The Journal of Indian Prosthodontic Society

CASE REPORT
Year
: 2022  |  Volume : 22  |  Issue : 4  |  Page : 405--409

Intraoral customized Z-spring-retained delayed surgical obturator for rare cases of bilateral subtotal maxillectomy


Anandmayee Chaturvedi, Kumari Deepika, Rekha Gupta 
 Department of Prosthodontics, Maulana Azad Institute of Dental Sciences, New Delhi, India

Correspondence Address:
Anandmayee Chaturvedi
Department of Prosthodontics, Maulana Azad Institute of Dental Sciences, Second Floor, New Delhi
India

Abstract

While dealing with a grave second wave of ongoing pandemic COVID-19, India also saw a surge in cases of COVID-19-associated mucormycosis, a systematic fungal infection caused by the Mucorales species. Mucormycosis is a highly angioinvasive, rapidly spreading fungal infection. In numerous cases of mucormycosis, bilateral subtotal maxillectomy was performed due to unpredictable and indefinable advancement of fungus clinically. Effective obturation of bilateral maxillectomy defect is a difficult task and as this is a relatively uncommon surgical problem, insufficient data are available on the construction of delayed surgical obturator for such cases. The aim of this article is to discuss the design of Z-spring-retained delayed surgical obturator which is easy to fabricate, easy to rectify, cost-effective, and comfortable for the patients compared to previous spring-retained obturators. This surgical obturator is retained through Z-spring made of 1.02 mm thick wire. Due to the thick gauge, this spring counters postsurgery trismus and develops the seal between the acrylic plate and dorsum of the tongue during deglutition thus helps the patient in taking a soft diet initially. Novelty in this case is the design of the spring, which makes it beneficial for both patient and prosthodontist.



How to cite this article:
Chaturvedi A, Deepika K, Gupta R. Intraoral customized Z-spring-retained delayed surgical obturator for rare cases of bilateral subtotal maxillectomy.J Indian Prosthodont Soc 2022;22:405-409


How to cite this URL:
Chaturvedi A, Deepika K, Gupta R. Intraoral customized Z-spring-retained delayed surgical obturator for rare cases of bilateral subtotal maxillectomy. J Indian Prosthodont Soc [serial online] 2022 [cited 2023 Feb 8 ];22:405-409
Available from: https://www.j-ips.org/text.asp?2022/22/4/405/357802


Full Text



 Introduction



While dealing with a grave second wave of ongoing pandemic COVID-19, India also saw a surge in cases of COVID-19-associated mucormycosis,[1] a systematic fungal infection caused by the Mucorales species. Mucormycosis is a highly angioinvasive, rapidly spreading fungal infection. Medications such as broad-spectrum antifungal agents such as amphotericin B and posaconazole and surgical intervention remain the mainstay for the management of mucormycosis. In numerous cases of mucormycosis, bilateral subtotal maxillectomy had to be performed due to unpredictable and indefinable advancement of fungus clinically. Effective obturation of bilateral maxillectomy defect is a difficult task and as this is a relatively uncommon surgical problem,[2] insufficient data are available on the construction of surgical obturator for such cases. Post removal of nasogastric tube, a surgical obturator should be provided as soon as possible to assist the patient in swallowing and speech as well as to reduce the psychological trauma of resection. Immediate surgical obturators often do not fit effectively as they are made using preoperative measurement and many times surgery is more extensive than planned. Therefore, it becomes essential to provide a functional delayed surgical obturator to the patient.

A 68-year-old male who was suffering from left sinonasal mucormycosis with palatal involvement and had undergone left subtotal maxillectomy with right inferior maxillectomy [Figure 1]a was referred to the prosthodontics department for fabrication of delayed surgical obturator 10 days after surgery. A multitude of factors come into play while rehabilitating a patient. As the wound was in the healing stage and the patient had periodontally firm mandibular teeth, a spring-retained delayed surgical obturator was planned until the defect stabilizes.{Figure 1}

