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A-I) Pretreatment extraoral photographs.
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Radiographic evaluation of skeletal maturation with the hand-wrist film showed the ulna and the radial epiphyses were fused (skeletal maturation indicator = SMI 11), and her skeletal age was 16 years old (Fig 1S). 
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A-I) Pretreatment extraoral photographs.
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Radiographic evaluation of skeletal maturation with the hand-wrist film showed the ulna and the radial epiphyses were fused (skeletal maturation indicator = SMI 11), and her skeletal age was 16 years old (Fig 1S). 
A-D) TAD-RPE with acrylic coverage and facemask hooks on the maxillary first molars: Frontal, lateral and occlusal views before expansion. E-H) After 21 days of expansion.
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A TAD-Haas RPE, consisting of acrylic palatal coverage and bands attached to the maxillary first molars, was applied in order to minimize the buccal tipping of the alveolar bone and the molar axes (Figs 2A-D). Elastics were connected to the outer bow of the facemask in a 30? downward and forward direction, delivering 500 g of force per side for 13 to 14 hours per day, for 6 months (Figs 2E-H). Cone Beam Computed Tomography (CBCT)images at post-expansion confirmed a 5.7-mm skeletal expansion at the level of the first molars, which was maintained after the orthodontic treatment (Figs 7A-C, Table 2). 
Intraoral photographs (A-F), lateral cephalometric radiograph (G), and tracing (H) at completion of TAD-Haas RPE and facemask treatment.
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After the expansion was completed, the mandibular arch was bonded with self-ligating brackets (0.022-in preadjusted appliances, Roth prescription) (Figs 3A-F). A lateral cephalometric radiograph was taken after TAD-Haas RPE and facemask treatment (Fig 3G). Cephalometric tracing of post-TAD-Haas RPE and facemask treatment (Fig 3H) showed the maxilla protracted forward and downward, and there was clockwise rotation of the mandible.
A-F) Molar bands were removed and mandibular leveling and alignment was completed. G-L) Completion of maxillary molar distalization.
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TADs, to increase anchorage and control the vertical dimension (Figs 4A-F). The maxillary distalization for Class II correction was initiated bilaterally, with open coils between second premolar and first molar. Then, sequential distalization was accomplished (Figs 4G-L).
A-I) Post-treatment extraoral photographs.
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The facial profile was enhanced, with maxillary lip support and nasolabial angle reduction, utilizing maxillary protraction (Figs 5A-I). Ideal anterior coupling, midline correction, and Class I canine and molar relationships were achieved (Figs 5J-O). The post-treatment panoramic radiograph showed excellent root parallelism and minimum root resorption (Fig 5P). The post-treatment lateral cephalometric radiograph, tracing and the superimpositions exhibited maxillary downward and forward movement (Figs 5Q-R, Figs 6A-C).
Pretreatment (black), post-TAD-Haas RPE and facemask treatment (blue) and post-treatment (red) cephalometric tracings superimpositions: A) superimposed on the sella-nasion plane at sella; B) superimposed on the palatal plane at ANS; C) superimposed on the mandibular plane at menton.
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The post-treatment lateral cephalometric radiograph, tracing and the superimpositions exhibited maxillary downward and forward movement (Figs 5Q-R, Figs 6A-C).
Measurements at pretreatment (A), post-expansion (B), and post-treatment (C). a = suture (mm), b = U6 basal bones (mm), c = U6 furcations (mm), d = U6 CEJs (mm), and e = U6 palatal cusps (mm).
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Cone Beam Computed Tomography (CBCT)images at post-expansion confirmed a 5.7-mm skeletal expansion at the level of the first molars, which was maintained after the orthodontic treatment (Figs 7A-C, Table 2). 
Extraoral (A-D) and intraoral photographs (E-J) at 18-month retention.
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At the 18-month retention visit, excellent stability of the treatment results was shown (Figs 8A-D). Angle Class I molar relationship, anterior overjet and overbite were maintained (Figs 8E-J). Figures 8K and 8L depict the profile changes through the treatment. The lateral cephalometric radiograph and tracing of post-treatment and 18-month retention (Figs 8M and 8N) showed the maxilla was stable, mandible presented backward rotation, and maxillary incisors were tipped back slightly.