Two-Piece Maxillary Hollow Obturator Retained by Mini Magnets: A Case Report

INTRODUCTION

 Defects in the maxillary arch vary in size, shape, and location according to the anatomical variation, extent of tumor resection or wound due to road traffic accidents or gunshots in a variety of patients.1 In cases of tumor resection, maxillary obturators are mostly given in three main phases: a surgical obturator, which is provided just after the surgery and fabricated on a pre-surgical cast. Secondly, after the initial wound healing, the surgical obturator is mostly relined and converted into interim prostheses after one to two weeks and used during the phase of healing and radiation for a period of approximately six to twelve months. Lastly, once the healing and treatment are complete, the definitive prosthesis is finally constructed.2 Most frequently, obturator prostheses are associated with a lack of retention and stability.3 The success of removable maxillary obturator prostheses mostly depends upon the remaining palatal bony and natural tooth support. Every effort must be exercised to conserve the palatal and vomer bone so that retention and support can be gained for removable prostheses. For a better prognosis, the maxillofacial prosthodontist, as a team member, must be consulted for the fabrication of the surgical obturator and surgical marking discussed so as to limit the sacrifice of crucial hard and soft tissues without compromising complete removal of the tumor.⁴

CASE REPORT 

History

A 55-year-old retired patient was referred from maxillofacial surgery OPD to the Division of Prosthodontics at Baqai Dental College, Baqai Medical University. With the chief complaint of inability to drink, nasal regurgitation, hypernasality, and aesthetic issues.

Examination

Clinical examination revealed that the patient had large  maxillary defect on his right side of maxilla. Only the right lip with contracture and scar tissue without any support was present. Patient had only 23, 25 and 26 Present with mouth opening only restricted to one figure. He was diagnosed with Squamous cell carcinoma on the right side of maxilla 2 years back in 2021 and had undergone hemi-maxillectomy for the same quadrant only some part of left maxilla saved. He also revealed that post-surgery, prosthesis was fabricated twice, which were loose and with no success. A single piece hollow definitive obturator was also fabricated 6 months after the surgery, but patient never used the prostheses as the patient was unable to insert the prostheses and had lack of retention.

Treatment

protocol Preliminary impression was made with the help of alginate using altered plastic stock tray after obturating the defect area with surgical gauze with dental floss tied to that so the impression tray can be easily retrieved. A sectional tray was fabricated held with tich buttons in two parts so that the final impression could be made easily in two segments 1st the defect part in putty consistency (Picture 2B) and the other dentate part in medium body polyvinyl siloxane. The impression was retrieved out of the patient's mouth in two parts because the limited opening of the mouth didn't allow one piece impression to be withdrawn from the mouth and again joined together outside the mouth and poured in dental stone. Once the impression was poured a two-part hollow

Picture 2: Clinical picture showing alginate impression with protruding form nasal cavity due to maxillary defect (A), Segmented impression of dentate part in medium body polyvinyl siloxane (B, C), Two segments joined together outside of the mouth by mini magnets, only three shadow of magnets visible as marked and fourth one is embedded in hollow obturator (D)

obturator was planned joined together by 4 mini magnets. (Picture 2D) A jaw relation was established, and the prosthetic teeth were positioned to allow unrestricted movement in

Picture 4: Insertion of acrylic plate and clasp of final restoration (G) Dentate part over first part through magnet (H), Extraoral clinical presentation of final restoration (I)

 both centric and eccentric movements. (Picture 3) A trial was then conducted to ensure proper fit and function. The final processed denture was delivered to the patient in two parts retained by mini magnets strategically placed. Final delivered prostheses as seen in the Picture 4.

DISCUSSION

There are multiple problems in patients having maxillary defects such as lack of retention of prostheses, nasal regurgitation, hyper nasal speech, difficulty inserting the prostheses due to limited mouth opening and difficulty in mastication and swallowing.4-5 In this case the patient had a very limited amount of soft and hard tissue present, and the scar tissue had formed at the right side of lip with very limited mouth opening due to postoperative radiation therapy. For that reason, the patient had failed prostheses six months back which was made 18 months after the surgery. As it was a one-piece obturator, it was very difficult for the patient to insert and remove the prostheses and once inserted, with  quite difficulty he was unable to insert anything in mouth to eat or drink due to limited mouth opening.

