Unilateral hard palate necrosis following gingival injections with hyaluronic acid

Abstract

Hyaluronic acid (HA) injections into the oral mucosa have proven to be effective as a non-invasive method for the reconstruction of interproximal papillary defects in aesthetic areas. Despite being a minimally invasive and safe technique, certain side effects may occur after treatment.

We report the first case of a patient with unilateral necrosis of the mucosa of the hard palate after HA filling in the maxillary anterior gingiva. Familiarity with these events and competent knowledge of the anatomy is essential to avoid complications, achieve and offer adequate treatment and good results to our patients.

Background

Hyaluronic acid (HA) is a key element in the extracellular matrix of the different tissues of the oral cavity^{1 2}: it plays an important role in the downregulation of the inflammatory response as an inmunomodulator,³ it is part of different stages of tissue regeneration and wound healing⁴ and it has been shown that its viscoelastic characteristics reduce the penetration of microorganisms and their levels decrease in local infections.^{2 5} All this has led to the development of new applications of this component, promoting it as a topical agent in periodontal diseases, as well as an injected agent, increasing its use in the daily practice of dentistry and dental aesthetics.

It has also recently been proposed as a less invasive alternative procedure to resolve interproximal papilla loss. This procedure consists of filling the papillary base at the vestibular and sometimes palatal areas, in order to increase the volume and restore the lost gingiva.⁶ However, HA injection can also cause certain side effects, most of them related to the puncture at the injection site such as pain, bruising, itching and swelling, and others such as the appearance of granulomas, although these complications are not common.^7–9 We present the following case as a complication of an adverse effect of HA injection in the oral mucosa for the treatment of interdental papilla loss not described in the literature until now.

Case presentation

A woman in her 30s with no relevant medical history, no allergies and no drug or toxics intake, who came to the oral and maxillofacial surgery emergency department due to the development since 72 hours ago of a palatal hemi-mucosa lesion and intense associated pain. In the anamnesis, the patient reported a procedure 3 days ago consisting on several injections of HA gel at the second quadrant level, around the vestibular and palatal mucosa of an osseointegrated implant at the left central incisor space by a certified dentist in order to restore the interdental mucosa. She did not present odontalgia, fever or other associated symptoms.

Examination revealed palatal mucosa with necrotic appearance, painful on palpation, without evidence of signs that could suggest an intercurrent infectious process (figure 1).

Figure 1.

Photo showing friable and erythematous lesion at the left palate.

A complete nasal examination was performed to rule out mucosal necrosis, as well as a neuro-ophthalmological examination that ruled out retinal or cerebrovascular injury.

Investigations

An orthopantomography was requested in order to rule out intercurrent dental or bone processes (figure 2). Likewise, a blood analysis was performed where no significant alterations were evidenced.

Figure 2.

Photo showing osseointegrated implant at the left central incisor space.

As the patient’s symptoms began to resolve during the follow-up time period, no further investigations were undertaken.

Differential diagnosis

Palatal necrosis is a serious complication that is usually secondary to local trauma, infectious processes or drugs intake. It is frequently associated with other systemic diseases (diabetes, vasculitis, immunosuppressive deficiencies, malignant neoplasms) and, exceptionally, with other primary entities such as necrotising sialometaplasia.¹⁰

Due to the patient’s absence of medical history of interest, the non-use of drugs, the absence of systemic symptoms and the immediate recent history of HA injections in the oral mucosa, the rest of the diagnoses were ruled out.

Treatment

During her stay in the emergency room, intravenous analgesic treatment was started, with subsequent improvement of the pain and the patient could be discharged home with conservative treatment usin Non-steroidal anti-inflammatory drugs (NSAIDs) as well as antibiotic therapy (amoxicillin-clavulanic acid 500/125 mg every 8 hour) in order to avoid infection, in this case, the use of hyaluronidase was not considered because 72 hours had passed since the procedure.¹¹ A follow-up visit was scheduled in the following 7 days. However, the patient returned to the emergency room after 3 days due to persistent pain. On examination, the same clinical findings were evidenced without worsening of the lesion, so it was recommended to maintain the same treatment adding a descending corticotherapy regimen with oral methylprednisolone to achieve a supplementary anti-inflammatory effect.

Outcome and follow-up

A follow-up visit was carried out 1 week after the episode when the antibiotic treatment had already ended. The patient was able to control the pain with the prescribed analgesic drugs and additional treatment was not required. Physical examination revealed persistence of the necrotic palatal area in the process of granulation, with no signs of complications. A subsequent follow-up visit was scheduled in 1 month, once the descending corticotherapy regimen had finished, to assess the process of palatal granulation and resolution of the condition, however, the patient did not attend said appointment. Six months later, we scheduled a new follow-up visit in which the patient explained no further treatment required after our last visit and did not present any further complications. The palatal area was completely granulated with healthy mucosae as seen in figure 3.

Figure 3.

Photo showing complete complete regeneration of the mucosa after 6 months of the episode.

Discussion

HA is a mucopolysaccharide with an important role as a component of the extracellular matrix, produced mainly by mesenchymal cells.⁵ Its discovery in the vitreous humour of the bovine eye by Meyer and Palmer¹² gave rise to its subsequent clinical use by extracting it from rooster combs and then by extracting it from B. sutil cell culture factories.^{13 14}

Due to its potential as a tissue regenerator and volumetric filler, HA has been widely used in aesthetic medicine, as well as in dentistry. One of its particular applications is in its use as filling and reconstruction of the interdental papilla in interproximal defects in aesthetic areas,¹⁵ a technique first described by Becker et al.⁶

Due to their high biocompatibility, ease of use and reversibility, HA fillers are considered safe, but the rapid increase in their application has caused a higher incidence of complications.

One of the most feared complications is necrosis of the tissues adjacent to the injection as a result of an accidental intravascular injection and subsequent arterial or venous obstruction or even in less close territories due to embolisation. In addition, injection-related edema can compromise blood flow and contribute to vessel wall collapse.^{16 17} Although necrotising skin lesions have been well documented in the literature¹⁸, filler-induced ischaemic lesions of the oral mucosa have rarely been reported.

The irrigation of the oral cavity is given mainly by branches of the internal maxillary (IM) artery from the external carotid artery (EC).¹⁹ The complex functioning of the facial blood supply is discovered through the extensive anastomoses that exist between the different arterial systems.²⁰ Thus, there are cases in which the application of filler in the infraorbital area (also a branch of the IM artery) caused a posterior necrosis of the palatal mucosa²¹ due to its main irrigation of this mucosa through the descending palatine artery (MI).

It also explains the possibility of the travel of an embolus between the internal (IC) and EC artery systems, which through the ophthalmic artery (IC) can cause blindness due to the injection of filler in areas of the infraorbital artery (Maxillary internal).²² In fact, the irrigation of the hard palate is also given by the septal branches of the sphenopalatine artery (MI), which would explain not only the possibility of necrosis of the nasal mucosa, but also the anastomosis of the sphenopalatine artery with the ethmoid arteries of the ophthalmic artery (IC) could lead to ophthalmological complications and even brain damage.

There are also cases in which after the intraoral injections with local anaesthetics, especially those whose components included epinephrine, gave rise to posterior ischaemia and necrosis of the palatal mucosa.²³

In this article, we describe the first reported case of necrosis of the palate after the administration of a filling agent intraorally. In this case, possibly the proximity of the entrance of the greater palatine artery (descending palatine artery branch) in the incisive canal with the incisive papilla²⁰ caused the injection of the filling to cause its obstruction.

Patient’s perspective.

When I got into the emergency room, I was feeling so much pain that I could not bear it. After endovenous analgesia, I started to feel some relief, once I was feeling better I could go home with the prescribed drugs. During the first few days, the pain was persistent but it was after a week of the intervention when almost all the pain had disappeared and I could return to my normal life. I could stop taking pain killers after a week but I kept taking the corticoid therapy for a month. I was happily surprised that my rehab was so quickly and afterwards I haven’t had any pain nor problem at all.

Learning points.

• Practitioners who perform filler injections must have advanced knowledge of anatomy and be aware of high-risk regions that may experience complications.

• Due to the abundant blood supply of the palatal mucosa, this area should be avoided and used only in the vestibular area. Paying special attention to the papillae of the incisors due to their proximity to the incisive canal.

• Patients presenting with severe acute pain with tissue discolouration should be aware of the possibility of vascular occlusion.

• In such a scenario, the injection should be stopped and the area should be massaged and the use of hyaluronidase should be considered within 48 hours of the procedure. Refer to specialised emergency care if necessary.

• A complete regional inspection should be carried out to rule out, above all, involvement of the nasal mucosa and a neuro-ophthalmological examination is indicated to identify any retinal or cerebrovascular damage.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s).