CASE REPORT


https://doi.org/10.5005/jp-journals-10019-1373
International Journal of Prosthodontics & Restorative Dentistry
Volume 12 | Issue 3 | Year 2022

Hollowing of Delayed Surgical Obturator in Maxillectomy Defects Secondary to Mucormycosis in Post-COVID-19 Era: A Case Series


Kumari Deepika1https://orcid.org/0000-0001-8680-9297, Kriti Bansal2, Anandmayee Chaturvedi3, Rekha Gupta4

1-4Department of Prosthodontics, Maulana Azad Institute of Dental Sciences, New Delhi, India

Corresponding Author: Kumari Deepika, Department of Prosthodontics, Maulana Azad Institute of Dental Sciences, New Delhi,India, Phone: +91 9838728407, e-mail: deepika12031990@gmail.com

Received on: 28 October 2022; Accepted on: 23 December 2022; Published on: 30 March 2023

ABSTRACT

During the second wave of the coronavirus disease 2019 (COVID-19) pandemic in India, there was an increase in the surge of mucormycosis cases secondary to COVID-19 infection. Aggressive surgical debridement is the most common treatment modality opted for its treatment that leads to extended maxillary defects. Obturating such defects may be very challenging from a prosthodontic point of view, as larger defect sizes and fewer retentive areas make it difficult to retain the prosthesis. A delayed surgical obturator is a prosthesis that is placed 6–10 days after the surgery, mainly used to minimize postoperative complications. It reproduces the contour of the palate and allows the patient to resume a regular diet. It also assists in normal speech. But in large surgical defects, the increased obturator’s weight makes it uncomfortable and nonretentive for the patient, compromising its function. Consequently, in this case series, hollow bulb obturators are fabricated to decrease the weight of the prosthesis and to improve the function by establishing palatal contour. In case 1, hollowing was done using thermoplastic polyvinyl chloride (PVC) sheets and in case 2 acrylic shim was used. In both cases two-layer techniques were used, as in large defects if we use a single-layer technique it will either increase the weight of the prosthesis or may fail to create a palatal contour that further compromises the function. The techniques followed here are easy to use and less time-consuming.

How to cite this article: Deepika K, Bansal K, Chaturvedi A, et al. Hollowing of Delayed Surgical Obturator in Maxillectomy Defects Secondary to Mucormycosis in Post-COVID-19 Era: A Case Series. Int J Prosthodont Restor Dent 2022;12(3):149-154.

Source of support: Nil

Conflict of interest: None

Patient consent statement: The author(s) have obtained written informed consent from the patients for publication of the case report details and related images.

Keywords: Delayed surgical obturator, Hollow bulb obturator, Maxillectomy defect, Mucormycosis.

BACKGROUND

Mucormycosis, a rare fungal infection associated with diabetes, had become much more common as a result of the lethal cocktail of COVID-19 infection and the widespread use of corticosteroids in India. It is caused by the Mucorales fungi, which have an affinity for blood vessel walls. They grow quickly once they acquire access to the mucous membranes, invading surrounding blood vessels and causing vascular thrombosis and necrosis.1 The management includes surgical debridement of necrotic tissue with antifungal medication (amphotericin B, posaconazole, and isavuconazole; most common).2 Extensive maxillary defects may occur after surgical excision and debridement of the affected areas due to the invasive nature of mucor. Rehabilitation of such defects is extremely challenging. At the expense of its shape, size, and weight, the obturator is stretched vertically to engage the surgical defect and horizontally to contact the bony or soft tissue undercuts in larger surgical defects.3 Increased weight of the obturator can make it nonretentive due to gravity and endanger its function. As a result, hollow bulb obturators are made to reduce the prosthesis’ weight.

Based on Aramany’s classification, Wu and Schaaf4 constructed different types of obturator prostheses (both solid and hollow) and assessed them for weight reduction. They found that hollow obturator prostheses reduced weight by a significant amount, ranging from 6.55 to 33.06% depending on the size of the defect. To make open and closed hollow obturator prostheses lightweight, a variety of approaches have been described5-10 and most of these methods have their limitations, such as multiple processing techniques. In literature, these processes of hollowing of obturator were mostly done for fabrication of definitive prosthesis. Delayed surgical obturator is also a critical part of the rehabilitation of patients during an early postoperative period as it improves the contour of the palate aiding in speech and swallowing. Therefore, in this case series, different methods of hollowing of delayed surgical obturator were tried in patients with extensive maxillary defects secondary to mucormycosis.

