Michele Maglione

Management of dental extraction in patients undergoing anticoagulant treatment. Results from a large, multicentre, prospective, case-control study.

Following favourable results from a previous study, a large, multicentre, prospective, case-control study was performed to further assess the incidence of bleeding complications after dental extraction in patients taking oral anticoagulant therapy (OAT). Four hundred fifty-one patients being treated with warfarin who required dental extraction were compared with a control group of 449 non-anticoagulated subjects undergoing the same procedure. In the warfarin-treated group, the oral anticoagulant regimen was maintained unchanged, such that the patients had an International Normalised Ratio ranging between 1.8 and 4, and local haemostatic measures (i.e. fibrin sponges, silk sutures and gauzes saturated with tranexamic acid) were adopted. All the procedures were performed in an outpatient setting. Seven bleeding complications occurred in the OAT group and four in the control group; the difference in the number of bleeding events between the two groups was not statistically significant (OR=1.754; 95% CI 0.510 - 6.034; p=0.3727). No post-operative late bleeds requiring hospitalisation and/or blood transfusions were recorded, and the adjunctive local haemostatic measures were adequate to stop the bleeding. The results of our protocol applied in this large, multicenter study show that dental extractions can be performed easily and safely in anticoagulated outpatients without any modification of the ongoing anticoagulant therapy, thus minimising costs and reducing discomfort for patients.

Mesenchymal stem cells and inorganic bovine bone mineral in sinus augmentation: comparison with augmentation by autologous bone in adult sheep

Our aim was to compare the osteogenic potential of mononuclear cells harvested from the iliac crest combined with bovine bone mineral (BBM) (experimental group) with that of autogenous cancellous bone alone (control group). We studied bilateral augmentations of the sinus floor in 6 adult sheep. BBM and mononuclear cells (MNC) were mixed and placed into one side and autogenous bone in the other side. Animals were killed after 8 and 16 weeks. Sites of augmentation were analysed radiographically and histologically. The mean (SD) augmentation volume was 3.0 (1.0) cm(3) and 2.7 (0.3) cm(3) after 8 and 16 weeks in the test group, and 2.8 (0.3) cm(3) (8 weeks) and 2.8 (1.2) cm(3) (16 weeks) in the control group, respectively. After 8 weeks, histomorphometric analysis showed 24 (3)% BBM, and 19 (11)% of newly formed bone in the test group. The control group had 20 (13%) of newly formed bone. Specimens after 16 weeks showed 29 (12%) of newly formed bone and 19 (3%) BBM in the test group. The amount of newly formed bone in the control group was 16 (6%). The results show that mononuclear cells, including mesenchymal stem cells, in combination with BBM as the biomaterial, have the potential to form bone.

Coronectomy as a surgical approach to impacted mandibular third molars: a systematic review

The aim of this systematic review was to evaluate the clinical effectiveness of the surgical technique of coronectomy for third molars extraction in close proximity with the inferior alveolar nerve.A literature survey carried out through PubMed, SCOPUS and the Cochrane Library from inceptions to the last access in January 31, 2014, was performed to intercept randomised clinical trials, controlled clinical trials, prospective cohort studies or retrospective studies (with or without control group) that examined the clinical outcomes after coronectomy. The following variable were evaluated: inferior alveolar nerve injury, lingual nerve injury, postoperative adverse effects, pulp disease, root migration and rate of reoperation. Ten articles qualified for the final analysis. The successful coronectomies varied from a minimum of 61.7% to a maximum of 100%. Coronectomy was associated with a low incidence of complications in terms of inferior alveolar nerve injury (0%-9.5%), lingual nerve injury (0%-2%), postoperative pain (1.1%-41.9%) and swelling (4.6%), dry socket infection (2%-12%), infection rate (1%-9.5%) and pulp disease (0.9%). Migration of the retained roots seems to be a frequent occurrence (2%-85.3%).Coronectomy appears to be a safe procedure at least in the short term, with a reduced incidence of postoperative complications. Therefore, a coronectomy can be indicated for teeth that are very close to the inferior alveolar nerve. If a second operation is needed for the remnant roots, they can be removed with a low risk of paresthesia, because the roots are generally receded from the mandubular nerve.

