Prosthetic rehabilitation of a patient following maxillectomy with orbital exenteration

The maxillectomy patient despite the drastic nature of the procedure can often be restored to an acceptable aesthetic and functional condition. The treatment of maxillectomy patient presents an excellent opportunity for the surgeon and the prosthodontist to coordinate their efforts to enhance the patient's rehabilitation. This clinical report describes the prosthetic rehabilitation of a patient with squamous cell carcinoma of the right maxilla requiring maxillectomy with orbital exenteration.

Preshaped hydroxyapatite tricalcium-phosphate implant using three-dimensional computed tomography in the reconstruction of bone deformities of craniomaxillofacial region

We prepared solid life-sized models and templates of implants based on three-dimensional computed tomography data in six cases with a bone deformity of the craniomaxillofacial region. After simulation surgery using these models and templates, the preshaped hydroxyapatite-tricalcium phosphate (HAP-TCP) implants were prepared to fill in the facial bone defects, and implantation was performed. Consequently, implants fitted the individual bone defects, and satisfactory facial contouring was obtained in five cases. In one case with severe cutaneous scarring in the grafted site, it was necessary to reduce the volume of the preshaped HAP-TCP implant during surgery. In conclusion, the three-dimensional, solid, life-sized model and template are useful for preoperative detailed simulation, and the use of preshaped HAP-TCP implants based on the template probably contributes to successful reconstruction of complex facial bone deformities and to the reduction of surgical invasion, resulting in achievement of better results.

Prosthodontic guidelines for surgical reconstruction of the maxilla: a classification system of defects

Surgical reconstruction of maxillectomy defects has been described as an alternative to prosthetic rehabilitation to close the oral cavity. Advancements in microvascular surgical techniques require comprehensive treatment planning guidelines for functional rehabilitation. This retrospective study evaluated acquired maxillectomy defects after surgical reconstruction and/or prosthodontic rehabilitation in an attempt to establish surgical and prosthodontic guidelines that could be organized into a classification system. Forty-seven consecutive patient treatments of palatomaxillary reconstruction at a single facility, The Mount Sinai Medical Center (New York, N.Y.), were reviewed. All patients were rehabilitated with a tissue-borne obturator, a local advancement flap, a fasciocutaneous free flap, or a vascularized bone-containing free flap. Palatomaxillary defects were divided into 3 major classes and 2 subclasses. The aim of this defect-oriented classification system was to organize and define the complex nature of the restorative decision-making process for the maxillectomy patient.

Premaxillary augmentation: adjunct to rhinoplasty

Recession of the premaxillary area is a relatively common deformity. Typically, it presents as a mild weakness of the central maxilla, but in certain instances, such as in the Black and Asian communities, it may be moderate to severe. This condition can be compounded by a narrow nasolabial angle, recessed alar bases, and sunken cheeks. To resolve this deficiency, a new design for premaxillary augmentation is suggested. A bat-shaped premaxillary implant is used for correction. The implant is introduced by means of an intranasal or intraoral approach, while the patient is under either local or general anesthesia. Thirty-three patients have been managed for premaxillary recession and have been corrected by premaxillary augmentation. Satisfactory cosmetic results have been achieved, with only a few minor complications.

Need for evidence-based practice in prosthodontics

STATEMENT OF PROBLEM

Patients, their insurers, the courts, and the scientific community are demanding more evidence to support the effectiveness of health care strategies.

PURPOSE

This article describes evidence-based practice, its origins, and value as a way of addressing the demand for evidence of treatment effectiveness in maxillofacial prosthetics.

MATERIAL AND METHODS

A limited review of maxillofacial prosthetics literature was performed using Medline over the years 1966 to 1998. The retrieved articles were classified by methodologic design and assessed for the strength of their evidence.

RESULTS

Focused and speedy (but not necessarily comprehensive) literature searching methods are available. Critical appraisal skills are available and needed to assess the quality of evidence in support of a treatment and to maintain clinical skills.

CONCLUSION

With appropriate skills and the availability of literature searching hardware and software, evidence-based practice is a powerful means for the practitioner to establish the effectiveness of individual patient treatment, and to prevent the diminution of clinical skills over the course of a career. These skills should be included in training programs.

