Drug use, risk perceptions and attitudes towards drug use amongst medical and dentistry students.

AIMS: To analyse the use of psychoactive substances and the risk perceptions amongst odontology and medical students. To study their perceptions, attitudes and knowledge, and to evaluate their motivation when helping their patients to stop using these substances. METHODS: A cross-sectional study was conducted amongst 962 students in Spain, using validated questionnaires on an anonymous basis. RESULTS: Amongst these students, drug use varies and increases with age as assessed by the DAST and CAST tests, with more problematic use being observed as the academic cycle progresses (p < .001). Participants in the 2nd cycle presented higher consumption than those in the 1st cycle, in the univariate model (OR = 1.77, IC 95% 1.27-2.48, p = .001) and in the adjusted model (OR = 1.86, IC 95% 1.32-2.62, p < .001). Regarding CAST, non-problematic use in the 1st cycle versus the 3rd cycle presented an OR = 8.69 (IC 95% 4.50-16.78, p < .001) and for low risk use it presented an OR = 15.18 (IC 95% 1.83-14.68). Only 46.7% considered using marijuana on a regular basis as a high risk, whilst 60.5% stated that smoking a pack of cigarettes represents a high risk. Alcohol was the substance for which the risk perception was lowest. 66.2% are in the maintenance stage "I provide my regular drug-using patients help to give up," with women being more likely to be in this stage (p = .012). CONCLUSIONS: High risk of drug use increases after the 1st cycle in Dentistry and in Medicine. Training programmes should be implemented in both degrees, focusing on the 1st years in order to simultaneously prevent drug use amongst students.

Exosomes in head and neck cancer. Updating and revisiting.

Exosomes have gone from being considered simple containers of intracellular waste substances to be considered important carriers of cellular signals. Its broad capacity to promote tumour growth, both in situ and metastatic, has greatly intensified scientific research on them. In the same way and depending on its content, its tumour suppressive properties have opened a window of light and hope in the fight against cancer. In the present review we try to gather in a simple and understandable way the most relevant knowledge to date on the role of exosomes in oral squamous cell carcinoma, helping to understand their process of formation, release and activity on the tumour microenvironment.

Evaluation of a new tricalcium phosphate for guided bone regeneration: an experimental study in the beagle dog.

This study compared the in vivo behavior of two biomaterials, xenograft (Bio-Oss®) and alloplastic tricalcium phosphate (Sil-Oss®), vs a control (no biomaterial) in beagle dogs treated with guided bone regeneration (GBR). Six male adult beagle dogs were included. The third and fourth mandibular premolars and first mandibular molars (3P3, 4P4 and 1M1) on both sides were extracted. After 12 weeks of healing, Straumann implants (3.3 × 8 mm) were placed, performing standardized defects (3.3 × 6 mm) in the vestibular aspect of the alveolar bone. The defects were surgically treated by randomized placement of xenograft (Bio-Oss®), alloplastic tricalcium phosphate (Sil-Oss®) or no biomaterial and covered with a resorbable collagen membrane (BioGide®). After an additional 12-week healing period, the lower jaws were dissected. Total area regenerated in the region of interest, total volume, bone to implant contact in the regenerated area, and volumetric changes were measured through histological, histomorphometrical and microcomputed tomography (microCT) techniques. The negative control group showed bone ingrowth inside the defect, with a partial collapse of the buccal bone. This was not observed in the biomaterial-treated groups. Defects treated with the xenograft showed 51.40% (SD 19.83) newly mineralized tissue, while those treated with alloplastic tricalcium showed 62.54% (SD 11.54) newly mineralized tissue; the control showed 71.52% (SD 6.46). Alloplastic tricalcium phosphate modified with monetite and zinc showed similar features in alveolar regeneration of defects to those treated with the xenograft or conventional GBR, but it showed an ideally higher rate of new mineralized tissue formation and accelerated resorption.

Surgical neurolysis for the treatment of neuropathic pain in 2 postmenopausal women with mandibular necrosis resulting from oral bisphosphonates.

We analyze the use of surgical neurolysis for the treatment of neuropathic pain of the inferior alveolar nerve. For that, 3 surgical neurolysis were performed on 2 postmenopausal women experiencing neuropathic pain of the inferior alveolar nerve due to mandibular necrosis resulting from treatment with oral bisphosphonates. Both patients showed sensory impairment of the inferior alveolar nerve. We obtained complete control of neuropathic pain after 6 months of the patients' evolution, preserving the function of the lingual nerve in all 3 neurolysis, without causing any impact as regards to the sensitive situation before treatment. Surgical neurolysis of the inferior alveolar nerve may be considered as the choice therapeutic technique to treat neuropathic pain of this nerve when there is a sensory impairment in patients showing mandibular necrosis resulting from bisphosphonates.

