THE DIAGNOSTIC RELIABILITY OF THE FRANKFORT HORIZONTAL PLANE, EVALUATED BY 3D CEPHALOMETRY

F. Cecchetti¹, M. Di Girolamo¹, L. Baggi², and D. Mazza²

¹Department of clinical sciences and translational medicine, Tor Vergata University, Roma, Italy
²Department of social dentistry and gnathological rehabilitation, National Institute for Health, Migration and Poverty (NIHMP), Roma, Italy

Correspondence to:
Dario Mazza, DDS
Department of social dentistry and gnathological rehabilitation,
National Institute for Health, Migration and Poverty (NIHMP), Roma, Italy
e-mail: mzzdra@hotmail.com

Received: 15 March 2018 Accepted: 10 May 2018

2038-4106 (2018) Copyright © by BIOLIFE This publication and/or article is for individual use only and may not be further reproduced without written permission from the copyright holder. Unauthorized reproduction may result in financial and other penalties Disclosure: all authors report no conflicts of interest relevant to this article.

ABSTRACT

Many maxillofacial malformations can modify the Frankfort horizontal plan making it unusable in orthodontic clinical diagnosis. This study aims to evaluate the position of the cephalometric points that determine the Frankfort horizontal plane on individualised craniofacial CT reconstructions using the foramen occipital line (Basion-Opisthion) on the midline sagittal axis as a reference. Thirty patients (15 males and 15 females aged between 10 and 76, mean of 36.4 years) were selected among those undergoing maxillofacial CT. Three multiplanar reconstructions were performed; the first was positioned at the craniofacial midline level, and a line was drawn passing from the Basion and Opisthion craniometric points; the second and third reconstructions were positioned on the right and left side, respectively, with a postero-anterior and lateromedial inclination to observe two parasagittal planes suitably inclined on which a line was drawn between the craniometric points Porion and Orbitale of the respective hemiface. The following parameters were evaluated: 1. angles between Basion-Opisthion and right and left Frankfort horizontal plane and the difference between them; 2. the minimum vertical distance on the individualised multiplanar reconstructions between the Porion and Orbitale points on the left and the right side, and the line passing through Basion-Opisthion; 3. the difference between the minimum vertical distance of the right and left Porion and Orbitale; 4. the difference between the minimum vertical distance of the right and left Orbitale point. The difference between the left and right Frankfort horizontal plane ranged from 0° to 7° with a mean value of 2°23’. The difference between the vertical position of the right and left Porion points ranged between 0 and 12 mm, with a mean value of 3.35 mm. The difference between the vertical position of the right and left Orbitale points ranged between 0 and 7.5 mm, with a mean value of 2.35 mm. The Frankfort horizontal plane is questionable in patients with craniofacial asymmetries and malformations.

KEYWORDS: cephalometry, orthodontics, CT, malformation, asymmetry