[Functional complementation of intra- and extra-oral implants. Apropos of a case of extensive loss of substance of the face]

The respective indications for oral or extra-oral implants lead to no confusion: stabilization of dental prostheses for the first, stabilization of maxilo-facial epitheses for the others. We demonstrate that the complementarity of the two types of implants can prove to be very useful in maintaining the maxillary dental prosthesis and the epithesis in a case of severe loss of facial substance affecting particularly the pre-maxilla. This complementary characteristic made it possible to recover fairly rapidly phonation and deglutition, and to remedy somewhat the esthetic damage. In other words to create the essential conditions for a return to everyday life.

Quantification of bone ingrowth into porous block hydroxyapatite in humans

This study sought to quantify bone ingrowth from a single bone-implant surface into porous block hydroxyapatite used in maxillofacial applications. Seventeen maxillary hydroxyapatite implants (implant time of 4-138 months, 39-month mean) were harvested for analysis from 14 patients. The implants had been placed into the lateral maxillary wall during orthognathic surgery, juxtapositioned to the maxillary sinus. Ingrowth was measured in 100-microm increments from a bone-implant interface to a depth of 1500 microm. Bone ingrowth averaged over the 14 patients (0-1100 microm depth) is described by the equation % ingrowth - 20% * (depth in millimeters) + 41.25% (R2 = 0.98, n = 10 incremental depths). Beyond 1100 microm, the average ingrowth remained constant at 15.0 +/- 0.7%. The duration of implantation also showed as affect on the percent ingrowth into the implants at the incremental depths, and the percent ingrowth asymptotically approached a maximum. Overall, the composite average data from all depths is best described by the logarithmic function % ingrowth = 15% * ln(implantation time in months) - 24.0% (R2 = 0.71, n = 14 patients). Several factors may come into play in determining bone ingrowth including the mechanical environment, the osteoconductivity of the implant material, and the osteogenic capability of the tissues in the pore spaces. Measurements of bone ingrowth are most influenced by the depth into the implant and the time the implant was in the body; the age of the patient had little affect on bone ingrowth.

Malar augmentation: a 5-year retrospective review of the silastic midfacial malar implant

OBJECTIVES

To determine the effectiveness and safety of the Silastic midfacial malar implant and to review indications, patient selection, technique, and complications of malar augmentation.

DESIGN

Five-year retrospective review of clinical cases with at least 2-year follow-up.

PATIENTS

A cohort of 60 consecutive private patients with complaints of malar hypoplasia or facial asymmetry.

SETTING

A plastic surgery clinic.

INTERVENTION

Silastic midfacial malar implants were fitted in each patient. Most underwent implantation via the canine fossa approach and in conjunction with another facial plastic procedure.

MAIN OUTCOME MEASURES

Subjective patient satisfaction, photographic grading using a visual analog scale, and complications.

RESULTS

Of the 60 patients, 51 (85.0%) reported an excellent result after at least a 2-year follow-up. Ten patients (16.7%) had some form of undesirable sequelae; however, only 4 (3.4%) of 118 implants had to be revised. Photographically, all 60 patients graded postoperative improvement.

CONCLUSIONS

Findings support the contention that the Silastic midfacial malar implant is a safe and effective alloplastic alternative to treat malar hypoplasia and facial asymmetry. The complication and revision rates are acceptable. Relative technical ease of insertion makes malar augmentation an excellent adjunct for rhytidectomy and rhinoplasty.

Effect of nitinol implant porosity on cranial bone ingrowth and apposition after 6 weeks