Clinical study comparing alveolar distraction using the lead system and MODUS MDO 1.5/2.0.

This article compares 2 different alveolar distractors: Lead System (LS) and MODUS MDO 1.5/2.0 (M-MDO). This is a clinical retrospective study; 32 distractions were performed. We used the LS distractor (intraosseous) on 24 patients and the M-MDO (extraosseous) on the other 8. The variables included bone alveolar ridge height, alterations of the oral mucosa, number of distractors, implant survival, and complications. We also developed descriptive and univariate statistical analysis. The mean increase of bone height after performing the alveolar distraction was 6.15 mm, 5.74 mm with LS, and 8.36 mm with M-MDO (P < 0.0001). The survival rates of the implants in the intraosseous and extraosseous groups reached 100%. However, the use of M-MDO resulted in a significant defect in the alveolar mucosa during implant insertion (100%), an event that did not occur when using LS (P < 0.001). The most common complication in the intraosseous group was the tilting of the segment (25%), whereas, in the extraosseous group, the main difficulty was the rod interference with the opposing arch (75%). Bone defects after alveolar distraction appeared both in the intraosseous group (66.7%) and in the extraosseous group (50%). Both the LS and the M-MDO distractors are effective for alveolar bone distraction. The choice of one distractor over another depends on the clinical characteristics of each case, such as the size and shape of the defect, the patient's tolerance, the distance to the opposing arch, and the surgeon's experience.

Blood loss in orthognathic surgery: a systematic review.

PURPOSE: Intraoperative blood loss during orthognathic surgery is frequently abundant and sometimes requires blood transfusion. The aim of the present study was to conduct a systematic review of the published data regarding intraoperative blood loss during orthognathic surgical interventions, including Le Fort I osteotomy, mandibular ramus osteotomy, and both combined, to determine the range of information available to help surgeons better prepare themselves, their patients, and the auxiliary support needed for this type of surgery and the transfusion requirements. MATERIALS AND METHODS: Selected reports from the PubMed and Cochrane Library databases for studies conducted from 1978 to 2008 were evaluated to determine whether they included information on the volume of bleeding during surgery and the factors that might have influenced the amount of bleeding. Of the 90 reports examined and evaluated, 7 were included in the critical analysis conducted as a part of the present systematic review. RESULTS: Referring to the reports used for statistical analysis of the volume of blood loss, the mean intraoperative bleeding volume was 436.11 mL, the mean of the standard deviations was ±207.89 mL, and mean surgery duration was 196.9 minutes. CONCLUSIONS: Our results have shown that the intraoperative bleeding observed in patients during Le Fort I or mandibular ramus osteotomies or both combined was less than the limits set for blood transfusion. However, bleeding was occasionally heavier, and surgeons should be prepared for heavier bleeding by reserving blood at a blood bank or by preparing an autotransfusion.

Intracellular pH regulation in oral squamous cell carcinoma is mediated by increased V-ATPase activity via over-expression of the ATP6V1C1 gene.

Oral squamous cell carcinomas represent more than 90% of all head and neck cancers, and comprise about 4% of all malignancies in western countries. Tumor cell mobility related to increasing intracellular pH results in impaired proliferation and metastasis, suggesting an important role of pH regulation in solid cancer tumorigenesis. The mechanism of physiological pH regulation has been shown to be activated in several solid tumors through constitutive activation of the ATPase complex. How cells regulate this mechanism has not been elucidated in human cancer in detail. The present study, using expression profiling by cDNA array analysis of oral squamous cell carcinoma cells, identified the V-ATPase system as a significant regulatory mechanism. ATP6V1C1 was the most strongly over-expressed gene in oral squamous cell carcinoma at the mRNA level compared to other genes of the V-ATPase complex. These findings provide evidence that intracellular pH regulation is mainly controlled by expression of a single gene, ATP6V1C1, notwithstanding the possible action of other secondary regulatory factors.

Piezoelectric and conventional osteotomy in alveolar distraction osteogenesis in a series of 17 patients.

