Strana 978 VOJNOSANITETSKI PREGLED ORIGINAL ARTICLE Vojnosanit Pregl 2012; 69(11): 978–985. UDC: 616.314-08 DOI: 10.2298/VSP111027026G Factors influencing a patient's decision to choose the type of treatment to improve dental esthetics Faktori koji utiþu na pacijentov izbor terapije za poboljšanje estetike zuba Renata Gržiü*, Stjepan Špalj†, Vlatka Lajnert*, Snježana Glaviþiü‡, Ivone Uhaþ*, Daniela Kovaþeviü Paviþiü* *Department of Prosthodontics, †Department of Paediatric Dentistry and Orthodontics, ‡ Department of Endodontics and Restorative Dentistry, School of Medicine, University of Rijeka, Rijeka, Croatia Abstract Background/Aim. Interest in dental esthetics has increased rapidly during the last few decades among both patients and dentists, and the creation of a natural dental appearance has become an important task in all fields of dentistry, especially in prosthodontics and restorative dentistry. The aim of this research was to investigate factors influencing a patient's decision to choose the type of treatment to improve dental esthetics. Methods. A total of 700 Caucasian subjects participated in the crosssectional study (261 men, 439 women, aged 18–86 years, mean age 46.2 ± 18.6). The study included clinical examination and a self-administrated questionnaire based on self-perceived esthetics, satisfaction with the appearance of their maxillary anterior teeth and previous dental experience. Multiple logistic regression was used in statistical analysis. Results. Hiding teeth during smile was the most important predictor for choosing fixed prosthetic restorations (OR 9.1), followed by self-perceived bad fixed prosthesis, malpositioned teeth and female gender (OR 2.9, 2.4, and 1.5, respectively). The increase in satisfaction Apstrakt Uvod/Cilj. U poslednjih nekoliko decenija znaÿajno se poveýava interesovanje za dentalnu estetiku kako ispitanika tako i stomatologa. Postizanje prirodnog izgleda je važan zadatak u svim poljima stomatologije, naroÿito protetike i restorativne stomatoglogije. Cilj ovog istraživanja bio je da se utvrdi koji faktori utiÿu na izbor terapije za poboljšanje zubne estetike kod ispitanika. Metode. Istraživanjem je bilo obuhvaýeno 700 ispitanika (261 muškarac, 439 žena, proseÿne starosti 46,2 ± 18,6 godina, srednje godine 45). Istraživanje je bilo zasnovano na kliniÿkom pregledu i ispunjavanju upitnika koji je ukljuÿivao pitanja zasnovana na samoproceni zadovoljstva pojavnošýu gornjih prednjih zuba, te prethodnim dentalnim iskustvima. U with dental appearance and previous orthodontic therapy reduced chances for seeking prosthetic therapy (each OR 0.4). The significant predictors for bleaching choosing were hiding teeth during smiling, already done bleaching, female gender, lower levels of satisfaction with dental appearance and the absence of the previous orthodontic therapy (OR 5.8, 2.4, 1.8, 0.5 and 0.4, respecitively). Hiding teeth during smile, self-perceived malposition and crowding, and lower levels of satisfaction, were significant predictors for choosing orthodontic treatment (OR 3.1, 2.4, 2.2 and 0.6, respectively). None of current dental statuses was statistically significant predictor for choosing prosthodontic, bleeching nor orthodontic therapy. Conclusion. The psychological elements and female gender are the main predictors of seeking dental therapy. Understanding the prevalence of dissatisfaction with the present esthetics and desired treatments to improve esthetics can be a guide for strategies for intervention to improve esthetics. Key words: patient satisfaction; esthetics, dental; crowns; tooth bleaching; orthodonics. statistiÿkoj obradi podataka korišýena je multipla logistiÿka regresija. Rezultati. Skrivanje zuba tokom smejanja je najvažniji prediktor za izbor fiksnih protetskih nadomestaka (OR 9.1), potom loše percipirani fiksni protetski nadomesci, loše pozicionirani zubi, te ženski pol (OR 2.9, 2.4, i 1.5 respektivno). Poveýanje zadovoljstva dentalnom estetikom i prethodna ortodontska terapija smanjuju šansu za traženjem protetske terapije (svaki OR 0.4). Znaÿajni prediktori za traženje postupka izbeljivanja