Concept: Posterior superior alveolar artery
SUMMARYTo quantitatively evaluate on lateral cephalograms horizontal, vertical, and angular changes in the position of the maxillary first molar based on the presence and absence of erupted maxillary second molars when it is distalized with the XBow appliance.In this retrospective study, a total of 102 consecutively treated cases were assessed. Lateral cephalograms were obtained at the start and after completion of active treatment with the XBow appliance. In one group of patients, distal movement of the maxillary first molars was performed before the eruption of maxillary second molars; in the other group of patients, both first and second maxillary molars were simultaneously moved distally. All cephalograms were superimposed on palatal plane using the method of best-fit. In order to compare the mean horizontal, vertical, and angular changes in molar position between the treatment groups and gender, a multivariate analysis of covariance (MANCOVA) was performed with the pre-treatment class II severity used as a covariate. Regression analysis was also performed to further explore any possible relationships between the predictor variables and the quantity and quality of distalization.A MANCOVA revealed that the eruption stage of the maxillary second molar did not have a significant effect on the change in position of the maxillary first molar after treatment with a XBow appliance.When distalizing maxillary first molars with a XBow appliance, there is no difference in the amount of distalization in patients with erupted and unerupted maxillary second molars.
INTRODUCTION: The aim of this retrospective investigation was to evaluate the postoperative quality of life after endodontic surgery in maxillary molars when a sinus membrane perforation occurred and platelet concentrates were used. MATERIALS AND METHODS: Included patients were treated by microsurgical endodontic treatment in molar and premolar maxillary regions between 2007 and 2010. Patients who fulfilled the inclusion criteria were screened. Data from the quality of life questionnaire were analyzed. The use of plasma rich in growth factors (PRGF) (test group) was compared with a control group when a Schneiderian membrane perforation occurred during endodontic surgery performed with a modern technique in maxillary molars and premolars. RESULTS: A total of 20 patients (12 in the control group and eight in the test group) fulfilled the inclusion criteria. No differences were evaluated at baseline for clinical parameters. Significantly improved patients' quality of life was observed in the test group considering symptoms as swelling, bad breath or taste, and pain. Functional activities were less impaired in the test group and swelling was significantly higher in the control group. In the test group, pain was significantly lower than the control group during the first 6 days after surgery and also, the consumption of painkillers was lower for patients belonging to the test group even if it was not statistically significant. DISCUSSION: In general, a small sinus membrane perforation (less than 6 mm) during endodontic surgery did not cause severe complications. The use of platelet concentrates could be effective in reducing the impact on patients' quality of life, decreasing pain and surgery side effects as well as swelling.
The aim of this study was to evaluate the effect of glide path preparation on the surface topography changes of WaveOne and OneShape single files using atomic force microscopy analysis. Two commercially available brands of single file systems were analyzed, including 15 specimens/brand as following: Group I; WaveOne 0.08/25 (Dentsply Maillefer, Ballaigues, Switzerland) and Group II; OneShape 0.06/25 (Micro Mega, Besançon, France). In each group, 3 new files were subjected to AFM analysis as received from manufacturer, and 12 files were analyzed after preparation of root canals. A total of 20 human maxillary molar teeth were selected. In each group, 12 files were divided into 4 subgroups according to instruments that were used in one or three root canals with or without a previous glide path (n = 3). After preparation the surface analysis of single files was performed on 11 different points located along a 3-mm section starting at the tip of each file using AFM. Root mean square (RMS) values were recorded to investigate the surface features of endodontic files. The differences between RMS values were tested by one-way ANOVA. There was no statistically significant difference between the groups (p > 0.05). Creation of a glide path did not affect the surface topography of single file systems. SCANNING 9999:XX-XX, 2014. © 2014 Wiley Periodicals, Inc.
A transpalatal arch (TPA) directly connecting the maxillary first molars can be used in passive (for stabilization) and active (for molar or segment movement) modes. Activation may be symmetric or asymmetric. This study was performed to analyze the effectiveness of TPAs for transverse expansion treatment by measuring both the force systems they deliver and the clinical tooth movements thus achieved.
Sinus floor elevation via the lateral window approach represents a reliable technique for bone augmentation in the atrophic posterior maxilla. It is known that sinus membrane elevation leads to new bone formation. This prospective clinical study compared a specific technique in sinus membrane elevation with a conventional sinus floor augmentation (xenogenous/autogenous bone) in a human split mouth model.
To analyze the stress distribution on the PDL of the maxillary first molar in a mixed dentition Class III malocclusion, using a Hyrax-type appliance and maxillary protraction.
The relationship between radiographic findings and the occurrence of oroantral perforation is controversial. Few studies have quantitatively analyzed the risk factors contributing to oroantral perforation, and no study has reported multivariate analysis of the relationship(s) between these various factors. This retrospective study aims to fill this void.
We aimed to consolidate all available data on worldwide third molar agenesis frequencies, with a particular emphasis on exploring the factors leading authors to find contradictory results for the demographic and morphologic predictors of this anomaly. A total of 12,376 studies were originally identified, then narrowed down to 1,312 for title/abstract screening. On the basis of our inclusion and exclusion criteria, we selected 92 studies, containing 100 effect sizes and 63,314 subjects, for systematic review and metaregression. The worldwide rate of agenesis was found to be 22.63% (95% confidence interval = 20.64% to 24.76%), although the estimates ranged from 5.32% to 56.0%. Our subgroup analyses revealed that women are 14% more likely than men to have agenesis of ≥1 third molars and that maxillary agenesis was 36% more likely than mandibular agenesis in both sexes. Furthermore, we found that having agenesis of 1 or 2 molars was most common, while agenesis of 3 or 4 molars was least common. Finally, we found large differences among agenesis frequency depending on geographic region. This information is expected to be of use not only to clinicians and patients but also to policy makers, given the implications for third molar extraction protocols.
This study explores the morphological differences between the enamel-dentine junction (EDJ) of maxillary and mandibular molars of Neanderthals (n = 150) and recent modern humans (n = 106), and between an earlier Neanderthal sample (consisting of Pre-Eemian and Eemian Neanderthals dating to before 115 ka) and a later Neanderthal sample (consisting of Post-Eemian Neanderthals dating to after 115 ka). The EDJ was visualised by segmenting microtomographic scans of each molar. A geometric morphometric methodology compared the positioning of the dentine horns, the shape of the marginal ridge between the dentine horns, and the shape of the cervix. We also examined the manifestation of non-metric traits at the EDJ including the crista obliqua, cusp 5, and post-paracone tubercle. Furthermore, we report on additional morphological features including centrally placed dentine horn tips and twinned dentine horns. Our results indicate that EDJ morphology can discriminate with a high degree of reliability between Neanderthals and recent modern humans at every molar position, and discriminate between the earlier and the later Neanderthal samples at every molar position, except for the M3 in shape space. The cervix in isolation can also discriminate between Neanderthals and recent modern humans, except at the M3 in form space, and is effective at discriminating between the earlier and the later Neanderthal samples, except at the M(2)/M2 in form space. In addition to demonstrating the taxonomic valence of the EDJ, our analysis reveals unique manifestations of dental traits in Neanderthals and expanded levels of trait variation that have implications for trait definitions and scoring.
The objective of this study was to investigate whether multistranded fixed retainers prevented overeruption of unopposed mandibular second molars in maxillary first molar extraction cases.