Extraoral implants in the rehabilitation of craniofacial defects: implant and prosthesis survival rates and peri-implant soft tissue evaluation

PURPOSE

Few reports have evaluated cumulative survival rates of extraoral rehabilitation and peri-implant soft tissue reaction at long-term follow-up. The objective of this study was to evaluate implant and prosthesis survival rates and the soft tissue reactions around the extraoral implants used to support craniofacial prostheses.

MATERIALS AND METHODS

A retrospective study was performed of patients who received implants for craniofacial rehabilitation from 2003 to 2010. Two outcome variables were considered: implant and prosthetic success. The following predictor variables were recorded: gender, age, implant placement location, number and size of implants, irradiation status in the treated field, date of prosthesis delivery, soft tissue response, and date of last follow-up. A statistical model was used to estimate survival rates and associated confidence intervals. We randomly selected 1 implant per patient for analysis. Data were analyzed using the Kaplan-Meier method and log-rank test to compare survival curves.

RESULTS

A total of 150 titanium implants were placed in 56 patients. The 2-year overall implant survival rates were 94.1% for auricular implants, 90.9% for nasal implants, 100% for orbital implants, and 100% for complex midfacial implants (P = .585). The implant survival rates were 100% for implants placed in irradiated patients and 94.4% for those placed in nonirradiated patients (P = .324). The 2-year overall prosthesis survival rates were 100% for auricular implants, 90.0% for nasal implants, 92.3% for orbital implants, and 100% for complex midfacial implants (P = .363). The evaluation of the peri-implant soft tissue response showed that 15 patients (26.7%) had a grade 0 soft tissue reaction, 30 (53.5%) had grade 1, 6 (10.7%) had grade 2, and 5 (8.9%) had grade 3.

CONCLUSIONS

From this study, it was concluded that craniofacial rehabilitation with extraoral implants is a safe, reliable, and predictable method to restore the patient's normal appearance.

Two-piece impression procedure for implant-retained orbital prostheses

Obtaining an accurate impression of facial tissues with undercuts and extraoral implants has always been a challenge for both clinicians and patients. This report describes a three-step, two-piece technique that enables an accurate and comfortable impression of undercut tissues and extraoral implants in an orbital defect. An impression of the basal tissue surface of the defect area was made using a medium-body polyether impression material followed by an impression of the entire face of the patient made with a polyvinyl siloxane (PVS) impression material. First, the PVS impression material was removed; second, the impression posts were removed from the magnets; and third, the polyether impression was removed from the defect. The impression posts were attached to the implant analogs and placed in the negative spaces in the polyether impression. The polyether impression, which carries the implant analogs and impression posts, was placed in the PVS impression through the negative spaces. This technique minimizes trauma to the soft tissues and implants during impression making and also does not require additional materials.

Enucleation and evisceration: 20 years of experience

OBJECTIVE

To determine the indications, relative frequencies, surgical times, and complications for enucleation and evisceration performed at a single academic center.

METHODS

Medical records of all patients who underwent an enucleation or evisceration between January 1st, 1990 and December 31st, 2009 at a single academic center were reviewed. Patient demographics and surgical indications, times, and complications were recorded.

RESULTS

A total of 85 eyes in 85 patients underwent enucleation (n = 31; 36%) or evisceration (n = 54; 64%) during the study period. Almost all patients were of African descent (96%). The most common underlying cause leading to eye removal was trauma. On average, eviscerations (47.3 ± 10.3 minutes) took significantly less time to perform than enucleations (89.6 ± 10.1 minutes; p < 0.01). Complications included implant exposure, infection, lower lid laxity, fornix insufficiency, and need for subsequent surgery; the occurrence of these complications was found to be similar between the two groups (p = 0.77). No case of sympathetic ophthalmia or inadvertent evisceration of an eye with an occult intraocular malignancy was noted. From the first decade for which data were available (1990- 1999) to the second decade (2000- 2009), the average number of enucleations decreased (p = 0.02) and the average number of eviscerations (p = 0.04) increased.

CONCLUSION

Evisceration was found to be a safe and quicker alternative to enucleation in our study. A change in surgical preference from enucleation to evisceration was seen during the 20-year study period.

Quality of life of eye amputated patients

PURPOSE

To evaluate eye-amputated patients' health-related quality of life, perceived stress, self-rated health, job separation because of illness or disability and socioeconomic position.

