Kirsi Sipilä

PURPOSE: To conduct a systematic review to evaluate the evidence of possible benefits and accuracy of digital impression techniques vs. conventional impression techniques. MATERIALS AND METHODS: Reports of digital impression techniques versus conventional impression techniques were systematically searched for in the following databases: Cochrane Central Register of Controlled Trials, PubMed, and Web of Science. A combination of controlled vocabulary, free-text words, and well-defined inclusion and exclusion criteria guided the search. RESULTS: Digital impression accuracy is at the same level as conventional impression methods in fabrication of crowns and short fixed dental prostheses (FDPs). For fabrication of implant-supported crowns and FDPs, digital impression accuracy is clinically acceptable. In full-arch impressions, conventional impression methods resulted in better accuracy compared to digital impressions. CONCLUSIONS: Digital impression techniques are a clinically acceptable alternative to conventional impression methods in fabrication of crowns and short FDPs. For fabrication of implant-supported crowns and FDPs, digital impression systems also result in clinically acceptable fit. Digital impression techniques are faster and can shorten the operation time. Based on this study, the conventional impression technique is still recommended for full-arch impressions.

OBJECTIVE: The aim of the study was to evaluate the association between psychosocial aspects of temporomandibular disorders (TMD) and oral health-related quality-of-life (OHRQoL) and, secondly, to investigate the gender differences in these associations using patient and non-patient groups. MATERIALS AND METHODS: The sample of the study consisted of 79 patients with TMD and 70 non-patients. The data was collected by Finnish versions of the RDC/TMD Axis II profile and Oral Health Impact Profile (OHIP-14) questionnaires. The associations between Axis II profile sub-scales and OHIP prevalence were evaluated using chi-square tests, as stratified by group status (TMD patients and non-patient controls) and by gender. The association between OHIP prevalence and Axis II profile sub-scales were evaluated using logistic regression analysis, adjusted by age, gender and group. RESULTS: OHIP prevalence (those reporting at least one problem) was 90.9% in the patient group and 33.3% in the non-patient group (p < 0.001, chi-squared test). OHIP prevalence was higher among those scoring higher on all RDC/TMD Axis II profile sub-scales, i.e. graded chronic pain status, depression and non-specific physical symptoms with pain items included and with pain items excluded. The associations were significant in the non-patient group. Women showed statistically significant associations of OHIP prevalence with all Axis II sub-scales. Among men, OHIP prevalence associated with GCPS and somatization. The logistic regression analysis showed that OHIP prevalence associated significantly with somatization and depression. CONCLUSIONS: TMD associate with OHRQoL through multiple ways, linked with depression and somatization. These findings emphasize the importance of early and effective treatment of TMD.

Tooth development is a highly heritable process which relates to other growth and developmental processes, and which interacts with the development of the entire craniofacial complex. Abnormalities of tooth development are common, with tooth agenesis being the most common developmental anomaly in humans. We performed a genome-wide association study of time to first tooth eruption and number of teeth at one year in 4,564 individuals from the 1966 Northern Finland Birth Cohort (NFBC1966) and 1,518 individuals from the Avon Longitudinal Study of Parents and Children (ALSPAC). We identified 5 loci at P<5x10(-8), and 5 with suggestive association (P<5x10(-6)). The loci included several genes with links to tooth and other organ development (KCNJ2, EDA, HOXB2, RAD51L1, IGF2BP1, HMGA2, MSRB3). Genes at four of the identified loci are implicated in the development of cancer. A variant within the HOXB gene cluster associated with occlusion defects requiring orthodontic treatment by age 31 years.

The evidence supporting the use of stabilisation splints in the treatment of temporomandibular disorders (TMD) is scarce and a need for well-controlled studies exists. The aim of this randomised, controlled trial study was to assess the efficacy of stabilisation splint treatment on TMD. The sample consisted of 80 consecutive referred patients who were randomly assigned to the splint group (n = 39) and the control group (n = 41). Subjects in the splint group were treated with a stabilisation splint, whereas subjects in the control group did not receive any treatment except counselling and instructions for masticatory muscle exercises which were given also to the subjects in the splint group. Outcomes were visual analogue scale (VAS) on facial pain intensity and clinical findings for TMD which were measured at baseline and after 1-month follow-up. The differences in change between the groups were analysed using regression models. Facial pain decreased and most of the clinical TMD findings resolved in both of the groups. The differences in changes in VAS or clinical TMD findings between the groups were not statistically significant. The findings of this study did not show that stabilisation splint treatment in combination with counselling and masticatory muscle exercises has additional benefit in relieving facial pain and increasing the mobility of the mandible than counselling and masticatory muscle exercises alone in a short time-interval.

BACKGROUND: Teaching the principles of scientific research in a comprehensive way is important at medical and dental schools. In many countries medical and dental training is not complete until the candidate has presented a diploma thesis. The objective of this study was to evaluate the nature, quality, publication pattern and visibility of Finnish medical diploma theses. METHODS: A total of 256 diploma theses presented at the University of Oulu from 2001 to 2003 were analysed. Using a standardised questionnaire, we extracted several characteristics from each thesis. We used the name of the student to assess whether the thesis resulted in a scientific publication indexed in medical article databases. The number of citations received by each published thesis was also recorded. RESULTS: A high proportion of the theses (69.5%) were essentially statistical in character, often combined with an extensive literature review or the development of a laboratory method. Most of them were supervised by clinical departments (55.9%). Only 61 theses (23.8%) had been published in indexed scientific journals. Theses in the fields of biomedicine and diagnostics were published in more widely cited journals. The median number of citations received per year was 2.7 and the range from 0 to 14.7. CONCLUSION: The theses were seldom written according to the principles of scientific communication and the proportion of actually published was small. The visibility of these theses and their dissemination to the scientific community should be improved.