CASE DESCRIPTION

Case 1

A 57-year-old male was referred to the Department of Prosthodontics from the ENT Department for fabrication of a delayed surgical obturator for an acquired defect of the maxilla after surgical debridement of mucormycotic necrosis. He had undergone bilateral subtotal maxillectomy under general anesthesia for the same. Detailed history reveals he had a history of COVID-19, steroids use, and diabetes for 4 years.

Intraoral examination revealed Aramany’s class IV defect (total maxillectomy with orbital contents intact) (Fig. 1A). The entire hard palate and teeth on both sides were resected with intact right second molar 17. A big communication was present between the nasal and oral cavities except for part of the nasal septum. Mild tissue inflammation was noted at the margins of the defect. The prosthetic challenge posed here was the absence of any anatomical features like a hard palate and adequate teeth for retention and support of conventional prosthesis. Delayed hollow surgical obturator was planned and fabricated using flexible two PVC sheets with hollowed portions between them.

Figs 1A and B: (A) Bilateral subtotal maxillectomy defect with retained tooth 17; (B) Working model poured from irreversible hydrocolloid impression

Primary impression was made with irreversible hydrocolloid material (Zelgan, Dentsply, Mumbai, India) and poured with type III gypsum stone (Kalabhai Kalstone, Mumbai, India) for the working model (Fig. 1B). A 2 mm thick thermoplastic PVC sheet (Huaer and original equipment manufacturer Dental Vacuum forming sheet, Henan province, Zhengzhou) was heated and pressed to model in defect area using vacuum machine (Biostar, Scheu-dental, Iserlohn, Germany). The margins of the PVC sheet were trimmed and finished to check in the patient’s mouth for retention by engaging undercuts in surgical defect. Relining was done around retained tooth 17 using autopolymerizing acrylic resin to improve retention. After that condensation silicone putty (Zhermack Dental, Badia Polesine, Rovigo, Italy) was adapted into the defect area over the first PVC sheet to create a palatal contour (Figs 2A and B). Then another PVC sheet (1.5–2 mm thick) was heated and pressed using the same vacuum machine (Fig. 2C). After this overlying PVC sheet was separated to remove silicone putty. Due to the thermoplastic properties of PVC sheets, both PVC sheets were adhered to each other by heating their peripheries over the flame (Figs 2D and E). Both sheets formed the hollow bulb portion of the obturator in between them. The adhesion parts were trimmed and polished using a silicon point and delivered to the patient (Fig. 3).

Figs 2A to E: (A) First thermoplastic PVC sheet adapted; (B) Condensation silicone putty adapted over PVC sheet to create palatal contour; (C) Second thermoplastic PVC sheet adapted over putty; (D) Both PVC sheets separated to remove putty in between them; (E) Both PVC sheets adhered to each other by heating their peripheries over flame

Fig. 3: Hollow delayed surgical obturator delivered

The patient was instructed about the insertion, removal, and maintenance of the prosthesis. The patient was also instructed to have liquid and semisolid food which doesn’t require mastication.

Case 2

A 51-year-old male patient was referred for the fabrication of a delayed surgical obturator for closure of his palatal defect after undergoing surgery for sinonasal mucormycosis with actinomycosis. He had a history of COVID-19, steroids use, and diabetes for 10–12 years. He had undergone a left subtotal maxillectomy under general anesthesia for the same. On extraoral examination, no gross asymmetry was noted and mouth opening was adequate. Intraoral examination revealed an extremely deep communication between the oral and nasal cavities and with retained inferior turbinate on the left side, which fell into the Aramany class I category, involving the hard and soft palate. The teeth present in the upper arch were 12–17 with missing teeth 11, and 21–27 (Fig. 4A). The devised prosthetic treatment plan was the fabrication of a hollow delayed surgical obturator to close the defect.

Figs 4A and B: (A) Aramany class I defect: intraoral view; (B) Working model

A primary impression was made with irreversible hydrocolloid material (Zelgan, Dentsply, Mumbai, India) and poured with type III gypsum product (Kalabhai kalstone, Mumbai, India) to fabricate the working model (Fig. 4B). Severe undercuts in the working model were blocked out with modeling wax (Rolex, Delhi, India). Base of the obturator was fabricated using autopolymerizing acrylic resin (Pyrax, Delhi, India) by utilizing the remaining teeth for retention using various clasps. Palatal contour was formed above the acrylic resin base using modeling wax. Acrylic shim was fabricated using autopolymerizing acrylic over that wax bulb. Then the wax bulb was removed for hollowing and the acrylic shim was joined to the underlying acrylic base using autopolymerizing acrylic resin to form a palatal contour (Fig. 5). After finishing and polishing, the obturator was delivered to the patient (Fig. 6). Patient was educated regarding the usage of the prosthesis. The patient was advised to remove the appliance while sleeping and to clean it after every meal.

