Dental arch changes comparison between expander with differential opening and fan-type expander: a randomized...

Area of Science:

• Orthodontics
• Craniofacial Development
• Pediatric Dentistry

Background:

• Posterior crossbite is a common malocclusion in children.
• Maxillary expansion is a key treatment for posterior crossbite.
• Different expander designs may yield varied outcomes.

Purpose of the Study:

• To compare the effectiveness of the expander with differential opening (EDO) and the fan-type expander (FE) in correcting posterior crossbite.
• To evaluate dentoalveolar and skeletal changes induced by EDO and FE during rapid maxillary expansion.

Main Methods:

• A two-arm parallel randomized controlled trial involving 48 patients aged 7-11 years.
• Patients were randomly assigned to EDO or FE treatment groups.
• Digital dental models were used to assess crossbite correction and maxillary arch changes before and after treatment.

Main Results:

• The EDO group achieved 100% crossbite correction, compared to 75% in the FE group.
• EDO resulted in greater increases in maxillary intermolar width, while FE showed greater increases in intercanine width.
• Both expanders altered maxillary arch shape, with FE expanding the anterior region and EDO expanding the posterior region.

Conclusions:

• EDO and FE produce distinct maxillary arch width and shape changes.
• EDO is more effective in correcting posterior crossbite and expanding the posterior maxilla.
• FE is more effective in expanding the anterior maxilla.