zuba su: skrivanje zuba tokom smejanja, prethodni postupak izbeljivanja, ženski pol, niže razine zadovoljstva dentalnom estetikom, te odsutnost prethodne ortodontske terapije (OR 5.8, 2.4, 1.8, 0.5 i 0.4 respektivno). Skrivanje zuba tokom osmeha, samopercipirani loše pozicionirani i zbijeni zubi te niža razina zadovoljstva dentalnom estetikom bili su prediktori tra- Correspondence to: Renata Gržiý, University of Rijeka, School of Medicine, Krešimirova 40, 51 000 Rijeka, Croatia. Phone: +385 91 165 12 13. E-mail: renata.grzic@medri.hr Volumen 69, Broj 11 VOJNOSANITETSKI PREGLED ženja ortodontske terapije (OR 3.1, 2.4, 2.2 i 0.6 respektivno). Niti jedan od postojeýih dentalnih statusa nije bio znaÿajan prediktor traženja protetske terapije, izbeljivanja ili ortodontske terapije. Zakljuÿak. Psihološki elementi i ženski pol glavni su prediktori traženja dentalne terapije. Razumevanje prevalencije nezadovoljstva dentalnom este- Introduction Aesthetics is a primary consideration for patients seeking both orthodontic and prosthodontic treatment 1, 2. Interest in dental esthetics has increased rapidly during the last few decades among both patients and dentists, and the creation of a natural dental appearance has become an important task in all fields of dentistry, especially in prosthodontics and restorative dentistry 3. The development of new techniques and dental material has led to a higher number of therapeutic options and consequently to an attractive outcome 1. Numerous factors are related to dental aesthetic, such as the color, shape and position of teeth and the shape of dental arch. These factors are affected by individual preferences, cultural and sociodemographic factors. The viewer's perception of visual experience could be pleasant and beautiful by one individual and culture, while it could be seen as unpleasant in another 4, 5. Perception of tooth appearance could be influenced by gender, age and education level. Females are reported to be more sensitive than males to the appearance of teeth and the importance of teeth for quality of life decreases with ageing and higher education levels 6. Previous dental treatments of anterior teeth also have an impact on dental aesthetic, which is affected by individual preferences and cultures. Unfortunately, in some cases, dentists may develop an aesthetic appearance differing from the patient's concepts, resulting in communication problems and unanticipated difficulties 7. Nowadays, cosmetic dentistry has become an important aspect of dentistry. Tooth whitening treatments, anterior teeth restoration, labial veneers crowns, and orthodontic treatment are frequently demanded by patients who are interested in improving their dental appearance 8. Factors that influence patients' decision regarding the choice of a particular type of therapy to improve dental aesthetics are still insufficiently explored. Therefore, the aim of this study was to investigate the predictors influencing a patient's decision to choose prosthetic, orthodontic or bleeching type of treatment to improve dental aesthetics in maxillary anterior region in general population. It was hypothesized that significant predictors are age, gender, educational level, previous dental treatment and self-perceived dental appearance. Older subjects, females, higher educated and less satisfied with their dental appearance could be more prone to seeking crowns in maxillary anterior teeth. We assumed that subjects who want bleaching more often hide teeth during smiling, are dissatisfied with dental appearance and are more often females. Orthodontic therapy will probably choose subjects with self-perceived malpositioned and crowded teeth who are more prone to hide their teeth during smiling. Gržiý R, et al. Vojnosanit Pregl 2012; 69(11): 978–985. Strana 979 tikom i željenih tretmana za poboljšanje iste glavni su vodiÿi strategije za njeno poboljšanje. Kljuÿne reÿi: bolesnik, zadovoljstvo; zub, estetika; ortodoncija; zub, kruna; zub, beljenje. Methods A total of 700 Caucasian subjects from Rijeka region, Croatia participated in the cross-sectional study (261 men, 