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ePaper created 2016-04-19, 11:44:05 | version 1.38.0
palatal expansion screw industry report | 33 ortho 1 2016 with a very visible arrow printed on the body of the Expander. The screw is activated by turning the key as far as it will go. At the end of each activation a loud click sound is heard, which is made when it meets the braking ring, provided with the device. The braking ring prevents the screw from unwinding when the activation screw is removed. This en- sures the screw has been activated correctly and allows for the simple reinsertion of the key at the next activation, leaving the insertion hole per- fectly accessible. There are notches for controlling how much the Expander is activated. Thefirsttwonotchesarestampedontothebody of the Expander, while the others are stamped on the concentric sliding guides. The latter notches are therefore visible during activation while the screw is opening. The notches are positioned 2 mm apart from each other. Each activation moves the screw forward by 0.2 mm, corresponding to a 1/4 turn of the total circumference of the screw. The screw is therefore particularly stable for the whole expansion process; this is thanks to the double concentric sliding guide, which is one of the peculiarities of this Expander. The Expander remains stable until its maximum opening limit is reached, at which point it blocks without disconnecting the screw itself, thanks to a solid stopping device. This means it is possible to take advantage of the full length of the screw in absolute safety. Clinical test (Figs. 3a–e) WetestedtheExpanderona5-year-oldpatientwith a left-sided cross bite. We wanted to choose a very young patient with a very small palate, given that it is mainly in these patients that difficulties are most fre- quentlyencounteredwhenactivatingthescrews.These difficulties are linked to the confined spaces available for operating in. As a result, when the parent removes thekeyafteractivatingthescrew,he/shealmostalways tendstobringthescrewbackagain,reducinghowmuch theyhaveactivateditby.Asaresult,itisdifficultforthe cliniciantoevaluatetherealamountofexpansion. Activation protocol The Expander was bonded to two bands and ce- mentedontotheseconddeciduousmolarsandtherapid expansion protocol was implemented, which provides fortheactivationofthescrewtwiceaday(Figs.4a&b). Weaskedtheparentstodothisthemselves,butre- mained contactable at all times for anything they needed or in case of emergency. Figs.3a–e: Five-year-old patient with left-sided cross bite. Figs.4a & b:The Expander was bonded to two bands and cemented onto the second deciduous molars. Figs.5a & b: On the 14th day we terminated activation as the pre-determined expansion level of 5.5 mm had been reached. Fig.3a Fig.3b Fig.3c Fig.3d Fig.3e Fig.4a Fig.5a Fig.4b Fig.5b 12016