Treatment of midfacial defects using prostheses supported by ITI dental implants

Maxillofacial prosthetics and digital technologies: Cross-sectional study of healthcare service provision, patient attitudes, and opinions

PURPOSE

Digital technologies are continuously improving the accuracy and quality of maxillofacial prosthetics, but their impact on patients remains unclear. This cross-sectional study aimed to analyze the impact of facial prosthetics service provision, patients' perception, and digital technology on prostheses construction.

MATERIALS AND METHODS

All patients who presented for evaluation and management of facial defects between January 2021 and December 2021 at the ENT clinic were eligible for study enrollment. Patients requiring prosthetic reconstruction of their missing facial parts were included in the study. Forty-five questionnaires were delivered, inquiring about the patients' prosthetic demographics, prosthesis manufacture using 3D technologies, and their perceptions and attitudes.

RESULTS

A total of 37 patients responded (29 males, eight females; mean age 20.50 years). The congenital cause was the highest among other causes (p = 0.001) with auricular defects being the highest (p = 0.001). A total of 38 prostheses were constructed and 17 prostheses were retained by 36 craniofacial implants (p = 0.014). The auricular and orbital implants success rates were 97% and 25%, respectively. The implant locations were digitally planned pre-operatively. Digital 3D technologies of defect capture, data designing, and 3D modeling were used and perceived as helpful and comfortable (p = 0.001). Patients perceived their prosthesis as easy to handle, suited them, and they felt confident with it (p = 0.001). They wore it for more than 12 h daily (p = 0.001). They were not worried that it would be noticed, and found it comfortable and stable during various activities (p = 0.001). Implant-retained prosthesis patients were more satisfied with it, and found it easy to handle and stable (p = 0.001).

CONCLUSIONS

Congenital defects are the main cause of facial defects in the study country. The overall acceptance of maxillofacial prostheses was good, showing high patient perception and satisfaction. Ocular and implant-retained silicone prostheses are better handled, more stable, and the latter is more satisfying than traditional adhesive prostheses. Digital technologies save time and effort invested in manufacturing facial prostheses.

Rehabilitation of a Midfacial Defect Using a Two-Piece Maxillofacial Prosthesis: A Case Report

Maxillofacial defects and their rehabilitation are a major concern in this socially productive era. The rehabilitation of these massive defects in the oral and maxillofacial region poses a challenge to the prosthodontist in terms of selection of material, retentive aids, the adaptive capability of the patient, and cost. This case report describes the management of the midfacial defect involving the orbit, zygoma, maxilla, and their soft tissue counterparts with a removable silicone extraoral compartment and an acrylic intraoral compartment, which are retained with strong cobalt samarium magnets, an elastic loop around the occiput, and spectacles. The maxillofacial prosthesis fabricated for this patient restored the patient’s facial esthetics, speech, dental articulation, lip support, mastication, and anterior maxillary seal.

Retrospective study of treatment outcomes with implant retained auricular prostheses at a tertiary referral care centre

Purpose

To discuss the indications, technical steps for fabrication of implant retained auricular prosthesis (IRAP), and treatment outcome at various follow up visits.

Materials and methods

We performed retrospective data collection of all consecutively treated patients referred to us for auricular reconstruction from 2006 till 2018. Each case was analysed for: feasibility of autogenous reconstruction vs IRAP, surgical procedure, type of anaesthesia, type of implants, soft tissue response, implant success and survival rate, prosthetic attachment, aesthetic outcome, complications and patient acceptance. Procedure for fabrication of IRAP has also been written in detail to benefit readers.

Results

IRAP was considered feasible and performed in eight out of 27 patients referred for auricular reconstruction. 20 implants were placed and total 10 prostheses were fabricated. Implant success rate and survival rate was 90% and 100% respectively till last follow-up of each patient. Bar and clip attachments were used in 60% and stud attachments in 40% of prostheses. After stage II surgery, grade I soft tissue inflammation was reported around two implants (10%), and grade III around one implant (5%). Implant with grade III inflammation showed features of recurrent infection and thus was left buried under soft tissues. These prostheses were aesthetically pleasing in all cases in the early post-operative period.

Conclusions

A systematic, step wise procedure with multi-disciplinary approach is a key to success for the fabrication of implant retained auricular prosthesis.

Total nasal reconstruction: a review of the past and present, with a peak into the future

PURPOSE OF REVIEW

The goal of this article is to review the complex topic of total nasal reconstruction and present a wide range of options for completing this difficult surgical procedure.

RECENT FINDINGS

Nasal reconstruction has a long history dating back thousands of years. Some historical techniques still exist today, including the paramedian forehead flap. The introduction of free tissue transfer and other pedicled flaps has provided multiple options for the reconstructive surgeon. The future of nasal reconstruction will include facial transplantation and likely bioengineered tissues.