While dealing with patients having limited mouth opening and maxillary defects, conventional impressions are very difficult to make and withdraw from the mouth in one piece. Sectional impression technique was used to make an impression in two parts and assembled outside the mouth.6 For this purpose, a sectional impression tray was fabricated, joined together with snap button/ pair of metallic interlocking discs. Same is the problem with the prostheses so a two-part hollow bulb maxillary obturator is an easy way to solve the problem which were joined together in mouth with the help of mini magnets.7 The four mini magnets were strategically placed in both parts and provide reasonable retention between two parts of denture. The first part was made hollow and it obturated the defect part which prevents hypernasality and regurgitation of fluids and liquids from the nasal cavity. The second part takes up the teeth for aesthetic purposes and lip support.⁸

There are certain limitations in this case such as the implant could be placed in the zygomatic or vomer bone, but the amount of the bone and quality was not adequate due to tumor resection and rotation therapy. Digital impressions of the defect could be made, and computer aided designing and manufacturing of the prostheses could have been done. But this facility was not available for such prostheses in the center.

CONCLUSION

 Limited mouth opening, scar tissue formation, accurate impression making, designing, and manufacturing of prostheses and lack of retention, support and stability are all the problems which are encountered during manufacturing of prostheses for hemi-maxillectomy patients. Sound knowledge and high level of technical skills are required to overcome all these problems which are dealt in scientific and logical manner. If any step in the process is ignored results are unacceptable for the patient and clinician as well. This treatment was aimed towards providing solutions to the problems faced by the patient that was nasal regurgitation, hoarseness of voice, inability to insert and remove the prostheses, esthetics, and function. All these problems were partly solved initially. Reconstructive surgery was suggested to the oral and maxillofacial surgeon. And lip prostheses will be incorporated in the future to address the problem of esthetics.

CONFLICT OF INTEREST

None to declare

REFERENCES

1. Fatani B, Alhilal AI, Alzahrani HH, Alkhattabi RR, Alhindi M, Alhilal A. Facial Reconstruction Using Facial Artery Myomucosal Flap: A Comprehensive Review. Cureus. 2023;15. https://doi.org/10.7759/cureus.42060
2. Dalkiz M, Dalkiz AS. The Effect of Immediate Obturator Reconstruction After Radical Maxillary Resections On Speech And Other Functions. Dent J. 2018;6:22. https://doi.org/10.3390/dj603002
3.  Semple CJ, Rutherford H, Killough S, Moore C, Mckenna G. Long Term Impact of Living With An Obturator Following A Maxillectomy: A Qualitative Study. J Dent. 2019;90:103212. https://doi.org/10.1016/j.jdent.2019.103212
4. Neeraj K Chandraker. Incremental Impression Technique for Maxillary Obturator Prosthesis Fabrication: Case Series. Int J Prosthod Restorative Dent, Volume 12 Issue 1 (January-March 2022). https://doi.org/10.5005/jp-journals-10019-1349
5. Ishita Dureja, Ripul Pahwa , Akshay Pahwa, Ritika Satija. Maxillary Obturator in Hemi Maxillectomy Patient: A Case Report. OHDM Vol. 21 - No. 2 - February, 2022.
6. Shams SH, Shams SS, Ghasemi E. A Sectional Complete Denture for Microstomic Patients. Dent Res J. 2020;17:162. https://doi.org/10.4103/1735-3327.280895
7. Mahnaz Arshad, Gholamreza Shirani, Xaniar Mahmoudi. Rehabilitation after Severe Maxillectomy Using A Magnetic Obturator (A Case Report). Clin Case Rep. 2018;6:2347-2354. https://doi.org/10.1002/ccr3.1874
8. Kumar B, Minallah S, Maqsood A. Maxillofacial Defect Resulting From Mucormycosis Rehabilitation With A Magnetic Retained Facial Prosthesis And Obturator. Altamash J Dent Med. 2022;1:88-92.