Changes in occlusion and condylar positioning during retention with a gnathologic positioner

Area of Science:

• Orthodontics
• Gnathology
• Dental Occlusion

Background:

• Gnathologic requirements are crucial for functional occlusion.
• Orthodontic treatment aims to achieve stable and functional occlusal relationships.
• The role of gnathologic positioners in post-orthodontic stability requires investigation.

Purpose of the Study:

• To evaluate if orthodontic cases can meet gnathologic requirements.
• To assess the stability of centric relation (RCP) and intercuspal position (ICP) after orthodontic treatment.
• To determine the efficacy of a gnathologic positioner in maintaining occlusal stability.

Main Methods:

• Models of 10 adolescent orthodontic patients were analyzed.
• Mounted models were evaluated at specific intervals over one year post-band removal.
• Patients wore a gnathologic positioner throughout the study period.
• Condylometry was used to measure discrepancies between RCP and ICP in three planes.
• The spatial diagonal was computed to quantify overall occlusal slide.

Main Results:

• Continuous wear of the gnathologic positioner significantly reduced the slide in centric between RCP and ICP.
• After 3 months of continuous wear, RCP and ICP became nearly identical.
• Slight increases in the slide were observed after 7 months of nighttime-only positioner use.
• The spatial diagonal increased primarily due to sagittal and vertical slide changes; lateral slide remained constant.

Conclusions:

• Gnathologic positioners can effectively help orthodontic patients achieve gnathologic requirements.
• Continuous wear is most effective in minimizing occlusal slide and maintaining RCP-ICP congruence.
• Intermittent nighttime use may lead to a slight regression in occlusal stability over time.