International Expert-Based Consensus Definition, Staging Criteria, and Minimum Data Elements for Osteoradionecrosis of the Jaw: An Inter-Disciplinary Modified Delphi Study

Purpose

Osteoradionecrosis of the jaw (ORNJ) is a severe iatrogenic disease characterized by bone death after radiation therapy (RT) to the head and neck. With over 9 published definitions and at least 16 diagnostic/staging systems, the true incidence and severity of ORNJ are obscured by lack of a standard for disease definition and severity assessment, leading to inaccurate estimation of incidence, reporting ambiguity, and likely under-diagnosis worldwide. This study aimed to achieve consensus on an explicit definition and phenotype of ORNJ and related precursor states through data standardization to facilitate effective diagnosis, monitoring, and multidisciplinary management of ORNJ.

Methods

The ORAL Consortium comprised 69 international experts, including representatives from medical, surgical, radiation oncology, and oral/dental disciplines. Using a web-based modified Delphi technique, panelists classified descriptive cases using existing staging systems, reviewed systems for feature extraction and specification, and iteratively classified cases based on clinical/imaging feature combinations.

Results

The Consortium ORNJ definition was developed in alignment with SNOMED-CT terminology and recent ISOO-MASCC-ASCO guideline recommendations. Case review using existing ORNJ staging systems showed high rates of inability to classify (up to 76%). Ten consensus statements and nine minimum data elements (MDEs) were outlined for prospective collection and classification of precursor/ORNJ stages.

Conclusion

This study provides an international, consensus-based definition and MDE foundation for standardized ORNJ reporting in cancer survivors treated with RT. Head and neck surgeons, radiation, surgical, medical oncologists, and dental specialists should adopt MDEs to enable scalable health information exchange and analytics. Work is underway to develop both a human- and machine-readable knowledge representation for ORNJ (i.e., ontology) and multidisciplinary resources for dissemination to improve ORNJ reporting in academic and community practice settings.

Effect of Thixotropic Agent on the Color Stability of Platinum-Based Silicone Maxillofacial Elastomers after Artificial Aging

Maxillofacial prostheses are essential for restoring natural appearance and function in individuals with defects in the head and neck regions. Thixotropic agents, as liquid additives, are known to increase the viscosity of silicone elastomers. However, color deterioration remains a challenge in facial prostheses, leading to the need for refabrication. Despite this, there is limited research on the effect of thixotropic agents on the color stability of silicone maxillofacial elastomers. This study aims to investigate the impact of different thixotropic agent amounts on the color degradation of various maxillofacial silicone elastomers. Three elastomers (A-2000, A-2006, and A-2186) were combined with five pigments (no pigment as control, red, yellow, blue, and a mixture of red, yellow, and blue), and mixed with six thixotropic agent quantities (0, 1, 2, 3, 4, and 5 drops). A total of 450 specimens were fabricated (n = 5) and aged in an artificial aging chamber. L*, a*, b* readings were obtained before and after aging using a digital spectrophotometer. Color difference (ΔE*) means and standard deviations for 150 kj/m2, 300 kj/m2, and 450 kj/m2 were calculated. Statistical analyses, including four-way ANOVA and Fisher's PLSD test, were conducted to determine any significant differences (p < 0.05) among the groups. A comprehensive analysis revealed significant four-way interactions among the groups. In the mixed-pigmentation group, adding 4 drops of thixotropic agent resulted in ΔE* above 3 only in A-2186 silicone at 300 and 450 kj/m2 energy levels. However, the color stability of mixed-pigmented A-2000 and A-2006 remained within the acceptable thresholds of 3 ΔE* at all irradiance levels in this study. At each energy level, A-2006 exhibited the highest color stability with an increasing thixotropic agent quantity among all the silicones. Conversely, A-2186 was more affected by the increased number of thixotropic agent drops in each pigmentation group, including the control group at 450 kj/m2. The quantity of thixotropic agent plays a crucial role in determining the color stability of different silicone elastomers pigmented with various intrinsic pigments. The thixotropic agent amount has a more significant impact on color stability than the type of pigment used in the silicone elastomers. A key overarching insight from this investigation is the identification of a safety threshold for the thixotropic agent quantity of 3 drops for each silicone type, pigmentation, and energy level. These findings highlight the importance of considering the proper combination of thixotropic agents, pigments, and silicone materials to achieve optimal color stability in maxillofacial prosthetic applications.

