Evaluation of the changes of orbital cavity volume and shape after tooth-borne and bone-borne rapid maxillary expansion (RME)

Antonino Lo Giudice,Manuel Lagravère,Carmelo Nicotra,Lorenzo Rustico,Vincenzo Ronsivalle,Cristina Grippaudo

doi:10.1186/s13005-020-00235-1

Abstract

ObjectiveTo assess and compare volumetric and shape changes of the orbital cavity in patients treated with tooth-borne (TB) and bone-borne (BB) rapid maxillary expansion (RME).Study designForty adolescents with bilateral maxillary cross-bite received tooth-borne (TB group = 20; mean age 14.27 ± 1.36 years) or bone-borne (BB group = 20; mean age of 14.62 ± 1.45 years) maxillary expander. Cone-beam computed tomography (CBCT) were taken before treatment (T1) and 6-month after the expander activation (T2). Volumetric and shape changes of orbital cavities were detected by referring to a specific 3D digital technology involving deviation analysis of T1/T2 CBCT-derived models of pulp chamber. Student’s t tests were used to 1) compare T1 and T2 volumes of orbital cavities in TB and BB groups, 2) compare volumetric changes and the percentage of matching of 3D orbital models (T1-T2) between the two groups.ResultsBoth TB and BB groups showed a slight increase of the orbital volume (0.64 cm3 and 0.77 cm3) (p < 0.0001). This increment were significant between the two groups (p < 0.05) while no differences were found in the percentage of matching of T1/T2 orbital 3D models (p > 0.05). The areas of greater changes were detected in the proximity of the frontozygomatic and frontomaxillary sutures.ConclusionTB-RME and BB-RME would not seem to considerably affect the anatomy or the volume of the orbital cavity in adolescents.

Highlights

Rapid Maxillary expansion (RME) is the most efficient treatment for the correction of maxillary transverse deficiency [1]
Previous studies based on finite element analyses (FEM) showed that RME increases the stress levels on neighboring structures and on the cranial base due to the cumulative forces released during the repeated activations of the expansion screw [4, 5]
Previous evidence suggested that maxillary expansion may alter the volume of the orbital cavity [10], this aspect has not been studied extensively nor it has been determined if volumetric changes of the orbital cavity caused by RME may interfere with its normal growth pattern and physiology

Summary

Introduction

Rapid Maxillary expansion (RME) is the most efficient treatment for the correction of maxillary transverse deficiency [1]. Concerning the circummaxillary structures, post-treatment changes were found at the level of the zygomatic process, the frontozygomatic suture and the frontal process of the maxilla [1, 7,8,9], all these structures being part of the orbital cavity In this regard, previous evidence suggested that maxillary expansion may alter the volume of the orbital cavity [10], this aspect has not been studied extensively nor it has been determined if volumetric changes of the orbital cavity caused by RME may interfere with its normal growth pattern and physiology. This aspect could be of clinical relevance considering that a positive correlation was found between the increment of orbital volumes and the degree of dysmorphology, enophtalmos, orbitopathy [11]

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Discussion

Conclusion