Bioprogresivna tehnika jest fiksna ortodontska tehnika nastala 1950- -tih godina na temelju edgewise tehnike. Njezin je utemeljitelj Robert Murray Ricketts. Ovaj rad donosi kratak pregled povijesti fiksne ortodoncije, objašnjava nastanak i razvoj Rickettsove tehnike, načela na kojima se temelji i metode kojima se ta tehnika koristi. Naglašen je Rickettsov doprinos ortodontskoj dijagnostici, predviđanju rasta pri planiranju i provedbi ortodontske terapije, a Rickettsova je bioprogresivna “filozofija”, kako ju zove sam autor, dovedena u kontekst i vezu sa suvremenim ortodontskim tehnikama.The bioprogressive technique is a fixed orthodontic technique, developed in the 1950s by Robert Murray Ricketts. This article provides a brief overview of the history of orthodontic practice, explaining the development of “Ricketts technique”, methods and principles that are incorporated in his bioprogressive therapy. It also discusses the importance of diagnostic methods, introduced by the author, that are still recognized as an important part of orthodontic therapy planning. This article explains the influence of bioprogressive philosophy on modern orthodontic techniques

Martina Mikšić

Mladen Šlaj

Senka Meštrović

Mikšić, Martina

Šlaj, Mladen

Meštrović, Senka

Hrčak - Portal of scientific journals of Croatia

A S CActa Stomatol Croat, Vol. 37, br. 4, 2003. 461Bioprogressive Therapy andDiagnosticsSummaryThe bioprogressive technique is a fixed orthodontic technique, devel-oped in the 1950s by Robert Murray Ricketts. This article provides abrief overview of the history of orthodontic practice, explaining thedevelopment of “Ricketts technique”, methods and principles that areincorporated in his bioprogressive therapy. It also discusses the impor-tance of diagnostic methods, introduced by the author, that are still rec-ognized as an important part of orthodontic therapy planning. This arti-cle explains the influence of bioprogressive philosophy on modern ortho-dontic techniques.Key words: Bioprogressive therapy, Ricketts technique, VTO.Martina MikπiÊMladen ©lajSenka MeπtroviÊDepartment of OrthodonticsSchool of Dental MedicineUniversity of Zagreb Acta Stomat Croat2003; 461-464REVIEWReceived: October 21, 2003Address for correspondence: M. Sc. Martina MikπiÊ, D.M.D.Department of OrthodonticsSchool of Dental MedicineGunduliÊeva 5, 10000 ZagrebCroatiaPhone: +385 1 480 2 141e-mail:martina.miksic@zg.hinet.hrIntroductionThe bioprogressive technique, developed fromthe edgewise technique, also contains elements ofthe light wire technique. In 1925 Angle describedthe edgewise appliance (1). In the 1930’s many arti-cles about the application of this technique were pub-lished (2, 3). The originally described edgewise (theso-called “primary edgewise”) is a technique inwhich bands are cemented to teeth and the therapybegins when all the permanent teeth have erupted.Brackets on the bands have a straight slot and thewire engaged into the brackets needs to be bent inorder to secure the movements and a regular arrange-ment of the teeth in the dental arch. Rotations andhorizontal movements of the teeth (in/out) were doneby first-order bending (“step” and “bayonet”), whilethe torque was done by third-order bending. Teethangulation (second-order movement) was accom-plished by positioning the bracket to the band at anangle, i.e. with an inclination in the mesiodistal planeor, alternatively, the band was cemented at a certainangle. The dimensions of the soft gold alloy wireused by Angle are 0.022” x 0.028”. The main fea-ture of edgewise is that control of tooth movementsin all three dimensions is achieved throughout thetherapy.The second stage of the development of the edge-wise technique (“secondary edgewise”) is charac-terized by the use of a round wire in the straight slotof the edgewise bracket. The round wire, used inleveling, results in the undesirable flaring of theteeth, particularly expressed in the lower dental arch.The third stage of the development of edgewise(“tertiary edgewise”) may be looked upon as a mod-ification of the secondary edgewise, also calledTweed edgewise. Tweed introduces the use of ClassIII elastics, beside the “tip-back to-hold” anchor-age in the lower arch, in order to avoid labial tip-ping of the lower incisors brought by the use ofround wire. He is the first to use 0.0215” x 0.025”stainless steel wire.Since the clinicians were trying to improve andmodify the original method in their everyday work,A S C Acta Stomatol Croat, Vol. 37, br. 4, 2003.462Martina MikπiÊ et al. Bioprogressive Therapynew challenges relating to the edgewise techniqueappeared in the 1940’s. Objections were raised tofrequent resorptions of roots and the appearance ofbialveolar protrusion in the therapy of deep bite dueto the use of round wire in the leveling stage. Inad-equate therapy frequently resulted in the extractionof the first premolars (4).Advantages of the use of light forces in contrastto heavy forces and their effect on tooth movementwas frequently discussed in the 1950’s (5, 6).All these stages of the edgewise technique devel-opment have served as the basis for the developmentof the bioprogressive method. Ricketts proposes thebioprogressive technique as an answer to the needsof orthodontic therapy.Development of the bioprogressive