Does endodontics influence radiological detection of external root resorption? an in vitro study.

BACKGROUND: External root resorption (ERR) has a multifactorial etiology and is difficult to diagnose, which means that is continues to be of research interest. This work mainly aims to determine whether external root resorption can be differentially detected in root-filled versus non-endodontically treated teeth using digital periapical radiography (DPR) and cone-beam computed tomography (CBCT). METHODS: The Checklist for Reporting In-vitro Studies (CRIS) guidelines were followed throughout this study. This experiment highlights the preparation and generation of standardized synthetic teeth measured on three-dimensional records converted into Digital Imaging and Communication on Medicine (DICOM) file format. Twelve replicate maxillary incisors were randomized into two groups: (G1) six non-endodontically treated, and (G2) six endodontically treated teeth. In both groups, actual tooth lengths of all specimens were measured and compared with measurements obtained using DPR and CBCT. Simulated ERR lesions [0.12, 0.18, 0.20 mm × 0.5 mm depth in the mesial, distal and palatal apical regions] were created progressively, radiographic images were recorded, and 24 DPRs and 96 CBCTs were obtained in total. Eight blinded, previously calibrated researchers made a total of 1920 measurements (using Horos Software). Data were analyzed using the Shapiro-Wilk, ANOVA, Kruskal-Wallis and Wilcoxon rank post-hoc tests [Bonferroni correction in multiple comparison tests (p < 0.05)]. RESULTS: ICC values for intra- and inter-examiner agreement were appropriate. DPR overestimated ERR detection compared to the actual and CBCT measurements [Mean diff = 0.765 and 0.768, respectively]. CBCT diagnosis of ERR lesions in specimens without root canal treatment was significantly more accurate than DPR diagnoses on both non-endodontically and endodontically-treated specimens [p = 0.044; p = 0.037, respectively]. There was an 18.5% reduction in sensitivity in all DPR diagnoses made on endodontic teeth versus those made on non-endodontically treated teeth. For the smallest ERR lesions, this sensitivity was even more marked, with 27.8 and 25% less sensitivity, respectively. CONCLUSIONS: The results of this study highlight that both CBCT and DPR are good diagnostic methods for ERR. Nevertheless, root canal filling material influences diagnostic capability in ERR. The clinical significance was that the presence of intracanal material reduces the detection and diagnosis of ERR by DPR in teeth with root canal treatment.

Reabsorción radicular apical externatras la ortodoncia: Factores clínicos ydiagnósticos y análisis de redes de genesrelacionados / External apical root resorption after orthodontic treatment: clinical and diagnostic factors and analysis of related gene networks

Introducción: La reabsorción radicular apical externa (EARR) provocada por las fuerzas ortodóncicas representa uno de los efectos iatrogénicos más indeseables del tratamiento. Se pretende establecer una relación entre las variables diagnósticas y clínicas del tratamiento con la aparición y severidad de la reabsorción radicular apical externa agresiva (aEARR). Adicionalmente, la red de interrelaciones genéticas sirve para la generación de hipótesis en la correlación de variaciones genéticas, previamente asociadas con aEARR, con otras enfermedades. Métodos: Se realizó un estudio de asociación mediante una selección de 240 pacientes clasificados en dos grupos, basándose en la presencia o ausencia de a EARR. Se realizó un análisis descriptivo y una regresión logística binaria condicional tipo backward entre las variables y el desarrollo de aEARR. Se seleccionaron 5 variantes (STAG2, RP1-30E17.2, P2RX7, SPP1 y TNFRSF11A) asociadas a una mayor predisposición al desarrollo de aEARR y se realizó un análisis de redes. Resultados: Exclusivamente la variable tiempo de tratamiento obtuvo resultados estadísticamente significativos (IC: 95%; p=0,007) en relación con la aEARR. En el análisis de redes se encontró relación de 4 variantes genéticas con diferentes etapas del proceso patológico de la EARR que se relacionaron con 6 patologías: artritis, osteoartrosis, enfermedad autoinmune, lupus eritematoso, hepatitis C y EARR. Conclusiones: El único factor que se asoció con una mayor prevalencia de aEARR es el tiempo de duración del tratamiento. Cualquier vía que pueda tener relación con el proceso inflamatorio y, por tanto, con el proceso reabsortivo, puede tener una implicación mayor/menor de manera directa o indirecta en el desarrollo de la EARR (AU)

