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Orthod Craniofac Res ; 26(4): 618-631, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36975738


OBJECTIVES: To analyse the morphometric changes in the anterior alveolar bone of both the maxilla and mandible after space closure and retention for 18-36 mo in adults and adolescents. MATERIALS AND METHODS: Forty-two subjects with 4 first premolars extracted followed by retracting anterior teeth were included and divided into two age groups: adult group (4 males, 17 females, mean age: 23.67 ± 5.29 y, treatment duration: 27.95 mo, retention duration: 26.96 mo, ANB: 4.8 ± 2.1, U1-L1: 117.2 ± 9.2, U1-PP: 120.2 ± 7.2, L1-MP: 99.2 ± 5.3) and adolescent group (6 males, 15 females, mean age: 11.52 ± 1.21 y, treatment duration: 26.18 mo, retention duration: 25.79 mo, ANB: 5.2 ± 2.1, U1-L1: 116.0 ± 8.6, U1-PP: 119.8 ± 4.9, L1-MP: 99.7 ± 4.9). Alveolar bone height and thickness of anterior teeth in both groups were measured using cone beam computed tomography (CBCT) imaging performed at the pretreatment (T1), posttreatment (T2) and retention phases (T3). One-way repeated-measure ANOVAs were performed to evaluate the alveolar bone changes. Voxel-based superimpositions were performed to measure the amount of tooth movement. RESULTS: After orthodontic treatment, the lingual bone height and thickness of both arches and the labial bone height of the mandible decreased significantly in both age groups (P < .05). Most of the labial bone height and thickness of the maxilla in both groups remained unchanged (P > .05). After retention, the lingual bone height and thickness increased significantly in both age groups (P < .05). The amounts of increased height ranged from 1.08 to 1.64 mm in adults and from 0.78 to 1.21 mm in adolescents, and the amounts of increased thickness ranged from 0.23 mm to 0.62 mm in adults and from 0.16 mm to 0.36 mm in adolescents. Obvious movements of the anterior teeth during retention were not found (P > .05). CONCLUSIONS: Although lingual alveolar bone loss occurred in adolescents and adults during orthodontic treatment, continuous remodelling occurred in the later retention phase, which provides a reference for clinical treatment planning of bimaxillary dentoalveolar protrusion.

Incisivo , Má Oclusão , Masculino , Feminino , Humanos , Adulto , Adolescente , Adulto Jovem , Criança , Estudos Retrospectivos , Dente Pré-Molar/diagnóstico por imagem , Maxila/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico
Orthod Craniofac Res ; 25(2): 174-182, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34320269


OBJECTIVES: To evaluate the morphometric changes in maxillary and mandibular anterior alveolar bone after orthodontic treatment and retention for 18-24 months by cone-beam computed tomography (CBCT). SETTING AND SAMPLE POPULATION: Thirty-four adolescent patients (12 males and 22 females; mean age: 14.29 ± 1.24 years) diagnosed with bimaxillary dentoalveolar protrusion and with extractions of the 4 first premolars were included. MATERIALS AND METHODS: The labial and lingual (palatal) alveolar bone thickness, height and root length of the maxillary and mandibular anterior teeth were assessed using CBCT imaging at the pre-treatment (T1), post-treatment (T2) and retention phases (T3). Voxel-based superimpositions of the T2 and T3 images were performed, and the distances of incisal and apical movement between T2 and T3 were measured to determine whether relapses occurred. RESULTS: After orthodontic treatment, the labial and lingual (palatal) bone height decreased significantly (P < .05) and the labial thickness at the crestal (L1), midroot (L2), and apical levels (L3) had no significant change, while the lingual (palatal) bone thickness at all three levels decreased significantly (P < .05). After 18-24 months of retention, the lingual (palatal) height and the lingual (palatal) thickness at the crestal (L1) level increased significantly (P < .05). There were no obvious incisal and apical movements of the anterior teeth between T2 and T3 (P > .05), indicating that no relapses occurred. CONCLUSIONS: Even though lingual (palatal) alveolar loss occurred due to the orthodontic treatment, the cervical alveolar bone seemed to recover over time. Therefore, appropriate camouflage treatment can be used in patients with bimaxillary dentoalveolar protrusion, and this treatment will not irreversibly deteriorate periodontal health and affect the orthodontic treatment stability.

