Efficacy and Accuracy of Maxillary Arch Expansion with Clear Aligner Treatment.

The aim of this work was to evaluate the efficacy and accuracy of maxillary arch transverse expansion using the Invisalign® clear aligner system without auxiliaries other than Invisalign attachments. Knowing the accuracy of a movement through a clear aligner system allows the clinician to plan the treatment with greater precision and to achieve the expected result faster. The study group included 28 patients with a mean age of 17 ± 3.2 years. The treatment protocol for all the selected patients included the application of the Invisalign® clear aligner system without auxiliaries, except for the Invisalign® attachments; in no case were tooth extraction or interproximal enamel reduction (IPR) performed. Linear measurements of the expansion were assessed before treatment (T0), at the end of treatment (T1), and on final virtual models by ClinCheck® (TC). A paired t-test was used to compare T0-T1 and T1-TC differences. A paired t-test was applied, and one normality was validated with the Shapiro-Wilks test. If normality was not met, the nonparametric test (Mann-Whitney U test) was applied. The level of significance was set at 5%. Statistically significant differences were found for all measurements at T0-T1. The results showed an average accuracy of efficacy of 70.88%. The differences in predictability between the various vestibular measurements (intercanine, inter-premolar, and intermolar) were not statistically significant, while they were for gingival measurements. The overall accuracy of the expansion treatment was 70%, regardless of tooth type.

Temporomandibular disorders in Venezuelan and Italian adolescents.

OBJECTIVE: The aim of this research was to compare the prevalence of temporomandibular disorders (TMDs) among Venezuelan and Italian adolescents. METHODS: One hundred-seventeen Venezuelan and 138 Italian adolescents aged 11-18 years were examined according to the Diagnostic Criteria for TMDs (DC/TMD). Signs and symptoms were registered. RESULTS: TMD prevalence among Venezuelan adolescents (17.9%) was lower than that among Italian adolescents (29.7%) and was higher in females and in the 15-18 age group. Intra-articular disorders were the most frequent in Venezuelan (8.5%) and Italian adolescents (13.0%). Pain-associated disorders were more frequent in the 11-14 age group, while intra-articular disorders were more frequent in the 15-18 age group in both samples. Italian adolescents presented greater muscle pain and joint noise than Venezuelan adolescents. CONCLUSION: TMD prevalence in Venezuelan adolescents was lower than that in Italian adolescents. This suggests the involvement of cultural and/or genetic factors in the etiology of these disorders.

Correlation between condylar size on CT and position of the articular disc on MRI of the temporomandibular joint.

Objective: To analyze the relationship between the size of the mandibular condyle and the temporomandibular joint disc position using computed tomography and magnetic resonance imaging.Methods: One hundred joints were retrospectively analyzed. The measures analyzed included the condylar head height, the medio-lateral and antero-posterior dimensions of the condylar head, and the TMJ disc position. ANOVA correlation coefficient and Tukey's post hoc test were employed.Results: The mean age of the subjects was 20.3 years. There were no significant correlations between the disc position in closed-mouth and the condylar head sizes. There was no significant correlation between the position of the disc in open mouth and the height of the condylar head, but there were statistically significant associations between the position of the disc and the horizontal condylar dimensions, the medial-lateral (p < .014), and the anterior-posterior sizes (p < .020).Conclusion: The condylar head size was smaller in subjects with disc displacement without reduction.

Unilateral condylar hyperplasia: a thee-dimensional CBCT morphometric and volumetric evaluation of mandibular condyle by open-source softwares / Hiperplasia condilar unilateral: evaluación morfométrica y volumétrica en TCHC tridimensional del cóndilo mandibular mediante softwares de código abierto

SUMMARY: Unilateral condylar hyperplasia (UCH) is an alteration of the mandibular condyle growth. The aim of this study was to evaluate condyle volume, surface area, and Morphological Index (MI) differences between the affected condyle and an unaffected one in patients with UCH, evaluated through 3D reconstructions cone beam computed tomography (CBCT) images by two open-source softwares. A retrospective cross-sectional study of 16 patients with a certain UCH, 9 females and 7 males with mean age 25.13 ± 6.8 years was made. The image obtained from the CBCT of each condyle were reconstructed using the open-source software 3D SLICER 4.6 ®. The volumetric and area measurements of the 3D reconstruction of the mandibular condyle were made using the open-source soft- ware NETFABB basic 5.0 ®. The mean condylar volume of the hyperplastic condyles was 2.07 ± 1.51 cm3 and the non-hyperplastic condyles was 1.16 ± 0.82 cm3 (p<0.05). The mean area surface of the hyperplastic condyle was 11.77 ± 3.71 cm2 and the non-hyperplasic condyle mean was 8.05 ± 2.17 cm2 (p < 0.05). The mean area surface difference was 3.72 ± 3.57 cm2 (28.0 %). The MI of the hyperplastic condyle was 1.8 ± 0.3 mm and the non-affected condyle was 1.3 ± 0.6 mm (p < 0.05). The use of open-source software for 3D reconstruction with manual segmentation for evaluation of the volume and the condylar surface is a valid tool available to the clinic in the diagnosis and monitoring of patients with condylar hyperplasia.

RESUMEN: La hiperplasia condilar unilateral (HU) es una alteración del crecimiento del cóndilo mandibular. El objetivo de este estudio fue evaluar en pacientes el volumen del cóndilo, el área de superficie y las diferencias del índice morfológico (IM) entre el cóndilo afectado y el no afectado en pacientes, mediante tomografía computarizada de haz cónico (TCHC), por medio de dos softwares. Se realizó un estudio transversal retrospectivo de 16 pacientes con determinada HU, 9 mujeres y 7 hombres con edad media 25,13 ± 6,8 años. La imagen obtenida del TCHC de cada cóndilo se reconstruyó utilizando el software de código abierto 3D SLICER 4.6 ®. Las medidas volumétricas y de área de la reconstrucción 3D del cóndilo mandibular se realizaron utilizando el software de código abierto NETFABB basic 5.0 ®. El volumen condilar medio de los cóndilos hiperplásicos fue de 2,07 ± 1,51 cm3 y el de los cóndilos no hiperplásicos fue de 1,16 ± 0,82 cm3 (p <0,05). La superficie media del cóndilo hiperplásico fue de 11,77 ± 3,71 cm2 y la media del cóndilo no hiperplásico fue 8,05 ± 2,17 cm2 (p <0,05). La diferencia de superficie de área media fue 3,72 ± 3,57 cm2 (28,0 %). El IM del cóndilo hiperplásico fue de 1,8 ± 0,3 mm y el cóndilo no afectado fue de 1,3 ± 0,6 mm (p <0,05). Para el clínico, el uso de software de código abierto en la reconstrucción 3D con segmentación manual, para la evaluación del volumen y la superficie condilar, es una herramienta efectiva en el diagnóstico y tratamiento de pacientes con hiperplasia condilar.

Association between temporomandibular joint disc position evaluated by magnetic resonance imaging and mandibular condyle inclination evaluated by computed tomography.

Temporomandibular joint disc displacement is common in the world's population and could be associated with bone and functional characteristics of the temporomandibular joint. The aim of these study was to analyse the association between temporomandibular joint disc position evaluated by magnetic resonance imaging (MRI) and the inclination of the mandibular condyle evaluated by computed tomography (CT). One hundred and seventy temporomandibular joints (TMJ) were retrospectively analysed. The temporomandibular disc position was evaluated by MRI and classified into three types: normal (N), disc displacement with reduction (DDWR) and disc displacement without reduction (DDWoR). The mandibular condyle measurements evaluated by CT included horizontal, sagittal and coronal inclination. ANOVA followed by post hoc Tukey's test was used to evaluate the interaction between condylar inclination and disc position. There was an association between disc position and the horizontal and sagittal condylar inclination (P < .05). There are statistically significant differences in the mean of horizontal and sagittal inclination of the mandibular condyle between the DDWoR and the other disc positions (P = .002 and P = .004). Disc position was not statistical associated with coronal inclination of condyle (P > .05). These results indicate that the inclination of the mandibular condyle may be different in TMJ with various disc position. A more medial horizontal inclination and a more posterior sagittal inclination of the mandibular condyle are associated with DDWoR.