Home About us Contact
|
Home About us Contact | ||
|
|
||
Lower Incisors (lower + incisor)
Selected AbstractsIntentional replantation of an immature permanent lower incisor because of a refractory peri-apical lesion: case report and 5-year follow-upINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 3 2004S. Shintani Summary., We performed an intentional replantation of an immature lower incisor that had a refractory peri-apical lesion. The incisor was extracted and the peri-apical lesion was removed by curettage. The root canal of the tooth was then rapidly irrigated, and filled with a calcium hydroxide and iodoform paste (Vitapex®), after which the tooth was fixed with an arch wire splint. Five years later, no clinical or radiographic abnormalities were found, and the root apex was obturated by an apical bridge formation. A team of two dentists is essential to prevent a prolonged operation time, thus eliminating any of the causes of ankylosis. Furthermore, calcium hydroxide and iodoform paste, along with an arch wire splint retained with composite resin, led to good healing of the periodontal tissue after the intentional replantation. Our results indicate that intentional replantation is a useful method for an immature tooth with refractory peri-apical problems. [source] Microcephalia with mandibular and dental dysplasia in adult Zmpste24-deficient miceJOURNAL OF ANATOMY, Issue 5 2008F. De Carlos Abstract ZMPSTE24 (also called FACE-1) is a zinc-metalloprotease involved in the post-translational processing of prelamin A to mature lamin A, a major component of the nuclear envelope. Mutations in the ZMPSTE24 gene or in that encoding its substrate prelamin A (LMNA) result in a series of human inherited diseases known collectively as laminopathies and showing regional or systemic manifestations (i.e. the Hutchinson,Gilford progeria syndrome). Typically, patients suffering some laminopathies show craniofacial or mandible anomalies, aberrant dentition or facial features characteristic of aged persons. To analyse whether Zmpste24,/, mice reproduce the cranial phenotype observed in humans due to mutations in ZMPSTE24 or LMNA, we conducted a craniometric study based on micro-computer tomography (µCT) images. Furthermore, using simple radiology, µCT, µCT-densitometry and scanning electron microscopy, we analysed the mandible and the teeth from Zmpste24,/, mice. Finally, the structure of the lower incisor was investigated using an H&E technique. The results demonstrate that Zmpste24,/, mice are microcephalic and show mandibular and dental dysplasia affecting only the mandible teeth. In all cases, the lower incisor of mice lacking Zmpste24 was smaller than in control animals, showed cylindrical morphology and a transverse fissure at the incisal edge, and the pulpal cavity was severely reduced. Structurally, the dental layers were normally arranged but cellular layers were disorganized. The inferior molars showed a reduced cusp size. Taken together, these data strongly suggest that Zmpste24,/, mice represent a good model to analyse the craniofacial and teeth malformations characteristic of lamin-related pathologies, and might contribute to a better understanding of the molecular events underlying these diseases. [source] Craniofacial morphology in patients with hypophosphataemic vitamin-D-resistant rickets: a cephalometric studyJOURNAL OF ORAL REHABILITATION, Issue 7 2009S. H. AL-JUNDI Summary, Hypophosphataemic vitamin-D-resistant rickets (HVDRR) is a hereditary disease mainly transmitted as an X-linked dominant trait and characterized by certain general clinical signs (Filho HM, de Castro LC, Damiani D. Arq Bras Endocrinol Metab. 2006;50:802). In literature, only one study had been published in 1965 on the cephalometric findings in patients with HVDRR (Marks SC, Lindahl RL, Bawden JW. J Dent Child. 1965;32:259). This is the first detailed study on craniofacial characteristics of patients with HVDRR in the dental literature. The aim of this study was to determine the effect of HVDRR on the parameters of the craniofacial skeleton of young Jordanian patients using cephalometric analysis. Lateral cephalometric radiographs were made for 22 Jordanian children (aged 2,16 years) diagnosed with HVDRR. The cephalometeric parameters of HVDRR group were compared with those of normal control group matched for gender and chronological age using paired t -test. The HVDRR group had a significant increase in the SNBa angle (P < 0·01); as well as reduced anterior cranial base length (P = 0·01), reduced maxillary length, corpus mandibular length and mandibular height (P = 0·01, 0·04 and 0·008 respectively). The cranial base and gonial angles were significantly increased in diseased individual, but the SNA and ANB angles were significantly reduced (P = 0·018 and 0·000 respectively). The angulation of the lower incisor to mandibular plane was also significantly reduced in the diseased group compared with Jordanian norm (P = 0·004). Patients with HVDRR have deficiency in the anterior cranial base length, ramus height and cranial base angle. Patients with HVDRR also have class III skeletal relationship. [source] Relationship between tooth contacts in the retruded contact position and mandibular positioning during retrusionJOURNAL OF ORAL REHABILITATION, Issue 11 2006S. YAMASHITA summary, We conducted a series of studies with the purpose to investigate the locations of tooth contacts in the retruded contact position (RCP) and to discuss their significance in the stomatognathic system. In the present study, the relationship between the locations of RCP contacts and mandibular positioning during retrusion was examined. Thirty dentists and clinical residents were selected as subjects. One specialist in prosthetic dentistry examined each subject for the location of the RCP contacts. The mandibular positioning during retrusion was measured using a mandibular movement analysis system with six degrees of freedom. Originally programmed software was developed. Five reference points were selected: the central lower incisor (point I), the first molars on both sides (points RM and LM) and the condyles on both sides (points RC and LC). Tooth contact was observed most frequently at the second molar, followed by the first premolar. Points I, RM and LM all moved in an inferior-posterior direction, whereas points RC and LC moved in various directions ranging from superior-posterior to inferior-posterior. When the subjects were divided into two groups according to the most anterior tooth of occlusion in the RCP, the condylar positioning tended to be more superior in the group with molar contact than that with premolar contact. These results suggest that the locations of RCP contacts could be an important factor in jaw guidance during retrusion. [source] Rapidly progressive internal root resorption: a case reportDENTAL TRAUMATOLOGY, Issue 5 2008David Keinan Usually the process is asymptomatic and diagnosed upon routine radiographic examination. This case report presents a rapid progression of internal resorption related directly to traumatic injury. A 16-year-old female arrived at the emergency room after a mild extrusion of the mandibular incisors. The initial treatment included repositioning and splinting of the teeth. Radiographs performed at repositioning and splinting demonstrated normal configuration of the incisor's roots. Ten months later progressive internal resorption of the left mandibular first incisor was diagnosed. While treating this tooth similar process was detected in the right mandibular second incisor and in the mandibular left second incisor. The lower right first incisor reacted inconsistently to vitality test. As a result of the severe and rapidly progressive nature of the process, root canal treatments were performed in all lower incisors. The follow-up radiographs demonstrate arrest of the internal resorption process. [source] Oral piercing and oral trauma in a New Zealand sampleDENTAL TRAUMATOLOGY, Issue 5 2005J. A. Kieser Abstract,,, This study investigated the periodontal and dental trauma resultant from tongue and lip piercings in a convenience sample of 43 adult dental patients. Patients underwent an intra-oral examination followed by the administration of a questionnaire. Each patient was examined for lingual or buccal recession of the upper and lower incisors as well as the extent of abnormal toothwear or trauma on these teeth. Following bivariate analyses, regression analyses were conducted to test the study hypotheses and derive adjusted estimates for the dependent variables. Of the 43 individuals who participated (93.0% females; mean age 21 years; age range 14,34 years) 76.7% had a tongue piercing, 34.9% had a lip piercing, and 11.6% had both. Only four had had their piercing procedure provided by a doctor or dentist. Postpiercing complications were reported by 34.9%. Most of those with a labial piercing (80.0%) had 1+ labial site with gingival recession (GR), and almost one-third of those with a tongue piercing had at least one lingual site with GR. Age was a significant predictor of the prevalence of lingual recession, with the odds of having lingual recession increasing by 1.17 (95% CI 1.01, 1.35) for every year older than 14. Age was the only significant predictor of the number of lingual sites with recession, but was not a predictor of the prevalence of labial recession or the number of affected sites. There were no significant associations between piercings and abnormal toothwear or trauma. These findings suggest that oral piercings are associated with localized gingival recession, and that the providers of such procedures should ensure that, as part of the informed consent process, prospective patients are informed of the likelihood that their periodontal health may be compromised. [source] Longitudinal evaluation of GCF IFN-, levels and periodontal status in HIV+ patientsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2003T. Alpagot Abstract Background/Aim: Loss of periodontal support and related tooth loss is a common finding among HIV+ patients. The etiology of this destruction may be an increase in the levels of pro-inflammatory cytokines and subsequent increase in periodontal disease activity. The purpose of this study was to investigate the associations between gingival crevicular fluid interferon gamma (GCF IFN- ,) and clinical measures of periodontal disease in HIV+ individuals. We monitored GCF IFN- , and periodontal status of selected sites in 33 HIV+ subjects over a 6-month period. Method: Clinical measurements including gingival index, plaque index, bleeding on probing, probing depth, attachment loss (AL), and GCF samples were taken from four lower incisors and the upper right posterior sextant of each patient at baseline and 6-month visits by means of sterile paper strips. GCF levels of IFN- , were determined by sandwich ELISA assays. A progressing site was defined as a site that had 2 mm or more AL during the 6-month study period. Results: Twenty-five of the 264 examination sites showed 2 mm or more clinical AL during the 6-month study period. Significantly higher GCF levels of IFN- , were found at progressing sites than in nonprogressing sites (p<0.001). GCF levels of IFN- , were highly correlated with clinical measurements taken at baseline and 6-month visits (0.001 Tooth displacement due to occlusal contacts: a three-dimensional finite element studyJOURNAL OF ORAL REHABILITATION, Issue 12 2006S. GOMES DE OLIVEIRA summary, The use of the Finite Element Method (FE) is an appropriate way to study occlusal forces and tooth movement. The purpose of this study was to evaluate the effects of different occlusal contact patterns on tooth displacement in an adult dentition using a three-dimensional FE model of a human maxilla and mandible. Initially, images of a computerized tomography scan were redrawn in a computer program (CATIA) followed by the FE mesh construction. The MSC/Patran software was used to develop the FE mesh comprising 520 445 elements and 106 633 nodes. The MSC/Nastran program was utilized as pre and post-processor for all mathematical calculations necessary to evaluate dental and mandibular biomechanics. Four occlusal patterns were tested: FEM 1 , standard occlusal contacts; FEM 2 , removal of mesial marginal and mesial tripoidism contacts; FEM 3 , removal of distal marginal and distal tripoidism contacts; FEM 4 , similar to FEM 3 with added contacts between upper and lower incisors. Small changes in the standard distribution of occlusal contacts resulted in an imbalance of occlusal forces and changes in dental positioning. All simulations tested showed mesial displacement of posterior teeth. The most significant changes were registered in the model presenting unstable occlusal contacts when the anterior teeth were in occlusion (FEM 4). These findings may explain mandibular incisors crowding and maxillary incisors flaring as a result of small variations in dental contacts. [source] Factors affecting human supragingival biofilm composition.JOURNAL OF PERIODONTAL RESEARCH, Issue 4 2009Background and Objective:, Little is known regarding the factors that affect the microbial composition of supragingival biofilms. This study was designed to test the hypothesis that tooth location affects the microbial composition of supragingival plaque beyond the effect due to plaque mass as reflected by total DNA probe count. Material and Methods:, Supragingival plaque samples were taken from the mesiobuccal aspect of each tooth in 187 subjects (n = 4745 samples). All samples were individually analyzed for their content of 40 bacterial species using checkerboard DNA,DNA hybridization. Significance of differences in mean species counts and proportions were determined among tooth surfaces and six tooth type categories: molars, bicuspids, incisors/canines in the mandible and maxilla separately using the Kruskal,Wallis test. Stepwise multiple linear regression was employed to examine the relationship between species proportions and total DNA probe count, tooth location, periodontal and smoking status, age and sex. Results:, All species differed significantly among tooth types and among the six tooth categories. Higher plaque levels were seen on molars and lower incisors. Some differences observed between tooth types could be partly explained by the level of plaque. Teeth with high plaque mass exhibited high levels of Capnocytophaga gingivalis, Actinomyces naeslundii genospecies 2, Campylobacter rectus and Campylobacter showae. However, certain species, such as Veillonella parvula and Streptococcus sanguinis, differed significantly at different tooth locations despite similarities in plaque mass. Twenty of the test species exhibited a significant association with tooth location after adjusting for total DNA probe count and subject level factors. Conclusion:, While plaque mass was associated with differences in proportions of many species in supragingival biofilms, tooth location also was strongly associated with species proportions in both univariate and multivariate analyses. [source] Relationship of TMJ osteoarthritis,/,osteoarthrosis to head posture and dentofacial morphologyORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 1 2008H Ioi Structured Abstract Authors,,, Ioi H, Matsumoto R, Nishioka M, Goto TK, Nakata S, Nakasima A, Counts AL Objective,,, The purpose of this study was to test the hypothesis that there is a relationship between the temporomandibular joint (TMJ) osteoarthritis/osteoarthrosis (OA), head posture and dentofacial morphology. Design,,, Case,control study. Subjects and Methods,,, The subjects consisted of 34 Japanese females with TMJ OA (aged 24.7 ± 6.1 years) and a control group of 25 healthy Japanese females (aged 23.6 ± 1.3 years). Six cranio-cervical angular measurements were constructed for head posture analysis. Nine angular and three linear measurements were constructed for the skeletal hard tissue analysis. Five angular and one linear measurements were constructed for the dental hard tissue analysis. Unpaired t -tests were used to compare the mean differences of head posture measurements and dentofacial cephalometric measurements between the TMJ OA and the control group. Results,,, The TMJ OA group had significantly larger cranio-cervical angles (p < 0.05) and had more posteriorly rotated mandibles (p < 0.0001) than those in the control group. They also had a significantly shorter posterior facial height (p < 0.0001). The TMJ OA group had more retroclined lower incisors (p < 0.05). Conclusion,,, These results suggest that an association may exist between TMJ OA, head posture and dentofacial morphology. [source] Mammalian tooth marks on the bones of dinosaurs and other Late Cretaceous vertebratesPALAEONTOLOGY, Issue 4 2010NICHOLAS R. LONGRICH Abstract:, We describe bones from the Late Cretaceous of Alberta , including bones of large dinosaurs, a femur from the aquatic reptile Champsosaurus, and a dentary from the marsupial Eodelphis, that bear tooth marks made by animals with opposing pairs of teeth. Of the animals known from the Late Cretaceous of North America, only mammals are capable of making such tooth marks. In particular, multituberculates, which have paired upper and lower incisors, are the most likely candidates for the makers of these traces. The traces described here represent the oldest known mammalian tooth marks. Although it is possible that some of these tooth marks represent feeding traces, the tooth marks often penetrate deep into the dense cortices of the bone. This raises the possibility that, much as extant mammals gnaw bone and antler, some Cretaceous mammals may have consumed the bones of dinosaurs and other vertebrates as a source of minerals. However, none of the tooth marks described here resemble the extensive gnaw traces produced by Cenozoic multituberculates or rodents. This suggests that specialized gnawing forms may have been rare or absent in the Late Cretaceous of North America. [source] Paraconsistent Artificial Neural Network as Auxiliary in Cephalometric DiagnosisARTIFICIAL ORGANS, Issue 7 2010Mauricio C. Mario Abstract This work presents an application of the paraconsistent artificial neural network (PANN) in the analysis of cephalometric variables and provides an orthodontic diagnosis. An expert's analysis is subject to the inherent imprecision of measurements, registers, and individual variability of physician visual analysis. Patient input cephalometric values are compared with means drawn from individuals considered normal in the cephalometric point of view by the PANN. This reference is constituted by individuals from 6 to 18 years old, both genders. The applied cephalometric analysis was targeted to measure skeletal and dental discrepancies and established a cephalometric diagnosis. The analysis results in degrees of skeletal, anteroposterior, and dental discrepancy, pertinent to upper and lower incisors. A sample of 120 orthodontic patients was processed by the proposed model and three orthodontic experts. Comparisons between the model and the human expert's performance provided kappa indexes that varied from moderate to almost perfect agreement. The agreement between the model and specialist's performance was equivalent. In addition, the model pointed out contradictions presented in the data that were not noticed by the orthodontists, which highlight the contribution that this kind of system could carry out in the orthodontics decision support. [source] Influence of changing the chewing region on mandibular movementAUSTRALIAN DENTAL JOURNAL, Issue 1 2009K Hashii Abstract Background:, In the shortened dental arch condition, little is known of how patients adapt their jaw function during mastication to the new oral environment. This study aimed to investigate the changes in mandibular movements when the chewing region was changed from the first molar to the first premolar. Methods:, Thirty clinical residents with natural dentitions were recruited. The subjects were asked to chew a piece of beef jerky using either the first molar or the first premolar on the preferred chewing side. Three-dimensional trajectories of lower incisors and both condyles were analysed using a jaw movement tracking device with six degrees of freedom during the period between the onset and offset of electromyographic bursts from the masseter and anterior temporal muscles. Results:, The closing angle of the lower incisors for first premolar chewing was narrower in comparison with that for first molar chewing (p < 0.05). The lengths of the condylar trajectories and the maximum velocities of the condylar movement for first premolar chewing were smaller and slower, respectively, in comparison with those for first molar chewing (both sides; p < 0.01). Conclusions:, The mandibular movement during mastication might be changed to adapt the premolar chewing because of a loss of posterior occlusal supports. [source] Traumatic lingual ulcer in a child: Riga,Fede diseaseCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 2 2009A. M. Ceyhan Summary Riga,Fede disease RFD is an extremely rare, benign inflammatory disorder characterized by reactive, traumatic ulceration of the oral mucosa especially located on the tongue. It is most commonly associated with natal or neonatal teeth in newborns. Mucosal lesions are often caused by repetitive traumatic damage due to backward and forward motions of the tongue over the lower incisors. Failure to diagnose and treat these lesions properly may result in inadequate food intake, growth retardation and permanent lingual deformity. We report a 15-month-old healthy infant with tongue ulcer diagnosed as RFD based on history and clinical features. [source]
| | |||||||||