Mario Legović

Regression equations for determining mesiodistal crown diameters of canines and premolars.

In this study, regression equations (prediction equations) were established for the purpose of accurately predicting the widths of the crowns of unerupted canines (C) and premolars (P1 and P2) on the basis of the measured mesiodistal diameter (MDD) and vestibulooral diameter (VOD) of the crowns of the erupted central and lateral incisors (I1, I2) and first permanent molars (M1). On the plaster casts of 120 subjects (60 boys and 60 girls), MDD and VOD of the crowns of I1, I2, C, both P1 and P2, and M1 on both sides in both jaws were measured twice, with a time distance between measurements. Gradual regression equations were derived on the basis of the measurement results, by which the sums of the widths of crowns of C, P1, and P2 can be predicted using three to five predictors. The coefficients of multiple correlations regarding the sex and the jaw varied from 0.79 to 0.85.

The Reliability of Chronological Age Determination by Means of Mandibular Third Molar Development in Subjects in Croatia

Abstract:  The aim of this study was to determine the development of the mandibular third molar and its relation to chronological age. The evaluated material consisted of 979 orthopantomograms of patients of Croatian Caucasian origin aged between 5.7 and 14.6 years. Third molar developmental stages were evaluated according to the stages proposed by Nolla. The frequencies of different stages of mineralization and the mean value of the mineralization of the mandibular third molars with regard to age, gender, and size of the mandible were determined and the coefficient of correlation determined between the age of the subject and the stage of development of the mandibular molars. Statistically significant correlation was determined between mineralization of the mandibular third molar and chronological age of the subjects (boys, mandibular left third molar r = 0.779, right third molar r = 0.793; girls, mandibular left third molar r = 0.746, right third molar r = 0.725). It can be concluded that the accuracy of age estimation based on Nolla’s method is applicable for Croatian children.

Secular Trend in the Development of Permanent Teeth in a Population of Istria and the Littoral Region of Croatia

The study evaluated secular trends in dental development during a period of 30 years, correlation between dental and chronological age in Istria and the littoral region of Croatia. The sample consisted of 1000 panoramic radiographs of children, aged 6–16 years (mean 10.0 ± 1.8), taken in the period 1977–1979 (N = 500; 243 females) and 2007–2009 (N = 500; 299 females). Dental age was assessed according to Demirjians method. Correlation between chronological and dental age was linear, positive, high, and statistically significant in both periods and genders, ranging from 0.73 to 0.86. Dental age was underestimated when compared to chronological age by 1 year on average, more 30 years ago (−1.35 ± 1.17) than today (−0.63 ± 1.09), less for girls (−0.80 ± 1.22) than boys (−1.21 ± 1.10). A statistically significant positive secular trend in acceleration of dental development was present of 0.72 years during the 30‐year period and was more significant in girls than boys (0.83‐ and 0.51‐year acceleration).

Secular trend of earlier onset and decelerated development of third molars: Evidence from Croatia

The purpose of this study was to evaluate the influence of the secular trend on development of third molars in 30 years period in Littoral region of Croatia. A total of 1103 panoramic radiographs of subjects aged from 6 to 18 years were analysed. First group comprised 531 panoramic radiographs (258 girls) taken from year period 1977 till 1979 and second group 572 radiographs (325 girls) taken from year period 2007 till 2009. Demirjians method was used to determine the developmental stage of third molars. A secular trend in 30 years period was observed as earlier onset of third molars development in boys (6 months on average maxillary and 11 months mandibular) and girls (6 months for maxillary and 4 months for mandibular). Now-a-days, an increase in mineralisation for one Demirjian stage occurs at a slower pace of 5.2 months in boys and 3.4 in girls in maxilla and 2.3 or 2 months in mandible for boys and girls, respectively. The study showed a secular trend present as earlier onset but decelerated development of third molars in both genders and both jaws.

Biological predictors of mandibular asymmetries in children with mixed dentition

Objectives: The objective was to investigate the severity of skeletal mandibular asymmetry in children with mixed dentition and other factors associated with asymmetry. Method: The study was cross sectional, with stratified sampling according to malocclusion type consisting of 205 subjects with mixed dentition (median 10, interquartile range 9–11 years). There were 59 subjects presenting Class II/1, 77 Class II/2, and 69 Class III. The mandibular asymmetry has been estimated from orthopantomograms using the Habets’ method and the dental maturation by Demirjian’s method. The sagittal skeletal relationship and facial growth pattern were assessed from lateral cephalograms. Results: Asymmetries in general, were not rare and were more present in the condylar height rather than in the height of the ramus. The highest severity of condylar asymmetry was in Class II/2 subjects (median of asymmetry index 7.3; 64% subjects exhibiting moderate and severe asymmetry), while the Class III subjects exhibited the highest severity of both ramus and total height asymmetry (2.1; 13% and 2.0; 15%, respectively). Multiple logistic regression unveiled male gender as the only predictor of moderate or significant overall asymmetry. Dental age, the difference between dental and chronological age, and facial growth pattern were not significant predictors of asymmetries. Discussion: Overall, asymmetries in mixed dentition cannot be considered rare; however, no strong relationships between asymmetry and observed biological factors were found.