Biomechanical analyses of common suspension sutures in primary cleft lip rhinoplasty

Abstract

Background For a better understanding of common suspension sutures during primary cleft lip nasal rhinoplasty, the biomechanical consequences of those sutures need to be demonstrated. Methods A finite element model of the infant specimen was established. The closure of cleft lip and four different specific suspension sutures were simulated by loading different forces on the model: 1. F1 to simulate the suture fastening both medial crura together; 2. F2 to simulate the suture which sewed both medial crura and the non-cleft-side upper lateral cartilage together; 3. F3 to simulate the suture elevating the alar cartilage cranially; 4. F4 to simulate the suture elevating the alar cartilage superiorly. The deformation and stress distribution consequent to each maneuver were analyzed in details. Results The deviation of columella was restored through the closure of cleft lip. Different suspension sutures had different biomechanical effects on the nasal structure. All suspension sutures had the function on elevating the alar cartilage. F2 had no function on restoring the collapse of the nasal tip. The suture which fastened both medial crura together leaded to the lowest stress on the skin envelope. Conclusions Each suspension suture had its characteristics respectively. The simulation suggested that F1, the suture which fastened both medial crura, could be the most potential maneuver for cleft lip rhinoplasty because it can symmetrically restore the shape of the nose without incurring a significant increase in stress.

Computational technology for nasal cartilage-related clinical research and application

“…Ansys Workbench contains a variety of analysis modules that are very convenient to use. [4][5][6][7] COMSOL (COMSOL, USA), FEBio and SolidWorks (CASCIM, USA) have also been used for nasal cartilagerelated finite element analysis. 41,42,45,[53][54][55][56] Finite element meshing is the most critical step for the finite element method.…”

“…4 Next, we applied the finite element method to evaluate the effect of different alar cartilage suspension manoeuvres on a unilateral complete cleft lip nose model reconstructed from micro-MRI data and demonstrated the characteristics of different manoeuvres. 7 Then, we explored the biomechanical forces that should be included during cleft lip rhinoplasty. 5 We also used a secondary unilateral cleft lip nasal deformity model to simulate two suturing manoeuvres during unilateral cleft lip rhinoplasty, including the passive intercrural suture and a suture suspending the alar cartilage from the upper lateral cartilage.…”

“…3a–d ). 5 , 7 More studies are required on applying different MRI imaging sequences to demonstrate the nasal cartilage and comparing these different methods. This would allow for better demonstrations of patient-specific nasal cartilage morphology.…”

“… 3 The research on nasal cartilage-related surgery is conducted primarily to investigate the principles of surgical design and the changes in related physical factors (such as stress conditions, deformation or internal stress in the tissue) caused by the operation. 4 – 7 It differs from basic research on nasal cartilage-related tissue engineering and should be verified by clinical operation and post-operative effect evaluation. Computational technology has become an important tool for nasal cartilage-related surgery and clinical application due to its high efficiency, low costs and ability to analyse and simulate organs and tissues independently.…”

“…Nasal cartilage and facial muscles obtained from MRI scans. a-c Micro-MRI scan of the nasolabial region of an induced infant with unilateral complete cleft lip 5,7. The red arrow indicates the position of the cartilage.…”