Patient Specific Polyetheretherketone (PEEK) Miniplates Versus Titanium Genioplasty Plates in The Fixation of Computer-Guided Advancement Genioplasty
Phase: NA
Conditions: Mandible; Deformity
Sponsor: Faculty of Dental Medicine for Girls

Evaluation of Polyetheretherketone (PEEK) Versus Titanium 
Patient Specific Plates for Fixation in Computer-Guided 
Advancement Genioplasty 
Introduction 
The chin has a major role in the profile and the whole esthetics of the face, 
affecting the individual's psychology and social acceptance (1). The need for 
surgical intervention to alter the size and shape of the bony chin associated with 
changes of the surrounding soft tissues, which is known as "Genioplasty" was 
developed since the isolated chin deformities represent about 15% of all 
dentofacial deformities. Genioplasty was first described by Hofer who performed 
osteotomy anteriorly at the lower border of the mandible via a submental incision, 
followed by Trauner and Obwegeser via labial sulcular incision (1,2).  
Advancement genioplasty is the corrective procedure of the anteroposterior 
chin deficiency. Traditionally, the planning of genioplasty was done using 
analysis of clinical photos and lateral cephalograms, relying on the personal 
experiences and visual assessments of the surgeon to control the three-
dimensional (3D) movements of the distal bone segment during the surgery 
resulting in variable outcomes that could impair the surgical results (3,4).  
Recently, the introduction of virtual surgical planning (VSP) along with 
3D radiographic technology in orthognathic surgery allowed the surgeon to 
produce surgical guides based on preoperative VSP to simulate this plan precisely 
into the operating room. These guides transfer the planned osteotomy site and 
direction during surgery and accurately move the bony segments into the desired 
positions as planned. VSP has additional benefits including optimal planning 
accuracy and reliability, reduced possibilities of vital structure injury, less 
surgical time, achievement of the predictable stable functional and aesthetic with 
better clinical outcome (5,6). 

Regarding the fixation, rigid bone fixation with plate and screws are more 
commonly used because of their reliability, rapid and easy application (7). Fixation 
of the repositioned distal bone segment using titanium plates is commonly used 
because titanium is considered as the gold standard material of plates. However, 
recently polyetheretherketone (PEEK) is considered as an acceptable material for 
reconstruction because of its mechanical properties and it could be used as an 
alternative to titanium due to its biocompatibility, inertness, non-toxicity, high 
fatigue resistance, and ability to initiate osseointegration (8,9). 
Nowadays, PEEK is popular and commonly used in cranioplasty and spine 
surgeries because of its high reliable biocompatibility, excellent corrosion 
resistance, lack of allergic reactions, the possibility of sterilization without loss 
of mechanical properties, permeability to X-ray beam allowing CT examination, 
and the absence of artifacts during MRI. Most importantly its energy-absorbing 
properties and modulus of elasticity which closely resemble the bone more than 
titanium. Therefore, PEEK represents an ideal alloplastic material and has been 
successfully used (9).   
However, a finite element analysis study of PEEK supported the possibility 
of its use as a material for reconstruction plate (10). This study compared titanium 
and PEEK by forming the same standard design of reconstruction plate,  proving 
the validity of using PEEK as a material for reconstruction plate used in fracture 
of the angle of the mandible and the results showed that the mechanical properties 
of the PEEK are more close to the bone and in consequence increasing the static 
safety factor of the plate and improving the fatigue strength criteria. Thus, 
supporting the rationality of using PEEK as a material of reconstruction plate (10).  
To our knowledge, this is the first clinical report of using patient specific 
PEEK plates in the fixation of computer-guided advancement genioplasty and 

evaluate it clinically and radiographically in comparison to patient specific 
titanium plates.    
Aim of the Study 
The aim of this comparative analysis study was to compare 
polyetheretherketone (PEEK) and titanium patient specific plates for fixation in 
computer-guided advancement genioplasty clinically and radiographically.  
Patients and Method 
Subjects 
This study was designed and performed in the departments of Oral and 
Maxillofacial Surgery in Faculty of Dental Medicine for Girls, Al-Azhar 
University and Ahmed Maher Teaching Hospital. After having ethical approval 
from the Research Ethics Committee with code ORSUR-108-2-L, the selection 
of the patients was based on these inclusion criteria (1) Patients who are indicated 
to advancement genioplasty. (2) Patients with completed growth. (3) Physically 
and psychologically able to tolerate surgical procedures. While the exclusion 
criteria were (1) Presence of any medical conditions that contraindicate the 
surgical procedure. (2) Any medical condition that compromises the healing and 
surgical outcome.   
Grouping of Patients 
This study included fourteen patients indicated for advancement 
genioplasty. They were randomly assigned into two groups.  
- Group A included seven patients who were treated by computer guided 
advancement genioplasty using patient specific titanium plates considered 
as a control group. 

