The Reproducibility and Applicability of an EFD(®) Dispenser in the Prosthetic Technology of Maxillofacial Prostheses.

A reproducible method of dosing pigments can be beneficial and more efficient in the current colour matching procedure in maxillofacial prosthetics. In this study the reproducibility and applicability for pigment dosing of a commercial available EFD(®) dispenser were tested. The reproducibility of a Performus™ II type EFD(®) dispenser was tested by repeating dosing experiments with a set of eight syringes filled with pigment pastes (Factor 2; Flagstaff, USA). To evaluate conventional colour matching, four conventionally colour matched samples were polymerized and compared to the original ones. To investigate the reproducibility of the dispenser in practice, a fifth recipe was dispensed 10 times and colour differences were evaluated visually and as well calculated from measurements with a colour and translucency meter (CTM, PBSensortechnology bv). All dispensed amounts of pigment pastes showed a coefficient of variation in weight of less than 10 %. Evaluating the reproductions of four skin batches compared to the original batches, a ∆E2000 colour difference of 3-7 was measured. Evaluating ten reproductions of one skin coloured batch made with the dispenser, color difference ∆E2000 values compared to the average L*a*b* values, were less than 2 and no visual colour differences could be estimated. Conform these results, low colour differences could be measured with the CTM, indicating no visually observable consequences. Despite the estimated coefficient of variation, the reproducibility of the EFD(®) dispenser in terms of colour difference ∆E2000 of successive dispensing is applicable for colour reproduction in facial prosthetics. Segregation of the current color pastes in due time needs to be taken into consideration.

Variation in repeated mouth-opening measurements in head and neck cancer patients with and without trismus.

Trismus after head and neck cancer treatment may severely limit mandibular functioning. Interventions aimed at reducing trismus can only be evaluated when the amount of variation associated with these measurements is known. The aim of this study was to analyse the variation in mouth-opening measurements in patients treated for head and neck cancer, with and without trismus. Maximal mouth opening was measured in 120 patients in two sessions of three repeated measurements by one observer. To analyse the influence of interobserver variation on mouth-opening measurements a subgroup of 30 patients was measured by a second observer. The standard deviation of the six measurements per patient was used as the variation in measurements of maximal mouth opening. No significant difference was found in maximal mouth opening in patients with (n=33) or without (n=87) trismus. The interobserver intraclass correlation coefficient (ICC) was 0.98. Intraobserver ICC and intersession ICC reliabilities both were 0.99. The variation in the mean values of the three measurements was only slightly smaller than the variation of the single measurements. Variation in maximal mouth opening in patients with trismus does not differ from variation in maximal mouth opening in patients without trismus. Interobserver variation is limited.

[Dissertations 25 year after date 18. Skin colour and facial prosthesis]. / Proefschriften 25 jaar na dato 18. De kleur van aangezichtsprothesen.

The traditional 'trial and error' methods for skin colour recording are not satisfactory. In 1982 a dissertation was published, titled 'Skin colour and facial prosthetics, a colorimetric study'. The dissertation was concerned with a clinical study of skin colour recording objectively in a random sample of 100 people, using subtraction colorimetry. Subsequently, facial prostheses were fabricated for a group of patients with a facial defect who had to undergo radiotherapy. From the results of the study the 3 following conclusions were drawn. Skin colour recording for producing a facial prosthesis need to be carried as close to the facial defect as possible. Alterations of skin colour are determined by light scattering in the skin as well as skin pigments. In patients with facial defects who have to undergo adjuvant radiotherapy, skin colour alterations are present until on average 13-14 weeks after completion of the radiotherapy and from that time point the skin colour remains rather stable. After publication of the dissertation, other research results demonstrated that light scattering in the skin, a sign of skin translucency, may be determined with a fiberoptic scattering meter (volume reflectometer). Using the fiberoptic scattering meter, a colour formula can be made, which by calculation shows the amount of pigments and scattering objects needed to produce the correct translucency and colour of a facial prosthesis. Currently, a small beam reflectometer is used for this purpose.

[Post-academic dental specialties 16. Post-academic specialization in maxillofacial prosthodontics]. / Beroepsdifferentiatie in de tandheelkunde 16. Opleiding tot tandarts-maxillofaciale prothetiek.