SUMMARY

The principles of nasal reconstruction have gone unchanged for decades; however, the techniques to meet the principles have. The current reconstructive methods of grafts, free flaps, and pedicled flaps used to replace lining, structure, and skin will likely be used for several years to come. However, the use of facial transplantation has proved effective and bioengineered tissues present an exciting future for organ replacement.

Evaluation of Some Mechanical Properties of a Maxillofacial Silicon Elastomer Reinforced with Polyester Powder

Maxillofacial silicone elastomers are used to replace and reconstruct missing facial parts for patients with trauma or a certain disease. Although commonly favorable silicone elastomers are not ideal in properties, many studies have been carried out to improve their mechanical properties and to come out with ideal maxillofacial prosthetic materials, so as to render patients with the best maxillofacial prostheses. The aim of the current study is to evaluate the effect of addition of different concentrations of polyester powder on hardness, tear strength, surface roughness, and tensile strength of maxillofacial A-2186 RTV silicone elastomers. Polyester powder was added to the silicone elastomer in the concentrations of 1%, 3% and 5% by using an electronic digital balance, compared with the control group of 0% polyester filler. The shore A hardness test was done according to ASTM D 2240 standards. The tear test was done according to ASTM D624 type C standards. The tensile test was done according to ISO specification number 37:2011. The surface roughness test was performed according to ISO 7619-1 2010 specifications. The data collected were then analyzed using one-way analysis of variance (ANOVA) and post hoc and Fisher’s LSD tests. All three groups showed a highly significant increase in tear strength, tensile strength, hardness, and roughness, compared to the control group. Reinforcement of A-2186 Platinum RTV Silicone Elastomer with 5% polyester significantly improved the mechanical properties tested in this study.

Implant prognosis in irradiated versus non-irradiated nasal, orbital and auricular sites

The purpose of this systematic review was to evaluate implant survival in irradiated nasal, auricular, orbital sites and to compare them with non-irradiated respective sites. Four electronic databases and seven related journals were searched until December and March 2018, respectively. A total of 7892 articles were identified, 18 of which were included in this review; one non-randomized clinical trial, two prospective cohort, eight retrospective cohort and seven cross-sectional studies. Using the ROBIN-I Cochrane tool for risk assessment, 13 studies were judged at serious, one at moderate and four at critical risk of bias. Thirteen were included in 18 meta-analyses, the results of which showed a significant difference between irradiated and non-irradiated sites, favouring non-irradiated with risk ratio (RR) = 0.93, 95% confidence interval (CI) 0.89-0.97, P=0.001. Comparisons among nasal, auricular and orbital sites revealed no significant differences, whether in irradiated or non-irradiated patients at P<0.05. Hence, it was concluded that, within the limitations of this review, survival of craniofacial implants is negatively affected by radiotherapy, especially in orbital sites. Level of evidence is moderate. Therefore, further prospective cohort studies with calculated sample sizes, restricted or properly managed confounders and no deviations from intended interventions might produce different results.

Direct 3D Printing of Flexible Nasal Prosthesis: Optimized Digital Workflow from Scan to Fit

A maxillofacial prosthesis is a successful treatment modality to restore missing facial parts. Digital technologies and 3D printing are employed in constructing facial prostheses such as ears; however, their application is still partial, and final prostheses are usually manufactured conventionally using stone molds. This report aims to introduce a complete digital workflow to construct a nasal prosthesis and compare it to the conventional workflow of a patient requiring a nasal prosthesis. A computer tomography scan showing the defect was exported to specialized software to create 3D reconstructions of the patient's face and underlying bone. The nose was digitally designed restoring facial esthetics, anatomy, shape, and skin color. Different skin tones were digitally matched to skin tissues adjacent to the defect area using the Spectromatch system. The design was 3D printed in flexible and colorful material at 16 μm resolution using a 3D printer. External color pigmentations were applied to the nose for optimum esthetics, and the prosthetic nose was sealed in silicone and left to heat polymerize for 15 minutes. The prosthetic nose was retained in place using biomedical adhesive, and the patient was pleased with it. This report proposes a complete digital workflow to directly design and fabricate a prosthetic nose of acceptable esthetics. Such a workflow can lead to enhanced prosthesis reproducibility and acceptability and may become an effective treatment option for treatment of patients with facial defects.

Effect of the simulated Indian and Mediterranean climates on the Shore A hardness of maxillofacial silicone

Purpose:

The purpose of this study was to assess and compare the effect of the simulated Indian and Mediterranean climates on the Shore A hardness of a commercially available nonpigmented room temperature vulcanizing maxillofacial silicone.

Materials and Methods:

Sixty specimens were fabricated from A-2000 silicone material (Factor II), using a stainless steel mold of dimension 20 mm × 2 mm. The initial Shore A hardness was noted using a digital durometer. Thirty samples were subjected to the simulated Mediterranean climate (Group I), and the remaining thirty samples were subjected to the Indian tropical climate (Group II) in an accelerated weather chamber to simulate 1 year of clinical use. Final Shore A hardness was noted. A one-way ANOVA and Bonferroni post hoc tests were performed for the Shore A hardness at P < 0.05.

