Comparative evaluation of modified frenectomy with papilla preservation flap versus conventional technique in upper labial frenectomy: a randomized controlled trial

Abstract

Introduction:

Cosmetic concerns among patients have led to an increased demand for dental treatments aimed at achieving a perfect smile. One of the main cosmetic issues in adults is the gap between the upper incisors, known as diastema, and the upper lip frenulum is often a contributing factor to this condition. Therefore, it is imaportant to focus on this aspect.

Objective:

To explore a new technique for cutting the upper lip frenulum in patients with a gap between the central incisors while avoiding the negative effects of the traditional technique.

Materials and methods:

This randomized controlled clinical trial included 20 patients diagnosed with abnormal upper lip frenal attachment and diastema between the central incisors. The study compared the modified frenectomy technique with a papilla preservation flap against the traditional “Archer” technique. Each technique was performed on 10 patients, and outcomes such as scar formation, gingival inflammation, and post-surgical pain were evaluated.

Results:

The “modified frenectomy with papilla preservation flap” technique prevented scar formation in the papilla area between the upper incisors in nine cases, while scar formation occurred in seven cases using the traditional technique. There were no statistically significant differences in gingival inflammation post-surgery. Pain levels were lower with the modified technique: on the first day, the average pain score was 1.5 for the modified technique and 2.8 for the traditional technique. By the third day, the average pain was 4.3 for the modified technique and 6.9 for the traditional technique, with pain decreasing by the seventh day to an average of 0.7 for the modified technique and 1.6 for the traditional technique.

Conclusion:

The modified frenectomy with a papilla protection flap effectively reduces scarring, enhances healing, and minimizes postoperative pain, offering a more comfortable and aesthetically better result than conventional methods.

Introduction

Increasing cosmetic concerns have led more patients to seek dental treatments in their pursuit of the perfect smile. While a restricted labial frenulum, or lip tie, can affect speech development, particularly in older children due to limited upper lip movement that may hinder the ability to make certain sounds and words, one of the most common aesthetic issues in adults remains the gap between the upper central incisors, known as maxillary midline diastema (MMD) which directly impacts dental appearance.^[1] According to Andrews, gaps between teeth should naturally close after the eruption of permanent teeth, following the six keys to ideal occlusion. However, in some cases, these gaps persist and are classified as diastema.^[2]

HIGHLIGHTS

• The modified frenectomy with papilla preservation flap significantly reduces scar formation compared to the traditional technique.

• Patients experienced lower postoperative pain with the modified technique, especially on the first and third days.

• No significant difference in gingival inflammation between the techniques, though the modified approach showed better overall healing outcomes.

Diastema is a common physiological appearance in temporary and mixed dentition (normal between ages 7 and 12), with its size and prevalence decreasing after the eruption of permanent teeth.^[3]

There are various causes of diastema, which Attia classified into four groups:

1. Dental defects, such as small teeth or missing teeth, especially missing upper lateral incisors, or the presence of extra teeth, particularly mesiodens.

2. Muscle influences, such as an enlarged tongue.

3. Neuromuscular defects, such as improper tongue positioning during rest or function, including swallowing and speech.

4. Periodontal defects, such as improper attachment of the frenulum, which is one of the most common causes of diastema formation and may lead to relapse after orthodontic treatment.^[4-9]

Several studies have reported spontaneous closure of diastema between the upper incisors after frenectomy (removal of the upper lip frenulum), with or without orthodontic treatment. In Suter’s study, several diastemas closed spontaneously after frenectomy. The results were highly satisfactory in patients who underwent frenectomy in conjunction with appropriate orthodontic treatment, but the timing of the procedure remains a subject of debate.^[10]

An oversized frenulum can cause other issues, such as difficulty brushing and cavities in the upper central incisors, especially in children. It may also lead to periodontal problems, particularly when frenulum movement is associated with soft tissue movement between the incisors, potentially causing future gum recession.^[11,12]

The treatment of the upper lip frenulum involves two methods:

1. Complete removal of the frenulum (frenectomy).

2. Repositioning of the frenulum (frenotomy).

Complete frenulum removal is defined as the removal of frenulum tissue along with its bony attachments beneath it, while repositioning refers to making an incision within the frenulum and relocating its attachments apically.

