Fluctuating Dental Arch Asymmetry in Different Malocclusion Groups

Svrha: Željelo se usporediti stupanj fluktuirajuće asimetrije (FA) zubnih lukova između pacijenata s anomalijama klase I, II i III. Ispitanici i metode: Uzorak je obuhvaćao slučajno odabrane gipsane modele 131 pacijenta – 39 s klasom I (19 muških i 20 ženskih), 57 s klasom II (23 muška i 34 ženska) i 35 s klasom III (20 muških i 15 ženskih). Dentalni modeli skenirani su i digitalizirani skenerom ATOS II SO. Mjerenja zuba i zubnih lukova obavljena su softverom ATOS viewer verzije 6.A.2. Mjereno je šest širina i pet dužina zubnih lukova. FA je procijenjena u obliku složenog indeksa ukupne težinske asimetrije (TWA). Za komparaciju razlika među skupinama korištena je analiza varijance. Rezultati: Složene TWA mjere fluktuirajuće asimetrije za varijable zubnih lukova bile su najviše u klasi III i najniže u klasi I. Ispitanici su pokazivali viši stupanj asimetrije od ispitanica. Asimetrija zubnih lukova bila je viša u mandibuli negoli u maksili u svim skupinama malokluzija. Zaključci: TWA vrijednosti bile su niske, ali su se značajno razlikovale među skupinama malokluzija. Anomalija klase III pokazivala je više vrijednosti FA-e od onih u klasi I i klasi II. Viša FA-e zubnih lukova u Angleovoj klasi III može se smatrati indikatorom povećane razvojne nestabilnosti u slučaju te malokluzije zbog visokoga genetskog i okolišnog stresa tijekom ranog razvoja.Objective: To compare the degree of dental arch fluctuating asymmetry (FA) among patients with Class I, II, and III malocclusions. Subjects and methods: The sample comprised randomly selected plaster casts of 131 patients: 39 Class I (19 males and 20 females), 57 Class II (23 males and 34 females), and 35 Class III (20 males and 15 females). Dental models were scanned and digitized using ATOS II SO. The measurements of the teeth and dental arches were taken using the ATOS viewer version 6.A.2 software. Six arch widths and five arch depths were measured. The FA was assessed as a composite index of total weighted asymmetry (TWA). The analysis of variance was used to determine whether there were any statistically significant differences between the groups. Results: Composite TWA measures of fluctuating asymmetry for dental arch variables were the highest in Class III, and lowest in Class I malocclusion. Males displayed a higher degree of asymmetry than females. The asymmetry degree was higher in the mandibular dental arches than in the maxillary dental arches in all malocclusion groups. Conclusion: The TWA values were low but they differed significantly between the groups of malocclusion. Class III malocclusion displayed higher FA values than Class I and Class II malocclusion. Higher FA of dental arches in Angle’s Class III can be considered an indicator of increased developmental instability in this malocclusion due to high levels of genetic and environmental stress during the period of early development