Incisivo , Má Oclusão , Adolescente , Dente Pré-Molar/diagnóstico por imagem , Dente Pré-Molar/cirurgia , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Má Oclusão/diagnóstico por imagem , Má Oclusão/terapia , Mandíbula , Maxila , Estudos Retrospectivos
BMC Oral Health ; 22(1): 200, 2022 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-35606730


BACKGROUND: This study aimed to compare the age-related positional and morphological characteristics of the temporomandibular joint (TMJ) between individuals with anterior openbite or crossbite and controls. METHODS: This multi-cross-sectional comparative study analysed cone-beam computed tomography images of 750 participants, equally divided into the openbite, crossbite, and control groups (OBG, CBG, and CG, respectively). Each group was further divided into five subgroups (8-11 years, 12-15 years, 16-19 years, 20-24 years, and 25-30 years). Measurements of the TMJ included the position of the condyles in their respective fossae and morphology of the condyles and fossae. Data were submitted to statistical analysis. The study adhered to the STROBE Statement checklist for reporting of cross-sectional studies. RESULTS: Condyles were positioned more posteriorly with increasing age in all groups, and the condylar position was more posterior in the OBG than in the CBG. The articular eminence inclination increased with age in all the groups. There were significant differences in the articular eminence inclination among the three major groups at the age of > 15 years, and the condylar path was flatter in the CBG than in the OBG. CONCLUSIONS: Age-related morphological and positional characteristics of the TMJ differed considerably among OBG, CBG and CG. Contrary to CBG, OBG was found to have relatively posterior condylar position and steeper condylar path.

Má Oclusão , Mordida Aberta , Adolescente , Humanos , Tomografia Computadorizada de Feixe Cônico , Estudos Transversais , Côndilo Mandibular , Articulação Temporomandibular/diagnóstico por imagem
J Mater Chem B ; 8(21): 4660-4671, 2020 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-32374794


The composite hydrogel of gelatin (Gel) and oxidized sodium alginate (OSA) is often used in biomedical fields due to its good biocompatibility. However, the typical utility of borax and weak mechanical properties are not preferred either in the cell environment or as a supporting scaffold. Herein, poly(vinyl alcohol) (PVA) is mixed with Gel and OSA to construct a ternary hydrogel Gel-OSA-PVA so as to improve the mechanical properties and reduce toxicity. The hydrogel possessed tunable mechanical properties by adjusting the concentrations of PVA and the oxidized degrees of OSA, related closely to the dynamic imine bonds and multiple hydrogen bonds among these macromolecules. In terms of the effects of OSA, its aldehyde group content played a more important role in enhancing the compressive modulus of hydrogels compared to its change of molecular weight/chain length. These multiple dynamic bonds also endowed the Gel-OSA-PVA hydrogel with good self-healing performance. Interestingly, the hydrogels presented great conductivity due to the existence of free ions, varying with the deformation of hydrogels, and showed great potential in promoting osteogenesis. Together with the absence of cytotoxicity and antibacterial properties, the hydrogel is a potential candidate for applications in the biomedical field.

Alginatos/química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Gelatina/química , Hidrogéis/farmacologia , Álcool de Polivinil/química , Células 3T3 , Animais , Antibacterianos/química , Células Cultivadas , Hidrogéis/química , Camundongos , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
J Biomed Nanotechnol ; 16(11): 1658-1666, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33461657


A number of bone repair materials are demanded due to bone injury in clinical treatment. Magnetic hydrogels combined with the magnetic field have showed great promoting potential in the field of bone regeneration. Considering the superiority of magnetic microspheres in magnetic localization and drug release, magnetic poly(lactic-co-glycolic acid) microspheres, obtained by electrospraying, were combined with gelatin hydrogel to construct a magnetic poly(lactic-co-glycolic acid) microsphere-gelatin hydrogel for bone repair in our study. Particularly, we investigated the combined effect of 20 mT static magnetic field and magnetic poly(lactic-co-glycolic acid) microsphere-gelatin hydrogel on the proliferation of MC3T3-E1 pre-osteoblasts, indicating that it could significantly promote cell growth at a low concentration of Fe3 O4. Furthermore, the hydrogel containing 400 mg˙ L-1Fe3 O4 presented the highest growth-promoting effect under a 20 mT static magnetic field. Therefore, the magnetic poly(lactic-co-glycolic acid) microsphere-gelatin hydrogel possesses impressive application value in promoting osteogenesis and bone repair.

Gelatina , Ácido Poliglicólico , Glicóis , Hidrogéis , Ácido Láctico , Campos Magnéticos , Fenômenos Magnéticos , Microesferas , Osteoblastos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico