Home About us Contact
|
Home About us Contact | ||
|
|
||
Study Casts (study + cast)
Selected AbstractsAssociation of tightly locked occlusion with temporomandibular disordersJOURNAL OF ORAL REHABILITATION, Issue 3 2007M.-Q. WANG summary, The association between teeth loss and temporomandibular disorders (TMD) is still inconclusive. A kind of secondary changes of the occlusion after teeth lose called the tightly locked occlusion (TLO), defined as the occluding contact that delivers angled occlusal force on the drifted neighbour and/or the tipped antagonists of the lost posterior teeth, was hypothesized to be association with TMD. The study aimed at investigating the association between the TLO and TMD. A total of 113 posterior-teeth losing patients, 64 with TMD symptoms (group of TMD) and 49 without (group of TMD-Free) were included. Study casts and joint radiographs were made to diagnose the TLO and joint morphological changes. The simultaneous contribution of the potential variables of gender, age, tooth losing number, the TLO, joint symmetry and signs of osteoarthrosis shown on radiographs were tested through binary logistic regression analysis. In women, the TLO entered into logistic model, and had an effect on the incidence of TMD (P = 0·008). The odds ratio of with-TLO versus without-TLO is 2·6 (95% CI: 1·2, 5·8) after controlling for the effect of gender. Age, tooth lose number, joint asymmetry or osseous changes had no effect on the incidence of TMD. The tightly locked occlusion is associated with some signs and symptoms of TMD. Randomized controlled trials will be needed in further studies to test the hypothesis that treatment of a TLO, as defined in the present study, will have a beneficial effect on the signs and symptoms of TMD. [source] Measurements of Tooth Movements in Relation to Single-Implant Restorations during 16 Years: A Case ReportCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2005Torsten Jemt LSD ABSTRACT Background: Osseointegrated implants behave as ankylotic abutments, and their positions are not affected by dentofacial changes. Purpose: To measure changes in occlusion in relation to single implants in one patient after more than 15 years in function. Materials and Methods: One 25-year-old female was treated with two single implants in the upper central incisor and bicuspid area after trauma. Study casts made prior to treatment (1987) and after 16 years in function (2004) were scanned by means of an optical scanner. Using the palate as the reference, the models were placed in the same coordinate system and analyzed and compared in a computer-aided design (CAD) program. The results of the measurements of the casts were also compared with clinical photographs taken at the time of treatment (1988), after 9 years (1997), and after 16 years (2004) in function. Results: The clinical photographs showed obvious signs of implant infraposition after 9 years. New crowns were made in the incisor region after 15 years (2002), but signs of infraposition were again present at the final examination (2004). Measurements of the casts indicated small tooth movements with a pattern of slight eruption of upper teeth combined with a palatal inclination, mesial drift, and lingual inclination and crowding of the lower anterior teeth. The small measured vertical eruption of the teeth was less than the observed clinical infraposition of the implant crowns, indicating that the vertical position of the palatal may have changed in relation to the implants as well. Conclusion: Obvious dentofacial changes may take place in adult patients. Teeth may adjust for this, and no major problems may arise in the dentate patient. However, because the positions of implants are not affected by dentofacial changes, other patterns of clinical problems can be seen when implant patients present with these changes. The character and frequency of these dentofacial changes that may compromise implant treatment in the long term are not yet known. [source] Oral status of 35 subjects with eating disorders , A 1-year studyEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 4 2000Rolf Öhrn The aim was to record changes over time in the oral status of subjects with diagnosed eating disorders. The outpatient psychiatrist had referred to the hospital dental clinic 35 women (19,47 yr, median 27 yr) with eating disorders, diagnosed according to DSM III-R criteria. At the baseline examination, dental, medical and dietary histories were taken, and intra-oral clinical and radiographic examinations were supplemented by intra-oral photographs, study casts and salivary analysis. The subjects were re-examined 1 yr later. Together, the investigators assessed progression of tooth wear blindly by comparing coded study casts from the baseline and 12-month examinations. Progression of erosive tooth wear was recorded in almost half of the subjects. Several subjects had low unstimulated salivary flow rates (<0.1 ml/min) and very high counts of mutans streptococci and lactobacilli, both at baseline and 1 yr later. The flow rates for paraffin-stimulated saliva at baseline were significantly lower for subjects with progression of erosive tooth wear than for those without. Because of the increased susceptibility to both caries and erosion, patients with eating disorders should be encouraged to have regular dental check-ups. Test of salivary flow may serve as an indicator of patients' risk of progression of erosive tooth wear. [source] Digital Analysis of Experimental Human Bitemarks: Application of Two New MethodsJOURNAL OF FORENSIC SCIENCES, Issue 6 2006Nazar Al-Talabani B.D.S., Ph.D. ABSTRACT: Bitemark determination in forensic odontology is commonly performed by comparing the morphology of the dentition of the suspect with life-sized photographs of injury on the victim's skin using transparent overlays or computers. The purpose of this study is to investigate the suitability of two new different methods for identification of bitemarks by digital analysis. A sample of 50 volunteers was asked to make experimental bitemarks on the arms of each other. Stone study casts were prepared from upper and lower dental arches of each volunteer. The bitemarks and the study casts were photographed; the photos were entered into the computer and Adobe Photoshop software program was applied to analyze the results. Two methods (2D polyline and Painting) of identification were used. In the 2D polyline method, fixed points were chosen on the tips of the canines and a straight line was drawn between the two fixed points in the arch (intercanine line). Straight lines passing between the incisal edges of the incisors were drawn vertically on the intercanine line; the lines and angles created were calculated. In the painting method, identification was based on canine-to-canine distance, tooth width and the thickness, and rotational value of each tooth. The results showed that both methods were applicable. However, the 2D polyline method was more convenient to use and gave prompt computer-read results, whereas the painting method depended on the visual reading of the operator. [source] Accuracy, confidence and consistency in diagnosing Class III malocclusion with diagnostic records: a two-center studyORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 3 2000Peter Ngan The objective of this study was to determine the accuracy, confidence and consistency in diagnosing the Class III malocclusion in children by diagnostic records. Ten orthodontists from the state of West Virginia and 20 from the state of Ohio were asked to classify the dental and skeletal occlusion of eight patients. Six of the cases were patients with Class III malocclusion. Two cases, one with a Class II division 1 malocclusion and one with a Class I malocclusion, were used as distractors. Diagnosis of these cases was established by four published cephalometric analyses, which served as the ,gold standard', to determine the number of correct responses from the participants. Four faculty members were employed to confirm the cephalometric and clinical diagnosis of these cases with a full set of records. Participants were asked to diagnose the cases using only study casts and facial profile photographs for the first time. After an interval of 30 days, the procedure was repeated with the addition of lateral cephalograms and tracings. The accuracy in diagnosing malocclusion was determined by the percentage of correct responses. The level of confidence was determined by calculating the median of a 5-point graded response utilizing the following confidence values: 1=not at all, 2=slightly, 3=moderately, 4=very, 5=absolutely. Differences between ,with' and ,without' lateral cephalograms were analyzed non-parametrically using the Wilcoxon matched-pairs signed-ranks test. The results from both centers show the accuracy in dental classification of Class III malocclusion was quite good (83%±17.1% in the West Virginia group and 93%±14.1% in the Ohio group). The accuracy in skeletal classification was poor (72%±16.3 in the West Virginia group and 53%±7.03 in the Ohio group). The addition of lateral cephalograms and tracings did not improve the accuracy of dental or skeletal classification. However, clinicians felt more confident in their diagnoses with the information provided by lateral cephalograms and tracings. The consistency in dental and skeletal classification was fair and poor, respectively. These results suggest that clinicians are not consistent in diagnosing the Class III malocclusion and that skeletal classification of Class III malocclusion in children could be difficult. The addition of lateral cephalograms and tracings do not contribute to the accuracy of diagnosis. [source] Patient assessment and diagnosis in implant treatmentAUSTRALIAN DENTAL JOURNAL, Issue 2008NU Zitzmann Abstract As in any dental treatment procedure, a thorough patient assessment is a prerequisite for adequate treatment planning including dental implants. The literature was searched for references to patient assessment in implant treatment up to September 2007 in Medline via PubMed and an additional handsearch was performed. Patient assessment included the following aspects: (1) evaluation of patient's history, his/her complaints, desires and preferences; (2) extra-and intra-oral examination with periodontal and restorative status of the remaining dentition; (3) obligatory prerequisites were a panoramic radiograph and periapical radiographs (at least from the adjacent teeth) for diagnosis and treatment planning. Additional tomographs are required depending on the anatomic situation and the complexity of the planned restoration; (4) study casts are needed especially in more complex situations also requiring a diagnostic set-up, which can be tried-in and transferred into a provisional restoration as well as into a radiographic and surgical template. The current review clearly revealed the necessity for a thorough, structured patient assessment. Following an evaluation, a recommendation is given for implant therapy or, if not indicated, conventional treatment alternatives can be presented. [source] | ||||||||||