Placement of dental implants in the maxillary tuberosity: a systematic review

A new classification for pterygomaxillary implants and its related surgical implications: a retrospective cohort study

BACKGROUND

To provide a novel classification for all implants in the maxillary retromolar region to simplify surgical design, reduce surgical risks, and guide clinicians in clinical decision-making.

METHODS

A total of 180 patients with bilateral partial or completely edentulous atrophic posterior maxillae who had received or were scheduled to receive pterygomaxillary implants were included in this study. Cone-beam computed tomography was performed, and the sagittal and coronal images were acquired at 110 kV and 10 mA. The exposure volume was 120 mm in diameter and 80 mm in height. The pterygomaxillary implants were divided into three different types based on the anatomical structures the implants passed through.

RESULTS

The average age of the 180 patients was 69 (range: 39-89) years; 99 were men and 81 were women. All the patients exhibited 360 pterygomaxillary implant sites. However, during mimic implantation, 14 implant sites were excluded due to severe resorption of the tuberosity, very small pterygoid plates, or variations in the descending palatal artery configuration. Of the 346 pterygomaxillary implant sites, 24.0% (83/346), 40.7% (141/346), 22.0% (76/346), and 13.3% (46/346) were classified as Types I, IIa, IIb, and III, respectively.

CONCLUSIONS

Type II pterygomaxillary implants were the most commonly used in the novel classification. Different types of pterygomaxillary implants should follow specific designs and surgical strategies to achieve optimal outcomes.

Clinical achievements of implantology in the pterygoid region: A systematic review and meta-analysis of the literature

The purpose of the study is to evaluate the survival rate of pterygoid implants compared to implants placed in different maxilla area and to settle as an alternative solution for the rehabilitation of the posterior maxilla atrophy. Studies that were included for this systematic review were selected using different database of references: PubMed Medline, Lilacs and Cochrane Library. Other journal platforms were also used for the research. Five articles met the strict inclusion/exclusion criteria of the 180 articles founded. This systematic review was registered on Prospero (CRD42023409706) and followed PRISMA statement. A total of 768 implants placed presented 97.43 % with a peak of 100 % of survival rate. Follow-up period varies from a minimum of 1 year to a maximum of six years. Pterygoid implants could be a valid alternative in patients presenting a posterior maxilla atrophy, but results should be interpreted cautiously due to the difficulty of the surgical technique. Further studies in the future should be taken in consideration to confirm the success rate of pterygoid implants since there is only one prospective RCT, potentially incorporating modern technologies such as guided surgery or navigated surgery could be a solution for the success of pterygoid implants, minimizing the risk and less dependent on the operator.

A New Full Digital Workflow for Fixed Prosthetic Rehabilitation of Full-Arch Edentulism Using the All-on-4 Concept

(1) Background: Recent digital workflows are being developed for full-arch rehabilitations supported by implants with immediate function. The purpose of this case series is to describe a new digital workflow for the All-on-4 concept. (2) Methods: The patients were rehabilitated using the All-on-4 concept with a digital workflow including computerized tomography scanning, intra-oral scanning, and CAD-CAM production of the temporary prosthesis, with the 3D printing of stackable guides (base guide, implant guide, and prosthetic guide). The passive fit of the prostheses and the time to perform the rehabilitations were evaluated. (3) Results: The digital workflow allowed for predictable bone reduction, the insertion of implants with immediate function, and the connection of an implant-supported prosthesis with immediate loading. The time registered to perform the full-arch rehabilitations (implant insertion, abutment connection, prosthesis connection) was below 2 hours and 30 min. No passive fit issues were noted. (4) Conclusions: within the limitation of this case series, the digital workflow applied to the All-on-4 concept using stackable base-, implant-, and prosthetic guides constitutes a potential alternative with decreased time for the procedure without prejudice of the outcome.