Survey of currently selected dental implants and restorations by prosthodontists

PURPOSE

The purpose of this study was to survey the prosthodontists of the American College of Prosthodontists (ACP) and the American Academy of Maxillofacial Prosthetics (AAMP) to identify the most commonly used implant both during their training and currently in practice, and to evaluate overall restorative preference. Participants were asked to rank criteria that make an implant company desirable and important features when selecting an implant.

MATERIALS AND METHODS

An electronic survey was emailed to 1,739 members of the ACP and AAMP.

RESULTS

The majority of respondents (79%) were trained using Nobel Biocare brand implants, which was also the brand most often selected by participants for use in all regions of the oral cavity (34% to 39%, location dependent). Abutment preferences varied by area: incisors and canines (29%) and highly esthetic areas (53%) were more likely to be restored with custom milled zirconia abutments, while prefabricated titanium abutments were preferred for premolars and molar areas. Conventional loading was most often applied, ranging from 95% in medically compromised patients to 55% in esthetic areas. The majority of participants (86%) used Locator attachments for complete overdenture restorations. Also, respondents selected an implant company based on features and literature support versus cost and customer service. The implant features deemed most important were the design of the internal connection and ease of finding replacement parts; thread design and variety of abutments were deemed least important. Respondents reported that while implant planning software was used, they rarely/never order the concurrent surgical guide.

CONCLUSION

Within the study's limitations, the majority of prosthodontists select implants based on training, features, and literature support.

Evaluating postdoctoral dental candidates: assessing the need and recommendations for a national qualifying examination

Increasingly, U.S. dental schools report pass/fail grades and do not rank students. In addition, the Joint Commission on National Dental Examinations will report National Board Dental Examination (NBDE) scores as pass/fail after January 1, 2012. This article discusses how these changes will force postdoctoral dental program directors to modify how they assess candidates and how noncognitive evaluations might enhance those assessments. The authors propose developing a national qualifying examination for postdoctoral dental programs that will measure knowledge, decision making, and noncognitive traits including empathy, self-confidence, integrity, and emotional intelligence. Without NBDE scores, class rank, and GPA as a basis for decision making, a single national qualifying examination would assist postdoctoral programs in selecting high-quality candidates based on knowledge, critical thinking skills, and noncognitive traits.

Clinical trial of chlorinated polyethylene for facial prosthetics

PURPOSE

Extraoral maxillofacial prostheses have been fabricated with silicone elastomer for 50 years with few improvements. The objective of this controlled, randomized, prospective, double-blind, single-crossover, multicenter, phase III clinical trial was to determine the noninferiority of chlorinated polyethylene elastomer (CPE) to silicone elastomer for fabricating prostheses.

MATERIALS AND METHODS

Forty-two patients were randomly assigned to wear a custom-made prosthesis fabricated from both materials for 4 months and asked to rate their satisfaction (0 = not satisfied, 10 = completely satisfied). Many other measures of prosthesis performance were investigated (see online appendices).

RESULTS

Of the 28 patients who completed the study, 68% had used silicone prostheses previously. Overall, patients rated the silicone prosthesis higher than CPE (difference: 2.2, 95% confidence interval [CI]: 0.9 to 3.6, P = .017). Previous users had a stronger preference for silicone (difference: 3.3, 95% CI: 1.7 to 4.9, P = .001), while the 9 new users rated the two materials similarly (difference: 0.0, 95% CI: -2.1 to 2.1, P = 1.00).

CONCLUSIONS

The noninferiority of CPE could not be established because of the early termination of the trial. Previous users of silicone prostheses preferred those made of silicone. However, new users expressed no preference between prostheses fabricated with the low-cost CPE or silicone. The authors have developed original clinical trial methodology for assessing extraoral maxillofacial prostheses.

Influence of pigments and opacifiers on color stability of silicone maxillofacial elastomer

OBJECTIVES

To determine the effects of opacifiers and silicone pigments on the color stability of silicone A-2000 maxillofacial prosthetic elastomers subjected to artificial aging.

METHODS

Seventy-five groups (n=5) were made by various combinations (5%, 10%, and 15%) of four dry earth opacifiers (Georgia kaolin, Gk; calcined kaolin, Ck; Artskin white, Aw; titanium white dry pigment, Td); and 1 silicone pigment white (Sw) with one of 5 silicone pigments (no pigment (control), red (Pr), yellow (Py), burnt sienna (Po), and a mixture of Pr+Py+Po). A reflection spectrophotometer was used for color measurements. Color differences (DeltaE*) between baseline and after an energy exposure of 450kJ/m(2) in an artificial aging chamber were calculated. A DeltaE*=3.0 was used as 50:50% acceptability threshold in result interpretation, while DeltaE*=1.1 was used as 50:50% perceptibility threshold. Means were compared by Fisher's PLSD intervals at the 0.05 level of significance. Color differences after aging were subjected to three-way analysis of variance.

