Clinical Trial: Crossbow Versus Forsus Springs in Mild to Moderate Class II Malocclusion Cases

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Interventional

Official Title: 3D Changes Comparing the Crossbow Appliance and Later Full Fixed Brackets Against Simultaneous Use of Full Fixed Brackets Plus Forsus Springs Among Mild to Moderate Class II Malo

Brief Summary:

Class II malocclusion (mismatch between the upper and lower jaw in which the lower jaw appears to be smaller from a profile point of view) are common in the general population. Around 1/3 of the population have some degree of this skeletal/dental problem and it is one frequent reason why patients decide to undergo orthodontic treatment. Treatment alternatives will basically depend on the facial skeletal development of the patient and also on the magnitude of the skeletal/dental discrepancy.

For patients that are not yet fully skeletal mature, the treatment of mild to moderate Class II malocclusion involves a combination of a small skeletal growth modification effect and more significant dental movements. For skeletal mature individuals with a severe mismatch, the treatment usually involves jaw surgery to fully correct the malocclusion. For less severe cases orthodontic camouflage exclusively done by orthodontic movements is an option.

If the case is not severe enough to warrant a surgical approach there are several treatment alternatives. One of the most commonly used options is the use of orthodontic loaded springs that apply forces through brackets and arch wires bonded into the teeth so that the teeth will interrelate better.

A different alternative was proposed some years ago. The Xbow (spelled Crossbow) appliance differs from the above-proposed option in that no brackets are bonded or arch wires used. The orthodontic springs are applied to a metal framework cemented on some upper and lower teeth. Once the skeletal/dental problem is believed to have been significantly improved, fine tuning of the remaining dental problems is managed with brackets and arch wires. The theoretical advantage of such a design is that adverse effects, such as root resorption and decalcificati

Detailed Summary:

Background

Class II malocclusion is a common orthodontic problem that requires comprehensive treatment planning. Treatment of Class II malocclusion is frequently initiated in mid to late mixed dentition whereby crowding and/or an increased over jet becomes alarming to patients and parents. Earlier correction of Class II abnormalities could be suggested in patients with significant occlusion discrepancies, increased risk of trauma to protruding upper incisors and impairment of mastication functions.

Among the available Class II correctors, cemented/fixed options are gaining popularity. Systematic reviews have shed some light on what fixed Class II correction devices appear to produce during treatment of mild to moderate Class II malocclusion. Short-term changes were a combination of skeletal and dental modifications. Skeletal modifications include both maxillary restriction and mandibular repositioning, and dental effects usually consist of inclination of mandibular incisors and maxillary molar distal movement.

Cephalometric analysis is a valuable tool used for diagnosis and treatment planning for dental malocclusion and underlying skeletal discrepancies. In view of the fact that a malocclusion is a product of an interaction between the alignment of the erupting teeth in their basal bone and the skeletal position of the basal bone itself, cephalometric analysis are used to evaluate dentoalveolar proportions and elucidate the anatomic basis for both jaw and tooth related abnormalities in the sagittal plane.

The Xbow appliance is a recently introduced orthodontic device that is used in late mixed or early permanent dentition before full fixed orthodontic treatment is initiated. Its main goal is to rapidly correct/improve the oc
Sponsor: University of Alberta, Graduate Orthodontic Program

Current Primary Outcome: Facial soft tissue, dental and skeletal changes [ Time Frame: 24 months ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

• Root resorption [ Time Frame: 24 months ]
  Evaluation of the magnitude of external root resorption as quantified/qualified from the CBCT data.
• Enamel decalcification [ Time Frame: 24 months ]
  Enamel decalcification as clinically determined by observing and touching the enamel surfaces of teeth.

Original Secondary Outcome: Same as current

Information By: University of Alberta, Graduate Orthodontic Program

Dates:
Date Received: February 7, 2012
Date Started: October 2012
Date Completion: December 2019
Last Updated: May 3, 2017
Last Verified: May 2017