Maxillary protraction and vertical control utilizing skeletal anchorage for midfacial-maxillary deficiency

ABSTRACT Introduction: The efficacy and efficiency of early treatment of skeletal Class III patients with facemask therapy are well-documented; however, very few cases for adolescents or adults were reported. Objective: The aim of this case report was to demonstrate skeletal and dental correction of a post-pubertal-growth-spurt patient whose malocclusion consisted of a skeletal Class III with slight transverse deficiency, a high mandibular plane angle, and a retrusive maxillary complex. Case report: A 13-year-5-months old Hispanic female was diagnosed as a retrognathic maxilla and mandible, a high mandibular plane angle, open bite pattern, a bilateral Angle Class I molar relationship with an anterior crossbite on the maxillary lateral incisors. A TAD-supported Haas rapid palatal expander was utilized for maxillary protraction combined with a facemask, vertical control, and maxillary molar distalization with fixed appliance. Results: The total treatment time was 26 months. An improved facial profile with maxillary lip support and more prominent cheeks was established. Adequate vertical control prevented a change in the mandibular plane angle even though facemask treatment can increase the vertical dimension. After the 18-month retention, excellent stability of the treatment results was shown. Conclusion: With skeletal anchorage and facemask treatment, orthodontists have the ability of expanding and protracting the maxilla without tipping maxillary molars buccally and without the risk of unfavorable periodontal consequences. A TAD-supported Haas rapid palatal expander allowed to control the vertical dimension and distalize molars, while minimizing undesired consequences.


INTRODUCTION
The efficacy and efficiency of skeletal Class III patients in early treatment are well-documented. Maxillary deficiency is often treated with maxillary protraction, and may be with or without palatal expansion. Treatment should be carried out in patients less than 10 years of age to enhance the orthopedic effect. 1,2 However, there are some reports in the literature that there is no statistically significant difference between younger and older (> 10-year-old) children. [3][4][5][6] Discrepancy between the skeletal and chronological ages may be a factor, and it might be better to consider the skeletal age as a clinical indicator to determine the effectiveness of using a facemask. 7 However, even if correction can be achieved in all growing patients, the skeletal changes may be smaller in older children. This case report demonstrates the efficacy of a TAD-supported Haas rapid palatal expander in conjunction with a facemask utilized for transverse correction, sagittal correction, and vertical control.

DIAGNOSIS AND ETIOLOGY
A 13-year-5-months old Hispanic female presented with the following chief complaint: "I don't like my front teeth, which are not straight". Her medical history was noncontributory, and she was in post menarche. She had routine hygiene visits every six months and was stable from periodontal and restorative perspectives. Her oral hygiene was fair.  The growth potential was evaluated, and cervical vertebrae maturation stage 8 demonstrated CS4, which indicated that her peak mandibular growth occurred within 1-2 years before this stage. Radiographic evaluation of skeletal maturation with the hand-wrist film 9 showed the ulna and the radial epiphyses were fused (skeletal maturation indicator = SMI 11), and her skeletal age was 16 years old ( Fig 1S).  Hence, the possible explanation would be early loss of maxillary deciduous dentition.   The post-treatment panoramic radiograph showed excellent root parallelism and minimum root resorption (Fig 5P).  (Table 1)

. 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).

Post-expansion (B)
Post-treatment (C)  and 8N) showed the maxilla was stable, mandible presented backward rotation, and maxillary incisors were tipped back slightly. Mandibular dentition was retained.  for skeletal Class III patients has been discussed regarding the timing, treatment duration, impact of the combination with RPE, and usage of skeletal anchorage devices. Facemask treatment is effective when patients starting the treatment are younger or older children. 6,12 However, after 10 years of age, decrease of the skeletal changes, increase of dental compensation, and longer treatment time were reported. [1][2][3][4][5]11,12 Even though skeletal Class III correction might be achieved in all age groups (3-12 years old), treatment should be started as soon as the diagnosis is made, because younger patients showed greater and faster results in less time. 12 In the present article, the patient was a 13-year-5-months-old female in post menarche, CS4 (CVS) and 16-year-old skeletal age, according to a hand-wrist film. Her growth spurt has passed, and she is skeletally mature. At this age, facemask treatment alone would not provide the skeletal improvements, but most likely would have dental effects.

Percentage of jackscrew B-A C-B C-A B-A
CBCT images at post-expansion confirmed the skeletal expansion in the midpalatal suture at the level of the first molars was 5.7 mm, which was 71% of the jackscrew expansion; the first molars tipped 2.0° buccally, and alveolar bone inclination changed 4.0° palatally (Figs 3A-F and Table 2). Garrett et al. 13 reported 38% of skeletal expansion in the first molar region with the Hyrax RPE in patients (mean age = 13.8 years). A mean of 52.82% (4.33 mm) midpalatal suture opening at the first molars Matsumoto K, Tanna N -Maxillary protraction and vertical control utilizing skeletal anchorage for midfacial-maxillary deficiency 25 was obtained in children (mean age = 9.9 years) who were treated with a bonded RPE. 14  In summary, bone-or tissue-borne expanders produced greater orthopedic effects and fewer dentoalveolar side effects, compared to the tooth-borne expanders. TAD-Haas RPE showed excellent results for maximizing the skeletal changes and minimizing the dentoalveolar compensations. As a long-term stability after expansion, RPE treatment did not influence the sagittal position of the apical jaw bases or the facial vertical dimension. 16 RPE treatment alone has shown that there is downward and forward movement of the maxilla. [17][18][19] The mean SNA, ANB, mandibular plane angle (MP.SN) increased by 0.35°, 1.00°, 1.72°, respectively. 19 As dental changes, average decreases of the U1.SN and IMPA were reported as 0.43° and 0.59°, respectively. 19 Therefore, RPE can be beneficial in skeletal Class III patients for promoting maxillary forward movement and incisal uprighting. The results for this post-growth-spurt patient were compatible or even preferable to a previous study 29 in which 10-yearold children were treated with TAD-RPE and facemask.
Once the maxillary expansion and overcorrection of the maxillary protraction to an end-to-end Class II molar relationship was completed, the TADs for the RPE were utilized for con-