Effectiveness of Lateral Bone Augmentation on the Alveolar Crest Dimension: A Systematic Review and Meta-analysis.

Lateral ridge augmentation procedures are aimed to reconstruct deficient alveolar ridges or to build up peri-implant dehiscence and fenestrations. The objective of this systematic review was to assess the efficacy of these interventions by analyzing data from 40 clinical studies evaluating bone augmentation through either the staged or the simultaneous approach. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guideline for systematic reviews was used. The primary outcomes were the changes at reentry, in the ridge width, and in the vertical and horizontal dimensions of the peri-implant defect, measured in millimeters, in the staged and simultaneous approaches, respectively. The results of the meta-analysis showed, for the simultaneous approach, a statistically significant defect height reduction when all treatments were analyzed together (weighted mean difference [WMD] = -4.28 mm; 95% confidence interval: [CI] -4.88, -3.69; P < 0.01). The intervention combining bone replacement grafts with barrier membranes was associated with superior outcomes The most frequently used intervention was the combination of xenograft and bioabsorbable membrane. Similarly, for the staged approach, there was a statistically significant horizontal gain when all treatment groups were combined (WMD = 3.90 mm; 95% CI: 3.52, 4.28; P < 0.001). The most frequently used intervention was the use of autogenous bone blocks. Both treatment strategies led to high survival and success rates (>95%) for the implants placed on the regenerated sites. Nonexposed sites gained significantly more in the simultaneous and staged approaches (WMD = 1.1 and 3.1 mm).

Evaluation of the treatment modalities for neurosensory disturbances of the inferior alveolar nerve following retromolar bone harvesting for bone augmentation.

SUBJECTS: The purpose of this study was to evaluate the treatment modalities for neurosensory disturbances (NSDs) of the inferior alveolar nerve occurring after retromolar bone harvesting for bone augmentation procedures before implant placement. METHODS: One hundred four patients, of which 49 and 55 exhibited vertical or horizontal alveolar ridge defects in the mandible and maxilla, respectively, were enrolled. Nineteen patients underwent block bone grafting, 38 underwent guided bone generation or autogenous bone grafting combined with titanium mesh reconstruction, and 47 underwent sinus floor augmentation. Using a visual analog scale, we examined subjective symptoms and discomfort related to sensory alteration within the area of the NSDs in these patients. NSDs were clinically investigated using a two-point discrimination test with blunt-tipped calipers. In addition, neurometry was used for evaluation of trigeminal nerve injury. We tested three treatment modalities for NSDs: follow-up observation (no treatment), medication, and stellate ganglion block (SGB). RESULTS: A week after surgery, 26 patients (25.0%) experienced NSDs. Five patients received no treatment, 10 patients received medication, and 11 patients received SGB. Three months after surgery, patients in the medication and SGB group achieved complete recovery. Current perception threshold values recovered to near-baseline values at 3 months: recovery was much earlier in this group than in the other two groups. SGB can accelerate recovery from NSDs. CONCLUSIONS: Our results justify SGB as a reasonable treatment modality for NSDs occurring after the harvesting of retromolar bone grafts.

Three-dimensional bone and soft tissue requirements for optimizing esthetic results in compromised cases with multiple implants.

Achieving an esthetic outcome in tooth replacement and implant treatment requires a proper tooth shape and stable surrounding soft tissue profiles. Bone augmentation is considered vital to support the esthetic soft tissue profile around definitive restorations. To prevent recession of the peri-implant soft tissue in cases with multiple implants, buccal bone augmentation of more than 2 mm from the implant platform is necessary to overcome the normal pattern of bone remodeling. Drawing an imaginary horizontal line spanning the space between the remaining healthy interproximal bone peaks is the most reliable vertical augmentation target to create esthetic papillae around an implant prosthesis. Provided that the adjacent bone peaks are at an ideal height and the bone is augmented vertically up to this line, the accepted general guideline of 2 to 3 mm of interproximal vertical bone augmentation from ideally placed implant platforms will invariably also be achieved. In addition, placing pontics in strategic positions to avoid consecutively placed implants has been suggested to facilitate vertical bone height preservation after bone augmentation. Even with esthetically successful results, there have been very few long-term studies on compromised cases with multiple implants. This will become more and more critical over time and must be remedied.

Distance between external cortical bone and mandibular canal for harvesting ramus graft: a human cadaver study.

BACKGROUND: The aims of this study are to determine the distance of the external surface of the buccal cortical plate to the inferior alveolar canal in the mandibular molar region and to propose a safe thickness for harvesting a mandibular ramus block graft. METHODS: Thirty-four cadavers consisting of 26 dentate jaws and eight jaws in the edentulous molar region were used in this study. All mandibular ramus grafts were harvested by one investigator with the grafts extending from the external oblique ridge (EOR) and 15 mm inferiorly in the apico-coronal direction and extending from the mid-buccal aspect of the first molar to the mid-buccal aspect of the third molar in the mesio-distal direction. Measurements were made of the cortical bone thickness of the harvested ramus graft and from the cemento-enamel junction (CEJ) to the EOR, the CEJ to the mandibular border, and the CEJ to the inferior alveolar nerve (IAN). RESULTS: The average buccal cortical plate thickness in dentate mandibles was 2.76 +/- 0.13 mm, whereas in edentulous posterior mandibles it was 2.52 +/- 0.32 mm. The IANs were exposed in all jaws but were intact. CONCLUSION: The safe thickness to harvest ramus grafts was determined to be 2.5 to 3.0 mm.