Results:

The mean initial Shore A hardness for both the groups was 24.9833. After accelerated weathering, Group I showed mean Shore A hardness of 33.0000 whereas Group II showed mean Shore A hardness of 38.0000.

Conclusions:

The Shore A hardness of Factor II, before and after accelerated artificial weathering, was statistically significant at 0.05 level (P < 0.05). The change in Shore A hardness was greater in the simulated tropical climate group (Group II) as compared to the simulated Mediterranean climate group (Group I) but within clinical limits.

Retention systems for extraoral maxillofacial prosthetic implants: a critical review

We describe the techniques available for retention of implant-supported prostheses: bar-clips, O-rings, and magnets. We present reported preferences and, although this is limited by the heterogeneity of methods used and patients studied, we hope we have identified the best retention systems for maxillofacial prosthetic implants. If practitioners know the advantages and disadvantages of each system, they can choose the most natural and comfortable prosthesis. We searched the PubMed and Scopus databases, and restricted our search to papers published 2001-13. MeSH terms used were Maxillofacial prosthesis and Craniofacial prosthesis OR Craniofacial prostheses. We found a total of 2630 papers, and after duplicates had been removed we analysed the rest and found 25 papers for review. Of these, 12 were excluded because they were case reports or non-systematic reviews. Of the remaining 13, 10 described group analyses and seemed appropriate to find practitioner's choices, as cited in the abstract (n=1611 prostheses). Three papers did not mention the type of prosthetic connection used, so were excluded. The most popular choices for different conditions were analysed, though the sites and retention systems were not specified in all 10 papers. The bar-clip system was the most used in auricular (6/10 papers) and nasal prostheses (4/10). For the orbital region, 6/10 favoured magnets. Non-osseointegrated mechanical or adhesive retention techniques are the least expensive and have no contraindications. When osseointegrated implants are possible, each facial region has a favoured system. The choice of system is influenced by two factors: standard practice and the abilities of the maxillofacial surgeon and maxillofacial prosthetist.

Retention and Mechanical Behavior of Attachment Systems for Implant-Retained Auricular Prostheses

OBJECTIVE

Auricular prostheses are artificial substitutes for facial defects. The retention of these has often been a problem. This study aimed to evaluate the mechanical behavior of 3 retained auricular prosthetic connections when submitted to a mechanical cycling test.

MATERIALS AND METHODS

Twelve samples with installed implants were obtained and divided into 3 groups according to their retention system with 4 samples in each group. I: bar-clip system; II: magnet system; and III: ball/o-ring system. Each of samples was submitted to the pull-out test during 3240 cycles (f = 0.5 Hz) to determine its tensile strength. The mechanical cycling test was performed using the servo-hydraulic machine MTS 810-Flex Test 40 (Eden Prairie, MN) that had a 2.5 mm shift at a 10 mm/s velocity. The retaining strength for each of the samples was obtained at 7 intervals.

RESULTS

The tensile strength for the group retained by the bar-clip system (29.60 N) was higher with statistically significant difference (P < 0.05) when compared with the group retained by the ball/o-ring system (9.41 N) and magnets system (8.61 N) for all periods assessed. The ball/o-ring system showed loss of retention during the fatigue test (Kruskal-Wallis, chi-squared = 17.28; P < 0.01).

CONCLUSIONS

The evaluated systems showed a tensile strength compatible with the clinical use and no fractures of the components were observed.

A systematic comparison of bar-clips versus magnets

STATEMENT OF PROBLEM

Currently, which type of suprastructure is preferred when fabricating implant-retained craniofacial prostheses is unknown.

PURPOSE

The purpose of this systematic review was to identify the best retention system (bar-clips versus magnets) for implant-retained craniofacial prostheses.

MATERIAL AND METHODS

This systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A systematic search of Medline/PubMed and Web of Science databases for clinical trials was conducted on implant-retained craniofacial prostheses published between 2005 and 2015. English-language studies that directly compared different types of retention systems or presented information on implant survival, periimplant soft tissue reactions, and prosthetic complications were included. Nonclinical studies were excluded to eliminate bias.

RESULTS

A total to 173 studies were identified, of which 10 satisfied the inclusion criteria. In total, 492 participants were included in these studies. Four selected studies displayed detailed information with regard to the number of implant failures according to the retention system. As reported, 29 (18.2%) of 159 implants with magnets failed, whereas 25 (31.6%) of 79 implants with bars failed. Overall auricular superstructures showed the highest survival (99.08%). In addition, 55.4% of all participants in the selected studies showed grade 0 of periimplant soft tissue reactions.

