Novel prosthodontic technique in fabrication of customized nasal stent in an infant

Abstract

Burn injuries have a major impact on the physical and functional aspects of patients, thereby affecting their quality of life. Nasal stenosis which occurs as a result of wound contraction may lead to serious complications if not intervened at the earliest. In the prosthodontic front, nasal stents may be utilized in conjunction with reconstructive surgery procedures to minimize scar contraction and prevent nasal stenosis. This clinical report focuses on a customized technique in the fabrication of nasal stent to maintain the nasal airway patency in an infant who had suffered burn injuries. An intraoral tip was employed as a receptacle for accurate impression making, followed by the insertion of an intermediate stent fashioned from a scalp vein set catheter. The definitive stent fabricated using methyl methacrylate resin served to maintain the patency of the nasal passageway.

INTRODUCTION

The nose is one of the most prominent features of the face. Due to its critical location and projected anatomy, it is often prone to damage from various congenital and acquired deformities.[1]

Sequelae of burn injuries have a major impact on the individual's psychological and social status. In addition, nasal stenosis which occurs as a result of burn injuries can lead to various consequences such as reduction in nasal diameter, reduced efficiency in nasal breathing, asymmetrical nostrils, oral breathing, dry mouth, susceptibility of oral mucosa to inflammation, and disturbance in cranial growth and development.[2] The treatment of an individual who has sustained extensive burns poses a challenge to the skills of professionals in various health care disciplines. In the prosthodontic front, nasal stents may be utilized in conjunction with reconstructive surgery to minimize scar contraction following skin grafting procedures or to counteract previously formed scar tissue and widen the nostrils prior to the grafting procedures.[3]

Nasal stents should be inserted early in the primary stage of healing. In case of narrowing, a serial nasal stenting protocol can be followed to gradually increase the nasal passageway.[4] The common feature in the construction of nasal stents is the use of burs to hollow out the stents for respiration. This is difficult and time consuming, especially when the impression takes a tortuous path.[5]

This case report highlights a technique in the fabrication of an individualized and custom-fashioned nasal stent for an infant who had suffered burn injuries. The prosthetic treatment goal was to maintain a patent nasal airway during the healing process with minimal discomfort to the patient.[6] A noninvasive, cost-effective, noncollapsible, and tissue-tolerant intraoral tip was employed as a receptacle for accurate impression making which was a prerequisite in the fabrication of the hollow nasal stent. Following the impression procedure, a novel, customized bilateral nasal stent fashioned out of a scalp vein set catheter was inserted.[7] Prior to the delivery of the definitive stent made of heat-cure methyl methacrylate resin, this immediate stent served to guard the patency of the nasal passageway.

CASE REPORT

A 10-month-old female child was referred to the Department of Prosthodontics from the Department of Plastic Surgery seeking prosthetic aid for the maintenance of patency of the nostrils. The patient suffered burn injuries all over the body due to accidental spill of boiling water 4 days prior and was admitted to the casualty ward with 51% burns on the face, trunk, and extremities. The patient was treated with split skin graft and dressing only at the chest and abdominal region. She was referred by the plastic surgeon for the fabrication of a nasal stent to prevent nasal stenosis resulting from wound contraction, facilitate proper breathing, and ensure internal airway patency.

On examination, the patient was alert, well-oriented, and in no acute distress. Close, visual inspection under direct lighting showed epidermal burn on the external surface of the nose and blanched areas. The nostrils were asymmetrical with constriction in relation to the right side. The skin was firm, free from discharge and eruptions [Figure 1]. No surgical intervention was performed on the nose as such.

Figure 1.

Preoperative photograph of the patient

Intranasal stent was fabricated taking into consideration the age, nasal esthetic subunits, and the comfort of the patient ensuring nontraumatic maintenance of the internal airway patency during wound healing.

The patient was seated upright on the parent's lap with the head supported on the parent's bosom and stabilized to prevent any untoward movement of the patient during the clinical procedures. This also helped in limiting the posterior-superior flow of impression material and avoiding distortion of the soft tissues during impression making of the nasal vestibule.

Intraoral tips (yellow mixing tips; Shreem Inc. India) [Figure 2] were inserted to an approximate length of the nasal vestibule and the dimensions were marked. Tray adhesive (Tray adhesive; Medicept UK Ltd, Middlesex, United Kingdom) was applied up to the demarcated portion of the tips and allowed to dry. The nasal cavity was smeared gently with petroleum jelly to facilitate the ease of insertion and removal of the impression. An impression of the nasal cavity was made with addition silicone heavy body (Reprosil, Dentsply Caulk, Milford, USA) using the demarcated intraoral tips as receptacles [Figure 3a and b]. The taper and contour of the tips served to conform to the anatomy of the nasal cavity. Care was taken not to force the impression material beyond the nasal cartilage. The impression of the right and left nasal cavities were made separately to avoid breathing difficulty [Figure 3c]. In addition, silicone putty (Elite P and P putty soft-normal set; Zhermack, Rovigo, Italy) was used to record the external anatomy of the nose including the columella, tip and the alae, and pick up the intranasal impressions [Figure 3d]. The putty impression, along with the intranasal impression, was retrieved and inspected for accuracy [Figure 4].

Figure 2.

Intraoral tips

Figure 3.

