Effects of facemask treatment anchored with miniplates after alternate rapid maxillary expansions and constrictions; a pilot study

Abstract

Objective: To describe the dentoskeletal and soft tissue effects of facemask treatment anchored with miniplates after alternate rapid maxillary expansions and constrictions (Alt-RAMEC) in maxillary retrusion patients.

Materials and methods: The sample consisted of 15 patients with a mean skeletal age of 11.6 ± 1.59 years undergoing 8 weeks of Alt-RAMEC followed by maxillary protraction. Three hundred fifty to 400 g of force per side was applied to the facemask from the titanium miniplates inserted on the lateral nasal wall of the maxilla. Total treatment time was 9.9 ± 2.63 months. Treatment changes were evaluated cephalometrically and analyzed by means of the dependent t-test and the Wilcoxon signed rank test.

Results: The miniplates withstood the orthopedic forces exerted during the treatment. Cephalometric findings showed that the maxilla moved forward by 2 mm, with an 0.8° counterclockwise rotation and without maxillary incisor movement. The mandible moved slightly in a downward and backward direction (1.2°). The inclinations of the mandibular incisors decreased significantly (2°). Statistically significant increases were observed in the vertical dimension (1°-1.3°). Soft tissue changes were more marked in the upper lip and soft tissue pogonion than in the lower lip.

Conclusions: This treatment approach can offer an advantage for correcting mild/moderate maxillary retrusion in Class III patients.

Figure 1

Titanium miniplate after attachment to the lateral nasal wall of the maxilla.

Figure 2

Panoramic radiograph after surgery.

Figure 3

Cephalometric measurements used in the study: (a) X, horizontal reference plane; Y, vertical reference plane; 1, palatal plane angle (ANSPNS-SN) (°); 2, SNA (°); 3, maxillary depth (FH-NA) (°); 4, McNamara (A-Nperp) (mm); 5, convexity (A-NPog) (mm); 6, A-Y (mm); 7, ANS-X (mm); 8, PNS-X (mm); and 9, Maxillary length (Co-A) (mm). (b) 10, SNB (°); 11, Facial depth (FH-NPog) (°); 12, Pog-Y (mm); 13, B-Y (mm); and 14, Mandibular length (Co-Gn) (mm). (c) 15, ANB (°); 16, Witts appraisal (mm). (d) 17, GoGn-SN (°); 18, FMA (°); 19, Lower facial height (ANS-Xi-Pm) (°); 20, N-Me (mm); and 21, ANS-Me (mm). (e) 22, U1-SN (°); 23, U1-FH (°); 24, U1-NA (°); 25, IMPA (°); 26, FMIA (°); 27, L1-NB (°); 28, U6m-Y (mm); 29, overjet (mm); and 30, overbite (mm). (f) 31, Pr-Y (mm); 32, Ls-Y (mm); 33, Ls-E (mm); 34, Li-Y (mm); 35, Li-E (mm); and 36, sPog-Y (mm).

Figure 4

Bone apposition around the miniplate.