Long-term effects of lateral nasal wall anchored facemasks compared with tooth-borne facemasks.

INTRODUCTION: This study investigated the long-term effect and stability of skeletally anchored facemasks (SAFMs) with lateral nasal wall anchorage compared with conventional tooth-borne facemasks (TBFMs) in growing patients with a Class III relationship. METHODS: A total of 180 subjects treated with SAFMs (n = 66) and TBFMs (n = 114) were screened. Thirty-four subjects were qualified and grouped into the SAFM group (n = 17) and TBFM group (n = 17). Lateral cephalograms were taken at the initial observation, after the protraction, and at the final observation. RESULTS: Greater advancement of the maxilla was attained with SAFM than with TBFM after protraction (initial observation - after the protraction) (P <0.05). In particular, advancement of the midfacial area (SN-Or) was prominent and maintained after the postpubertal stage (P <0.05). The intermaxillary relationship was also improved (ANB, AB-MP) (P <0.05), and greater counterclockwise rotation of the palatal plane (FH-PP) was observed in the SAFM group compared with the TBFM group (P <0.05). CONCLUSIONS: Compared with TBFM, the orthopedic effects of SAFM were greater in the midfacial area. The palatal plane had a greater counterclockwise rotation in the SAFM group than in the TBFM group. Maxilla (SN-Or), intermaxillary relationship (APDI), and palatal plane angle (FH-PP) demonstrated a significant difference between the 2 groups after the postpubertal stage.

Skeletal and dentoalveolar effects of different types of microimplant-assisted rapid palatal expansion.

Objective: To evaluate the following null hypothesis: the skeletal and dentoalveolar expansion patterns in the coronal and axial planes are not different with two different types of microimplant-assisted rapid palatal expansion (MARPE) systems. Methods: Pretreatment (T0) and post-MARPE (T1) cone-beam computed tomography (CBCT) images of 32 patients (14 males and 18 females; mean age, 19.37) were analyzed. We compared two different MARPE systems. One MARPE system included the maxillary first premolars, maxillary first molars, and four microimplants as anchors (U46 type, n = 16), while the other included only the maxillary first molars and microimplants as anchors (U6 type, n = 16). Results: In the molar region of the U6 and U46 groups, the transverse expansion at the midnasal, basal, alveolar, and dental levels was 2.64, 3.52, 4.46, and 6.32 mm and 2.17, 2.56, 2.73, and 5.71 mm, respectively. A significant difference was observed in the posterior alveolar-level expansion (p = 0.036) and posterior basal-bone-level expansion (p = 0.043) between the groups, with greater posterior skeletal and alveolar expansion in the U6 group. Conclusions: Compared with the U46 group, the U6 group showed greater posterior expansion at the alveolar and basal-bone levels, with an almost parallel split. Both groups showed a pyramidal expansion pattern in the coronal view.