Outcomes that may affect implant and prosthesis survival and complications in maxillary fixed prosthesis supported by four or six implants: A systematic review and meta-analysis

Objective

To investigate whether the clinical and radiographical outcomes are affected when four or six implants support the maxillary fixed complete denture (FCD).

Materials and methods

This study was registered on PROSPERO (CRD42021226432) and followed the PRISMA guidelines. The focused PICO question was, "For an edentulous maxillary patient rehabilitated with an implant-supported fixed prosthesis, do the clinical and radiographical outcomes differ when four or six implants support the prosthesis ". A thorough search of the relevant studies was designed and performed electronically. The survival rate of implant and prosthesis, marginal bone loss, and complications (mechanical and biological) were the primary outcomes, whereas implant distribution and using the surgical guide, follow-up, and framework material were evaluated as secondary outcomes.

Results

Out of 1099 articles initially retrieved, 53 clearly stated the outcomes of interest and were included in this study. There were no significant differences in implant and prosthesis survival, technical/mechanical complications, and biological complications between the 4-implant group (4-IG) and the 6-implant group (6-IG). However, marginal bone loss (MBL) was significantly higher in the 4-IG (p < 0.01). The surgical guide and follow-up period did not significantly affect implant/prosthesis survival. Additionally, using the CAD/CAM milled framework and anteroposterior implant distribution were associated with significantly higher implant survival in the 6-IG (p < 0.01).

Conclusion

The findings of this study indicated that having a greater number of implants, as seen in the 6-implant group, can lead to a decrease in technical and biological complications and reduce marginal bone loss. It is worth noting that factors such as using CAD/CAM frameworks and the anteroposterior distribution of implants were recognized as important in improving implant survival rates when more implants are present.

Clinical and patient-centered outcomes following rehabilitation of atrophic edentulous maxilla using six implants placed simultaneously with bilateral maxillary sinus augmentation: A retrospective case series

OBJECTIVES

To evaluate treatment success, patient satisfaction, and oral health-related quality of life (OHRQoL) after rehabilitation of atrophic edentulous maxilla (AEM) with six implants placed simultaneously with bilateral maxillary sinus floor augmentation (MSFA).

MATERIALS AND METHODS

The selected patients were fully edentulous with atrophic maxillary posterior residual ridges and rehabilitated with six implants placed simultaneously with bilateral MSFA and immediate All-on-4 provisional fixed prosthesis (PFP). After 7-12 months of implant surgery, all patients have received an All-on-6 definitive fixed prosthesis (DFP). After at least one year of function with DFP, clinical and radiographic examinations were performed. Patient satisfaction was assessed through a visual analog scale (VAS). The OHRQoL before treatment (T0), during provisional (T1), and after definitive prosthesis (T2) was evaluated using OHI-14.

RESULTS

20 maxillary edentulous patients were rehabilitated with 120 implants, 20 immediate All-on-4 PFP, and 20 All-on-6 DFP. Of those, 12 patients have passed at least a year follow-up after DFP insertion and were eligible to be included in the assessment of treatment success. After a mean of 20 (12-36) months follow-up, the implant and prosthesis survival rates were 100%. The success rate at the implant level was 98.6%. The mean marginal bone loss (MBL) was 0.09 ± 0.06 mm. No prosthetic or postoperative complications, and the mean general satisfaction was (91.75 ± 7.06). There was a significant improvement in all OHIP-14 domains during the final All-on-6 prosthesis (T2) (P < 0.01).

CONCLUSIONS

Rehabilitation of atrophic edentulous maxilla using six implants with simultaneous bilateral MSFA and immediate All-on-4 PFP is a successful treatment approach associated with minimal postoperative complications and significant improvement in OHRQoL.

Pterygoid and tuberosity implants in the atrophic posterior maxilla: A retrospective cohort study

STATEMENT OF PROBLEM

Rehabilitation of the partially or completely edentulous posterior maxilla using dental implants is a clinical challenge because of the presence of the maxillary sinus, as well as the low quality and quantity of bone in that region. In addition to bone augmentation procedures, posterior maxillary rehabilitation using implants includes their anchoring in bones such as the zygoma, pterygoid, and maxillary tuberosity, as well as in short implants. However, the performance of pterygoid and tuberosity implants in the atrophic posterior maxilla is unclear.