Maxillofacial prosthodontics is a specialization in dental health practiced in centers for special dental care in The Netherlands by a limited number of dentists and technicians. The necessary skills, which are largely unique in the field of dentistry, were described in 2001 in a training program by the Dutch Association for Gnathology and Prosthodontics. Multidisciplinary diagnostics, treatment planning, and care delivery are taught in a modular system. A shortage of maxillofacial prosthodontists and maxillofacial technicians calls for a structural training of young colleagues.

[Post-academic dental specialties 17. Implant-retained craniofacial prostheses]. / Beroepsdifferentiatie in de tandheelkunde 17. Implantaatgedragen aangezichtsprothesen.

The surgical and prosthetic aftercare of craniofacial prostheses supported by endosseous implants were registered in patients treated with implant-retained craniofacial prostheses in a university clinic during the last two decades. Aftercare was registered during the period from implant placement until the last follow-up visit. Implant survival rate was 95.2% in non-irradiated and 78.8% in irradiated bone. Discoloration of the silicon material, becoming loose of the acrylic clip carrier from the silicone, rupture of the silicone, and ill-fitting of the prosthesis were main reasons for fabrication of a new craniofacial prosthesis.

Satisfaction with treatment outcome in bilateral cleft lip and palate patients.

The aim of this case-controlled study was to assess satisfaction with facial appearance and function, and health-related quality of life (HRQL) in bilateral cleft lip and palate patients (BCLP). The study sample was composed of adult BCLP subjects and controls matched for age, gender and socioeconomic status. Outcome measures included a self-administered questionnaire evaluating satisfaction with facial appearance, function and HRQL. Bivariate statistics were computed to analyse the association between BCLP status and outcome measures. Forty-three treated adult BCLP patients (mean age 28.2 years, SD 7.8) were compared to 43 controls without clefts (mean age 28.5 years, SD 8.0). Quantitative and qualitative assessment revealed that BCLP patients were significantly less satisfied with the appearance of the upper lip, the nose and nasal breathing. Additionally, satisfaction with facial appearance correlated positively with HRQL. For speech, hearing and drinking, quantitative scores did not differ between BCLP and controls, while qualitative assessment revealed that BCLP patients had considerable problems and concerns with these functions. This study underlines the importance of qualitative assessment of patient satisfaction with treatment outcome to identify individual problems and concerns not revealed by quantitative measures alone.

[Oligodontia: treatment plan and therapy]. / Oligodontie: Opstelling en uitvoering van behandelplannen.

The aim of this retrospective study was to gain insight in treatment planning and therapy for patients with oligodontia. Records of 58 treated patients with oligodontia were screened using several parameters: gender, year and age of registration, symptoms, case history, treatment plan and therapy. Treatment plans were sorted into the following categories: tooth-supported overdentures, fixed or removable partial dentures and implant-supported restorations. Dependent on the complexity of oligodontia, it is advocated to make a treatment plan before the age of 12 years old and to follow the provided treatment conscientiously until the final prosthetic treatment. After analyzing the 58 treatment plans, the following conclusions could be made: the treatment plan was not in all cases made before the age of 12 years, it was not clear in all cases who was the coordinator of the treatment and dental implants are becoming more and more important in treating patients with oligodontia.

[Dental treatment anxiety. A review of useful anxiety-measuring instruments]. / Angst voor tandheelkundige behandelingen. Een overzicht van de bruikbare meetinstrumenten.

Dental anxiety is a common problem. Different tests have been developed to measure the nature and the severity of dental anxiety or phobia. These tests can help to identify highly anxious patients who need special dental care. In this article, the dental anxiety tests useful in The Netherlands are reviewed.

Five years of aftercare of implant-retained mandibular overdentures and conventional dentures.

The purpose of this multicentre randomized clinical trial was to analyse surgical and prosthetic aftercare and clinical implant performance of edentulous patients with implant-retained mandibular overdentures and of patients with conventional dentures, either or not after pre-prosthetic vestibuloplasty and deepening of the floor of the mouth. The evaluation period was 5 years. The implant systems evaluated were the IMZ implant system, the Brånemark implant system and the Transmandibular Implant system. The centre in Groningen had five groups (n=149) and the centre in Nijmegen had three groups (n=86). The evaluation comprised of surgical and prosthetic aftercare, together with clinical implant performance (CIP). The highest implant loss (29%) is found in the Transmandibular Implant group. All groups had prosthetic revisions and complications according to the CIP-scale. The majority of the patients in the endosseous implant groups were subject to minor complications. The CIP-score of the Transmandibular Implant group is significantly higher than the scores of the other groups, because of the high number of lost posts. In 26;1% of the patients in this group score 4 is given, which means failure of the implant system. From this study it can be concluded that the endosseous implant systems used in this study have less surgical aftercare and a better clinical implant performance than the Transmandibular Implant system and are therefore the systems of choice for the edentulous mandible.

