Dentometrijske karakteristike ispitanika s primarnom kompresijom

Abstract

A comparative study of dentometric characteristics of incisors in the upper and lower jaws was performed in on attempt to determine the role of the size of the mentioned teeth in the process of primary crowding. The study included 200 examinees (140 females and 60 males) with primary crowding and 100 eugnathic subjects (48 females and 52 males) as a control group. The sample was selected according to the following criteria: anterior crowding, completed exchange of teeth, neutral intermaxillary relationship (Angle class I), lack of other malocclusion. The age was limited to 14 years in order to avoid the possible influence of tertiary crowding. The study was carried out by means of a sliding-caliper with 1 mm precision on plaster casts of the upper and lower jaws, and the mesiodistal diameters of all the four permanent incisors in the upper and lower jaws were measured. After statistical analysis and interpretation of the results, the following was concluded: Arithmetical means of the sums of the upper incisors were considerably higher in boys, while the difference between the mean values of the sums of the lower incisors was insignificant. The subjects with crowding had significantly bigger upper but not lower incisors. One of the important factors for the occurrence of crowding were bigger incisors, especially the upper central ones, and in girls also the lower incisors. The size of the incisors should by no means be taken as the only cause o f crowding, as demonstrated by the analysis of the widths and heights o f the upper dental arch. Significantly smaller widths of dental arches in the premolar and molar regions, along with an increase in the anterior upper height were registered in the subjects with crowding. The analysis of correlations revealed only a slight association between the size o f incisors, especially the upper ones, and the widths and anterior heights of the upper dental arch, possibly indicating a very low correlation or the lack o f correlation among the factors inducing crowding, i.e. increase in the size of incisors, and a narrower and longer upper dental arch.Provedeno je usporedno istraživanje dentometrijskih odlika sjekutiča u gornjoj i donjoj čeljusti s ciljem utvrđivanja uloge veličine navedenih zubi u procesu nastajanja primarne kompresije. Istraživanje je obuhvatilo 200 ispitanika (140 ženskih i 60 muških) s primarnom kompresijom i 100 eugnatih ispitanika (48 ženskih i 52 muška) koji su poslužili kao kontrolna skupina. Odabir je učinjen prema slijedećim mjerilima: zbijeni postav sjekutiča, završena mijena zubi, neutralni međučeljusni odnos (Kl I), odsutnost neke druge ortodontske anomalije. Dob je ograničena na 14 godina, kako bi se izbjegao mogući utjecaj tercijarne kompresije. Istraživanje je provedeno pomičnom kliznom mjerkom s točnošću od 0,5 mm na sadrenim odljevima gornjih i donjih čeljusti, a izmjereni su meziodistalni promjeri svih gornjih i donjih trajnih sjekutića. Nakon provedene statističke obrade i analize rezultata, može se zaključiti slijedeće: Aritmetičke sredine suma gornjih inciziva značajno su veće u dječaka, dok razlika između spolova za prosječne vrijednosti suma donjih inciziva nije značajna. Jedan od važnih čimbenika za nastajanje »crowdinga« je povećana zubna masa sjekutića, prvenstveno gornjih srednjih, a u djevojčica i donjih inciziva. Veličina inciziva nikako se ne može uzeti kao jedini razlog za nastanak kompresije, što potvrđuje i analiza širina i dužina gornjega zubnoga niza. U ispitanika s »crowdingom« zabilježene su značajno manje širine zubnih nizova u regiji premolara i molara te povećanje prednje gornje dužine. Analiza korelacija ukazuje tek na laganu povezanost ili nepovezanost veličine inciziva sa širinama i prednjom dužinom gornjega zubnog niza. To bi moglo ukazivati na vrlo malu povezanost, odnosno nepovezanost čimbenika koji dovode do »crowdinga«, a to su veći incizivi te uži i duži gornji zubni niz