PURPOSE

The purpose of this retrospective cohort study was to evaluate the survival of tuberosity and pterygoid implants in patients with posterior maxillary atrophy.

MATERIAL AND METHODS

A nonprobability convenient sample of patients who had received fixed prostheses on implants placed in the maxillary tuberosity or pterygoid regions was analyzed retrospectively. Demographic variables included sex (male, female) and age. Implant-related variables included surface characteristics, site of placement, implant design, length, diameter, and anteroposterior insertion angle. Prosthetic-related variables included the type of reconstruction for rehabilitation and loading protocols. Implant survival, complications, crestal bone loss, and follow-up intervals were also documented. Collected data were analyzed at both patient and implant levels. The demographics and implant characteristics of patients receiving pterygoid or tuberosity implants were analyzed with a statistical software program (α=.05). Survival analysis was estimated by using the nonparametric Kaplan-Meier curve.

RESULTS

A total of 119 patients had 183 pterygoid or tuberosity implants inserted. Most implants in the pterygoid region (71.5%) were Ø4.1 mm (87.4%) and 15 mm in length (60.1%). The most common prostheses were complete maxillary reconstructions (49.2%) with late loading (74.3%). The average implant anteroposterior insertion angle was 60.8 degrees. The cumulative survival rate was 97.3% (n=178) during the mean follow-up period of 57 months (range 1 to 168 months). Among all implants placed, 2.7% failed (n=5) within 2 months of their placement. The statistically significant differences noted between tuberosity and pterygoid implants were related to design, surface characteristics, and loading. The average crestal bone loss was 1.5 mm.

CONCLUSIONS

The survival of the implants placed in the maxillary tuberosity and pterygoid regions was high in patients with posterior maxillary atrophy.

Histomorphometric Evaluation of Bone-Guided Regeneration in Maxillary Sinus Floor Augmentation Using Nano-Hydroxyapatite/Beta-Tricalcium Phosphate Composite Biomaterial: A Case Report

Background

The development of techniques in biomaterials design and production added to advanced surgical procedures which enabled better and more predictable clinical outcomes. Maxillary sinus floor augmentation (MSFA) is among the more studied bone-guided regeneration procedure in the literature. The MSFA could be considered the gold standard procedure for bone-guided regeneration as it provides suitable functional and aesthetic solutions to alveolar ridge atrophy due to tooth loss.

Purpose

This study aimed to conduct a detailed histomorphometric evaluation of collagen production in SFAs bone-guided regeneration, using nano-hydroxyapatite/ß-tricalcium phosphate (nano-HA/ß-TCP) composite.

Patients and Methods

A 52-year-old female had the left upper second premolar condemned due to periodontal disease, then a tooth implant replacement was planned. Due to maxillary sinus pneumatization, the MSFA had to be done before implant placement. Nano-HA/ß-TCP composite (2g) was used in the MSFA procedure. After nine months of the healing process, during the Cone Morse implant installation process, bone samples were collected for histologic analysis (sirius red, hematoxylin/eosin, polarized microscopy). Six months after implant installation, a ceramic crown was installed according to the patient’s request.

Results

Proper masticatory function and aesthetics were re-established. The histomorphometric evaluation indicated that nano-HA/ß-TCP composite did not show any area devoid of cellular activity in sirius red or hematoxylin/eosin staining and the percentage (%) of new bone collagen fibers was achieved using polarization technique evaluation.

Conclusion

According to these results, nano-HA/ß-TCP composite presented clinical and histomorphometric properties suit to be used as bone-guided regeneration biomaterial in MSFA. Furthermore, nano-HA/β-TCP composite provided a favorable nano-environment to bone cells, enhancing bone matrix production.

