Comparative effects of wavelengths of low-power laser in regeneration of sciatic nerve in rats following crushing lesion

Peripheral nerves are structures that, when damaged, can result in significant motor and sensory disabilities. Several studies have used therapeutic resources with the aim of promoting early nerve regeneration, such as the use of low-power laser. However, this laser therapy does not represent a consensus regarding the methodology, thus yielding controversial conclusions. The objective of our study was to investigate, by functional evaluation, the comparative effects of low-power laser (660 nm and 830 nm) on sciatic nerve regeneration following crushing injuries. Twenty-seven Wistar rats subjected to sciatic nerve injury were divided into three groups: group sham, consisting of rats undergoing simulated irradiation; a group consisting of rats subjected to gallium-aluminum-arsenide (GaAlAs) laser at 660 nm (10 J/cm(2), 30 mW and 0.06 cm(2) beam), and another one consisting of rats subjected to GaAlAs laser at 830 nm (10 J/cm(2), 30 mW and 0.116 cm(2)). Laser was applied to the lesion for 21 days. A sciatic functional index (SFI) was used for functional evaluation prior to surgery and on days 7, 14, and 21 after surgery. Differences in SFI were found between group 660 nm and the other ones at the 14th day. One can observe that laser application at 660 nm with the parameters and methods utilised was effective in promoting early functional recovery, as indicated by the SFI, over the period evaluated.

Does Trochanteric Transfer Eliminate the Trendelenburg Sign in Adults?

Premature closure of the proximal femoral growth plate results in coxa brevis, which usually is associated with insufficiency of the hip abductors. Distal and lateral transfer of the greater trochanter sometimes is recommended to correct this problem. Most of what is known arises from studies of children and adolescents. We asked whether this procedure in adults with coxa brevis would eliminate hip abductor insufficiency and would improve their hip function based on the Harris hip score (HHS). We prospectively followed 11 patients, aged 19 to 55 years (mean, 40 years) who had distal and lateral trochanteric transfer. All patients had pain and a positive Trendelenburg test before surgery. This test was performed at the latest followup by three observers and the interobserver reliability was determined by the kappa coefficient. The HHS was obtained before surgery and at the latest followup. The minimum followup was 25 months (mean, 52 months; range, 25-77 months). Insufficiency of the hip abductors was eliminated in seven (according to two observers) and eight (according to one observer) of the 11 patients after surgery; the kappa coefficient ranged from 0.79 to 1.0. The mean HHS improved from 64 points preoperatively to 76 points at the final followup. The two patients with preexisting severe osteoarthritis of the hip had the worst final scores and persisted with a positive Trendelenburg test at the final followup. Distal and lateral transfer of the greater trochanter can eliminate insufficiency of the hip abductors and improve joint function in adult patients with coxa brevis and we believe should be considered for patients without severe osteoarthritis of the hip. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Masticatory muscle function three years after surgical correction of class III dentofacial deformity

Individuals with dentofacial deformities have masticatory muscle changes. The objective of the present study was to determine the effect of interdisciplinary treatment in patients with dentofacial deformities regarding electromyographic activity (EMG) of masticatory muscles three years after surgical correction. Thirteen patients with class III dentofacial deformities were studied, considered as group PI (before surgery) and group P3 (3 years to 3 years and 8 months after surgery). Fifteen individuals with no changes in facial morphology or dental occlusion were studied as controls. The participants underwent EMG examination of the temporal and masseter muscles during mastication and biting. Evaluation of the amplitude interval of EMG activity revealed a difference between P1 and P3 and no difference between P3 and the control group. In contrast, evaluation of root mean square revealed that, in general, P3 values were higher only when compared with PI and differed from the control group. There was an improvement in the EMG activity of the masticatory muscles, mainly observed in the masseter muscle, with values close to those of the control group in one of the analyses.