UNLABELLED: Piezoelectric osteotomy is based on ultrasonic vibration of an osteotomic device that permits precise cutting of bone structures without cutting adjacent soft tissues. To date, however, there have been no studies of the outcome and complications of alveolar distraction for piezoelectric osteotomy versus conventional osteotomy. The present study evaluated piezoelectric versus conventional osteotomy in alveolar distraction. MATERIALS AND METHODS: A retrospective study was performed on all patients of the authors who requested dental implants and who after preliminary evaluation were judged to require alveolar distraction osteogenesis for rehabilitation of edentulous mandibular regions. The distraction was performed using the same distraction system in all cases, but with the osteotomy performed either by conventional techniques using rotary instruments and chisels (conventional osteotomy group, n = 11), or by piezoelectric osteotomy using the Piezosurgery system (Mectron Medical Technology; Carasco, Genoa, Italy; n = 6). The 17 distractions were compared with respect to patient age, patient sex, intra- and postoperative complications, degree of surgical difficulty, postdistraction morphology of the alveolar ridge, and rehabilitation success rate. RESULTS: Both surgical difficulty (as measured by the number of surgical instruments required) and the incidence of intraoperative complications were significantly lower in the piezoelectric osteotomy group than in the conventional osteotomy group. However, postdistraction morphology of the alveolar ridge (as determined at implant placement) was worse in the piezoelectric osteotomy group than in the conventional osteotomy group (P = .072). The overall rehabilitation success rate was 100% in the conventional osteotomy group versus only 66.7% (4 of 6 cases) in the piezoelectric osteotomy group. CONCLUSIONS: The use of piezoelectric osteotomy in alveolar distraction appears to simplify surgery and reduce the incidence of intraoperative complications. However, results also suggest that piezoelectric osteotomy increases the risk of postoperative and postdistraction complications and reduces the overall rehabilitation success rate.

Peri-implant bone resorption around implants placed in alveolar bone subjected to distraction osteogenesis.

PURPOSE: This study was conducted to evaluate bone resorption around implants placed in alveolar bone previously subjected to distraction osteogenesis (DO). PATIENTS AND METHODS: The study included 9 patients who had undergone alveolar DO with subsequent placement of 37 implants. None of the implants was lost. Vertical peri-implant bone deficit was measured on the distal and mesial surfaces from panoramic radiographs obtained at implant loading and again 1 year later. Resorption over the year of loading was calculated as the increase in vertical bone deficit. RESULTS: Mean peri-implant bone resorption over the first year after loading was 0.60 mm mesially and 0.68 mm distally. In both cases, the resorption (ie, the difference between the mean bone deficit at loading and 1 year later) was statistically significant (P < .05). CONCLUSION: Vertical bone resorption around implants placed in distracted alveolar bone is similar to that seen around implants placed in nondistracted bone.

Piezoelectric bone surgery applied in alveolar distraction osteogenesis: a technical note.

Piezoelectric bone surgery is based on ultrasonic vibration of a device functioning as an osteotome. This device allows precise cuts to be made in bone structures without provoking lesions of adjacent soft tissues and at the same time offering excellent visibility within the surgical field. The use of this technique in alveolar distraction osteogenesis is described. Piezoelectric surgery appears to make the cutting of the transport segment easier and safer.

Ultrasonic osteotomy in oral surgery and implantology.

Over the past decade, coinciding with the appearance of a number of new ultrasonic surgical devices, there has been a marked increase in interest in the use of ultrasound in oral surgery and implantology. This paper reviews the published literature on ultrasonic osteotomy in this context, summarizes its advantages and disadvantages, and suggests when it may and may not be the technique of choice.

Modified LEAD System distractor to prevent tilting during alveolar distraction in the mandibular symphyseal region.

This report describes a simple modification of the LEAD System distractor that prevents tilting of the distractor rod, and consequent deviation of distraction direction, during alveolar distraction in the mandibular symphysis region.

Relapse in alveolar distraction osteogenesis: an indication for overcorrection.

PURPOSE: The aim of this study was to indicate the necessity of overcorrection regarding the occurrence of bone height relapse at the end of consolidation period in distracted alveolar bone. MATERIALS AND METHODS: Eleven patients with a total of 17 distractions performed and 43 implants placed were included in this study. Bone height was evaluated on computed tomography before the procedure and on orthopantomographic radiographs following distraction and consolidation. Measurement was performed on the aproximal surfaces of implants and on identical points before and after distraction. RESULTS: The mean of distraction performed was 6.08 +/- 1.82 mm at mesial points and 6.18 +/- 1.90 mm at distal points of measurement. The mean of bone relapse following consolidation period was 1.57 +/- 1.82 mm at the mesial and 1.79 +/- 1.68 mm at the distal aspects of implants. Statistical evaluation revealed that alveolar bone distraction should include 20% of overcorrection for both mesial and distal points of measurements plus 0.34 mm for mesial and 0.52 mm for distal points of measurement. CONCLUSIONS: Occurrence of relapse found in this study indicates that overcorrection should be included when performing alveolar distraction osteogenesis.