METHODS

Patients were recruited from a tertiary referral centre situated in Copenhagen. Inclusion criteria were eye amputation, i.e. evisceration, enucleation, orbital exenteration or secondary implantation of an orbital implant during the period 1996-2003, and participation in a previous investigation (2005). In total, 159 eye-amputated patients were included, and completed a self-administered questionnaire containing health-related quality of life (SF-36), the perceived stress scale and answered questions about self-rated health, job changes because of illness or disability and socioeconomic status. These results were compared with findings from the Danish Health Interview Survey 2005.

RESULTS

The eye-amputated patients had significantly (p < 0.05) lower scores (poorer health) on all SF-36 subscales and more perceived stress compared to the general population. In all, 43.3% of the patients rated their health as excellent or very good compared to 52.1% of the general population. In total, 25% of the study population has retired or changed to a part-time job because of eye disease. The percentage of eye amputated patients, who were divorced or separated, was twice as high as in the general population.

CONCLUSION

The impact of an eye amputation is considerable. The quality of life, perceived stress and self-rated health of many eye-amputated patients are drastically changed. Eye amputation has a marked negative influence on job separation because of illness or disability and on socioeconomic position.

The use of mersilene mesh for wrapping of hydroxyapatite orbital implants: mid-term result

PURPOSE

To report the results of Mersilene mesh wrapped hydroxyapatite orbital implantation.

MATERIALS AND METHODS

Records of 63 patients operated between April 2002 and March 2006 were retrospectively reviewed. Parameters studied included sex, cause of enucleation, length of follow-up after operation, implant exposure, secondary implantation, and surgeon experience. Student's t-test and χ(2) were used for comparison group having implant exposure and those without implant exposure.

RESULTS

The rate of exposure with use of Mersilene mesh was found to be 4.7%. Gender and cause of enucleation did not influence incidence of implant exposure in this study. The surgeon related factor, reported in terms of oculoplasty surgeon and non-oculoplasty surgeon, was a statistically significant factors that affected implant exposure.

CONCLUSION

Mersilene showed favorable results in wrapping of hydroxyapatite orbital implants.

One-stage explant-implant procedure of exposed porous orbital implants

PURPOSE

To investigate the risks of implant exposure after a combined explant-implant procedure in patients with an exposed porous orbital implant.

METHODS

Twenty-four consecutive patients who had a combined explant-implant procedure of an exposed hydroxyapatite (21) or porous polyethylene (3) orbital implant from January 2000 to February 2009 were included. The patient records were reviewed; patients were interviewed by telephone and invited for a clinical examination. Histopathological examination was carried out on the removed implants. Main outcome measures were: presence of exposure of the new implant or not, patient graded satisfaction with the cosmetic result, and presence of poor motility.

RESULTS

None of the new implants became exposed or infected in the follow-up period of 25 [3-94] months (median [range]). The patients scored their satisfaction with the cosmetic result to a median score of 9 (range 5-10). Poor motility was present in six of 17 patients. Micro-organisms were identified in three removed implants and signs of inflammation were present in 20 removed implants.

CONCLUSIONS

If a decision of implant removal has been made, it is safe to replace the implant at the same procedure in sockets without profound signs of infection. The procedure carries a possible risk of poor motility.

[Comparative experimental study of current implant materials used in orbital surgery]

Reconstructive orbital procedures are often associated with the use of different implant materials, that may sometimes cause complications resulting in surgery efficacy impairing and need of reoperation. At the present time in Russia and abroad various orbital implants are used though there are no experimental or clinical studies comparing implant materials used In this study comparative experimental morphological investigation of biointegrative characteristics of 6 current orbital implant materials was performed, tissue reactions in response to implantation is described in details in laboratory animals, recommendations for implant use in clinic are given.

Stability measurements of craniofacial implants by means of resonance frequency analysis: 1-year clinical pilot study

PURPOSE

The purpose of this pilot study was to apply resonance frequency analysis (RFA) to measure the clinical stability of craniofacial implants and compare the RFA measurements over a 12-month period.

MATERIALS AND METHODS

Patients with auricular or orbital defects were treated with prostheses retained by two or three implants. After healing periods of 3 months for auricular implants and 6 months for orbital implants, prostheses were fabricated. RFA measurements were performed immediately after implant placement, at abutment connection, and at 6 and 12 months. All stability measurements were repeated three times for each implant, and the mean value was used for analyses. For measurements performed after prosthesis delivery, connecting bars and abutments were removed prior to RFA. The stability of both types of implants was compared at different time intervals.

