Morphology changes of maxillary molar distalization by clear aligner therapy / Cambios de la morfología en la distalización de molares maxilares mediante terapia con alineadores transparentes

SUMMARY: To evaluate the skeletal, dento-alveolar and soft tissue morphology changes after maxillary molar distalization by clear aligner therapy and identify the significant efficacy of molar distalization,18 patients in conformity with the inclusion criteria were selected. Pre- and post-treatment Cone Beam Computed Tomography (CBCT) were examined to measure the angular and linear parameters. All subjects were completed non-extraction clear aligner treatment by distalizing molars. A paired-t test and independent-samples t-test were performed to observe the difference between before and after treatment and the difference between the first molar and second molar respectively. P-values <0.05 were considered statistically significant. Predicted movement rate was calculated by the formula: (actual movement(mm)/planned movement(mm)) x100%. Most variables of pre- and post-treatment showed no statistical difference(P<0.05), excepting SNA angle (P<0.05) and Upper lip/E-line linear (P<0.01) due to incisor retraction. The first and second molar revealed a translation movement without significant tipping and vertical movement. Clear aligners provided a high predictability (83.44 %) of distalization the maxillary first molar, and 85.14 % of the maxillary second molar. Clear aligners can effectively achieve distal displacement of molars.

RESUMEN: Se seleccionaron 18 pacientes, de acuerdo con los criterios de inclusión, para evaluar los cambios en la morfología esquelética, dentoalveolar y de los tejidos blandos después de la distalización de los molares maxilares, mediante la terapia con alineadores transparentes e así identificar la significativa eficacia de la distalización de los molares. Se examinó a través de tomografía computarizada de haz cónico (CBCT) antes y después del tratamiento para medir los parámetros angulares y lineales. Todos los sujetos completaron el tratamiento con alineadores transparentes sin extracción mediante la distalización de los molares. Se realizó una prueba t pareada y una prueba t de muestras independientes para observar la diferencia entre antes y después del tratamiento y la diferencia entre el primer molar y el segundo molar, respectivamente. Los valores de p<0,05 se consideraron estadísticamente significativos. La tasa de movimiento prevista se calculó mediante la fórmula: (movimiento real (mm)/movimiento planificado (mm)) x 100 %. La mayoría de las variables de pre y postratamiento no mostraron diferencia estadística (P<0,05), excepto el ángulo SNA (P<0,05) y el labio superior/línea E lineal (P<0,01) debido a la retracción del incisivo. El primer y segundo molar revelaron un movimiento de traslación sin inclinación significativa y movimiento vertical. Los alineadores transparentes proporcionaron una alta previsibilidad (83,44 %) de la distalización del primer molar superior y del 85,14 % del segundo molar superior. Los alineadores transparentes pueden lograr efectivamente el desplazamiento distal de los molares.

Morphological changes of frankel functional regulator III in mixed dentition with class III malocclusion / Cambios morfológicos del regulador funcional frankel III en dentición mixta con maloclusión clase III

The aim of this study was to evaluate the hard and soft tissue profile changes following treatment of functional and mild skeletal class III malocclusion in mixed dentition by means of the Frankel functional regulator (FR-3) appliance, and to reveal the mechanism and effectiveness of treatment with FR-3 appliance. Twenty-six patients (chronological mean age, 8.7±1.4 years; mean treatment duration, 10.3±1.3 months) with functional and mild skeletal class III malocclusion were selected and treated with FR-3 appliances. Lateral cephalogram was taken pre- and post-treatment, and the data was analyzed by paired-samples t test with SPSS22.0 software package. Differences were considered statistically significant at P < 0.05. The results demonstrated that the FR-3 appliance produced a statistically significant decrease in L1-NB, L1-MP, U1-L1 (P<0.01) and an increase greatly in ANB, MP-FH, Y axis, ANSMe, ANS-Me/N-Me and overjet (P<0.01). SNA, SNB were increased significantly (P<0.05). Meanwhile, N'-Sn-Pog', ULSn-SN, LLSiSN increased, S-N'-Si, LL-EP decreased with significant difference (P<0.01). S-N'-Sn, Cm-Sn-UL, UL-EP, Sn-Mes and Ns-Mes increased with significant difference (P<0.05). Therefore it was concluded that after FR-3 treatment, the position of mandible may rotate clockwise backwards and downwards, with the labioversion of upper incisors and linguoversion of lower incisors. Although point A moved mesially, the length and position of the maxilla did not change significantly. With the protrusion of upper lip and the retrusion of lower lip, the relationship among nose, upper lip, lower lip and chin become harmonious, the profile of soft tissue is more coordinated and attractive.