A new biological approach to guided bone and tissue regeneration.

The purpose of this study was to determine the potential of platelet-rich fibrin (PRF) membranes used for guided bone and tissue regeneration. A patient with insufficient alveolar ridge width in aesthetic zone was enrolled. The patients blood was centrifuged to obtain PRF membranes. Autogenous bone graft was mixed with bovine hydroxyapatite, PRF particles and applied to fill the defect. Five PRF membranes were placed over the bone mix. After 4 months a cone-beam CT was performed to evaluate bone regeneration. The use of PRF as cover membrane permitted a rapid epithelisation and represented an effective barrier versus epithelial cell penetration. After 4 months the site appeared precociously healed and the bone volume increased. This new approach represents a predictable method of augmenting deficient alveolar ridges. Guided bone regeneration with PRF showed limitation compared with guided bone regeneration using collagen membrane in terms of bone gain. The association of collagen membrane and PRF could be a good association.

Classification of impacted mandibular third molars on cone-beam CT images

Background Neurological involvement is a serious complication associated to the surgical removal of impacted mandibular third molars and the radiological investigation is the first mandatory step to assess the risk of a possible post-operative injury to the inferior alveolar nerve (IAN). The aim of this study was to introduce a new radiological classification that could be normally used in clinical practice to assess the relationship between an impacted third molar and mandibular canal on cone beam CT (CBCT) images. Material and Methods CBCT images of 80 patients (133 mandibular third molars) were independently studied by three members of the surgical team to draw a classification that could describe all the possible relationships between third molar and IAN on the cross-sectional images. Subsequently, the study population was subdivided according to this classification. The SPSS software, version 15.0 (SPSS® Inc., Chicago, Illinois, USA) was used for the statistical analysis. Results Eight different classes were proposed (classes 0-7) and six of them (classes 1-6) were subdivided in two subtypes (subtypes A-B). The distribution of classes showed a prevalence of buccal or apical course of the mandibular canal followed by lingual position and inter-radicular one. No differences have resulted in terms of anatomic relationship between males and females apart from a higher risk of real contact without corticalization of the canal when the IAN had a lingual course for female group. Younger patients showed an increased rate of direct contact with a reduced calibre of the canal and/or without corticalization. Conclusions The use of this classification could be a valid support in clinical practice to obtain a common language among operators in order to define the possible relationships between an impacted third molar and the mandibular canal on CBCT images. Key words:CBCT, classification, inferior alveolar nerve, third molars.

Localization of basicranium midline by submentovertex projection for the evaluation of condylar asymmetry.

The purpose of this research was to compare the reliability of two different methods for cranial midline localization through cephalometric analysis of mandibular condyle asymmetries. A retrospective cohort study was performed analyzing consecutively the SMV radiograms of 47 patients undergoing oral surgery before orthodontic treatment at the Dental School, University of Trieste (Italy) from 2003 to 2008. Two different cephalometric analyses were used to identify the basicranium midline (Tracing 1: initial landmarks = craniostat ear rods; Tracing 2: initial landmarks = spinosum foramina), and the left/right symmetry ratio (SR) for four parameters (condylar length, condylar angle, intra-condylar hemidistance, extra-condylar hemidistance) was calculated. The main result showed that no significant statistical difference between the SRs of the intra-condylar and extra-condylar hemidistance obtained with the same tracing was found (t-test; P = NS; C.I. 95%). Conversely, the difference between the SRs obtained with the two different tracings was statistically significant (t-test; P < 0.000; C.I. 95%). In conclusion, if the analysis of condylar asymmetries is performed in growing subjects, utilization of anatomic references such as the neurovascular foramina seems to guarantee a lower error compared to non-fixed references such as ear rods.

A novel INDEL mutation in the EDA gene resulting in a distinct X- linked hypohidrotic ectodermal dysplasia phenotype in an Italian family.

