Prosthodontic management of edentulous patient with limited oral access using
implant-supported prostheses: A clinical report
Ansgar C. Cheng, BDS, MS,a Loh Kwok-Seng, MBBS,b Alvin G. Wee, BDS, MS, MPH,c and
Neo Tee-Khin, BDS, MSd
National University of Singapore, Singapore; College of Dentistry, Ohio State University,
Columbus, Ohio
Limited oral access presents a unique challenge to prosthodontic treatment. An edentulous patient who
developed microstomia after a maxillary lip resection is presented. The clinical procedure and the rationale
for the treatment approach using implanted-supported overdentures are discussed. (J Prosthet Dent
2006;96:1-6.)
A
limitation in mobility of the mandible that results
from tonic contracture of the masticatory muscles is
known as mandibular trismus.1 Patients with this condition may experience a significant limitation of jaw opening and overall jaw immobility. A limited oral opening
can be caused by head and neck radiation,2-6 surgically
treated head and neck tumors,6 reconstructive lip surgeries,7 reflex spasm,8 connective tissue disease,9,10
fibrosis of masticatory muscles,11 facial burns,12 and
microinvasion of the muscles of mastication.8,13
When a lip defect is reconstructed, the continuity of
the oral aperture is restored. However, because the net
loss of soft tissue from the resected lip is not replenished
in such a procedure, microstomia is inevitable. This clinical condition introduces significant challenges for regular food intake and regular oral hygiene maintenance. In
addition, having a limited oral opening can be a problem
for patients who require dental treatment.14,15 The use
of standard complete-arch stock impression trays may
be impossible, and this may preclude successful dental
prosthesis fabrication and prosthesis use. Management
of the problems associated with providing dental prostheses for patients with microstomia has not been well
reported,15 although the management techniques previously described include surgery8,16 and modification of
denture designs.15,17,18
The fabrication of a removable partial denture requires
an accurate impression of the denture-bearing area and a
record of appropriate anatomic landmarks.19,20 Detailed
preliminary impressions and accurate diagnostic casts are
crucial for surveys, denture design, development of custom trays, and definitive impressions. Conventionally,
a
Adjunct Associate Professor, Graduate Prosthodontics, National
University of Singapore.
b
Assistant Professor, Otolaryngology, Faculty of Medicine, National
University of Singapore.
c
Associate Professor, Section of Restorative Dentistry, Prosthodontics
and Endodontics, College of Dentistry, Ohio State University.
d
Adjunct Assistant Professor, Restorative Dentistry, National University of Singapore.
JULY 2006
stock trays are used to make preliminary impressions.
Even though stock impression trays come in various designs, sizes, shapes, and materials, the insertion of stock
trays may be impossible if there is a severe limitation in
the oral opening. Modification of a stock impression
tray may further reduce its size and ease its insertion
into the oral cavity. Clinically, an impression can be
made as long as the maximum vertical opening provides
an interarch space that is greater than the vertical height
of an impression tray, and the oral opening can be
stretched to a width that is equal to or greater than the
width of an impression tray. For most patients, successful
removal and insertion of impressions requires a reasonable degree of flexibility of facial and lip soft tissues. In situations in which scar tissue formation has decreased the
flexibility of the lips, insertion and removal of stock
impression trays may not be possible.
Border molding materials such as modeling plastic
impression compound,20,21 vinyl polysiloxane,22,23 and
polyether24-26 impression materials are used in removable prosthodontics. Polymeric border molding materials have several advantages over modeling plastic
impression compound. Polymeric border molding materials allow: (1) elimination of the need for multiple
insertions and removal to border mold the impression
tray, (2) ease of manipulation, (3) elimination of the
water bath, and (4) superior accuracy.27
The treatment of the edentulous mandible using an
endosseous implant-supported overdenture is a relatively simple, predictable, and widely accepted treatment
option.28-31 It has been shown that implant-supported
overdentures improve psychological well-being32 and
quality of life.33 The implant-supported overdenture
prosthesis offers easy access for oral hygiene maintenance and the provision of a denture flange to augment
missing dental alveolus.34
Overdenture prostheses require a certain amount of
space for adequate denture base thickness and housing
the prosthetic components. Preprosthetic assessment
of the available interocclusal distance is crucial for
the development of the definitive prosthesis. Patients
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CHENG ET AL
Fig. 1. Frontal view of reconstructed maxillary lip defect.
