Is palato-premaxillary subduction a characteristic of Binder's syndrome?

Abstract

Objectives: Binder's syndrome is a rare malformative syndrome, defined clinically. CT study of a patient with this morphotype found palato-premaxillary joint subduction on a sagittal slice. The objective of the present study was to analyze this joint in a control population free of Binder's syndrome.

Material and methods: Fifty adult Caucasian patients who had undergone sinus CT scan between 2013 and 2016, showing normal nasolabial angle and with good visualization of the palato-premaxillary joint on a single sagittal slice, were selected. Joint analysis by 3 observers classified the patients in 2 groups: A, showing approximation between primary and secondary palate, and S, showing subduction. Alongside the observers' subjective analysis, the following parameters were compared: posterior palato-premaxillary angle (A₁), superior palato-premaxillary angle A₂, and the distance (d) of the premaxilla above the secondary palate.

Results: Fifty patients were included: 43 in group A and 7 in group S. A₁ angle differed significantly between groups: 111.95±10.22° in group A, versus 130.53±10.0° in group S; P=0.0015. Values for A₂ and d did not differ according to group.

Conclusion: Two forms of palato-premaxillary joint, showing approximation or subduction, were found in the control population. Approximation was more frequent. Palato-premaxillary subduction does not in itself characterize Binder's syndrome.

Keywords: Binder's syndrome; Evo-devo theory; Incisive canal; Nasolabial angle; Palato-premaxillary joint.