The T-Rex Appliance offers a two-phase approach: arch expansion followed by molar distalization. It employs a pre-activated .032 TMA wire, an expansion screw, and premolar rests. During expansion, a wire embedded in acrylic halts spring activation. Once arch development concludes, clinicians cut this wire, activating springs for molar distalization. An adjustment loop can assist molar rotation, and lingual sheaths, provided by the lab, are spot-welded onto the band.


  • Rests on d’s & e’s or 4’s & 5’s
  • Molar Distalizing Springs
  • Acrylic Palate
  • Lingual horizontal sheaths
  • Midline Expansion Screw
  • Soldered Wires from acrylic to molar bands
  • Bands on first molars

Suggested Materials:

  • .032 TMA wire for molar springs
  • .032 to .036 Chromium Cobalt or Stainless-Steel for the rests and soldered / laser welded Hold Wire on molar bands