Fig. 2. Frontal view of opened oral cavity, with regular dental
mirror (diameter of 22 mm) for comparison. Estimated diameter of oral opening was less than 28 mm.
with minimally resorbed edentulous alveolar ridges may
have insufficient space for an implant-supported overdenture.35 Limited interarch space may also limit the
choice of prosthetic components. Surgical reduction of
the alveolar bone and the use of internal connection implants may overcome the space limitation.36
The purpose of this article is to describe the clinical
management of a patient with reduced perimeter of
the oral cavity and severe trismus using implant-supported removable prostheses. The implant-supported
denture prostheses restored mastication, speech, dental
articulation, anterior oral seal, and lip support.
with limited bone width for implant placement except
at the premolar areas. There was remarkable limitation
in the oral opening and reduced tissue flexibility. The
diameter of the oral opening was estimated to be less
than 28 mm. Making an impression of the maxillary
and mandibular alveolus using stock impression trays
was impossible due to limited oral access and reduced
lip flexibility. An additional surgical procedure was not
planned to improve the oral opening. Endosseous implant tissue-bar retained overdentures with modified
prosthodontic procedures were planned. Four endosseous implants were planned for the maxilla and 2
implants were planned for the mandible.
Due to the limited oral access, placement of dental implants was performed without using a surgical
template. Four endosseous implants with internal
connection (Certain; 3i Implant Innovations Inc, Palm
Beach Gardens, Fla) were placed in the maxillary premolar areas. Two endosseous implants (Certain; 3i Implants Innovations Inc) were placed in the mandibular
canine regions (Fig. 3). No prosthesis was used during
the healing period. The postoperative healing was
uneventful.
The implants were exposed approximately 8 months
after implant placement. The anterior implants bilaterally in the maxilla failed. The 2 osseointegrated maxillary
implants were determined to be located too far posteriorly, and this rendered retentive component connection
difficult. They were left with 4-mm healing abutments
(3i Implant Innovations Inc) and served as conventional
overdenture abutments without any retentive element
to simplify the prosthodontic treatment procedures.
Putty-type impression material (Aquasil; Dentsply
Intl, York, Pa) was manually dispensed intraorally to
serve as custom trays for diagnostic maxillary and mandibular impressions. The impression putty was soft
during initial insertion. Once the impression putty
was placed intraorally, it was carefully positioned onto
CLINICAL REPORT
A 71-year-old Chinese woman was referred for prosthodontic assessment of an acquired maxillary defect. A
review of her medical history showed that she had type-2
diabetes. Her maxillary lip, columella, and nasal septum
were resected due to a necrotizing fascitis. The resulting maxillary lip defect was reconstructed using a
Karapandzic flap.37 The adjacent soft tissue from the
nasal-labial fold was rotated medially and inferiorly to
reconstruct the maxillary lip defect37 (Fig. 1).
The overall perimeter of the oral cavity was reduced
significantly. Visual inspection of her lateral facial profile
revealed that the mandibular arch was approximately 10
mm anterior to the maxillary arch (Fig. 2). The clinical examination revealed a completely edentulous oral
cavity with moderate alveolus resorption. Severe bony
resorption was noted in the anterior maxilla. The surgical procedure occurred approximately 5 months before
her prosthodontic evaluation. Postsurgically, the patient’s diabetic condition was under control with medication and dietary modifications. The patient was not
using any type of dental prosthesis.
A panoramic radiograph and computerized tomographic scan of the maxilla revealed type 4 bone,38
2
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CHENG ET AL
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Fig. 3. Panoramic radiographic view immediately after implant placement. At stage 2 surgery, 1 implant on each side
of maxilla failed to osseointegrate.
Fig. 4. Definitive maxillary (A) and mandibular (B) impressions made of vinyl polysiloxane material in acrylic resin
custom trays.
Fig. 5. Matrix components of attachments attached to heatpolymerized denture base using autopolymerized acrylic
resin.
the denture-bearing areas, and the impression material
was border molded to the appropriate contour. The impression putty custom tray was removed after polymerization. It was then inspected for accuracy, and
additional impression putty was added to the tray to establish the appropriate extension as needed. The vinyl
polysiloxane putty impression tray was removed, and
the excess bulk was trimmed off. Medium-viscosity impression material (Express; 3M ESPE, St Paul, Minn)
was added onto the silicone custom trays and inserted
intraorally. The diagnostic impressions were removed
after the impression material was fully polymerized and
visually inspected for accuracy.
The maxillary and mandibular diagnostic impressions
were poured using American Dental Association (ADA)
type V dental stone (Die-Keen; Heraeus Kulzer, Hanau,
Germany). Extension of the definitive impression custom trays was outlined on the diagnostic casts. Custom
JULY 2006
mandibular and maxillary impression trays were made
using autopolymerizing acrylic resin (Formatray; Kerr,
Orange, Calif). During the definitive impression appointment, the fit of the custom trays was verified.