CONCLUSIONS

A systematic search for clinical studies resulted in few studies with a short-term follow-up and small number of participants. The limited data collected indicated that magnets show fewer complications than bar superstructures; however, no hard conclusions could be drawn. Further research, preferably in the form of clinical trials, is needed to validate these findings.

Epithetic nasal reconstruction for nasal carcinoma: retrospective analysis on 22 patients

Advanced nasal cancers usually demand partial or total rhinectomy followed by radiotherapy. Reconstruction of the resulting defects can be achieved by means of reconstructive plastic surgery and/or epithetic surgery. The data of 22 patients who had been treated after nasal ablation by means of custom-made silicone nasal epithesis fixed by bone-anchored magnets between 2003 and 2014 were evaluated retrospectively. There were 15 male (68.2 %) and 7 (31.8 %) female patients. The most common etiology that led to epithetic rehabilitation was a squamous cell carcinoma in 16 patients. An operative revision was necessary in two patients due to screw loss. Twenty patients were still alive with no evidence of disease after minimum follow-up of 2 years (90.9 %). Epithetic rehabilitation after nasal ablation to treat nasal malignancies is an interesting alternative to plastic and reconstructive surgery. Bone-anchored fixation using magnets can achieve a stable epithetic fixation after nasal ablation necessitating, in numerous cases, additional adjuvant therapy like radiation.

Surgical preparation of nasal defects to enhance the implant-retained facial prostheses: A case report

BACKGROUND

Skin cancers requiring nasal resection may be surgically reconstructed and/or prosthetically reconstructed. Singular surgical reconstruction may be ideal for smaller defects in which the nasal bone and cartilaginous portions of the nose are maintained, but surgical reconstruction falls short of providing acceptable aesthetic results for more extensive nasal defects. Prosthetic rehabilitation, or a combination of surgical and prosthetic rehabilitation, is more appropriate for larger defects, but prosthesis retention can be challenging when adhesives are required on adjacent mobile and secreting skin.

METHODS

We report 2 cases of patients with extensive nasal defects who were successfully rehabilitated with nasal prostheses. The nasal defects were surgically optimized with immediate preparation of the surgical margins, placement of a split-thickness skin graft (STSG) within the nasal cavities and exposed maxillary sinuses, and immediate placement of osseointegrated implants.

RESULTS

Excellent prosthetic retention can be achieved without the need for adhesives. A skin graft-lined defect has minimal secretions and allows for improved defect cleansing.

CONCLUSION

The success of a nasal prosthesis depends on appropriate surgical management of the defect, and, thus, collaboration between the various surgical and prosthetic teams is essential. © 2016 Wiley Periodicals, Inc. Head Neck 39: E4-E11, 2017.

In Vitro Cytotoxicity of Maxillofacial Silicone Elastomers: Effect of Nano-particles

PURPOSE

Silicone elastomers are generally used for maxillofacial extraoral prostheses. The purpose of this in vitro study was to evaluate the cytotoxicity of different kinds of nanoparticles added to two types of maxillofacial elastomers.

MATERIALS AND METHODS

A-2000 and A-2006 silicone elastomers were used. The silicone specimens were divided into eight groups according to the presence of additional nanoparticles (n = 18). The following represents the groups in the study: Group A: A-2000 silicone (control group); Group B: A-2006 silicone (control group); Group C: A-2000 silicone and the addition of titanium dioxide (TiO₂ ); Group D: A-2006 silicone and the addition of TiO₂ ; Group E: A-2000 silicone and the addition of fumed silica; Group F: A-2006 silicone and the addition of fumed silica; Group G: A-2000 silicone and the addition of silaned silica; Group H: A-2006 silicone and the addition of silaned silica. A paired sample t-test was used to analyze the cytotoxicity of each group after 24, 48, and 72 hours.

RESULTS

Based on the results of the 24-hour analysis, the biocompatibility values of the (A-2006) fumed silica group were higher than those of the control groups. There was no statistically significant difference in A-2006 and A-2000 groups. The cytotoxicity values of the control groups and TiO₂ (A-2000 silicone) elastomer groups increased at all test times; however, the cytotoxicity values of the TiO₂ (A-2006), fumed silica (A-2006), silaned silica (A-2006), fumed silica (A-2000), and silaned silica (A-2000) groups increased significantly only from 24 to 48 hours.

CONCLUSION

Nanoparticles of TiO₂ , fumed silica, and silaned silica added to a commercial silicone-based elastomer used for fabrication of maxillofacial prostheses are nontoxic.

Treatment Outcome of the Transfacial Titanium Epiplating System for Total Nasal Defects

BACKGROUND

Malignant tumors are the most frequent reason for acquired defects of the nose. Bone-anchored craniofacial prostheses represent a secure, uncomplicated, and cosmetically acceptable rehabilitative alternative to surgical reconstruction. The aim of this study was to determine a potential benefit of the Titanium Epiplating System (Fa. Medicon, Tuttlingen, Germany) as a grouped implant system in the anatomically difficult nasal region with limited bone supply.

