Evaluation of the follicular space volume of lower third molars with different impaction positions and angulations: A cone-beam computed tomography and histopathological study.

Objective: To quantify the volume of the follicular spaces of impacted lower third molars (ILTMs) with different impaction positions and angulations using cone-beam computed tomography (CBCT) and to determine its association with the histopathological findings. Study design: This study included 103 ILTMs of 33 men and 70 women aged 18-46 years (mean age, 29.18 years). The follicular space volumes were measured on CBCT by manual segmentation and correlated with the histopathological diagnosis of each ILTM having different impaction positions and angulations. Statistical Product and Service Solutions, version 24, was used for statistical analyses by applying the t-test and binary logistic regression and multiple linear regression tests (p < 0.05). Results: Overall, 83 (80.6%) dental follicles presented a non-pathological diagnosis (mean follicular volume, 0.10 cm3), whereas 20 (19.4%) presented a pathological diagnosis (mean follicular volume, 0.32 cm3; p = 0.001). Similarly, the impaction depth in Position C cases was associated with a pathological diagnosis (p = 0.010). Conclusion: The follicular volume of the ILTMs varied significantly in teeth with a histopathological diagnosis of a follicular cyst and was associated with the impaction depth, mainly in Position C cases, and its relationship with the mandibular ramus. A mean follicular volume of 0.32 cm3 was associated with a greater probability of a pathological diagnosis.

Effects of exposure parameters on detecting clear and unclear mandibular canals using two digital intra-oral sensors - An experimental study.

Aim: To evaluate the effects of exposure parameters (tube current and voltage) to detect clear and unclear mandibular canals (MCs) using a complementary metal-oxide semiconductor (CMOS) or photo-stimulable phosphor plate (PSP) sensors. Methods: A total of 24 dry half-mandibles were divided into two groups with clear (n = 16) and unclear (n = 8) MCs. The retro-alveolar parallel technique was performed in the six-molar region of the mandibles using direct and indirect digital intra-oral sensors. Six combinations of tube voltage (kV) (60 kV, 66 kV, and 70 kV) and tube current (mA) (2 mA, 5 mA, and 8 mA) were applied, and 144 images of each group were obtained with each CMOS and PSP sensor. Images were processed using Image J software. To evaluate diagnostic accuracy, two square images of the first-molar region were obtained from each image, one with the MC inside and the other without the MC (a total of 576 images were observed). Three radiologists diagnosed the presence or absence of MCs. The diagnostic accuracy of each exposure parameter was compared with the area under the curve (Az) in receiver-operating characteristic analysis. Results: The Az values for clear MCs were higher than those for unclear MCs (P < 0.001). There were no significant differences when the tube current was modified. For unclear MCs, the Az increased when higher tube voltages were used, showing a significant difference using the PSP sensor (p = 0.004). There was no significant difference for clear MCs. Conclusions: Lower exposure parameters should be used for clear MCs, while higher tube voltage values should be used for unclear MCs.

Semi-longitudinal Study of the Mcnamara Cephalometric Triangle in Class II and Class III Subjects Grouped by Cervical Vertebrae Maturation Stage.

The aim was to compare the McNamara cephalometric triangle values in untreated normodivergent Class II and Class III malocclusion subjects of Latin American origin grouped by cervical vertebrae maturation stage to an untreated Class I malocclusion normodivergent control group. The study was conducted on a sample of 610 pretreatment lateral cephalograms (250 male, 360 female), examined and grouped according to their anteroposterior skeletal relationship (Class I, II or III), cervical vertebrae maturation stage (Pre Pubertal Peak P1 = CS1 and CS2, Pubertal Peak P2= CS3 and CS4, and Post Pubertal Peak P3 = CS5 and CS6) and sex. Co-A, Co-Gn and ENA-Me were measured in each lateral cephalogram. ANOVA and Tukey HSD post-hoc tests were performed to determine differences between the groups. The results showed that in males, the greatest maxillary and mandibular dimensional increases occurred during the P3 stage (CS5 to CS6), while in females, they occurred in the P2 stage (CS3 to CS4). The Co-A and Co-Gn showed significant differences between the malocclusion classes (p<0.05). The maxillary lengths in Class II subjects and the mandibular lengths in Class III subjects were already higher at the beginning of the period evaluated (P1). A worsening trend for the Class II and III malocclusions was identified during the period evaluated. Finally, changes in the McNamara cephalometric triangle values were markedly different in the three normodivergent skeletal malocclusion classes. In these Latin American subjects the pubertal growth spurt occurred at different times with respect to the Caucasian and Asian norms.