(a) Intranasal impression (right), (b) intranasal impression (left), (c) separate impressions of the right and left nasal vestibule, and (d) impression of the nose made using putty elastomeric impression material

Figure 4.

Complete impression of the external nose and nasal vestibule

A silicone scalp vein set catheter (Angle Scalp vein set; Devparv Surgico, Ahmedabad, India) [Figure 5a] conforming to the size of the nostril was bent into U-shape and cut according to the length and width of the columella to be inserted through the two nostrils [Figure 5b]. This served as an intermediate nasal stent until the definitive stent was fabricated for insertion [Figure 6].

Figure 5.

(a) Scalp vein set catheter, (b) customized immediate nasal stent

Figure 6.

Post insertion of the immediate nasal stent

The impressions of the external form of the nose and nasal passages were beaded, boxed, and poured with Type IV dental stone (Kalrock, Kalabhai Karson Pvt Ltd, Maharashtra, India) using the split cast technique. The intraoral tips were retained and secured in position to maintain the lumen of the nasal stent [Figure 7].

Figure 7.

Definitive cast poured with Type IV dental stone using split cast technique

The assembly was flasked and cured in heat-cure methacrylate resin (DPI Heat cure; Dental Products of India, Maharashtra, India) using split mold technique [Figure 8a] with different compartments to acrylize the stent [Figure 8b]. The definitive cast (split cast) was invested in the lower half of the flask, over which the index with intraoral tips was placed. The intraoral tips served to maintain the patency of the lumen throughout the acrylization procedure. After retrieval of the nasal stent, the intraoral tips were discarded. The stent was finished, polished [Figure 9a and b], and inserted with utmost care to avoid any insult to the delicate nasal mucosa ensuring the closest adaptation. The stent was self-retentive due to the projected intranasal portion and the winged extensions over the external surface of the nose.

Figure 8.

(a) Flasking of the assembly using split mold technique, (b) different compartments of the split mold

Figure 9.

(a and b) The definitive nasal stent finished, polished and inserted

The parents were educated on home care maintenance and usage of the prosthesis postinsertion. Proper cleansing and flushing of nasal secretions from the surface of the stent were demonstrated. Regular follow-up appointments were scheduled at regular intervals for 2 months and the postoperative results were satisfactory with adequate healing and least complications. Noticeable improvement of the nares was seen during the subsequent follow-up visits [Figure 10].

Figure 10.

Postoperative follow-up after 6 months

DISCUSSION

Nasal stenosis which occurs as a result of burn injuries can lead to various consequences if not treated promptly. Symmetry, contour, and function are the three goals of nasal reconstruction. Dorsum, lateral surface, alae, and the tip-columella complex which form the nasal esthetic subunits define the anatomy of the nose and must be given due priority in case of burn injuries.[8] A comprehensive reconstructive treatment plan must begin with a proper diagnosis and an understanding of prosthodontic treatment. The nasal stent must be stable and designed in such a way so as to maintain the patency of nasal cavity as well as negate the inevitable effects of gravity and distortion phenomena related to scarring.[2]

In the case presented here, owing to the minimal dimension of the nostrils, a customized receptacle was a challenge for impression making. The use of an intraoral tip with a tapering lumen and curved architecture helped serve the purpose to an effective extent. A customized impression technique using an intraoral tip helped us in omitting the tedious task of hollowing the stents using burs which would have caused deterioration of the stent. The laboratory technique was further simplified by using the elastomeric impression material as a model for stent fabrication, thereby eliminating dewaxing procedures. The functional and anatomical dimensions of the nose were given due importance throughout the treatment.

A vented custom made heat processed acrylic stent or silicone stent is commonly indicated in case of bilateral anterior obstruction in younger patients.[9] Hard acrylic stents are advantageous in that they are rigid, prevent collapse of the nasal wall, and can be precisely shaped, trimmed and polished to a smooth finish. They can accommodate slight undercuts and reportedly provide a scaffold for mucosal regeneration and minimize scar formation.[10] Although a few demerits such as long-term usage, low patient tolerance, and probability of mucosal irritation due to improper insertion exist, the merits outweigh them. Risk for dislocation and aspiration of the stent is also minimal in hard acrylic stents compared to surgical packs and silicone stents. Moreover, they are economical but their usage is limited to small defects in the anterior nasal cavity with nonstretchable nostrils.[2]

Although silicone stents are effective alternatives for nasal stenting in children, they are porous, friable, and lead to sorption of nasal secretions resulting in irritation of tissues from adhesion of mucus crust and tearing of the material. In addition, they can be prone to fungal growth and failure to achieve the goal of reconstruction. They may also require additional reinforcement within the lumen to prevent collapse of the nares during inhalation.

CONCLUSION

The prosthodontic treatment of burn injuries balances the seemingly disparate goals of establishing structure, improving contour, and esthetics as well as restoring the patency and function of the nasal airway. The treatment modality presented here helped serve the dual purpose of minimizing scar contraction due to burn injuries and also fend off surgical intervention as a consequence. The custom-fabricated nasal stent discussed here was self-retentive, atraumatic, and conformed well to the internal nasal passageway. This technique is not only conservative but also serves to prevent further complications like restenosis of the nasal passageway due to extensive wound contraction in the long run.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.