Effect of Botulinum Toxin-A on Free Gingival Graft
Condition: Gingival Recession, Localized
MeSH terms: Gingival Recession
Study type: Interventional

Summary: 
      The aim of this study was to examine the effects of Botulinum Toxin-A (BTX-A) injection to
      the mental muscle on the free gingival graft (FGG) operation. Forty patients with Miller
      class III gingival recession and keratinized gingival insufficiency in their lower 1st
      incisors were divided into 2 groups as FGG operation (n=20) and 5 unit (U) BTX-A injection
      into the mental muscle immediately after FGG operation (n=20). Periodontal parameters (plaque
      index (PI), gingival index (GI), probing pocket depth (PPD), keratinized gingival amount
      (KGA), attached gingival amount (AGA)) were measured from the lower 1st incisors at the
      beginning and at the 1st, 3rd and 6th months after the operation, clinical attachment level
      (CAL), gingival thickness (GT), gingival recession amount (GRA), gingival recession width
      (GRW) and root closure percentage (RCP (%)) were evaluated. There was no statistically
      significant difference in terms of PI and GI levels (p>0.05). The PPD levels of the study
      group at the postoperative 3rd month was found to be statistically significantly lower than
      the control group (p<0.05). While the change in GT and RCP (%) levels were found to be
      statistically significantly higher than the control group, the change in GRW and CAL levels
      were statistically significantly lower (p<0.05). According to the results of this study, it
      can be stated that BTX-A injection applied to the mental muscle after FGG operation may have
      positive effects in terms of KGA, AGA, GT, RCP (%), GRW and CAL parameters.
    

Detailed description: 
      INTRODUCTION The FGG operation is a versatile surgical procedure that is frequently used in
      the treatment of gingival recessions to increase the width of the attached gingiva, the depth
      of the vestibule and to close the open root surface. While it is a more successful method in
      closing the open root surface in patients with Miller class I and II gingival recessions
      without bone loss, the same success cannot be observed in patients with Miller class III and
      IV gingival recessions with bone loss in the interdental area. The most important factors
      affecting the success of the FGG operation are the ensurement of the nourishment of the graft
      by maintaining the blood supply and the ensurement of graft immobility in the early recovery
      period by blocking the return of the dissected muscle attachments to their original position.
      Insufficient blood supply to the recipient bed where the graft is placed causes necrosis in
      the graft. In this case, there is a risk that the root surface cannot be completely covered.
      In addition, due to the desire of the dissected muscle attachments to return to their
      original position, there is a risk of not being able to achieve the desired amount of
      keratinized band increase.

      Botox (BTX) is a toxin obtained from the Clostridium Botulinum bacteria and is a microbial
      protein that shows its effect by blocking neuromuscular activity. Immunologically, there are
      8 different serotypes of BTX (A, B, C1, C2, D, E, F, G). Serotype A is the most potent
      serotype and the first form used in medicine. BTX-A is an agent used in medicine and
      dentistry for therapeutic purposes as well as cosmetic purposes. In the field of dentistry,
      it is preferred as a treatment method in many pathological conditions such as oromandibular
      dystonia, bruxism, asymmetry due to facial paralysis, temporomandibular joint (TMJ)
      disorders, gummy smile, and orange peel-looking jaw. There are studies showing that BTX
      application causes vasodilation in the blood vessels of the injected area; increasing the
      amount of blood flow and oxygen delivery at the vascular, tissue, cell and molecular levels
      in the region. It has been reported that this effect eliminates the risk of the necrosis of
      the graft whose blood connection was cut due to the increased blood supply in the region and
      also contributes to flap viability.

      The mental muscle is a pair of muscles on the right and left, starting from the jawbone at
      the apical level of the incisors, moving downwards, and ending at the skin. The contraction
      of the mental muscle, which provides the vertical support of the lower lip; raises the lower
      lip and chin, creating a sullen and sad expression on the face. Due to the mental muscle
      ending at the skin, excessive activity of the muscle causes an indented appearance of the
      chin, which is called the orange peel. BTX injection applied to the mental muscle contributes
      to the improvement of the orange peel appearance by reducing the excessive activity of the
      muscle.

