Dentoalveolar mandibular changes with self-ligating versus conventional bracket systems: A CBCT and dental cast study

OBJECTIVE: The aim of the present study was to compare dentoalveolar changes in mandibular arch, regarding transversal measures and buccal bone thickness, in patients undergoing the initial phase of orthodontic treatment with self-ligating or conventional bracket systems. METHODS: A sample of 25 patients requiring orthodontic treatment was assessed based on the bracket type. Group 1 comprised 13 patients bonded with 0.022-in self-ligating brackets (SLB). Group 2 included 12 patients bonded with 0.022-in conventional brackets (CLB). Cone-beam computed tomography (CBCT) scans and a 3D program (Dolphin) assessed changes in transversal width of buccal bone (TWBB) and buccal bone thickness (BBT) before (T1) and 7 months after treatment onset (T2). Measurements on dental casts were performed using a digital caliper. Differences between and within groups were analyzed by Student's t-test; Pearson correlation coefficient was also calculated. RESULTS: Significant mandibular expansion was observed for both groups; however, no significant differences were found between groups. There was significant decrease in mandibular buccal bone thickness and transversal width of buccal bone in both groups. There was no significant correlation between buccal bone thickness and dental arch expansion. CONCLUSIONS: There were no significant differences between self-ligating brackets and conventional brackets systems regarding mandibular arch expansion and changes in buccal bone thickness or transversal width of buccal bone. .

OBJETIVO: o objetivo do presente estudo foi comparar as alterações dentoalveolares transversais e a espessura óssea da arcada inferior em pacientes submetidos ao tratamento ortodôntico utilizando sistemas de braquetes autoligáveis ou convencionais. MÉTODOS: uma amostra de 25 pacientes requerendo tratamento ortodôntico foi recrutada com base no tipo de braquete. No Grupo 1, 13 pacientes foram tratados com braquetes autoligáveis (SLB, slot 0,022"); o Grupo 2 incluiu 12 pacientes, nos quais foram colados braquetes convencionais (CLB, slot 0,022"). Utilizou-se tomografia computadorizada de feixe cônico e um programa 3D (Dolphin) para avaliar as alterações pré-tratamento (T1) e 7 meses após o início desse (T2). As medições em modelos de gesso foram realizadas com o auxílio de um paquímetro digital. As diferenças intergrupos, bem como intragrupo, foram analisadas por meio de teste t de Student. Além disso, o coeficiente de correlação de Pearson foi utilizado. RESULTADOS: alterações dentoalveolares significativas foram observadas em ambos os grupos. Entretanto, não houve diferenças significativas entre os grupos. Houve uma diminuição da espessura óssea na região posterior e das medidas transversais em ambos os grupos. Não houve uma correlação significativa entre a espessura óssea posterior e a expansão da arcada dentária, em nenhum dos dois sistemas de braquetes utilizados. CONCLUSÕES: comparando-se o uso dos aparelhos autoligáveis e convencionais, concluiu-se que não houve diferenças dentoalveolares significativas quanto à expansão da arcada inferior e quanto à espessura óssea posterior. .

Predicting the actual length of premolar teeth on the basis of panoramic radiology.

Background: Panoramic radiography is one of the most common techniques for evaluating the jaw bones and associated structures. Aim: The aim of the study was to predict the actual length of the premolar teeth, based on measurements taken on a panoramic radiograph. Materials and Methods: This study was done in two stages. In the first stage, the actual and panoramic lengths of 102 teeth of orthodontic patients were measured and compared. In the next stage, the actual and radiographic vertical lengths of four metal balls placed in the molar and first premolar areas of 27 patients, referred to radiography clinic were also analyzed. Comparison of the mean magnification between the two methods was performed by one-sample T-test and P<0.05 was considered as statistically significant. Results: The total magnification of the premolar region in the vertical plane in the tooth length measurement method was 17.39%, while the same in the metal markers method was 27.39%. The upper teeth showed larger magnification than the lower teeth in the vertical plane. Similarly, the magnification and distortion of the metal markers in the horizontal plane were significantly more than this in the vertical plane and also their magnification and distortion in the molar region were more than this in the premolar region. The actual length of the premolar teeth can be estimated by using a suitable regression formula. Conclusion: Panoramic radiography can be used for calculating the actual length of premolar teeth.

The relative diagnostic yields of clinical, FOTI and radiographic examinations for the detection of approximal caries in youngsters.

Background: The detection of carious lesions in the initial stages of development is very important in order to prevent the occurrence of cavitation. Aims and Objectives: The aim of the present study was to compare three methods-visual examination, FOTI, and bitewing radiographic examination-for the detection of noncavitated and cavitated approximal carious lesions. Materials and Methods: Seventy students (mean age 14 years) with low caries prevalence were examined by three examiners. The tooth surfaces judged as having caries by at least one examiner or one diagnostic method were scheduled for tooth separation. Results: The results showed that the incorporation of FOTI and radiographic examination represented an additional diagnostic yield of 50% and about 110%, respectively, compared to clinical examination alone. Conclusion: We conclude that FOTI or radiographic examination, or both, used as adjuncts to clinical examination, could improve the detection of noncavitated and cavitated approximal carious lesions. Although FOTI should not replace bitewing radiographic examination, it does seem to have additional value for the detection of carious lesions on approximal surfaces of the posterior teeth in school children with low caries prevalence.