- Group B involved seven patients who were treated by computer guided 
advancement genioplasty using patient specific PEEK plates considered as 
a study group. 
The full treatment plan, surgical procedure and possible complications 
were explained and discussed with the patients, and an informed consent form 
was signed as well. All surgeries were performed under general anesthesia 
through nasotracheal intubation. Local anesthesia solution containing 1% 
lidocaine and 1:100,000 epinephrine is infiltrated along the proposed incision line 
and dissection area.   
The incision was performed in the labial mucosa (anterior region of 
mandible), at least 10 to 15mm of mucosa attached to the gingiva. The incision 
was designed to be more superior in the region of canine. Care must be taken not 
to extend the incision too far posteriorly to avoid the mental nerve where it exits 
from the mental foramen, and to identify the branches of the mental nerve which 
are often visible. Then the incision is then completed down to the bone.  
Clinical Procedures 
After documenting past medical and dental history, patients were examined 
clinically and radiographically with Computed Tomography (CT) scan to confirm 
the need for advancement genioplasty. Then the virtual surgical planning (VSP) 
started by transferring the resulting Digital Imaging and Communications in 
Medicine (DICOM) data of CT to ProPlan CMF software (Materialise NV, 
Leuven, Belgium) to perform the osteotomy and the repositioning of the genial 
bone segment  
Then exported the VSP data in the form of Stereolithography into 3-matic 
software (Materialise NV, Leuven, Belgium) to design the surgical cutting and 
repositioning surgical guide and the plate as well in the form of STL files. Then 

the resulting STL data was transmitted to a 3D printing machine to fabricate the 
surgical guide and to a milling machine for the plate production of both groups 
(1,3,11). All patients underwent standard advancement genioplasty (12,13,14) and were 
fixed with either titanium or PEEK patient specific plates. 
Postoperative Evaluation 
1- 
Clinical evaluation 
- Extraoral: Signs of hematoma, infection or inflammation of the skin also 
any neurological affection of mental nerve.  
- Intraoral: Signs of infection or any soft tissue dehiscence or plate exposure. 
2- 
Radiographic evaluation 
- Discrepancy evaluation (Linear measurements) between immediate 
(Within the first postoperative week) and six months postoperative CT by 
comparing the position of hard tissue menton (Me) and hard tissue 
pogonion (Pg) on CT to assess the vertical and horizontal changes 
respectively. 
- Superimposition of the immediate and six months postoperative using 3-
matic software (Materialise) software to measure the linear discrepancy 
and to create a color map (15).  
3- 
Cost evaluation 
- A comparison between the costs of the cutting and repositioning guides in 
addition to the patient specific plates were calculated for each patient in 
both groups in Egyptian pounds. 
4- 
Patient satisfaction evaluation 
- Patient satisfaction with the aesthetic results was evaluated using a 5-point 
Likert scale postoperatively (1 is very dissatisfied, 2 dissatisfied, 3 neither 
dissatisfied nor satisfied, 4 satisfied, 5 is very satisfied). 
-  

Statistical Analysis 
The results were represented from normality tests (Kolmogorov-Smirnov 
and Shapiro-Wilk) conducted on multiple groups (Vertical movement, Vertical 
discrepancy, Horizontal movement, Horizontal discrepancy) and materials (Ti 
and PEEK) to assess whether the data follows a normal distribution. Based on 
these results, all datasets (Across groups A and B) are normally distributed 
according to both the Kolmogorov-Smirnov and Shapiro-Wilk tests. This 
supports the assumption of normality, which is often a prerequisite for parametric 
statistical tests. 
 
Consent 
I declare and acknowledge that I agree to perform the operation and to 
all modifications that may occur during the operation according to the 
necessity, as well as the anesthesia, whether general or local, or any 
type of anesthesia that serves this purpose. 
I also agree to perform advancement genioplasty and fixation of the 
chin 
bone 
with 
patient 
specific 
plates 
(titanium 
or 
polyetheretherketone). 
This is my consent of this without any responsibility on the part of the 
surgeon and anesthesiologist at the hospital 
Name: 
ID:  
Adress: