McCarthy CE, Field JK, Rajlawat BP Trends and regional variation in the incidence of head and neck cancers in England: 2002 to 2011. Int J Oncol. 2015; 47:204-210 https://doi.org/10.3892/ijo.2015.2990
Anderson G, Ebadi M, Vo K An updated review on head and neck cancer treatment with radiation therapy. Cancers (Basel). 2021; 13 https://doi.org/10.3390/cancers13194912
Banerjee S, Kumar S, Bera A Magnet retained intraoral-extra oral combination prosthesis: a case report. J Adv Prosthodont. 2012; 4:235-258 https://doi.org/10.4047/jap.2012.4.4.235
Cordeiro PG, Santamaria E A classification system and algorithm for reconstruction of maxillectomy and midfacial defects. Plast Reconstr Surg. 2000; 105:2331-2346 https://doi.org/10.1097/00006534-200006000-00004
Brignoni R, Dominici JT An intraoral-extraoral combination prosthesis using an intermediate framework and magnets: a clinical report. J Prosthet Dent. 2001; 85:7-11 https://doi.org/10.1067/mpr.2001.113030
Guttal SS, Patil NP, Shetye AD Prosthetic rehabilitation of a midfacial defect resulting from lethal midline granuloma – a clinical report. J Oral Rehabil. 2006; 33:863-867 https://doi.org/10.1111/j.1365-2842.2006.01616.x
Cowan PW An obturator prosthesis. Quintessence Int. 1985; 16:403-405
Patil PG, Patil SP Fabrication of a hollow obturator as a single unit for management of bilateral subtotal maxillectomy. J Prosthodont. 2012; 21:194-199 https://doi.org/10.1111/j.1532-849X.2011.00799.x
Sharma AB, Beumer J Reconstruction of maxillary defects: the case for prosthetic rehabilitation. J Oral Maxillofac Surg. 2005; 63:1770-1773 https://doi.org/10.1016/j.joms.2005.08.013
Somay E, Yilmaz B, Topkan E Radiotherapy and dental implant applications in patients with head and neck cancer. In: Sergi CM Brisbane, Australia: Exon Publications; 2023
Engelen M, van Heumen CC, Merkx MA, Meijer GJ Intraoral-extraoral combination prosthesis: improving retention using interconnecting magnets. Int J Prosthodont. 2014; 27:279-282 https://doi.org/10.11607/ijp.3849
Menneking H, Klein M, Hell B, Bier J Prosthetic restoration of nasal defects: Indications for two different osseo-integrated implant systems. J Facial Somato Prosthet. 1998; 4:29-33
Thomas KLondon: Quintessence Publishing; 1994
Worthington P, Bränemark PI Advanced Osseo-integration Surgery Applications in the Maxillofacial Region.Il, USA: Quintessence; 1992
Sykes LM, Essop RM Combination intraoral and extraoral prosthesis used for rehabilitation of a patient treated for cancrum oris: a clinical report. J Prosthet Dent. 2000; 83:613-616
Hatami M, Badrian H, Samanipoor S, Goiato MC Magnet-retained facial prosthesis combined with maxillary obturator. Case Rep Dent. 2013; 2013 https://doi.org/10.1155/2013/406410
Roumanas E, Nishumura R, Beumer J Osseo-integrated implants: six-year follow-up report on the success rates of craniofacial implants at UCLA. Int J Oral Maxillofac Implants. 1994; 9:579-585
Butterworth C, McCaul L, Barclay C Restorative dentistry and oral rehabilitation: United Kingdom National Multidisciplinary Guidelines. J Laryngol Otol. 2016; 130:(S2)S41-S44 https://doi.org/10.1017/S0022215116000414
Drago CJ Tarnish and corrosion with the use of intraoral magnets. J Prosthet Dent. 1991; 66:536-540
Patil PG Modified technique to fabricate a hollow light-weight facial prosthesis for lateral midfacial defect: a clinical report. J Adv Prosthodont. 2010; 2:65-70 https://doi.org/10.4047/jap.2010.2.3.65
The rehabilitation of a combined mid-facial defect using a magnetretained intra- and extra-oral prosthesis: a case report Hollie Hawrot Rachael Y Jablonski Zaid Ali Dental Update 2024 51:7, 707-709.
There are several treatment options available to restore function and appearance in patients with combined mid-facial defects. Owing to the size of the defect and the associated size and weight of the prostheses, adequate retention can be challenging to achieve. Retention of a facial prosthesis can be improved using several techniques, such as medical grade adhesives, attachments, or osseo-integrated implants. For patients with a history of radiotherapy, surgical rehabilitation may be less favourable than non-surgical approaches owing to the risk of osteoradionecrosis and a reduced blood supply in the surgical fields. This clinical case report highlights the conservative rehabilitation of a combined mid-facial defect using a magnet-retained intra-oral and extra-oral prosthesis.
CPD/Clinical Relevance:
A thorough medical and clinical assessment will highlight factors that will influence the treatment planning process when managing a combined mid-facial defect.
Article
Malignant tumours that arise from the paranasal sinuses, salivary glands and upper aerodigestive tract are classified as head and neck cancers (HNC).1,2 In 2008, there were over 500,000 cases of HNC worldwide, of which, around 6000 of these cases occurred in the United Kingdom.2 Current data show an upward trend in HNC and, as the eighth most common type of cancer currently in the UK, the treatment and rehabilitation of HNC will become more common practice.3 The primary treatment modalities for HNC are surgery, radiotherapy, chemoradiotherapy, or a combination treatment.4 In cases where surgical intervention is required and the tumour resection is large, a mid-facial defect may be a consequence.4
Mid-facial defects are classified as defects that are confined to the middle third of the face in the horizontal plane and communicate with intra-oral maxillary defects.5 Inevitable consequences of mid-facial defects include functional difficulty and significant disfigurement.6 Some confusion exists over the classification of mid-facial defects owing to the presence of multiple classification systems and the amalgamation of mid-facial defects with maxillectomy defects. Furthermore, a standardized approach to apply to the reconstruction of mid-facial defects is lacking.7 However, local classifications do exist, such as the classification made by the Memorial Sloan–Kettering Cancer Center, which describes four broad types of facial defects based upon the extent of resection of the maxillary walls, palate, and orbital contents.7
Significant psychological and physical implications are commonly seen in patients with mid-facial defects as a result of the aesthetic changes and the considerable functional impact on swallowing, mastication and speech. Owing to the proximity of vital anatomical structures, mid-facial defects are often complex because maxillary bone is commonly resected along with tumours that originate from the intra-oral mucosa, overlying skin, palate, nasal cavity, orbital contents and paranasal sinuses.7 Therefore, an extensive knowledge of intra- and extra-oral anatomy and careful planning is essential to ensure satisfactory rehabilitation of mid-facial defects.7
Rehabilitation options include surgical or prosthetic rehabilitation, or a combination of the two. Prosthetic rehabilitation is often the preferred treatment modality to improve aesthetics and function, particularly in scenarios where surgery is deemed unsafe for the patient, or where it is not possible to adequately repair the defect alone.5,8,9 Where the tumour of origin and subsequent defect is large, prosthetic rehabilitation normally comprises a combination of an intra-and extra-oral prosthesis.
The intra-oral prosthesis will aim to improve mastication, speech and aesthetics by preventing food, liquid and air from escaping into the nasal cavity or maxillary sinus.10 Consideration will need to be given towards modifying impression techniques, prosthesis design, connector path of insertion, aesthetics and maintenance regimens to account for the complex nature of mid-facial defects.6 A facial prosthesis can be produced for a patient to improve aesthetics, function and quality of life.5 Although prosthetic rehabilitation of mid-facial defects is a less invasive treatment modality than surgery, the production of an acceptable facial prosthesis is complex and relies heavily on maxillofacial prosthetist skills and experience.6,11
In cases with little or no residual maxillary structure, it can be difficult to achieve adequate retention, support, and stability for prostheses. Prosthetic modifications by extending the obturator into the lateral wall of the defect may help to prevent leakage, support the soft tissues, and aid replacement of teeth.12 The use of osseo-integrated implants to aid retention of extra- and intra-oral prostheses is well supported in the literature; however, patients with mid-facial defects may be unsuitable for implant placement owing to previous radiotherapy in the area. While implant placement is often successful following radiotherapy, dental implant surgery to sites of interest is complicated at doses exceeding 50 Gy, the dose at which osteoblasts are susceptible to cell death.13 In such cases, adequate rehabilitation is more difficult to achieve.14
Although complex, the construction of intra-and extra-oral prostheses that mutually retain each other is possible, and the literature has described several methods to enhance retention. For example, by using eye patches, eyeglasses, extension of the prostheses into desirable undercuts, attachments, clips, medical grade adhesives or osseo-integrated implants.15,16,17,18 The advantages of using magnets to retain a prosthesis are that this is a non-invasive technique, which is cost effective and results in a prosthesis that is easy to clean and comfortable to use.19 However, for adequate retention, the facial prosthesis should be light in weight and the use of strong magnets will be required.19 This case report presents the rehabilitation of a patient with a mid-facial defect with a magnet-retained combined intra-oral–extra-oral prosthesis.