Treatment outcome of bone-anchored craniofacial prostheses after tumor surgery.

BACKGROUND: Percutaneous endosseous implants have acquired an important place in the prosthetic rehabilitation of patients with craniofacial defects. The objective of this study was to evaluate the clinical outcome of the use of endosseous implants in the orbital and auricular region as well as to assess the satisfaction of patients with implant-retained craniofacial prostheses after tumor surgery. METHODS: The clinical outcome and patient satisfaction of implant-retained prostheses in the auricular and orbital region were evaluated in a group of 26 patients with facial defects after tumor surgery by using standardized questionnaires and a clinical assessment. Twelve patients (n = 31 implants) received the implants during ablative tumor surgery, from which 7 patients (n = 20 implants) were treated with radiation therapy after surgery (mean, 65 grays [Gy]). Fourteen patients (n = 44 implants) received the implants after the tumor surgery, from which 5 patients (n = 21 implants) were irradiated after ablative surgery (mean, 54.4 Gy), but before implant placement. RESULTS: No implants were lost in patients who had not undergone irradiation (100%), whereas 5 implants were lost in the irradiated group (87.8%). The overall implant survival rate was 93.3%. The peri-implant tissues had a healthy appearance, and no cases of osteoradionecrosis occurred. When compared with patients treated with conventional adhesive retained facial prostheses, satisfaction was higher in patients treated with implant-retained facial prostheses. CONCLUSIONS: From this study, it is concluded that implant-retained facial prostheses are better tolerated than adhesive retained prostheses and offer an improvement in the quality of life. Radiotherapy is not a contraindication for the use of osseointegrated implants in the maxillofacial region, but the loss of implants is higher than in nonirradiated sites.

Effectiveness of three treatment modalities for the edentulous mandible. A five-year randomized clinical trial.

Currently, 3 treatment options are available for patients with denture complaints and an edentulous mandible with a height of at least 15 mm: meticulous construction of a new set of dentures (CD), construction of a new set of dentures following preprosthetic surgery to enlarge the denture-bearing area (PPS), and construction of an implant-retained mandibular overdenture (IRO). The aim of this study was to evaluate patient satisfaction and subjective chewing ability of edentulous patients treated with one of these treatment modalities. Ninety edentulous patients (Cawood class IV and V, mean mandibular height 20.7 mm) were randomly assigned to receive 1 of these 3 groups. Denture satisfaction and chewing ability were assessed using questionnaires focusing on denture-related complaints and problems chewing different types of food were assessed before treatment, and 1- and 5-years after treatment. At the 1-year evaluation, significantly better scores were observed in the 2 surgical groups (IRO, PPS) than in the CD group. At 5-year evaluation the "complaints of the lower denture" showed a significantly better score in the IRO group when compared to the PPS and CD groups. No significant differences were observed between the PPS and CD group. From this study it is concluded that both in the short and long term denture satisfaction appears most favourable in the IRO group when compared to the PPS and CD groups. Implant-retained overdentures are therefore a satisfactory treatment modality for edentulous patients with problems with their lower denture, even in cases of not severely resorbed mandibles.

A controlled clinical trial of implant-retained mandibular overdentures; five-years' results of clinical aspects and aftercare of IMZ implants and Brånemark implants.

The aim of this prospective randomized controlled clinical trial was to evaluate a set of clinical items and prosthetic aftercare of edentulous patients with a mandibular overdenture retained by 2 IMZ implants or 2 Brånemark implants during a 5-years' period. Patients were allocated to the IMZ group (n = 29) or the Brånemark group (n = 32) by a computerized balancing method. In the IMZ group 4 implants were lost during the 5-years' follow-up (survival rate: 93%). In the Brånemark group 9 implants were lost (survival rate: 86%). All patients were re-operated successfully. Multiple prosthetic revisions were necessary in both groups, especially the precision attachment system in the overdenture was subject to frequent fracture or loosening. From this study can be concluded that there is no difference in clinical state, radiographical state, survival rate and clinical implant performance between the IMZ implant system and the Brånemark implant system supporting an overdenture on 2 implants after 5 years of follow-up.

Implant-retained mandibular overdentures compared with complete dentures; a 5-years' follow-up study of clinical aspects and patient satisfaction.