References 1 Lauria G, Hsieh ST, Johansson O et al. European Federation of Neurological Societies/Peripheral Nerve Society Guideline on the use of skin biopsy in the diagnosis of small fiber neuropathy. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society. Eur J Neurol 2010; 17: e44–e49. 2 Backonja MM, Attal N, Baron R et al. Value of quantitative sensory testing in neurological and pain disorders: NeuPSIG consensus. Pain 2013; 154: 1807–1819. 3 Rolke R, Baron R, Maier C et al. Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): standardized protocol and reference values. Pain 2006; 123: 231–243. 4 Schneider JC, Harris NL, El Shami A et al. A descriptive review of neuropathic-like pain after burn injury. J Burn Care Res 2006; 27: 524–528. 5 Altun V, Hakvoort TE, van Zuijlen PP, van der Kwast TH, Prens EP. Nerve outgrowth and neuropeptide expression during the remodeling of human burn wound scars. A 7-month follow-up study of 22 patients. Burns 2001; 27: 717–722. 6 Isoardo G, Stella M, Cocito D et al. Neuropathic pain in post-burn hypertrophic scars: a psychophysical and neurophysiological study. Muscle Nerve 2012; 45: 883–890. 7 Schuhknecht B, Marziniak M, Wissel A et al. Reduced intraepidermal nerve fibre density in lesional and nonlesional prurigo nodularis skin as a potential sign of subclinical cutaneous neuropathy. Br J Dermatol 2011; 165: 85–91. 8 Maddison B, Parsons A, Sangueza O, Sheehan DJ, Yosipovitch G. Retrospective study of intraepidermal nerve fiber distribution in biopsies of patients with nummular eczema. Am J Dermatopathol 2011; 33: 621– 623. 9 Berardesca E, Farage M, Maibach H. Sensitive skin: an overview. Int J Cosmet Sci 2013; 35: 2–8. 10 St€ander S, Schneider SW, Weishaupt C, Luger TA, Misery L. Putative neuronal mechanisms of sensitive skin. Exp Dermatol 2009; 18: 417–423. 11 Misery L, Bodere C, Genestet S, Zagnoli F, Marcorelles P. Small-fibre neuropathies and skin: news and perspectives for dermatologists. Eur J Dermatol 2014; 24: 147–153. 12 Benecke H, Lotts T, St€ander S. Investigational drugs for pruritus. Expert Opin Investig Drugs 2013; 22: 1167–1179. 13 Dhaka A, Viswanath V, Patapoutian A. Trp ion channels and temperature sensation. Annu Rev Neurosci 2006; 29: 135–161. 14 Denda M, Tsutsumi M, Denda S. Topical application of TRPM8 agonists accelerates skin permeability barrier recovery and reduces epidermal proliferation induced by barrier insult: role of cold-sensitive TRP receptors in epidermal permeability barrier homoeostasis. Exp Dermatol 2010; 19: 791–795. 15 Peier AM, Reeve AJ, Andersson DA et al. A heat-sensitive TRP channel expressed in keratinocytes. Science 2002; 296: 2046–2049. 16 St€ander S, Zeidler C, Lotts T, R€ ulander F, Dangelmaier J, Luger TA. Update on the antipruritic effect of aprepitant. Actadermato-Venerologica 2013; 5: 610–611. 17 Almeida TA, Rojo J, Nieto PM et al. Tachykinins and tachykinin receptors: structure and activity relationships. Curr Med Chem 2004; 11: 2045–2081. 18 St€ander S, Siepmann D, Herrgott I, Sunderk€ otter C, Luger TA. Targeting the neurokinin receptor 1 with aprepitant: a novel antipruritic strategy. PLoS ONE 2010; 5: e10968.

