Guided bone regeneration with autogenous block grafts applied to Le Fort I osteotomy for treatment of severely resorbed maxillae: a 4- to 6-year prospective study

Autogenous bone grafting with conventional implants vs zygomatic implants for atrophic maxillae: a retrospective study of the oral health-related quality of life

INTRODUCTION

Autogenous bone grafting (ABG)-combined or not with Le Fort I osteotomy (LFIO)-and zygomatic implants (ZI) are two reliable techniques for the fixed rehabilitation of atrophic maxillae. ZI allow a reduced treatment duration with no need to graft, immediate loading and in principle less morbidity. The aim of this retrospective study was to compare these two protocols on oral health-related quality of life (OHRQoL). We also discussed implant and prosthetic survival rates, and biological complications.

MATERIAL AND METHODS

All patients who benefited from ZI or ABG with conventional implants (CI) for a fixed maxillary rehabilitation, from November 2011 to April 2019, were included: 21 patients in the ABG group and 22 in the ZI group. OHRQoL was evaluated postoperatively by OHIP-14 questionnaire.

RESULTS

OHIP-14 median scores were respectively 6.5 (interquartile range [IQR] 2.0-13.0) and 6.0 (IQR 3.0-10.0) without significant difference (p = 0.97). Implant/prosthetic survival rates were 97.9%/100% and 97.1%/95.5%. Biological complications rates were 33.3% and 36.4% without significant difference (p = 0.83).

DISCUSSION

The type of surgery or prosthesis does not seem to affect final OHRQoL, implant and prosthetic survival rates or biological complications rates.

Survival Rates of Dental Implants in Autogenous and Allogeneic Bone Blocks: A Systematic Review

Background and Objectives: Preliminary studies emphasize the similar performance of autogenous bone blocks (AUBBs) and allogeneic bone blocks (ALBBs) in pre-implant surgery; however, most of these studies include limited subjects or hold a low level of evidence. The purpose of this review is to test the hypothesis of indifferent implant survival rates (ISRs) in AUBB and ALBB and determine the impact of various material-, surgery- and patient-related confounders and predictors. Materials and Methods: The national library of medicine (MEDLINE), Excerpta Medica database (EMBASE) and Cochrane Central Register of Controlled Trials (CENTRAL) were screened for studies reporting the ISRs of implants placed in AUBB and ALBB with ≥10 participants followed for ≥12 months from January 1995 to November 2021. The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias was assessed via several scoring tools, dependent on the study design. Means of sub-entities were presented as violin plots. Results: An electronic data search resulted in the identification of 9233 articles, of which 100 were included in the quantitative analysis. No significant difference (p = 0.54) was found between the ISR of AUBB (96.23 ± 5.27%; range: 75% to 100%; 2195 subjects, 6861 implants) and that of ALBB (97.66 ± 2.68%; range: 90.1% to 100%; 1202 subjects, 3434 implants). The ISR in AUBB was increased in blocks from intraoral as compared to extraoral donor sites (p = 0.0003), partially edentulous as compared to totally edentulous (p = 0.0002), as well as in patients younger than 45 as compared to those older (p = 0.044), cortical as compared to cortico-cancellous blocks (p = 0.005) and in delayed implantations within three months as compared to immediate implantations (p = 0.018). The ISR of ALBB was significantly increased in processed as compared to fresh-frozen ALBB (p = 0.004), but also in horizontal as compared to vertical augmentations (p = 0.009). Conclusions: The present findings widely emphasize the feasibility of achieving similar ISRs with AUBB and ALBB applied for pre-implant bone grafting. ISRs were negatively affected in sub-entities linked to more extensive augmentation procedures such as bone donor site and dentition status. The inclusion and pooling of literature with a low level of evidence, the absence of randomized controlled clinical trials (RCTs) comparing AUBB and ALBB and the limited count of comparative studies with short follow-ups increases the risk of bias and complicates data interpretation. Consequently, further long-term comparative studies are needed.

