implant-retained skull prosthesis to cover a large defect of the … · implant-retained skull...
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CLINICAL REPORT
aDentist, DepbProfessor anthe NetherlancProfessor anthe NetherlandAssistant PrGroningen, th
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Implant-retained skull prosthesis to cover a large defect of thehairy skull resulting from treatment of a basal cell carcinoma:
A clinical report
Jitske Hoekstra, DDS,a Arjan Vissink, MD, DDS, PhD,b Gerry M. Raghoebar, MD, DDS, PhD,c andAnita Visser, DDS, PhDd
ABSTRACTSkin carcinoma, particularly basal cell carcinoma, and its treatment can result in large defects of thehairy skull. A 53-year-old man is described who was surgically treated for a large basal cell carci-noma invading the skin and underlying tissue at the top of the hairy skull. Treatment consisted ofresecting the tumor and external part of the skull bone. To protect the brain and to cover the defectof the hairy skull, an acrylic resin skull prosthesis with hair was designed to mask the defect. Theskull prosthesis was retained on 8 extraoral implants placed at the margins of the defect in the skullbone. The patient was satisfied with the treatment outcome. (J Prosthet Dent 2017;117:690-693)
Basal cell carcinoma (BCC) isthe most common form of skincancer1,2 and is mostly foundon the face and/or head.1,2
BCCs rarely metastasize, butwhen left untreated, they caninvade facial and skull bones,and even the sinuses andbrain.1 Incomplete removal of
a BCC should be considered an indicator of local recur-rence.2 Therefore, large invading BCCs are often treatedsurgically with a wide surgical excision. Such resectionsusually result in defects needing reconstruction, espe-cially with skull bone resections. Commonly, these de-fects are treated with free grafts or myocutaneous skinflaps. Although the defect can be adequately covered bysuch approaches, the esthetic outcome is often poor, andthe impact on the patient’s quality of life is large.3,4An alternative is the fabrication of an acrylic resinprosthesis with hair. However, although such a pros-thesis has favorable esthetics and protects the brain, theretention of such a large, thick, and heavy acrylicresin prosthesis is difficult. Extraoral implants mighthelp retain such prostheses and have been previouslyused to retain wigs in the case of large hair defects.5
The purpose of this clinical report was to describethe fabrication of an implant-retained acrylic skull
artment of Oral and Maxillofacial Surgery, University of Groningen, Univerd Oral and Maxillofacial Surgeon, Department of Oral and Maxillofacial Suds.d Oral and Maxillofacial Surgeon, Department of Oral and Maxillofacial Suds.ofessor, Maxillofacial Prosthodontist, Department of Oral and Maxillofaciale Netherlands.
prosthesis with hair and the treatment outcome for apatient with a large skull defect after the resection of aBCC.
CLINICAL REPORT
A 53-year-old man was diagnosed with a large BCC ontop of his skull that had infiltrated the skin and under-lying tissue (Fig. 1). The BCC and the outer cortex andmedullary space of the calvarial bone was surgicallyremoved. To support a future skull prosthesis, 8 extraoralimplants (titanium screw implants, 4.0 mm diameter, 4mm length, with an external flange; Entific MedicalSystems) were placed in the skull bone at the margins ofthe defect. The implants were equally spaced around thedefect (Fig. 2). The exposed bone was covered with a freeskin graft from the upper leg. After an osseointegrationperiod of 3 months, the implants were uncovered under
sity Medical Center Groningen, Groningen, the Netherlands.rgery, University of Groningen, University Medical Center Groningen, Groningen,
rgery, University of Groningen, University Medical Center Groningen, Groningen,
Surgery, University of Groningen, University Medical Center Groningen,
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Figure 1. A, Large basal cell carcinoma (BCC) on top of skull. B, Magnetic resonance image showing spreading of BCC (margins indicated with arrows)and infiltration of BCC into bone (arrowheads).
Figure 2. Defect of skull resulting from removal of basal cell carcinomacovered by skin graft. Impression posts diverge as implants placedperpendicular to skull bone.
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local anesthesia. The skin was thinned and healingabutments were placed.6
Two weeks after the implants were uncovered, theprosthetic treatment started. The first step was to makean alginate impression (Hydrogum; Zhermac Clinical) ofthe defect with the healing abutments in situ. The algi-nate was reinforced with fast set plaster material (SnowWhite Plaster No. 2; Kerr Dental) on top of the alginate.The alginate impression was poured in plaster, and thecast was used to fabricate an individual impression tray(close fit) with holes at the location of the implants. Nextthe healing abutments were removed, and the impres-sion tray was placed and the impression copings wereplaced on the implants through the holes in the tray. Thisorder was used as the implants were placed perpendic-ular to the bone for maximum contact of the flange of the
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implants with the skull bone. Thus, the implants divergedfrom each other, making it impossible to first place theimpression copings and then the impression tray as iscommonly done with impressions for implant-supportedprosthodontics (Fig. 2).
After placing the impression copings, the impressiontray was lifted slightly, allowing the polyether impressionmaterial (Impregum; 3M ESPE) underneath the impres-sion tray and around the impression copings to be ejec-ted, and the impression tray was seated. From thisdefinitive impression, the second plaster cast was pro-duced, on which a preliminary light polymerizing acrylicresin shield (Triad custom tray material (original blue);Dentsply Sirona) was fabricated with magnet retentionplaced at the location of the implants (Fig. 3A). Thehealing abutments were replaced by magnet abutments(Steco Magnet Abutments; Technovent Ltd) before theacrylic resin shield was placed. For additional retentionon the most ventral implant, a stud abutment (Locator;Nobel Biocare) was placed.