Introduction: External apical root resorption (EARR) caused by orthodontic forces represents one of the most undesirable iatrogenic effects of treatment. The aim of this study is to establish a relation between the diagnostic and clinical variables of treatment with the appearance and severity of aggressive external apical root resorption (aEARR). Additionally, the network of genetic interrelationships offers the generation of hypotheses in the correlation of genetic variations, previously associated with aEARR, with other diseases. Methods: An association study was performed using a selection of 240 patients classified into two groups based on the presence or absence of aEARR. A descriptive analysis of the data along with a backward conditional binary logistic regression was performed between the variables and aEARR. Five variants (STAG2, RP1-30E17.2, P2RX7, SPP1 and TNFRSF11A) associated with an increased predisposition to aEARR were selected and network analysis was performed. Results: Only the treatment time variable obtained statistically significant results (CI: 95%; p=0.007) in relation to aEARR. In the network analysis, 4 genetic variants were found to be related to different stages of the pathological process of aEARR, which were associated with 6 pathologies: arthritis, osteoarthrosis, autoimmune disease, lupus erythematosus, hepatitis C and EARR. Conclusions: The only factor associated with a higher prevalence of aEARR is the treatment duration. Any pathway that may be related to the inflammatory process and therefore to the resorptive process may have a greater/lesser involvement directly or indirectly in the development of aEARR (AU)

Sub-clustering in skeletal class III malocclusion phenotypes via principal component analysis in a southern European population.

The main aim of this study was to generate an adequate sub-phenotypic clustering model of class III skeletal malocclusion in an adult population of southern European origin. The study design was conducted in two phases, a preliminary cross-sectional study and a subsequent discriminatory evaluation by main component and cluster analysis to identify differentiated skeletal sub-groups with differentiated phenotypic characteristics. Radiometric data from 699 adult patients of southern European origin were analyzed in 212 selected subjects affected by class III skeletal malocclusion. The varimax rotation was used with Kaiser normalization, to prevent variables with more explanatory capacity from affecting the rotation. A total of 21,624 radiographic measurements were obtained as part of the cluster model generation, using a total set of 55 skeletal variables for the subsequent analysis of the major component and cluster analyses. Ten main axes were generated representing 92.7% of the total variation. Three main components represented 58.5%, with particular sagittal and vertical variables acting as major descriptors. Post hoc phenotypic clustering retrieved six clusters: C1:9.9%, C2:18.9%, C3:33%, C4:3.77%, C5:16%, and C6:16%. In conclusion, phenotypic variation was found in the southern European skeletal class III population, demonstrating the existence of phenotypic variations between identified clusters in different ethnic groups.

Effectiveness of Biology-Based Methods for Inhibiting Orthodontic Tooth Movement. A Systematic Review.

INTRODUCTION: Several experimental studies in the literature have tested different biology-based methods for inhibiting or decreasing orthodontic tooth movement (OTM) in humans. This systematic review investigated the effects of these interventions on the rate of tooth movement. STUDY DESIGN: Electronic [MedLine; SCOPUS; Cochrane Library; OpenGrey;Web of Science] and manual searches were conducted up to January 26th, 2016 in order to identify publications of clinical trials that compared the decreasing or inhibiting effects of different biology-based methods over OTM in humans. A primary outcome (rate of OTM deceleration/inhibition) and a number of secondary outcomes were examined (clinical applicability, orthodontic force used, possible side effects). Two reviewers selected the studies complying with the eligibility criteria (PICO format) and assessed risk of bias [Cochrane Collaboration's tool]. Data collection and analysis were performed following the Cochrane recommendations. RESULTS: From the initial electronic search, 3726 articles were retrieved and 5 studies were finally included. Two types of biology-based techniques used to reduce the rate of OTM in humans were described: pharmacological and low-level laser therapy. In the first group, human Relaxin was compared to a placebo and administered orally. It was described as having no effect on the inhibition of OTM in humans after 32 days, while the drug tenoxicam, injected locally, inhibited the rate of OTM by up to 10% in humans after 42 days. In the second group, no statistically significant differences were reported, compared to placebo, for the rate of inhibition of OTM in humans after 90 days of observation when a 860 nm continuous wave GaAlA slow-level laser was used. CONCLUSIONS: The currently available data do not allow us to draw definitive conclusions about the use of various pharmacological substances and biology-based therapies in humans able to inhibit or decrease the OTM rate. There is an urgent need for more sound well-designed randomized clinical trials in the field.