439 women, mean age 46.2 ± 18.6 age, median 45 years). Sampling procedure included a convenient sample – consecutive voluntary blood donors in the Department of Transfusion Medicine, University Hospital Rijeka, subjects at the regular annual check-ups in the Institute for Public Health Rijeka, and patients seeking treatment in the University Dental Clinic Rijeka. All the participants included in the study gave written informed consent to the survey procedures, which were approved by the Ethical Committee of the Rijeka University School of Medicine. The study included clinical examination and a questionnaire. Inclusion criterion was to have all six anterior teeth present in the upper jaw; while exclusion criteria were the evidence of gingival inflammation or gingival hyperplasia, observable gingival recession, observable occlusal wear, participants without active orthodontic therapy by edgewise appliances, participants with temporary crowns in prosthetic rehabilitation, participants in progressive endodontic therapy, participants with splints for treatment of temporomandibular disorders and participants without craniofacial syndromes. The questionnaire was self-administrated and the included questions were based on: self-assessed satisfaction with dental appearance of their maxillary anterior teeth using a three-point scale with possible answers 'dissatisfied', 'moderately satisfied', or 'completely satisfied'. Data on gender, age, educational level and self-reported previous therapy – orthodontic, bleaching, implants, crowns, root canal therapy, root scaling, professional teeth cleaning (dichotomised 0 = absent, 1 = present) were also included. Selfperceived dental appearance included questions on: crowded, malpositioned, protruded, decayed, fractured teeth and bad fixed teeth prosthesis (dichotomised 0 = absent, 1 = present). Clinical examination included assessment of dental status of six maxillary anterior teeth using classification: natural teeth without dental treatment, composite fillings, metal ceramic crowns and ceramic crowns / veneers. The data were analyzed using SPSS 10.0 statistical software package (SPSS 10.0; SPSS Inc., Chicago, IL, USA). The Chi-square test, t-test and Fischer exact test were used to compare differences between population choosing and refusing prosthetics, orthodontic or bleeching. Eta Squred and Cramer's V were used to estimate the size of the effect, that is, the share of total variability of dependent variable explained by the factor tested. Multiple logistic regression analysis was used to explore the significance of predictors of choosing the type of treatment for improvement of aesthetics in maxillary anterior region with 95% confidence Strana 980 VOJNOSANITETSKI PREGLED intervals given for the odds ratios, indicating statistically significant relationships if both values were either greater or lesser than 1. The significance of the effects in the logistic regression model was performed via the Wald statistics and likelihood ratio test with chi-square statistics. A statistical significance was preset at p < 0.05. Volumen 69, Broj 11 Results The results of univariate analysis considering choosing crowns for improvement of dental aesthetics are presented in Table 1. To identify predictors for choosing crowns while controlling for other variables in multivariate analysis, two Table 1 Differences in variables between choosing and non-choosing crowns population Variables Age (ʉ ± SD)*, years Gender**, n (%) m f Education level**, n (%) primary / secondary college / university Satisfaction with dental appearance* crowded teeth**, n (%) no yes Malpositioned teeth**, n (%) no yes Protrused teeth**, n (%) no yes Decayed teeth**, n (%) no yes Bad prosthesis**, n (%) no yes Fractured teeth, n (%) no yes Hide teeth during smile**, n (%) no yes Orthodontic th.**, n (%) no yes Bleaching th.**, n (%) no yes Crowns**, n (%) no yes Implants**, n (%) no yes Root canal th.