Free Gingival Grafts (FGGs) in Mandibular Posterior Sites

Study Overview
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Brief Summary
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In this proposed study a novel technique that utilizes bone screws as an anchorage device will be used to facilitate suturing and ensure graft tissue immobilization on full thickness recipient bed preparation sites. Currently, no information is available on free gingival graft treatment outcomes comparing full thickness recipient bed preparation, i.e., no periosteum remaining under the free gingival graft, with the aid of bone screws versus a conventional partial thickness recipient bed preparation with periosteum remaining under the graft. The purpose of the present study is to investigate the effect of these two different recipient bed preparations on soft tissue dimension change, graft and surgical wound healing, patient comfort, surgical complication frequency and operator satisfaction after free gingival graft to increase the width of keratinized gingival tissue in mandibular posterior sites. The purpose of the present study is to investigate the effect of these two different recipient bed preparations on soft tissue dimension change, graft and surgical wound healing, patient comfort, surgical complication frequency and operator satisfaction after free gingival graft procedure to increase the width of keratinized gingival tissue in mandibular posterior sites. The specific aims of this research study contain two aspects: To compare the wound healing of a free gingival graft using either a partial thickness flap or full-thickness flap preparation with bone screws at the recipient site around mandibular posterior areas. To assess patient comfort and surgeon satisfaction with a free gingival graft procedure using these two different recipient bed preparations.

Detailed Description
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While the presence of a sufficient size of keratinized oral mucosa is favorable, the surgical procedure to increase the size is technically difficult. In the traditional way, preparation of the gum bed for a graft tissue is done with partial-thickness flap elevation, in which part of the mucosa and submucosa, but not the periosteum (dense fibrous membrane covering the surface of bones), are separated from underneath bone. In the traditional method of gum bed preparation, separation of the mucosa and submucosa from underneath periosteum and bone should be done with extremely caution to avoid damaging the periosteum. Therefore, the traditional method of gum bed preparation is not only time consuming but also problematic because of more bleeding when compared to full thickness flap elevation, in which the mucosa and submucosa together with the periosteum are separated from underneath bone. In order to stabilize gum graft on bone surface, a new technique is applied in this study by using two bone screws as anchorage to fastened the graft on the exposed bone through suturing. In the present study, we will compare patient quality of life, operator satisfaction, and differences in surgical wound healing between these two different bed preparations. The results of this study could help establish a more patient- and operator-friendly surgical protocol for the use of gum graft to increase the width of keratinized oral mucosa.

Official Title
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Free Gingival Grafts (FGGs) in Mandibular Posterior Sites: A Randomized Clinical Trials of Wound Healing Following Different Recipient Bed Preparations

Conditions
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Lack of Keratinized Tissue

Intervention / Treatment
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* Procedure: Partial thickness recipient bed
* Procedure: Full thickness recipient bed
* Device: Bone screw (FDA approved bone screw)
* Procedure: Periosteal sutures
* Procedure: Sling sutures
* Procedure: Sling sutures around screws


Participation Criteria
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Eligibility Criteria
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A) Target population: Patients whether edentulous or dentate or treated with root-form dental implants, who need FGG on the buccal aspect of the mandibular posterior area. Inclusion criteria <Demographic> Race: Any Non-smokers: No use of any tobacco or nicotine-replacement products for the least 5 years <Medical history> Physically and mentally healthy with no contraindication for periodontal surgery American Society of Anesthesiologists: ASA-1 or ASA-2 Clinical (Oral) conditions: Periodontally healthy patients with no contraindication for free gingival graft procedure (donor and recipient sites) <Other> Patients who need free gingival graft in the mandibular posterior area. Patients who are able and willing to provide informed consent Patients who are able to receive surgery on Tuesday. Exclusion criteria <Medical history> Smokers or users of nicotine replacement products Patients with any history of soft tissue surgery (grafting) in the area to be treated Patients with contraindication for periodontal soft tissue surgery, including an anatomical location of mental nerve that may restrict preparation of 10x10mm recipient bed Patients with contraindication, e.g., allergy, for any of the medications used in the study (benzocaine, lidocaine, chlorhexidine rinse, ibuprofen) Patients with inadequate donor site anatomy. Patients with uncontrolled diabetes (glycemic level > 110mg/l and HbA1c > 6%) Patients with drug or alcohol abuse Pregnant or lactating women Patients with a history of bisphosphonate therapy, radiotherapy in the head and neck region for malignancies, or chemotherapy for treatment of malignant tumors Other systemic conditions or medications affecting surgical or wound healing process and gingival tissues, such as cancer, HIV, metabolic bone diseases, phenytoin, cyclosporine, dihydropyridines, etc. <Dental> •Poor oral hygiene (PlI>2) 28 Subjects will be exited from the study immediately upon: Change of mind regarding participation Development of acute dental/oral conditions requiring treatment Development of a condition requiring treatment that conflicts with the exclusion criteria listed above Failure to comply with study instructions/requirements/appointments B) Target population: Operators Inclusion criteria •2nd and 3rd year residents at Division of Periodontology, The Ohio State University, in good standing. Exclusion criteria •Residents who don't want to participate in the study.