Are there any differences between first and second primary molar pulpectomy prognoses? A retrospective clinical study.

AIM: To determine if there are any significant differences between the prognoses of pulpectomies done on first and second primary molars of the upper and lower dental arch. MATERIALS AND METHODS: Study Design: The clinical study included 55 children who had undergone 86 pulpectomy treatments, 41 on the first molars and 45 on the second molars. The root canal filling material consisted of a paste based on Walkhoff formula, containing Kri-1, calcium hydroxide and meta-cresol formaldehyde. The same clinician carried out all pulpectomies. RESULTS: After the analysis there were a total of 7 treatment failures (3 in the upper arch and 4 in the lower). Four of the 7 failures were first primary molars and three were second primary molars. STATISTICS: There were no significant differences in the prognoses of the different kinds of primary molars. CONCLUSION: The anatomy of the primary molars changes considerably. Significant differences were not observed in the prognosis of different types of primary molars after pulpectomy.

Cellular and Molecular Pathways Leading to External Root Resorption.

External apical root resorption during orthodontic treatment implicates specific molecular pathways that orchestrate nonphysiologic cellular activation. To date, a substantial number of in vitro and in vivo molecular, genomic, and proteomic studies have supplied data that provide new insights into root resorption. Recent mechanisms and developments reviewed here include the role of the cellular component-specifically, the balance of CD68+, iNOS+ M1- and CD68+, CD163+ M2-like macrophages associated with root resorption and root surface repair processes linked to the expression of the M1-associated proinflammatory cytokine tumor necrosis factor, inducible nitric oxide synthase, the M1 activator interferon γ, the M2 activator interleukin 4, and M2-associated anti-inflammatory interleukin 10 and arginase I. Insights into the role of mesenchymal dental pulp cells in attenuating dentin resorption in homeostasis are also reviewed. Data on recently deciphered molecular pathways are reviewed at the level of (1) clastic cell adhesion in the external apical root resorption process and the specific role of α/ß integrins, osteopontin, and related extracellular matrix proteins; (2) clastic cell fusion and activation by the RANKL/RANK/OPG and ATP-P2RX7-IL1 pathways; and (3) regulatory mechanisms of root resorption repair by cementum at the proteomic and transcriptomic levels.

Intrusive Luxation in Primary Teeth: A Case Report.

BACKGROUND: Intrusive luxation, also called central dislocation, is often the result of an axial impact in the apical direction, moving the tooth within the alveolar bone. This is possibly one of the most traumatic injuries, since the displacement of a tooth within its socket implies extensive and acute involvement of the periodontal ligament, bone damage and rupture of the neurovascular bundle. The close relationship between the apexes of the primary teeth and the developing permanent successor in turn can lead to multiple complications, which are greater when the permanent tooth is affected in the early stages of development. METHODS: The present paper describes a case of intrusion in primary teeth and its evolution following initial diagnosis as avulsion at the time of trauma. RESULTS: The upper right central incisor, initially diagnosed as avulsed, was lodged in the floor of the right nostril, and was surgically extracted through the nose. CONCLUSIONS: In cases of intrusion of primary teeth, it is essential to diagnose the direction of the displaced tooth to rule out injury to the successor and thus prevent the occurrence of sequelae in the permanent dentition.

Osteopontin gene SNPs (rs9138, rs11730582) mediate susceptibility to external root resorption in orthodontic patients.

