pulpa Dental , Diente no Vital , Radiografía Dental , Pulpotomía , Resorción Radicular , Diente Molar/fisiopatología
19.
Eur J Orthod ; 39(5): 541-546, 2017 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-28339790

RESUMEN

Objectives: To assess the potential effects of casein phosphopeptides (CPPs) on orthodontically induced iatrogenic root resorption (OIIRR) and orthodontic teeth movement. Materials and methods: Forty Wistar rats (aged 11 weeks) were randomly divided into experimental group (EG; n = 20) that received a diet supplemented with CPP and control group (CG; n = 20) devoid of diet supplement. A 150 g force was applied using nickel titanium (NiTi) coil that was bonded on maxillary incisors and extended unilaterally to a maxillary first molar. At Day 28, animals in both groups were euthanized. Volumetric assessment of root resorption craters and linear measurement of maxillary first molars movement were blindly examined using a micro-computed tomography scan. Results: Nine rats were excluded from the experiment due to loss during general anesthesia or appliances' failure. Intra-operator reproducibility was high in both volumetric and linear measurements, 92.8 per cent and 98.5-97.6 per cent, respectively. The results reveal that dietary CPP has statistically insignificant effect on the overall OIIRR and orthodontic movement. Conclusions: CPP seems to have statistically insignificant effect on the volume of OIIRR and orthodontic movement in rats. A long-term study with larger sample size using a different concentration of CPP is required to clarify the dentoalveolar effect of CPP.


Asunto(s)
Caseínas/uso terapéutico , Fosfopéptidos/uso terapéutico , Resorción Radicular/prevención & control , Técnicas de Movimiento Dental/efectos adversos , Aleaciones , Animales , Aleaciones Dentales , Suplementos Dietéticos , Incisivo/fisiopatología , Masculino , Diente Molar/fisiopatología , Ratas , Ratas Wistar , Reproducibilidad de los Resultados , Resorción Radicular/etiología , Técnicas de Movimiento Dental/métodos , Microtomografía por Rayos X/métodos
20.
Am J Orthod Dentofacial Orthop ; 151(3): 572-582, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28257742

RESUMEN

A 22-year-old woman came with a unilateral missing mandibular first molar and buccal crossbite. The open space was closed by protraction of the mandibular left second molar and uprighting and protraction of the horizontally impacted third molar using temporary skeletal anchorage devices, and her buccal crossbite was corrected with modified palatal and lingual appliances. The total active treatment time was 36 months. Posttreatment records after 9 months showed excellent results with a stable occlusion.


Asunto(s)
Maloclusión/fisiopatología , Maloclusión/terapia , Tercer Molar/fisiopatología , Cierre del Espacio Ortodóncico/métodos , Diente Impactado/fisiopatología , Diente Impactado/terapia , Femenino , Humanos , Diente Molar/fisiopatología , Métodos de Anclaje en Ortodoncia/instrumentación , Aparatos Ortodóncicos , Radiografía Panorámica , Adulto Joven
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