Gummy Smile Relapse After Lip Repositioning Surgery

Understanding Lip Repositioning and the Dynamics of Relapse

Lip repositioning surgery is an established periodontal plastic surgical procedure designed to treat excessive gingival display, commonly referred to as a gummy smile. The technique aims to restrict the upward pull of the elevator muscles of the upper lip by resecting a partial-thickness strip of maxillary labial mucosa and suturing the mucosal margin closer to the mucogingival junction. This shortens the vestibule and limits lip elevation during dynamic smiling, thereby reducing the amount of exposed gum tissue. When performed correctly, it delivers an aesthetic and harmonious smile line without altering the underlying bony facial framework.

Lip repositioning relapse occurs when the upper lip gradually returns to its preoperative position, leading to the reappearance of excessive gingival display during animated smiling. This phenomenon typically represents a loss of surgical restriction and re-elongation of the labial vestibule over time. While the surgery creates an immediate mechanical barrier to lip elevation, biological healing mechanisms, muscular adaptation, and tension across the surgical scar can counteract the initial surgical correction. Understanding the complex anatomy of the perioral musculature and soft tissue dynamics is fundamental to evaluating why relapse happens and how it can be revised.

Primary Aetiologies and Risk Factors for Relapse

The primary mechanism of lip repositioning relapse involves the strong, dynamic contractility of the upper lip elevator muscle complex. This group includes the levator labii superioris, levator labii superioris alaeque nasi, zygomaticus major and minor, and the levator anguli oris. If the surgical technique merely excises superficial mucosa without addressing muscle attachment or providing adequate periosteal anchoring, these powerful muscles can gradually stretch the immature scar tissue. Over several months, the scarred submucosa remodels and elongates, allowing the lip to regain its excessive vertical excursion upon full animation.

Surgical factors also play a critical role in early or late failure. Inadequate de-epithelialisation, improper surgical flap tension, or premature suture breakdown (dehiscence) can prevent dense fibrous union between the opposing mucosal borders. Furthermore, underlying skeletal disharmonies, particularly severe vertical maxillary excess (VME), represent a significant risk factor. When excessive gingival display is primarily driven by vertical overgrowth of the maxilla rather than hypermobility of the lip, soft-tissue surgery alone faces inherent mechanical limits and carries a substantially higher rate of partial or total relapse.

Systemic and environmental factors can further compromise tissue healing and stability. Habits that disrupt microcirculation and soft-tissue collagen synthesis—such as cigarette smoking, use of smokeless tobacco, gutka, and betel nut (paan)—severely impair mucosal wound healing. The mechanical irritation and chronic chemical trauma caused by paan and tobacco chew compromise tensile strength along the suture line, leading to micro-dehiscence and hypertrophic, non-elastic scar tissue that fails to maintain the restricted mucosal position.

Clinical Presentation and Recognition of Recurrent Display

Relapse presents as the progressive recurrence of visible gingival tissue above the maxillary teeth during natural and exaggerated smiling. In the immediate weeks following surgery, patients typically observe a significantly reduced gingival show, often accompanied by a temporary feeling of tightness or restricted mobility in the upper lip. As healing progresses, a relapsing case shows a gradual lessening of this restriction, with the smile line ascending back towards its baseline level. Relapse may be symmetrical, affecting the entire aesthetic zone, or asymmetrical, where one side elevates higher due to uneven muscle traction or localised suture failure.

Clinicians categorise the recurrence timeline into early relapse (occurring within the first six to twelve weeks postoperatively) and late relapse (manifesting between six months and two years). Early relapse is predominantly driven by surgical wound dehiscence, infection, or excessive early perioral movement pulling the sutured margins apart before initial fibroblastic maturation. Late relapse, conversely, is secondary to slow muscular re-adaptation, scar tissue elongation, and dynamic soft tissue remodelling against the continuous traction of everyday speech, mastication, and facial animation.