METHODS

Patients with complete nasal defects who received a transfacial Titanium Epiplating System between January of 2009 and December of 2013 for nasal prostheses were included. The Epiplating titanium plates are specially adapted to the nasal region and were modified individually. Implant survival, periimplantitis, clinical course, and risk factors for implant survival were assessed retrospectively, including univariate statistics.

RESULTS

Fifty-three patients were included in this study. At the time of last follow-up, 51 of 53 Epiplating systems (96.2 percent) were stable in situ. One titanium plate had to be renewed because of a traumatic accident and one plate had to be removed because of disease recurrence. Periimplantitis occurred in 7.5 percent and could be treated successfully by either local or systemic antibiotic therapy without any loss of stability in bone anchorage. Only smoking significantly increased the risk of periimplantitis (p = 0.013), whereas age, irradiation, chemotherapy, and immunosuppression did not influence the outcome of therapy. The median healing time with use of the Titanium Epiplating System was 3.6 ± 2.7 months.

CONCLUSIONS

The Titanium Epiplating System is a safe and uncomplicated system for bone-anchored retention of nasal prostheses. Good aesthetic results can be achieved.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Change in color of a maxillofacial prosthetic silicone elastomer, following investment in molds of different materials

PURPOSE

In the authors' experience, the color of silicone elastomer following polymerization in molds made of gypsum products is slightly different from the color that was matched in the presence of the patient, before the silicone is packed. It is hypothesized that the investing materials and separating media have an effect on the color during the polymerization process of the silicone.

MATERIALS AND METHODS

This study compares and evaluates the change in color of silicone elastomer packed in three commonly used investing materials - Dental stone (white color), dental stone (green color), and die stone (orange color); coated with three different separating media - Alginate-based medium, soap solution and a resin-based die hardening material. Pigmented silicone samples of dimensions 1.5 cm × 2 cm × 0.5 cm were made from the elastomer in the above-mentioned mold materials using combinations of the mentioned separating media. These served as test group samples. Control group samples were made by packing a mix of the same pigmented elastomer in stainless steel molds. The L*, a*, b* values of the test and control group samples were determined using a spectrophotometer. The change in color (Delta E) was calculated between the control and test groups.

RESULTS

The mean L, a, b values for the control group were, 31.8, 26.2, and 36.3, respectively. Average values of change in color (Delta E) for samples packed utilizing alginate-based medium, die hardener, and soap solution, respectively in white dental stone (2.70, 2.74, and 2.88), green dental stone (2.19, 2.23, 2.42), and orange die stone (3.19, 2.72, 2.80) were tabulated.

CONCLUSION

Among the investing materials studied, die stone showed the most color change (3.19), which was statistically significant. Among the separating media, die hardener showed the least color change (2.23). The best combination of an investing material and separating media as per this investigation is a dental stone (green) and alginate-based separating medium.

Lightweight acrylic resin facial prosthesis for maxillofacial defects: a fabrication and retention method

Extraoral maxillofacial rehabilitation for compromised or lost facial anatomy resulting from the surgical eradication of malignancy, trauma, or congenital anomalies is commonly accomplished with a silicone prosthesis. However, with increasing size and weight, a silicone prosthesis can lose retention. This report presents 2 patient treatments to introduce a fabrication and retention method for a lightweight acrylic resin facial prosthesis. The prosthesis was fabricated by bonding an acrylic resin facial shell to a computer-edited facial image printed with iron-on transfers. The completed prosthesis was attached to the skin with medical-grade double-sided adhesive tape, which maintained a tight marginal seal even when in contact with saliva and water. The strong prosthetic retention of the lightweight prosthesis enabled orofacial and speech rehabilitation, which makes it a promising alternative to the conventional silicone prosthesis, especially for the restoration of extensive maxillofacial defects.

Implant-retained finger prosthesis with modified retention system

BACKGROUND

Amputations affect both the physical and the psychological aspects of an individual, causing significant impact on self-esteem. The main causes of finger amputations are work-related accidents with dangerous machinery, road traffic accidents, and animal bites, as well as systemic diseases such as diabetes. This report aims to describe a simple technique for fabrication of implant-retained finger prosthesis with a modified base of the retention system.

CASE DESCRIPTION AND METHODS

The O-Ring retention system was used with a modified hexagon-shaped base and a metallic capsule adapted to the acrylic resin to attach the prosthesis to the implant.

FINDINGS AND OUTCOMES

The prosthesis was made with silicone, and after osseointegration, it was installed without complications, leading to a patient satisfied with the end result and encouraged to return to social life.

CLINICAL RELEVANCE

Restoring self-esteem in the patient and static and functional rehabilitation.