El objetivo del estudio fue comparar los valores del triángulo cefalométrico de McNamara en sujetos normodivergentes no tratados con maloclusión de Clase II y Clase III de origen latinoamericano agrupados por estadío de maduración de vértebras cervicales, en comparación con un grupo control sin tratamiento, normodivergentes y con maloclusión de Clase I. El estudio se realizó sobre una muestra de seiscientos diez cefalogramas laterales de cabeza pretratamiento (250 hombres, 360 mujeres) que fueron agrupados de acuerdo a su relación esquelética sagital (Clase I, II ó III), estadío de maduración vértebras cervicales (pre pico puberal P1 = CS1 y CS2, pico puberal P2 = CS3 y CS4, y post pico puberal P3 = CS5 y CS6) y sexo. Se midió en cada cefalograma el triángulo cefalométrico de McNamara Co-A, Co-Gn y ENA-Me. Se realizaron las pruebas de ANOVA y post-hoc Tukey HSD para determinar las diferencias entre grupos.Los resultados en hombres muestran que los mayores aumentos maxilares y mandibulares se produjeron durante la etapa P3 (CS5 para CS6), mientras que en las mujeres se produjeron en la etapa P2 (CS3 para CS4). Las distancias Co-A y Co-Gn muestran diferencias significativas entre las diferentes clases (p <0,05). La longitud maxilar de los sujetos de Clase II y la longitud mandibular de los sujetos de Clase III estuvieron aumentadas al inicio del período evaluado (P1). Se identificó una tendencia al empeoramiento de las maloclusiones de Clase II y III durante el período evaluado. Finalmente los cambios en los valores del triángulo cefalo- métrico de McNamara fueron marcadamente diferentes en las tres clases de maloclusión en sujetos normodivergentes. En estos sujetos latinoamericanos el estirón puberal se produjo en momentos diferentes con respecto a la raza caucásica y las normas asiáticas.

Duration of the peak of adolescent growth spurt in class i and ii malocclusion subjects using a cervical vertebrae maturation analysis.

The aim of the present work was to determine the duration of the adolescent peak growth spurt using cervical vertebral maturation analysis in class I and II malocclusion subjects. The study was conducted on a sample which consisted of 154 lateral cephalograms of children and adolescents aged 9-15 years (84 females and 70 males). The evaluation of skeletal maturation stage was performed using a visual morphological analysis of CS3 and CS4 cervical vertebrae. The sagittal skeletal relation was evaluated according to Steiner analysis. Descriptive statistics were used to summarize chronological age in each malocclusion group and for each CS3 and CS4 skeletal maturation stage. Due to a lack of normal distribution, comparisons of CS3 and CS4 age intervals on class I and II subjects were compared using the Mann-Whitney U test for independent samples. The results show that the mean duration of the adolescent peak growth spurt was 10 months between CS3 and CS4 stages in class I malocclusion subjects, whereas in class II malocclusion patients the duration was 6 months. This difference of 4 months was statistically significant (p<0.001). Finally, a clinically significant difference of 4 months in the duration of the adolescent peak growth spurt for class I and II malocclusion subjects was identified.