Distraction osteogenesis of the alveolar ridge: a review of the literature.

One of the principal problems in dental implantation is the lack of sufficient bone height or width. In the case of the alveolar ridge, a very effective technique for resolving this problem is distraction osteogenesis, introduced in this context about a decade ago. This technique is based on the gradual separation of a mobile but fully vascularized bone segment from the basal bone, leading to the formation of an intervening soft callus which gradually transforms to mature bone. A key researcher in the development of this technique was the Russian traumatologist Ilizarov. The present article reviews alveolar ridge distraction procedures and their clinical application. Alveolar ridge distraction may often be preferable to bone grafting or guided bone regeneration for increasing ridge height and width prior to implantation.

Horizontal alveolar distraction: a surgical technique with the transport segment pedicled to the mucoperiosteum.

PURPOSE: The study goal was to describe a surgical technique for performing horizontal alveolar distraction with the aim of increasing the width of alveolar ridges that are too narrow for dental implant placement. MATERIALS AND METHODS: A transport segment is cut from the vestibular side of the ridge, using osteotomes, and maintaining extensive attachment to the mucoperiosteum. The distraction screw is placed through the vestibular mucosa and the transport segment, in vestibular-palatal direction. Distraction is then performed to increase ridge width. RESULTS: We successfully applied this technique in a patient who required 2 dental implants at adjacent sites in the upper jaw but whose alveolar ridge was too narrow for direct implantation. With horizontal distraction, ridge width was successfully increased, allowing placement of the 2 implants (diameter, 3.3 and 4.1 mm). CONCLUSION: This technique shows promise for patients requiring implants in a narrow alveolar ridge. Depending on each patients specific requirements, we suggest that it be taken into account as a possible alternative to existing techniques.

DNA microarrays in oral cancer.

One of the principal aims of modern cancer research is to identify markers allowing individual prediction of prognosis or response to treatment. In this connection, the number of genes thought to be involved in the different stages of different types of oral cancer increases apace. DNA microarrays allow simultaneous evaluation of the expression of hundreds of genes in a single assay. The parallel format of microassay slides is designed to allow rapid comparison of gene expression between two samples, for example tumor cells and healthy cells. This article reviews studies that have aimed to identify genes related to oral cancer, and to classify these genes into groups that are commonly co-expressed. These studies suggest that DNA microarrays are set to become routine tools in the detection, diagnosis, characterization and treatment of oral cancers.

A preliminary morphologic classification of the alveolar ridge after distraction osteogenesis.

PURPOSE: We sought to develop and evaluate a preliminary morphologic classification of the alveolar ridge after distraction osteogenesis. MATERIALS AND METHODS: Twelve patients (7 women and 5 men; mean age, 42.6 years; age range, 30 to 57 years) underwent a total of 17 alveolar ridge distractions before the placement of a total of 44 dental implants. Ridge bone morphology was evaluated and categorized at implant placement, with subsequent evaluation of the frequency and type of complications in each category. RESULTS: Four morphologic categories were identified, as follows. Category I consisted of wide alveolar rim and no bone defects; 7 (41.2%) of the 17 ridges were assigned to this category, and a total of 22 implants were placed with no complications. Category II consisted of wide alveolar rim, lateral bone surface concavity; 4 (24%) of the 17 ridges were assigned to this category, and a total of 8 implants were placed, with fenestration defects being the most frequent complication (2 of 8 implants [25%]). Category III consisted of narrow alveolar rim, lateral bone surface concavity; 5 (29.4%) of the 17 ridges were assigned to this category, and a total of 13 implants were placed, with dehiscence defects being the most frequent complication (4 of 13 implants [31%]). Category IV consisted of distraction transport segment forming a bridge, without bone formed beneath, necessitating guided bone regeneration; 1 (6%) of the 17 ridges was assigned to this category, and following bone regeneration 1 implant was placed, without complications. Subcategory D consisted of lingual deviation of the distraction axis, occurring in any of categories I to IV, and when severe requiring corrective osteotomy to free and reposition the transport segment and neoformed bone; 4 (24%) of the 17 ridges were assigned to this subcategory (ie, to subcategory ID, IID, IIID, or IVD); in 1 case, the deviation was severe, requiring corrective osteotomy; in this case 3 implants were placed, without complications. CONCLUSION: This preliminary morphologic classification of the postdistraction alveolar ridge effectively categorizes the variation observed in our patients and in our experience provides a useful basis for decision-making regarding implant placement. However, further studies are required to confirm the generality of this classification and incidences of complications in each category.