Complex craniofacial reconstruction with prostheses as an alternative method to autogenous reconstruction

Reconstruction of facial organ and tissue losses using autogenous tissue is a permanent and effective method in plastic surgery. However, in cases where the patient's general condition does not allow for surgical reconstruction or where the patient is in need of reconstruction of complex organs such as the eye, nose, or ear, an epithesis can be considered as an alternative to treatment with autogenous tissue. The purpose of this study was to investigate the factors affecting the success rate of facial reconstructions with an externally retained prosthesis in relation to the defect location and radiotherapy treatment. Between September 2004 and October 2008, 11 patients with facial tissue defects who had been treated with an osseointegrated implant system were evaluated. Because 1 patient with a midfacial defect died 3 months after the surgery, this case was excluded, leaving a total of 10 patients for evaluation. Five patients' facial defects were located in the ear, 2 patients had nasal defects, and 3 patients had defects in the midfacial region. The total numbers of implants applied to these regions were 13, 6, and 25, respectively. A total of 44 implants applied were followed for an average period of 52.4 months (between 6 and 77 months). In cases where the reconstruction was considered satisfactory, no infections were observed, and there were no implant losses in the mastoid region. Implant losses were observed in a total of 14 implants (31.8%), 2 of which were in the glabellar region (4.5%), and 12 were in the midfacial region (27.2%). The implant losses were observed between the first and 18th postsurgical months (with an average of 6 months). The remaining implants were sufficient to retain the prostheses. Because of these results, the use of implant-assisted epitheses can be considered a viable alternative in patients whose facial defects cannot be corrected through reconstructive surgery performed with autogenous tissue.

Analysis of the periimplant tissue of craniofacial implants by sulcus fluid flow rate (SFFR)

STATEMENT OF PROBLEM

The tissue surrounding craniofacial implants is prone to inflammation; however, no adequate instrument is currently available to measure this objectively.

PURPOSE

The purpose of this study was to describe the parameters influencing the sulcus fluid flow rate in the extraoral periimplant tissue environment.

MATERIAL AND METHODS

Thirty-four patients with 112 craniofacial implants participated. The sulcus fluid flow rate (SFFR) was measured with standardized paper strips. The influence of cleansing liquids, implant location, presence of purulent exudates, smoking habits, depth of crevice, and previous irradiation on the sulcus fluid flow rate were evaluated with covariate adjusted finite mixture models.

RESULTS

Two latent subgroups of SFFR were identified based on a mixed model. The majority (95.5%) had a mean value of 1.44 mm, and the smaller subgroup (4.5%) had a mean value of 10.4 mm. The SFFR values were increased when purulent exudates were present (regression coefficient 1.41), 95% CI (0.67, 2.16). The depth of the crevice influenced the SFFR per unit depth (regression coefficient 0.37), 95% CI (0.22, 0.53). Additional covariates, such as the implant location, history of smoking, and prior irradiation, had no statistical effect on SFFR.

CONCLUSIONS

SFFR can be measured objectively in the extraoral periimplant tissue.

Frontal bone and modified zygomatic implants for retention of a nasal prosthesis: Surgical planning using a three-dimensional computer software program

Implants integrated into bone have revolutionised the retention of total nasal prostheses. However, it may be difficult to identify available sites for placement of the implant after excision. In addition, it is ideal to minimise wide bony exposure after radiotherapy to avoid compromising the blood supply. In this paper we describe a technique for accurate placement of frontal bone and customised zygomatic implants using a computer-designed and fabricated surgical guide with a minimal access flap.

The potential of cohesive silicone for facial prosthetic use: a material property study and a clinical report

PURPOSE

Prosthetic reconstruction of a facial defect can help to reduce disfigurement and restore the social functioning of the patient. Several methods for holding a prosthesis in place exist, including the use of osseointegrated implants and medical adhesive agents; however, since the treatment options for some patients may be restricted by various health conditions and other limitations, including allergies to adhesive agents, a history of radiation therapy, and financial issues, other options that suit individual demands are required. The objectives of this study were to test the hypothesis that adhesive characteristics could be bestowed on silicone elastomers by altering their catalyst/base silicone ratios (CBR) and to examine the effect of the thickness of the cohesive silicone layer of a prosthesis on its initial adhesive strength.

MATERIALS AND METHODS

The adhesive strengths of specimens with CBRs ranking from 1/10 to 1/70 were examined by the rolling ball tack test. A tensile test was used to evaluate the tensile adhesive strengths of specimens made of layers of cohesive silicone (CBR 1/60) and normal silicone (CBR 1/10) with different thicknesses. Auricular prostheses containing cohesive silicone on the skin side were applied to a 50-year-old man with defects in both auricular regions and with reduced manual dexterity due to serious burns.

RESULTS

The rolling distance was reduced with a decrease in CBR, and a thinner cohesive silicone (CBR 1/60) layer demonstrated a higher peak load. On clinical application, the adhesion of the auricular prosthesis containing cohesive silicone was improved by expanding the adhesive area and altering the thickness of the cohesive silicone layer, resulting in sufficient adhesion and easier handling than that achieved using an adhesive agent 1 year post delivery.