techniqueBioprogressive therapy was so named because itprogressively includes particular groups of teeth intothe therapy (first the molars and the incisors, fol-lowed by the canines and the premolars), with ther-apeutic interventions applied in a planned sequence.There are three varieties of the technique thatmay be used. They are all based on the basic pre-sumptions of the bioprogressive concept. These arethe following: bioprogressive setup, full-torque bio-progressive arrangement and triple-control biopro-gressive (7). In the standard bioprogressive setup torque isincorporated in the brackets for the upper incisorsand all four canines. First and third-class bendingfor the lateral lower segment is still done on the wire. In the full-torque bioprogressive arrangementthe setup in the superior arch is like the standardsetup, but in the inferior arch a torque is added tothe tube of the lower molar and the bracket of thelower second pre-molar. At this stage there is noneed for third order bending, except in some cases,which greatly facilitates the orthodontist’s work.First order bending is still done on the wire.In the triple-control bioprogressive setup thebracket design also includes first order movements.Brackets of the upper canines and the second upperpremolar are thicker in order to ensure the buccalmovement of the first premolar and/or molar. Also,a distal offset for the rotation of the upper molar hasbeen added to the tube. This is the true straight-wiretechnique; there is no need for bending the wire atall, all movements are ensured by the design and/orby the correct setup of the appliance (8). Today’s Ricketts brackets of slot dimension0.018” also come in the so-called standard and thebioprogressive setups. The only difference is thatthe torque in the bracket for the lower second pre-molar in the bioprogressive variety is -14°, whilein the standard variety it is 0° (Table 1).The values of torque and angulation differ sig-nificantly in relation to the widely used Roth tech-nique (Table 2).Elements of the bioprogressive techniqueThe wire used in the bioprogressive techniqueis Elgiloy 0.016”x0.016”. The size of the wire isstandardized for individual cases. The distance fromthe distal edge of the lateral incisor of one side tothe distal edge of the other side is measured. Thesame wire size is used for an individual patient atdifferent stages of therapy, e.g. ideal arch size 5, fin-ishing arch size 5, etc. The following arch types areused: ideal arch, utility arch, double-delta arch,closed-helix arch and finishing arch.The ideal arch is used at the initial stage of ther-apy to form the individual dental arch. Pre-fabri-cated arches are used, that already have bent insetsand offsets. The form of the arch is characterized byits straightening in the canine region and the absenceof its prominence. The offset is distal from thecanines for the first premolar in both dental arches.Offsets are made for molars, too, as well as a distaloffset for the rotation of the lower molar (12°) andthe upper molar by 15°. In the triple-control bio-progressive setup no bending is needed, since it isall incorporated in the appliance.The double-delta arch (Figure 1) is used for clos-ing the space after segmental therapy and the closed-helix arch for closing the space. Its inverse use inthe superior arch, which at the same time torquesthe upper front teeth, is interesting. The finishingarch (Figure 2) has horizontal loops. 0.018” x 0.022”wire is used to close the space, torque the teeth andcontrol the form of the dental arch. A S CActa Stomatol Croat, Vol. 37, br. 4, 2003. 463Martina MikπiÊ et al. Bioprogressive TherapyBeside these standard wires, the bioprogressivetherapy applies other pre-fabricated segmental typeelements, such as maxillary cuspid retractor, man-dibular cuspid retractor (Figure 3), ideal buccal seg-mental arch, back action uprighter or intruder (Fig-ure 4), “T” arch and horizontal helix. The use of seg-mented arches has been introduced because of theneed to control movements of tooth groups or anindividual tooth more efficiently, particularly at thefirst stage of therapy (7, 9). The bonding of the archby a single, joint wire is postponed to a later stageof therapy by double-delta arches. Ricketts “utility” therapyThe utility arch (Figure 5) has been developedwithin a new approach to therapy. This is an archwhich starts the therapy, but it may also be used atany later stage of the therapy. The arch was named for the wide possibilities itoffers and for the various effects it can bring aboutduring the therapy. It has made possible a controlledlower incisor intrusion in cases of deep bite (10-15).The wire that is bent into the utility arch is a 0.016”x 0.016” blue Elgiloy. Unlike rigid stainless steel,this wire is made of chrome-cobalt alloy that maybe bent more easily. The warming of the wire is notrecommended for it increases the force the wireexerts; for a movement like intrusion a light forceshould be applied. Utility arch consists of a molarsegment inserted into the molar tube, with the pos-terior vertical segment joined to it at a 90° angle;this segment is usually 3-4 mm long in the mandibleand 4-5 mm long in the maxilla. Its extension is avestibular segment passing at the level of the mar-ginal gingiva edge without