**, n (%) no yes Professional teeth cleaning**, n (%) ne da Root scaling**, n (%) no yes Status MOD***, n (%) without therapy composite filling metal acrylic crowns ceramic crowns/veneers Seeking crowns No (n = 308) Yes (n = 392) 43.63 ± 18.52 48.24±18.35 Significance Effect size 0.001 0.015 120 (46%) 188 (42.8%) 141 (54%) 251 (57.2%) 0.432 0.001 232 (42.6%) 76 (49%) 2.52 ± 0.58 313 (57.4%) 79 (51%) 1.92 ± 0.78 0.153 < 0.001 0.003 0.154 248 (46.9%) 57 (34.8%) 281 (53.1%) 107 (65.2%) 0.007 0.011 259 (49.6%) 48 (27.1%) 263 (50.4%) 129 (72.9%) < 0.001 0.039 258 (45.5%) 49 (37.1%) 309 (54.5%) 83 (62.9%) 0.098 0.004 297 (45.7%) 10 (20.4%) 353 (54.3%) 39 (79.6%) < 0.001 0.017 301 (47.8%) 6 (8.7%) 329 (52.2%) 63 (91.3%) < 0.001 0.055 277 (46.6%) 31 (29.2%) 317 (53.4%) 75 (70.8%) < 0.001 0.016 305 (49.3%) 3 (3.8%) 314 (50.7%) 76 (96.2%) < 0.001 0.084 225 (40.3%) 83 (58.5%) 333 (59.7%) 59 (41.5%) < 0.001 0.022 276 (43.7%) 32 (46.4%) 355 (56.3%) 37 (53.6%) 0.703 0.000 240 (50.3%) 68 (30.6%) 237 (49.7%) 154 (69.4%) <0.001 0.034 297 (43.4%) 11 (73.3%) 388 (56.6%) 4 (26.7%) 0.032 0.008 217 (54.3%) 91 (30.3%) 183 (45.8%) 209 (69.7%) < 0.001 0.057 86 (49.4%) 222 (42.2%) 88 (50.6%) 304 (57.8%) 0.113 0.004 268 (44.9%) 40 (38.8%) 329 (55.1%) 63 (61.2%) 0.283 0.002 205 (49.5%) 29 (33.7%) 33 (32%) 41 (42.3%) 209 (50.5%) 57 (66.3%) 70 (68%) 56 (57.7%) 0.002 0.021 *t-test and partial eta squared for effect size; **Fischer exact test and Cramer's V for effect size; ***Ȥ2-test Cramer's V for effect size. Gržiý R, et al. Vojnosanit Pregl 2012; 69(11): 978–985. Volumen 69, Broj 11 VOJNOSANITETSKI PREGLED logistic regression models were used. First logistic regression model used age, gender, education level and current satisfaction with dental appearance for prediction of seeking prosthetic restoration. Choosing prosthetic solution was significantly related to advanced age and decreased satisfaction with personal dental appearance producing OR 1.02 and 0.29, respectively (p < 0.001) (Table 2). This model correctly classified 66.1% of population. Strana 981 hiding teeth during smiling, already done bleaching and female gender who increase the chance for seeking bleaching for 5.8, 2.4 and 1.8 times. Searching for bleaching was associated with lower levels of satisfaction with appearance of the teeth and the absence of the previous orthodontic therapy (OR 0.5 and 0.4, respectively; Table 4). The results of univariate analysis considering orthodontics are presented in Table 5. In multivariate logistic regression model the smallTable 2 Logistic regression models for predicting variables influencing crowns choosing Variables Constant (Model 1)* Age Gender (female) Educational level (higher) Satisfaction with dental appearance Constant (Model 2)**† Age Gender (female) Satisfaction with dental appearance Previous orthodontic th Perceived malposition Perceived bad fixed prosthesis Hide teeth during smiling B 2.013 0.019 0.302 -0.291 -1.235 0.961 0.013 0.416 -0.923 -1.028 0.862 1.066 2.209 SE 0.364 0.005 0.177 0.200 0.124 0.580 0.006 0.195 0.145 0.260 0.284 0.499 0.625 Wald 30.581 16.128 2.918 2.110 99.150 2.745 5.275 4.521 40.351 15.675 9.183 4.561 12.505 Sig. < 0.001 < 0.001 0.088 0.146 < 0.001 0.098 0.022 0.033 < 0.001 < 0.001 0.002 0.033 < 0.001 OR 95% CI 1.019 1.352 0.748 0.291 1.010–1.028 0.956–1.912 0.505–1.107 0.228–0.371 1.013 1.515 0.397 0.358 2.367 2.903 9.104 1.002–1.024 1.033–2.222 0.299–0.528 0.215–0.595 1.356–4.132 1.092–7.718 2.677–30.967 *Negelkerke Pseudo R2 = 0.235; 66.1%; p < 0.001. **Negelkerke Pseudo r2 = 0.366, 73.5%, p < 0.001. †Only statistically significant variables are listed. In the second model variable concerning previous dental therapy, perceived altered dental aesthetics and current dental status were added. For current dental status on maxillary anterior teeth most common restorative solution characteristics were used (mod value). Controlling all other variables in the model the significant predictors for seeking crowns in the maxillary anterior region are: age, female gender, satisfaction with dental appearance, previous orthodontic therapy, perceived malpositioned teeth, perceived bad fixed prosthesis and hiding teeth during smile. Hiding teeth during smile is the most important predictor producing 9.1 fold higher chance