Condylar Reshape in Orthognathic Surgery: Morphovolumetric and Densitometric Analysis Based on 3D Imaging and Digital Workflow

Abstract

Background Condylar remodelling (CR) is a complex of phenomena that generates in response of the temporo-mandibular joint to forces and stress to maintain a morphological, functional and occlusal homeostasis. The most worrying aspect of the condylar reshape is the condylar resorption which implies fast loss of vertical dimension (>6% of pre-surgical value), mandibular retraction and open bite with preserved articular function. Materials and Methods Six parameters were analysed to study the condyles of twelve patients that underwent orthognathic surgery. The digital workflow was then described to make it reproducible enabling a more in-depth study of the reshaping processes that involving the condyle after a great stress like the surgery. Results The results of our study showed many statistically significant variations of the studied parameters. In all patients, it was noticed a decreased bone density (p = 0,002 per side). Objectives The aim of our study, with the aid of the contemporary 3D imaging and digital modelling and workflow technologies, is to investigate and analyse quantitatively and qualitatively the adaptative processes occurring in CR following bimaxillary repositioning. To the best of our knowledge, this is the only paper that investigates the CR considering six different variables at once.

Condylar Positional Changes in Skeletal Class II and Class III Malocclusions after Bimaxillary Orthognathic Surgery

“…Bone changes in the condylar head after an orthognathic surgery is an adaptative reply to the mechanical load and stress in the TMJ with changes in the position of the condyle; in some cases, this can develop a pathological condition [38]. Condylar resorption is a clinical condition with a prevalence between 1% to 31%, which is mainly presented in female patients with class II and a high mandibular plane [39].…”

Anatomorphological variations of the temporomandibular joint after orthognathic surgery: A descriptive study.

“…The TMJ is a dynamic structure capable of adapting to internal and external stimuli due to its anatomical and histological characteristics 5,12 . In the present study, bone remodelling of the condylar cortex was observed in all patients.…”

“…The temporomandibular joint (TMJ) is a dynamic structure capable of adapting to mechanical stress to preserve the stomatognathic system's morphological, functional, and occlusal homeostasis [1][2][3] . It represents a fundamental component in orthognathic surgery because, when performing the movements of the bone segments, it must adapt to achieve satisfactory immediate and long-term results [1][2][3][4][5] . However, pathological condylar resorption occurs when faced with excessive mechanical stress or when the host's adaptive capacities are diminished or exceeded [6][7][8] .…”