Clinical, radiographic and restorative parameters for short tuberosity implants placed in smokers: a retrospective study with 5 year follow-up

This study aimed to estimate and compare the clinical, radiographic, and restorative parameters around short tuberosity implants (STIs) placed in cigarette smokers (CS) and never smokers (NS). In this 60-month follow-up retrospective study, a total of 50 (37 males + 13 females) individuals who had received 82 dental implants were included. These participants were categorized into two groups as follows: (i) Group-1: 25 self-reported systemically healthy CS with 43 STIs; and (ii) Group-2: 25 self-reported systemically healthy NS with 39 STIs. In both groups, peri-implant plaque index (PI), probing depth (PD), bleeding on probing (BOP), and crestal bone loss (CBL) and restorative parameters were measured at 12 and 60 months of follow-up. Group comparisons were performed utilizing the Kruskal-Wallis test. The significance level was set at p < 0.05. In CS and NS, the mean age of participants was 58.5 and 60.7 years, respectively. No statistically significant differences were observed in the overall mean levels of PD and CBL around STIs among CS and NS. However, a statistically significant increase was observed in the mean scores of BOP and PI around STIs in the NS and CS at 12 and 60 months follow-up, respectively. In both groups, the loosening of the implant was the most frequently encountered type of STI failure. The outcomes of the present study suggest that STIs placed in maxillary tuberosity can show reliable clinical, radiographic, and restorative stability among cigarettes smokers and non-smokers. However, the role of smoking status and oral hygiene cannot be disregarded in this scenario.

Computed tomography assessment of maxillary bone density for orthodontic mini-implant placement with respect to vertical growth patterns

OBJECTIVE

To quantitatively measure and report bone density of maxilla in the interradicular (alveolar and basal bone) and infrazygomatic crest (IZC) region in various growth patterns among Dravidian individuals.

DESIGN

This was a retrospective spiral computed tomography (CT) study.

SETTING

The study was conducted at the Department of Orthodontics, Saveetha Dental College and Hospital, Tamil Nadu, India.

METHODS

Sixty CT scans (24 men, 36 women; mean age = 25.3 years and 23.8 years, respectively) divided equally into three groups based on vertical facial proportions were included. Bone density measurements in Hounsfield units (HU) were performed using Philips and RadiAnt DICOM viewers. Buccal cortical, palatal cortical and cancellous bone regions were analysed in a Philips DICOM viewer and IZC region was analysed in a RadiAnt DICOM viewer. Statistical analysis with one-way ANOVA and post-hoc Tukey HSD test was done.

RESULTS

The hypodivergent group had a significantly higher bone density at the buccal cortex in posterior region (P < 0.05) when compared to the normodivergent and hyperdivergent groups. Buccal basal bone was denser than buccal alveolar bone (P < 0.05) in all three groups. In the IZC region, hypodivergent groups had significantly higher density values when compared to the normodivergent and hyperdivergent groups (P < 0.05).

CONCLUSION

The present study concluded that cancellous bone density in the interradicular regions was greatest in the anterior sites and was not influenced by growth pattern. Hypodivergent groups tend to have higher density in the posterior regions (buccal and palatal cortical bone) and at the IZC region compared to normodivergent and hyperdivergent groups.

Closed versus open reduction of facial fractures in children and adolescents: A systematic review and meta-analysis

BACKGROUND

Treatment of facial fractures in children and adolescents has always been a challenge for oral surgeon. The choice of treatment type must take into account several factors. This systematic review aimed to evaluate closed versus open reduction of facial fractures for pediatric facial fractures.

MATERIAL AND METHODS

A systematic review of the literature was conducted in three databases (PubMed/MEDLINE, Embase and The Cochrane Library) in accordance with the PRISMA statement. The PICO question was: Conservative treatment is more appropriate than surgical treatment for reducing facial fractures in children and adolescents? The full papers of 41 references were analyzed in detail. Eleven papers were included in this systematic review: one prospective study and ten retrospective studies. All studies evaluated the complication rate.

