Search results for "Maxilla"
showing 10 items of 450 documents
Short implants (8mm) versus longer implants (≥8mm) with lateral sinus floor augmentation in posterior atrophic maxilla: A meta-analysis of RCT`s in h…
2019
Background One of the greatest challenges that dentists face today is to rehabilitate severe atrophied alveolar ridges in partially and completely edentulous patients with implants. Despite the high survival rate of implants placed next to sinus elevation, this technique presents complications that can be avoided by placing short implants, an option that also presents high survival rates. For this reason, the aim of this study is to compare the survival rate, marginal bone loss and complications associated with short implants (<8 mm) versus longer implants (≥8mm) placed with lateral sinus floor elevation in posterior atrophic maxillae. Material and Methods A literature search was conducted …
How much incisor decompensation is achieved prior to orthognathic surgery?
2013
Objectives: To quantify incisor decompensation in preparation for orthognathic surgery. Study design: Pre-treatment and pre-surgery lateral cephalograms for 86 patients who had combined orthodontic and orthognathic treatment were digitised using OPAL 2.1 [http://www.opalimage.co.uk]. To assess intra-observer reproducibility, 25 images were re-digitised one month later. Random and systematic error were assessed using the Dahlberg formula and a two-sample t-test, respectively. Differences in the proportions of cases where the maxillary (110 0 +/- 6 0 ) or mandibular (90 0 +/- 6 0 ) incisors were fully decomensated were assessed using a Chi-square test (p<0.05). Mann-Whitney U tests were used …
Paramblypterus duvernoyi(Actinopterygii): skull morphology and intra-specific variation, and its implications for the systematics of paramblypterid f…
1999
ABSTRACT More than 300 specimens of Paramblypterus duvernoyi from four lakes of the Lower Permian of Germany are examined to determine intra-specific variation of this species and to revise the diagnosis of the genus Paramblypterus. For the first time, a three-dimensional model of the skull and the snout of Paramblypterus is reconstructed. A partial tooth bearing premaxilla, which forms the anterior most part of the gape, is described; in contrast, the absence of a premaxilla had until now been considered a synapomorphy of the genus Paramblypterus. Information obtained from the study of P. duvernoyi has required a new revision of Paramblypterus gelberti. A comparison between the two species…
Plywood Jig—A New Technique for Root Canal Curvature Measurement
2021
The successful outcome of endodontic treatment is dependent on complete cleaning, shaping as well as three dimensional obturation of the root canal system. A conventional radiograph is a two-dimensional replication of a three-dimensional object and does not provide any conclusive evidence for canal curvatures. An accurate knowledge of the tooth anatomy and curvature is essential to avoid procedural errors. 100 freshly extracted human teeth were used in this study. Digital images were obtained using the plywood JIG and Schneider’s technique. These images were analyzed using the VixWin Pro digital image analyzing software (Gendex system). Statistical analysis was done using paired t test. The…
Effectiveness of interceptive treatment of class III malocclusions with skeletal anchorage: A systematic review and meta-analysis
2017
Recently, new strategies for treating class III malocclusions have appeared. Skeletal anchorage appears to reduce the dentoalveolar effects while maximising the orthopaedic effect in growing patients. The purpose of this systematic review and meta-analysis is to examine the effectiveness of bone anchorage devices for interceptive treatment of skeletal class III malocclusions. Searches were made in the Pubmed, Embase, Scopus and Cochrane databases, as well as in a grey literature database, and were complemented by hand-searching. The criteria for eligibility were: patients who had undergone orthodontic treatment with skeletal anchorage (miniplates and miniscrews). Patients with syndromes or …
Root repair after damage due to screw insertion for orthodontic miniplate placement
2019
Background: The aim of this investigation was to describe the healing reactions following root damage caused by placement of a miniplate anchorage system.Material and Methods: In 4 beagle dogs, 4 titanium miniplates (2 self-tapping screws per miniplate) were placed in each maxilla, after drilling of pilot-holes. Six fixation screws were unintentionally inserted damaging the root of maxillary canines. Two weeks later, half of the miniplates were loaded with a coil spring. Two dogs were euthanized 7 weeks after placement of the miniplates, while the remaining two after 29 weeks. Histological sections were prepared, microradiographed, observed under U.V. light, then stained and analysed under …
The effect of pregnancy on orthodontic tooth movement in rats
2012
Introduction: The purpose of this study was to investigate the effect of pregnancy on orthodontic tooth movement in Wistar rats. Material and Methods: Forty eight female three-month old Wistar rats with an average weight of 250 ±25 g r were selected and randomly divided into two experimental (pregnant) and control groups (non-pregnant). Maxillary central incisors were tipped distally by insertion of springs exerting 30g force. Two, seven and fourteen days after spring insertion animals were sacrificed. Then the mesioincisal distance between maxillary incisors were measured. Subsequently, histological sections were prepared to count osteoclasts under a light microscope. The data on the exten…
Cranial circulation of the pen-tailed tree shrewPtilocercus lowii and relationships of Scandentia
1994
The major cranial arteries and veins are described for a 30-mm crown-rump length fetus of the pen-tailed tree shrewPtilocercus lowii, and comparisons are made with cranial vessels reported in the tree shrewTupaia and with the vascular pattern reconstructed for primitive eutherians.Ptilocercus shares a number of derived features of the cranial circulation withTupaia, which, therefore, represent synapomorphies of tree shrews (Tupaiidae, Scandentia). Included are (1) the enclosure of the intratympanic portion of the internal carotid artery in a bony canal that is floored proximally and distally by the entotympanic and by the petrosal in between, (2) the enclosure of the intratympanic portion o…
Evaluation of the effects of different groove length and thickness of the retainers on the retention of maxillary anterior base metal resin bonded re…
2012
Objectives: The resin-bonded fixed partial dentures have gained immense popularity in recent years as they are more conservative, esthetic, economic and easily fabricated. However debonding is considered the most common cause of failure of resin bonded prosthesis. The objective of the study were to compare the effects of different groove lengths and thickness of retainers on retention of maxillary anterior base metal resin bonded retainers. Study Design: Twenty five metal dies of maxillary central incisor duplicated from pure typhodont teeth (maxillary left central incisors) prepared to receive retainer for resin bonded fixed partial denture having different test designs were made. Five tes…
Implant-supported overdenture with horizontal insertion for treating the edentulous atrophic maxilla: A case series
2020
Abstract Statement of problem Rehabilitation of edentulous patients with severe maxillary atrophy is a clinical challenge. Although several treatment options are available, the implant-supported overdenture has been widely advocated. However vertical insertion implant-supported overdentures have drawbacks, including wear, aging, and the continuous maintenance of retention systems. Whether an implant-supported overdenture with a horizontal insertion pathway can overcome these problems is unclear. Purpose The purpose of this observational study was to determine the clinical and biological behavior of a new type of implant-supported overdenture with a horizontal insertion pathway over a mean c…