El objetivo de este estudio fue evaluar los cambios en el perfil de los tejidos duros y blandos después del tratamiento de la maloclusión funcional y leve de la clase III esquelética en la dentición mixta mediante el aparato regulador funcional Frankel (FR-3), y revelar el mecanismo y efectividad del tratamiento con el aparato FR-3. Veintiseis pacientes (edad media 8,7 ± 1,4 años; duración media del tratamiento, 10,3 ± 1,3 meses) con maloclusión funcional y leve de clase esquelética III fueron seleccionados y tratados con aparatos FR-3. El cefalograma lateral se tomó antes y después del tratamiento, y los datos se analizaron mediante la prueba t de muestras con el software SPSS22.0. Las diferencias se consideraron estadísticamente significativas a P <0,05. Los resultados demostraron que el dispositivo FR-3 produjo una disminución estadísticamente significativa en L1-NB, L1MP, U1-L1 (P <0,01) y un gran aumento en ANB, MP-FH, eje Y, ANS-Me, ANS -Me / N-Me y overjet (P <0,01). SNA, SNB se incrementaron significativamente (P <0,05). Mientras tanto, N'Sn-Pog', ULSn-SN, LLSi-SN aumentaron, S-N'-Si, LL-EP disminuyeron con una diferencia significativa (P <0,01). S-N'-Sn, Cm-Sn-UL, UL-EP, Sn-Mes y Ns-Mes aumentaron con una diferencia significativa (P <0,05). Por lo tanto, se concluyó que después del tratamiento con FR-3, la posición de la mandíbula puede girar en sentido reloj hacia atrás y hacia abajo, con labioversión de los incisivos superiores y linguoversión de los incisivos inferiores. Aunque el punto A se movió mesialmente, la longitud y la posición del maxilar no cambiaron significativamente. Con la protuberancia del labio superior y la retrusión del labio inferior, la relación entre la nariz, el labio superior, el labio inferior y el mentón se armoniza, el perfil del tejido blando es más coordinado y atractivo.

Mild Encephalopathy/Encephalitis with a Reversible Splenial Lesion (MERS): A Report of Five Neonatal Cases / 华中科技大学学报（医学）（英德文版）

Mild encephalopathy/encephalitis with a reversible spleniat (MERS) lesion is a clinic-radiological entity.The clinical features of MERS in neonates are still not systemically reported.This paper presents five cases of MERS,and the up-to-date reviews of previously reported cases were collected and analyzed in the literature.Here we describe five cases clinically diagnosed with MERS.All of them were neonates and the average age was about 4 days.They were admitted for the common neurological symptoms such as hyperspasmia,poor reactivity and delirium.Auxiliary examinations during hospitalization also exhibited features in common.In this report,we reached following conclusions.Firstly,magnetic resonance imaging revealed solitary or comprehensive lesions in the splenium of corpus callosum,some of them extending to almost the whole corpus callosum.The lesions showed low intensity signal on Tl-weighted images,homogeneously hyperintense signal on T2-weighted images,fluid-attenuated inversion recovery and diffusion-weighted images,and exhibited an obvious reduced diffusion on apparent diffusion coefficient map.Moreover,the lesions in the magnetic resonance imaging disappeared very quickly even prior to the clinical recovery.Secondly,all the cases depicted here suffered electrolyte disturbances especially hyponatremia which could be easily corrected.Lastly,all of the cases recovered quickly over one week to one month and majority of them exhibited signs of infections and normal electroencephalography.

Epidemiological and molecular characterization of community and hospital acquired Staphylococcus aureus strains prevailing in Shenyang, Northeastern China

In order to obtain adequate information for the treatment of methicillin resistant Staphylococcus aureus (MRSA) infections, it is crucial to identify trends in epidemiological and antimicrobial resistance patterns of local S. aureus strains. Community and hospital acquired S. aureus isolates (n = 202) were characterized using staphylococcal cassette chromosome mec (SCCmec) typing, pulse field gel electrophoresis (PFGE) analysis, spa typing and minimal inhibitory concentration (MIC) determination. The prevalence of the Panton-Valentine leukocidine (pvl) and several antibiotic resistance genes among the isolates were also detected by PCR. All of the S. aureus isolates were susceptible to vancomycin, daptomycin and linezolid. Three hospital isolates were resistant to teicoplanin while 14 showed intermediate resistance to teicoplanin. The resistance patterns of community-acquired MRSA (CA-MRSA) isolates to other antimicrobials were similar to those of hospital-acquired MRSA (HA-MRSA) isolates except for clindamycin and gentamicin. There was excellent correlation between phenotypes and genotypes in the determination of S. aureus resistance to erythromycin, gentamicin, and tetracycline. The SCCmec type II and SCCmec type IV were the predominant types detected in hospital and community isolates, respectively. The most frequently encountered spa types were t002 and t030 both in HA-and CA-MRSA isolates. Pulsotype A was the most predominant pulsotype identified among the isolates tested, followed by pulsotype B. Seventy-two hospital isolates (19 HA-MRSA and 53 HA-MSSA) and 10 CA-MRSA were positive for the pvl gene. This study shows that the combination of susceptibility testing and various molecular methods has provided useful information on the antibiotic resistance and molecular diversity of S. aureus in a specific region of China. The high proportion of pvl positive MSSA and MRSA isolates observed in this study indicates that adequate measures are needed to curtail the spread of those MRSA and MSSA clones prevailing both in hospital and the community.