The traditional technique for frenulum treatment involves excision using a conventional scalpel, although there are other techniques, such as using an electric scalpel or laser^[13].

The classical frenectomy technique was introduced by Archer (1961) and Kruger (1964). This approach was recommended in the midline diastema cases with an aberrant frenum to ensure the removal of the muscle fibres which were supposedly connecting the orbicularis oris with the palatine papilla. This technique is considered an excision type frenectomy which includes the interdental tissues and the palatine papilla along with the frenulum. It involves excising the frenum completely with a hemostat.^[14]

Miller’s technique, introduced by PD Miller in 1985, was designed for post-orthodontic diastema cases. It is ideally performed after orthodontic movement is complete, about 6 weeks before appliance removal, allowing for healing, tissue maturation, and use of orthodontic appliances to retain a periodontal dressing. This technique involved excising the frenulum, exposing the midline labial alveolar bone, and then suturing a laterally positioned split-thickness pedicle graft across the midline after a horizontal incision separated the frenulum from the interdental papilla.^[15]

Z-plasty is indicated for frenum hypertrophy with low insertion and an associated inter-incisor diastema that persists after the lateral incisors erupt. It involves incisions at both ends of the frenum, creating two triangular flaps that are transposed across the midline and sutured in a Z-plasty.^[16]

A V-Y plasty is used to lengthen localized areas, such as broad frena in the premolar-molar region. The procedure involves grasping the frenum with a hemostat, making a V-shaped incision, and then suturing it in a Y shape.^[16]

As previously presented, many techniques have been developed for treating the upper lip frenulum, and this study aims to evaluate a new frenectomy technique for improving midline diastema that reduces pain and gingival inflammation while preventing scar formation in the papilla area.

Materials and methods

To achieve the research objective, the investigators developed and conducted a randomized clinical trial, adhering to the Declaration of Helsinki and the Consolidated Standards of Reporting Trials (CONSORT) guidelines for clinical trial reporting.^[14]

This study is registered in the Research Registry under the identification number: researchregistry (number), with the following reference link: https://www.researchregistry.com/browse-the-registry#home/.

Participants

The study population was composed of all patients presenting for evaluation and management of abnormal upper labial frenulum at University’s Hospital between December 2021 and May 2023.

To be included in the study sample, patients needed to meet the following criteria: a high labial frenulum with a gap between the upper incisors greater than 1 mm, being medically healthy with no conditions that could interfere with the surgical procedure or healing process and being over 13 years old with a permanent dental occlusion. Conversely, patients were excluded if they had complete edentulism (total tooth loss), had previously undergone frenectomy surgery, were medically unfit, had diabetes due to its impact on healing, or were under 13 years old, particularly before the eruption of their permanent canines.

Variables

The primary predictor variable was mainly the treatment protocol in the study.

Primary outcome variables include:

1. Scar formation which is assessed using the Von Arx (2008) scar index^[15]:

• No scar present.

• Scar present but measuring less than 1 mm.

• Scar present and measuring more than 1 mm.

The scar size is measured using a Williams probe at its largest diameter.

Inflammatory Condition of Gingival Tissues:

2. The inflammatory state of the gingival tissues which is evaluated by observing the tissue color three months after the procedure, based on the following criteria from Kiranpreet (2016)^[16]:

0. Pink: Normal.

1. Slightly red: Mild gingivitis.

2. Deep red: Acute inflammation of gingival tissues.

3. Bluish-red: Chronic inflammation of gingival tissues.

4. White: Presence of scarring in the gingival tissues or in heavy smokers.

3. Postoperative Pain

Pain after the surgery is measured and rated on a scale of 1 to 10, according to the patient’s self-assessment using the Visual Analog Scale (VAS). Pain is recorded on the first, third, and seventh days following the surgery.

Statistical analysis

All statistical analyses were performed using IBM SPSS version 27.0 (2020) for Windows. The Chi-square test and Phi test were employed to examine the relationship between the surgical technique and the predictor variables.