Case report
An 80-year-old male patient was referred to the restorative department to explore rehabilitation options for his mid-facial defect. The patient's main complaint was the passage of food to the nose while eating, and aesthetic concerns that resulted from wearing a dressing over his nasal defect. The patient reported that he had worn an obturator prosthesis for many years, but this was no longer functional owing to a combination of osteoradionecrosis (ORN) progression and tissue breakdown related to disrupted blood supply from previous surgery and radiotherapy treatment.
The patient's medical history included a diagnosis of desmoplastic melanoma of the nose and left cheek (BRAF, wild type; a type of melanoma where there is no known mutation present in the BRAF gene).20 This was treated with a wide local excision in 2012, followed by radiotherapy in 2013 (40 Gy in 10 fractions) and systemic treatment with pembrolizumab from 2016 to 2019. Following his treatment for head and neck cancer, the patient was subsequently diagnosed with postradiotherapy breakdown of the left cheek, and ORN of the left mandible and left maxilla. The patient's medical history also included hypertension, ischaemic heart disease, previous myocardial infarction, and type II diabetes mellitus, and he was prescribed cetirizine, clopidogrel, furosemide, ivabradine, oxycodone and pregabalin.
The patient was a regular dental attender who was registered at a general dental practitioner and was not dental phobic. The patient brushed twice daily with an electric toothbrush and removed his obturator at night. The patient's social history revealed that he was a non-smoker, rarely consumed alcohol and was retired.
Extra-oral examination revealed a unilateral partial nasal defect that extended onto the left cheek (Figures 1 and 2). Mouth opening was unrestricted. Intra-orally, there was a fistula in the sulcus adjacent to the upper left canine and upper left first premolar. The maxillary ridge was irregular. Areas of exposed bone were noted extending from the UL2 to UL7 region with the most notable areas of exposed bone in the UL3 region (2 x 2 mm) and in the UL5 region (7 x 2 x 5 mm). These areas were associated with mucosal breakdown and resulting soft tissue defects (Figures 3 and 4).
Figure 1. Extra-oral defect left nose/maxilla lateral view.Figure 2. Extra-oral defect left nose/maxilla anterior view.Figure 3. Intra-oral view of the maxillary arch.Figure 4. Intra-oral view of the mandibular arch.
The patient was partially dentate with more extensive tooth loss in the maxilla. Only the UR7 was present as a lone standing molar, and this tooth was heavily restored, had gross mesial caries and heavy calculus deposits. Caries was also noted on the LL1, LL2 and LL3. Generalized calculus was noted, and plaque control was deemed to be poor (Figures 3 and 4). The patient's current denture had poor retention and stability, which had worsened since the extraction of the UL6 a few months prior to the appointment.
Following consultation in the restorative department, the patient was diagnosed with caries UR7, LL1, LL2, LL3, plaque-induced gingivitis and ORN of the left maxilla.
An initial course of prevention and stabilization methods was completed. This involved oral hygiene instruction, diet advice, fluoride advice, non-surgical periodontal therapy and restoration of caries. The decision was taken to retain the UR7 despite the guarded prognosis owing to the high risk of ORN with an extraction.
The presence of ORN and the defects present on the ridge posed significant challenges with regards to treatment planning and rehabilitation. An implant-retained prosthesis was deemed unsuitable owing to the risk of further ORN. Consideration was given towards providing a new conventional obturator and facial prosthesis as separate prostheses, or using a combined approach. Through a multidisciplinary team approach and discussions with the patient, it was decided that the rehabilitation of the mid-facial defect with a magnet-retained prosthesis was the most suitable option for this patient.