respectively for seeking the crowns (OR = 9.1 (95% CI 2.7 – 31.0)) (Table 2). Selfperceived bad fixed prosthesis, malpositioned teeth and female gender produced 2.9, 2.4, and 1.5 fold higher chance respectively, that participants want prosthetic therapy. Advanced age was statistically significant associated with seeking crowns (p = 0.022), but odds ratio was very low (OR = 1.02) (Table 2). The increase in satisfaction with dental appearance and previous orthodontic therapy reduced chances for seeking prosthetic therapy with odds ratios (each OR = 0.4) (Table 2). Addition of current dental status as a predictor in a model of logistic regression did not statistically significantly contribute to explanation of variability. None of current dental status (own natural maxillary anterior teeth, composite fillings, metal acrylic crowns and porcelain-fused-to ceramic crowns / ceramic veneers) was statistically significant predictor for seeking fixed prosthodontic restauration. The results of univariate analysis considering bleeching are presented in Table 3. In multivariate logistic regression model the significant predictors for seeking bleaching were: Gržiý R, et al. Vojnosanit Pregl 2012; 69(11): 978–985. est numbers of factors had predictive value in seeking orthodontic treatment. In the first model, only the lower satisfaction with the appearance of the teeth was associated with seeking orthodontic treatment (p < 0.001). In the second model, controlling other factors, lower levels of satisfaction, self-perceived crowding, malposition and hiding teeth during smile were significant predictors, producing 2.2, 2.4 and 3.1 times higher chance, respectively, to seek orthodontic treatment (Table 6). Discussion For many years clinicians considered aesthetics to be far less important than function, structure and biology. However, nowdays if a treatment plan do not include a clear view of its aesthetics impact on the patient, the outcome could be disastrous 9. A patient's satisfaction has become an increasingly important factor in dental treatment. Therefore, clinicians should begin a treatment plan with well-defined aesthetics objectives, and then should consider the impact of the planned treatment on function, structure and biology. Such planning requires the clinician to rely on several dental disciplines (namely prosthodontics, periodontics and orthodontics) to deliver the most comprehensive level of dental care to a patient 8. Therefore, we investigated factors influencing people’s decision to choose the type of treatment to improve dental aesthetics. We hypothesised that older subject would prefer prosthetic restoration and younger ones bleaching and orthodontics and that females would be more prone to every type of dental treatment than males. Searching for dental therapy is probably under strong influence of previous dental therapy Strana 982 VOJNOSANITETSKI PREGLED Volumen 69, Broj 11 Table 3 Differences in variables between bleaching seeking and non-seeking population Seeking bleeching Variables Significance No (n = 258) Yes (n = 442) Age (ʉ ± SD)*, years 45.28 ± 18.68 46.75 ± 18.48 0.313 Gender**, n (%) m 109 (41.8%) 152 (58.2%) f 149 (33.9%) 290 (66.1%) 0.043 Education level**, n (%) primary / secondary 204 (37.4%) 341 (62.6%) college / university 54 (34.8%) 101 (65.2%) 0.573 Satisfaction with dental appearance*, 2.53 ± 0.58 1.98 ± 0.78 < 0.001 ʉ ± SD Crowded teeth**, n (%) no 206 (38.9%) 323 (61.1%) yes 50 (30.5%) 114 (69.5%) 0.052 Malpositioned teeth**, n (%) no 214 (41.0%) 408 (59.0%) yes 44 (24.9%) 133 (75.1%) < 0.001 Protruded teeth**, n (%) no 220 (38.8%) 347 (61.2%) yes 38 (28.8%) 94 (71.2%) 0.035 Decayed teeth**, n (%) no 248 (38.2%) 402 (61.8%) yes 10 (20.4%) 39 (79.6%) 0.014 Bad prosthesis**, n (%) no 248 (39.4%) 382 (60.6%) yes 10 (14.5%) 59 (85.5%) < 0.001 Fractured teeth, n (%) no 234 (39.4%) 360 (60.6%) yes 24 (22.6%) 82 (77.4%) < 0.001 Hide teeth during smile**, n (%) no 254 (41.0%) 365 (59.0%) yes 4 (5.1%) 75 (94.9%) < 0.001 Orthodontic th.**, n (%) no 195 (34.9%) 363 (65.1%) yes 63 (44.4%) 79 (55.6%) 0.041 Bleaching th.