Exploring the mylohyoid area as a reference for three-dimensional digital mandibular superimposition.

Area of Science:

• Orthodontics
• Dental Imaging
• Biomedical Engineering

Background:

• Accurate quantification of tooth movements is crucial in orthodontics.
• Cone Beam Computed Tomography (CBCT) is established for maxillary superimposition, but mandibular superimposition methods require further definition.
• Traditional methods include teleradiographs and casts, with limitations in 3D analysis.

Purpose of the Study:

• To evaluate the accuracy of the mylo-hyoid area as a reference landmark for three-dimensional (3D) superimposition of mandibular Digital Dental Casts (DDC).
• To compare 3D DDC superimposition using the mylo-hyoid area with conventional 2D lateral cephalograms for assessing orthodontic tooth movement.

Main Methods:

• A comparative study involving 30 orthodontic patients.
• 3D mandibular overlays were created using the mylo-hyoid area as a reference.
• Coordinates of molars and incisors from 3D superimposition were compared with those from 2D lateral cephalograms using paired t-tests.

Main Results:

• No statistically significant differences were found between the mylo-hyoid area-based 3D DDC superimposition and the 2D lateral cephalogram method.
• Sagittal and vertical displacements of lower first molars and central incisors showed comparable results between the two methods.

Conclusions:

• The mylo-hyoid area is a reliable and accurate landmark for 3D superimposition of the mandible in orthodontic treatment.
• This 3D superimposition method is applicable to patients with conventional orthodontic records.
• Further research on larger populations and diverse subgroups is recommended.