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Fig. 2. Pretreatment facial photographsFig. 3 Pretreatment cephalometricsmandibular incisor in itspretreatment position. Thetotal difficulty index of 90confirms a difficult problemfor a deep bite Class II. Wedecided to manage thispatients’ treatment at 11years of age and use TweedMerrified mechanics as thesecond phase of a two phasetreament without premolarextraction.Fig. 4. Pretreatment dental castsFig. 5a. Orthopedic appliancePHASE 1First, we planned to treat the horizontal skeletalproblem in the late mixed dentition. An orthopedic appliance(Fig.5a) was worn at night for 6 months. This monoblochad a functional action on the tongue position and preventedthe thumb interposition. Its special design locked the lowerincisor in order to maintain its angulation on the mandibularplane. The acrylic bite plane was reduced in height in theposterior areas to allow lower molar eruption. Of note isthe improvement in the posterior occlusion (Fig. 5b). Thereis a class 1 relationship in the cuspid and bicuspid aeras.The overjet and the overbite have decreased. The facialphotographs (Fig. 6) show improvement of the face dueto a forward translation of the mandible. The Zangle (70°)increased, theAOBO (1mm)decreased due toan increase of theSNB angle (80°).The ANB angleFig. 5b. Post orthopedics (phase I)is now 2°. In thevertical, we notethe closure ofthe FMA from 23 to 22 degrees. IMPA remined at 98 degrees. The occlusal plane is stable (Fig. 7a). The generalsuperimposition (Fig. 7b) shows the growth “acceleration” of the lower jaw while maintaining the maxilla. Therewas no change in the lower and upper incisor position. The upper molar has been maintained in its vertical andhorizontal dimension. The lower molar has moved up and forward, carried by the forward movement of the lowerjaw and the necessity to fill in the free space.This first step allowed us to correct the class II skeletalproblem with a minimum of cooperation. This protocol might movesome extreme low angle malocclusions out of a surgical plan.Fig. 6. Postorthopedic facial photographs (II)PHASE 2A set of records taken in the early permanent dentitionenabled us to evaluate the residual occlusal deficit (Fig. 8). Thepatient is now easy to diagnose: a class 1 maloclusion with amoderate overjet and overbite, a mild curve of Spee, and some spaceson the upper arch. Our objective is to correct the incisor position43