Border molding was accomplished by applying impression putty (Aquasil; Dentsply Intl) onto the impression
tray border, which was then inserted and border molded.
Upon polymerization of the putty, the border-molded
impression trays were withdrawn and inspected for accuracy. Additional putty was added to any deficient areas.
Tray adhesive (Tray adhesive; Dentsply Intl) was applied
to the intaglio surface and borders of the impression
trays. A wash impression was made using medium-viscosity vinyl polysiloxane (Express; 3M ESPE) (Fig. 4).
Final casts were poured in ADA type V dental stone
(Die-Keen; Heraeus Kulzer). A wax pattern of the definitive denture bases was made on the final casts, and the
denture bases were made using heat-polymerized acrylic
resin (Lucitone 199; Dentsply Intl). Low-profile resilient attachments (Locator; Zest Anchors, Escondido,
Calif) were selected. The matrix/patrix abutment
portions of the attachment were connected to the
implants. The attachment matrices were intraorally
attached to the heat-polymerized denture base using
3
THE JOURNAL OF PROSTHETIC DENTISTRY
CHENG ET AL
Fig. 7. Completed wax arrangement of artificial teeth. Note
class 3 incisal relationship.
Fig. 6. Intaglio surface of maxillary (A) and mandibular (B)
denture base. Black processing analogs of matrix attachments
were eventually replaced during prosthesis insertion.
autopolymerized acrylic resin (Quick-resin; Shofu,
Japan) (Figs. 5 and 6).
A centric relation record was obtained with the
definitive bases and wax occlusion rims (NeoWax;
Dentsply Intl) using an interocclusal registration material (Regisil; Dentsply Intl). The occlusal vertical dimension was recorded at a reduced dimension to ensure
sufficient interocclusal space to ease food bolus manipulation. The casts were mounted in a semiadjustable articulator with a facebow record (Hanau Wide-vue;
Teledyne Waterpik, Fort Collins, Colo) and the centric
relation record. Zero-degree artificial teeth (Dentacryl
SA; Dentsply Intl) were arranged (Fig. 7). The denture
teeth were processed on the definitive denture bases using
heat-polymerized acrylic resin (Lucitone 199; Dentsply
Intl). At the insertion appointment, denture base adjustments were performed with a pressure indicating paste
(Pressure Indicating Paste; Mizzy Inc, Cherry Hill, NJ).
The patient was instructed in the insertion and removal
of the prostheses (Fig. 8). Daily oral hygiene instruction
was reinforced. After the initial period of postinsertion adjustment, follow-up appointments were scheduled every 6
months.
4
Fig. 8. Definitive prostheses.
DISCUSSION
The selection of the lip reconstruction option is based
on the size, depth, and location of the defect. Full-thickness defects that are less than half the surface area of the
lip are usually closed primarily.37 Defects that span between half and two thirds of the surface area of either
lip are commonly closed by means of the 2-stage
Abbe-Estlander flap technique.37 This technique results
in lip-switching flaps, which commonly lead to progressive microstomia because of the loss of neural stimulation.
The Karapandzic flap technique involves the creation
of circumoral incisions in the nasolabial folds. The incisions are made close to the intraoral mucosa. The orbicularis oris muscle is freed from the other perioral
muscles to enhance advancement of the flap. Immediate
function may be restored because the neurovascular
pedicle is preserved.
In the situation presented, the reconstructed maxillary lip had altered the neutral zone of the maxillary
arch significantly. Maxillomandibular relation records
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CHENG ET AL
and mounting of the casts in the articulator revealed a
class 3 skeletal pattern. Due to the skeletal pattern,
zero-degree denture teeth were chosen for the development of the occlusion. The development of the maxillary
lip support was performed to minimize violation of the
neutral zone.
In the treatment described, a semi-rigid material was
used as an impression tray for the diagnostic impressions. Vinyl polysiloxane was used because of its rigidity
and the ease of dispensing and mixing it. Because the
material was hand-dispensed intraorally, the difficulties
of stock impression tray insertion for a patient with
microstomia were eliminated. This material offers a reasonable amount of elasticity and can be removed even
though it may be slightly oversized with respect to the
limited oral access.
Surgical templates are helpful in accurate placement
of endosseous implants. However, use of a surgical template requires unhindered oral access. Surgical templates
were not used for this patient due to limited oral opening. Placement of implants in the mandibular anterior
area was predictable due to relatively better visual and
manual access. Surgical bony augmentation in the maxilla, such as a sinus-lift procedure, was not performed
due to limited access. As a result, placement of implants
in the maxilla was limited to the maxillary premolar areas
due to limitation in bone volume in the anterior maxilla
and compromised surgical access.