RESULTS

A total of 73 (7.68%) of the 950 patients experienced complications. Among these patients, 24 (3.85%) had been treated with conservative treatment and 49 (15.03%) with surgical treatment. The fixed-effects model revealed a lower complication rate with conservative treatment than surgical treatment (P<0.00001; RR: 0.18; 95% CI: 0.11-0.28). Heterogeneity was low for the complication rate outcome (X2: 5.64; P = 0.69; I2: 0%).

CONCLUSIONS

The present findings show that conservative treatment is more commonly performed for pediatric facial fractures and complications occur more with surgical treatment. Therefore, surgeons must evaluate all variables involved in choosing the most appropriate treatment method to ensure greater benefits to the patient with fewer complications. Key words:Closed fracture reduction, open fracture reduction, pediatrics, treatment failure.

Failure rates of miniscrews inserted in the maxillary tuberosity

Introduction:

Anchorage conservation in orthodontics has always been a challenge.

Objective:

The aim of this current study was to find out the failure rate of miniscrews inserted in the maxillary tuberosity (MT) region.

Methods:

This pilot study consisted of 40 patients (23 female, 17 male; mean age = 20.1±8.9 years) that had received 60 MT miniscrews for orthodontic treatment. Clinical notes and pictures were used to find out the primary outcome of miniscrew failure. Independent failure factors were also investigated. Logistic regression analysis was done for predictor’s relation with MT miniscrews failure.

Results:

There was no significant correlation in failure rate according to various predictor variables, except for miniscrews installed by lesser experienced operators, which showed significantly more failure. The odds ratio for miniscrew failure placed by inexperienced operators was 4.16.

Conclusion:

A 26.3% failure rate of mini-implants inserted in the MT region was observed.

Clinical outcomes of pterygoid implants: Systematic review and meta-analysis

The aim of this systematic literature review was to analyze clinical outcomes of pterygoid implant for the treatment of patients with atrophic posterior maxillae and to provide clinical recommendations for this dental implant technique. An extensive search of electronic databases (PubMed/Medline, Science Direct, Lilacs, Embase, and Cochrane Library) was conducted, for articles published between January 1995 and January 2018, to identify literature presenting clinical outcomes of pterygoid implants in the treatment of patients with atrophic posterior maxillae. The systematic review was performed in accordance with PRISMA/PICO statement guidelines, and the risk of bias was assessed (Australian National Health and Medical Research Council scale). The relative risk of implant failure was analyzed within a 95% confidence interval (95% CI). After screening 331 abstracts from the electronic databases, 36 full-text articles were accessed for eligibility, and a total of 6 studies were included in this systematic review (after applying the inclusion and exclusion criteria). All studies were retrospective in nature and were classified with a poor level of evidence. A total of 634 patients received 1.893 pterygoid implants, with a mean implant survival rate of 94.87%. The mean prevalence of implant failure was 0.056 with a 95% CI of 0.04-0.077. This study demonstrates that pterygoid implants can be successfully used in patients with atrophic posterior maxilla. However, the results should be interpreted with caution, given the presence of uncontrolled confounding factors in the included studies.

Anatomical study of the maxillary tuberosity using cone beam computed tomography

OBJECTIVES

To examine the dimensions (width, length, and height) of the maxillary tuberosity (MT) and their correlations with age and sex, and to identify different anatomical types for adequate positioning of miniscrews in this area.

METHODS

The study enrolled 39 patients attending the University of Valencia. The patients comprised 21 males and 18 females with a mean age of 39.7 ± 8.4 years. The dimensions of all 78 MTs were measured on cone beam computed tomography (CBCT) images using Invivo Dental 5 software.

RESULTS

The intraobserver and interobserver errors were good for all measurements. A total of 858 MT measurements were taken. The widths were greater in men than in women, with significant differences. The MT dimensions showed correlations with patient age, whereby older patients presented with greater widths and lengths, but reduced heights. Three different anatomical types were detected according to patient age.