**, n (%) no 241 (38.2%) 390 (61.8%) yes 17 (24.6%) 52 (75.4%) 0.026 Crowns**, n (%) no 184 (38.6%) 293 (61.4%) yes 74 (33.3%) 148 (66.7%) 0.207 Implants**, n (%) no 248 (36.2%) 437 (63.8%) yes 10 (66.7%) 5 (33.3%) 0.027 Root canal th.** , n (%) no 171 (42.8%) 229 (57.3%) yes 87 (29.0%) 213 (71.0%) < 0.001 Professional teeth cleaning**, n (%) no 73 (42.0%) 101 (58.0%) yes 185 (35.2%) 341 (64.8%) 0.123 Root scaling**, n (%) no 222 (37.2%) 375 (62.8%) yes 36 (35.0%) 67 (65.0%) 0.740 Status MOD***, n (%) without therapy 155 (37.4%) 259 (62.6%) composite filling 26 (30.2%) 60 (69.8%) metal acrylic crowns 36 (35.0%) 67 (65.0%) ceramic crowns/veneers 41 (42.3%) 56 (57.7%) 0.382 Effect size 0.001 0.006 < 0.001 0.125 0.006 0.021 0.007 0.009 0.024 0.015 0.056 0.006 0.007 0.003 0.008 0.020 0.004 < 0.001 0.004 *t-test and eta squared for effect size; **Fischer exact test and Cramer's V for effect size; *** Ȥ2-test Cramer's V for effect size. Table 4 Logistic regression models for predicting variables influencing bleaching seeking Variables B SE Wald Sig. OR Constant (Model 1)* 2.566 0.409 39.304 0.000 Age 0.008 0.005 2.724 0.099 1.008 Gender (female) 0.499 0.178 7.864 0.005 1.646 Education level (higher) -0.174 0.206 0.707 0.400 0.841 Satisfaction with dental appearance -1.129 0.125 80.963 0.000 0.323 Constant (Model 2)**† 1.603 0.574 7.805 0.005 Gender (female) 0.560 0.188 8.843 0.003 1.750 Satisfaction with dental appearance -0.937 0.145 41.989 0.000 0.392 Previous orthodontic th -0.681 0.243 7.886 0.005 0.506 Previous bleaching 0.878 0.336 6.840 0.009 2.405 Hide teeth during smiling 1.755 0.547 10.289 0.001 5.784 95% CI 0.999–1.017 1.162–2.333 0.561–1.260 0.253–0.414 1.210–2.531 0.295–0.520 0.314–0.814 1.246–4.643 1.979–16.901 *Negelkerke Pseudo R2 = 0.189, 64.7%, p < 0.001; **Negelkerke Pseudo R2 = 0.265, 68%, p < 0.001; †Only statistically significant variables are listed. Gržiý R, et al. Vojnosanit Pregl 2012; 69(11): 978–985. Volumen 69, Broj 11 VOJNOSANITETSKI PREGLED Strana 983 Table 5 Differences in variables between orthodontic therapy seeking and non-seeking population Seeking orthodontics Variables Significance Effect size No (n = 308) Yes (n = 392) Age (ʉ ± SD)*, years 46.89 ± 18.42 45.68 ±18.66 0.393 0.001 Gender**, n (%) m 120 (46.0%) 141 (54.0%) f 188 (42.8%) 251 (57.2%) 0.432 0.001 Education level**, n (%) primary / secondary 241 (44.2%) 304 (55.8%) college / university 67 (43.2%) 88 (56.8%) 0.855 < 0.001 Satisfaction with dental appearance*, 2.44 ± 0.65 1.97 ± 0.78 < 0.001 0.094 ʉ ± SD Crowded teeth**, n (%) no 269 (50.9%) 260 (49.1%) yes 34 (20.7%) 130 (79.3%) < 0.001 0.067 Malpositioned teeth**, n (%) no 271 (51.9%) 251 (48.1%) yes 36 (20.3%) 141 (79.7%) < 0.001 0.077 Protruded teeth**, n (%) no 267 (47.1%) 300 (52.9%) yes 40 (30.3%) 92 (69.7%) < 0.001 0.017 Decayed teeth**, n (%) no 293 (45.1%) 357 (54.9%) yes 14 (28.6%) 35 (71.4%) 0.026 0.007 Bad prosthesis**, n (%) no 285 (45.2%) 345 (54.8%) yes 22 (31.9%) 47 (68.1%) 0.040 0.006 Fractured teeth, n (%) no 273 (46.0%) 321 (54.0%) yes 35 (33.0%) 71 (67.0%) 0.015 0.009 Hide teeth during smile**, n (%) no 297 (48.0%) 322 (52.0%) yes 9 (11.4%) 70 (88.6%) < 0.001 0.055 Orthodontic th.** , n (%) no 242 (43.4%) 316 (56.6%) yes 66 (46.5%) 76 (53.5%) 0.509 0.001 Bleaching th.** , n (%) no 278 (44.1%) 353 (55.9%) yes 30 (43.5%) 39 (56.5%) 1.000 < 0.001 Crowns**, n (%) no 224 (47.0%) 253 (53.0%) yes 83 (37.4%) 139 (62.6%) 0.018 0.008 Implants**, n (%) no 298 (43.5%) 387 (56.5%) yes 10 (66.7%) 5 (33.3%) 0.112 0.005 Root canal th.