touching it. It is followedby the anterior vertical segment 4-5 mm long in themandible and 5-8 mm in the maxilla, joined by theincisal segment, which passively lies in the brack-ets of the incisors before it is activated. The utilityarch looks the same at the other side, ending in thetube of the opposite side molar. With regard to appli-cation, there are four different utility arches.The passive utility arch is used for preserving thespace or for stabilization in mixed and in permanentdentition. In mixed dentition it can preserve spaceduring the replacement of teeth, preventing mesialmolar movement. By moving the cheeks away fromthe lateral teeth, the arch facilitates the transversalexpansion. In permanent dentition it is primarilyused to preserve anchorage.The intrusion utility arch looks like the passivearch but is activated for the intrusion of the frontteeth, against which a continuous light force is exert-ed. Beside intrusion, the bending of the wire gingi-vally on its way out of the molar tube has a retru-sion effect and prevents labial tipping of the lowerincisors during the intrusion.The retrusion utility arch is used in mixed and inpermanent dentition for the intrusion and retrusionof the incisors. The arch contains loops and is acti-vated like the previously described intrusion arch.The protrusion utility arch protrudes and intrudesthe upper and the lower incisors. It is usually usedin Class II/2 therapy.Ricketts cephalometric analysisRicketts analysis has undergone a series of mod-ifications. The first version had only five variables.The analysis was later expanded by the introductionof new points and lines (Figure 6,7). Originally,Ricketts points were the following: Xi - the geo-metric centre of the ramus of mandible; PM - pointon the front border of symphysis between point Band Pog; DC - point in the centre of the condyle neckat the point it crosses the BaN line. Beside this, Rick-etts introduced changes that happen during growthinto his analysis (Table 3) and on the basis of thempredicts the ultimate result of the therapy (VTO -Visual Treatment Objective). Beside the cephalo-metric analysis and the prediction of growth as theguidelines for the therapy, the author also mentionsthe “intuitive” planning of the therapy as being ofthe same importance (16, 17). Analysis of profile soft tissuesAn important factor in the analysis of profile softtissues is the aesthetic line (Ricketts E-line) whichconnects the pogonion point with the tip of nose, i.e.the pronasal point (Figure 8). In mixed dentition, both lips are on that line (18,19). With age the lips retract, moving behind the aes-thetic line in a young adult: the lower lip by 2 mmand the upper by 3 mm (12).A S C Acta Stomatol Croat, Vol. 37, br. 4, 2003.464Martina MikπiÊ et al. Bioprogressive TherapyThis analysis makes a distinction between threefacial types: Concave - the lips lie behind E-line above average; Flat - average position of the lips (lower 2 mm, upper3 mm behind E-line);Convex - the lips are touching or are in front of E-line.The height of the upper lip and the contact linebetween the lips and the occlusal plane are analyzedon the profile, too. The distance between the sub-nasal point and the point of lip contact is measured.The occlusal plane is normally 3.5 mm below thelip contact line (at the age of 8-9 years). Each yearthis distance shortens by 0.1 mm until growth com-pletes. An estimate of the height of the upper lip isimportant for determining the optimum position ofthe incisors. If the occlusal plane is high, the teethremain hidden behind the lips and it is recom-mended, for aesthetic reasons, that the position ofthe occlusal plane is changed to bring it as close aspossible to the normal relationship with the lip (18). ConclusionAlthough presented more than half a century ago,Ricketts technique is still modern. It is based on thebiologic principle of the use of very light forces.Principles, developed and designed more than halfa century ago, are present in today’s techniques(Alexander, MBT, Roth...) which use continuouslight forces for the movement of teeth, using newtechnologies (nickel-titanium martensitic archwires). The use of the utility arch introduced by Rick-etts makes possible fixed therapy in the early mixeddentition (20, 21). Segment arches facilitate themovement of individual teeth in the desired direc-tion and the anchorage may be planned more effi-ciently.Another advantage of the bioprogressive tech-nique, emphasized by the author himself, is that itspurpose is not an absolute standardization of treat-ment; there are certain principles, but the diagno-sis, planning and manner of the therapy are indi-vidualized to fit the specific needs of each patient(8). There is no doubt that the introduction of Rick-etts cephalometric analysis and VTOs into ortho-dontic diagnostics is very significant. Today thereis almost no diagnostic software that does notinclude the parametres of Ricketts analysis as its keyelement. Ricketts E-line is not only an important partof the analysis of soft tissues, but also a matter ofaesthetics, which is an indispensable part of con-temporary orthodontics.

Bioprogressive Therapy and Diagnostics

Abstract

Similar works

Full text

Available Versions

Hrčak - Portal of scientific journals of Croatia