CONCLUSION

These results suggest that cohesive silicone can be used as a glueless retentive material for facial prostheses.

Maxillofacial prosthetic rehabilitation in the UK: a survey of maxillofacial prosthetists' and technologists' attitudes and opinions

Maxillofacial prostheses are constructed by maxillofacial prosthetists and technologists (MPTs), as an alternative treatment when maxillofacial defects cannot be surgically fulfilled. A questionnaire was conducted surveying 220 MPTs working in all UK maxillofacial units about their opinions, attitudes, and experience regarding several aspects related to maxillofacial silicone prostheses. Numbers and percentages of maxillofacial prostheses, their retention method, serviceability, reduced serviceability causes, and digital technologies (DT) used in constructing prostheses were analysed. Thousand hundred and ninety-three prostheses were constructed (42% ocular, 31% auricular, 13% orbital, 12% nasal, 1% composite, more than one facial prosthesis). Adhesives commonly retained orbital (48%) and nasal (45%) prostheses. Implant-retained bars commonly retained auricular prostheses (70%). Ocular prostheses were entirely retained by undercuts. Implant-retained prostheses remained serviceable for twice as long (19-24 months) as adhesive-retained prostheses (7-12 months). Causes for prosthesis replacement included colour changes (71%), poor maintenance (41%), and silicone tear (37%). Thirty-one percent of MPTs used DT computer software and programs for designing and constructing maxillofacial prostheses. In conclusion, adhesives, implant-retained bars and magnets are commonly used retentive methods. Prosthesis failure is caused mainly by colour change, poor maintenance, silicone tear and delamination. Different DTs are used by one-third of MPTs.

Retrospective study of treatment outcomes with implant-retained extraoral prostheses: survival rates and prosthetic complications

STATEMENT OF PROBLEM

Implant-retained extraoral prostheses are an acceptable solution for patients with facial defects. However, these prostheses have a limited service life. Little has been reported on survival periods of implant-retained extraoral prostheses and prosthetic complications of this treatment modality.

PURPOSE

The purpose of this study was to estimate the survival rates of implant-retained extraoral prostheses and to analyze the frequency of prosthetic complications.

MATERIAL AND METHODS

Seventy patients were treated with implant-retained extraoral prostheses. Each patient was examined with respect to the prosthesis appearance and abutment and attachment component complications at 6-month intervals over a period of 10 to 46 months. The Kaplan-Meier survival estimation method was used for the first and subsequent prostheses. The reasons for remaking prostheses were recorded. Complications of the abutment and attachment components and the prostheses were recorded. Frequency of complications was evaluated. Data were analyzed using the Fisher exact test (alpha=.05).

RESULTS

Thirty-two auricular, 25 orbital, and 13 nasal prostheses were evaluated. The Kaplan-Meier analysis revealed an estimated mean survival time of 14.5 months for the patients' first prostheses. The survival times for the first implant-retained auricular, orbital, and nasal prostheses were 14.1, 13.4, and 17.6 months, respectively. The survival times for the second implant-retained auricular, orbital, and nasal prostheses were 14.4, 15.3, and 14.0 months, respectively.

CONCLUSIONS

Implant-retained extraoral prostheses had limited survival rates. The primary reasons for making new prostheses were discoloration, tearing, and mechanical failures of the acrylic resin substructure or retentive elements. Common complications were the need for clip activation, loosening of bar screws and abutments, and loss of attachment between silicone and the acrylic resin substructure. (J Prosthet Dent 2010;103:118-126).

Radiation-induced leiomyosarcoma of the maxillofacial region: facial reconstruction with implant-retained prosthesis

Radiation-induced sarcoma represents an exceptional rarity in the head and neck region. The treatment is surgical excision with negative margins and follow-up. After surgery, reconstruction of the defects can be accomplished either surgically or prosthetically. Implant-retained maxillofacial prostheses may offer an acceptable solution. In this report, a large facial defect resulting from radiation-induced leiomyosarcoma was reconstructed with implant-retained prosthesis. A patient with a large facial defect resulting from tumor surgery presented for reconstructive treatment. The primary tumor was fibrous histiosarcoma. Four years after the patient was treated with surgical resection and subsequent irradiation, leiomyosarcoma was diagnosed in the defect site. Leiomyosarcoma was treated with complete surgical resection, and the defect was reconstructed with implant-retained prosthesis. The patient was evaluated every 6 months. Implants provided secure retention to the prosthesis. The patient was satisfied with the appearance of the prosthesis. At 12 months' examination, functioning implants were successful; however, color fade of the prosthesis was observed. Radiation-induced leiomyosarcoma, which is an uncommon tumor in the head and neck region, was treated by means of large surgical resection. Implant-retained prosthetic rehabilitation of the patient resulted in acceptable functional and cosmetic results, and the patient has resumed social activities.

