Herbst treatment with mandibular cast splints--revisited.

Area of Science:

• Orthodontics
• Craniofacial Growth and Development
• Biomaterials in Dentistry

Background:

• The Herbst appliance is widely used for correcting Class II malocclusions.
• Reduced mandibular splint (RMS) Herbst appliances offer an alternative to traditional total mandibular cast splints (TMS).
• Understanding the specific dento-skeletal effects and anchorage changes associated with RMS-Herbst treatment is crucial for clinical decision-making.

Purpose of the Study:

• To evaluate the dento-skeletal treatment effects of RMS-Herbst appliances.
• To quantify the amount of anchorage loss during RMS-Herbst treatment.
• To compare these outcomes with those of TMS-Herbst treatment.

Main Methods:

• A retrospective analysis of 100 Class II patients treated with RMS-Herbst appliances.
• Cephalometric measurements of lower incisor inclination, sagittal occlusion, and dental cast analysis were performed pre- and post-treatment.
• Comparison with a historical control group treated with TMS-Herbst appliances.

Main Results:

• RMS-Herbst treatment resulted in significant lower incisor proclination (12.9° ± 4.6°), which was 3.6° greater than in the TMS group.
• Lower incisor proclination increased with patient age during treatment.
• An average increase of 1.8 mm in lower arch space was observed, with 62% of patients showing interproximal space opening between premolars and molars.

Conclusions:

• RMS-Herbst appliances lead to increased lower incisor proclination compared to TMS-Herbst appliances.
• RMS-Herbst treatment is associated with a greater overall amount of anchorage loss.
• Clinicians should consider these findings when selecting Herbst appliance designs for Class II correction.