Expectations from this delayed surgical obturator were to obturate the defect, help the patient in deglutition of liquid, and semisolid diet postremoval of a nasogastric tube, improve speech, and counter trismus after surgery. Another expectation was to reduce psychological trauma to the patient. Although spring-retained obturators[3] have been used to treat total maxillectomy cases, the spring used is complicated in design, very flexible, difficult to fabricate, and difficult to rectify in the patient's mouth also the V-shaped arm of the spring impinges on the pterygomandibular raphe (especially in patients who are not having the third molar in the oral cavity) but we developed a simple Z-spring-retained customized obturator, which is easy to fabricate, easy to rectify, and does not impinge on soft tissues hence comfortable to the patient. In the previous spring-retained obturator, the spring design was similar for all the patients irrespective of different Different Vertical dimension at rest (VDR) for different patients. In Z-spring-retained obturator, the length of diagonal arm was decided according to the rest position of every patient (VDR). So that when the patient is in rest position, the spring is in passive condition and not putting any extra force on mandibular teeth and arch.

 Procedure



Preliminary impression of both maxillary and mandibular arch was made using an irreversible hydrocolloid compound (Zelgan, Dentsply, Gurgaon, India) [Figure 1]b. The patient was handled with utmost care while recording the impression, as the surgical wound was raw and fresh. Personal protective gear was used during the procedure, impressions and casts were disinfected using glutaraldehyde disinfectant, and instruments were properly autoclaved to reduce cross-contaminationAfter disinfection, the impression was poured in gypsum Type III material (Dental stone, Kalabhai Karson, Mumbai, India) [Figure 1]cRecord base was fabricated on maxillary cast using auto polymerizing resin (DPI, Rudrapur, India) and occlusal rim was made using modeling wax (Y-dents, Delhi, India). As it was decided not to exert masticatory forces on surgical site until primary healing, so record base was fabricated after completely blocking the defect area in the cast. Thus, the maxillary obturator did not require hollowing as it did not have any extension in a defect. Teeth arrangement was also delayed for the same reason of not putting masticatory forces on defect area in the healing phaseJaw relation was recorded using a conventional method. First, Vertical dimension at rest (VDR) was recorded using the phonetics method which was 6.4 mm. Then, Vertical Dimension at occlusion was kept at 6.2 mm and the mandible was guided into centric relation using the chin point guidance method. Casts were mounted on a mean value articulator (Samit, Dento Kem, Faridabad, India). The purpose of this step was to record vertical dimension at rest and centric relation and fabricate the spring in this position so that spring is in passive position when the mandible is in rest positionSpring fabrication: Nineteen-gauge (1.02 mm thick), hard, round, stainless steel orthodontic wire (Samit, Dento Kem, Faridabad, India) was used to fabricate the spring. The reason behind using a 19-gauge wire was to fabricate a spring which is self-supported, can counter trismus followed after surgery,[4] and does not fracture easily. Z-spring has three components: two horizontal arms, one diagonal arm, and two spring coils. The length of horizontal arms was decided to be 15 mm, as a small portion of this arm would be embedded in auto polymerizing resin. At the end of horizontal arm, two small loops were made to engage auto polymerizing resin. It was decided to fabricate coils of 4 mm diameter so that coils can be opened and closed comfortably. Distance between both horizontal arms of spring (length of diagonal arm) was decided according to the jaw relation of the patient. Two such springs were prepared [Figure 2]aMandibular record base fabrication: Adams clasp was constructed on both mandibular first molars and pin head clasp was constructed between canine and first premolar to provide retention to the mandibular denture baseAttaching Z-spring with both record bases: The lower end of the spring was attached to the bridge of Adams clasp and the upper end of spring was attached to the maxillary record base plate using autopolymerizing resin, thus, the obturator plate is in a suspended position [Figure 2]b, [Figure 2]c, [Figure 2]d.{Figure 2}

After finishing and polishing, a delayed surgical obturator was delivered to the patient. Pressure indicating paste was used to relieve all the pressure points. The patient and attendant both were instructed on insertion and removal of obturator. The patient was also instructed on how to clean both obturator and surgical site postmeal. Recall visits were kept after 24 h, 1 week, 2 weeks, 4 weeks, and 3 months for further adjustments as the defect shrunk very fast. After 3 months of follow-up, the Z-spring did not fracture, did not cause any soft-tissue trauma, and helped in maintaining mouth opening, i.e., countered trismus postsurgery. The patient was quite comfortable with obturator and had increased oral intake following insertion of obturator, which resulted in a 5 kg weight gain in 3 months. For a definitive obturator, a two-piece magnet retained hollow removable obturator or bar-retained fixed prosthesis attached to zygomatic implant would be planned based on the patient's physical condition, healing, economic condition, and preference.