** , n (%) no 203 (50.8%) 197 (49.3%) yes 105 (35.0%) 195 (65.0%) < 0.001 0.025 Professional teeth cleaning**, n (%) no 77 (44.3%) 97 (55.7%) yes 231 (43.9%) 295 (56.1%) 1.000 < 0.001 Root scaling**, n (%) no 257 (43.0%) 340 (57.0%) yes 51 (49.5%) 52 (50.5%) 0.238 0.002 Status MOD***, n (%) without therapy 185 (44.7%) 229 (55.3%) composite filling 32 (37.2%) 54 (62.8%) metal acrylic crowns 44 (42.7%) 59 (57.3%) ceramic crowns/veneers 47 (48.5%) 50 (51.5%) 0.468 0.004 *t-test and eta squared for effect size; ** Fischer exact test and Cramer's V for effect size; ***Ȥ2-test Cramer's V for effect size. Table 6 Logistic regression models for predicting variables influencing orthodontic therapy seeking Variables B S.E. Wald Sig. OR 95% CI Constant (Model 1)* 2.176 0.352 38.327 < 0.001 Age -0.003 0.004 0.365 0.546 0.997 0.989–1.006 Gender (female) 0.193 0.167 1.326 0.249 1.213 0.873–1.684 Education level (higher) 0.098 0.193 0.258 0.612 1.103 0.755–1.612 Satisfaction with dental appearance -0.881 0.112 61.985 < 0.001 0.415 0.333–0.516 Constant (Model 2)**† 0.753 0.550 1.875 0.171 Satisfaction with dental appearance -0.587 0.134 19.085 < 0.001 0.556 0.427–0.723 Perceived crowding 0.783 0.264 8.774 0.003 2.188 1.303–3.673 Perceived malposition 0.891 0.275 10.476 0.001 2.437 1.421–4.179 Hide teeth during smiling 1.133 0.404 7.871 0.005 3.106 1.407–6.856 *Negelkerke Pseudo R2 = 0.128, 63.5%, p < 0.001; **Negelkerke Pseudo R2 = 0.256, 69.8%, p < 0.001; †Only statistically significant variables are listed. Gržiý R, et al. Vojnosanit Pregl 2012; 69(11): 978–985. Strana 984 VOJNOSANITETSKI PREGLED and psychological elements, namely dissatisfaction with own teeth, hiding teeth during smile and self perceived altered aesthetic. We expected that in older individuals their interest in dental appearance would be diminished, together with the lower socio-economic status of the older patients and their lower incomes (they are not able any more to afford themselves very expensive aesthetic restorations). It seems that older people are more satisfied with their dental appearance than younger 10, 11. But this finding is under strong influence of their dental status – properly made porcelain-fused-to-metal crowns or fixed partial dentures on their upper anterior teeth 11. Still, according to our study none of current dental status (own natural maxillary anterior teeth, composite fillings, metal acrylic crowns and porcelain-fused-to ceramic crowns / ceramic veneers) is a significant predictor for seeking fixed prosthodontic restorations. It is reported that age has an impact on desiring prosthetic restorations 12. This is consistent with data obtained from this study. This research showed that beside age and female gender significant predictors of searching fixed prosthetic restorations are lower satisfaction with dental appearance, self-perceived malpositioned teeth, bad fixed prosthesis and hiding teeth during smile. Age and gender are considered significant factors in predicting the color of the central incisors 13. On the biological point of view it is known that with increasing age central incisors become darker, more reddish and more yellow, which is more pronounced in men than in women. Our study demonstrated that female gender is a significant predictor for choosing bleaching to improve dental aesthetics, but the age is not. It is commonly thought that women are more interested in their appearance than men. Indeed, female patients were found to be more concerned with their dental appearance than males, as well as to be more critical in judging their dental appearance 13. Our study identified lower level of satisfaction with tooth appearance and hiding teeth during smiling as predictors for choosing bleaching to improve altered dental esthetics. It has been reported that 28% of adults in the UK are unsatisfied with the appearance of their teeth and 34 % of adult population in the USA is unsatisfied with their current tooth color 14. In contrast to crowing or veneering whitening of teeth is relatively non-invasive and preserves hard dental tissues, therefore it is the most-desired basic treatment for the improvement of dental aesthetics 15. This could be explained by the fact that most of the patients are dissatisfied with their tooth color and many of them had not made any attempt toward tooth whitening in the past. In addition, a study of 180 female patients in South London 16 showed that whitened teeth were preferred over teeth with original color with the former associated with greater attractiveness. Still, according to our data previous bleaching and the absence of previous orthodontic treatment are significant predictors for choosing bleaching. Probably the patients who underwent