RESULTS

Fifty-four implants were placed in 10 patients with auricular defects (26 implants) and 10 patients with orbital defects (28 implants). All auricular implants survived, and four orbital implants in four different patients failed. For auricular implants, statistically significant differences in stability values were noted between implant placement, abutment connection, and 6 months; there was no significant difference between 6 and 12 months. For orbital implants, no significant differences were found between implant placement and abutment connection, a significant increase was observed at 6 months, and no significant difference was seen between 6 and 12 months. No significant differences were found for auricular versus orbital implants between placement and abutment connection, but auricular implants showed significantly higher stability values than orbital implants at 6 and 12 months.

CONCLUSIONS

The stability of surviving auricular and orbital implants increased with time according to RFA. Prior to failure, the failed implants showed RFA values that were below the mean.

Evisceration with four anterior relaxing incisions and circumferential posterior sclerotomies with porous polyethylene orbital implants: an 8-year study

PURPOSE

To present long-term follow-up data on eviscerations carried out with scleral modification and placement of spherical porous polyethylene implants.

METHODS

We conducted a retrospective, interventional study on eviscerations performed with four anterior relaxing incisions and posterior sclerotomies made circumferentially behind the equator at approximately 330° and placement of porous polyethylene spherical implant, performed between March 2000 and August 2007 by a single surgeon. Patient age, sex, causative diagnosis, axial length, implant size, follow-up duration, complications and treatment were recorded.

RESULTS

In total, 92 patients were identified. The mean implant size was 19.46 mm. During the follow-up period (mean: 60 months, range: 19-107 months), there were no cases of implant exposure. In some patients, mild discharge, ptosis and conjunctival cysts developed.

CONCLUSIONS

Primary evisceration with four anterior relaxing incisions and posterior sclerotomies made circumferentially behind the equator at approximately 330°, combined with porous polyethylene orbital implant placement, is a useful technique for treating a variety of end-stage eye diseases.

Dermis-fat graft for treatment of exposed porous polyethylene implants in pediatric postenucleation retinoblastoma patients

PURPOSE

To demonstrate the use of the autogenous dermis-fat graft for the treatment of porous polyethylene implant exposure and volume augmentation in postenucleation retinoblastoma children.

DESIGN

Retrospective, interventional case series.

METHODS

Ten children who received a dermis-fat graft at Seoul National University Hospital between July 1, 2005 and January 31, 2010 were included in this study. The patients had undergone unilateral enucleation for retinoblastoma, and received a subconjunctival dermis-fat graft to repair implant exposure and simultaneously correct enophthalmos. The clinical characteristics of the patients, rate of graft survival, and complications were analyzed. The cosmetic outcome was assessed using a grading system.

RESULTS

All patients had enucleation using porous polyethylene implant as a primary orbital implant. The average time to exposure was 89.1 ± 22.4 months and the median size of defect was 2 × 3 mm. With a mean follow-up of 28 months, 9 of 10 patients showed well-survived graft without re-exposure. One patient who experienced a graft failure managed with implant rotation and a scleral graft. Seven patients showed significant improvement of enophthalmos.

CONCLUSIONS

Implantation of an autogenous dermis-fat graft is a procedure that can be effectively used to treat porous polyethylene implant exposure and simultaneously correct enophthalmos. Use of this procedure can be particularly advantageous for pediatric postenucleation patients.

Ultrastructural investigation of intact orbital implant surfaces using atomic force microscopy

This study examined the surface nanostructures of three orbital implants: nonporous poly(methyl methacrylate) (PMMA), porous aluminum oxide and porous polyethylene. The morphological characteristics of the orbital implants surfaces were observed by atomic force microscopy (AFM). The AFM topography, phase shift and deflection images of the intact implant samples were obtained. The surface of the nonporous PMMA implant showed severe scratches and debris. The surface of the aluminum oxide implant showed a porous structure with varying densities and sizes. The PMMA implant showed nodule nanostructures, 215.56 ± 52.34 nm in size, and the aluminum oxide implant showed crystal structures, 730.22 ± 341.02 nm in size. The nonporous PMMA implant showed the lowest roughness compared with other implant biomaterials, followed by the porous aluminum oxide implant. The porous polyethylene implant showed the highest roughness and severe surface irregularities. Overall, the surface roughness of orbital implants might be associated with the rate of complications and cell adhesion.

The effect of autologous serum eye drops on the conjunctivalization over exposed porous polyethylene orbital implant (Medpor(®)) in the rabbit model

PURPOSE

To assess the efficacy of autologous serum eye drops (AS) in enhancing conjunctivalization over a scleral patch graft on exposed porous polyethylene orbital implant (Medpor(®)).