      The aim of this retrospective study was to evaluate the effects of BTX-A injection to the
      mental muscle on patients with Miller class III gingival recession in their lower 1st
      incisors who underwent the FGG operation due to insufficient keratinized gingiva, on the
      basis of clinical periodontal parameters. Due to the fact that BTX-A injection applied to the
      mental muscle increases the blood supply of the region and decreases mental muscle activity
      suggests that it will positively affect the clinical periodontal parameters.

      MATERIAL AND METHODS This study, which was approved by the Ethics Committee of Fırat
      University Medical Faculty Clinical Research Ethics Committee with the number 12/27 on
      01.08.2019, was supported by the Fırat University Scientific Research Projects Management
      Unit with the project number DHF.19.10.

      Study Population The study was carried out on 40 lower incisors of 40 patients who applied to
      the Fırat University Faculty of Dentistry Department of Periodontology between the years of
      2019 and 2021, who had Miller class III gingival recession in their lower 1st incisors, and
      were treated with FGG operation due to insufficient amount of keratinized gingiva. The
      patients were divided into 2 groups as randomized controlled.

      Control group (FGG) (n:20): The patients in this group only underwent the FGG operation.

      Study group (FGG+BTX) (n:20): The patients in this group received 5 U BTX-A injection into
      the mental muscle immediately after the FGG operation.

      Study Design In order to maintain the standardization of the study; it was made sure that the
      FGG operation, which is one of the treatment methods for gingival recession, and the BTX-A
      injection applied to the mental muscle were performed by the same physician (KS). In order to
      eliminate biased behavior, an experienced physician (TTY) who did not know which group the
      patients belonged to performed all clinical periodontal measurements. The study was
      terminated after the retrospective evaluation of the clinical periodontal parameters recorded
      in the patient follow-up forms at the baseline, 1st, 3rd and 6th month of the study period.

      Clinical Procedure Non-Surgical Periodontal Treatment In this retrospective evaluation study;
      patients included were applied phase I periodontal treatment (detertrage and subgingival
      curettage), which is routinely applied in the clinic, before each surgical procedure and were
      also given oral hygiene training. The study protocol was explained to patients undergoing the
      FGG operation and FGG+BTX application and written informed consent was obtained from each
      individual prior to clinical periodontal examination.

      Clinical Measurements PI, GI, PPD, KGA, AGA, CAL, GRA, GRW levels were measured at the
      baseline and at the postoperative 1st, 3rd and 6th month; GT parameters were measured at the
      baseline and the postoperative 6th month with a William's type periodontal probe (Nordent
      Manufacturing Inc, Elk Grove Village, IL, USA) with a 0.5 mm diameter. The RCP (%) was
      calculated using the formula below at the postoperative 6th month.

      Baseline GRA - Postoperative 6th month GRA RCP (%) = --------------------- X 100 Baseline GRA

      In order to provide standardization, clinical measurements of the study area were obtained
      from the reference point chosen as the midbuccal surface. In cases where the FGG operation
      was performed on both lower first incisors, one of the teeth were chosen at the baseline and
      measurements were made from the same tooth throughout the study period.