the procedure of tooth bleaching want more because they saw that it was relatively easy and painless procedure which is unfortunately reversible. A variety of factors, including socio-economic background, education level, age, gender, self-esteem, self-per- Volumen 69, Broj 11 ceived dental aesthetic, social and cultural norms have been suggested as factors affecting orthodontic treatment motives 2, 17, 18. Females are often more dissatisfied with their teeth than males 12, 14, 18, but it is also reported that there was no significant association between the desire for orthodontic treatment and the variables gender and age 16, which is confirmed by our study. Poor self-perceived aesthetics and better socioeconomic position more significantly influence the decision to seek orthodontic treatment producing odds ratios of 16.7 and 39.1, than severe malocclusion (OR = 3.4) 19. Generally lower satisfaction with dental appearance is the main predictor of desire to undergo orthodontic therapy, according to our research, accompanied with self-perceived crowding, malposition and hiding teeth during smile. It is reported that the main factor associated with orthodontic treatment seeking is self-perception of psychosocial impact of malocclusion, and not to improve altered masticatory function 18. The desire for treatment, concern about dental appearance and oral health related quality of life (OHRQoL) are often interrelated. Malocclusion has modest influence on quality of life 20 that is more evident in altered emotional well-being than in masticatory function or social contacts 2. Still worse OHRQoL produces 3.1 times higher chance to seek orthodontic treatment, although severly compromised aesthetics is a better predictor of worse OHRQoL than seeking orthodontic treatment 21. It appears that satisfaction with personal dental appearance and awareness of malocclusion are better related in persons with no treatment need or minor need than in those with major need 22. Although our study did not find any previous dental treatment as a predictor of desire for orthodontic treatment, it is reported that perception of orthodontic treatment need is higher in previously orthodontically treated subjects 2. It must be kept in mind that the majority of studies concerning orthodontic treatment motives are done in children and adolescents, and not in adult population. Therefore, the results of our study could not be properly related to published data. Since aesthetics has become an important issue in modern society and the number of elective aesthetic procedures increases, it seems important to have a good communication between a patient and the dentist, incorporating individual patients' and professional differences when planning the treatment and try to visualize treatments results before finalization. Conclusion This research indicates that in clinical works we must always consider the following clinical guidelines: females more often want dental treatments, the current dental status does not necessarily affect the choice of desirable dental treatments, but previous dental treatment experience does. Dental treatment to improve dental aesthetics is under strong influence of self-perceived altered aesthetics and the level of dissatisfaction. There are, unfortunately, a very small number of published papers on this issue, therefore further research should be encouraged. Gržiý R, et al. Vojnosanit Pregl 2012; 69(11): 978–985. Volumen 69, Broj 11 VOJNOSANITETSKI PREGLED Strana 985 R E F E R E N C E S 1. Hasanreisoglu U, Berksun S, Aras K, Arslan I. An analysis of maxillary anterior teeth: facial and dental proportions. J Prosthet Dent 2005; 94(6): 530î8. 2. Spalj S, Slaj M, Varga S, Strujic M, Slaj M. Perception of orthodontic treatment need in children and adolescents. Eur J Orthod. 2010 Aug;32(4):387-94. 3. Carlsson GE, Johansson A, Johansson AK, Ordell S, Ekbäck G, Unell L. Attitudes toward dental appearance in 50- and 60Year-old subjects living in Sweden. J Esthet Restor Dent 2008; 20(1): 46î55; discussion 56. 4. Lombardi RE. 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