Study sample

A total of 20 patients were treated at the University Hospital between December 2021 and May 2023. Participants were divided into two groups by randomly drawing a card from a set containing numbers 1 and 2. A card with the number 1 indicated the traditional technique, while a card with the number 2 indicated the modified technique. Both the participants and the researcher were unaware of which surgical technique would be selected.

Surgical procedure

Patients began by rinsing their mouths with a 0.12% chlorhexidine digluconate mouthwash (Bio Fresh-K®). Their lips and surrounding skin were then treated with povidone-iodine®. For anesthesia, a local infiltrative approach was used, administering lidocaine 2% with 1:1 000 000 epinephrine (Adrecaine®) to both the vestibular and palatal regions.

For the control group, the classical technique was performed as follows:

The frenum was clamped with a haemostat, positioned deep within the vestibule, and precise incisions were made along its upper and lower surfaces until the haemostat was fully released. The triangular section of the frenum, held by the haemostat, was carefully excised. A blunt dissection was performed down to the bone to release the fibrous attachment. The edges of the diamond-shaped wound were sutured using 4-0 black silk (SURGIReal®) in interrupted stitches, and the area was protected with a periodontal pack. One week later, both the pack and sutures were removed, marking the completion of the healing process. Fig. 1.

Figure 1.

A clinical case of classical frenectomy. (a) Preoperative abnormal frenal attachment. (b) Frenum held with hemostat. (c) Frenum excised. (d) Surgical field after frenum excision. (e) Sutures placed. (f) Clinical result 3 months postoperatively.

For the study group, the modified frenectomy technique with a papilla preservation flap was performed as follows:

Stage 1

In the first stage of the surgery, a modified frenectomy technique was combined with a papilla preservation flap.

• Step 1: A semilunar incision was made along the midpalatal suture, positioned just behind the central incisors. This incision was extended into a sulcular incision along the mesial side of the central incisors and carried to their distobuccal line angles, with the goal of preserving the papilla. Fig. 2

• Step 2: A 1.0 to 1.5 mm full-thickness flap was elevated, moving palatally through the diastema and then buccally, to fully release the frenal attachments from the buccal bone.

• Step 3: Since the frenal attachments extended in a buccopalatal direction and had infiltrated the bone defect, these attachments were carefully removed using a Sugarman bone file, ensuring the defect was thoroughly cleaned.

• Step 4: The flap was repositioned in its original place on the palate and sutured with 4-0 black silk (SURGIReal®) sutures.

Figure 2.

Surgical incision planning.

Stage 2

The second stage of the surgery involved performing a frenotomy while carefully avoiding the papilla.

• Step 1: The frenum was dissected using a classic technique, ensuring a 2-mm distance from the papilla.

• Step 2: After the frenotomy, the wound margins were undermined to allow for optimal closure.

• Step 3: Suturing was completed using 4-0 black silk (SURGIReal®) sutures (Fig. 3).

Figure 3.

A clinical case of the modified frenectomy technique. (a) Preoperative Abnormal frenal attachment. (b) Transposition of the interdental papilla from the palatal side to the buccal side. (c) The frenum is dissected at a 2-mm distance from the papilla. (d) The labial surface is sutured. (e) Clinical result three months postoperatively.

Follow-up

Follow-up continued for 6 months to demonstrate the effect of surgical treatment on the upper labial frenum (Fig. 4).

Figure 4.

A clinical case of the modified frenectomy technique. (a) Preoperative abnormal frenal attachment. (b) Transposition of the interdental papilla from the palatal side to the buccal side. (c) The frenum is dissected at a 2-mm distance from the papilla. (d) The labial surface is sutured. (e) Clinical result 6 months postoperatively.

Results

The study sample consisted of 20 patients, with 10 undergoing the traditional technique and the other 10 receiving the modified technique. Figure 5 shows the distribution of the sample according to the type of frenulum and the cutting technique used. The mucogingival frenulum type was present in five patients for each technique. The papillary frenulum type was observed in five patients who underwent the traditional technique and in three patients who had the modified technique. The penetrating frenulum was found in two patients who underwent the modified technique, while no patients had mucosal frenulum.

