| Abstract | Cilj: Cilj našeg istraživanja bio je utvrditi jednadžbu za procjenu dentalne dobi u adolescenata, odraslih i starijih osoba na temelju debljine nataloženog dentalnog cementa.
Materijali i metode: Uzorak istraživanja činilo je 206 doniranih jednokorijenskih, i višekorijenskih zubi osoba oba spola (124 ženska i 82 muška, dob 10 do 82 godine). Korijeni su poprečno rezani (6 rezova) na rezaču ISOMET 1000 na apikalnim, srednjim i cervikalnim dijelovima (debljina rezova 0,3 do 0,5 μm). Mjerenja debljine cementa na rezovima obavljena su svjetlosnim mikroskopom i fotoaparatom Olympus EP50 uz prethodnu kalibraciju mikroskopa za svaku epizodu mjerenja. Mjerenja su provedena u smjeru kazaljke na satu na 4 mjerne točke na svakom rezu. Statističke analize provedene su korištenjem statističkih programskih paketa STATISTICA verzija 12.0 (StatSoft, Inc. (2013) i MedCalc® verzija 22.0.
Rezultati: Utvrđen je statistički značajni pad srednje debljine cementa (SDC) od apikalnih do cervikalnih rezova (F=480,8, p<0,001, post-hoc usporedbe p<0,05 za svaki rez, Friedmanova ANOVA). Utvrdili smo da nije bilo značajnih razlika SDC-a za spol (F=0,80, p=0,547) iako je SDC kod muškaraca bio deblji za sve rezove. Utvrđen je značajno veći SDC za skupinu zuba s više naspram skupine s jednim korijenom (F=2,25, p=0,047). Također je utvrđena i značajna razlika SDC-a među tipovima zuba (sjekutići, očnjaci, pretkutnjaci i kutnjaci) (F=2,41, p=0,002), s time da kutnjaci imaju značajno veći SDC od sjekutića (p<0,001, post-hoc analiza). Utvrđena je značajno veća SDC kod zuba s destrukcijom krune u odnosu na intaktne (F=18,46, p<0,001). Utvrđeno je da postoji značajan porast SDC do 6. desetljeća te pad nakon toga (F=2,03, p<0,001). Korištenjem linearne regresijske analize prema dijelovima kronološke dobi (piecewise linear regression analysis), kao prijelomna točka utvrđena je dob od 53 godine pa su izračunate dvije različite jednadžbe (≤53 godine i >53 godine).
Zaključci: Potvrđena je H1 hipoteza da se dentalna dob može procijeniti mjerenjem debljine zubnoga cementa. Točnost procjene ovisi o tipu zuba te stupnju oštećenja zubne krune. Nije potvrđena hipoteza H2 da je debljina zubnoga cementa veća kod muških ispitanika. Utvrđeno je da je kalibracija mikroskopa izrazito važna za točnost mjerenja debljine cementa. Izveli smo formulu za procjenu dentalne dobi u odraslih i starijih osoba temeljem mjerenja debljine istaloženog zubnoga cementa i to zasebno za dvije dobne skupine (<53 i >53 godine). |
| Abstract (english) | Objective: The aim of this research was to establish an equation for estimating dental age in adolescents, adults and the elderly based on the thickness of deposited dental cement.
Materials and methods: The research sample consisted of 206 donated single-rooted, tworooted and three-rooted teeth of both sexes (124 female and 82 male aged 10 to 82). The roots were transversely cut (6 cuts) on an ISOMET 1000 cutter at the apical, middle and cervical parts (slice thickness 0.3 to 0.5 μm). Measurements of the thickness of the cementum on the
cuts were made using a light microscope and an Olympus EP50 camera with prior calibration of the microscope for each measurement episode. Measurements were made clockwise at 4 measurement points on each slice. Statistical analyzes were performed using the statistical software packages STATISTICA version 12.0 (StatSoft, Inc. (2013) and MedCalc® version 22.0.
Results: A statistically significant decrease in mean cementum thickness (MCT) was found from apical to cervical slices for each slice (F=480.8, p<0.001, post-hoc comparisons p<0.05 for each slice, Friedman's ANOVA). The results revealed that there were no significant differences in MCT for gender (F=0.80, p=0.547) although MCT was thicker in men for all cuts. A significant difference of MCT was found for the group of teeth with one versus the group with multiple roots (multiple roots have thicker MCT, F=2.25, p=0.047). A statistically significant difference was also found for MCT among tooth types (incisors, canines, premolars and molars) (F=2.41, p=0.002), with molars having a significantly greater MCT than incisors
(p<0.001, post-hoc analysis). A significantly greater MCT was found in teeth with crown destruction compared to intact teeth (F=18.46, p<0.001). When MCT was compared between age by decade, it was found that there was a significant increase in thickness up to the 6th decade and a decrease thereafter (F=2.03, p<0.001). Using piecewise linear regression analysis,
the age of 53 was determined as the breaking point, hence two different equations were calculated (≤53 years and >53 years). When molars were analyzed separately, a significant increase in MCT through all decades of chronological age were found regardless of cuts (p<0.001, ANOVA), and dental age prediction equation was determined separately for molars.
Conclusions: The H1 hypothesis that dental age can be estimated by measuring the thickness of dental cementum was confirmed. The accuracy of the assessment depends on the type of tooth and the degree of damage to the tooth crown. Hypothesis H2 that the thickness of dental cementum is greater in male subjects was not confirmed. It was found that the calibration of the microscope is extremely important for the accuracy of the cement thickness measurement, and that a standard template should be used for its calibration. We derived a formula for estimating dental age in adults and the elderly based on the measurement of the thickness of deposited dental cement, separately for two age groups (< and >53 years old) in case we use any type of teeth. Also, we derived an additional formula that we use to estimate dental age if we have as a sample where measurement of the cement thickness can be done in one of the molars. |
