Cognitive stimulation has potential for brain activation in individuals with Rett syndrome.

BACKGROUND: Knowledge regarding neuropsychological training in Rett syndrome (RS) is scarce. The aim of this study was to assess the outcome and the duration of the effect of cognitive stimulation on topographic electroencephalography (EEG) data in RS. METHODS: Twenty female children diagnosed with RS were included in the analysis. Girls with RS conducted a cognitive task using an eye-tracker designed to evaluate access and choice skills. EEG data were acquired during the experimental procedure including two 10-min baseline stages before and after the task. Topographical changes of several EEG spectral markers including absolute and relative powers, Brain Symmetry Index and entropy were assessed. RESULTS: Topographic significance probability maps suggested statistical decreases on delta activity and increases on beta rhythm associated with the cognitive task. Entropy increased during and after the task, likely related to more complex brain activity. A significant positive interaction was obtained between Brain Symmetry Index and age showing that the improvement of interhemispheric symmetry was higher in younger girls (5-10 years). CONCLUSIONS: According to our findings, significant alterations of brain rhythms were observed during and after cognitive stimulation, suggesting that cognitive stimulation may have effects on brain activity beyond the stimulation period. Finally, our promising results also showed an increase brain symmetry that was especially relevant for the younger group. This could suggest an interaction of the eye-tracking cognitive task; however, further studies in this field are needed to assess the relation between brain asymmetries and age.

Recurrence rate of oral squamous cell papilloma after excision with surgical scalpel or laser therapy: A retrospective cohort study.

BACKGROUND: The aim was to describe the recurrence rates of Oral Squamous Cell Papilloma (OSCP) following surgical treatment with surgical scalpel and two different lasers (CO2 or Er,Cr;YSGG) and to determine the clinical and histopathologic features of these lesions. MATERIAL AND METHODS: A retrospective cohort study covering a period of 12 years (1997-2009) that included patients diagnosed of OSCP treated with surgical excision was performed. Data was processed using SPSS 22.0 (SPPS Inc. Chicago, USA) and a descriptive and bivariate analysis were conducted. RESULTS: A total of 37 histopathologically confirmed OSCP in 36 patients, 19 women (52.7%) and 17 men (47.2%) with an average age of 33.4 years (14-86 years) were included. Twenty-two cases were treated by excision with surgical scalpel excision, 11 with CO2 laser and 3 with Er,Cr:YSGG laser. The mean age was 35.4 years (14-86 years) and the distribution by gender was 19 women (52.7%) and 17 men (47.2%). The most common locations were the palate in 14 cases (37.8%), followed by the tongue in 11 cases (29.7%) and gingiva with 5 cases (13.5%). The average size of the lesions was 4.25 mm in diameter, with a mean evolution time of 5.9 months. The recurrence rate was slightly higher with the CO2 laser (14.3 %) in comparison with the conventional scalpel (10%). No recurrences for Er,Cr:YSGG were found. CONCLUSIONS: No differences for recurrence rates for OSCP between groups were found. The recurrence rate is low, happening usually before 15 months of follow-up. OSCPs are lesions usually appearing in patients between 30 and 50 years of both genders and located predominantly on the palate, tongue and gingiva.

Comparative study of upper lip frenectomy with the CO2 laser versus the Er, Cr:YSGG laser.

OBJECTIVES: To compare upper lip frenulum reinsertion, bleeding, surgical time and surgical wound healing in frenectomies performed with the CO2 laser versus the Er, Cr:YSGG laser. STUDY DESIGN: A prospective study was carried out on 50 randomized pediatric patients who underwent rhomboidal resection of the upper lip frenulum with either the CO2 laser or the Er,Cr:YSGG laser. Twenty-five patients were assigned to each laser system. All patients were examined at 7, 14, 21 days and 4 months after the operation in order to assess the surgical wound healing. RESULTS: Insertion of the frenulum, which was preoperatively located between the upper central incisors, migrated to the mucogingival junction as a result of using both laser systems in all patients. Only two patients required a single dose of 650 mg of paracetamol, one of either study group. CO2 laser registered improved intraoperative bleeding control results and shorter surgical times. On the other hand, the Er,Cr:YSGG laser achieved faster healing. CONCLUSIONS: Upper lip laser frenectomy is a simple technique that results in minimum or no postoperative swelling or pain, and which involves upper lip frenulum reinsertion at the mucogingival junction. The CO2 laser offers a bloodless field and shorter surgical times compared with the Er,Cr:YSGG laser. On the other hand, the Er,Cr:YSGG laser achieved faster wound healing.

In vitro evaluation of the temperature increment at the external root surface after Er,Cr:YSGG laser irradiation of the root canal.

OBJECTIVES: A study was made to determine the temperature increment at the dental root surface following Er,Cr:YSGG laser irradiation of the root canal. DESIGN: Human canines and incisors previously instrumented to K file number ISO 30 were used. Irradiation was carried out with glass fiber endodontic tips measuring 200 mm in diameter and especially designed for insertion in the root canal. The teeth were irradiated at 1 and 2 W for 30 seconds, without water spraying or air, and applying a continuous circular movement (approximately 2 mm/sec.) in the apico-coronal direction. RESULTS: At the 1 W power setting, the mean temperature increment was 3.84 degrees C versus 5.01 degrees C at 2 W. In all cases the difference in mean value obtained after irradiation versus the mean baseline temperature proved statistically significant (p<0.05). CONCLUSIONS: Application of the Er,Cr:YSGG laser gives rise to a statistically significant temperature increment at the external root surface, though this increment is probably clinically irrelevant, since it would appear to damage the tissues (periodontal ligament and alveolar bone) in proximity to the treated tooth.

ArF excimer laser irradiation of human dentin.

BACKGROUND AND OBJECTIVE: The use of excimer lasers for treatment of dental hard tissues has considerable potential because the combined characteristics of low wavelength and short pulse result in limited heat diffusion and, therefore, tissue ablation without the problems of collateral damage. To date, there are relatively few published studies concerning the effects of excimer laser irradiation on dental hard tissues. Thus the present study was conducted to examine the morphological changes in tooth dentin subsequent to ArF excimer laser irradiation. STUDY DESIGN/MATERIALS AND METHODS: The morphologic changes induced in normal, nondiseased human dentin following irradiation by an ArF excimer laser at fluences ranging from 1 to 4 J/cm2 and the number of laser pulses ranging from 50 to 1,000 were evaluated by scanning electron microscopy. RESULTS: Two modes of ablation, photochemical at low fluences and thermal at high fluences, were observed. A fluence of 1 J/ cm2 when combined with 50 or 100 pulses produced a uniform ablation of the dentin surface without signs of tissue melting. At fluences > 1.5 J/cm2, the thermal mode of ablation was more efficient at removing intertubular dentin than peritubular dentin. Further, when compared to the lower fluences, the higher settings produced a rougher ablation crater surface. Additionally, the higher fluences produced surface melting with each pulse and sealing of exposed dentinal tubules after irradiation with 100-300 laser pulses. CONCLUSIONS: The photochemical and thermal mechanisms of tooth dentin ablation were identified based on significant differences in tissue morphology following laser irradiation. The rates of tissue ablation and the observed morphologic changes indicate that the ArF excimer laser could be useful for caries removal and sealing of exposed dentinal tubules.