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Dental Casts (dental + cast)
Selected AbstractsMasseter muscle thickness as a predictive variable in treatment outcome of the twin-block appliance and masseteric thickness changes during treatmentORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 4 2010S Kiliaridis To cite this article: Kiliaridis S, Mills CM, Antonarakis GS: Masseter muscle thickness as a predictive variable in treatment outcome of the twin-block appliance and masseteric thickness changes during treatment Orthod Craniofac Res 2010;13:203,213 Structured Abstract Authors,,, Kiliaridis S, Mills CM, Antonarakis GS Objectives,,, To estimate the association of initial masseter muscle thickness with treatment outcomes using functional appliances and the effect of treatment on masseter muscle thickness. Material and Methods,,, Twenty-two children, aged 8,12, with skeletal and dental class II relationships and increased overjet were treated with twin-block appliances for 9,17 months, until a class I molar relationship and decreased overjet was achieved. Dental casts, lateral cephalograms, and ultrasonographic measurements of the masseter muscle were performed before and after treatment. Twenty-two children, aged 8,12, without immediate need for orthodontic treatment, served as controls. They were observed for 11,17 months, and ultrasonographic masseter muscle measurements were taken before and after the observation period. Results,,, Masseter muscles in treated children were thinner at the end of treatment, while untreated controls showed an increase in thickness. Treated children with thinner pre-treatment muscles showed greater mandibular incisor proclination, distalisation of maxillary molars, and posterior displacement of the cephalometric A point during treatment. Conclusion,,, Treatment of a dental class II relationship with functional appliances leads to mild atrophy of the masticatory muscles, possibly because of their decreased functional activity. The initial condition of the muscles may be associated with mandibular incisor proclination, and the position of maxillary first molars and A point. [source] Maxillary arch width in unoperated adult bilateral cleft lip and alveolus and complete bilateral cleft lip and palateORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 2 2010BS Latief To cite this article: Latief BS, Lekkas C, Kuijpers MAR: Maxillary arch width in unoperated adult bilateral cleft lip and alveolus and complete bilateral cleft lip and palate Orthod Craniofac Res 2010;13:82,88 Structured Abstract Authors,,, Latief BS, Lekkas C, Kuijpers MAR Objectives,,, To study maxillary arch width in adult patients with bilateral cleft lip and alveolus (BCLA) or with complete bilateral cleft lip and palate (BCLP), who have not had any surgery. Setting and Sampling Population,,, Eighteen patients with BCLA, 13 patients with BCLP, and 24 controls from remote areas of Indonesia collected over 10 years. Materials and Methods,,, Dental casts were digitized three-dimensionally using an industrial coordinate measuring machine (CCM) (Zeiss Numerex; Carl Zeiss®, Stuttgart, Germany). Transversal distance between molars was measured on the tip of the distobuccal cusp and the tip of the mesiobuccal cusp, and for premolars and canines, the tip of the buccal cusps was recorded. Means and standard deviations were calculated for all variables. t -Test was used to determine whether the mean values of the cleft groups showed significant differences from each other and from the controls. Level of significance was set at p < 0.05. Results,,, Transversal arch dimensions in the BCLA group were comparable to the controls except at the canine level. Intercanine distance, which is close to the alveolar cleft, was 4.3 mm (SE 1.4) smaller in the BCLA group (p = 0.002). In the BCLP group, a comparable pattern was found. At the canine level, mean transversal width was 7.2 mm (SE 1.9) smaller compared to the control group, but no significant differences were found in the other transversal dimensions. Conclusions,,, Small differences are found in transversal dimensions in patients with BCLA and BCLP compared to a control group. Differences are most outspoken in the area near the cleft. [source] Deciduous tooth crown size and asymmetry in strabismic childrenORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 4 2002T Heikkinen Structured Abstract Authors , Heikkinen T, Alvesalo L, Tienari J Objectives , To explore deciduous tooth crown dimensions in strabismic children and the relationship between the type of strabismus and tooth crown mesio-distal (M-D) and labio-lingual (L-L) size asymmetries. Material , Dental casts at mixed dentition of 2159 Collaborative Perinatal Study black and white children were measured, 