Dental Tribune Africa Sub-Saharan Edition No. 1, 2017

04 CLINICAL Dental Tribune African Sub-Saharan Edition | 1/2017 Mechanically-retained facial prosthesis for a large defect following Cancrum Oris: a clinical report By Avish J. Jagathpal,1 Ashana Harryparsad,2 Rajesh Doolabh3 and Benjamin F. Calitz4 required Abstract Retention is of critical importance in the satisfactory performance of a large maxillofacial prosthesis. Large defects often lack sufficient undercut to allow prostheses to be self-retentive. External modifications of the prosthesis are often required to provide an acceptable result. Clinical history: A 10-year-old male presented with a large facial defect and gross scarring following radical ablative surgery in treatment of cancrum oris. The intention of treatment was to restore esthetics to the patient using a removable facial prosthesis until the patient is old enough to receive an implant retained prosthesis. Methods: Due to the patient's age and nature of the defect, the prospective size and weight of the prosthesis the use of mechanical retention that could not be achieved with conventional retentive methodology. An acrylic framework was manufactured as a substructure for the silicon prosthesis. Elastic-retained spectacles were luted via a custom screw-retained chrome-cobalt nose pad. To stabilize the inferior border of the prosthesis, a clear soft thermoplastic polyurethane brassiere strap was threaded through the chin cup and connected to the spectacle strap. This provided the prosthesis with adequate resistance to vertical displacement. Conclusion: The patient’s appearance was early psychosocial rehabilitation reintegration until a more rigid, implant based prosthesis becomes a viable treatment option. Rapid facial growth is expected over the years to follow and regular maintenance visits will be required. enhanced, enabling and and Introduction Trauma, congenital malformation, and ablative surgery may result in large facial defects that cannot be surgically restored. Such defects lead to aesthetic, functional, phonetic insufficiencies.1 These are associated with severe psychological strain, often giving rise to alteration in a patient’s self-esteem, stability, personality, and social interaction.2 A facial prosthesis, whether provisional or definitive, therefore enables an environment that is conducive to better function, aesthetics and social reintegration.3 emotional 1 BDS, PDD, Graduate student, Department of Prosthodontics, School of Dentistry, University of Pretoria, Pretoria, South Africa 2 Consultant, Department of Prosthodontics, School of Dentistry, University of Pretoria, Pretoria, South Africa 3 Graduate student, Department of Prosthodontics, School of Dentistry, University of Pretoria, Pretoria, South Africa 4 BTech, Dental technician, DuraArt Dental Laboratory, Pretoria, South Africa 1 4 2 3 5 Figure 1: Frontal profile photo of the patient 2 years following treatment of cancrum oris. Note severe facial scarring and the union of external and internal facial structures. Figure 2: Left profile photo depicting severe loss of facial prominence due to loss of the nasal cartilage, premaxilla, anterior mandible and associated labial tissue. Figure 3: Right profile of the patient. Figure 4: Fabrication of an impression-dam to retain the flowable alginate impression material. Note the high-volume evacuator tip retained between the patient’s tongue and residual hard palate to act as a breathing apparatus during the impression taking procedure. The nasal aperture has been blocked out with cotton wool. Figure 5: Wax try-in of the sculpted prosthesis. the Rehabilitation of such defects however, presents a unique challenge for restoring maxillofacial prosthodontist. The typical result is that the inferior base of a prospective prosthesis typically rests on movable tissue.4 When coupled with the lack of sufficient undercut, the inevitable consequence is the inability of the self-retentive.5 prosthesis Retention is of critical importance in the satisfactory performance of a maxillofacial prosthesis. It aids to enhance aesthetics, comfort, function, adaptation, and the concealing of the prosthesis. Extrinsic retention is typically attained via secondary mechanical factors, skin adhesives and implants (magnets, ball or bar attachments).6 to be The use of adhesives in large facial defects is limited as it may irritate the supporting tissues, may not withstand the prosthesis weight, and causes deliquescence of the adhesive material when exposed to moisture. to Modifications overcome difficulties are often required to provide an acceptable result. This requires innovative methodology as outlined in this article and be extrapolated to treatment of patients techniques certain that can with similar defects. Clinical assessment Clinical report A 10-year-old male was referred to the post-graduate prosthodontic clinic of the University of Pretoria Oral and Dental Hospital, South Africa, for prosthetic and management. The patient presented with a large facial defect and gross scarring following radical ablative surgery 2 years prior, for the treatment of Cancrum Oris (Noma) (Fig. 1, 2 and 3). radiographic evaluations were carried out. Clinical examination revealed that extensive fibrosis was present as a consequence of the resection, resulting in a maximum mouth opening of 1mm. The exposed oral and nasal mucosa were dry and tender to palpation. Despite the gross extent of scarring, the phonetically functional, and was able to compress most foods against his palate using the tongue, as a form of mastication. patient was and A three-dimensional cone beam computerized tomographic evaluation (Planmeca, ProMax3D Max) of the patient revealed a resection of the pre- maxilla, ranging from tooth 13 to 24, and alveolectomy of the left anterior mandible. Developing tooth buds were present in the distal segments of both the maxilla and mandible. Limited retained secondary dentition was evident in the anterior segments. The treatment aim was to achieve closure of the defect, and attain concurrent re-establishment of an aesthetic profile. Attempts at retention of the prosthesis were expected to be challenging; due to the age of the patient, implant retained prostheses were contra-indicated. Furthermore, financial constraints and the expected weight of the prosthesis as a consequence of size precluded the use of dermal adhesives in aiding retention. As an alternative, eyeglass frames have historically proven helpful in providing mechanical retention and concealing prostheses. To improve mechanical stability of a large prosthesis, elastic strips are often placed around the back of the head to join both ends of the eyeglass frames.3 It was therefore decided to utilize a spectacle-aided retention method with reinforcing elastics to stabilize the superior and inferior aspects of the prosthesis onto the patient’s face. Treatment sequence The initial phases of the construction followed conventional maxillofacial impression protocols. The nasal cavity was packed with cotton wool and lined with petroleum jelly (Vaseline Jelly, Original) to prevent nasal aspiration of the primary impression material. The patient was taught to breathe through a high-volume evacuator tip (Dochem, Evacuator tips, 1A5151 vented “S” white) placed between his palate and tongue, and was further instructed to close his eyes and not make any facial movements during the impression taking procedure. A dam-technique was used to acquire a full facial impression; bands of periphery wax (Kemdent, white periphery wax) were linked together and adapted to the border of the intended impression. Pink modelling wax (Zeta, Tenawax) was moulded and attached to this periphery to form the dam walls. Bite registration material (Heraeus, Flexitime) was injected onto the periphery wax to create a seal against the patient’s skin and prevent the impression material from leaking beyond the dam as seen in figure 4. Regular set alginate (Dentsply, Blueprint 20+) was mixed to a high- flow consistency and poured into the dam, and reinforced with pieces of wooden tongue blades (Astra Med,

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