Figure 5.

Graphical representation of the study sample distribution according to the cutting technique and type of frenulum.

Scar formation

Figure 6 shows the distribution of the study sample according to the cutting technique and the scar index. Nine patients who underwent the modified technique showed no scar formation after surgery, compared to three patients with the traditional technique. Patients with a scar index of <1 mm included one patient in the study group and seven patients in the control group.

Figure 6.

Graphical representation of the study sample distribution according to the cutting technique and scar index.

Table 1 shows the results of applying the Chi-square test and Phi test, with both tests yielding a significance level of 0.006. This indicates a significant correlation between the type of technique and the scar index at a 5% significance level, with the scar index being notably better in the modified technique at this significance level.

Table 1.

Results of the Chi-square test and Phi test for the correlation between the technique type and the scar index

Test Type	Test Value	P-value	Significance
Chi-square Test	7.5	0.006	Significant
Phi Test	0.612	0.006	Significant

Gingival inflammation

Figure 7 shows the distribution of the study sample according to the cutting technique and the degree of inflammation. The number of cases with no inflammation was lower with the modified technique, with 6 out of 10 patients showing no inflammation, compared to only two cases in the traditional technique. Mild inflammation was observed in seven cases in the traditional technique.

Figure 7.

Graphical representation of the study sample distribution according to the cutting technique and gingival inflammation.

Table 2 shows that the significance level of the Chi-square test and the concordance coefficient was 0.148, which is greater than 0.05. Therefore, there is no significant correlation or relationship between the type of technique and the severity of inflammation at a 5% significance level.

Table 2.

Results of the Chi-square test and Phi test for the correlation between the technique type and gingival recession

Test Type	Test Value	P-value	Significance
Chi-square Test	3.818	0.148	Not significant
Contingency Coefficient Test	4.00	0.148	Not significant

Pain

Figure 8 shows the distribution of the study sample according to the cutting technique and pain.

Figure 8.

Graphical representation of the distribution of pain index frequencies in the study sample according to the cutting technique and day.

A T-test for independent samples was applied to compare the average pain levels between the two techniques over the treatment days. The results showed significant differences on all days between the traditional and modified techniques, with a statistically significant reduction in pain for the modified technique at both the 5% and 1% significance levels. Table 3.

Table 3.

Results of the T-test for independent samples to compare the mean pain index between the study group and the control group

Comparison Days	Mean Differences	Standard Deviation	T-Test Value	Test Significance	Significance
Day 1	−1.300	1.059	−3.881	0.004**	Significant
Day 3	−2.400	1.838	−4.129	0.003**	Significant
Day 7	−0.900	0.8756	−3.250	0.010*	Significant

Discussion

Despite all the modifications proposed for the technique of cutting the upper lip frenulum, the traditional Archer technique remains the most widely used and applied. However, this technique results in a long incision and may lead to scar formation, which can cause some periodontal issues and an unesthetic appearance. This has driven the search for modifications to the technique.

Among the various approaches to frenectomy, the use of an electrocautery or laser was found to be most advantageous. These methods save time and eliminate the need for suturing, in addition to providing a hemostatic effect that reduces bleeding after the incision.

The traditional technique and the V-shaped incision technique have failed to achieve the desired aesthetic results, particularly in cases of broad or thick frenula. This is due to the inability to close the central area effectively and achieve healing in the exposed area, causing discomfort for patients with a high smile line and exposure of the lower gingival tissues.

The Z-plasty technique has been proposed as an alternative to the traditional method for cases of broad and thick frenula or those with low attachment associated with a gap between the upper incisors and shallow vestibule. It offers two benefits:

1. Removal of fibrous bands.

2. Increased depth of the vestibule.

However, this technique is criticized for its difficulty in application and the potential for partial tear of the flaps during creation and elevation.