      Surgical Procedure The surgical procedure was started by applying infiltrative local
      anesthesia (2% lidocaine, 1/100.000 epinephrine) to the operation area. The initial
      horizontal incision was made on the Mucogingival line with a number 15 scalpel. This incision
      was deepened in the apical direction with sharp dissections. The recipient bed size was
      prepared in accordance with the graft size which was determined as 7 mm in the apico-coronal
      direction and with a distance of 3 mm from the graft edges in all directions. Deepitelization
      of the gingiva remaining in the coronal part and root surface straightening of the lower
      incisors were performed. The recipient bed preparation was completed by washing the operation
      area with 0.9% sterile saline. The graft area was determined as the palatal region, which
      does not contain rugae, between the mesial of the first molar and the distal of the canine in
      the upper jaw. After local infiltrative anesthesia (2% lidocaine, 1/100.000 epinephrine)
      application to the palate region, the graft was obtained with a number 15 scalpel. Bleeding
      in the palate area was controlled by applying pressure with moist gauze for 5 minutes. The
      excess fat tissue on the inner surface of the graft was cleaned on a moist sponge with a
      sharp scalpel or curved-tipped tissue scissors and the fixation phase was started at the
      recipient site. The graft was fixed to the recipient bed with the minimum number of
      monofilament non-resorbable 5-0 polypropylene (Katsan, İzmir, Turkey) sutures at the most
      coronal region of the crestal bone. Vials of 100 U Allergan Botox® (Allergan, Inc., Irvine,
      California) were diluted with 2 ml of physiological saline and made ready for use. The
      midline was determined at the mentum region. 5 U of BTX-A was injected into the mental muscle
      approximately 1 cm away from the chin tip and the midline. Amoxicillin + clavulanic acid 1000
      mg (2 times a day), dexketoprofen 25 mg (2 times a day) and 0.12% chlorhexidine gluconate
      mouthwash (3 times a day) were prescribed to each patient to control the risk of
      post-operative pain and infection. It was recommended that the patients brush the areas other
      than the operation site 2 times a day, 1 day after the operation. It was recommended to
      gently clean the graft surface with the help of a cotton swab soaked in mouthwash. The
      sutures were removed on the post-operative 21st day. Photographs of the recipient area were
      recorded at the baseline and the postoperative 1st, 3rd, and 6th month of each patient
      included in the study.

      Statistical Reviews While evaluating the recorded findings in this retrospective study, the
      IBM SPSS Statistics 22 program was used for statistical analysis. The suitability of the
      parameters to the normal distribution was evaluated with Kolmogorov-Smirnov and Shapiro Wilks
      tests and was determined that the parameters did not show normal distribution. The Mann
      Whitney U test was used for the comparison of the parameters between the two groups, and the
      Friedman test (post hoc Wilcoxon sign test) was used for comparisons within each group.
      Spearman's rho correlation analysis was used to evaluate the correlations between the
      parameters. Significance was evaluated at the p<0.05 level.
    

Intervention name(s): BTX-A; free gingival graft
Intervention type(s): Other; Procedure
Intervention description(s): Vials of 100 U Allergan Botox® (Allergan, Inc., Irvine, California) were diluted with 2 ml of physiological saline and made ready for use. The midline was determined at the mentum region. 5 U of BTX-A was injected into the mental muscle approximately 1 cm away from the chin tip and the midline; The mandibular first incisor was treated with FGG operation due to Miller class III gingival recession and insufficient amount of keratinized gingiva.
Other intervention name(s): 100 U Allergan Botox®; Allergan, Inc., Irvine, California; Botox
Intervention MeSH terms: Botulinum Toxins, Type A; abobotulinumtoxinA
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: The study was carried out on 40 lower incisors of 40 patients who applied to the Fırat University Faculty of Dentistry Department of Periodontology between the years of 2019 and 2021, who had Miller class III gingival recession in their lower 1st incisors, and were treated with FGG operation due to insufficient amount of keratinized gingiva. The patients were divided into 2 groups as randomized controlled.
Control group (FGG) (n:20): The patients in this group only underwent the FGG operation.
Study group (FGG+BTX) (n:20): The patients in this group received 5 U BTX-A injection into the mental muscle immediately after the FGG operation.
Masking: None (Open Label)
Primary purpose: Other
Keywords: Gingival recession; free gingival graft; mental muscle; Botulinum Toxin-A; keratinized gingiva