A history of diabetes and a type-4 bone bed are considered potential risk factors in endosseous implant success. As long as the diabetic condition is under control,
studies have shown promising results in diabetic patients
with implant-supported removable overdentures.39,40
In this report, the maxillary bone bed of the patient
was diagnosed as type-4 bone. Two out of the 4 implants
placed in the maxilla failed to integrate, which resulted
in a success rate of only 50% in the maxilla. If all 4
implants placed were osseointegrated with a favorable
antero-posterior spread, a retentive bar could be constructed for prosthesis retention. Even though no retentive element was connected to the maxillary implants
due to limited oral access, the implants served as conventional overdenture abutments to provide additional
denture support and assist in maintaining bone level
and reduce alveolar resorption. In the anterior mandible, both implants integrated without complications.
They were crucial in providing retention for the mandibular complete overdenture prosthesis. Two overdenture
attachments were selected due to their ease of manipulation and small size.
Definitive impressions of the maxilla and mandible
were made without placement of any implant impression
coping on the osseointegrated implants. This facilitated
impression making in an oral cavity with limited access.
A heat-polymerized permanent denture base was used
for the remainder of the clinical procedures, and the
JULY 2006
THE JOURNAL OF PROSTHETIC DENTISTRY
mandibular attachments were attached to the definitive
denture base using autopolymerized acrylic resin. These
procedures facilitated the manipulation of the denture
prostheses under fabrication.
SUMMARY
Severe limitation in the oral opening is a rare clinical presentation. Gaining access to the oral cavity for
such patients is difficult for any prosthodontic procedure. This article described the fabrication of implantsupported complete overdentures for a patient with a
severely limited oral opening.
REFERENCES
1. The glossary of prosthodontic terms. J Prosthet Dent 2005;94:10-92.
2. Dreizen S. Oral complications of cancer therapies. Description and incidence of oral complications. NCI Monogr 1990:11-5.
3. Engelmeier RL, King GE. Complications of head and neck radiation therapy and their management. J Prosthet Dent 1983;49:514-22.
4. Brunello DL, Mandikos MN. The use of a dynamic opening device in the
treatment of radiation induced trismus. Aust Prosthodont J 1995;9:45-8.
5. Beumer J 3rd, Curtis T, Harrison RE. Radiation therapy of the oral cavity:
sequelae and management, part 1. Head Neck Surg 1979;1:301-12.
6. Horst RW. Trismus: its causes, effects and treatment. ORL Head Neck
Nurs 1994;12:11-2.
7. Smith PG, Muntz HR, Thawley SE. Local myocutaneous advancement
flaps. Alternatives to cross-lip and distant flaps in the reconstruction of
ablative lip defects. Arch Otolaryngol 1982;108:714-8.
8. Ichimura K, Tanaka T. Trismus in patients with malignant tumours in the
head and neck. J Laryngol Otol 1993;107:1017-20.
9. Conroy B, Reitzik M. Prosthetic restoration in microstomia. J Prosthet
Dent 1971;26:324-7.
10. al-Hadi LA. A simplified technique for prosthetic treatment of microstomia in a patient with scleroderma: a case report. Quintessence Int
1994;25:531-3.
11. Nakajima T, Sasakura H, Kato N. Screw-type mouth gag for prevention
and treatment of postoperative jaw limitation by fibrous tissue. J Oral
Surg 1980;38:46-50.
12. Maragakis GM, Garcia-Tempone M. Microstomia following facial burns.
J Clin Pediatr Dent 1998;23:69-74.
13. Cohen SG, Quinn PD. Facial trismus and myofascial pain associated with
infections and malignant disease. Report of five cases. Oral Surg Oral Med
Oral Pathol 1988;65:538-44.
14. Meraw SJ, Reeve CM. Dental considerations and treatment of the oncology patient receiving radiation therapy. J Am Dent Assoc 1998;129:201-5.
15. Heasman PA, Thomason JM, Robinson JG. The provision of prostheses for
patients with severe limitation in opening of the mouth. Br Dent J 1994;
176:171-4.
16. Werner R. Treatment of trismus following radiotherapy in nasopharyngeal
cancer (N.P.C.). Singapore Med J 1974;15:64-8.
17. Naylor WP, Manor RC. Fabrication of a flexible prosthesis for the edentulous scleroderma patient with microstomia. J Prosthet Dent 1983;50:
536-8.
18. Suzuki Y, Abe M, Hosoi T, Kurtz KS. Sectional collapsed denture for a partially edentulous patient with microstomia: a clinical report. J Prosthet
Dent 2000;84:256-9.
