16 research outputs found

    3D mandibular superimposition: Comparison of regions of reference for voxel-based registration

    Get PDF
    The aim was to evaluate three regions of reference (Björk, Modified Björk and mandibular Body) for mandibular registration testing them in a patients' CBCT sample.Mandibular 3D volumetric label maps were built from CBCTs taken before (T1) and after treatment (T2) in a sample of 16 growing subjects and labeled with eight landmarks. Registrations of T1 and T2 images relative to the different regions of reference were performed, and 3D surface models were generated. Seven mandibular dimensions were measured separately for each time-point (T1 and T2) in relation to a stable reference structure (lingual cortical of symphysis), and the T2-T1 differences were calculated. These differences were compared to differences measured between the superimposed T2 (generated from different regions of reference: Björk, Modified Björk and Mandibular Body) over T1 surface models. ICC and the Bland-Altman method tested the agreement of the changes obtained by nonsuperimposition measurements from the patients' sample, and changes between the overlapped surfaces after registration using the different regions of reference.The Björk region of reference (or mask) did work properly only in 2 of 16 patients. Evaluating the two other masks (Modified Björk and Mandibular body) on patients' scans registration, the concordance and agreement of the changes obtained from superimpositions (registered T2 over T1) compared to results obtained from non superimposed T1 and T2 separately, indicated that Mandibular Body mask displayed more consistent results.The mandibular body mask (mandible without teeth, alveolar bone, rami and condyles) is a reliable reference for 3D regional registration

    Periodontal morphology of maxillary canines orthodontically moved to the grafted alveolar cleft: a Cone-Beam Computed Tomography assessment

    No full text
    O objetivo deste trabalho foi avaliar a morfologia periodontal vestibular e lingual do canino permanente movimentado para a região enxertada em fissuras alveolares unilaterais com comprometimento do rebordo alveolar por meio de mensurações realizadas em imagens de exames de tomografia computadorizada cone-beam (TCCB). Esses valores foram comparados com o canino e incisivo lateral presentes no lado não comprometido pela fissura. A amostra consistiu de exames de TCCB de 30 pacientes com fissura unilateral em fase de contenção pós-tratamento ortodôntico. Foram realizados exames de TCCB com protocolo de FOV de 6cm, voxel de 0,25mm por 26,9 segundos. Os exames foram avaliados por apenas um ortodontista duas vezes em um intervalo de 30 dias para calcular o erro do método. A padronização da posição da cabeça foi determinada com o plano palatino paralelo ao solo. Foram realizados cortes axiais na altura da trifurcação do dente 16 para mensurar a espessura da tábua óssea vestibular e lingual do canino do lado da fissura (CF), canino do lado sem fissura (CsF) e incisivo lateral do lado sem fissura (IL). Para a avaliação do nível da crista óssea vestibular e lingual, foram realizados cortes parassagitais passando pelo centro da coroa de cada dente avaliado: CF, CsF e IL. Calculou-se a distância da junção cemento-esmalte (JCE) à crista óssea alveolar vestibular e lingual. Para a comparação dos valores do CF com o CsF e IL, foram utilizados o teste t e o teste de Wilcoxon a depender da distribuição de normalidade. A espessura da tábua óssea vestibular do CF se mostrou significantemente menos espessa do que a do CsF (p=0,002) e do que a do IL (p=0,001). Além disso, a distância da JCE à crista óssea se apresentou estatisticamente maior para o CF (p<0,001). A movimentação do canino superior permanente para a área de fissura alveolar enxertada consiste em uma opção terapêutica viável. No entanto, a condução do tratamento ortodôntico demanda cautela, incluindo uma movimentação lenta e a verificação da qualidade da mucosa ceratinizada.The purpose of this research was to assess the buccal and lingual periodontal morphology of the permanent canine moved to the grafted region in unilateral alveolar clefts with commitment of the alveolar bone by measuring images of conebeam computed tomography (CBCT) exams. These values were compared to the canine and lateral incisor present in the non-clefted side. The sample comprised CBCT exams of 30 patients with unilateral cleft lip and/or palate during retention period after orthodontic treatment. The protocol used for the CBCT exam was FOV of 6cm, voxel of 0,25mm for 26.9 seconds. The exams were assessed by one orthodontist two times with an interval of 30 days to assess intraoperator reliability. The standard position of the head was determined with the palatal plane parallel to the horizontal plane. Axial slices of the trifurcation of the right permanent molar were obtained to assess the buccal and lingual alveolar bone thickness of the canine in the clefted side (CF), the canine in the non-clefted side (CsF) and the lateral incisor in the non-clefted side (IL). To assess the buccal and lingual bone crest height, parassagital slices were obtained passing through the center of the crown of each evaluated teeth. It was calculated the distance form the cemento-enamel junction (CEJ) to the buccal and lingual alveolar bone crest. The comparison among the CF values with the CsF and IL was performed with the t test or the Wilcoxon test, depending on the distribution of normality. The buccal alveolar bone thickness of the CF is statistically thinner than the buccal alveolar bone thickness of the CsF (p=0,002) and of the IL (p=0,001). Other than that, the distance between the CEJ and the alveolar crest was significant higher for the CF (p<0,001). The movement of the upper permanent canine to the grafted alveolar consists in a viable therapeutic option. However, the orthodontic treatment demands caution, including a very slow movementation and the verification of the quality of the keratinized mucosa

    Periodontal morphology of maxillary canines orthodontically moved to the grafted alveolar cleft: a Cone-Beam Computed Tomography assessment