METHODS

Eighteen rabbits were underwent evisceration, implantation of Medpor(®) and homologous scleral patch graft. The conjunctival edge was sutured leaving 5 mm-diameter circular defect. In group A, 20% AS were applied 8 times a day and only balanced salt solution was applied in group B. Digital anterior segment photography was obtained 1, 3, 7, 10, 14, and 21 days after surgery and analyzed with Image Pro Plus(®) software.

RESULTS

In the early postoperative period, the average conjunctival growth rate (mm(2)/day) was faster in group A, but failed to show statistical significance (3.79 vs. 3.03, p = 0.26 in 1~3days, 2.39 vs. 1.80, p = 0.59 in 4- days, 0.03 vs. -0.02, p = 0.94 in 7-10 days, Mann-Whitney test). The complete healing rate was higher (67% vs. 56%, p = 0.5, Fisher's exact test) and the mean elapsed time for complete healing (days) was shorter in group A (17.3 vs. 18.2, p  = 0.83, Mann-Whitney test), but did not show a statistically significant difference.

CONCLUSION

In a rabbit model, 20% AS did not appear to facilitate the healing of small conjunctival defects of exposed porous orbital implant.

Enduragen patch grafts for exposed orbital implants

PURPOSE

To present a new technique using the recently introduced Enduragen(®) material (Tissue Science Laboratories) as a patch graft for exposed ocular implants.

METHODS

A retrospective, interventional, non-comparative case series of 3 patients who had Enduragen patch grafts for the closure of Tenon's capsule and conjunctiva over exposed ocular implants. Medical records were reviewed and the following parameters were collected: age, gender, indication for surgery, type of surgery, laterality, type of orbital implant, complications after repair and length of follow-up.

RESULTS

Three patients were identified, 2 males and 1 female. One patient had a secondary quad-motility implant with supertemporal exposure. The second patient had a secondary implant with a fistula at the lateral aspect of the socket. The third patient had a centrally exposed primary hydroxyapatite implant. All patients received Enduragen patch grafts to cover the implant. Follow up ranged from 40 to 43 months (mean, 41.3 months; SD, ± 1.5). None of the 3 patients had any signs of implant re-exposure at the time of the last post-operative visit. There were no intra-operative or early complications observed.

CONCLUSIONS

This consecutive case series suggests that Enduragen could be used as a safe and effective patch graft for exposed ocular implants. However, a larger prospective study with longer follow-up would be useful in further defining the indications and limitations of the Enduragen patch graft for the treatment of exposed orbital implants.

MR imaging of progressive enhancement of a bioceramic orbital prosthesis: an indicator of fibrovascular invasion

The physical properties of bioceramics have made them ideal for a variety of prosthetic devices. Their porous structure allows fibrovascular tissue to invade the implant and secure it and provides a surface for muscular attachment. This process has been well-documented in animal studies; however, this case report describes the periodic imaging changes seen in a 67-year-old man following placement of a bioceramic orbital prosthesis.

[Rationale for implant insertion after enucleation of eyes with uveal melanoma]

Results of retrospective analysis of medical charts of 328 patients after enucleation due to uveal melanoma (UM) are represented. Our study showed that recurrent tumor occurs in 2.44% cases. The main reasons of recurrence are scleral invasion or tumor damage during surgery. After enucleation due to juxtapapillary UM recurrence is rare and occurs after long-term follow-up. Thus after enucleation due to UM implant insertion is possible in case of scleral integrity and absence of macroscopically apparent tumor extension beyond sclera.

[Study of the three-dimensional structure and biointegrative characteristics of porous orbital implant materials]

Plastic repair operations in ophthalmic surgery frequently require the use of various biological and artificial implants. The biointegrative properties of implants are provided by the physicochemical characteristics of the material that is used to make them, by the three-dimensional structure of an implant and its immunological characteristics. The authors comparatively studied the three-dimensional structure of a Carbotexim-M carbonic felt, porous polyethylene, polytetrafluoroethylene, demineralized bone alloimplant, and marine coral hydroxyapatite, which are employed in orbital surgery and also examined the adhesion of fibroblasts to their surface. Comparative study using scanning electron microscopy could reveal the specific features of the relief and parameters of the threshold space of the study implant materials. A method was developed to estimate cell adhesion to the implant materials, by taking into account three-dimensional structure of their surface.