The preliminary acrylic resin shield was adjustedbefore a definitive acrylic resin shield with magnets and astud abutment at the most ventral spot was made. At therequest of the hair specialist, the acrylic resin shield wasmade slightly convex and perforated for ventilation of theskin. The definitive shield was converted into an implant-retained skull prostheses by placing the hairpiece on topof the shield. The hairpiece was attached with tape(Scotchmate Velcro; 3M) on top of the prosthesis to allowfor easy replacement; a hairpiece usually has a shorter lifethan an acrylic resin shield (Fig. 3).
The patient was instructed how to clean the implantsand prosthesis. He was recalled 4 times a year to evaluatethe cleanliness of the implants and the health of the peri-implant tissue. Such a frequent recall schedule was needed
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Figure 3. Definitive skull prosthesis with artificial hair. A, Acrylic resin shield in place not yet covered by hairpiece. B, Defect of skull with magnetsin place. C, Hairpiece attached with Velcro tape to acrylic resin shield. D, Skull prosthesis with hair in place to cover defect.
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because the patient found it difficult to clean the implantsat the back of the skull. The skin and muscle layer sur-rounding the implants was rather thick but did not result insigns of peri-implant inflammation and/or bone loss.
During the 2-year follow-up period, the peri-implantskin health was evaluated every 3 months. Some rednessof the peri-implant skin was observed. The hairpiece hadto be renewed every 6 months. The patient was satisfiedwith the outcome of the prosthetic treatment.
DISCUSSION
This clinical report describes a patient with a large BCCon top of his skull resulting in a large defect of the cal-varial bone after resecting the BCC. Thus, rehabilitationwas needed to protect the brain and for esthetics. Thecraniofacial defect was rehabilitated with an acrylic resinimplant-retained skull prosthesis with hair. To ourknowledge, no similar treatments have been describedother than 2 patients whose wigs were retained withextraoral implants to cover large hair defects.5 In thesepatients, the skull bone was intact, and implants could beplaced in optimal central locations. One patient whose
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similar large BCC on top of his skull was treated surgi-cally was described, but the clinical report only describedthe surgery treatment and histology reports.7 Neitherarticle described detailed prosthetic treatment.
A stud abutment was used at the most frontal implantfor extra retention and easier positioning of the pros-thesis. Instead of using this attachment, magnets withhigh retentive forces (up to 11.5 to 13.0 N) could havebeen used. However, these abutments are expensive, sothe stud attachment was selected.
Although the treatment outcome was satisfactory, anumber of problems were encountered. The skin aroundthe implants was rather thick, especially at the back ofthe head. Ideally, implants that perforate the skin shouldbe surrounded by a thin layer of peri-implant tissue soskin is accompanied by fewer peri-implant problems.8
However, some redness of the peri-implant skin wasobserved in this patient. Another problem encounteredwas the angulation of the implants, as all implants had tobe placed perpendicular to the skull bone. Thus, the or-der of the impression procedure had to be modified asdescribed. Instead of using screw-retained impressioncopings, specifically designed impression transfer
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magnets could have been used. By using the screw-retained copings, an impression at the implant, ratherthan the abutment level, was possible. An impressionwith digital scanning might also have solved the diffi-culties with the impression making, but it is ratherdifficult to scan large defects with intraoral scanners.
CONCLUSIONS
An implant-retained acrylic resin skull prosthesis withhair is a good option for patients with large defects of thehairy skull, as it protects the brain and provides favorableesthetics.
REFERENCES
1. Beumer J, Marunick MT, Esposito SJ. Maxillofacial rehabilitation, prosthodonticand surgical management of cancer-related, acquired, and congenital defects ofthe head and neck. Chicago: Quintessence Publishing Co Inc; 2011. p. 257-8.
2. Gualdi G, Monari P, Crotti S, Damiani G, Facchetti F, Calzavara-Pinton P,et al. Matter of margins. J Eur Acad Dermatol Venereol 2015;29:255-61.
3. Rathod S, Livergant J, Klein J, Witterick I, Ringash J. A systematic review ofquality of life in head and neck cancer treated with surgery with or withoutadjuvant treatment. Oral Oncol 2015;51:888-900.
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4. Schoen PJ, Raghoebar GM, van Oort RP, Reintsema H, van der Laan BF,Burlage FR, et al. Treatment outcome of bone-anchored craniofacial pros-theses after tumor surgery. Cancer 2001;92:3045-50.
5. Weischer T, Mohr C. A new application for craniofacial implants: wigs. Int JProsthodont 2000;13:108-11.
6. Raghoebar GM, Van Oort RP, Roodenburg JLN, Reintsema H, Dikkers FG.Fixation of auricular prostheses by osseointegrated implants. J Invest Surg1994;7:283-90.
7. Pirici I, M�arg�aritescu O, Cernea D, Stoica LE, Sarl�a CG, Pirici D. Fronto-parietal pial extension of a basal cell carcinoma of the scalp-case report. Rom JMorphol Embryol 2014;55:675-81.
8. Visser A, Raghoebar GM, van Oort RP, Vissink A. Fate of implant-retainedcraniofacial prostheses: Life span and aftercare. Int J Oral Maxillofac Implants2008;23:89-98.
Corresponding author:Dr Anita VisserDepartment of Oral and Maxillofacial SurgeryUniversity Medical Center GroningenPO Box 30.001NL-9700 RB GroningenTHE NETHERLANDSEmail: [email protected]
AcknowledgmentsThe authors thank dental technicians Anne Wietsma and Ashwin Beekes for theirtechnical support; Dr W. Noorda (maxillofacial prosthetist) for the clinical images;and J. Brouwer (Ornatrix, Marum, The Netherlands) for making the hairpieces.
Copyright © 2016 by the Editorial Council for The Journal of Prosthetic Dentistry.
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