RESULTS

Yellow ochre mixed with all opacifiers at all intervals had increased DeltaE* values significantly from 0.7-2.1 up to 3.8-10.3. When mixed groups were considered, at 5%, Gk exhibited the smallest color changes, followed by Td<Aw=Sw<Ck, respectively. At 10%, Aw<Td<Gk<Sw=Ck. At 15%, Td<Aw<Gk=Sw<Ck (< indicates p<0.0001 and = indicates p>0.05). The smallest color differences, observed for opacifier groups, were recorded for Gk at 5%, and Td and Aw at 10% and 15%. Overall, 15% Td exhibited the smallest, whereas 5% Ck exhibited the most pronounced color change after artificial aging. All DeltaE* values were below the 50:50% acceptability threshold, indicating acceptable color stability. Color differences for 10% and 15% of Aw and Td were below 50:50% perceptibility thresholds, indicating excellent color stability.

CONCLUSION

Silicone pigments mixed with 10% and 15% Artskin white and titanium white dry pigment opacifiers protected silicone A-2000 from color degradation over time. Yellow silicone pigment significantly affected color stability of all opacifiers especially silicone pigment white and calcined kaolin.

Microleakage of All-ceramic Crowns Using Self-etching Resin Luting Agents

Among the self-adhesive resin cements, Panavia F 2.0 demonstrated less microleakage than RelyX Unicem or Multilink, whether or not a die spacer technique was used.

Facial prosthetic rehabilitation: preprosthetic surgical techniques and biomaterials

PURPOSE OF REVIEW

Attention to detail ensuring a successful facial prosthetic rehabilitation must be considered a priority at the time of presurgery, surgery, and at every stage in fabricating the prosthesis. Teamwork between the surgeon and maxillofacial prosthodontist will ensure an optimal surgical preparation and definitive prosthesis.

RECENT FINDINGS

Evidence of interaction between team members can most certainly be encouraging to the patient. During the prosthetic phase of treatment, focusing on tissue assessment, impression making, sculpting, mold fabrication, familiarity with materials, appreciation of color, delivery of instructions, and patient education will ensure a satisfactory outcome. With the desire, determination, and encouragement from the restorative team to make the most of this artificial replacement, a patient can have a higher quality of life and a more normalized lifestyle.

SUMMARY

This review presents current concepts regarding facial prosthetic rehabilitation of patients with head and neck cancer and facial prosthetic biomaterials.

Color Stability of Dry Earth Pigmented Maxillofacial Silicone A-2186 Subjected to Microwave Energy Exposure

PURPOSE

The purpose of this study was to measure spectrophotometrically the color stability of pigmented A-2186 silicone maxillofacial elastomer with 10% by volume of titanium white dry earth opacifier before and after exposure to microwave energy over a simulated 1.5-year period of microwave sterilization.

MATERIALS AND METHODS

A-2186 silicone elastomer opacified with titanium white dry earth pigment, pigmented with 5 cosmetic dry earth pigment colors [no pigment (control) group (Pc), red (Pr), yellow ochre (Py), burnt sienna (Po), and a mixture of Pr + Py + Po color group (P3)], was used in this study. Each of the 5 experimental groups consisted of 5 specimens. All specimens were placed in a 250 ml glass beaker filled with 150 ml of water (replenished for each microwave exposure). An exposure of 6 minutes was used 18 times (simulating 1.5 years of microwave sterilization with one 6 minute exposure monthly). Reflectance values were measured by spectrophotometer. Three- and two-way analyses of variance with repeated measures were performed for the color difference (DeltaE*) with the factors of group/color/months, and group/months, respectively. Means were compared by Tukey Honest Significant Difference (HSD) multiple range test calculated at the 0.05 level of significance using SPSS.

RESULTS

The trained human eye can detect color changes (DeltaE*) greater than 1.0. Most DeltaE* values of the red pigment group at all intervals and the mixed pigment group at 15- and 18- month intervals increased significantly greater than 1.0 (p < 0.001) compared with the control group. Yellow and burnt sienna groups remained the most color stable over time with DeltaE* values below 0.35.