Intra-and extra-oral prostheses were manufactured in a staged approach. To produce the intra-oral prosthesis, upper primary impressions were initially taken with a thermoplastic impression material (Impression compound, Kerr, Uxbridge) in a stock tray to capture the functional sulcus, and care was taken to keep the material away from the UR7. A muco-compressive material was selected to ensure that the tissues were displaced and the entire denture bearing area was recorded. A hydrocolloid impression with an alginate wash (Xantalgin, Kulzer, Germany) was completed to ensure that the UR7, peripheral extensions and at least 1 cm of height into the defect were captured.
For secondary impressions, a special tray was modified with a thermoplastic impression material (ISO Functional Sticks, GC, Belgium) to capture the defect and ensure that excess material did not extrude into the defect. This was followed by a peripheral impression that was taken using a thermoplastic impression material (ISO Functional Sticks, GC). Finally, alginate (Xantalgin, Kulzer) was used to record the remainder of the ridge and tooth-bearing area rather than a more rigid material owing to the compromised and mobile status of the UR7.
From the secondary impressions, models were poured and duplicated, and the master cast was modified as needed. A heat-cured acrylic baseplate was constructed that included a projection of acrylic extending into the nasal defect. The baseplate was reviewed clinically to assess for any areas of overextension. The peripheral seal was assessed by asking the patient to take sips of water. The extension of acrylic projection into nasal defect was reviewed to ensure there was no trauma to the nasal epithelium and that there was sufficient room and access for positioning a magnet (Figure 5).
Figure 5. Extra oral view of facial defect with obturator in situ prior to adding the magnet. Note the extension of the acrylic projection into the nasal defect.
Occlusal registration and wax-try in stages were then completed using standard prosthodontic techniques. The position of the paired magnet component (MPMS multi-purpose magnet, Technovent, UK) was considered, ensuring that there was sufficient access for the corresponding component in the subsequent facial prosthesis. The magnet was secured into the acrylic projection using cold cure acrylic (Figure 6). The intra-oral prosthesis was completed and the processes for manufacturing the nasal prosthesis were subsequently commenced (Figure 7).
Figure 6. Obturator with magnet on acrylic projection.Figure 7. Intra-oral view with obturator in situ.
Prior to the facial impression, the corresponding component of the paired magnet was placed on the obturator. The airway was protected with paraffin gauze dressing material (Jelonet, Smith & Nephew, UK). A pick-up impression was taken using medium-bodied silicone material (Affinis, Coltène, Switzerland) to record the location of the magnet and capture the extent of the facial defect.
To create a working model, the corresponding magnet was connected to the pick-up impression to recreate the position of the magnet in the intra-oral prosthesis. The impression was cast, and the model trimmed, which resulted in a working model that had the magnet in the correct position. An acrylic retentive component was manufactured to house the facial prosthesis magnet. A wax pattern of the facial prosthesis was produced in the lab, using standard maxillofacial prosthetic sculpting techniques.
The wax pattern was trialled on the patient, and the model was adjusted to ensure sufficient marginal adaption to the soft tissues. The colour of the prosthesis was determined by using different colour swatches to create a colour map. In the lab, gold primer was painted onto the acrylic retentive component to achieve a chemical bond. The try-in was then flasked and the silicone (M-511 silicone, Technovent) packed using the colour map to guide correct placement of the silicone. This was then placed into a clamp and put into boiling water for 90 minutes, where it was then de-flasked. Subsequent visits were for the addition of further extrinsic colour and to fit the facial prosthesis (Figures 8 and 9).
Figure 8. Obturator and facial prosthesis connected.Figure 9. Extra-oral view when obturator and facial prosthesis were in situ.
Rehabilitation of a mid-facial defect is complex, but this case posed additional restorative challenges owing to the progressive nature of the defect to be restored, and the contraindication of implants owing to ORN. The intra-oral appliance that was produced ensured that the intra-oral defect was obturated and therefore, the patient experienced less leakage of fluids and improved speech. The external facial prosthesis significantly improved the patient's appearance (Figure 9). Through the connection of these two components with a magnet, additional retention was gained, and the patient was able to wear the prosthesis without the need for adhesive (Figure 8). The negation of adhesive was welcomed by both the patient and clinician, as a reduced long-term survival of the facial prosthesis is well reported with its use in the literature.21 However, as the facial prosthesis and obturator are connected, the patient reported some movement from the facial prosthesis when eating. Overall, the patient saw significant improvements in eating, speech and facial aesthetics. From a clinical standpoint, satisfactory rehabilitation of a mid-facial defect with a magnet-retained combined intra-oral–extra-oral prosthesis was achieved.