123 of them strabismic at 1 year of age, age ranging from 6 to 12 years. Methods, Directional and fluctuating asymmetries in antimeric teeth were explored in various types of strabismus having unilateral, bilateral or alternating expression. ANOVA and T-square test were used for size comparisons and calculated asymmetries were explored by comparing the variances and Pearson correlations. Results , Strabismus was associated with significant M-D size increase of deciduous maxillary canines in black boys and white girls, black girls had size reduction in their mandibular canine, but white boys were unaffected. Right side size dominance was found in the strabismic children in the lower second deciduous molar M-D dimensions and in the children with alternating strabismus in their upper deciduous canine M-D dimensions. Children with unilateral strabismus had random fluctuating dental asymmetry in their upper deciduous second molar L-L dimensions when compared with healthy normals. Higher left-right correlations were found in lower second deciduous molar dimensions in strabismic girls when compared with that in controls and in strabismic boys, suggesting better developmental canalization in female. Conclusions , Asymmetries in the head area, such as promoted here in strabismic children, may have associations with asymmetries in the dentition, focusing the embryonal origins and timing of developmental processes. [source] Comparison of forces transmitted through different EVA mouthguardsDENTAL TRAUMATOLOGY, Issue 4 2006Craig F. Duhaime Abstract,,, Athletic mouthguards have been recommended for decades with varying levels of athlete acceptance. Issues related to compliance center around the ability to breath and speak while wearing the mouthguards. Fabrication techniques have changed over time to a two-layer ethylene vinyl acetate mouthguard fabricated on a high-pressure machine. The reported ideal thickness of these mouthguards has been somewhat variable depending on the sport and anticipated level of risk. Recent research however, has identified 4 mm as the optimal thickness of EVA. In this study an acrylic dental cast was fabricated and mounted to a drop impact fixture. Mouthguards of varying ply, thickness and palatal coverage were fabricated and tested in the fixture. Strain gauges and load cells were used to evaluate the effect of ply, thickness, and palatal coverage on the ability of these mouthguards to minimize transmitted forces. The purpose of this study was to identify those variables of mouthguard construction that will minimize the overall transmitted force of impact to the anterior dentition. [source] Changes in the bucco-lingual thickness of the mandibular alveolar process and skeletal bone mineral density in dentate women: a 5-yr prospective studyEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2005Grethe Jonasson After tooth extraction there is a great interindividual variation in the remodelling pattern of the alveolar process in edentulous areas, with some individuals losing little bone and others undergoing extensive resorption. However, little is known about possible longitudinal changes in the dentate region of the alveolar process of adults and if these are related to alterations in the skeletal bone mineral density (BMD). In a prospective study, on two occasions, 5-yr apart, the BMD of 117 women was determined in the distal forearm by using dual-energy X-ray absorptiometry, and the bucco-lingual thickness of the mandibular alveolar process was measured on dental casts by using a dial calliper. A decrease in the mean alveolar thickness, exceeding a cut-off value of 0.1 mm, was found in 60% of the women and an increase was found in 3% of the individuals. This decrease was 0.22 ± 0.20 mm in the posterior region and 0.16 ± 0.19 mm in the anterior region. The changes in alveolar thickness in the posterior region were significantly correlated to the BMD changes both on the mid-crestal level site and on the cervical level site. We conclude that the bucco-lingual thickness decreases with age in the dentate alveolar process, possibly owing to periosteal resorption related to skeletal bone loss. [source] Palatally displaced upper lateral incisors: relapse after orthodontic treatment and its correlation with dentoskeletal morphologyORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 4 2000M. Okamoto The purpose of the present study was to determine whether the relapse tendency of the palatally positioned upper lateral incisor differs in patients treated with or without premolar extraction, and if there is any correlation between the amount of upper lateral incisor relapse and pretreatment dentoskeletal morphology or post-treatment changes. Forty-six patients with bilateral palatally displaced upper laterals