    No full text
    O objetivo deste trabalho foi avaliar a morfologia periodontal vestibular e lingual do canino permanente movimentado para a região enxertada em fissuras alveolares unilaterais com comprometimento do rebordo alveolar por meio de mensurações realizadas em imagens de exames de tomografia computadorizada cone-beam (TCCB). Esses valores foram comparados com o canino e incisivo lateral presentes no lado não comprometido pela fissura. A amostra consistiu de exames de TCCB de 30 pacientes com fissura unilateral em fase de contenção pós-tratamento ortodôntico. Foram realizados exames de TCCB com protocolo de FOV de 6cm, voxel de 0,25mm por 26,9 segundos. Os exames foram avaliados por apenas um ortodontista duas vezes em um intervalo de 30 dias para calcular o erro do método. A padronização da posição da cabeça foi determinada com o plano palatino paralelo ao solo. Foram realizados cortes axiais na altura da trifurcação do dente 16 para mensurar a espessura da tábua óssea vestibular e lingual do canino do lado da fissura (CF), canino do lado sem fissura (CsF) e incisivo lateral do lado sem fissura (IL). Para a avaliação do nível da crista óssea vestibular e lingual, foram realizados cortes parassagitais passando pelo centro da coroa de cada dente avaliado: CF, CsF e IL. Calculou-se a distância da junção cemento-esmalte (JCE) à crista óssea alveolar vestibular e lingual. Para a comparação dos valores do CF com o CsF e IL, foram utilizados o teste t e o teste de Wilcoxon a depender da distribuição de normalidade. A espessura da tábua óssea vestibular do CF se mostrou significantemente menos espessa do que a do CsF (p=0,002) e do que a do IL (p=0,001). Além disso, a distância da JCE à crista óssea se apresentou estatisticamente maior para o CF (p<0,001). A movimentação do canino superior permanente para a área de fissura alveolar enxertada consiste em uma opção terapêutica viável. No entanto, a condução do tratamento ortodôntico demanda cautela, incluindo uma movimentação lenta e a verificação da qualidade da mucosa ceratinizada.The purpose of this research was to assess the buccal and lingual periodontal morphology of the permanent canine moved to the grafted region in unilateral alveolar clefts with commitment of the alveolar bone by measuring images of conebeam computed tomography (CBCT) exams. These values were compared to the canine and lateral incisor present in the non-clefted side. The sample comprised CBCT exams of 30 patients with unilateral cleft lip and/or palate during retention period after orthodontic treatment. The protocol used for the CBCT exam was FOV of 6cm, voxel of 0,25mm for 26.9 seconds. The exams were assessed by one orthodontist two times with an interval of 30 days to assess intraoperator reliability. The standard position of the head was determined with the palatal plane parallel to the horizontal plane. Axial slices of the trifurcation of the right permanent molar were obtained to assess the buccal and lingual alveolar bone thickness of the canine in the clefted side (CF), the canine in the non-clefted side (CsF) and the lateral incisor in the non-clefted side (IL). To assess the buccal and lingual bone crest height, parassagital slices were obtained passing through the center of the crown of each evaluated teeth. It was calculated the distance form the cemento-enamel junction (CEJ) to the buccal and lingual alveolar bone crest. The comparison among the CF values with the CsF and IL was performed with the t test or the Wilcoxon test, depending on the distribution of normality. The buccal alveolar bone thickness of the CF is statistically thinner than the buccal alveolar bone thickness of the CsF (p=0,002) and of the IL (p=0,001). Other than that, the distance between the CEJ and the alveolar crest was significant higher for the CF (p<0,001). The movement of the upper permanent canine to the grafted alveolar consists in a viable therapeutic option. However, the orthodontic treatment demands caution, including a very slow movementation and the verification of the quality of the keratinized mucosa

    Alveolar Bone Morphology in Patients With Bilateral Complete Cleft Lip and Palate in the Mixed Dentition: Cone Beam Computed Tomography Evaluation

    No full text
    Objectives: To verify the thickness and level of alveolar bone around the teeth adjacent to the cleft by means of cone beam computed tomography (CBCT) in patients with complete bilateral cleft lip and palate prior to bone graft surgery and orthodontic intervention. Method: The sample comprised 10 patients with complete bilateral cleft lip and palate (five boys and five girls) in the mixed dentition. The mean age was 9.5 years, and all subjects showed a G3 interarch relationship according to the Bauru index. The thickness of alveolar bone surrounding the maxillary incisors and the maxillary canines was measured in CBCT axial section using the software iCAT Xoran System. The distance between the alveolar bone crest and the cement-enamel junction (CEJ) was measured in cross sections. Results: The tomography images showed a thin alveolar bone plate around teeth adjacent to clefts. No bone dehiscence was observed in teeth adjacent to clefts during the mixed dentition. A slight increase in the distance between the alveolar bone crest and the CEJ was observed in the mesial and lingual aspects of canines adjacent to cleft. Conclusion: In patients with BCLP in the mixed dentition, teeth adjacent to the alveolar cleft are covered by a thin alveolar bone plate. However, the level of alveolar bone crest around these teeth seems to be normal, and no bone dehiscence was identified at this age

    3D Mandibular Superimposition: Comparison of Regions of Reference for Voxel-Based Registration - Fig 2

    No full text
    <p><b>A</b>) Representation of the measurements obtained independently from T1 and T2 and their difference; <b>B</b>) Representation of the T2-T1 differences based on mandibular registration; <b>C</b>) Partial 3D surface model of the mandible and representation of the 8 landmarks used for the measurements.</p

    Registered T2 overlapped over T1.

    No full text
    <p><b>A</b>) Mandibular Body mask showing superimposition over T1; <b>B</b>) Modified Björk mask displayed a vertical shift of the mandibular canal in relation to T1.</p
    corecore