Staged autogenous calvarial bone grafting and dental implants placement in the management of oligodontia: a retrospective study of 20 patients over a 12-year period

Oligodontia demands multidisciplinary management due to its repercussions on dentofacial growth. To place implants to realize implant-borne fixed denture, preimplant surgery may be necessary if bone volumes are insufficient. Our aim was to assess bone increase following autogenic bone grafting and to discuss prosthetic options. Twenty patients followed for oligodontia, who underwent bone grafting, were treated from 2008 to 2019. Transversal and vertical bone levels were measured pre- and postoperatively to assess alveolar ridge augmentation. Mean horizontal grafting increase was 4.60 mm [standard deviation (SD) 0.79 mm], mean sinus lift increase was 9.95 mm (SD 2.35 mm). Mean implants placed per patient was 9, mean implants placed on grafted site was 5 per patient. Overall implant survival rate was 100%. All patients benefited from prosthetic procedures when it was planned to perform implant-borne fixed dentures. Within the framework of a complete treatment plan (involving paediatric dentistry, dentofacial orthopaedics, oral and maxillofacial surgery, and prosthodontics), autologous bone grafting combined or not with orthognathic surgery is fully adapted to patients with oligodontia. It allows reconstruction of favourable bone volumes for placement of implants to realize implant-borne fixed dentures, with high implant survival rates and great improvements to quality of life.

Complications related to zygomatic implants placement: A retrospective evaluation with 5 years follow-up

This retrospective study assessed zygoma implants in patients treated for upper maxilla extreme atrophy, trauma, cleft palate, or failed reconstruction. The implants were placed using Quad (4 zygoma implants) or mixed (zygoma and conventional implants in premaxilla) surgical technique, with intra-sinus or extra-sinus approach, followed by immediate or deferred loading. Clinical and radiographic evaluations were carried out at 5-year follow-up from loading. Implant survival, symptoms and signs of sinusitis, radiological alterations in terms of mucosal thickening or obliteration of the maxillary sinuses, oroantral communications, and peri-implant soft tissues were examined. A total of 42 patients, with 116 zygoma implants, were included in the study. The cumulative survival rate was 97.41%. One zygomatic bone fracture was assessed. Eight patients reported sinusitis, and two showed oro-antral communications. A comparison between mean pre- and post-operative Lund-Mackay scores showed a statistically significant increase of sino-nasal disease in the post-operative scores (p = 0.0019). Mucositis and gingival recession was observed in 21 and 8 implants respectively. Average recession was 2.52 ± 2.35 mm. According to our results, placement of zygoma implants has proved to be a predictable procedure, with a lower rate of severe complications compared to other treatment options in extreme upper jaw atrophy.

Digital Customized Titanium Mesh for Bone Regeneration of Vertical, Horizontal and Combined Defects: A Case Series

Background and Objective: Guided bone regeneration allows new bone formation in anatomical sites showing defects preventing implant rehabilitation. Material and Methods: The present case series reported the outcomes of five patients treated with customized titanium meshes manufactured with a digital workflow for achieving bone regeneration at future implant sites. A significant gain in both width and thickness was achieved for all patients. Results: From a radiographic point of view (CBTC), satisfactory results were reached both in horizontal and vertical defects. An average horizontal gain of 3.6 ± 0.8 mm and a vertical gain of 5.2 ± 1.1 mm. Conclusions: The findings from this study suggest that customized titanium meshes represent a valid method to pursue guided bone regeneration in horizontal, vertical or combined defects. Particular attention must be paid by the surgeon in the packaging of the flap according to a correct method called the "poncho" technique in order to reduce the most frequent complication that is the exposure of the mesh even if a partial exposure of one mesh does not compromise the final outcome of both the reconstruction and the healing of the implants.

The influence of prosthetic material on implant and prosthetic survival of implant-supported fixed complete dentures: a systematic review and meta-analysis

PURPOSE

Evaluating the impact of the prosthetic material on implant- and prosthetic survival of implant-supported fixed complete dentures.

STUDY SELECTION

Electronic and hand searches were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to identify clinical studies including at least 10 patients restored with implant-supported dentures. The primary outcome was to evaluate the implant survival rate according to the applied restorative materials. The prosthetic survival rate was evaluated as secondary outcomes.

RESULTS

Forty-one of 2254 studies were finally selected. A statistically significant difference (p = 0.0337) was found between implant survival rates in the main restorative groups (metal-ceramic:97%(95%CI [0.96;0.98]), all-ceramic:99%(95%CI [0.98;1.00]), metal-resin:97%(95%CI [0.96;0.98])). Prosthetic survival rates were: (metal-ceramic:95%(95%CI [0.89;0.97]), all-ceramic:97%(95%CI [0.92;0.99]), metal-resin:97%(95%CI [0.95;0.98]), with no statistically significant difference (p = 0.3796) between the groups. Chipping incidence rates were as follows: metal-ceramic:8%(95%CI[0.03;0.20]), all-ceramic:15%(95%CI [0.06;0.32]), and metal-resin:22%(95%CI [0.13;0.33]). Five types of exact restorative materials were identified (porcelain-fused-to-non-precious alloy, porcelain-fused-to-zirconia, precious-metal-acrylic-resin, non-precious-metal-acrylic resin, and PMMA). Again, implant survival rates were statistically significantly influenced by the applied restorative materials (p = 0.0126), whereas, no significant differences were reported regarding prosthetic survival rate.