Masseter muscle thickness three years after surgical correction of class III dentofacial deformity

Objective: To analyse the effect of integrated orthodontic treatment, orthognathic surgery and orofacial myofunctional therapy on masseter muscle thickness in patients with class III dentofacial deformity three years after orthognathic surgery. Design: A longitudinal study was conducted on 13 patients with class III dentofacial deformities, denoted here as group P1 (before surgery) and group P3 (same patients 3 years to 3 years and 8 months after surgery). Fifteen individuals with no changes in facial morphology or dental occlusion were assigned to the control group (CG). Masseter muscle ultrasonography was performed in the resting and biting situations in the three groups. Data were analysed statistically by a mixed-effects linear model considering a level of significance of P < 0.05. Results: Significantly higher values (P < 0.01) of masseter muscle thickness (cm) were detected in group P3 (right rest: 0.82 +/- 0.16, left rest: 0.87 +/- 0.21, right bite: 1 +/- 0.22, left bite: 1.04 +/- 0.28) compared to group P1 (right rest: 0.63 +/- 0.19, left rest: 0.64 +/- 0.15, right bite: 0.87 +/- 0.16, left bite: 0.88 +/- 0.14). Between P3 and CG (right rest: 1.02 +/- 0.19, left rest: 1 +/- 0.19, right bite: 1.18 +/- 0.22, left bite: 1.16 +/- 0.22) there was a significant difference on the right side of the muscle (P < 0.05) in both situations and on the left side at rest. Conclusion: The proposed treatment resulted in improved masseter muscle thickness in patients with class III dentofacial deformity. (C) 2011 Elsevier Ltd. All rights reserved.

Changes in facial morphology after adenotonsillectomy in mouth-breathing children

Background. Morphological and dentofacial alterations have been attributed to impaired respiratory function. Objective. To examine the influence of mouth breathing (MB) on children facial morphology before and after adenoidectomy or adenotonsillectomy. Methods. Thirty-three MB children who restored nasal breathing (NB) after surgery and 22 NB children were evaluated. Both groups were submitted to lateral cephalometry, at time 1 (T1) before and at time 2 (T2) 28 months on average postoperatively. Results. Comparison between the MB and NB groups at T1 showed that mouth breathers had higher inclination of the mandibular plane; more obtuse gonial angle; dolichofacial morphology; and a decrease in the total and inferior posterior facial heights. Twenty-eight months after the MB surgical intervention, they still presented a dolichofacial morphologic pattern. During this period, MB altered the face growth direction and decreased their mandible plane inclination, with reduction in the SN.GoGn, PP.MP, SNGn, and ArGo.GoMe parameters as well as an increase in BaN.PtGn. Conclusion. After the MB rehabilitation, children between 3 and 6 years old presented significant normalization in the mandibular growth direction, a decrease in the mandible inclination, and an increase in the posterior facial height. Instead, they still persisted with a dolichofacial pattern when compared with nasal breathers.

Hydrocephalus in posterior fossa tumors in children. Are there factors that determine a need for permanent cerebrospinal fluid diversion?

We searched for factors that could predispose towards persistent hydrocephalus in children with posterior fossa (PF) tumors in order to determine the need for permanent cerebrospinal fluid (CSF) diversion. The clinical records of 64 children who underwent surgery for PF tumors in the Pediatric Neurosurgery division of the Hospital of Clinics, Ribeirao Preto, Brazil, from 1990 to 2006, were retrospectively reviewed. The patients` ages ranged from 3 months to 18 years. The factors evaluated included age at surgery, severity of hydrocephalus (ventricular index), tumor location, size of the tumor, extent of tumor resection, and histology. Ventricular index, measured from the initial neuroradiological image, age at surgery, and location of the tumor were significantly associated with definitive postoperative CSF diversion (shunt or endoscopic third ventriculostomy), which was necessary for 34% of the patients. Young children with severe preoperative hydrocephalus and a midline tumor should be considered at risk when preoperative treatment decisions are made.

The Impact of Preexisting Myocardial Remodeling on Ventricular Function Early after Tetralogy of Fallot Repair

Background: Twenty-three patients (median age 23 months) who underwent Fallot`s tetralogy repair were investigated prospectively to detect a possible association between histopathologic myocardial remodeling and echocardiographic findings of systolic or diastolic ventricular dysfunction. Methods: Intraoperatively resected infundibular bands and subendocardial biopsy samples from the right ventricle (RV) and left ventricle were obtained for histopathologic evaluation. Tissue Doppler echocardiographic interrogation of the ventricles was performed before surgery and in the postoperative period. Results: Histopathologic data revealed hypertrophy of the RV cardiomyocytes and increased interstitial collagen in both ventricles. Mean values of RV isovolumic acceleration decreased significantly at the third evaluation compared with the preoperative values (P = .006). RV myocardial fibrosis greater than 8.3% was associated with a probability of altered E` of at least 0.7 (odds ratio = 2.31). Conclusion: Preoperative histologic myocardial remodeling influenced the postoperative RV function in this group of patients with late repair. Further studies are necessary to evaluate the myocardium in younger patients and to define its influence in the long-term follow-up. (J Am Soc Echocardiogr 2010;23:912-8.)