OBJECTIVE: External apical root resorption (EARR) is a frequent iatrogenic effect of orthodontic treatment. Substantial variability in responses to postorthodontic EARR has been observed among patients even when similar treatment protocols were used. This observation suggests that environmental and/or genetic variations between individuals may confer susceptibility or resistance to developing EARR. The objective of this study is to determine whether variants in the osteopontin gene, an essential mediator in the odontoclast fusion and attachment process, are positively/negatively associated with postorthodontic EARR. MATERIALS AND METHODS: Genetic screening of eighty-seven orthodontic patients was performed for two polymorphisms in the osteopontin gene cluster (rs9138 and rs11730582). Subjects were divided into groups, according to the presence or absence of EARR (>2 mm). Genotype distributions and allelic frequencies were calculated using the chi-square test. Logistic regression analysis was used to assess the extent to which clinical-related parameters interfered with the EARR. Odds ratios (OR) and 95% confidence intervals were also calculated. RESULTS: Data from this study show that subjects heterozygous and homozygous for the most frequent allele of the osteopontin gene at position 89261521 [OR: 0.035 (P = 0.035*) (allele A)] and 89253600 [OR: 0.20 (P = 0.025*) (allele T)], respectively, are protected against postorthodontic EARR. Nevertheless, a highly significant association was found in the comparative analysis of homozygous subjects [2/2 (CC)] for the osteopontin gene (rs9138), resulting in an increased risk of suffering postorthodontic EARR[OR: 4.10; P = 0.045*; CI: 95%]. Subjects who were homozygous [2/2 (CC)] for the osteopontin gene (rs11730582) were more likely, and to a greater extent, to be affected with EARR [OR: 11.68; P < 0.039*; CI: 95%] compared with other genotypes. CONCLUSION: Variations in the osteopontin gene (rs9138 and rs11730582) are determinants of a genetic predisposition to suffer EARR secondary to orthodontic treatment.

Revascularization of immature permanent teeth with apical periodontitis.

The aim of this minireview was to identify and review the scientific evidence regarding regenerative endodontic protocols claiming to revascularize permanent immature teeth with apical periodontitis. The literature was identified using the PubMed/MEDLINE, Scopus, Scirus, EMBASE and Cochrane databases up to February 2013. Studies were selected independently by two different researchers (kappa index: 0.88), based on established inclusion/exclusion criteria. The methodological quality of the reviewed papers was classified as high, medium or low (HQ, MQ, LQ). The search strategy identified 285 titles. Nine studies, both human and animal based, were selected after application of the criteria (LQ:5; MQ:4). In most of these studies (seven of nine), the revascularization protocol included a triple antibiotic combination as canal disinfectant for a period of 1-4 weeks after blood clot formation (LQ:5; MQ:4), although there is no clear consensus about the treatment protocol. Two studies reported tooth discoloration after the revascularization process (LQ:2), and only three (LQ:1; MQ:2) reported a success rate of 54.9% in dogs and 73.6% and 80% in humans, respectively. Revascularization of immature permanent teeth with apical periodontitis is possible and preferable to apexification. Nevertheless, there is a widespread lack of randomized clinical trials and blinded measures. In addition, the small sample sizes that are common in these studies as well as the generally low quality of the analysed publications require the results to be viewed with caution. There is a high risk of bias, with a low quality of available information, for developing clinical guidelines for regenerative endodontic protocols; rigorous randomized clinical trials are therefore needed.

A new three-dimensional analysis of asymmetry for patients with craniofacial syndromes.

OBJECIVES: The use of three-dimensional computed tomography (3D-CT) analyses represents a substantial improvement in planning treatment. The aim of this study is to introduce a new three-dimensional (3D) analysis of clinical value for evaluating asymmetry in cases of craniofacial syndrome. SUBJECTS AND METHODS: Virtual 3D models were reconstructed from CT images of 62 normal subjects (35 males and 27 females), more than 18 years old. Measurements of asymmetrical skeletal and dentoalveolar relationships were evaluated and standardized data obtained. The feasibility of the new 3D craniofacial analysis was then evaluated on one patient with severe maxillomandibular asymmetry in the form of hemifacial microsomia. RESULTS: Standardized 3D data from the analysis were obtained and classified into 6 maxillary measurements, eight mandibular measurements and seven dentoalveolar process measurements. No significant differences were found between males and females (U-Mann-Whitney test, P > 0.05). Useful data of clinical value was provided for planning orthodontic and surgical treatment of asymmetries, as well as a diagnostic chart. CONCLUSION: This method is useful for the clinical evaluation of asymmetry in craniofacial syndromes. The use of 3D analysis facilitates surgical and orthodontic treatment planning.

Do the smiles of the world's most influential individuals have common parameters?