Diagnostic Evaluation and Comprehensive Smile Assessment

A thorough diagnostic evaluation is mandatory before planning any secondary intervention for lip repositioning relapse. The clinician begins with static and dynamic clinical measurements using a calibrated periodontal probe. Key parameters include the measurement of maxillary gingival display at rest, during a social (posed) smile, and during a spontaneous (Duchenne) smile. The clinician also assesses upper lip length at rest, interlabial gap, clinical crown dimensions, and the extent of vertical labial mobility from rest to full smile excursion to quantify perioral hypermobility accurately.

Radiographic imaging and photographic analysis are critical to isolate the underlying aetiology. Standardised extraoral photographs capture smile dynamics, while cone-beam computed tomography (CBCT) and lateral cephalometric radiographs evaluate skeletal discrepancies, vertical maxillary excess, and alveolar bone architecture. This differential diagnosis excludes coexisting conditions such as altered passive eruption (where gingiva covers anatomical crowns) or dentoalveolar extrusion, ensuring that revision therapy specifically targets the actual cause of relapse rather than repeating an inappropriate procedure.

Classification and Staging of Relapse Severity

Although standardised staging systems continue to evolve in the literature, excessive gingival display is widely classified according to the underlying anatomical driver and the vertical millimetres of exposed gum tissue. Mild display corresponds to 2 to 4 millimetres of exposed gingiva; moderate display involves 4 to 8 millimetres; and severe display exceeds 8 millimetres. In the context of postoperative relapse, clinicians determine whether the recurrence is partial (retaining some aesthetic improvement compared to baseline) or complete (returning fully to the preoperative display measurement).

Etiological subclassification is equally vital during relapse staging. Type I relapse is associated primarily with lip hypermobility and superficial scar elongation; Type II relapse is linked to underlying moderate-to-severe vertical maxillary excess that was under-addressed during primary surgery; and Type III relapse is combined with altered passive eruption or short anatomical crowns. Categorising the relapse ensures that the clinician does not perform isolated revision soft-tissue surgery when a combination of skeletal, periodontal, or restorative interventions is required.

Secondary and Revision Treatment Options

When managing lip repositioning relapse, clinicians consider both non-surgical and surgical modalities. Non-surgical management frequently involves botulinum neurotoxin type A injections targeting the levator labii superioris alaeque nasi and levator labii superioris muscles. Botulinum toxin provides a temporary, minimally invasive reduction in lip elevation by chemically blocking acetylcholine release at the neuromuscular junction. While effective for 3 to 6 months, it requires continuous re-treatment and does not offer a permanent structural solution.

Surgical revision options include modified revision lip repositioning, often combined with partial myectomy or myotomy (surgical disruption or detachment of the lip elevator muscle fibres) and rigid periosteal suturing. This technique provides stronger mechanical resistance against muscle re-attachment. Alternatively, if altered passive eruption is present, surgical crown lengthening with resective osseous surgery is combined with revision surgery. In cases where severe vertical maxillary excess is the true primary cause, orthognathic surgery—specifically a Le Fort I maxillary impaction—remains the gold-standard definitive intervention to reposition the bony base superiorly.

Step-by-Step Overview of Revision Surgical Repositioning

A revision lip repositioning procedure begins with local infiltration of an anaesthetic containing a vasoconstrictor to ensure patient comfort and optimal haemostasis. The surgeon carefully maps the anatomical boundaries, identifying the mucogingival junction and determining the width of mucosal excision, which is typically calculated as twice the desired vertical reduction in gingival display. Care is taken to preserve the anterior maxillary labial frenum when possible, or excise it cleanly if it contributes to abnormal central tension.

Two parallel horizontal incisions are made across the labial mucosa, connected by lateral vertical releasing incisions. The intervening epithelial band is meticulously de-epithelialised using sharp dissection, leaving the underlying connective tissue and periosteum intact. In a modified revision approach, the surgeon may perform a partial myotomy of the superficial fibres of the elevator muscles. The mucosal margins are then carefully approximated and stabilised with non-resorbable or slowly resorbable interrupted sutures anchored into the dense underlying periosteum, establishing a tension-free, stable, lowered mucosal border.

Postoperative Recovery, Wound Healing, and Aftercare

The postoperative recovery phase following revision lip repositioning is crucial for preventing a secondary recurrence. Patients typically experience moderate local swelling, perioral bruising, and a sensation of tension beneath the nose and upper lip during the first 7 to 10 days. Analgesics and anti-inflammatory medications are prescribed to manage discomfort. Ice packs applied extraorally in 15-minute intervals during the initial 48 hours help control oedema. A soft, non-chewy diet is strictly advised to avoid mechanical strain on the fresh mucosal sutures.

Proper wound care requires avoiding exaggerated facial expressions, wide smiling, and heavy talking during the initial two weeks. Patients must avoid retracting the lip to inspect the surgical site, as this introduces direct mechanical tension that can tear the sutures. Gentle oral hygiene with a 0.12% or 0.2% chlorhexidine digluconate mouthwash is recommended instead of mechanical toothbrushing over the surgical wound. Sutures, if non-resorbable, are typically inspected and carefully removed by the surgeon after 10 to 14 days.

Complications and Long-Term Management Strategies

Complications following revision surgery require prompt recognition and tailored management. Suture dehiscence represents the most frequent complication and directly correlates with relapse risk. If a small dehiscence occurs, conservative management with antiseptic rinses and secondary intention healing is often preferred over immediate resuturing, which can introduce excessive tissue tearing. Patients may also experience transient numbness or altered sensation (paraesthesia) of the upper lip and anterior gingiva, which generally resolves spontaneously over several weeks to months as micro-nerve endings regenerate.

Other potential complications include the development of small mucous retention cysts (mucoceles) if minor salivary glands are accidentally severed and buried beneath the sutured flap, as well as localized scar tissue formation that may feel firm to the tongue. Long-term management relies on continuous multidisciplinary monitoring involving periodontists, restorative dentists, and oral and maxillofacial surgeons. Regular recall visits at 1, 3, 6, and 12 months allow clinicians to document stability and address soft-tissue changes proactively.

Red Flag Symptoms Requiring Urgent Clinical Review

While mild swelling, moderate tenderness, and limited upper lip mobility are normal postoperative consequences, certain acute symptoms demand immediate clinical evaluation. Rapidly spreading facial swelling, intense erythema extending towards the infraorbital region or nose, and marked systemic symptoms such as fever or rigors indicate a potential secondary bacterial infection requiring prompt surgical drainage and targeted antimicrobial therapy. Patients must not delay seeking care if these infectious signs arise.

Other red flag symptoms include continuous, uncontrolled bleeding from the maxillary vestibule that does not subside with gentle pressure, sudden acute separation of the surgical wound margins (macroscopic dehiscence), or persistent, severe, non-subsiding sharp neuralgic pain. Sudden asymmetry accompanied by complete loss of motor function in perioral muscles also necessitates urgent specialist assessment to rule out deeper anatomical disruption or severe localised complications.

Evidence and further reading

The scientific consensus regarding lip repositioning and its stability is well documented across international periodontology and maxillofacial literature. Consensus reports from the European Federation of Periodontology (EFP) and the American Academy of Periodontology (AAP) emphasise that patient selection is the decisive factor in long-term surgical success. The literature consistently highlights that while lip repositioning provides significant aesthetic improvement for hypermobile lips, isolated mucosal repositioning carries an inherent risk of partial relapse if vertical maxillary excess is left unaddressed.

Systematic reviews published in mainstream journals, including the Journal of Clinical Periodontology, the International Journal of Oral and Maxillofacial Surgery, and the Journal of the American Dental Association (JADA), indicate that modified techniques involving muscle detachment (myotomy) or periosteal anchoring yield significantly higher stability than simple mucosal excision alone. Long-term follow-up studies reinforce that multidisciplinary assessment—combining periodontal, orthodontic, and orthognathic evaluations—is essential to achieve durable aesthetic outcomes and avoid recurrent excessive gingival display.