The aim of this prospective randomized controlled clinical trial was to evaluate and compare clinical aspects and satisfaction during the first year following treatment and consecutively the change in treatment during the next 4 years of follow-up. Patients were allocated to one of the following treatment modalities: an implant-retained overdenture (IRO-group, 2 endosseous implants, n = 61) or a complete denture (CD-group, n = 60). One year after placement of the denture, unsatisfied patients of the CD-group got the opportunity for a retreatment including an implant-retained overdenture. In the IRO-group 4 implants were lost during the first year and again 4 implants were lost during the next 4 years (survival rate: 93%). All patients could be re-operated successfully. In the CD-group 14 patients (23%) chose an implant-retained overdenture after 1 year. Patients of the IRO-group were significantly more satisfied than patients of the CD-group after 1 year (satisfaction score 8.3 versus 6.6, scale 1-10) and after 5 years (7.4 versus 6.4). From this study it can be concluded that endosseous implants have a high survival rate after 5-years' follow-up. Satisfaction score of the IRO-group is diminishing in time, probably because patients get used to an improved situation. After 5 years, the mean satisfaction score of the CD-group (including patients who got implants) was still lower than of the IRO-group, in spite of the opportunity to a retreatment and have implant-retained overdentures.

Bone grafting of cleft lip and palate patients for placement of endosseous implants.

OBJECTIVE: Fixation of a prosthesis or single tooth replacement using osseointegrated implants has the potential to overcome functional and psychological inconveniences that many patients experience from such appliances. However, the dimensions of the recipient site are relatively often inadequate for implant placement. This study assessed grafting of this site with autogenous bone as a solution for the latter problem. METHODS: Ten cleft lip and palate patients had bone grafts; six had iliac crest grafts to the maxillary sinus floor (31 implants), and four had chin bone grafts to the local defect in the anterior maxilla (six implants). Implants were inserted during the grafting procedure (one patient) or after 3 months (nine patients). RESULTS: No inflammation of the bone grafts or the maxillary sinus occurred. One implant was lost during the healing phase. Four single tooth restorations, one fixed bridge, and five implant-supported overdentures were made. During the follow-up, which was 47 months (range, 28 to 65 months) in the anterior maxilla group and 56 months (range, 28 to 68 months) in the posterior maxilla group, no loss of implants was observed, and all prosthetic appliances functioned well. CONCLUSIONS: It is concluded that bone grafting followed by placement of dental implants can serve as a reliable alternative for conventional prosthetic rehabilitation of cleft patients.

Mandibular overdentures supported by two or four endosteal implants. A prospective, comparative study.

The aim of this prospective study was to evaluate the effect of the number of implants supporting a mandibular overdenture on the condition of the peri-implant tissues. Sixty edentulous patients (Cawood class V VI) participated in this study. After randomization, thirty patients were treated with an overdenture supported by two IMZ implants (group A) and thirty patients with an overdenture on four IMZ implants (group B). The implants were inserted in the anterior region of the mandible. After three months overdentures were constructed, supported by round bar and clip attachments. A standardized clinical and radiographic evaluation was performed 0, 6 and 12 months after insertion of the denture. One implant was lost (group A) during the healing period. There were no significant differences with regard to any of the studied clinical or radiographic parameters of the peri-implant tissues, neither were significant differences found between the lateral and central implants in group B. None of the patients reported a sensory change in lip or chin region. From this study it is concluded that there seems to be no need to insert more than two endosteal implants to support an overdenture, however, long-term prospective studies are needed to support this notion.

The cost of dental implants as compared to that of conventional strategies.

The effectiveness of dental implants is widely studied, especially in terms of their clinical outcomes. However, from the policymaker's point of view, variables other than safety and efficacy, such as the costs and effectiveness of dental implants as compared to other treatment alternatives, are vital in decision making. This paper compares the costs of different treatment strategies in a randomized clinical trial in patients with resorbed mandibles and persistent problems with their conventional dentures: treatment with a mandibular overdenture on permucosal dental implants, an overdenture on a transmandibular implant, new dentures after preprosthetic surgery, and new dentures only. Data were gathered on an individual patient level to gain insight into specific cost episodes. Direct costs were subdivided into labor, material, technique, and overhead. Data concerning these components were gathered during the consecutive treatment phases in the first year. Results show that the resources used to treat a patient with an overdenture supported by a transmandibular implant are seven times those of a complete new set of dentures. Comparison of the cost ratio of an implant-retained overdenture supported by permucosal implants and conventional new prostheses proves less unfavorable: 1:3. New dentures after preprosthetic surgery are almost as expensive as treatment with permucosal implants.