 Bio-Mechanical Principle



Desired qualities in the spring were sufficient strength not to fracture under cyclic load, counter the trismus, flexible when in function, and passive in rest position. Keeping this in mind, 1.02-mm thick wire was used[4] and two coils were made which makes the spring both strong and flexible enough to serve the function. In rest position, Z-spring is not compressed and keeps the jaws separated similarly to the physiological rest position. Thus, it helps in counteracting trismus followed after surgery. Both the coils help in opening and closing movements. Both the coils act simultaneously and permit jaw movements.

 Discussion



There is limited data on delayed surgical obturator fabrication of the patients who have undergone bilateral total maxillectomy[5] as it is a relatively uncommon surgical process and creates defects that are difficult to rehabilitate prosthetically.[6] Lack of retention, support, and stability are common problems encountered while constructing prostheses for such patients.[7] Irrespective of the final treatment options available, the most immediate matter to be addressed is adequate nutrition in the postoperative phase.[8] Usually, wire-retained immediate surgical obturators are difficult to manage due to massive surgical defects and continuous contracture of the wound. Hence, a removable delayed surgical obturator is the best solution for such situations. Extraoral aid for retention can also be used for such cases but they are less esthetic and not preferred by young patients, hence, it becomes important to find different intraoral retentive means. One such successful obturator design is a spring-retained surgical obturator that is retained through spring, this spring develops the seal between the acrylic plate and dorsum of the tongue during deglutition [Figure 2]e, [Figure 2]f, [Figure 2]g, thus, helps the patient in starting a soft diet right after removal of nasogastric tube. Although spring-retained obturators[3] have been used to treat total maxillectomy cases, the spring used is complicated in design, very flexible, difficult to fabricate, and difficult to rectify in the patient's mouth also the V-shaped arm of the spring impinges on pterygomandibular raphe (especially in patients who are not having the third molar in the oral cavity)[9] but we developed a simple Z-spring-retained customized obturator, which is easy to fabricate, easy to rectify, and does not impinge on soft tissues hence comfortable to the patient. In the previous spring-retained obturator, the spring design was similar for all the patients irrespective of different VDR for different patients. In Z-spring-retained obturator, the length of diagonal arm was decided according to rest position of every patient (VDR). Hence, when the patient is in rest position, the spring is in passive condition and not putting any extra force on mandibular teeth and arch.

In this obturator, we designed a Z-spring to connect the maxillary and mandibular denture base. This Z-spring is easy to fabricate and requires very less manipulation in the patient's oral cavity. The thickness of wire makes it a good choice postmaxillectomy as it counters trismus that follows surgery also it is flexible enough to permit mandibular movement. Such obturator was given in four patients and it required only a little effort in teaching insertion and removal of obturator to the patient. After 3 months of follow-up, the Z-spring did not fracture, did not cause any soft-tissue trauma, and helped in maintaining mouth opening, i.e., countered trismus postsurgery. The patient was quite comfortable with obturator and had increased oral intake following insertion of obturator, which resulted in an average 5 kg weight gain in 3 months. Masticatory forces, masseter muscular activity, duration of chewing cycle increases with increase in hardness of food,[10] as with this obturator patient was taking liquid and semisolid diet, it was easier to function due to softness of food and the obturator also did not require any kind of repair in the given time frame, thus saving procedure time and cost. Based on our practical experience while treating various patients with this obturator, the following indication, contraindication, and limitations of this obturator have been given. It would help clinicians in case selection.

Indication

Periodontally firm mandibular teeth[11]Adequate mouth openingManual dexterity

Contraindication

Reduced mouth opening which hampers insertion and removal of obturator easilyMandibular edentulous arch or mandibular periodontally compromised teethExostoses are present in the mandibular arch as it causes discomfort to the patientGeriatric patients or patients with neurological disorders who do not have sufficient manual dexterity.

Limitation

Manual dexterity is required to insert and remove the obturator.

A short-term solution as spring may fracture in a definitive prosthesis.

 Conclusion



This simple design can be useful to fabricate delayed surgical obturator in compromised total maxillectomy cases where sufficient retentive anatomic undercuts are not present. This design is a boon for such patients who want to avoid extraoral retentive aids to help retain the obturator in place.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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