The present study addresses two aspects of the use of nitinol in cranial bone defect repair. The first is to verify that there is substantial bone ingrowth into the implant after 6 weeks; the second is to determine the effect of pore size on the ability of bone to grow into the implant during the early (6-week) postoperative period. Porous equiatomic (equal atomic masses of titanium and nickel) nickel-titanium (nitinol) implants with three different morphologies (differing in pore size and percent porosity) were implanted for 6 weeks in the parietal bones of New Zealand White rabbits. Ingrowth of bone into the implants and apposition of bone along the exterior and interior implant surfaces were calculated. The mean pore size (MPS) of implant type #1 (353 +/- 74 microm) differed considerably from implant types #2 (218 +/- 28 microm) and #3 (178 +/- 31 microm). There was no significant difference among implant types in the percentages of bone and void/soft tissue composition of the aggregate implants. The amount of bone ingrowth also was not significantly different among the implant types. Implant #1 was significantly higher in pore volume and thus had a significantly higher volume of ingrown bone (2.59 +/- 0.60 mm3) than implant #3 (1. 52 +/- 0.66 mm3) and a greater amount, but not significantly greater, than implant #2 (1.76 +/- 0.47 mm3). Pore size does not appear to affect bone ingrowth during the cartilaginous period of bone growth in the implant. This implies that within the commonly accepted range of implant porosities (150-400 microm), at 6 weeks bone ingrowth near the interface of nitinol implants is similar.

Facial rehabilitation by the application of osseointegrated craniofacial implants

A new approach to the facial rehabilitation of patients with congenital and acquired deformities is introduced in this short note. This method involves having a bone implant that allows the anaplastologist to fabricate a custom prosthesis for use in patients with disfigurement. The design of the implantation site is done before the surgical procedure. The titanium oxide fixtures and abutments are submerged and extrude through the skin by a small window. The attachment for the replacement part is achieved by using a metallic bar or magnets. A small space is left at the interface for ventilation of the skin and to avoid any maceration that will compromise the integrity and long-term accepted outcome. This new method is not a replacement of the traditional techniques but an augmentation for the accepted methods in facial rehabilitation.

Surgical and prosthetic treatment of congenital absence of the nose: a case report

This paper presents a case of a 5-year old girl with a congenital absence of the nose. Congenital arrhinia is a very rare malformation of the midfacial bones. The difficulties of treating a child with this abnormality are discussed.

Maxillofacial prosthodontics and reconstruction: a Canadian view

A craniofacial osseointegration and maxillofacial prosthetic rehabilitation unit in Edmonton, Canada was visited by the author as part of a higher specialist training programme. The unit has an international reputation as a centre of excellence for the treatment of patients with head and neck abnormalities. The report examines the activities of the unit and how it achieves its 'patient centred' approach to care.

[Is a maxillary prosthesis difficult for patients with trismus?]

Of patients with a postoperative maxillary defect, around 30% are though to have trismus to some extent. In these patients, some difficulty in fabricating a maxillary prosthesis is expected. In this study, 54 patients with trismus were compared with a control group to find some proof of difficulty in making a maxillary prosthetics. Fifty-four of trismus less than 20 mm of a mandibular stroke were experienced out of 185 patients with maxillary prosthetics between October 1984 and October 1992. The trismus was divided into 4 groups of less than 5 mm (1 case), 5 mm-10 mm (10 cases), 11 mm-15 mm (19 cases), and 16 mm-20 mm (24 cases). These case were analyzed by in taking an impression failure, average weight of the prosthesis, time needed to complete the prosthesis and some special form of prosthesis. No apparent differences among the 4 groups or with the control group were found. The cause of the difficulty in making a prosthesis for such patients with trismus are suggested not to be simply due to the range of mouth opening but also to the complexed space formed by the dental defect, alveolar bone defect, spreadability of the lip and the cheek, the mandibular stroke and the so-called scar bundle of the cheek next to the defect.

An algorithm for maxillectomy defect reconstruction

A maxillectomy defect creates a communication from oral cavity to nasal cavity that may extend to the orbit. Functional deglutition and speech problems with a significant soft tissue deficit ensue. This paper defines the reconstruction options for the spectrum of inferior partial maxillectomy defects to midface-orbital exonerations. Treatment protocols from maxillectomy patients treated in January 1991 to February 1996 at a major tertiary care institution were reviewed (n = 108). An ascension of care from dental obturator, nonvascularized graft, local flap, regional flap, and free tissue grafts (n = 28) is described. These data and experience were organized to provide a treatment algorithm to assist in presurgical planning for maxillectomy reconstruction.

