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Maxillary Arch (maxillary + arch)
Selected AbstractsDental arch morphological and dimensional characteristics in Jordanian children and young adults with ,-thalassaemia majorINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 2 2005A. AL-WAHADNI Summary. Objective. , The aim of this study was to examine the arch dimensions of Jordanian patients with ,-thalassaemia major in comparison with an unaffected control group. Methods. , The sample consisted of 24 patients who suffered from ,-thalassaemia major (mean age = 13·9 ± 3·1 years) and an unaffected control group (mean age = 13·5 ± 2·9 years) matched for dental age, sex, and incisor and molar relationships. The unaffected control group was randomly selected from four public schools in the Governate of Irbid-Jordan. Alginate impressions were taken of the maxillary and mandibular dental arches of all participants. All measurements of the arch dimensions were made on the casts using an electronic digital sliding calliper. Results. , In the mandibular arch, when compared with the patients with thalassaemia, the unaffected control group subjects showed a (statistically) significantly larger incisor width, larger arch depth, and larger left and right anterior arch lengths (1·18, 2·58, and 1·85 and 1·12 mm, respectively). In the maxillary arch, there was a statistically significant difference in the mean incisor width (± 2·16 mm), arch depth (± 3·14 mm), inter-molar width (± 1·21 mm) and in the left anterior arch length (± 1·97 mm). The canine widths, premolar widths, left and right posterior arch length, and curve of Spee of both arches showed no statistically significant differences between the two groups. Conclusion. , When compared to unaffected subjects, patients with ,-thalassaemia major exhibited: a narrower maxilla; a shorter maxilla and mandible; and smaller incisor widths for the maxillary and mandibular arches. [source] Three-dimensional finite element analysis of the facial skeleton on simulated occlusal loadingJOURNAL OF ORAL REHABILITATION, Issue 7 2001Martin D. Gross Development of predictive models of occlusal loading of the facial skeleton will be of value for prosthetic design in oral rehabilitation. A 3-D finite element (FE) model of a human skull, based on CT scans, was constructed to analyse strain and stress distribution in the facial skeleton caused by simulated occlusal loading. Vertical loads were applied simulating loading of the full maxillary arch and unilateral single point occlusal loading of maxillary molar, pre-molar, canine and incisor sites. Strain and stress regimes from Von Mises (VM) failure criteria and extension and compression diagrams showed even distribution of strain following loading of the full maxillary arch throughout the facial elements. For individual points, the highest VM concentrations were consistently located on the facial aspect several mm above the loading site. Strain trajectories divided into a ,V-shaped' pattern, from the loading point into medial and lateral branches with higher VM values in the medial. As the same load was applied from the posterior to anterior region, VM values increased on all facial areas. Strain patterns were less symmetric and there was an increase in strain in the alveolar arch and around the rim of the nasal cavity. The overall picture of the facial skeleton is of a vertical plate enabling it to withstand occlusal stresses by in-plane loading and bending in its own plane. The most efficient distribution of load was on maxillary full arch loading with the most unfavourable strain concentrations occurring on loading in the anterior region. [source] Acellular dermal allograft for vestibuloplasty,an alternative to autogenous soft tissue grafts in preprosthetic surgical procedures: A clinical reportJOURNAL OF PROSTHODONTICS, Issue 2 2003Monish Bhola DDS Various vestibular extension procedures have been described in the literature over the past 6 decades, including the use of free gingival grafts. An acellular dermal allograft has been used as a substitute for autogenous soft tissue grafts in root coverage procedures. This clinical report describes the use of such an allograft as a substitute for palatal donor tissue in the vestibular extension of an edentulous maxillary arch with multiple frenum attachments before fabrication of a complete denture. In this patient, healing was uneventful, and 6-month clinical observations demonstrated an apical positioning of the mucogingival junction with an increase in vestibular depth, and the absence of multiple frenae. The acellular dermal allograft appears to be a useful substitute for autogenous palatal grafts in preprosthetic surgery. This approach has many advantages over the free gingival graft, including no donor site morbidity, unlimited availability, and better color match. [source] Pressure generated on a simulated oral analog by impression materials in custom trays of different designsJOURNAL OF PROSTHODONTICS, Issue 3 2002Radi Masri BDS Purpose To measure the pressure exerted by maxillary edentulous impressions composed of 3 commonly used impression materials using four different impression tray configurations. Materials and Methods The study was performed using an oral analog that simulated an edentulous maxillary arch. Three pressure transducers were imbedded in the oral analog, 1 in the mid-palate area and the other 2 in the right and left ridge (maxillary first premolar areas). Custom trays of 4 different configurations were fabricated. The 3 impression materials tested were irreversible hydrocolloid, light-body and medium-body vinyl polysiloxane, and polysulfide. A total of 128 impressions were made. The custom tray and the oral analog were mounted using a reline jig. A Satec universal testing machine was used to apply a constant pressure of 2 kg/cm2 over a period of 5 minutes on the loaded custom tray. The pressure was recorded every 10 seconds. Factorial analysis of variance and Tukey's multiple comparison test were used to analyze the results. Results A significant difference in the pressure produced using different impression materials was found (p,0.001). Irreversible hydrocolloid and medium-body vinyl polysiloxane produced a significantly higher pressure than light-body vinyl polysiloxane and polysulfide impression materials. The presence of holes and/or relief did not significantly alter the magnitude of pressure. Conclusions All impression materials produced pressure during maxillary edentulous impression making. Tray modification was not important in changing the amount of pressure produced. The impression materials used had more effect on the pressure produced during impression making on the simulated oral analog. [source] | ||||||||||