Duration of the peak of adolescent growth spurt in Class I and II malocclusion subjects using a cervical vertebrae maturation analysis

El objetivo de la investigación fue determinar la duración del pico de crecimiento puberal a través del análisis de maduración de vértebras cervicales en adolescentes con maloclusiónde Clase I y II. La muestra de estudio estuvo constituida por 154 cefalogramaslaterales de niños y adolescentes de 9-15 años de edad (84 mujeres y 70 hombres). Se realizó la evaluación de la etapa de maduración de las vértebras cervicales mediante el análisismorfológico visual (CS3 y CS4). Se evaluó la relación esquelética sagital de acuerdo al método de Steiner. Se realizóla estadística descriptiva para la edad cronológica en cada grupo de maloclusión y para cada etapa de maduración esquelética CS3 y CS4. Debido a la falta de distribución normalpara las comparaciones de los intervalos de edad en CS3 y CS4 en sujetos de Clase I y II se utilizó la prueba de U deMann -Whitney para muestras independientes. Los resultados muestran que el promedio de duración del pico máximo de crecimiento puberal fue de 10 meses entre las etapas CS3 y CS4 en el grupo de maloclusiónde Clase I, mientras que en el grupo de maloclusión de Clase II la duración fue de 6 meses. Esta diferencia de 4 meses fue estadísticamente significativa(p< 0.001). Finalmente se identificó una diferencia clínicamente significativade 4 meses en la duración del período del pico de crecimiento puberal entre los adolescentes con maloclusión de Clase I y II...

Duration of the peak of adolescent growth spurt in class i and ii malocclusion subjects using a cervical vertebrae maturation análisis. / Duration of the peak of adolescent growth spurt in class i and ii malocclusion subjects using a cervical vertebrae maturation análisis.

The aim of the present work was to determine the duration of the adolescent peak growth spurt using cervical vertebral maturation analysis in class I and II malocclusion subjects. The study was conducted on a sample which consisted of 154 lateral cephalograms of children and adolescents aged 9-15 years (84 females and 70 males). The evaluation of skeletal maturation stage was performed using a visual morphological analysis of CS3 and CS4 cervical vertebrae. The sagittal skeletal relation was evaluated according to Steiner analysis. Descriptive statistics were used to summarize chronological age in each malocclusion group and for each CS3 and CS4 skeletal maturation stage. Due to a lack of normal distribution, comparisons of CS3 and CS4 age intervals on class I and II subjects were compared using the Mann-Whitney U test for independent samples. The results show that the mean duration of the adolescent peak growth spurt was 10 months between CS3 and CS4 stages in class I malocclusion subjects, whereas in class II malocclusion patients the duration was 6 months. This difference of 4 months was statistically significant (p<0.001). Finally, a clinically significant difference of 4 months in the duration of the adolescent peak growth spurt for class I and II malocclusion subjects was identified.

Spatial analysis of condyle position according to sagittal skeletal relationship, assessed by cone beam computed tomography.

BACKGROUND: The study aims to compare the condylar position in patients with different anteroposterior sagittal skeletal relationships through a cone beam computed generated tomography (CBCT) imaging generated space analysis. METHODS: This was a retrospective study of clinically justified, previously taken CBCT images of 45 subjects. Based on a proper sample calculation, three groups of 15 CBCT images each were made according to their ANB angle and facial pattern: class I (normo facial pattern) and class II and III (long facial pattern). The CBCT images were of adult patients between 18 and 35 years old, with full permanent dentition at maximum occlusal intercuspidation. Anatomical references previously used by Ricketts for the condyle position inside the glenoid fossae were measured digitally through the EzImplant software. Analysis of variance, Tukey's, Kruskal-Wallis, and Mann-Whitney U statistical tests were used. RESULTS: The upper distance of the condyle to the glenoid fossa was smaller in the class II and class III compared with the class I group. The anterior distance of the condyle to the articular eminence showed significant differences when comparing the class I with the class II and class III groups. No statistically significant difference was noted in the posterior condylar distance between the groups. The angle of the eminence showed differences between the three groups, while the eminence height showed significant difference when comparing the class I with class III group. CONCLUSIONS: Spatial differences existed for the condylar position in relation to the glenoid fossa for skeletal class I, class II, and class III, but these spatial differences may not be clinically relevant.