Deformation of the circummaxillary sutures during acute micro-implant assisted rapid palatal expansion and tooth-supported expansion: An ex vivo study

In-silico evaluation of orthodontic miniscrew-assisted rapid palatal expanders for patients with various stages of skeletal maturation

INTRODUCTION

This study aimed to use a finite element method to assess the stress on the miniscrews, skeletal and dental changes resulting from maxillary expansion using either a tooth-bone-borne (TBB) or a bone-borne (BB) device on patients with various skeletal maturation.

METHODS

Two types of expanders were modeled using SolidWorks. The design of the 2 expanders was similar, with the exception that the BB appliance lacked support for teeth (rods and bands). Both were placed on the palatal bones with the help of 4 miniscrews as bony anchorage. Five skeletal maturation stages were examined using suture maturation classification by Angelieri. A lateral displacement of 0.2 mm was applied to simulate 1 turn of jackscrew per day. The dental and skeletal changes from the treatment were quantified.

RESULTS

Stage A sutural maturation exhibited the greatest skeletal movement (0.13 mm/d) with a V-shaped displacement pattern. Stages B and C exhibited a more parallel expansion pattern. Stages D and E exhibited the least amount of skeletal movement with either device. Compared with the BB device, TBB demonstrated greater dental displacement. On average, the BB device exhibited a skeletal-to-dental expansion ratio of 70% from stage A to C compared with 49% with the TBB device.

CONCLUSIONS

BB device showed more skeletal displacement than TBB, and the latter showed more dental side effects, particularly during stages B and C. The miniscrew-assisted rapid palatal expansion appliance was effective with sutural maturation stages A to C using the classification by Angelieri with a more parallel separation of the midpalatal sutures in stages B and C.

Intermaxillary elastics on skeletal anchorage and MARPE to treat a class III maxillary retrognathic open bite adolescent: A case report

Class III malocclusion when accompanied with transverse and vertical maxillomandibular discrepancies such as posterior crossbite and vertical open bite leads to complicated orthodontic treatment. Proper diagnosis and treatment planning are important in such patients for a successful orthodontic outcome. A common treatment approach for patients with class III malocclusion is to wait for the completion of growth and plan orthognathic surgery in conjunction with orthodontic treatment. However, performing no treatment and waiting for growth to be completed during teen years could lead to negative effects on the patient's self-esteem. In such cases, a non-surgical option with skeletal anchorage could be used to correct the malocclusion without surgical intervention. This case report shows that in patients with severe class III malocclusion, skeletal anchorage can be used for the correction of anterior crossbite with intermaxillary elastics.