Ages Eligible for Study
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Minimum Age: 35 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Partial-thickness bed preparation<br>Partial-thickness bed preparation for free gingival graft procedure. | Procedure: Partial thickness recipient bed<br>* Flap will be separated by sharp dissection and elevated toward apical direction, leaving the periosteum covering the bone, and the elevated pedicle flap will be incised and removed.<br>Procedure: Periosteal sutures<br>* Interrupted periosteal sutures placed at the 4 corners of each graft, and mesial and distal surfaces to engage the graft at an equidistance from the graft corners.<br>Procedure: Sling sutures<br>* Crossed sling sutures placed over the graft engaging the fixed crestal/lingual KT coronally and the periosteum apically.<br>|
| Experimental: Full-thickness bed preparation<br>Full-thickness bed preparation with bone screw placement for anchoring the sutures. | Procedure: Full thickness recipient bed<br>* Full-thickness (mucoperiosteal) flap will be raised on the recipient bed to establish a denuded bone area. Two bone screws will be placed at the most apical border of the denuded bone.<br>Device: Bone screw (FDA approved bone screw)<br>* Two bone screws placed at the most apical border of the denuded bone after osteotomy.<br>Procedure: Periosteal sutures<br>* Interrupted periosteal sutures placed at the 4 corners of each graft, and mesial and distal surfaces to engage the graft at an equidistance from the graft corners.<br>Procedure: Sling sutures around screws<br>* Crossed sling sutures placed over the graft engaging the fixed crestal/lingual KT coronally and each is apically looped around the corresponding apically positioned screw.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Graft width, length and area | Graft length and width will be confirmed after harvest and remeasured in situ, using a digital caliper, after completion of the surgical procedure. Subsequently, graft length and width will be measured on clinical images obtained at the post-op visits. A mirror image photo of the grafted site will be taken with a single-lens reflex camera and the dimension will be measured and analyzed with Image J software. Size markers will be used to calibrate image magnification. Graft area will be calculated from the length and width measurements. | During the surgery, at the 1-, 2-, 4-, 8- week visits | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Wound healing index | Clinical photographs of the recipient sites will be taken at baseline, immediately after surgery, and at each follow-up visit, to record the appearance of the graft. A size marker will be used to standardize photos. Small size mirror will be placed with caution to avoid any disturbance of the surgical site, and mirror image photo will be taken. Wound healing index by Pippi et al. , which is the modified Wound Healing Index by Landry et al., is customized and used to evaluate the healing potential of the graft. | At the 3-day, 1-, 2-, 4-, 8- week visits | 
| Graft thickness | Graft thickness will be measured in situ with digital caliper, and at the 8-week follow-up visit using an endodontic reamer, at five (5) predetermined points. A central point will be located at the geometric center of the graft, where the two diagonals of the square intersect. The other four points will each be located on the diagonal, at 3 mm from the corner of the graft. Pre-fabricated acrylic stent with holes for the measurements will be used to standardize measurement location. At 8 weeks, graft thickness measurements will be repeated following topical and local anesthesia using infiltration. | During the surgery, at the 8-week visits | 
| Graft mobility | At the end of the procedure, graft mobility will be assessed indirectly and graded. While exerting tension on the cheek/vestibule, graft will be observed for mobility. Mobility will be graded indirectly, by exerting tension on the cheek/vestibule, and directly, by applying gentle force on the graft using a periodontal probe, in a manner similar to the functional approach used to locate the mucogingival junction. | At the end of surgery, at the 8-week visits | 
| Biochemical wound assessment | Wound fluid will be collected from the transplanted graft site. Paper strips will be left in place for 30 sec and then immediately transferred to a micro-moisture meter to determine the volume of collected fluid. Following volume measurement, paper strips will be immediately placed into a vial, on ice; fluid collection will be repeated after 5 minutes. Then the vial with the 4 paper strips will be transferred to a -80˚C freezer until further analysis. Expression of angiogenesis biomarkers will be quantified with the use of a human angiogenesis custom array kit according to the manufacturer's protocol. | At the 3-day, 1-, 2- week visits | 
| Surgical time | Length of surgery will be measured at the time the operator starts the first incision in the recipient bed and stopped when the last suture placement is placed. Bed preparation and graft placement will be independently timed to compare between procedures and with operator's opinion. | During the surgery | 
| Pain assessment. | A visual analogue scale (VAS) will be used to measure daily pain intensity at each postoperative week. The self-reported degree of pain will be scored, with 0 defined as the absence of pain and 10 as the maximum tolerable level of pain. The intake of NSAIDs will be also recorded. . | At the 3-day, 1-, 2-, 4-, 8- week visits | 
| OHIP-14 | The oral health-related quality of life will be assessed by the Oral Health Impact Profile scale (OHIP-14). Participants will be asked how frequently they had experienced the impact on each category in OHIP-14 with a 5-point scale (from 0 to 4). The total score of OHIP-14 will be calculated by adding the sum of each category from 14 questions (total score ranges from 0 to 56 points). Higher scores imply a poorer oral health quality of life, whereas lower scores indicate a better one. | Right before the surgery and at the 3-day, 1-, 2-, 4-, 8- week visits | 
| Operator-centered outcomes | Immediately after the surgery, operators will receive custom questionnaire to assess the difficulty of the surgery. Each step of the surgery will be categorized and will be marked with 10-point scale (from 0 to 10) based on the surgical difficulty and time management. After completion of the 2-week post-op visit, operators will be asked to assess difficulty of screw removal (test group only). Also, after each enrolled operator has conducted all allocated cases (2 cases of full-thickness flap group and 2 cases of partial-thickness flap group, possibly up to 1 year.), including all 2-week post-op visits, he/she will be asked to report their preference of procedure (control or test) | Immediately after the surgery, 2-week post-op visit and when an operator has conducted all allocated cases |