Do Implant Retained Prostheses Improve the Quality of Life of Patients with Extraoral Maxillofacial Defects - A Systematic Review.

BACKGROUND: There is limited evidence available regarding patient satisfaction and quality of life assessment in patients with extraoral maxillofacial prostheses. OBJECTIVES: This systematic review aims to understand the impact of extraoral implant retained prosthesis in improving the quality of life in patients with extraoral maxillofacial defects/abnormalities. METHODS: A comprehensive search was performed of nine electronic databases up to August 2022, which yielded three articles that satisfied the inclusion criteria. The study characteristics and findings were extracted, and the included studies were assessed for quality. RESULTS: Three cohort studies were selected. Despite the lack of uniformity in the quality of life instruments, there was a general trend in improvement in the quality of life for patients with implant retained extraoral prostheses. The studies were also deemed to be of high quality on assessment. CONCLUSION: Given the limitations of this systematic review, there exists limited evidence indicating that implant prostheses may enhance the quality of life for individuals with extraoral maxillofacial defects or abnormalities.

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.

[Three dimensional technology and reconstructions of large defects of the jaw]. / Driedimensionale technologie en reconstructies van grote kaakdefecten.

3D technology is increasingly being applied in dentistry and in oral and maxillofacial surgery. An important field of application is reconstructive surgery, especially in the reconstruction of large defects ofthe jaw. In such cases of reconstruction, the goal is the restoration of both the continuity of the defective area and its function. For the functional restoration implant supported dental structures are often employed. In such cases, CAD/CAM superstructures, 3D printed drill and saw templates, anatomical models, wafers and surgical outcome models are used. The combination of the digital planning and the digital fabrication ofsuperstructures and surgical aids offers many preoperative advantages. The use of saw, drill and positioning templates provides for accurate segmentation and implant positioning, by means of which the reconstruction can be carried out in a predictable way.

Planned dose of intensity modulated proton beam therapy versus volumetric modulated arch therapy to tooth-bearing regions.

BACKGROUND: Intensity modulated proton beam therapy (IMPT) for head and neck cancer offers dosimetric benefits for the organs at risk when compared to photon-based volumetric modulated arch therapy (VMAT). However, limited data exists about the potential benefits of IMPT for tooth-bearing regions. The aim of this study was to compare the IMPT and VMAT radiation dosimetrics of the tooth-bearing regions in head and neck cancer patients. Also, we aimed to identify prognostic factors for a cumulative radiation dose of ≥40 Gy on the tooth-bearing areas, which is considered the threshold dose for prophylactic dental extractions. METHODS: A total of 121 head and neck cancer patients were included in this retrospective analysis of prospectively collected data. We compared the average Dmean values of IMPT versus VMAT of multiple tooth-bearing regions in the same patients. Multivariate logistic regression analysis was performed for receiving a cumulative radiation dose of ≥40 Gy to the tooth-bearing regions (primary endpoint) in both VMAT and IMPT. RESULTS: A lower Dmean was seen after applying IMPT to the tooth-bearing tumour regions (p < 0.001). Regarding VMAT, oral cavity tumours, T3-T4 tumours, molar regions in the mandible, and regions ipsilateral to the tumour were risk factors for receiving a cumulative radiation dose of ≥40 Gy. CONCLUSIONS: IMPT significantly reduces the radiation dose to the tooth-bearing regions.

Immediate implant-retained prosthetic obturation after maxillectomy based on zygomatic implant placement by 3D-guided surgery: a cadaver study.

BACKGROUND: The aim of this study was to introduce a complete 3D workflow for immediate implant retained prosthetic rehabilitation following maxillectomy in cancer surgery. The workflow consists of a 3D virtual surgical planning for tumor resection, zygomatic implant placement, and for an implant-retained prosthetic-obturator to fit the planned outcome situation for immediate loading. MATERIALS AND METHODS: In this study, 3D virtual surgical planning and resection of the maxilla, followed by guided placement of 10 zygomatic implants, using custom cutting and drill/placement-guides, was performed on 5 fresh frozen human cadavers. A preoperatively digitally designed and printed obturator prosthesis was placed and connected to the zygomatic implants. The accuracy of the implant positioning was obtained using 3D deviation analysis by merging the pre- and post-operative CT scan datasets. RESULTS: The preoperatively designed and manufactured obturator prostheses matched accurately the per-operative implant positions. All five obturators could be placed and fixated for immediate loading. The mean prosthetic point deviation on the cadavers was 1.03 ± 0.85 mm; the mean entry point deviation was 1.20 ± 0.62 mm; and the 3D angle deviation was 2.97 ± 1.44°. CONCLUSIONS: It is possible to 3D plan and accurately execute the ablative surgery, placement of zygomatic implants, and immediate placement of an implant-retained obturator prosthesis with 3D virtual surgical planning.The next step is to apply the workflow in the operating room in patients planned for maxillectomy.

[Cheek paresthesia by an osteosarcoma]. / Paresthesie van de wang door een osteosarcoom.

A 21-year-old woman was referred by the dental practitioner to an oral surgeon concerning a hard elastic swelling of the left cheek in combination with local paresthesia. Histopathologic and radiographic examination revealed an osteosarcoma in the left segment of the maxilla. Subsequently, the patient was referred to a medical centre for head and neck oncology. The treatment consisted of 3 courses neoadjuvant chemotherapy, followed by radical surgical resection of the tumor, and 3 courses adjuvant chemotherapy. One year after treatment, there was no sign of local tumor recurrence or metastases. An osteosarcoma is a malignant tumor of bone forming cells. About 10% of osteosarcomas are appearing in the head and neck region, primarily in the mandible and the maxilla. The treatment of choice is adequate surgical removal. Treatment with (neo)adjuvant chemotherapy seems to have additional benefit, but this needs further research.

[Removable partial dentures in maxillo-facial prosthetics]. / De frameprothese in de maxillofaciale prothetiek.

In maxillo-facial prosthodontics, removable partial dentures are still widely used for tooth replacement, but also for the replacement of bone and soft tissue or for soft tissue support. The original indication range has partially been taken over by implant-supported prostheses, especially in cases involving congenital defects. Despite this trend, removable partial dentures are still the treatment of choice in head and neck oncology rehabilitation and in cleft and trauma patients.

Prosthodontic rehabilitation of oral function in head-neck cancer patients with dental implants placed simultaneously during ablative tumour surgery: an assessment of treatment outcomes and quality of life.

The aim of this prospective study was to assess treatment outcome and impact on quality of life of prosthodontic rehabilitation with implant-retained prostheses in head-neck cancer patients. Fifty patients were evaluated by standardized questionnaires and clinical assessment. All received the implants during ablative tumour surgery in native bone in the interforaminal area. About two-thirds of the patients (n=31) needed radiotherapy post-surgery. Both in irradiated and non-irradiated bone two implants were lost 18-24 months after installation. Peri-implant tissues had a healthy appearance. No cases of osteoradionecrosis occurred. In 15 patients no functional implant-retained lower dentures could be made for various reasons. The other 35 patients all functioned well, with an improvement in quality of life. Major improvement was observed in the non-irradiated patients. In the irradiated patients, less improvement in many functional items was observed, while items related to the oral sequelae of radiotherapy did not improve. Similar to the quality-of-life assessments, denture satisfaction was improved and tended to be higher in non-irradiated than irradiated patients. Implant-retained lower dentures can substantially improve the quality of life related to oral functioning and denture satisfaction in head-neck cancer patients. This effect is greater in non-irradiated than irradiated cancer patients.

[Prosthetic dilemmas. Choice of superstructure for the edentulous maxilla]. / Prothetische dilemma's. Suprastructuurkeuze in de edentate bovenkaak.

Patients with an edentulous maxilla can experience problems with a full upper denture. The most common problems are a lack of retention and the stability of the denture, but also other factors, such as an extreme gagging reflex, influence satisfaction. Attachment of a prosthesis on dental implants is a reliable solution to solve or diminish the above mentioned problems. The choice of the kind of superstructure, a removable overdenture or a fixed prosthesis, depends on a variety of factors, such as degree of resorption of the maxilla, cleaning possibilities, patients'wishes and financial possibilities

[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.

Surgery for extra-articular trismus: a systematic review.

The aim of this systematic review was to identify operations that are used to improve mouth opening in patients with extra-articular trismus (caused by cancer and its treatment, oral submucous fibrosis, or noma) and to find out if they work. We searched the electronic databases PubMed, Embase, Cinahl, and the Cochrane collaboration, and then systematically selected papers before we assessed their quality, extracted the data, and did a meta-analysis. We analysed 32 studies that included 651 patients, the median (IQR) size of which was 11 (7-26). The quality of the methods used and of reporting were relatively low. Median (IQR) duration of follow-up was 12 (8-22) months. Operations resulted in a weighted mean (SD) increase in mouth opening of 19.3 (6.3) mm. None of the operations was better than the others for the improvement of mouth opening. We conclude that operations can improve mouth opening in extra-articular trismus, but the evidence is of moderate quality and there is a need for further research.

An in vivo study of microhardness and fluoride uptake in partially demineralized human enamel covered by plaque.

In this investigation, microhardness changes in partially demineralized human enamel were studied after in vivo use of fluoridated toothpaste systems. Flattened enamel specimens were demineralized in vitro and subsequently positioned in approximal positions in the prostheses of 27 participants for three weeks; the samples were plaque-covered in vivo. After brushing for one week with a non-fluoridated paste to achieve an in vivo equilibrium, participants brushed with an assigned product for a two-week period. This test was a six-way cross-over design which used randomization of subjects. Five fluoridated and one non-fluoridated paste were tested. Knoop hardness measurements were carried out on sound and on in vitro demineralized enamel, and after in vivo exposure of the enamel to the dentifrice treatments. The results showed that during the two weeks of in vivo exposure to the fluoride products, net rehardening of the demineralized enamel did not occur, and no correlation was observed between fluoride uptake into the demineralized enamel and changes in microhardness. That we failed to observe rehardening may be due to the fact that the duration of this study was too short for any net remineralization to have occurred, especially because the samples were constantly covered with plaque. Other possibilities, such as the type and/or severity of the lesions used in this study, may account for the lack of rehardening.

An in vivo investigation of the fluoride uptake in partially demineralized human enamel from several different dentifrices.

In this study, the total fluoride uptake in partially demineralized enamel from in situ brushing with six dentifrice systems was investigated in vivo among 22 panelists. Five dentifrices with different fluoride systems were compared with a placebo control. Two demineralized enamel discs were placed in proximal positions on specially fabricated dentures worn by each participant. Each treatment involved use of the placebo dentifrice for one week, followed by two weeks of twice-daily use of the test dentifrice. The F- contents of the dentifrices were: A = 1000 ppm F as Na2PO3F + 450 ppm F as NaF; B = 1100 ppm F as NaF; C = 1000 ppm F as Na2PO3F; D = 1000 ppm F as SnF2; E = 1500 ppm F as Na2PO3F; and P = 0 ppm F (placebo). The F- uptakes from A, C, D, and E were not significantly different from each other but were all significantly higher than the placebo. Statistical analysis showed a significantly higher F- level from the NaF-based paste B than that from all other systems. No differences existed between mesial-distal specimens; there was no correlation between F- uptake and age. Significant uptake differences were found between panelists with full and partial prostheses.

The use of implant retained mandibular prostheses in the oral rehabilitation of head and neck cancer patients. A review and rationale for treatment planning.

Surgical treatment of malignancies in the oral cavity (tongue, floor of the mouth, alveolus, buccal sulcus, oropharynx) often results in an unfavourable anatomic situation for prosthodontic rehabilitation. The outcome is a severe disturbance of oral functioning despite the improved surgical techniques for reconstruction that are currently available. Radiotherapy, which often is applied postsurgically, worsens oral functioning in many cases. Main problems that may hamper proper prosthodontic rehabilitation of these patients include a severe reduction of the neutral zone, an impaired function of the tongue, and a very poor load-bearing capacity of the remaining soft tissues and mandibular bone. Many of these problems can, at least in part, be diminished by the use of endosseous oral implants. These implants can contribute to the stabilisation of the prostheses and intercept the main part of the occlusal loading. Surgical interventions after radiotherapy are preferably avoided because of compromised healing, which may lead to development of radionecrosis of soft tissues and bone as well as to increased implant loss. If surgical treatment after radiotherapy is indicated, measures to prevent implant loss and development of radionecrosis have to be considered e.g. antibiotic prophylaxis and/or pre-treatment with hyperbaric oxygen (HBO). To avoid this problem, implant insertion during ablative surgery has to be taken into consideration if postoperative radiotherapy is scheduled or possibly will be applied. This approach is in need of a thorough pre-surgical examination and multidisciplinary consultation for a well-established treatment planning. The primary curative intent of the oncological treatment and the prognosis for later prosthodontic rehabilitation have to be taken into account too.

Indications for extra-oral implantology.

In this paper, the general indications for implantology for facial prosthesis in the maxillofacial bones are elaborated. Information from both the literature and our own surgical experience emphasizes that only specific locations of the facial bones and skull are suitable for implant fixtures. Careful indication and surgery are required for patients who were exposed to radiotherapy. The success of maxillofacial rehabilitation depends on multidisciplinary cooperation.

Fixation of auricular prostheses by osseointegrated implants.

Placement of enosseous implants in the temporal bone may overcome the apparent disadvantages of skin adhesives and skinpockets for the fixation of auricular prostheses. The surgical procedure for placement of implants in the temporal bone and the results obtained in eight patients wearing implant-supported auricular prostheses are described. From the results of this study, it is obvious that osseointegrated implants have great advantages compared with skin adhesives and skinpockets to rehabilitate patients suffering from auricular defects. The major achievement of implant-supported auricular prostheses is the patients' increased comfort and confidence wearing these types of prostheses.

Use of the final denture base for the intermaxillary registration in an implant-supported overdenture: technical note.

A method of implant-retained overdenture treatment based on the early use of the final denture base during registration of the maxillomandibular jaw relation is described. Using this stable denture base, an accurate recording of jaw relation and an adequate try-in procedure are facilitated without displacement of the base, especially in the situation of an unfavorable flat edentulous mandibular residual ridge.

Bone grafting of the floor of the maxillary sinus for the placement of endosseous implants.

This study describes and evaluates a technique to augment the floor of the maxillary sinus and to widen the alveolar crest of the atrophic posterior maxilla with autogenous bone. The subjects were 43 patients whose maxillary alveolar crest was not high enough to permit reliable placement of endosseous implants in the posterior maxilla. Large autogenous cancellous bone grafts (n = 37) or smaller grafts from the mandibular symphyseal area (n = 5) or the maxillary tuberosity (n = 1) were harvested. The operations were done in either one stage (n = 20 patients, 36 sinuses) or two (bone grafting followed by placement of implants, n = 23, 45 sinuses). In 28 cases the sinus membrane was perforated with no subsequent problems. Nine of the 171 Brånemark implants that were inserted were lost during follow-up (mean 26 months, range 8-62 months). Augmentation of the maxillary sinus with autogenous bone is a reliable way of achieving placement of an implant.

Efficacy of a synthetic polymer saliva substitute in reducing oral complaints of patients suffering from irradiation-induced xerostomia.

OBJECTIVE: A saliva substitute based on polyglycerylmethacrylate, lactoperoxidase, and glucose oxidase (Oral Balance) has been developed. The aim of this study was to evaluate the effect of Oral Balance on the dryness-related oral complaints in patients suffering from irradiation-induced xerostomia. METHOD AND MATERIALS: The efficacy of Oral Balance on the dryness-related complaints of 28 patients was assessed by means of self-administered questionnaires. Each patient completed an initial questionnaire about dryness-related symptoms and then was given the moistening gel. The patients were instructed to apply the gel as often as desired. After 2 weeks and 3 months, the patients were asked to complete a progress questionnaire. The severity of xerostomia was measured with a saliva absorption method. RESULTS: All patients suffered from moderate-to-severe xerostomia, the severity of which did not change during the experimental period. Three patients did not complete the study. In the other 25 patients, the application of Oral Balance tend to diminish the sensation of oral dryness and improve oral functioning. Statistically significant reduction of the dryness-related complaints was observed only in the patients suffering from severe xerostomia. CONCLUSION: Use of Oral Balance is of potential benefit in patients suffering from severe xerostomia.