Asja Čelebić

Confirmatory factor analysis of the Oral Health Impact Profile.

Previous exploratory analyses suggest that the Oral Health Impact Profile (OHIP) consists of four correlated dimensions and that individual differences in OHIP total scores reflect an underlying higher-order factor. The aim of this report is to corroborate these findings in the Dimensions of Oral Health-Related Quality of Life (DOQ) Project, an international study of general population subjects and prosthodontic patients. Using the projects Validation Sample (n = 5022), we conducted confirmatory factor analyses in a sample of 4993 subjects with sufficiently complete data. In particular, we compared the psychometric performance of three models: a unidimensional model, a four-factor model and a bifactor model that included one general factor and four group factors. Using model-fit criteria and factor interpretability as guides, the four-factor model was deemed best in terms of strong item loadings, model fit (RMSEA = 0·05, CFI = 0·99) and interpretability. These results corroborate our previous findings that four highly correlated factors - which we have named Oral Function, Oro-facial Pain, Oro-facial Appearance and Psychosocial Impact - can be reliably extracted from the OHIP item pool. However, the good fit of the unidimensional model and the high interfactor correlations in the four-factor solution suggest that OHRQoL can also be sufficiently described with one score.

Clinical bone densitometric evaluation of the mandible in removable denture wearers dependent on the morphology of the mandibular cortex

STATEMENT OF PROBLEM Wide normal variations have been found in the structure and density of the human skeleton, as well as of the mandible. PURPOSE The objective of this study was to determine whether the mandibular bone mineral density is correlated with the classification of the structure of the inferior cortex on panoramic radiographs in complete and removable partial denture wearers. MATERIALS AND METHODS The mandibular cortical index of 136 randomly selected complete and removable partial denture wearers was evaluated via panoramic radiographs. The criteria for the mandibular cortical index were as follow: category 1, sharp endosteal margin of the inferior cortex; category 2, semilunar defects; and category 3, thick cortical residues on endosteal margin. Forty male patients (mean age 72.7; range 56 to 84 years) and 96 female patients (mean age 69.7; range 48 to 86 years) participated. With a copper stepwedge and DenEx 2001 computer program, the mandibular bone mineral density was investigated densitometrically on dental panoramic radiographs. Four experienced observers and 6 general dental practitioners made the observations on all panoramic radiographs. All bone mineral density values were expressed in equivalents of the actual stepwedge thickness. An independent t test (alpha =.05) was used. RESULTS The severity of changes in the mandibular cortex was significantly related to all measured mandibular bone mineral density values (t test: P<.01). Mandibular cortical index category 3 had significantly lower bone mineral density values in all measured regions of interest. Interobserver and intraobserver agreement in mandibular cortical index assessment was excellent. CONCLUSION Patients having lower bone mineral density values in the mandible have much more porous cortical layer of the inferior border of the mandible.

Factor analyses of the Oral Health Impact Profile – Overview and studied population

PURPOSE A desideratum of oral health-related quality of life (OHRQoL) instruments - such as the Oral Health Impact Profile (OHIP) - is that they accurately reflect the structure of the measured construct(s). With this goal in mind, the Dimensions of Oral Health-Related Quality of Life (DOQ) Project was proposed to investigate the number and nature of OHRQoL dimensions measured by OHIP. In this report, we describe our aggregate data set for the factor analyses in the project, which consists of responses to the 49-item OHIP from general population subjects and prosthodontics patients from 6 countries, including a large age range of adult subjects and both genders. MATERIALS AND METHODS The DOQ Projects aggregate data set combines data from 35 individual studies conducted in Croatia, Germany, Hungary, Japan, Slovenia, and Sweden. RESULTS The combined data set includes 10778 OHIPs from 9348 individuals (N=6349 general population subjects, N=2999 prosthodontic patients). To elucidate the OHIP latent structure, the aggregated data were split into a Learning Sample (N=5173) for exploratory analyses and a Validation Sample (N=5022) for confirmatory analyses. Additional data (N=583) were assigned to a third data set. CONCLUSION The Dimensions of Oral Health-Related Quality of Life Project contains a large amount of international data and is representative of populations where OHIP is intended to be used. It is well-suited to assess the dimensionality of the questionnaire.

Colour discrimination of dental professionals and colour deficient laypersons.