Localization of the Mandibular Canal in Brachycephalic Dogs Using Computed Tomography

For some surgical procedures in veterinary dentistry including exodontia, orthognathic surgery, orthopedic surgery, oncologic surgery, and for the placement of dental implants, it is important to know the accurate location of the neurovascular structures within the mandibular canal. The aim of this research was to determine the course of the mandibular canal in the mandible and its relationship with other anatomical structures in brachycephalic dogs using computerized tomography. Mandibles from 10 brachycephalic cadaver dogs were evaluated. Measurements were taken in relation to the lingual, vestibular alveolar crest, and ventral surfaces. These measurements indicated that the mandibular canal descends slightly from the mandibular foramen to the molar area, decreasing the distance of the mandibular canal from the mandibular ventral border The mandibular canal is slightly closer to the lingual surface than the vestibular surface except in the molar tooth region. The mandibular canal continues in a rostral direction occupying the ventral region of the mandibular body, reaching its maximum distance from the alveolar crest at the level of the first molar and fourth premolar teeth. In the third and fourth premolar tooth region, the mandibular canal maintains a similar distance between the vestibular and lingual borders; then, at the level of the second premolar tooth, the distance of the mandibular canal from the lingual and ventral border increases before its termination at the mental, foramen. The study reported here documents the feasibility of using CT to determine the location of the mandibular canal in relation to bony and dental parameters. Although the difference in mandible size of the group of brachycephalic dogs reported here resulted in broad ranges of measurements, it is clear that the MC course may vary between individual dogs. J Vet Dent 26(3); 156 - 163, 2009

Stem cell proliferation under low intensity laser irradiation: A preliminary study

Background and Objectives: Phototherapy with low intensity laser irradiation has shown to be effective in promoting the proliferation of different cells. The aim of this in vitro study was to evaluate the potential effect of laser phototherapy (660 nm) on human dental pulp stem cell (hDPSC) proliferation. Study Design/Materials and Methods: The hDPSC cell strain was used. Cells cultured under nutritional deficit (10% FBS) were either irradiated or not (control) using two different power settings (20 mW/6 seconds to 40 mW/3 seconds), with an InGaAIP diode laser. The cell growth was indirectly assessed by measuring the cell mitochondrial activity through the MTT reduction-based cytotoxicity assay. Results: The group irradiated with the 20 mW setting presented significantly higher MTT activity at 72 hours than the other two groups (negative control-10% FBSand lased 40 mW with 3 seconds exposure time). After 24 hours of the first irradiation, cultures grown under nutritional deficit (10% FBS) and irradiated presented significantly higher viable cells than the non-irradiated cultures grown under the same nutritional conditions. Conclusions: Under the conditions of this study it was possible to conclude that the cell strain hDPSC responds positively to laser phototherapy by improving the cell growth when cultured under nutritional deficit conditions. Thus, the association of laser phototherapy and hDPSC cells could be of importance for future tissue engineering and regenerative medicine. Moreover, it opens the possibility of using laser phototherapy for improving the cell growth of other types of stem cells.

Use of laser phototherapy on a delayed wound healing of oral mucosa previously submitted to radiotherapy: case report

Radiotherapy produces both acute and delayed effects on mucosal tissues, disturbing their healing. This report shows a successful treatment with laser phototherapy (LPT) on a delayed wound healing in oral mucosa previously submitted to radiotherapy with a follow up of 3 years. A 47-year-old patient treated 6 months earlier for tongue squamous cell carcinoma by surgery and radiotherapy presented with a mass in the operated area. Biopsy showed chronic inflammatory infiltrate around a residual polyglactin suture. After 2 months there was a painful mucosal dehiscence on the biopsy site. LPT was performed using a semiconductor laser with 660-nm wavelength (InGaAlP) and spot size of 0.04 cm(2). The parameters applied were 40 mW, 4 Jcm(2)/point, 0.16 J/point, 2.4 J/session. The irradiation was performed punctually, through contact mode in 15 points (4 seconds/point), on top of and around the lesion, during ten sessions. The wound healed completely after ten sessions. This treatment proved to be conservative and effective, inducing healing of a chronic wound in a tissue previously submitted to radiotherapy.