Figs 5A to F: (A) Undercuts blocked out using modeling wax; (B) Base of obturator fabricated using autopolymerizing acrylic resin; (C) Palatal contour created above base using modeling wax; (D) Acrylic shim was fabricated; (E) Acrylic shim separated to remove wax for hollowing; (F) Acrylic shim was joined to underlying base using autopolymerizing acrylic to form palatal contour

Figs 6A to C: (A and B) Hollow delayed surgical obturator after finishing and polishing; (C) Obturator delivered to patient

Satisfactory results from hollow delayed surgical obturator were reported in both patients. A good deal of oroantral communication was achieved. The diet and phonetics of the patient were improved over time as noticed by the patient and by their caretakers and also observed at follow-up appointments.

DISCUSSION

There was an increased surge in the number of cases of mucormycosis during the COVID-19 pandemic. The extensive maxillary defects resulting from surgical debridement of necrotic tissues leave the patient with problems like difficulty in swallowing, mastication, and speech.11 These functional problems and facial disfigurement also have a psychological impact on patients.

Surgical rehabilitation after resection is claimed difficult due to deficient vital tissues and less patient acceptance for more such invasive procedures. Prosthetic rehabilitation starts immediately after the surgery with immediate or delayed surgical, after interim, and definitive obturators. Obturator forms a seal between the oral and nasal cavities, assisting patients in speech and swallowing. The first prosthesis placed is a surgical obturator, which is utilized to reduce postoperative problems. The goal of surgical obturator placement is to restore and preserve oral function in the postoperative period to a satisfactory degree. Immediate surgical obturators and delayed surgical obturators are two types of prostheses fulfilling this objective. Immediate surgical obturator would be ineffective in mucormycosis cases, as predetermining the extension of the lesion preoperatively may not be possible due to the invasive nature of the disease. These defects are allowed for epithelialization spontaneously, resulting in a nonkeratinized mucous membrane that provides a poor stress-bearing surface.12 Delayed surgical obturator is the only choice to rehabilitate such patients after surgery. Delayed surgical obturator prosthesis was usually fabricated with acrylic resin. In total maxillectomy cases, due to the absence of adequate hard and soft tissues for retention, it was very challenging for the maxillofacial prosthodontist to obturate such defects. Acrylic resin prosthesis was ineffective in such cases as no dentition is present to adequately stabilize the acrylic prosthesis with clasp and also the added weight of the prosthesis and effect of gravity compromises the retention. Therefore, the obturator should be made hollow to decrease the weight of the prosthesis. In such patients, the obturator made with PVC sheets could be an effective solution in the early postoperative period. PVC sheets show better adaptation and good stability by engaging the undercuts in the periphery of the defect, light in weight, monomer-free, and nonporous in nature when compared to acrylic. Patients were able to maintain a hygienic wound site due to the simplicity of insertion and removal, which allowed for easier surveillance.

In this case series, in case 1 delayed hollow surgical obturator was fabricated for bilateral maxillectomy defect using a PVC sheet. Retention was increased in this case due to retained tooth 17 by surgeons. A similar technique was used in some previous studies. Nakamori et al.13 created a temporary obturator with a 3 mm thick underlying layer and a 1.5–2 mm thick covering layer of ethylene vinyl acetate sheet (EVA) adapted to cast using positive and negative pressure methods, respectively. Johnson et al.14 show the utilization of a custom-made EVA interim obturator for subtotal and total maxillectomies. When compared to the immediate acrylic surgical obturator, he found that all three patients agreed that the interim EVA obturator provided a greater function for speaking and eating. In case 1, the patient has used the obturator for almost 6 months before going for a definitive obturator. After that time period, the obturator becomes somewhat rigid and friable. Distortion of prosthesis might be there that can be avoided by proper handling of the prosthesis. As delayed surgical obturator has to be given for a short period of time, therefore this treatment choice can be a better option due to the merits conferred by it.

In large partial maxillectomy cases, the obturator can be fabricated in a conventional manner from acrylic resin utilizing remaining teeth and undercuts for retention of the prosthesis, and should be made hollow to aid retention and make the prosthesis comfortable for the patient. The hollow obturator can be opened and closed. Open hollow bulb obturators are disadvantageous in collecting mucous, oral fluids, and food particles. In the literature, various methods for constructing closed-hollow obturators have been documented. However, these techniques are most commonly utilized for interim or definitive obturation in which the prosthesis is primarily made of heat cure acrylic resin.5,7,10