OBJECTIVES The aim of the present study was to compare results of non-dental (conventional) and dental colour discrimination tests (customized, shade guide test), to evaluate influence of profession, gender and age of colour normal dentists and laboratory technicians on colour discrimination results and to evaluate results of colour deficient laypersons. METHODS A total of 36 colour normal dental professionals, all volunteers were divided into two groups consisting of 18 participants each: dentists (DDS) and laboratory technicians (CDT). In addition, a group 15 colour deficient males also volunteered (CDP). Colour discrimination was examined using Farnsworth-Munsell 100 Hue Test and total error scores (TES) were calculated. Participants performed a dentistry related colour discrimination test by matching 26 pairs of shade tabs. Shade guide scores (3DS) were calculated. These tests were performed under the controlled conditions of a viewing booth. Mean values and standard deviations were determined. ANOVA, Mann-Whitney test, t-test and Pearsons correlation coefficient (r) were used for result analysis. RESULTS TES and 3DS were correlated for colour normal observers, r = 0.47 (p < 0.01). No statistically significant differences in TES and 3DS by profession, gender and age were recorded. TES of 159 (83) and 3DS of 6.7 (2.7) were recorded for colour deficient laypersons. Based on TES, 33% of colour deficient laypersons had average discrimination, whilst 67% had low discrimination. CONCLUSIONS Within the limitation of this study, it was concluded that results of non-dental and dental colour discrimination tests were correlated, and that profession (DDS/CDT), gender and age gender did not influence colour discrimination of colour normal participants. CLINICAL SIGNIFICANCE Although colour and appearance of dental restorations are of paramount importance for the aesthetic outcome, colour vision of dental professionals is not routinely tested. This paper validates and recommends the usage of dental shade guides for a simple, affordable and understandable testing of colour vision, either as a sole test or complementing conventional (professional) tests.

Comparison of mandibular bone density and radiomorphometric indices in wearers of complete or removable partial dentures

ObjectivesTo examine bone mineral density (BMD) and linear radiomorphometric parameters of the mandible in elderly patients with different types of dentures.MethodsPatients had mandibular complete dentures (CDs) or Kennedy Class I removable partial dentures (RPDs) in the mandible; all patients had CDs in the maxilla. The age and sex distributions of patients with CDs and of those with RPDs were not significantly different. Three parameters were measured in dental panoramic radiographs (DPRs) from a total of 136 patients: thicknesses of the mandibular cortex below the mental foramen, the antegonion, and the gonion. Mandibular BMD was measured densitometrically using DPRs and a copper step wedge. All BMD values were expressed relative to the step wedge thickness.ResultsThere was a significant difference between patients with CDs and those with RPDs for all the radiomorphometric indices measured (P < 0.001); specifically, radiomorphometric indices were higher in RPD wearers. Mandibular BMD values in RPD wearers were higher than those of patients with CDs, and BMD was significantly higher under the saddle in RPD wearers (P < 0.05).ConclusionsThese results support the hypothesis that occlusal forces that are transmitted directly to the mucosa beneath mucosa-borne dentures may cause overloading, which may cause bone resorption; by contrast, under tooth and mucosa-borne dentures, occlusal forces are transmitted not only to mucosa but also to the periodontal ligament of the abutment teeth, thereby reducing the transmission of force to the mucosa, which prevents overload. Greater chewing forces might thus be achieved with tooth and mucosa-borne dentures, which may stimulate bone growth at the mandibular cortex.

Residual ridge atrophy in complete denture wearers and relationship with densitometric values of a cervical spine: a hierarchical regression analysis

BACKGROUND The rate of residual ridge atrophy (RRR) and its association with mineral density of other bones have not yet been fully explained. OBJECTIVE To measure RRR over a 5-year period in complete denture wearers and relate it to the density of a cervical spine (CSBD). MATERIALS AND METHODS Sixty-two patients (different gender, age, body mass index, duration of edentulousness (DE) and different denture-wearing habits) participated. A copper stepwedge was attached to the cassette, and 50 lateral radiograms met the criteria to be included. RESULTS A significant decrease in vertical height was observed in all measured sites. The amount of RRR was highest in frontal areas of both jaws and decreased gradually towards lateral regions. Hierarchical regression analysis revealed that the amount of RRR in the maxillary frontal area could be explained up to 48.4% by the variable DE and only up to 6.1% by the CSBD, while gender had almost no influence (1%). Similar results were obtained for the lateral maxillary RRR (33.9%; 7%; 2%), frontal mandibular RRR (40; 8.4; 0.4%) and lateral mandibular RRR (31.5%; 3.4%; 7.7%). CONCLUSION Skeletal bone density, reflecting systemic and hereditary factors, is weakly related to RRR (3.4-8.4%).

Oral Health-Related Quality of Life in Different Types of Mandibular Implant Overdentures in Function Longer Than 3 Years.