Biofilms Developed on Dental Implant Titanium Surfaces with Different Roughness: Comparison Between In Vitro and In Vivo Studies

Microbial biofilms developed on dental implants play a major role in perimplantitis’ pathogenesis. Many studies have indicated that surface roughness is the main feature favoring biofilm development in vitro, but its actual influence in vivo has still to be confirmed. In this study, the amount of biofilm formed on differently treated titanium surfaces, showing distinct roughness, has been examined both in vivo and in vitro by Confocal Laser Scanning Microscopy. In vitro studies availed of biofilm developed by Pseudomonas aeruginosa or by salivary bacteria from volunteer donors. In vivo biofilm production was obtained by exposing titanium discs to the oral cavity of healthy volunteers. In vitro experiments showed that P. aeruginosa and, to a lesser extent, salivary bacteria produce more biomass and develop thicker biofilms on laser-treated and sandblasted titanium surfaces with respect to machined ones. In vivo experiments confirmed that bacterial colonization starts on sites of surface unevenness, but failed to disclose biomass differences among biofilms formed on surfaces with different roughness. Our study revealed that biofilm developed in vitro is more easily influenced by surface features than biofilm formed by complex communities in the mouth, where the cooperation of a variety of bacterial species and the presence of a wide range of nutrients and conditions allow bacteria to optimize substrate colonization. Therefore, quantitative differences observed in vitro among surfaces with different characteristics may not be predictive of different colonization rates in vivo.

In vivo evaluation of chitosan-glycerol gel scaffolds seeded with stem cells for full-thickness mandibular bone regeneration

The aim of this study was to evaluate in vivo bone regeneration, mediated by adipose-derived stem cells (ADSCs), induced to differentiate into osteoblasts and carried by a scaffold gel. In the test group, bone regeneration was mediated by ADSCs, induced to differentiate into osteoblasts, and carried by a scaffold gel. In the control group a scaffold without cells was used. The scaffold, consisting of chitosan and glycerol phosphate, was maintained in situ by a cross-linked resorbable membrane. The osteogenic potential of ADSCs was confirmed by osteocalcin assay and Von Kossa staining performed before implantation. Histological assays detected an initial increase in bone formation in the test group compared with the control group. Microcomputed tomography analysis did not show significant differences between the two groups. Both histological and microcomputed tomography analysis were performed on the ex vivo specimens after a follow-up period of 8 weeks. We observed that differentiated ADSCs could increase bone regeneration and that the scaffold used here can be a suitable carrier to entrap and maintain the cells in situ. On the contrary, the membrane used was not functional in isolating the site of the defect from surrounding soft tissues and caused a significant inflammatory reaction.

Local vs general anaesthesia in the development of neurosensory disturbances after mandibular third molars extraction: A retrospective study of 534 cases.

Background The choice of the anaesthetic modality is one of the primary steps during planning of third molar surgery. The aim of the present study was to compare the risk of developing neurological injures of the inferior alveolar nerve (IAN) and lingual nerve (LN) in patients treated for wisdom teeth removal under general anaesthesia (GA) with a group treated under local anaesthesia (LA). Material and Methods This is an observational retrospective, unicentric study; between September 2013 and September 2014, 534 patients underwent third molar surgery, 194 (36,3%) under GA and 340 (63,7%) under LA by the same oral surgeon. Differences in the incidence of IAN and LN injures between groups have been statistically analyzed with Fisher exact test and estimated odd ratio for development of such complications has been calculated. Results In GA patients the incidence of IAN and LN injures was 4.6% and 2.1%, respectively while in the LA group it was and 0.3% and 0%, respectively. A significant difference in IAN and LN involvement between groups was observed (IAN lesion: Fisher exact test, p<0.001; LN lesions: Fisher exact test, p<0.05). The estimated odd ratio for development of IAN injures after GA was 16.49 (95% CI: 2.07-131.19) and was not calculable for LN injures because no cases were observed in the LA group. Conclusions Since GA is a perioperative variable that seems to significantly increase the risk of developing IAN and LN lesions, when treating patients that request GA, they must be adequately informed that an higher incidence of post-surgical sensory disturbances is expected. Key words:Third molars, general anaesthesia, local anaesthesia, inferior alveolar nerve, lingual nerve.