Overdentures stabilised by two IMZ implants in the lower jaw--a 5-8 year retrospective study.

Clinical and radiographical parameters were assessed in forty patients with overdentures stabilised by two IMZ implants connected by a bar in the lower jaw in a 5-8 years retrospective study. Results indicated that most patients had healthy peri-implant tissues, the mean pocket probing depth was 3.1 mm and the median periotest value was -4. Three implants were removed after the healing period and replaced by three new implants. One implant was lost after six years. One implant was mobile on palpation. None of the patients showed objective signs of dysaesthesia in the lower lip or chin. The peri-implant bone level of most implants had remained stable after one year of service. The overall success rate was 94% (Albrektsson et al.) and it is therefore concluded that two IMZ implants, connected with a bar in the lower jaw, provide a stable base for long-term support of a mandibular overdenture.

[Fixation of facial and auricular prosthesis with osseous implants in cranial bone]. / Fixatie van gelaats- en oorschelpprothesen met implantaten in schedelbot.

OBJECTIVE: To evaluate the use of osseointegrated implants to fix facial and auricular prostheses. DESIGN: Retrospective. SETTING: University Hospital Groningen, the Netherlands. METHODS: Thirty patients were treated with Brånemark implants for fixation of auricular (21 patients) and orbital (9 patients) prostheses during May 1988-December 1995. The complications during the procedure, the success rate of the implants, skin reactions around the implants and patient satisfaction were recorded. RESULTS: A total of 97 implants were placed. One implant had to be removed after the healing period because it was loose. No other implants were lost during the follow-up period (mean 36 months; range: 12-91). The skin around the implants sometimes showed a mild reaction which could be adequately treated. In most of the cases no inflammation of the skin was observed. Retention, ease of handling and wearing comfort of the facial prostheses were excellent. CONCLUSION: Fixation of facial and auricular prostheses can be improved by osseointegrated implants resulting in high patient satisfaction.

The mandibular staple bone plate: a long-term retrospective evaluation.

PURPOSE: Clinical and radiographic parameters and denture satisfaction were evaluated in a long-term retrospective study of patients treated with the mandibular staple bone plate. PATIENTS AND METHODS: Fifty-six edentulous patients were treated with the mandibular staple bone plate to stabilize their lower denture. The mean evaluation period was 103 months (range, 84 to 139 months). Peri-implant mucosa and bone height were scored, together with quality of the prosthesis and prosthodontic maintenance care. Denture satisfaction was assessed by using two questionnaires. RESULTS: Four staple bone plates were removed during the evaluation period, and one appeared to be fractured. The remaining 51 staple bone plates were functional without any signs of major complications (survival rate, 91%). No further alveolar resorption in the interforaminal region of the mandible took place during the evaluation period. Patients were very satisfied with the prosthetic construction. CONCLUSIONS: The mandibular staple bone plate is a good modality to stabilize the lower denture. However, endosseous implant systems are preferred because of comparable success rates with a more simple operative procedure.

Mandibular overdentures supported by two Brånemark, IMZ or ITI implants. A prospective comparative preliminary study: one-year results.

The aim of this prospective comparative study was to evaluate the condition of the peri-implant tissues of three different implant systems supporting a mandibular overdenture. Ninety edentulous patients (Cawood class V-VI) participated in this study. After randomization, 30 patients were treated with 2 Brånemark implants, 30 patients with 2 IMZ implants and 30 patients with 2 ITI implants. The implants were inserted in the canine region of the mandible. After 3 months overdentures were fabricated supported by a round bar and clip attachment. A standardized clinical and radiographic evaluation was performed 0,6 and 12 months after insertion of the denture. The intraoral radiographs were made, using the long-cone technique with an aiming device. Two implants were lost (1 Brånemark, 1 IMZ) during the healing period. None of the patients showed any sensory change in lip or chin region. The pocket depth in the Brånemark group decreased significantly whereas the mucosa recession increased significantly in both the Brånemark as well as in the IMZ group. After 12 months, there was significantly less bone loss in the ITI group. From our study it was concluded that 2 (Brånemark, IMZ or ITI) implants placed in the interforaminal region connected with a bar supply a proper base for the support of a mandibular overdenture in the (Cawood V-VI) edentulous patient. The ITI implant appears to be the implant of choice for mandibular overdenture therapy, because only one operation is required for a comparable result.