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Svrha provedenog istraživanja bila je ispitati kako vibracijski podražaji, kao neinvazivne i relativno jednostavne fizikalne metode, djeluju na ortodontski postupak. Ortodontski model primjenjen je na štakorima kojima su prvi maksilarni kutnjaci bili pomicani prema sjekutićima, mizijalno, u trajanju od 2 tjedna. Vibracijski podražaji primijenjivani su 2 puta tjedno u trajanju od 10 minuta okomito na okluzijsku površinu kutnjaka. Koristili smo dvije vibracijske frekvencije, 30 i 60Hz, jednake sile djelovanja od 0,4N. Obje korištene frekvencije pokazale su usporenje ortodontskog pomaka. To usporenje najvjerojatnije je bilo izazvano djelovanjem vibracijskiih podražaja na aktivnost osteoklasta i kočenje resorpcije alveolarne kosti. Resorpcija je vrlo važna i neizbježna pojava tijekom ortodontskog pomaka. Kao nuspojava zabilježena su značajna ostećenja stanica i dezorganizacija kolagenskih vlakana unutar parodontnog ligamenta najvjerojatnije izazvana prevelikom silom vibracijskih frekvencija (0,4N). Sve navedene promjene bile su jače izražene kod frekvencije od 30Hz nego od 60Hz. U budućnosti su potrebne dodatne studije koje bi detaljnije istražile utjecaj čitavog raspona vibracijskih sila i frekvecija na alveolarnu kost i koštanu pregradnju koja se javlja tijekom ortodontskog postupka. Rezultati ove studije upućuju na zaključak da vibracijski stimulusi, zbog potencijalnog kočenja aktivnosti osteoklasta i resorpcije kosti, mogu imati korisnu primjenu pri prevenciji ortodontskog relapsa koji se javlja neposredno nakon završetka ortodontskog tretmana i predstavlja veliki klinički problem u ortodonciji., In this study we wanted to investigate how cyclical (vibratory forces), as noninvasive and relatively simple and nonexpensive psysical methods, could affect orthodontic tooth movement in rats. Two different vibrational frequences, 30 and 60Hz, at the force of 0.4Newton were applied oclusally twice a week for 10 minutes in experimantal rats where the first left maxillary molars were moved mesially for 2 weeks. Both vibrational frequencies inhibited the amount of tooth movement. That effect was probably caused by the inhibition of osteoclastic activity and alveolar bone resorption that is important and necessary event during the orthodontic tooth movement. We also found that vibratory forces caused increased number of apoptotic cells and marked disorganization of the collagen fibril structure within the periodontal ligament, probably due to the excessive force levels used in these experiments. All changes were more prominent with 30Hz vibrational frequencies. Future studies should include additional analysis that would evaluate the effect of the whole range of vibrational forces and frequencies on the alveolar bone and resorption during the ortodontic tooth movement. Those studies should also evaluate more carefully the frequency and the point of their application (vibrating the alveolar bone directly insead of the tooth crown). Based on the results from this study, vibratory forces, because of their inhibitory effect on osteoclastic activity and bone resorption and decceleration of tooth movement, could have a significant impact and clinical use in the prevention of the orthodontic relapse, unwanted orthodontic event that occurs immediately after the termination of treatment and present an enormous problem in orthodontics.

Cilj istraživanja: Svrha istraživanja bila je utvrditi razliku između parametara kranijalne baze, maksile, mandibule i dentoalveolarnih parametara između klase I, klase II potklase 1, klase II potklase 2 i klase III. Materijali i metode: U ispitivanju su korištene 43 laterolateralna rendgenograma glave ispitanika snimljena prije ortodontske terapije. Kefalometrijska obrada provedena je u računalnom programu AudaxCeph (Audax, Ljubljana, Slovenija) korištenjem Zagreb 82 i Ricketts analize. Za svakog ispitanika su mjerene 24 linearne i kutne varijable. Rezultati: Nema statistički značajne razlike među mjerenim parametrima kranijalne baze unutar pojedinih skeletnih klasa. Duljina korpusa maksile (SNA-SNP) ne pokazuje statistički značajnu razliku između ispitivanih skeletnih klasa (51,22±3,27 mm vs 52,29±3,70 mm vs 53,04±2,00 mm; P=0,068), dok duljina korpusa mandibule (Me-Go) pokazuje statistički značajnu razliku između skeletne klase II i skeletne klase III (64,19±4,90 mm vs 70,81±5,08 mm; P=0,039). Vrijednost interincizalnog kuta u ispitanika sa skeletnom klasom II/1 su manje, a u ispitanika sa skeletnom klasom II/2 i skeletnom klasom III veće u usporedbi s ispitanicima sa skeletnom klasom I (119,01±7,07° vs 145,77±7,37° vs 138,54±5,73 ° vs 129,02±11,82°; P, Objectives: The aim of the study was to determine the difference between cranial bases, maxilla, mandible, and dentoalveolar parameters between class I, class II/1, class II/2, and class III. Materials and Methods: In this study there were forty-three laterolateral head roentgenogram of participants captured before starting orthodontic therapy used. Cephalometric processing was performed in the AudaxCeph (Audax, Ljubljana, Slovenija) using Zagreb 82 and Ricketts analysis. Twenty-four linear and angular variables were measured for each subject. Results: There were no statistically significant difference between the measured cranial base parameters within the individual skeletal classes. The length of maxilla corpus (SNA-SNP) showed no statistically significant difference between the skeletal classes (51.22±3.27 mm vs 52.29±3.51 mm vs 56.11±3.70 mm vs 53.04±2.00 mm; P=0,068), while the length of mandible corpus (Me-Go) showed a statistically significant difference between skeletal class II and skeletal class III (64.19±4.90 mm vs 70.81±5.08 mm; P=0.039). The value of the interincisal angle was lower in participants with skeletal class II/1 and higher in participants with skeletal class II/2 and skeletal class III compared to participants with skeletal class I (119.01±7.07° vs 145.77±7.37° vs 138.54±5.73° vs 129.02±11.82°; P