19. Halperin AR, Graser GN, Rogoff GS, Plekavich EJ. Mastering the art of
complete dentures. Chicago: Quintessence; 1988. p. 31-80.
20. Felton DA, Cooper LF, Scurria MS. Predictable impression procedures for
complete denture. Dent Clin North Am 1996;40:39-51.
21. Allen P, Worrollo S. Border molding with composition heated in a microwave oven. J Prosthet Dent 1991;65:325.
22. Colaizzi FA, Farah JW. Simplified border molding using silicone material.
Fla Dent J 1981;52:20-1.
23. Chaffee NR, Cooper LF, Felton DA. A technique for border molding edentulous impressions using vinyl polysiloxane material. J Prosthodont 1999;
8:129-34.
24. Davis DM. Developing an analogue/substitute for the maxillary denturebearing area. In: Zarb GA, Bolender CL, Eckert SE, Fenton AH, Jacob RF,
5
THE JOURNAL OF PROSTHETIC DENTISTRY
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
6
Meriscske-Stern R, editors. Prosthodontic treatment for edentulous
patients: complete dentures and implant-supported prostheses. 12th ed.
St Louis: Mosby; 2003. p. 211-31.
Tan HK, Hooper PM, Baergen CG. Variability in the shape of maxillary
vestibular impression recorded with modeling plastic and a polyether
impression material. Int J Prosthodont 1996;9:282-9.
Smith DE, Toolson LB, Bolender CL, Lord JL. One-step border molding of
complete denture impressions using a polyether impression material.
J Prosthet Dent 1979;41:347-51.
Groh CL, O’Brien WJ. Impression materials. In: O’Brien WJ, editor. Dental
materials properties and selection. Chicago: Quintessence; 1989. p. 177-202.
Feine JS, Carlsson GE, Awad MA, Chehade A, Duncan WJ, Gizani S, et al.
The McGill consensus statement on overdentures. Mandibular two-implant overdentures as first choice standard of care for edentulous patients.
Montreal, Quebec, May 24-25, 2002. Int J Oral Maxillofac Implants
2002;17:601-2.
Simon H, Yanase RT. Terminology for implant prostheses. Int J Oral Maxillofac Implants 2003;18:539-43.
Ekelund JA, Lindquist LW, Carlsson GE, Jemt T. Implant treatment in the
edentulous mandible: a prospective study on Branemark system implants
over more than 20 years. Int J Prosthodont 2003;16:602-8.
Gotfredsen K, Holm B. Implant-supported mandibular overdentures
retained with ball or bar attachments: a randomized prospective 5-year
study. Int J Prosthodont 2000;13:125-30.
Kent G, Johns R. Effects of osseointegrated implants on psychological and
social well-being: a comparison with replacement removable prostheses.
Int J Oral Maxillofac Implants 1994;9:103-6.
Wismeijer D, Vermeeren JI, van Waas MA. Patient satisfaction with overdentures supported by one-stage TPS implants. Int J Oral Maxillofac
Implants 1992;7:51-5.
Mericske-Stern R. Treatment outcomes with implant-supported overdentures: clinical considerations. J Prosthet Dent 1998;79:66-73.
CHENG ET AL
35. Pasciuta M, Grossman Y, Finger IM. A prosthetic solution to restoring the
edentulous mandible with limited interarch space using an implanttissue-supported overdenture: a clinical report. J Prosthet Dent 2005;
93:116-20.
36. Phillips K, Wong KM. Space requirements for implant-retained bar-andclip overdentures. Compend Contin Educ Dent 2001;22:516-8, 520, 522.
37. Karapandzic M. Reconstruction of lip defects by local arterial flaps. Br J
Plast Surg 1974;27:93-7.
38. Lekholm U, Zarb GA. Patient selection and preparation. In:
Branemark PI, Zarb GA, Albrektsson T, editors. Tissue-integrated prostheses: osseointegration in clinical dentistry. Chicago: Quintessence; 1985.
p. 199-209.
39. Moy PK, Medine D, Shetty V, Aghaloo TL. Dental implant failure rates
and associated risk factors. Int J Oral Maxillofac Implants 2005;20:
569-77.
40. Morris HF, Ochi S, Winkler S. Implant survival in patients with type 2
diabetes: placement to 36 months. Ann Periodontol 2000;5:157-65.
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3 MOUNT ELIZABETH, #08-10
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Copyright Ó 2006 by The Editorial Council of The Journal of Prosthetic
Dentistry.
doi:10.1016/j.prosdent.2006.04.010
VOLUME 96 NUMBER 1