The use of percutaneous implants for the prosthetic rehabilitation of orbital defects in irradiated cancer patients: a report of clinical outcomes and complications

This retrospective study evaluated the use of percutaneous craniofacial implants for the prosthetic rehabilitation of patients with a history of orbital exenteration and irradiation for oncologic tumors of the head and neck. A total of 24 implants were placed in six patients. All implants were determined to be osseointegrated at the time of uncovering. Three implants were subsequently resubmerged beneath the soft tissue because of positional interferences with prosthesis fabrication. The remaining 21 implants were ultimately used to retain six orbital prostheses. Two implants failed to maintain osseointegration during the follow-up period and were subsequently removed without complications. This represents an overall integration success rate of 90.5% over a mean follow-up period of 32.8 months (range = 11 to 68 months). The significance of these findings and their relationship to comparable reports in the literature are discussed.

Immediate maxillofacial prosthodontic rehabilitation after radical mid-face tumor resection

Mid-facial surgical defects can adversely affect a patient's esthetics and psychological well-being. Fabrication of a definitive mid-facial prosthesis can be a time-consuming procedure. It is crucial to minimize the time between the tumor resection and initial prosthetic rehabilitation. This article describes a method for rapid fabrication of a transitional facial prosthesis for mid-facial defects.

Lactosorb panel and screws for repair of large orbital floor defects

In a series of five patients with extensive fractures of the orbital floor, we used a biodegradable sheet for bridging of the bony defects. To achieve optimal support of the orbital contents in their anatomically correct position, we fixed the sheet with at least two resorbable screws to the infraorbital rim. This new technique appears to be superior to conventional methods because it offers reproducible results without the need for secondary interventions.

Effects of implant anchorage on midface prostheses

STATEMENT OF PROBLEM

Acquired midface defects may produce functional and psychologic impairments that adversely effects a patient's quality of life. Conventional prostheses may lack adequate retention and stability, diminishing the patient's confidence that the prosthesis will remain in place during routine activities.

PURPOSE

The experience with and patient response to endosseous implants in prosthetic restoration of midface defects is presented in this study.

MATERIAL AND METHODS

Five patients in age from 36 to 88 years were treated with 19 titanium endosseous root-form implants to provide retention and stability for prostheses. Patients responded to a questionnaire rating overall use, effectiveness, and satisfaction of their prosthesis, before and after the use of implants.

RESULTS

All 19 implants were judged to be osseointegrated at abutment connection. Of the 17 implants used prosthetically, 14 (82%) remained osseointegrated and 3 (18%) failed. Analysis of the questionnaire tends to indicate an improvement of the quality of life for the patients with an implant-retained prosthesis.

[The management of extra-oral implants. Anachronisms and paradoxes]

Used in France for ten years and in Sweden since 1977. Extra-Oral Implants (EOI) represent one of the new therapeutic approach of facial defects treatment by maxillo-facial prostheses fixed on implants and of some transmission deafnesses. Audiologic applications are free of charges for the patient but not the prosthetic applications; the authors note this paradox and some other anachronisms. Finally the authors wonder why Extra-Oral implantology is a "correct" science and why Intra-Oral Implantology remains absent from the Administrative texts as if it was a sort of doubtful therapy without scientific principles.

Long-term ingrowth and apposition of porous hydroxylapatite implants

Bone implant materials are often used to fill in bone gaps that frequently result from orthognathic and craniofacial reconstruction. The substrate hydroxylapatite (HA) is commonly implanted into the bone voids, resulting from these conditions due to its established biocompatibility and osteoconductive properties. The porous structure of HA provides a three-dimensional guideline for fibrovascular ingrowth, facilitating the process that ultimately results in the deposition of new bone. Porous HA (Interpore, 200) implants were implanted in the mandible or maxilla of nine humans and removed after 14-30 months (19.1-month mean). There was no evidence of an inflammatory response. The sample composition and apposition against the implant were determined using point counting and a digitizing tablet and software. Percent ingrowth in available space (%IAS) was defined as %Bone/(%Bone + %Void). A new measure of implant saturation (%IAS-%Apposition of bone) was established to help determine the fundamental manner in which long-term HA implants incorporate bone. In the mean, the samples were composed of 27% bone, 21% void, and 53% implant. The apposition percentages averaged 60% bone, 16% void, and 24% soft tissue. The %IAS averaged 58%, and implant saturation averaged -3%, indicating that a near-balance between the implant and surrounding bone has been established.