CONCLUSIONS

Prosthetic material selection seems to have no clinically relevant influence on implant- and prosthetic survival rate in implant-supported fixed complete dentures. Due to the high chipping rate, quantifying prosthetic survival alone does not seem to be a reliable tool for evaluating the outcome of the restorations and providing recommendations. These results, along with the obvious lack of evidence, suggest that clinicians must exercise caution whenever porcelain-fused-to-zirconia or metal-resin restorations are considered.

Autogenous Mandibular Bone Graft for Maxillary Le Fort I Osteotomy Interpositional Gap in Orthognathic Surgery: A Technique Case Series

Correction of maxillofacial skeletal dental deformities often includes surgical interventions in the maxilla and mandible. Le Fort I maxillary osteotomies are performed to correct maxillary horizontal, vertical, and transverse discrepancies. Repositioning of the maxilla creates an interpositional gap in bone that can lead to pseudoarthrosis, instability, mobility, infection, and eventual relapse. Grafting the interpositional gap with bone creates mechanical stops to prevent relapse, provides a matrix for secondary ossification, accelerates bony union, and inhibits soft tissue herniation. This can be accomplished using autogenous bone harvested from the patient. Donor sites include the calvarium, rib, and iliac crest bone. Although these donor sites have their advantages and specific indications, they require a second surgical site, which can lead to potential complications, such as infection, donor site morbidity, pneumothorax, and gait disturbances. In conjunction with the Le Fort I maxillary osteotomy, for correction of maxillary deformities, the bilateral sagittal split mandibular osteotomy is a common procedure used for mandibular advancement, setback, and correction of mandibular asymmetry with or without concurrent genioplasty. Five patients (1 man and 4 women) underwent orthognathic surgery for correction of their maxillofacial skeletal dental deformities at the Loma Linda University Hospitals (Loma Linda, CA) from 2015 through 2017. This case series describes a technique to harvest autogenous bone from the posterior aspect of the distal sagittal split osteotomy segment of the mandible, which is milled and used to graft the interpositional gap in the maxilla. Principles of guided bone regeneration are incorporated to improve surgical outcomes.

Minimally Invasive Approach Based on Pterygoid and Short Implants for Rehabilitation of an Extremely Atrophic Maxilla: Case Report

INTRODUCTION

Extremely atrophic maxillae can be considered the most important indication for three-dimensional maxillary reconstruction. Different bone-augmentation techniques have been suggested to accomplish this. This article illustrates a minimally invasive approach to rehabilitation of the extremely atrophic maxilla.

MATERIAL AND METHODS

A 63-year-old male patient was referred for restoration of his totally edentulous maxilla with a fixed full-arch implant-prosthetic rehabilitation. Four short implants in the premaxillary region and 2 longer implants in the pterygomaxillary regions were inserted with piezoelectric implant site preparation.

DISCUSSION

At the 1-year follow-up appointment, no clinical or radiographic changes in the soft-tissue contours or crestal bone levels were observed.

CONCLUSION

This surgical approach, based on the combination of short implants in the premaxillary regions and pterygoid implants in the pterygomaxillary regions, represents a way to shorten treatment timing, minimize the risk of surgical complications, and reduce patient discomfort and costs.

Are Zygomatic Implants Associated With Maxillary Sinusitis?

PURPOSE

The purpose of the present study was to analyze the relation between zygomatic implants and symptomatic and radiologic modifications of the maxillary sinuses.

MATERIALS AND METHODS

A retrospective cohort study of patients who underwent zygomatic implant rehabilitation at the Clinic of Dentistry and Maxillofacial Surgery of the University of Verona from January 2005 through May 2014 was designed. The primary predictor variable was time (pre- vs postoperative). Concerning outcome variables, radiologic findings of thickened mucosa or opacification of the maxillary sinuses were evaluated on computed tomograms using the Lund-Mackay Staging System. Clinical symptoms were evaluated using the Sino-Nasal Outcome Test-20 (SNOT-20). The parameters assessed underwent descriptive statistical analysis.

RESULTS

The sample was composed of 41 patients (mean age, 54 yr; 61% women). Preoperatively, 12% had sinus findings. Postoperatively, 46% had sinus findings (P = .0001 by McNemar paired test). Preoperatively, 12% had a SNOT-20 score higher than 11. Postoperatively, 15% had a SNOT-20 score higher than 11 (P = 1 by McNemar paired test).