who also exhibit maxillary dental constriction were separated into two groups: a premolar extraction (30 cases) group and a non-extraction (16 cases) group. All subjects had undergone orthodontic treatment with quad helix and edgewise appliances, followed by a 2-year retention period. Differences in the amount of the upper lateral incisor relapse and their correlations with the dentoskeletal morphology before and after treatment were determined on the lateral and postero-anterior cephalograms and dental casts. Results revealed that the upper lateral incisor relapse in the extraction group was significantly greater (p=0.0002) than the relapse in the non-extraction group. There was a positive correlation between incisor relapse and the distance of lateral incisor movement in both groups (r=0.539; p=0.030). Relapse in the non-extraction group was correlated with the widths of the upper dental arch (r,,0.507, p,0.044), with the naso-maxillary variables before treatment (r=,0.514, p=0.041), and also with changes in the upper inter-premolar and inter-molar widths during retention (r=0.514, p=0.040). [source] Brief communication: Population variation in human maxillary premolar accessory ridges (MxPAR)AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010Scott E. Burnett Abstract The purpose of this brief communication is to report the results of an analysis of maxillary premolar accessory ridges (MxPAR), a common but understudied accessory ridge that may occur both mesial and distal to the central ridge of the buccal cusp of upper premolars. We developed a new five-grade scoring plaque to better categorize MxPAR variation. Subsequently, we conducted a population analysis of MxPAR frequency in 749 dental casts of South African Indian, American Chinese, Alaskan Eskimo, Tohono O'odham (Papago), Akimel O'odham (Pima), Solomon Islander, South African Bantu, and both American and South African Whites. Northeast Asian and Asian-derived populations exhibited the highest MxPAR frequencies while Indo-European samples (South African Indians, American and South African Whites) exhibited relatively low frequencies. The Solomon Islanders and South African Bantu samples exhibited intermediate frequencies. Our analysis indicates that statistically significant differences in MxPAR frequency exist between major geographic populations. As a result, the MxPAR plaque has now been added to the Arizona State University Dental Anthropology System, an important contribution as maxillary premolar traits are underrepresented in analyses of dental morphology. Am J Phys Anthropol 2010. © 2009 Wiley-Liss, Inc. [source] Prevalence and side preference for tooth grinding in twinsAUSTRALIAN DENTAL JOURNAL, Issue 3 2006KV Dooland Abstract Background: Estimates of the prevalence of tooth grinding in children range considerably, reflecting different methods of recording. The main aims of this study were to determine the prevalence of tooth grinding in monozygotic (MZ) and dizygotic (DZ) twin pairs by assessing wear faceting on the primary canines, and to compare the faceting on the right and left to determine whether children have a side preference for grinding. Methods: The sample consisted of 116 MZ twin pairs and 124 dizygous DZ twin pairs, all participants in an ongoing study of dento-facial development at the dental schools in Adelaide and Melbourne. Evidence of wear faceting on primary maxillary and mandibular canine tips was recorded from dental casts, and the side with the larger wear facet recorded. Types of occlusal relationship, handedness, zygosity and gender were also recorded, and associations between variables analysed statistically. Results: Canine tip wear facets were found in 100 per cent of the sample, and grinding was lateralized in 59 per cent of children. MZ twin pairs showed a higher discordance for grinding side preference than DZ twin pairs (33.8 per cent compared with 16.8 per cent), providing evidence of a mirror-imaging effect for grinding side preference. There was no strong evidence that individuals had the same preference for grinding side and handedness, although right-handers (RH) showed a preference for a grinding side more often than non-righthanders (NRH) (63.6 per cent compared with 51.2 per cent), consistent with previous findings that RHs display more cerebral lateralization than NRHs. Conclusions: Tooth grinding appears to be a universal phenomenon in children and is commonly expressed more on one side than the other. The significantly higher discordance for grinding side preference in MZ twin pairs compared with DZ twin pairs may reflect a mirror-imaging effect in the former. However, at present we have no evidence to suggest that handedness and preferred tooth grinding side are associated. [source] | ||||||||||