Soft tissue response to mandibular advancement using 3D CBCT scanning

Abstract

This prospective longitudinal study assessed the 3D soft tissue changes following mandibular advancement surgery. Cranial base registration was performed for superimposition of virtual models built from cone beam computed tomography (CBCT) volumes. Displacements at the soft and hard tissue chin (n=20), lower incisors and lower lip (n=21) were computed for presurgery to splint removal (4-6 week surgical outcome), presurgery to 1 year postsurgery (1-year surgical outcome), and splint removal to 1 year postsurgery (postsurgical adaptation). Qualitative evaluations of color maps illustrated the surgical changes and postsurgical adaptations, but only the lower lip showed statistically significant postsurgical adaptations. Soft and hard tissue chin changes were significantly correlated for each of the intervals evaluated: presurgery to splint removal (r=0.92), presurgery to 1 year postsurgery (r=0.86), and splint removal to 1 year postsurgery (r=0.77). A statistically significant correlation between lower incisor and lower lip was found only between presurgery and 1 year postsurgery (r=0.55). At 1 year after surgery, 31% of the lower lip changes were explained by changes in the lower incisor position while 73% of the soft tissue chin changes were explained by the hard chin. This study suggests that 3D soft tissue response to mandibular advancement surgery is markedly variable.

Clinical effectiveness and cost-effectiveness results from the randomised controlled Trial of Oral Mandibular Advancement Devices for Obstructive sleep apnoea–hypopnoea (TOMADO) and long-term economic analysis of oral devices and continuous positive airway pressure

“…It has been suggested that future meta-analyses distinguish between trials of non-adjustable MADs and those using aMAD. 209,210 From the 2006 Cochrane analysis, considering only trials comparing CPAP with aMADs moved the sleepiness (ESS score) effect size in favour of MADs, but not significantly. 33 We considered performing a similar subgroup analysis when updating the meta-analysis.…”

3D Assessment of Orthognathic Surgical Outcomes

“…A second method performs a fully automated, operator-independent registration of scans from two time points using the gray scale intensity voxel by voxel for the cranial base region of nongrowing patients (Cevidanes et al, 2005;Figure 22.2). This technique has a high level of reliability and reproducibility , and several recently published surgical orthodontic studies have used this superimposition technique to demonstrate treatment outcomes (Cevidanes et al, 2007;Carvalho Fde et al, 2010;Almeida et al, 2011;Motta et al, 2011; see also Chapter 21).…”

“…One is based on linear and angular measurements (Jung et al, 2009;Kim et al, 2010Kim et al, , 2011Park et al, 2012a) that apply the concepts used routinely in 2D cephalometry to 3D images. The second method is based on the use of iterative closest point algorithms (Cevidanes et al, 2007;Carvalho Fde et al, 2010;Almeida et al, 2011;Motta et al, 2011) that analyze the smallest displacements between two structures but do not take into account the shape being measured. The third and most recent method is called shape correspondence (Figure 22.3).…”

Three-dimensional Assessment of Facial Soft Tissue after Orthognathic Surgery in Patients with Skeletal Class III and Asymmetry

“…Several techniques [3][4][5][6][7][8], such as three-dimensional (3D) photogrammetry, laser surface scanning, and cone-beam computed tomography (CBCT), have been developed for 3D analysis of soft-tissue. However, patients' heads are usually held with a strap on the forehead or a chin support, or patients are lying down when taking CBCT, which causes deformation of soft tissue of the forehead, chin, or lips.…”