PURPOSE The aim of this study was to evaluate the oral health-related quality of life (OHRQoL) of patients treated with three different types of mandibular implant overdentures (IOD) after at least 3 years in function. MATERIALS AND METHODS A total of 122 patients treated with mini implant (50), locator (56), or bar (16) mandibular IODs participated. Modified plaque (PI) and gingival (GI) indices were also assessed. RESULTS Older patients and patients with mini mandibular IODs were the most satisfied with their OHRQoL. The bar overdenture presented the worst PI and GI results. CONCLUSION The mini mandibular overdenture patients were assessed with a better OHRQoL than those with bar and locator IODs.

Thermographic monitoring of wound healing and oral health-related quality of life in patients treated with laser (aPDT) after impacted mandibular third molar removal

The objective of this study was to assess the impact of low-level laser therapy on wound swelling, wound temperature changes, and oral health-related quality of life (OHRQoL) after surgical removal of impacted lower third molars. Forty patients with impacted lower third molars requiring surgical removal participated in this study; all were Pell-Gregory class IIB or IIC. The patients were divided randomly into two groups for post-extraction therapy. One group received antimicrobial photodynamic therapy (aPDT) and the other received no additional therapy (placebo group). Temperature measurements were done using an infrared thermographic camera on days 3 and 7 postoperative. OHRQoL was assessed in both groups on day 7 using the Oral Health Impact Profile questionnaire translated into Croatian (OHIP-14-CRO). Prior to surgical treatment, there was no difference in patient characteristics between the two groups. A significantly lower temperature and less wound swelling were recorded on day 3 postoperative in the aPDT group compared to the control group (P<0.001). Participants in the aPDT group also had significantly lower OHIP-14-CRO summary scores (P<0.01). The present study showed beneficial effects of the aPDT modality of low-level laser therapy: postoperative wound swelling was reduced and wound temperature decreased, and OHRQoL was better through the 7-day postoperative period in comparison to the placebo group.

Longitudinal measurement invariance in prospective oral health-related quality of life assessment

BackgroundProspective assessments of oral health-related quality of life (OHRQoL) changes are prone to response shift effects when patients reconceptualize, reprioritize, or recalibrate the perceived meanings of OHRQoL test items. If this occurs, OHRQoL measurements are not “invariant” and may reflect changes in problem profiles or perceptions of OHRQoL test items. This suggests that response shift effects must be measured and controlled to achieve valid prospective OHRQoL measurement. The aim of this study was to quantify response shift effects of Oral Health Impact Profile (OHIP) scores in prospective studies of prosthodontic patients.MethodsData came from the Dimensions of Oral Health-Related Quality of Life Project. The final sample included 554 patients who completed the OHIP questionnaire on two occasions: pre- and post-treatment. Only items that compose the 14-item OHIP were analyzed. Structural equation models that included pre- and post-treatment latent factors of OHRQoL with different across-occasion constraints for factor loadings, intercepts, and residual variances were fit to the data using confirmatory factor analysis.ResultsData fit both the unconstrained model (RMSEA = .038, SRMR = .051, CFI = .92, TLI = .91) and the partially constrained model with freed residual variances (RMSEA = .037, SRMR = .064, CFI = .92, TLI = .92) well, meaning that the data are well approximated by a one-factor model at each occasion, and suggesting strong factorial across-occasion measurement invariance.ConclusionsThe results provided cogent evidence for the absence of response shift in single factor OHIP models, indicating that longitudinal OHIP assessments of OHRQoL measure similar constructs across occasions.

Morphology of Co–Cr–Mo dental alloy surfaces polished by three different mechanical procedures

The present study aims at characterizing the three‐dimensional (3‐D) morphology of a Co–Cr–Mo dental alloy surface as a result of three different procedures used for polishing it. The sample surface morphology of the sampled surface was examined employing atomic force microscopy (AFM), statistical surface roughness parameters, and fractal analysis. An extra‐hard dental alloy of cobalt–chromium–molybdenum (Co–Cr–Mo) (Wironit®, from BEGO, Bremen, Germany) was prepared and moulded. Different polishing treatments were carried out on three groups of six samples each—a total of 18 samples. The first group contained six electropolished (EP) samples. The second group containing six samples went through a mechanical polishing process employing green rubber discs and a high shine polishing paste applied by a rotating black brush (BB). The third group comprising six samples as well went through a mechanical polishing process by means of green rubber discs, high shine polishing paste, and a rotating deer leather brush (DL). Fractal analysis on the basis of a computational algorithm applied to the AFM data was employed for the 3‐D quantitative characterization of the morphology of the sampled surfaces. The fractal dimension D (average ± standard deviation) of 3‐D surfaces for BB samples (2.19 ± 0.07) is lower than that of the DL samples (2.24 ± 0.08), which is still lower than that of the EP samples (2.27 ± 0.09). The results indicated the BB samples as presenting the lowest values of statistical surface roughness parameters, thus the best surface finish, while the EP samples yielded the highest values. Microsc. Res. Tech. 78:831–839, 2015.