[Role of primary and stepwise prosthetic replacement in the rehabilitation of subjects with anophthalmos]

The study covered 1980 patients with anophthalmos and a cosmetically poor blind eye, who were followed up in the ocular prosthesis room, Helmgoltz Institute of Eye Diseases. The optimal periods of primary and stepwise prosthetic replacement are defined and standard ocular prostheses of the most appropriate shape and size are recommended depending on the specific features of the conjunctival cavity and stump in this period. Recommendations are given on the application of ocular prostheses in congenital pathology and subatrophy.

Rigid nylon foil-anchored polytetrafluoroetyhlene (Gore-Tex) sheet stenting for conjunctival fornix reconstruction

PURPOSE

To describe an operative technique that deepens foreshortened conjunctival fornices by providing a scaffold for epithelialization that opposes contractile forces during wound healing.

DESIGN

Retrospective interventional case series.

PARTICIPANTS

Seventeen patients with anophthalmic sockets containing foreshortened conjunctival fornices.

METHODS

Conjunctival fornices was reconstructed with stents of expanded polytetrafluoroethylene (e-PTFE) sheet draped over rigid, 0.8-mm thick-nylon strips that were anchored to the orbital rim. Preoperative and postoperative symptoms, prosthesis retention, fornix depth, and lagophthalmos were assessed.

MAIN OUTCOME MEASURES

Prosthesis retention, fornix depth, and lagophthalmos.

RESULTS

All 17 patients had preoperative inability to retain their prosthesis. After postoperative follow-up of 47+/-43 months, retention was improved in all patients and was entirely satisfactory in 15 (88%) patients. After reconstruction, the repaired fornix was deep in 7 (41%) patients, adequate to retain a prosthesis in 9 (53%), and shallow in 1 (6%). Lagophthalmos improved in 15 (88%) patients and remained unchanged in 2 (12%). The superior fornix was reconstructed concurrently with the inferior fornix in 6 patients. In these patients, the superior fornix improved to deep (3 patients; 50%) or adequate (2; 33%). In 1 (17%) patient, it remained shallow.

CONCLUSIONS

Rigid, nylon foil-anchored e-PTFE stenting opposes postoperative contracture, improving prosthesis retention, and lagophthalmos. It does not require an additional surgical site for graft harvesting.

The use of autologous dermis grafts for the reconstruction of the anophthalmic socket

PURPOSE

The main objectives of enucleation, evisceration or secondary orbital implants are to replace orbital volume and obtain good motility and adaptation of the implant and the external prosthesis. We describe our experience using autologous dermis graft sutured to Tenon and conjunctiva following evisceration, enucleation and any reconstruction requiring either a primary or secondary orbital implant, even those with large tissue loss.

MATERIALS AND METHODS

A retrospective case series of patients who received an autologous dermis graft to assist in closure of a Tenon's capsule and conjunctiva at the time of placement of secondary orbital implants or evisceration or enucleation with fornices retraction or tension in tissues. We also describe how and from where to take the dermis graft.

RESULTS

72 patients were included and all received orbital porous polyethylene implants: 28 patients had secondary orbital implants, 36 patients had evisceration and 8 patients had enucleation. Implant size was 20 mm in most cases, but went to 22 mm. Follow-up ranged from 3 to 36 months. No intraoperative complications were observed in donor or receptor area. 8 cases had incipient ischemia of the dermis graft, but were treated and resolved with autologous serum.

CONCLUSIONS

Implant exposure is due to bad surgical technique, an inadequate implant size or excessive tension on the suture. Dermis autologous graft allows moving the orbital implant anteriorly because it replaces surface to suture Tenon and conjunctiva without tension, so a good adaptation of a thinner external prosthesis is possible, resulting in better motility.

Fabrication of a surgical template for orbital implant placement: a case report

Implant placement in orbital sites is challenging because of limited bone volume and poor bone quality. Preoperative optimal implant planning and intraoperative guides are important to ensure success. This article describes the use of computer simulation for implant insertion and fabrication of a surgical template as a drilling guide for orbital implant placement. A 29-year-old woman with a right orbital defect underwent computerized tomographic scanning, and the data were processed with interactive software to simulate orbital implant placement. A surgical template that served as a drilling guide was designed and fabricated to transfer orbital recipient site information from the three-dimensional computer model into the actual orbital implant sites. Three craniofacial implants were placed in the 7:00, 8:00, and 11:00 positions. No unexpected complications or injuries were encountered during the surgery. Magnetic abutments were attached to the implants 2 weeks later. The definitive facial prosthesis was fitted 6 months later, with excellent esthetic results. The surgical template contributed to the success of this treatment.