Nonsurgical miniscrew-assisted rapid maxillary expansion results in acceptable stability in young adults

Abstract

Objective: To evaluate the stability of nonsurgical miniscrew-assisted rapid maxillary expansion (MARME) in young adults with a transverse maxillary deficiency.

Materials and methods: From a total of 69 adult patients who underwent MARME followed by orthodontic treatment with a straight-wire appliance, 20 patients (mean age, 20.9 ± 2.9 years) with follow-up records (mean, 30.2 ± 13.2 months) after debonding were selected. Posteroanterior cephalometric records and dental casts were obtained at the initial examination (T0), immediately after MARME removal (T1), immediately after debonding (T2), and at posttreatment follow-up (T3).

Results: Suture separation was observed in 86.96% of subjects (60/69). An increase in the maxillary width (J-J; 1.92 mm) accounted for 43.34% of the total expansion with regard to the intermolar width (IMW) increase (4.43 mm; P < .001) at T2. The amounts of J-J and IMW posttreatment changes were -0.07 mm (P > .05) and -0.42 mm (P = .01), respectively, during retention. The postexpansion change in middle alveolus width increased with age (P < .05). The postexpansion change of interpremolar width (IPMW) was positively correlated with the amount of IPMW expansion (P < .05) but not with IMW. The changes of the clinical crown heights in the maxillary canines, first premolars, and first molars were not significant at each time point.

Conclusions: Nonsurgical MARME can be a clinically acceptable and stable treatment modality for young adults with a transverse maxillary deficiency.

Keywords: Adults; MARME; Stability; Transverse maxillary deficiency.

Figure 1.

Study flow chart.

Figure 2.

Fixation of the miniscrew-assisted rapid maxillary expansion (MARME) device and periapical views before and after expansion. (A) A MARME appliance. (B) Before expansion. (C) After 2 weeks of expansion, a diastema caused by splitting of the midpalatal suture can be observed.

Figure 3.

Skeletal and dental measurements. (A) N-N, nasal cavity width; J-J, maxillary width; Ma-Ma, middle alveolus width. (B) ICW, intercanine width; IPMW, interpremolar width; IMW, intermolar width; CH3, clinical crown height of the canine; CH4, clinical crown height of the first premolar; CH6, clinical crown height of the first molar.

Figure 4.

Changes over time after MARME in the skeletal and dental measurements. N-N, nasal cavity width; J-J, maxillary width; Ma-Ma, middle alveolus width; ICW, intercanine width; IPMW, interpremolar width; IMW, intermolar width; T0, at the initial examination; T1, immediately after MARME removal; T2, immediately after debonding; T3, at posttreatment. An asterisk means that there was a significant difference between each time point and T0. Error bar, standard deviation.

Figure 5.

Schematic diagram after MARME. T0, at the initial examination; T2, immediately after debonding; T3, at posttreatment.

Figure 6.

Changes over time after MARME in the clinical crown heights of the canine (CH3), first premolar (CH4), and first molar (CH6). T0, at the initial examination; T2, immediately after debonding; T3, at posttreatment. The changes in clinical crown heights of canines (CH3), first premolars (CH4), and first molars (CH6) were not significantly different at each time point. Error bar, standard deviation.