CONCLUSIONS

Lack of color stability of red dry earth pigmented A-2186 silicone maxillofacial elastomers was clinically significant after 12-month exposure to microwave energy as compared with yellow, burnt sienna, and opacified A-2186 dry earth pigments.

The functional and esthetic deficit replaced with an acrylic resin gingival veneer

Periodontal attachment loss in the maxillary anterior region can often lead to esthetic and functional clinical problems including disproportional and elongated clinical crowns, visible interdental embrasures, and altered linguoalveolar-labiodental consonant production. Assuming fixed prosthetic reconstructions will be chosen to treat these areas, it becomes a hygienic compromise to fill these areas in with porcelain. In the presence of these problems, an acrylic resin gingival veneer is an easily constructed, inexpensive, and practical device to optimize the esthetic and functional outcome in these special situations while permitting cleansibility of the prosthesis and supporting tissues. This article presents a step-by-step technique for the fabrication of a gingival veneer.

Technique for fabricating a lightweight, urethane-lined silicone orbital prosthesis

A technique is presented for packing an acrylic resin core and controlling the thickness of an orbital prosthesis with the use of an irreversible hydrocolloid matrix. This technique provides a durable core without damaging the orbital prosthesis mold and permits a controllable thickness and therefore a lighter prosthesis.

Effect of adhesive retention on maxillofacial prostheses. Part I: skin dressings and solvent removers

STATEMENT OF PROBLEM

The success of most maxillofacial prostheses depends on retention by medical adhesives. Products such as Smith-Nephew's Skin-Prep (SP) are available that can be used on the skin that could improve prosthesis adhesion protective dressing. The removal of adhesive from the skin is also problematic, so solvents, such as Uni-Solve adhesive remover (US), are often used.

PURPOSE

This study measured the removal force of silicone elastomer strips with 2 adhesives from the skin of human subjects during the day, as affected by the use of SP and US, and determined the site of adhesive failure.

MATERIAL AND METHODS

Silicone rubber strips were applied in a predetermined random order to the ventral arm surfaces of 20 human subjects. US was applied to half the sites 1 day before testing. SP was also applied to half the sites just before Epithane-3 (E3) or Secure(2) Medical Adhesive (SMA) were used to adhere the strips. They were peeled from the skin 6 hours later in an Instron at a rate of 10 cm/min.

RESULTS

A 3-way within-group MANOVA revealed significant differences without interactions between adhesives (SMA=96.3 N.m, E3=24.1 N.m; P<.0005) and between use or nonuse of SP (SP=65.8 N.m, no SP=54.6 N.m; P<.0005). The use of US was not significant (no US=61.8 N.m, with US=58.6 N.m; P=.197). SMA adhered to the prostheses, whereas E3 adhered to the skin, leaving a residue (Fisher exact test; P<.0003).

CONCLUSION

The combination of SMA and SP showed the highest adhesive bond strength. Overall, SMA was 3 to 5 times more retentive than E3. SP improved adhesion of both SMA (15%) and E3 (27%). SMA was still far more retentive. US had no effect on retention. SMA remained on the prostheses, whereas E3 left a difficult-to-remove residue on the skin.

A combined direct dowel and indirect core technique

The dowel-and-core restoration is indicated when inadequate tooth structure remains to retain an extracoronal restoration. A modified technique for fabricating the dowel and core combines the direct technique of forming the dowel in the actual channel with the indirect technique of creating an ideal core contour in the laboratory. This technique allows the operator to create an accurate and passive fit of the dowel pattern in the canal preparation. The technique also introduces the option of retrieving the dowel portion by utilizing a polyvinyl siloxane cast or liner. Further advantages of the technique are reduced chairside time and the ability to capitalize on the preparation of multiple teeth. The technique focuses efforts on achieving an accurate and passive fit of the dowel clinically while delegating the formation of the core to the laboratory.

Simplified methods for fabricating tissue-supported implant-retained overdentures with retention from a resilient liner

Resilient denture liner materials can be useful for tissue-supported implant-retained overdentures. They allow physiologic movement of the denture toward the tissues. This article presents a technique that offers several advantages over other methods of fabricating the overdenture with a resilient liner, and of transferring the superstructure: the acrylic resin base and the heat-cured resilient liner material are cured simultaneously; superstructure blockout is performed in the laboratory instead of in the mouth, where blockout is difficult; and direct transfer of the superstructure bar is more accurate and eliminates possible fracture of the duplicated superstructure if formed in die stone.