The Millar technique – using unilateral displaced flaps – and the bilateral displaced flaps technique proposed by researcher Mohannad Saik have shown good aesthetic results. These flap techniques provide a continuous bundle of collagen fibers across the midline during the healing period, offering a tightening effect on the frenulum, reducing the likelihood of relapse, and minimizing post-incision scar formation due to the lack of central areas for secondary healing. However, these flap designs may be relatively challenging for novice practitioners, and the unilateral Millar technique might cause lateral displacement of the frenulum from the midline post-surgery.^[17-20]

In our study the modified frenectomy technique with a papilla preservation flap was applied to 10 patients, while the traditional technique was used on 10 other patients. We found that the rate of gingival inflammation was not statistically significant at the 5% level but was significant at the 10% level. The modified technique had a significant impact on scar formation between the incisors, whereas no significant differences were observed between the techniques regarding gingival recession.

Regarding postoperative pain, the modified technique demonstrated superior results compared to the traditional technique on the first and seventh days, as well as in the average pain level during the first week. This improvement can be attributed to the smaller surgical incision made with the modified technique and the fact that no tissue was excised.

Discussion of scar index

Our study reached results similar to those of researcher Kampalyal in 2013, where the traditional technique resulted in the formation of defective scar tissue along the midline, with varying sizes, most of which in our study were <1 mm. The modified technique used in our study did not lead to scar formation, unlike the study by Kampalyal which applied both unilateral and bilateral displaced flap techniques. Preventing scar tissue formation was due to not leaving the surgical field for secondary healing. Thus, preventing the formation of defective collagen fibers and promoting the creation of continuous epithelial tissue.^[15]

Our study’s findings are consistent with those of researcher Krishna Chaubey in 2011, who used the Miller technique along with laterally displaced anchored grafts. The use of the graft helped avoid leaving the papilla area for secondary healing and contributed to primary closure, preventing the formation of defective scar tissue in the area. This aligns with our study, where no scar tissue formation occurred due to the avoidance of using a scalpel to create a wound in this region.^[21]

In researcher Devishree’s 2012 study on various frenectomy techniques, the use of unilateral displaced flaps did not result in scar tissue formation, in contrast to the traditional technique. This corresponds with our study and its results, which also prevented scar tissue formation in the area because neither technique left the area for secondary healing.^[22]

Our study outperformed researcher Jeevanand Deshmukh’s 2015 study, which applied the semi-lunar flap repositioned apically in only one case and observed the formation of a small white scar.^[23]

Discussion of gingival inflammation index

Our study’s results were similar to those of researcher Kampalyal in 2013, who used the unilateral displaced flap technique. Kampalyal’s study showed complete healing and absence of discoloration in the gingival tissue after surgery. This similarity is attributed to the fact that the displaced flap technique facilitates primary closure, whereas the modified technique with a papilla protection flap does not cause any damage to this area, as the surgical incision is made at a level higher than the papilla between the incisors.^[15]

Our findings are also comparable to those of researcher Muhannad Seek in 2018, who used the bilateral displaced flap technique. Although gingival inflammation was observed, the statistical differences were not significant because the technique does not leave any empty space at the midline for secondary healing in the papilla area between the incisors. In contrast, our technique does not cause any damage to this area, with the incision being palatal and coronal.^[24]

Researcher Devishree in 2012 found that the traditional technique caused issues with surrounding periodontal tissues as well as an unesthetic appearance. This is because the traditional technique involves making a long vestibular incision, whereas our technique reduces these issues by making the incision palatally to remove frenal attachments and then repositioning the tissue to its natural position. Thus, avoiding any changes to the papilla and free gingiva.^[25]

In a study by Dr. Nirwal Anubah and colleagues in 2010, they used the Millar technique with an anchored flap and observed that the color in the surgical area was consistent with the surrounding gingival tissue. This is similar to the results of our current study. Dr. Nirwal attributed this to not leaving the papilla between the incisors for secondary healing, despite the involvement of fibers in the area. In contrast, our study focused on the involvement of these fibers palatally.^[26]

