ABSTRACT
AIMS: To analyze the density of the midpalatal suture by means of digital radiographs three months after retention to evaluate if this period of retention is really sufficient for bone repair. MATERIALS AND METHODS: This prospective study consisted of 31 patients (11 girls and 20 boys) in the mixed or permanent dentition stage, treated using a tooth-tissue borne expanders (Haas). Occlusal digital radiographs were taken at three stages: prior to rapid maxillary expansion (Stage I); immediately after desired maxillary expansion (Stage II); and after three months of retention (Stage III). Radiographs were taken on a dental X-ray machine, set at 70 kVp and 7 mA with an exposure time of 0.04 s. A phosphor storage plate system, imaging plate size n. 2 (35 × 45 × 1.6 mm), was used. Three regions (A, B and C) measured 0.02 mm² were selected for optical density analysis. The difference between the measurements was evaluated with the paired t-test. RESULTS: The optical density was reduced at Stages II and III compared with Stage I. Between-stage comparison showed statistically significant changes for all variables (P < 0.05), with the highest mean optical density at Stage I and the lowest at Stage II, in all groups. Actually, there was an increase in optical density between Stages II and III, but they are reduced compared with Stage I. CONCLUSION: The results strongly suggest that bone formation did not occur as expected, and that a longer retention period for bone repair may be necessary.
Subject(s)
Cranial Sutures/diagnostic imaging , Palatal Expansion Technique , Palate/diagnostic imaging , Radiography, Dental, Digital/methods , Adolescent , Bone Density/physiology , Child , Female , Follow-Up Studies , Humans , Male , Orthodontic Appliance Design , Osteogenesis/physiology , Palatal Expansion Technique/instrumentation , Prospective Studies , Radiography, Dental, Digital/instrumentation , X-Ray Intensifying ScreensABSTRACT
O objetivo foi validar e comprovar a eficácia das ferramentas de medidas com e sem calibração de três sistemas de radiografias digitais (RVG, Visualix e Digora). Para tanto utilizamos 20 dentes humanos secos provindos do Banco de Dentes Permanentes da FOUSP, os quais foram radiografados com o auxílio de três sistemas de radiografia digital dos tipos direto e semidireto. O padrão ouro das medidas dos dentes foi a verificação das dimensões dos dentes por meio de um paquímetro digital e posteriormente comparados os seus padrões de medidas com os softwares dos respectivos sistemas. Os resultados foram analisados estatisticamente pelo teste ANOVA (métodos de Tukey e Dunnett), chegando às seguintes conclusões: existiu diferença significante entre as ferramentas de medição dos aparelhos avaliados (p<0,001); a média das medidas obtidas com o aparelho Digora foi menor do que as médias obtidas pelos outros aparelhos e quando comparado ao padrão ouro; as médias das medidas obtidas com os aparelhos Visualix e RVG não apresentaram diferença estatisticamente entre eles e quando comparadas com padrão ouro.