Here in the second case, a delayed surgical obturator was fabricated using autopolymerizing acrylic resin, and to make the prosthesis lightweight, it was hollowed out by using a wax bulb in defect portion and then covered by acrylic shim to restore palatal contour after removing the wax bulb. Due to the use of autopolymerizing resin, it has certain disadvantages of being more porous and getting easily stained. As during the second wave of COVID-19, there was an abrupt increase in mucormycosis cases leading to more workload on maxillofacial prosthodontists, moreover, in mucormycosis cases, defects show tissue contraction faster11 that leads to a change in defect size in very short period of time, so there was a need to make obturator prosthesis repeatedly within few weeks. Despite its little novelty, consequently, prosthesis using autopolymerizing resin can be given in such challenging times as it was easy, less time-consuming, and only have to be given for a short period. Watertight closure can be facilitated by roughening a small area of the autopolymerizing resin surface surrounding the window openings, then cleaning and wetting it thoroughly with the autopolymerizing acrylic resin monomer before sealing. There are many advantages of the hollowing technique for the fabrication of closed hollow bulb delayed surgical obturators in positively improving the retention by reducing the weight of the prosthesis and by negotiating the effect of gravity. The techniques described here are easy to use, reduce laboratory time, and make the procedure simple. The novelty of this case series is that the thickness of the hollow bulb can be controlled and lightweight prosthesis can be fabricated, especially while using thermoplastic vacuum-formed sheets. The thermoplastic vacuum-formed sheet as a delayed surgical obturator is a better option in bilateral maxillectomy defects where retention is difficult to achieve using a conventional method.

ORCID

Kumari Deepika https://orcid.org/0000-0001-8680-9297

REFERENCES

1. Lionakis MS, Kontoyiannis DP. Glucocorticoids and invasive fungal infections. Lancet 2003;362(9398):1828–1838. DOI: 10.1016/S0140-6736(03)14904-5

2. Pilmis B, Alanio A, Lortholary O, et al. Recent advances in the understanding and management of mucormycosis. F1000Res 2018;7(F1000 Faculty Rev):1429. DOI: 10.12688/f1000research.15081.1

3. Beumer J, Curtis T, Marunick M. Maxillofacial rehabilitation: prosthodontic and surgical considerations. St Louis: Ishiyaku EuroAmerica, Inc. 1996:240–285.

4. Wu YL, Schaaf NG. Comparison of weight reduction in different designs of solid and hollow obturator prostheses. J Prosthet Dent 1989;62(2):214–217. DOI: 10.1016/0022-3913(89)90317-x

5. Rani S, Gupta S, Verma M. Hollow bulb one piece maxillary definitive obturator - a simplified approach. Contemp Clin Dent 2017;8(1):167–170. DOI: 10.4103/ccd.ccd_887_16

6. Shaker KT. A simplified technique for construction of an interim obturator for a bilateral total maxillectomy defect. Int J Prosthodont 2000;13(2):166–168. PMID: 11203627.

7. Palmer B, Coffey KW. Fabrication of the hollow bulb obturator. J Prosthet Dent 1985;53(4):595–596. DOI: 10.1016/0022-3913(85)90658-4

8. Parel SM, LaFuente H. Single-visit hollow obturators for edentulous patients. J Prosthet Dent 1978;40(4):426–429. DOI: 10.1016/0022-3913(78)90126-9

9. Cheng AC, Somerville DA, Wee AG. Altered prosthodontic treatment approach for bilateral complete maxillectomy: a clinical report. J Prosthet Dent 2004;92(2):120–124. DOI: 10.1016/j.prosdent.2004.04.020

10. Mohamed K, R FB, Mahesheswaran, et al. Delayed surgical obturator-case series. Indian J Surg Oncol 2020;11(1):154–158. DOI: 10.1007/s13193-019-00992-9

11. Raut A, Huy NT. Rising incidence of mucormycosis in patients with COVID-19: another challenge for India amidst the second wave? Lancet Respir Med 2021;9(8):e77. DOI: 10.1016/S2213-2600(21)00265-4

12. Kurrasch M, Beumer J 3rd, Kagawa T. Mucormycosis: oral and prosthodontic implications. A report of 14 patients. J Prosthet Dent 1982;47(4):422–429. DOI: 10.1016/s0022-3913(82)80095-4

13. Nakamori K, Yamagishi M, Takaya K, et al. Effectiveness of a custom-made temporary obturator after bilateral total maxillectomy. Surg Sci 2013;4:322–324. DOI: 10.4236/ss.2013.47063

14. Johnson JM, Maida BD, Bishop R, et al. The use of a custom-made ethylene vinyl acetate interim obturator for sub-total and total maxillectomies. A report of 4 cases. J Oral Maxillofac Surg 2016;74(9):E83. DOI: 10.1016/j.joms.2016.06.147

________________________
© The Author(s). 2022 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and non-commercial reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.