The treachery of mandibular angle augmentation.

Patients who present for alloplastic jaw angle augmentation have 2 potentially troublesome choices. The use of a silicone implant can mean unpredictable motion, and if the lower pterygomasseteric sling is breached during implant placement, the masseter insertion will ride up without anything to which to adhere. When the patient bites down, a bulge will be present.The porous alternative even has a ledge made to go under the gonial angle, which if not removed, guarantees violation of the pterygomasseteric sling and an implant that is longer than the muscle can cover. The inferior muscle insertion is disrupted and is left to ride up serendipitously.This article presents 5 instances of these issues in which one case required a revision via a modified Risdon approach to access the uncovered material which stuck out beyond the high riding masseter.The basic aim of this article is to advocate the need to maintain the pterygomasseteric sling, and describe the consequences of the failure to do so.

Revisiting the hopeless ridge: part I--challenging the gold standard.

Proper bone-augmentation strategies are essential to recreating natural function and esthetics, implant dentistry's paramount objective. Although autogenous grafts have historically been considered the gold standard among grafting materials, they are associated with higher complication rates, greater resorption, and lower implant success than some of the allograft alternatives. Demineralized allograft bone combined with a carrier that facilitates handling has been verified to be inductive and offer other benefits. Three reports are presented of patients treated with such allograft materials in combination with resorbable membranes.

Training standards in implant dentistry for general dental practitioners. A report.

In December 2005, the General Dental Council (GDC) convened a small working group to consider training standards for general dental practitioners (GDPs) who wish to practise implant dentistry. The membership of this group is given at the end of this report. The secretariat for the group was provided jointly by the GDC and the Faculty of General Dental Practice (UK). The remit of the group (which was independent of any organisation) was to consider what training standards would be necessary for a GDP before practising implant dentistry, to publish those standards, and then periodically to review them in the light of developments in implant dentistry. Such standards can be used not only by practitioners but also by the GDC in the consideration of patient complaints against dental practitioners who, allegedly, practise implant dentistry beyond the limits of their competence.

In vitro analysis of the accuracy of subtraction radiography and computed tomography scanning for determination of bone graft volume.

PURPOSE: This study evaluated the accuracy of digital subtraction radiography (DSR) and three-dimensional computed tomography (3D CT) for determination of bone graft volume in the maxillofacial region. MATERIALS AND METHODS: Standardized bone defects were made on the top of the alveolar ridge in 10 dry pig mandibles. To resemble the clinical situation, a bone block was harvested from the symphyseal region of the mandible and fixed in the defect. True bone graft volume was determined by the water displacement technique (VOL I) and correlated to direct measurements by calipers (VOL II). The mean gray value of the bone graft as imaged by DSR was correlated to the directly measured thickness. Furthermore, VOL I was correlated to the 3D CT of the bone graft (VOL III) and to the 3D CT with the bone graft fixed in the defect (VOL IV). RESULTS: There was a strong correlation between VOL I and VOL II (r = .95), whereas there was a poorer correlation between mean gray level in DSR and measured bone thickness (r = .63). A strong correlation was also registered between VOL I and VOL III (r = .97) and VOL I and VOL IV (r = .97).

[Five-year evaluation of implants in the resorbed maxilla]. / Vijfjaarsoverleving van implantaten in de geresorbeerde bovenkaak.

The survival of implants placed in the resorbed maxillae was investigated. Both edentulous and partially edentulous patients were evaluated including those who underwent 'sinus lift' procedures. The group of patients with a sinus floor augmentation showed a five-year cumulative survival rate varying between 100% for fixed bridges on implants in the partially edentulous maxillae and 75.6% for implants under overdentures placed in severely resorbed edentulous maxillae. It is concluded that placement of implants in the augmented sinus-floor is justified, if the patient is well informed. The procedure can provide a good solution for the prosthetic problems of patients with a resorbed maxilla.

Relaçäo entre o arco dental estabelecido e a crista do rebordo alveolar em prótese total / Relationship between the established dental arch and crest of the alveolar ridge in complete prostheses

Realizou-se um estudo das relaçöes entre as cristas dos rebordos alveolares, superiores e inferiores, e as posiçöes dos arcos dentais estabelecidos proteticamente, antes e após a montagem dos dentes. Verificou-se que a relaçäo em questäo se distribui segundo três padröes básicos: a) crista do rebordo envolvendo o arco dental, que foi chamado padräo "envolvente"; b) crista do rebordo coincidindo com o contorno do arco, que foi denominado "coincidente", e c) crista envolvida pelo arco dental, que foi chamado de "envolvido". Desses padröes, a maior freqüencia foi do padräo "envolvido", sendo 76,66 por cento nas próteses superiores e 60,0 por cento nas inferiores