Discussion
A common consequence of a mid-facial defect is a communication between the nasal and oral cavity, which can create problems with eating, speech, nasal regurgitation, aesthetics and psychological health.6 Where mid-facial defects are large or have unfavourable retentive features, adequate aesthetics and retention of prostheses can be difficult to achieve. The most reliable method to provide retention for such prostheses is via osseo-integrated implants because retention is not affected by defect anatomy and size, or environmental factors, such as sweating. However, cost, patient wishes, available bone and radiation may preclude this as a viable option.22,23
In the case presented, the primary resection was related to a desmoplastic melanoma to the infra-orbital nerve and the patient was therefore initially managed under the melanoma team rather than the head and neck team. The melanoma team completed an extensive resection, partial rhinectomy and forehead flap, so dental implants were not indicated at this stage. In cases where radiotherapy treatment is planned and implant placement/extractions are required, effort should be made to complete surgical procedures at the same time as primary resection to maximize the healing and minimize the number of surgical procedures the patient will need.24 Owing to progression of the disease, the patient developed a multifocal recurrence involving the maxilla and sinuses, which was treated non-surgically with radiotherapy. The patient then developed a fistula to the left cheek extending onto the left nasal reconstruction and oral cavity. At this stage the patient was referred to the restorative department, but unfortunately was no longer deemed a suitable candidate for implant placement owing to the history of ORN related to a previous irradiation dose of 40 Gy in 10 fractions to the anterior maxilla and the left zygomatic buttress. It was therefore decided that the use of a magnet retained intra-and extra-oral prosthesis was the most suitable option for this patient
The introduction of magnets composed of samarium cobalt and neodymium-ferro-boron alloys into the market has allowed the production of magnets that are much smaller than previously available. Furthermore, by coating such magnets in titanium, gold and nickel, problems caused by corrosion and tarnish are diminished, and mutual retention of an intra-and extra-oral prosthesis is possible with modern technology.25 An inert magnetic field is created by such magnets, which is harmless to humans and for those with cardiac pacemakers. In this case, a significant and positive psychological impact was seen as the magnets offered the patient a sense of reassurance. However, a gradual reduction in retention has been described in the literature once corrosion of the magnets commences and therefore, it is advised that magnets should be replaced once there is any sign of corrosion.6 Although magnet-retained facial prostheses are a safe and effective option to improve retention, continued maintenance of such prostheses is required.
A common issue with two-piece prostheses is that functional movements can cause the intra-oral prosthesis to mobilize, and consequently the facial prosthesis can also mobilize owing to its direct contact. This problem can be improved by maximizing the support, retention and stability of the intra-oral appliance and using extra-oral prostheses made of lightweight materials.26 Silicone is a lightweight material that also has excellent aesthetics and marginal adaptation, and is therefore a popular material used to create facial prostheses. However, the lack of mechanical and chemical bonding of this material with other materials is a limitation.14
This case report has presented the rehabilitation of a mid-facial defect with a two-piece magnet-retained facial prosthesis and obturator. Although a non-surgical conservative solution was adopted, the use of magnets significantly improved prosthesis retention, and marked improvements were seen with regards to speech, aesthetics, function and overall quality of life.
Conclusion
In conclusion, this case presents the successful rehabilitation of a patient with a combined intra-oral–extra-oral defect through the provision of a magnet-retained intra-and extra-oral prosthesis. Retention was improved by placing opposing magnets on the extra-oral facial prosthesis and intra-oral obturator, and the patient reported significant improvements with speech, deglutition and appearance. This case highlights the importance of a thorough medical history and clinical assessment to highlight all the relevant factors that will influence the treatment planning process. It also illustrates how patient engagement and effective multidisciplinary teamwork between the restorative dentists, dental technicians and maxillofacial prosthetists can achieve a satisfactory restorative solution for managing a combined mid-facial defect without surgical intervention.
