Changes in alveolar bone support induced by the Herbst appliance: a tomographic evaluation

Area of Science:

• Orthodontics
• Dental Imaging
• Periodontology

Background:

• The Herbst appliance is used to correct Class II malocclusions.
• Alveolar bone changes around teeth are a concern during orthodontic treatment.
• Cone-beam computed tomography (CBCT) is a valuable tool for assessing bone dimensions.

Purpose of the Study:

• To evaluate alveolar bone loss around mandibular incisors after Herbst appliance treatment.
• To assess changes in vertical alveolar bone level and thickness of mandibular incisors.

Main Methods:

• 23 patients with Class II, Division 1 malocclusion treated with the Herbst appliance were studied.
• CBCT scans were taken before (T0) and after (T1) treatment.
• Alveolar bone thickness and vertical bone level of mandibular incisors were measured at different levels.

Main Results:

• No significant changes in vertical alveolar bone level were observed.
• Alveolar bone thickness decreased significantly on the buccal side (B1, B2, B3) and total thickness at the crest (T1).
• A significant increase in lingual bone thickness at the midroot level (L2) was noted, with all changes < 0.2 mm.

Conclusions:

• The Herbst appliance is associated with alveolar bone loss on the buccal surface of mandibular incisors.
• Observed bone changes were minimal and lacked clinical significance.
• CBCT imaging confirmed these findings, highlighting the need for careful monitoring.