Prognostic impact of adenomatous polyposis coil gene expression in osteosarcoma of the extremities

Purpose: To evaluate the impact of adjuvant chemotherapy on the outcome of osteosarcoma of the extremities, and to identify prognostic factors using the expression of adenomatous polyposis coli (APC), cadherin and beta-catenin Wnt-signalling markers. Methods: The clinical, demographic, anatomic and pathological factors including a detailed analysis of the immunohistochemical expression of cadherin, B-catenin and APC were retrospectively examined in 97 patients with osteosarcoma of the extremities (metastatic and non-metastatic at diagnosis), treated with surgery and/or chemotherapy from 1985 to 2000. Results: APC immunoreactivity showed a statistically significant association with age and serum alkaline phosphatase levels (p = 0.025 and p = 0.038). When survival was the end-point of multivariate analysis, race segregated patients with poor survival as did lack of cadherin expression. For overall survival, cadherin immunoreactivity and the interaction between APC expression and response to adjuvant chemotherapy were significant (p = 0.012 and p < 0.001). No significant clinical association was evident with immunohistochemical expression of cadherin, beta-catenin. Conclusion: Lack of expression of cadherin was a significant variable to overall and disease-free survival. Significantly, positive APC immunoreactivity and adjuvant chemotherapy were associated with a favourable treatment response. Studies using newer immunohistochemical markers within the Wnt-signalling pathway may guide the development of more appropriate therapeutic targets for future individualised treatment. (C) 2010 Elsevier Ltd. All rights reserved.

Influence of Cavity Preparation with Er:YAG Laser on Enamel Adjacent to Restorations Submitted to Cariogenic Challenge In Situ: A Polarized Light Microscopic Analysis

Background and Objectives: Er:YAG laser has been used for caries removal and cavity preparation, using ablative parameters. Its effect on the margins of restorations submitted to cariogenic challenge has not yet been sufficiently investigated. The aim of this study was to assess the enamel adjacent to restored Er:YAG laser-prepared cavities submitted to cariogenic challenge in situ, under polarized light microscopy. Study Design/Materials and Methods: Ninety-one enamel slabs were randomly assigned to seven groups (n = 13): I, II, III-Er:YAG laser with 250 mJ, 62.5 J/cm(2), combined with 2, 3, and 4 Hz, respectively; IV, V, VI-Er:YAG laser with 350 mJ, 87.5 J/cm(2), combined with 2, 3, and 4 Hz, respectively; VII-High-speed handpiece (control). Cavities were restored and the restorations were polished. The slabs were fixed to intra-oral appliances, worn by 13 volunteers for 14 days. Sucrose solution was applied to each slab six times per day. Samples were removed, cleaned, sectioned and ground to polarized light microscopic analysis. Demineralized area and inhibition zone width were quantitatively assessed. Presence or absence of cracks was also analyzed. Scores for demineralization and inhibition zone were determined. Results: No difference was found among the groups with regard to demineralized area, inhibition zone width, presence or absence of cracks, and demineralization score. Inhibition zone score showed difference among the groups. There was a correlation between the quantitative measures and the scores. Conclusion: Er:YAG laser was similar to high-speed handpiece, with regard to alterations in enamel adjacent to restorations submitted to cariogenic challenge in situ. The inhibition zone score might suggest less demineralization at the restoration margin of the irradiated substrates. Correlation between the quantitative measures and scores indicates that score was, in this case, a suitable complementary method for assessment of caries lesion around restorations, under polarized light microscopy. Lasers Surg. Med. 40:634-643, 2008. (c) 2008 Wiley-Liss, Inc.