CONCLUSIONS

In accordance with data in the literature data, placement of zygomatic implants does not seem to be associated with severe rhinosinusitis complications. However, in a considerable number of patients, asymptomatic radiologic alterations of the paranasal sinuses were observed. Therefore, it is important to plan assessments of the prosthetic and peri-implant components of the procedure and the postoperative homeostasis of the maxillary sinuses.

A systematic review and meta-analysis of removable and fixed implant-supported prostheses in edentulous jaws: post-loading implant loss

Objectives

The aim of this systematic review was to analyze post‐loading implant loss for implant‐supported prostheses in edentulous jaws, regarding a potential impact of implant location (maxilla vs. mandible), implant number per patient, type of prosthesis (removable vs. fixed), and type of attachment system (screw‐retained, ball vs. bar vs. telescopic crown).

Material and methods

A systematic literature search for randomized‐controlled trials (RCTs) or prospective studies was conducted within PubMed, Cochrane Library, and Embase. Quality assessment of the included studies was carried out, and the review was structured according to PRISMA. Implant loss and corresponding 3‐ and 5‐year survival rates were estimated by means of a Poisson regression model with total exposure time as offset.

Results

After title, abstract, and full‐text screening, 54 studies were included for qualitative analyses. Estimated 5‐year survival rates of implants were 97.9% [95% CI 97.4; 98.4] in the maxilla and 98.9% [95% CI 98.7; 99.1] in the mandible. Corresponding implant loss rates per 100 implant years were significantly higher in the maxilla (0.42 [95% CI 0.33; 0.53] vs. 0.22 [95% CI 0.17; 0.27]; P = 0.0001). Implant loss rates for fixed restorations were significantly lower compared to removable restorations (0.23 [95% CI 0.18; 0.29] vs. 0.35 [95% CI 0.28; 0.44]; P = 0.0148). Four implants and a fixed restoration in the mandible resulted in significantly higher implant loss rates compared to five or more implants with a fixed restoration. The analysis of one implant and a mandibular overdenture also revealed higher implant loss rates than an overdenture on two implants. The same (lower implant number = higher implant loss rate) applied when comparing 2 vs. 4 implants and a mandibular overdenture. Implant loss rates for maxillary overdentures on <4 implants were significantly higher than for four implants (7.22 [95% CI 5.41; 9.64] vs. 2.31 [1.56; 3.42]; P < 0.0001).

Conclusions

Implant location, type of restoration, and implant number do have an influence on the estimated implant loss rate. Consistent reporting of clinical studies is necessary and high‐quality studies are needed to confirm the present results.

Are there specific indications for the different alveolar bone augmentation procedures for implant placement? A systematic review

Bone resorption following tooth loss often interferes with dental implant placement in a desired position, and requires additional bone augmentation procedures. Many techniques have been described to augment and reconstruct alveolar ridge width and height. The aim of this study was to systemically review whether there is evidence to provide indications for the various bone augmentation procedures based on defect dimension and type. An electronic search of the Medline database and Cochrane library, complemented by a manual search, was performed. Inclusion criteria for partial edentulism were: clinical trials on bone augmentation procedures in preparation or at the time of implant placement, reporting preoperative and postoperative dimensions of the ridge. For edentulous patients, studies were included when providing the data on ridge and defect description, or the amount of augmentation achieved. The search yielded 53 publications for partially edentulous patients and 15 publications for edentulous patients. The literature provides evidence that dehiscence and fenestrations can be treated successfully with guided bone regeneration (GBR) at the time of implant placement (mean implant survival rate (MISR) 92.2%, mean complication rate (MCR) 4.99%). In partially edentulous ridges, when a horizontal defect is present, procedures such as staged GBR (MISR 100%, MCR 11.9%), bone block grafts (MISR 98.4%, MCR 6.3%), and ridge expansion/splitting (MISR 97.4%, MCR 6.8%) have proved to be effective. Vertical defects can be treated with simultaneous and staged GBR (MISR 98.9%, MCR 13.1% and MISR 100%, MCR 6.95%, respectively), bone block grafts (MISR 96.3%, MCR 8.1%), and distraction osteogenesis (MISR 98.2%, MCR 22.4%). In edentulous patients, there is evidence that bone block grafts can be used (MISR 87.75%), and that Le Fort I osteotomies can be applied (MISR 87.9%), but associated with a high complication rate. The objective of extracting specific indications for each procedure could not be fully achieved due to the heterogeneity of the studies available. Further studies on bone augmentation procedures should report precise preoperative and postoperative measurements to enable a more exact analysis of the augmentation procedure, as well as to provide the clinician with the rationale for choosing the most indicated surgical approach.