Maxillary bone grafting for insertion of endosseous implants: results after 12-124 months

Insertion of endosseous implants in the atrophic maxilla is often complicated because of lack of supporting bone. Augmentation of the floor of the maxillary sinus with autogenous bone graft has been proven to be a reliable treatment modality, at least in the short term. The long-term clinical and radiographic outcome with regard to the grafts, the implants and satisfaction of the patients with their implant-supported overdenture was studied in 99 patients. The sinus floor was augmented with bone grafts derived from the iliac crest (83 subjects, 162 sinuses, 353 implants), the mandibular symphysis (14, 18, 37), or the maxillary tuberosity (2, 2, 2). Before implant installation, the width and height of the alveolar crest were increased in a first stage procedure in 74 patients, while in the other 25 patients augmentation and implant installation could be performed simultaneously (width and height of the alveolar crest >5 mm). Perforation of the sinus membrane occurred in 47 cases, which did not predispose to the development of sinusitis. Loss of bone particles and sequestration were observed in one (diabetic) patient only, in whom a dehiscence of the oral mucosa occurred. A second augmentation procedure was successful in this patient. Symptoms of transient sinusitis were observed in 3 patients. These symptoms were successfully treated with decongestants and antibiotics. 2 other patients developed a purulent sinusitis which resolved after a nasal antrostomy. In all cases, the bone volume was sufficient for implant insertion. 32 of 392 inserted Brånemark implants (8.2%) were lost during the follow-up. After the healing period of the bone grafts, no sinus pathology was observed. The patients received implant-supported overdentures (72 patients) or fixed bridges (27 patients). Overall, the patients were very satisfied with the prosthetic construction. We conclude that bone grafting of the floor of the maxillary sinus floor with autogenous bone for the insertion of implants is a reliable treatment modality with good long-term results.

Augmentation of the maxillary sinus floor with autogenous bone for the placement of endosseous implants: a preliminary report

Placement of endosseous implants in the atrophic maxilla is often restricted because of lack of supporting bone. In this article, experience with augmentation of the maxillary sinus floor with autogenous bone grafts to enable insertion of endosseous implants is described. The technique is aimed at providing a cortical layer on top of the graft to ensure a reliable seal of the maxillary sinus and to achieve optimal stability of the bone graft in case of simultaneously placement of dental implants. The procedure was used in 25 patients, using iliac crest grafts (22 patients, 86 implants), symphyseal bone grafts (two patients, six implants), or a maxillary tuberosity bone graft (one patient, one implant). Ninety-three Brånemark implants (Nobelpharma, Götenburg, Sweden) were inserted in 47 grafted maxillary sinuses. The mean follow-up was 16 months (range, 6 to 36 months). No inflammation of the bone grafts nor of the maxillary sinus occurred. The sinus membrane was perforated accidentally in eight cases during the surgical procedure. Five implants (5.4%), all inserted in iliac crest grafts, were lost during the healing period. The patients received implant supported overdentures (16 patients) or bone-anchored bridges (nine patients). From this preliminary study it is concluded that augmentation of the maxillary sinus floor with bone grafts for the insertion of endosseous implants is a promising solution for patients with atrophic maxillae and functional problems with their partial or full dentures.

Augmentation of localized defects of the anterior maxillary ridge with autogenous bone before insertion of implants

PURPOSE

This study evaluated the applicability of intraorally harvested autogenous bone grafts for the augmentation of the narrow maxillary alveolar ridge to enable insertion of implants for single tooth replacement.

MATERIALS AND METHODS

Local defects of the anterior maxilla were reconstructed in 27 patients with autogenous bone grafts from the mandibular symphysis (n = 12), maxillary tuberosity (n = 8), or mandibular retromolar area (n = 7). Three months after grafting, either Branemark (n = 23) or ITI Bonefit implants (n = 8) were inserted.

RESULTS

At the time of implantation, all grafted sites showed sufficient bone volume for insertion of the implants. Twenty-four to 68 months after insertion, all implants were functioning well.

CONCLUSION

Augmentation of local alveolar defects in the maxilla with intraorally harvested autogenous bone grafts appears to be a reliable method to enable implant placement.

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.

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.

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.

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.