The aim of this study was to determine - on the basis of the most recent yearly listings - whether there were any common measurable variables associated with the smiles of the world's most influential people. A total of 168 subjects were selected from the lists of Time magazine's 100 most influential people during the period 2006-2010. Smiling frontal view photographs were obtained. Thirty-six variables for each subject were traced and measured using photogrammetric analysis to obtain qualitative and quantitative proportions and measurements. Differences with respect to gender, occupation and year of listing were tested to 95% significance, using the Student's t-test and the Kruskal-Wallis test. The chi-squared test was used for qualitative variables. Irrespective of gender or occupation, the similar quantifiable characteristics of the smiles of the most influential subjects were the following: vertical upper lip proportion, smile width, incisor exposure, buccal corridor ratio, smile symmetry index and intra-dental proportions (P > 0·05). Other qualitative standards were as follows: smile symmetry, the buccal corridors and smile arc, direction of occlusal cant and the degree of deviation between maxillary and facial midlines. Differences were found for gingival display and smile height parameters (P = 0·001). The smiles of the world's most influential people revealed common standards, regardless of occupation or gender, which may play a decisive role in the expressions of influential faces.

Current concepts on the effect of environmental factors on cleft lip and palate.

The aim of this study was to investigate the effect of environmental factors, such as tobacco, alcohol and folic acid intake, obesity, stressful events, low blood levels of zinc and fever during pregnancy, on the incidence of cleft lip and/or palate (CL±P). An electronic search was performed in the Cochrane Reviews, the ISI Web of Knowledge, PubMed and Scopus, along with a manual search to identify other relevant case-control and cohort studies. Quality assessments and an evaluation of publication bias were undertaken. Statistical heterogeneity was examined, and odds ratios (ORs) and 95% confidence intervals (CI) estimated using the random effects model. Of 372 articles initially retrieved, 28 studies were selected as eligible for meta-analysis. No evidence of publication bias was found using funnel plot analysis and the Egger linear regression method. Many studies were classified as low quality due to inadequate case-control data. On the basis of this research, maternal factors most associated with CL±P were: tobacco (OR 1.48), alcohol (OR 1.28), folic acid intake (OR 0.77), obesity (OR 1.26), stressful events (OR 1.41), low blood zinc levels (OR 1.82), and fever during pregnancy (OR 1.30). Folic acid intake by the mother reduced the risk of CL±P in offspring (OR 0.77).

Association between craniofacial asymmetry and unilateral temporomandibular joint sounds in adult patients using 3D-computed tomography.

OBJECTIVES: The purpose of this study was to investigate the possible relationship between unilateral temporomandibular joint (TMJ) sounds and craniofacial asymmetry, using 3D-computed tomography (CT) measurements. SUBJECTS AND METHODS: Forty-one reconstructed 3D-CT models of adult subjects were measured to analyze craniofacial asymmetry. Subjects were divided into two groups depending on the presence (n = 20) or absence (n = 21) of unilateral joint sounds, and the results compared using the Mann-Whitney U-test. To investigate the association between these parameters, the Pearson correlation coefficient was calculated. RESULTS: Asymmetries in the maxillary and mandibular structures were statistically significant (P < 0.05) for subjects with unilateral TMJ sounds and for controls, except in the case of maxillary rotation and mandibular ramus height (P > 0.05). The highest deviations found were frontal and lateral ramal inclination, goniac angle and canting of occlusal plane. CONCLUSIONS: Adult patients with unilateral joint sounds may have skeletal jaw asymmetry and a canted occlusal plane.

Interleukin 1 gene cluster SNPs (rs1800587, rs1143634) influences post-orthodontic root resorption in endodontic and their contralateral vital control teeth differently.

