Immediate rehabilitation of a palatal defected edentulous patient by implant-supported overdenture: a case report

Abstract

Background

Immediate rehabilitation is a considerable therapeutic challenge but is necessary for edentulous patients with oronasal fistulas, especially those with inadequate residual bone and a history of radiotherapy.

Case presentation

We report a rare case of a 63-year-old patient who was missing the majority of his maxillary teeth and who had a defect due to palatal mucoepidermoid carcinoma resection. The patient also received radiotherapy twice within one year postoperatively. An implant-supported prosthesis with an obturator was fabricated immediately.

Conclusion

This technique improved patients’ oral function, enhanced the aesthetic effect, and increased their confidence.

Background

Immediate rehabilitation is necessary and difficult for edentulous patients with palatal defects. Palatal defects can lead to the formation of an oronasal fistula, which, together with missing teeth, can lead to poor oral function and unsatisfactory aesthetic effects, thereby markedly decreasing quality of life [1, 2]. In addition, the psychological problems of patients should also be closely examined [3]. Traditionally, palatal defects have been treated via surgery or using an obturator prosthesis. However, surgical complications may occur, such as wound dehiscence and scar tissue formation. Additionally, the high success rate of obturators is not optimal when they are combined with an edentulous maxilla, especially among patients with insufficient bone quantity because of poor retention and stability [4].

Fortunately, many studies have confirmed that osseointegrated dental implants can considerably improve prosthetic retention and stability, oral function, and quality of life [1, 5, 6]. Compared with conventional obturator prostheses, implant-supported obturator prostheses have better oral function [4]. The literature indicates that implant-supported fixed dentures (IFDs) require more bone tissue than implant-supported overdentures (IODs) because more dental implants are implanted. Additionally, IFDs present a substantial challenge in oral cleaning and oral health. Therefore, IFDs have been considered inappropriate because of inadequate bone and oronasal fistulas [5, 7].

However, radiotherapy can lead to bone damage, affecting bone healing and osseointegration, which may play an important role in implant failure [6, 8].

To the best of our knowledge, few studies have examined immediate loading using only two implants in the upper jaw, especially combined with radiotherapy. Therefore, this clinical report presents a new procedure using four dental implants that were installed in two stages and an implant-supported overdenture (IOD) that was fabricated immediately for the immediate rehabilitation of an edentulous patient with a palatal defect and a history of radiotherapy.

Case presentation

A 63-year-old Chinese male who was missing the majority of his maxillary teeth and who had a palatal defect presented to the hospital complaining about the poor fit of his removable partial denture due to loss of teeth and due to the loss of peripheral seal when he forced a smile (Fig. 1). The oral examination revealed a 28 × 25 mm palatal defect. The patient had a history of palatal mucoepidermoid carcinoma resection, palatal radiotherapy at a dose of 50 Gy and maxillary majority tooth loss 8 years prior. This prosthesis was developed to replace the missing teeth and reconstruct the palatal defect to improve the patient’s physiological function and aesthetic effect.

Fig. 1.

Removable partial denture previously worn by the patient

At the initial visit, the patient was asked about his relevant medical history, a clinical examination and radiographic analysis were performed (Fig. 2), and oral and facial photographs were collected. An IOD was finally accepted by the patient through adequate communication about possible treatment options.

Fig. 2.

Clinical examination and radiographic analysis before surgery

On the basis of the preoperative design and the amount of attachment loss and mobility, the remaining maxillary teeth were deemed hopeless and were extracted. Two dental implants (SuperLine, Dentium, South Korea) (Table 1) were implanted in the maxilla (at positions #4 and #10) (Fig. 3). Primary stability was measured via a torque wrench (torque values > 35 Ncm). A transitional bar-retained IOD was fabricated and placed immediately after surgery to maintain the patient’s oral function and aesthetic effect (Figs. 4 and 5).

Table 1.

Distributions and dimensions of implants placed in the Maxilla

Implant Distributions	Implant Dimensions
#10	4.0 × 12 mm
#4	4.5 × 12 mm
#7	4.5 × 10 mm
#13	4.5 × 10 mm

Fig. 3.

First surgery to remove remaining loose maxillary teeth, place two implants (teeth #4 and #10)

Fig. 4.

A Silicone impression. B Working cast. C Articulator

Fig. 5.

Transitional overdenture. A Bars are connected to the implant abutments. B external surface. C tissue surface. D Frontal view. E and F Lateral view

Five months later, the patient hoped to have the two other implants placed in the desired position in the maxilla. After five months of natural healing, CBCT revealed that the bone in 2 maxillary teeth (teeth #7 and #13) was more suitable than other sites for implant placement (Fig. 6). The primary impression was made immediately using a silicone impression material (DMG Silagum, Hamburg, Germany) after the two other implants (SuperLine, Dentium, South Korea) (Fig. 7) (Table 1) had been implanted. Personalized transfer rods, which were connected to each other by a stainless steel wire, were attached to the corresponding implants to ensure accurate transfer. A personalized tray was manufactured using light-cured model materials (HUGE, Shandong Province, China) to make a final impression. The final impression was made using the impression material mentioned above. Dental implant analogues were inserted, and die stone was poured into the final cast (Kulzer, Indiana, USA). After the jaw relations and lip supports were checked, the milled bar was mechanically cut using pure titanium, the base portion of the restorations was made via thermal polymerization acrylic resin, and the blockers were fabricated via soft lining to close the palate defect (Fig. 8).