Morbidity and complications of bone grafting of the floor of the maxillary sinus for the placement of endosseous implants

Placement of endosseous implants in the atrophic maxilla is often limited because of a lack of supporting bone. A technique to augment the floor of the maxillary sinus with autogenous bone graft seems to be a new reliable treatment modality. The morbidity and complication rate of augmentation of the maxillary sinus floor was studied in 75 patients. The sinus floor was augmented with iliac crest (n = 65, 128 sinuses, 276 implants), mandibular symphysis (n = 8, ten sinuses, 21 implants), or maxillary tuberosity grafts (n = 2, two sinuses, two implants). The width of the alveolar crest had to be reconstructed in 52 patients, while in the other 23 patients augmentation and implantation were performed simultaneously. Perforation of the sinus membrane occurred in 45 patients, but this did not predispose them to the development of sinusitis. Loss of bone particles and sequesters were observed in one (diabetic) patient only, in whom a mucosal dehiscence occurred. A second augmentation procedure was successful. Symptoms of transient sinusitis were observed in two of the seven patients with a predisposition for sinusitis. These symptoms were successfully treated with decongestants and antibiotics. One patient developed a purulent sinusitis which resolved after a nasal amrostomy. The bone volume was sufficient for insertion implants in all patients. Twenty of 299 patients (6.7%) in whom Brånemark implants had been inserted were lost to follow-up (mean, 32 months); no sinus pathology was observed. The patients received implant-supported overdentures (58 patients) or fixed bridges (17 patients) and experienced no complaints with regard to the grafts or implants. We conclude that the morbidity and complication rate of bone grafting of the floor of the maxillary sinus floor with autogenous bone is low.

Overdentures supported by two IMZ implants in the lower jaw. A retrospective study of peri-implant tissues

Between 1987 and 1990, 57 edentulous patients were treated with overdentures supported by 2 endosseous IMZ implants connected by a bar in the lower jaw. The condition of the peri-implant tissue was evaluated for a loading period ranging from 12 to 57 months (mean 30 months and median 24 months). The evaluation parameters included Plaque Index, Bleeding Index, Gingiva Index, pocket depth, dysesthesia of chin or lip, peri-implant bone loss and loss of implants. During the healing phase prior to the construction of an overdenture, 3 implants were lost. After a healing period of 6 months, these implants were successfully replaced. During the follow-up period, a Plaque Index < or = 1 was observed in 45 patients and an abundance of plaque and calculus was observed in 1 patient. Heavy or profuse bleeding and severe gingival inflammation was observed in 3 patients. The mean pocket depth was 3.6 +/- 1.7 mm. None of the patients experienced lip or chin dysesthesia. Marginal bone loss was observed around 30 (26%) implants. From this study it is concluded that, once proper osseointegration is obtained, 2 IMZ implants connected with a bar in the lower jaw supply a proper base for the support of an overdenture; the condition of the peri-implant tissues is steady and independent of the follow-up time.

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.

'Calcium fluoride-like' material formed in partially demineralized human enamel in vivo owing to the action of fluoridated toothpastes

In this paper are presented the results of a chemical analysis of partially demineralized enamel lesions positioned under plaque in vivo for 3 weeks. During the experimental period the samples were brushed with fluoridated or non-fluoridated toothpaste systems. After the experiment the fluoride and protein uptake was determined. Furthermore, KOH extractions of the lesions were carried out and the solutions analyzed for calcium, fluoride, and phosphate. The results show that 'CaF2-like' material is most likely formed inside lesions during the in vivo period. This in indicated from chemical analysis, Raman spectroscopy, and SEM observations. The amount of CaF2-like material is on the order of 0.1 wt% if we consider its formation all over the enamel lesions, or 1 wt% if we assume its formation in interprismatic regions of the enamel only. About 40% of the fluoride taken up from toothpaste systems is in the form of CaF2-like material. In vivo there is a substantial influx of proteins (approximately 0.3%) and also a very large influx of phosphate ions. The effect of CaF2-like material is most likely strongly dependent on conditions in the lesion, such as pH change.

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.

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.

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.

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.

[Augmentation of the maxillary sinus floor and alveolar ridge for placement of endosseous implants in the edentulous maxilla]

Placement of endosseous implants in the atrophic maxilla is often restricted because of lack of supporting bone limiting placement of implants of adequate length in a prosthodontically optimal position. There are several surgical procedures to create sufficient volume of bone for the placement of implants. In this paper, a technique is described for augmentation of the maxillary sinus floor and simultaneous widening of the alveolar crest with autogenous bone.

[A prosthodontic concept using implants in the resorbed edentulous maxilla]

For the treatment of the atrophic edentulous maxilla implant supported overdentures provide the opportunity to obtain proper lip support, speech and cleanliness. A superstructure with high rigidity is needed for an optimal distribution of occlusal loading, to ensure good prognosis for implant survival. A prosthodontic concept using a hybrid construction meets these criteria. It consists of a cast and precision-milled mesostructure fixed to the implants, over which that a removable cast prosthodontic device is placed to which the teeth are attached. It is essential to follow a strict treatment protocol to obtain a good and predictable result.

[Three dimensional technology and reconstructions of large defects of the jaw]

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.

[Fixation of facial and auricular prosthesis with osseous implants in cranial bone]

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.