The Step-by-Step Roncone PhysioDynamicSystem (PDS) Prescription

The Roncone PhysioDynamicSystem of interactive SLB’s, wire forces, wire sizes, archform, and bracket prescription will be shown to be very physiological and move teeth very quickly with “directional” forces. Additionally, there are little to no side effects which have to be compensated for during treatment. It will also virtually eliminate root resorption.

Let’s begin with the goals of the Roncone PhysioDynamicSystem.

They are:

To eliminate posterior balancing interferences
To eliminate anterior “overcoupling”
To control anchorage without adding to the bracket system
To allow full tooth alignment and “arch fulfillment” with a light, round, titanium wire
To eliminate excessive curves of Spee and Wilson
To allow full functional finishing to be accomplished in a gentle manner in less than a full-sized wire

Upper Incisors

Increased torque so that finishing in less than a full sized wire will still give the torque necessary to eliminate “overcoupling” of the upper and lower anteriors, thus eliminating fremitus and post treatment relapse, or condylar displacement when fixed lower retainers are used.

U1 Torque 19° U2 Torque 10°

Tip 5° Tip 8°

Rotation 0° Rotation 0°

Upper Canines

Zero torque eliminates the heavy contact between the upper and lower canines, eliminating the lingual displacement of the lower canine and eventual lower anterior crowding. The angulation is appropriate to achieve proper canine guidance in both extraction and non-extraction cases.

Torque 0°

Tip 8°

Rotation 0°

Upper Premolars

The increased buccal root torque eliminates the lingual cusp interferences of other techniques and assists in “seating” the posterior occlusion. The distal root angulation counteracts any Class II elastic forces, seats buccal cusps, and achieves the most esthetic tooth position. The best tooth esthetics occur with an increased distal tip from incisors through premolars.

Torque -10°

Tip 4°

Rotation 2D°

Upper First Molars

Anchorage Molar (Used approximately 40% of the time)

In combination with large diameter round wires (.018 PDS thermal or (2) .014 PDS Superelastic) typical flaring of incisors is non-existent when bringing down high or impacted canines due to the rotation of the molar which causes significant friction/binding.

The increased buccal root torque eliminates lingual cusp balancing interferences. It provides incredible anchorage and virtually eliminates the need for TPA’s or Nance’s. Minimum anchorage cases can use the 20°/12° molar.

Torque -20°

Tip 0°

Rotation 20D°

Double buccal tubes on first molars are very useful to align upper 2^nd molars when the 20/20 molar is used.

Non-Anchorage Molar (Used approximately 60% of the time)

Used when anchorage is not a factor in treatment planning.

Torque -20°

Tip 0°

Rotation 12D°

Upper Second Molars

The upper second molar, as with all upper posterior teeth, have increased buccal root torque to eliminate balancing interferences. The shorter height of the lingual cusp allows for somewhat less torque than the first molar.

Torque -17°

Tip 0°

Rotation 12D°

When the 20/20 molar is used it is best to place the upper second molar tubes gingival to the height of contour and use a sectional 19×25 HANT from the auxiliary tube of the upper first molar to the second molar tube.

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Lower Incisors (Universal)

The positive torque of 2° is appropriate for finishing in less than a full-sized wire and for mechanics that are not totally dependent on heavy Class II mechanics such as Herbst, and heavy long term Class II elastics, etc.

Torque 2°

Tip 0°

Rotation 0°

Lower Canines

The decreased torque allows for a more upright and esthetic lower canine which harmonizes with the lower incisors and the upright lower first premolars. It also achieves, in combination with the zero torque upper canine, excellent guidance without too heavy of a contact. There is no mesial lingual rotation built into the slot which avoids the lingual rotation of the canine. The bracket can be placed in the middle of the crown where it belongs instead of guessing how far mesial it needs to be placed.

Torque -3°

Tip 5°

Rotation 0°

When a rectangular wire is placed the mesial of the lower canine will not rotate lingually! There is no anti-rotation built into the bracket. The bracket can be placed in the center of the tooth mesio/distally.

Lower First Premolars

Decreased lingual crown torque keeps excellent archform, avoids balancing interferences and a forward slide from C.R. to C.O. This slide is very common and is due to the excessive lingual tip of the first premolar in most techniques and a narrow archform in this area.

Torque -7°

Tip 2°

Rotation 2D°

Lower Second Premolars

This tooth is also very upright in keeping with the full arch philosophy.

Torque -10°

Tip 2°

Rotation 2D°

Lower First Molars

The large decrease in lingual crown torque eliminates the very common lingual “roll-in” of these teeth. Balancing interferences are eliminated also. The slight disto-lingual rotation fits beautifully with either the maxillary anchorage (20° T, 20° R) or non-anchorage (20° T, 12° R) molars.

Torque -13°

Tip 0°

Rotation 4D°

Lower Second Molars

Again, the lingual crown torque is significantly reduced from the majority of preadjusted prescriptions. The lower arch finishes with an upright, natural wide result which coordinates beautifully with the upper arch.