Effect of four premolar extractions on the vertical dimension of the face : A retrospective cephalometric study

PURPOSE Adequate control of the vertical dimension is of great importance in orthodontic treatment. Although existing evidence is very limited, extraction of four premolars is thought to contribute towards improved control of anterior facial height compared with non-extraction treatment protocols. Thus, the aim of this retrospective cohort study was to compare the effect of fixed-appliance treatment with extraction of four premolars to non-extraction treatment on the skeletal vertical dimension. METHODS A consecutive sample of 76 children with skeletal hyperdivergence (49% male; mean age 11.9 years) was divided into two groups for treatment with either non-extraction (n = 31) or extraction of four premolars (n = 45). Baseline characteristics were comparable: overjet 5.1 ± 2.5 mm, overbite 2.4 ± 1.9 mm, ANB angle 4.6 ± 2.3°, and SN-ML angle 40.2 ± 3.5°. Patients were treated with standard edgewise fixed appliances with closing loops/sliding mechanics. Vertical skeletal and dental outcomes were measured on lateral cephalograms before and after treatment. Data were analyzed with linear regression at 5%. RESULTS Compared to non-extraction treatment, treatment with premolar extractions had no significant effect on the SN-ML angle (difference (Δ) = 0.07°; 95% confidence interval -0.90 to 1.01°; P = 0.88). Statistically significant changes between the extraction and non-extraction groups were only found for the parameters SNA (Δ -1.47°; P = 0.003), ANB (Δ -1.17°; P = 0.004), SN-OP (Δ -1.48°; P = 0.04), and L1-ML (Δ -6.39°; P < 0.001). CONCLUSION Orthodontic treatment of children with skeletal hyperdivergence using systematic extraction of four premolars had minimal effects on the vertical facial dimension compared to non-extraction treatment

Looking at Zagreb: The Italian State as a Popularizer of Contemporary Art

In 1965, at the 12th International Conference of Critics, Artists and Art Scholars, held in Rimini, Verucchio and San Marino and devoted to the theme Art and Technology, Italian art critic Giulio Carlo Argan declared that Yugoslavia had overcome the problem of the relationship between art and technology. His statement concerned to the cultural milieu of Zagreb that Argan had known from the early Sixties. In the same year, Palma Bucarelli, the chief curator of the Rome National Gallery, attended the Brezovica conference held for Nova tendencija 3, to present a project in which the museum had a significant role as a state institution that had to encourage contemporary art in order to free artists from the pressures of the art market and private art galleries. In 1963, another art scholar, Umbro Apollonio, the curator of the Venice Biennale Archive for Contemporary Arts who had directly participated in the Venice exhibition Nuova tendenza 2, claimed that Italian Public Art School needed a new relationship between teaching and industries. My presentation aims to highlight how Argan, Bucarelli, Apollonio and other Italian scholars hoped for the state to intervene in the Italian art system and also how their ideas were inspired by the Croatian political and cultural situation of the 1960s