AIM: To investigate whether the genetic variants of the interleukin-1 gene cluster (IL1) are associated with a possible genetically induced variability in post-orthodontic external apical root resorption (EARR) in root filled teeth and their control counterparts with vital pulps. METHODOLOGY: One hundred and forty-six maxillary premolars were evaluated radiographically following orthodontic treatment. Genetic screening was performed on orthodontic patients for two single-nucleotide polymorphisms (SNPs: rs1800587 and rs1143634) in the IL1 gene cluster. Subjects were divided into two groups according to the presence or absence of radiographic post-orthodontic EARR (>2 mm) in root filled teeth and their controls with vital pulps. Logistic regression analysis was performed to obtain an adjusted estimation between EARR and IL1 polymorphisms. Allelic frequencies, genotype distributions, and adjusted odds ratio (OR), at 95% confidence interval, were also calculated. RESULTS: Whilst no clear statistical association was found for gene variations in IL1A, a sound association was found in the comparative analysis of subjects homozygous [2/2(TT)] for the IL1B gene, which resulted in a two times increased risk of suffering post-orthodontic EARR in root filled teeth [OR, 2.032 (P = 0.031); CI,1.99-14.77] when compared with their controls with vital pulps. There was, however, a shared predisposition to EARR in controls with vital pulps and root filled teeth of subjects homozygous for allele 1 [OR, 5.05 (P = 0.002)] and [OR, 2.77 (P = 0.037)], respectively. CONCLUSIONS: Genetic variations in the interleukin-1ß gene (rs1143634) predispose root filled teeth to EARR for matched pairs secondary to orthodontic treatment in a different way from their control teeth with vital pulps in subjects homozygous for allele 2 [2/2(TT)].

Retrospective long-term evaluation of autotransplantation of premolars to the central incisor region.

AIM: This retrospective case-series study aimed to examine the long-term outcomes of autogenously transplanted premolars. METHODOLOGY: Twelve patients in whom donor premolars were used to replace maxillary central incisors lost by trauma were clinically and radiologically monitored. Standardized clinical and radiographic records were systematically obtained during the follow-up period of 14 years, to determine the influence of specific clinical criteria on the overall success rate of transplantation. RESULTS: The success rate of premolar autotransplantation in the maxillary central incisor area was 80% after 14 years follow-up. The highest success rate occurred in those teeth transplanted with two-thirds of full root development. Complete pulp obliteration was positively related to autotransplant viability, followed by root formation in the bony crypt. CONCLUSIONS: Autotransplantation of donor teeth, at the stage of ½ to ¾ of their expected root length, can provide a successful treatment solution for over 14 years.

Postorthodontic external root resorption is associated with IL1 receptor antagonist gene variations.

OBJECTIVE: External apical root resorption (EARR) is a frequent iatrogenic effect of orthodontic treatment. Patients with genetic variants in the interleukin 1 gene have been related to an increased risk of suffering EARR. The objective of this study is to determine whether variants in the interleukin 1 receptor antagonist gene are positively/negatively associated with interleukin 1 gene polymorphisms, particularly in relation to the clinical features of EARR patients. MATERIALS AND METHODS: Genetic screening of 54 orthodontic patients was performed for three polymorphisms (rs1800587, rs1143634 and rs419598) in the IL1 gene cluster. Subjects were divided according to the presence or absence of EARR of more than 2 mm. The genotype distributions and allelic frequencies were calculated by the chi-square-test. Odds ratios (OR) and 95% confidence intervals were also calculated. RESULTS: A highly significant association was found in the comparative analysis of homozygous subjects [1/1(CC)] for the IL1B gene, resulting in an increased risk of suffering postorthodontic EARR (OR: 3.47; P = 0.027; CI: 95%). While no association was found for the IL1A gene (P = 0.097), subjects who were homozygous [1/1(TT)] for the IL1RN gene were more likely to be affected with EARR (OR: 6.75; P = 0.001; CI: 95%). CONCLUSION: Variations in the interleukin 1 receptor antagonist gene (rs419598) - and not only in the IL1B gene (rs1800587) - are determinants of a predisposition to postorthodontic EARR.

Maxillary protraction at early ages. The revolution of new bone anchorage appliances.

PURPOSE: An update is provided on the different types of early treatment for class III malocclusions of maxillary origin. There is an increasing tendency to prescribe maxillary orthopedic treatment with skeletal anchorage, with the purpose of enhancing the skeletal and reducing the dentoalveolar effects--offering a management option for children with important deformations that otherwise would have to wait until adult age to receive surgical treatment. METHOD: A literature review has been made of maxillary bone orthopedic traction appliances in growing children with class III malocclusions. A Medline (PubMed) search was made using the following MeSH terms: Cephalometric, Child, Malocclusion class III/therapy, Extraoral traction appliances, Palatal expansion, Bone plates, Skeletal anchorage, Orthodontic anchorage. RESULTS: Many articles show that the greatest maxillary advances are obtained at very early ages, though with a greater tendency towards relapse. However skeletal anchorage has been seen to afford a lesser relapse rate and greater dentofacial orthopedic efficiency due to its low dentoalveolar impact. In any case, further randomized clinical studies are needed to firmly establish the quantifiable differences in terms of maxillary advance, optimum traction age, optimum traction appliance and potential side effects. At present, the incorporation of surgically inserted bone anchorage appliances (miniplates and miniscrews) offers a purely orthopedic approach to treatment, with minimization of the undesirable side effects of traditional dentofacial orthopedic compensation based on dentoalveolar anchorage. Nevertheless, further studies are needed to consolidate the supporting scientific evidence in this field.