Discussion of pain index

Our study’s results were consistent with those of researcher Shahabe Saquib Abullais in 2015, who compared pain outcomes between the traditional technique and the parallel flap technique. In that study, the average pain score on the first day was 2.9 for the traditional technique and 1.7 for the parallel flap technique. In our study, the pain index was 1.5 for the traditional technique and 2.8 for the modified technique, aligning with the findings of Abullais and showing that our technique outperformed the traditional technique on the first day. On the seventh day, the average pain score for the traditional technique in Abullais’ study was 2, while it was 1 for the parallel flap technique. In our study, the average pain was 1.6 for the traditional technique and 0.7 for the modified technique, indicating that both techniques performed better than the traditional technique in reducing pain. Our technique also showed a relative advantage over the parallel flap technique, likely due to avoiding any exposed areas in the oral cavity.^[27]

In researcher Ana Claudia’s 2019 study, it was found that pain levels on the first and seventh days were significantly lower when using a laser compared to a traditional scalpel. This contrasts with our study, which used a traditional scalpel, as the laser’s ability to reduce bleeding and coagulate nerve endings and lymphatic vessels helps lessen the inflammatory response post-surgery.^[25]

Researcher Cancat Kara’s 2008^[28] study observed a significant difference in postoperative pain levels on the first and seventh days. 37% of patients who underwent traditional treatment required analgesics, while only 5% of patients treated with lasers needed them. This surpasses our study, where most patients required analgesics (paracetamol) in the first three days post-surgery. This difference is attributed to the traditional scalpel’s tendency to cause an inflammatory response with associated pain and swelling, which varies based on the extent of the injury in the area.

In researcher Roxana Sarmadi’s 2020 study,^[29] pain and discomfort were higher with laser use compared to traditional techniques. This finding contrasts with most studies using lasers but supports our study, which found the modified technique superior to the traditional one. This discrepancy may be due to the use of the Er laser by Sarmadi, whereas other studies used the Nd laser.^[30]

Researcher Rakesh Kumar Yadav’s 2018 study, which compared Nd laser use to traditional scalpel techniques,^[31] found that pain levels were significantly higher with the traditional technique. This was explained by the traditional scalpel causing larger wounds, excessive bleeding, and the need for sutures, which is in contrast to our study using traditional surgery.^[32]

The strengths of this study lie in its comprehensive examination of pain, gingival inflammation, and scarring, all of which were notably reduced in the study group. However, the study faced limitations such as a relatively small sample size and the need for extended follow-up to fully assess long-term outcomes. Although some participants were children, and their experience of pain may have been expressed differently, VAS remains a standard method for converting subjective feelings into a measurable numerical rating.

Conclusions

The modified frenectomy technique, which incorporates a papilla protection flap, proves to be a highly effective approach for addressing the upper labial frenulum, particularly in cases where a gap exists between the incisors. This technique is advantageous in several key areas. Firstly, it significantly reduces the likelihood of scar formation in the sensitive papilla area, an important consideration for both aesthetic and functional outcomes. By preventing scar tissue buildup, it ensures better healing and maintains the natural appearance of the gingival tissue. Secondly, this method contributes to a reduction in postoperative pain, enhancing patient comfort and recovery. Overall, the use of a papilla protection flap not only improves the surgical outcome but also offers a more comfortable and aesthetically pleasing solution compared to traditional techniques.

Ethical approval

Board Name: Scientific Research Board Resolution – Tishreen University, Latakia, Syria (Board Status: Approval Number: 496. December 1st, 2021).

Consent

Written informed consent was obtained from the patients for publication of this study and accompanying images, a copy of the written consent is available for review by the Editor-in-Chief of Journal of Stomatology oral and Maxillofacial Surgery

Sources of funding

The study had no external sources of funding and therefore was in no way influenced by any sponsorship.

Author’s contribution

W.S.: first author, methodology, data analysis and interpretation; A.K.: supervision; N.S.: writing the paper, data interpretation.

Conflicts of interest disclosure

The authors confirm that there were no conflicts of interest.

Research registration unique identifying number (UIN)

Research Registry (esearchregistry10687).

Guarantor

Nadim Sleman.

Provenance and peer review

Not commissioned, externally peer-reviewed

Data availability statement

All data is available upon request.