Fig. 6.

Cone beam CT after 5 months. A Tooth #7. B Tooth #13

Fig. 7.

Second surgery to place two other implants (teeth #7 and #13)

Fig. 8.

A Milled bar. B Working cast. C Articulator

The prosthesis was then inserted into the patient’s mouth, and retention, occlusion, speech, and fit were evaluated (Fig. 9). The patient was trained in the maintenance of the new prosthesis and was instructed in oral hygiene control. Additionally, the patient was required to be regularly evaluated every 6 months, and peri-implant maintenance was performed at each of those appointments. He was satisfied with the results in terms of enhanced aesthetic effects and improved oral function. The missing teeth #18 and #19 were subsequently replaced with two implants. After 1 year of follow-up, oral rehabilitation was stable, and the patient’s confidence improved (Fig. 10).

Fig. 9.

Final overdenture. A Bars are connected to the implant abutments. B external surface. C tissue surface. D Frontal view. E and F Lateral view

Fig. 10.

Panoramic radiograph taken after 1 year of follow-up

Discussion and conclusion

Immediate rehabilitation is necessary for edentulous patients, especially those with an oronasal fistula. The loss of teeth has a detrimental effect on mastication, speech, and aesthetics [9]. Additionally, adequate retention and stability of the prosthesis are difficult to obtain because of the loss of teeth, which is a major cause of patient complaints. Moreover, the oral nasal communication caused by surgical resection of malignant tumours results in difficult mastication and deglutition and reduced psychosocial function [6]. In this case, due to the loose remaining maxillary teeth and poor retention of the original prosthesis, the quality of life decreased. Therefore, immediate rehabilitation of missing teeth and sealing of the oronasal fistula are extremely important for this patient.

Immediate loading presents substantial therapeutic challenges due to inadequate residual bone in the maxilla, especially when combined with radiotherapy. The quality and quantity of the available residual alveolar bone and the primary stability of the implant after implantation have a strong influence on the success rates [10]. Additionally, radiotherapy plays an extremely significant role in oral implant failure. Impaired bone quality is also caused by radiotherapy, which compromises bone healing and osseointegration [6, 8]. In this case, the patient’s remaining maxillary teeth had a history of periodontitis, which was deemed hopeless; furthermore, he presented with grade III looseness and a history of radiotherapy, which increased the risk of infection and necrosis [11]. The patient was also dissatisfied with the original obturator prosthesis due to poor retention and stability and was expected to replace it with an implant-supported obturator. Furthermore, IODs have more advantages with respect to oral hygiene control than do IFDs, which is crucial for patients with a history of radiotherapy [5, 7, 12]. Nevertheless, only 2 sites were allowed for implant placement, and the remaining sites had insufficient residual bone and presented non-spacemaking bone defects, making it impossible to obtain ideal implant placement without extracting the affected tooth, according to radiographic analysis. Moreover, with the removal of the affected tooth, periodontitis can be controlled, thereby reducing the risk of osteoradionecrosis [12–14]. Thus, during the first surgery, the remaining loose teeth were extracted, and two long implants (12 mm) (teeth #4 and #10) were installed on the maxilla to improve primary stability. Because immediate loading using only 2 implants presented a high risk, the two other implants were placed in the desired area after more than 4 months of natural healing, although Kappel et al. suggested that 2 implants for the overdenture were optional in the upper jaw [15]. However, owing to the high risk and technical sensitivity of using only two immediate implants, strict selection of indications is necessary.

Bar attachment systems are traditionally used because of their relatively high stability [16]. In particular, milled bar-retained overdentures have a greater advantage in cases of moderate-to-severe maxillary resorption [17]. Current studies support immediate loading in oral reconstruction using an implant-supported bar-retained overdenture, although immediate loading in the edentulous jaw remains a challenge [18, 19]. The main reason is that not only can it improve chewing function and enhance the aesthetic effect, but it can also improve the quality of life of patients.

However, to decrease interference and improve success, high primary stability at implant placement should be achieved, and reducing the frequency of removal and insertion of overdentures during osseointegration is needed. Furthermore, experienced clinicians and detailed procedures are indispensable to ensure accuracy [6]. Additionally, depending on the patient’s condition, minimally invasive and personalized treatment options should be implemented.

The patient benefited from this technique, which provides a new treatment option for similar cases. However, owing to the limited number of such cases, 2 immediate implants were used in this case, but success may not have been achieved with this treatment plan in similar cases. Hence, further studies and more data are needed to validate this treatment.

Abbreviations

IFD

Implant-supported fixed denture

IOD

Implant-supported overdenture

Author contributions

BJX and XL contributed to the literature search, clinical studies, manuscript preparation, manuscript editing, manuscript review. BJX contributed to data acquisition, data analysis, patient follow-up. XL contributed to concepts, design, definition of intellectual content. All the authors have read and approved the final manuscript.

Funding

This study was supported by the “Feng Yuan” cooperation of Anhui Medical University (No. 2021kqxkFY10).

Data availability

All data supporting the findings is contained within the manuscript.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Written informed consent was obtained from the patient for publication of this case report and any accompanying images or radiographs.

Competing interests

The authors declare no competing interests.