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Related Experiment Video

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Studying Orthodontic Tooth Movement in Mice

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Facial flatness indices: application in orthodontics.

Chimène Chalala¹, Maria Saadeh^1,2, Fouad Ayoub²

¹Department of Orthodontics and Dentofacial Orthopedics, Lebanese University and American University of Beirut, Beirut, Lebanon.

|May 31, 2019

Summary

Facial flatness indices, particularly the zygomaxillary index, show variation in different malocclusions. This index may aid in assessing maxillary width in Class II and Class III cases.

Keywords:

Anthropology Facial flatness indices Malocclusions Orthodontics

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Area of Science:

Anthropology
Orthodontics
Craniofacial analysis

Background:

Facial flatness indices historically used in anthropology to differentiate populations.
Previous research has not extensively evaluated these indices within orthodontic contexts.

Purpose of the Study:

To evaluate the utility of facial flatness indices in orthodontics.
To determine variations in facial flatness indices across different malocclusions, age groups, and sexes.

Main Methods:

Analysis of 322 digitized cone beam computed tomography (CBCT) radiographs.
Measurement of three facial indices (frontal, simotic, zygomaxillary) and three transverse distances.
Comparison of measurements between different malocclusion groups, age cohorts, and sexes.

Main Results:

The zygomaxillary index was significantly higher in Class II and lower in Class III malocclusions compared to Class I.
Frontal and nasal flatness did not significantly characterize sagittal malocclusions.
No significant differences in facial flatness indices were found between sexes or between growing and non-growing patients.

Conclusions:

The sagittal position of the subspinale point (A point) relative to zygomaxillary width is key for assessing facial flatness.
The zygomaxillary index can assist in proportionally evaluating maxillary width in relation to sagittal position for Class II and Class III malocclusions.