Solutions for nasal defects

Many studies on defects caused by trauma, infection, cancer, or congenital are reported in the literature; in nasal reconstructions, contradictions and distinct techniques exist that can be argued. Using the literature, we observe these distinct techniques that can be surgery or in surgery to reestablish and to integrate the patient with satisfaction in the society.

Hyperbaric oxygen: therapy for patients with maxillofacial implants?

Osseointegration was an innovative treatment in dentistry during the last 3 decades. The success of osseointegration is related to factors such as material biocompatibility, adequate quality of bone tissue that allows implantation, surgical technique, and macrostructure and microstructure of implant. The osseointegrated implants are successfully applied in dental clinic including oral and facial rehabilitations mainly for patients submitted to mutilating surgeries. However, patients submitted to radiation therapy present risks to treatment with implants owing to adverse effects on bone tissue. Nowadays, the literature suggests different therapies to improve the success of osseointegration such as hyperbaric oxygen therapy that aims to prepare bone and adjacent tissues to receive the implant. Therefore, the purpose of this study was to present a literature review concerning indications, contraindications, successes, and difficulties with hyperbaric oxygen therapy associated to maxillofacial implants.

Survival rates and periimplant soft tissue evaluation of extraoral implants over a mean follow-up period of three years

STATEMENT OF PROBLEM

The use of implants with extraoral prostheses provides excellent support, stability, and retention, thereby offering the potential for improving a patient's appearance and quality of life. However, few studies have examined cumulative survival rates of extraoral implants, nor have these reports documented long-term aspects of treatment, such as soft tissue health around abutments.

PURPOSE

The purpose of this study was to evaluate the survival rates and the periimplant soft tissue responses of extraoral implants used to retain facial prostheses.

MATERIAL AND METHODS

Thirty-three patients with auricular, nasal, and orbital anatomical compromise were treated with 98 craniofacial and dental implants. Of the 33 patients, 14 had auricular, 9 had nasal, and 10 had orbital defects. After a 3-month osseointegration period, implant-retained prostheses were fabricated. Following completion of treatment, each patient was seen at 6-month intervals. These examinations were recorded for this patient cohort from 25 to 50 months. Data were analyzed using Kaplan-Meier survival analysis. A 5-point scale was used to record the health of periimplant soft tissues. The unit of measure as a visit/site unit was assigned for each instance and implant site. Periimplant soft tissue reactions were assessed for auricular, nasal, and orbital defects, for each implant site used for these patients' treatments.

RESULTS

The overall cumulative survival rates were 100% for auricular, 83.3% for nasal, and 77.4% for orbital implants, respectively. The survival rates of the implants were 72.7% for those placed in irradiated sites treated without adjunctive HBO therapy, and 93.4% for implants placed in nonirradiated sites. To evaluate the response of the periimplant soft tissues to the implants, a total of 524 visits/sites were recorded. Absence of inflammation (grade 0) of the periabutment soft tissues was observed in 73.3% of the visits/sites.

CONCLUSIONS

The anatomical site into which the implant is placed has an effect on success rate. The auricular site is the most predictable implant site. Survival rates of nasal and orbital implants were found to offer promising results in achieving reliable implant prognoses in these regions. Regardless of the implant site, a decreased survival rate was observed in the irradiated sites. Periimplant soft tissue reactions were most commonly associated with lapses in hygiene.

Effects of radiation therapy on craniofacial and dental implants: a review of the literature

OBJECTIVES

The theories of the effects of radiation therapy on craniofacial and dental implants have been challenged by new models. Animal and clinical studies differ on the importance of dose effect and implant location regarding implant survival. Our purpose was to explore the risks of irradiation regarding dose levels, timing of radiation, implant location, and material.

STUDY DESIGN

A systematic search of the literature was performed to identify studies reporting animal and human data on the success of implants in irradiated versus nonirradiated bone.

RESULTS

Eleven animal studies exploring histomorphometric, biomechanical, and histologic features of implants in irradiated bone were summarized. Sixteen human clinical studies evaluating craniofacial (n = 8) and dental (n = 8) implants in irradiated bone were summarized. No meta-analyses of dental implants in irradiated bone were found. Efficacy studies comparing different implant types in irradiated bone were not found.

CONCLUSION

Studies from both animal subjects and human patients indicate that irradiated bone has a greater risk of implant failure than nonirradiated bone. This increase in risk may be up to 12 times greater; however, studies making these comparisons are of poor to moderate quality, so the magnitude of this difference should be accepted with caution.

Implant-retained digital prostheses with custom-designed attachments: a clinical report

A patient with traumatic amputation of 4 digits was rehabilitated with implant-supported digital prostheses. Implants were placed in the residual bone structure of the thumb, index, middle, and ring fingers. After osseointegration was complete, custom-designed retentive attachments and silicone digital prostheses were fabricated to restore the natural appearance of the hand, and some degree of tactile sensation was also achieved.