Healing of critical-size cranial defects in guinea pigs using a bovine bone-derived resorbable membrane

Purpose: To investigate the healing of critical-size cranial bone defects (9-mm-diameter) in guinea pigs treated with a bovine bone-derived resorbable membrane. Materials and Methods: A sample of 42 guinea pigs was divided into test (n = 20), control (n = 20), and standard (n = 2) groups. A full-thickness trephine defect was made in the fronto-parietal bone of each animal. In the test group, the internal and external openings of the defect were each closed with a separate membrane, and the space between them was filled with blood clot and a central spacer. In the control group, the defect was filled only with the blood clot and spacer. At 1, 3, 6, and 9 months later, the calvarias (5 per period) for both the test and control groups were collected, fixed, radiographed, and histologically processed. The Standard-group animals were sacrificed immediately after surgery and used to determine the initial size of defect radiographically. The areas of defects in the radiographs were measured with image-analysis software and were compared between groups and periods by multiple regression analysis with the Bonferroni correction. Results: At 1 and 3 months, newly formed woven bone was histologically observed in both test and control groups. Radiographically, this new bone occupied an average of 32% of the defect area at 1 month and 60% at 3 months in the test group. In the control group, 21% of the defect was filled at 1 month and 39% at 3 months. However, the differences between treatments were not statistically significant (P > .05). At 6 and 9 months, a significant increase in newly formed lamellar bone was seen histologically in both groups. Radiographically, for the test group, the new bone occupied an average of 82% of the defect area at 6 months and 96% at 9 months. For the control group, new bone composed an average of 45% of the defect area at 6 months and 40% at 9 months. The differences between the test and control groups were statistically significant at 6 and 9 months (P < .05). Complete or almost complete filling of the defect was observed in several cases. Conclusion: It was concluded that the bovine bone-derived membrane is highly biocompatible and is able to promote good healing of critical-size defects in calvaria of guinea pig.

Biocompatibility evaluation of alendronate paste in rat`s subcutaneous tissue

Alendronate is a known inhibitor of root resorption and the development of alendronate paste would enhance its utilization as intracanal medication. Therefore, this study aimed to investigate the biocompatibility of experimental alendronate paste in subcutaneous tissue of rats, for utilization in teeth susceptible to root resorption. The study was conducted on 15 male rats, weighing similar to 180-200 grams. The rats` dorsal regions were submitted to one incision on the median region and, laterally to the incision, the subcutaneous tissue was raised and gently dissected for introduction of two tubes, in each rat. The tubes were sealed at one end with gutta-percha and taken as control. The tubes were filled with experimental alendronate paste. The animals were killed at 7, 15 and 45 days after surgery and the specimens were processed in laboratory. The histological sections were stained with hematoxylin-eosin and analyzed by light microscopy. Scores were assigned to the in. ammatory process and statistically compared by the Tukey test (P < 0.05). Alendronate paste promoted severe inflammation process at 7 days, with statistically significant difference compared to the control (P < 0.05%). However, at 15 days, there was a regression of in. ammation and the presence of connective tissue with collagen fibers, fibroblasts and blood vessels was observed. After 45 days, it was observed the presence of well-organized connective tissue, with collagen fibers and fibroblasts, and few in. ammatory cells. No statistical difference was observed between the control and experimental paste at 15 and 45 days. The experimental alendronate paste was considered biocompatible with subcutaneous tissue of rat.

Comparison of oral versus sublingual piroxicam during postoperative pain management after lower third molar extraction

In this study, 53 patients received piroxicam, administered orally or sublingually, after undergoing removal of symmetrically positioned lower third molars, during two separate appointments. This study used a randomized, blind, cross-over protocol. Objective and subjective parameters were recorded for comparison of postoperative results for 7 days after surgery. Patients treated with oral or sublingual piroxicam reported low postoperative pain scores. The patients who received piroxicam orally took a similar average amount of analgesic rescue medication compared with patients who received piroxicam sublingually (p > 0.05). Patients exhibited similar values for mouth opening measured just before surgery and immediately following suture removal 7 days later (p > 0.05), and showed no significant differences between routes of piroxicam administration for swelling control during the second or seventh postoperative days (p > 0.05). In summary, pain, trismus and swelling after lower third molar extraction, independent of surgical difficulty, could be controlled by piroxicam 20 mg administered orally or sublingually and no significant differences were observed between the route of delivery used in this study.