The use of gene therapy vs. corticotomy surgery in accelerating orthodontic tooth movement.

OBJECTIVE: Alveolar corticotomy surgery is an adjunctive therapy for reducing orthodontic treatment duration. The activation pathways of bone resorption involved in the tooth movement (TM) process are directly linked to the receptor activator of the nuclear factor-kB ligand (RANKL). Whether similar molecular pathways through RANKL, are shared by the acceleratory TM process (corticotomy-induced or not), sustained acceleration would therefore be expected with transgenic overexpression of this factor. We hypothesize that maintaining transgenic overexpression of RANKL will accelerate TM under force over time rather than at the beginning of therapy only; this contrasts with the corticotomy procedure. MATERIAL AND METHODS: We transfected the pcDNA3.1(+)-mRANKL transgene in vitro into NIH3T3 cells, then evaluated by PCR, Western blot and ex vivo resorption assay. Quantification of RANKL immunofluorescence, fluorescence-based tartrate-resistant acid phosphatase+ (TRAP+) osteoclast counts and histological analyses of the bone resorption area were performed and clinically correlated after a 32-day in vivo experiment comparing corticotomy and gene therapy. RESULTS: In vitro experiments resulted in increased level of RANKL protein (46%, p<0.05) and greater mineral resorption (39%, p<0.05) compared to the controls. In vivo results showed increased RANKL immunoexpression for both corticotomy (twofold) and transfection groups (threefold) after 10 days. After 32 days, a similar result was obtained for the transfected group but not for the surgery group. These data correlate with the clinical effect of decelerating TM in the surgery group. CONCLUSIONS: Selective gene therapy with RANKL has been experimentally tested as an alternative method to corticotomy surgery, showing higher effectiveness than surgical methods used for acceleratory purposes in orthodontics.

Potential role of HDAC inhibitors in cancer therapy: insights into oral squamous cell carcinoma.

Histone deacetylases (HDACs) are enzymes that are involved in the remodeling of chromatin and play a key role in the epigenetic regulation of gene expression. In addition, the activity of non-histone proteins can be regulated through HDAC-mediated hypoacetylation. In recent years, inhibition of HDACs has emerged as a potential strategy to reverse aberrant epigenetic changes associated with cancer, and several classes of HDAC inhibitors have been found to have potent and specific anti-cancer activities in preclinical studies. Many researchers have highlighted the need to determine specific HDAC isotypes related to different tumor types in order to develop selective drugs for specific isoforms and avoid side effects. We summarize recent advances in the understanding of the molecular events that underlie the epigenetic changes in different tissue carcinomas, focusing on oral squamous carcinoma. The role of epigenetics in oral squamous cancer remains poorly understood, and further descriptive studies of specific HDAC member alterations are required to form the basis for future clinical trials.

Aplicación clínica de la terapia génica al movimiento dentario ortodóncico. Comparativa frente a la corticotomía alveolar / No disponible

El movimiento dentario ortodóncico se sustenta en bases biomoleculares y genéticas específicas en cada paciente. Sin embargo, existen determinados nexos comunes que rigen la velocidad del movimiento dentario a través de la estructura ósea alveolar. La disminución en el tiempo de tratamiento ortodóncico constituye aún hoy un reto pendiente por los profesionales de la materia, dependiendo éste directamente de la biología ósea. En la efervescente actualidad son muchos los autores que proponen la corticotomía alveolar como una técnica de apoyo a la ortodoncia en búsqueda de una aceleración inducida del movimiento dentario ortodóncico. Sin embargo, tal aceleración radica en última instancia en las bases biológicas del conocido como fenómeno de aceleración regional (RAP) desencadenado en el entorno óseo. Por otro lado, las vías moleculares de activación osteoclásticas y por tanto de reabsorción ósea, están íntimamente relacionadas con el (..) (AU)