CONCLUSIONS

The dimensions (width, length, and height) of the MT vary according to patient age and sex. The MT dimensions conform to particular anatomical types, which should be taken into account when placing miniscrews in this region.

Influence of different implant-abutment connections on stress distribution in single tilted implants and peripheral bone: A three-dimensional finite element analysis

BACKGROUND

The load transfer between the implant-bone interface depends on various factors, including loading type; material properties of the implant and prosthesis; and implant geometry, length, diameter, and shape.

OBJECTIVE

The purpose of this study was to evaluate stress distribution in single tilted bone-level implants with different connections and peripheral bone under vertical and oblique loads using three-dimensional (3D) finite element analysis (FEA).METHOS.3D models of four different implant systems and their abutments were created from the data (computer-aided design) of original implants and abutments scanned with an optical scanner. The implants were placed in the bone block at degrees of 0°, 15°, and 30°. Then, a 3D model of the metal-ceramic crown was created and a 100-N total load was applied vertically and obliquely.

RESULTS

Stress analyses showed variable results depending on the connection design and tilting angle; however, the tube in tube (TIT) connection type exhibited lower stress values in most loading and tilting simulations.

CONCLUSIONS

Increase in tilting angle showed variable results in each connection design. The TIT connection design was found to be more successful in terms of stress distributions in the implant components and the peripheral bone.

Can Genetic Factors Compromise the Success of Dental Implants? A Systematic Review and Meta-Analysis

Dental implants provide a predictable treatment option for partial and complete edentulism via the placement of a fixed permanent artificial root to support prosthetic dental crowns. Despite the high survival rates, long-term dental implant failures are still reported, leading to implant removals and additional financial and health burdens. While extrinsic factors that improve the success rate of implants have been well explored, the impact of genetic factors on this matter is poorly understood. A systematic review and meta-analysis study was conducted to determine whether genetic factors contribute to an increased risk of dental implant failures. A comprehensive search for peer-reviewed articles on dental implants and genetic factors was performed using various literature database libraries. The study design was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, and the obtained records were registered in the International Prospective Register of Systematic Reviews (PROSPERO) database. According to the exclusion/inclusion criteria, 13 studies were eligible for this study out of 809 articles. The meta-analysis of the combined association studies of DNA variations and dental implants did not indicate an increased risk for implant failure due to DNA variations in IL-1B, IL-10 and TNF-α. This study emphasizes the need for larger randomized controlled clinical trials to inform clinicians and patients about the role of genetic factors on dental implant survival and the success rate in healthy and compromised patients.

Dental implants in patients with osteoporosis: a systematic review with meta-analysis

There is currently no consensus regarding the survival rate of osseointegrated implants in patients with osteoporosis. A systematic review with meta-analysis was performed to evaluate the survival rate of implants in such patients. The PubMed/MEDLINE, Web of Science, Cochrane Library, and SciELO databases were used to identify articles published up to September 2016. The systematic review was performed in accordance with PRISMA/PICO requirements and the risk of bias was assessed (Australian National Health and Medical Research Council scale). The relative risk (RR) of implant failure and mean marginal bone loss were analyzed within a 95% confidence interval (CI). Fifteen studies involving 8859 patients and 29,798 implants were included. The main outcome of the meta-analysis indicated that there was no difference in implant survival rate between patients with and without osteoporosis, either at the implant level (RR 1.39, 95% CI 0.93-2.08; P=0.11) or at the patient level (RR 0.98, 95% CI 0.50-1.89; P=0.94). However, the meta-analysis for the secondary outcome revealed a significant difference in marginal bone loss around implants between patients with and without osteoporosis (0.18mm, 95% CI 0.05-0.30, P=0.005). Data heterogeneity was low. An increase in peri-implant bone loss was observed in the osteoporosis group. Randomized and controlled clinical studies should be conducted to analyze possible biases.

Comparison between piezoelectric surgery and conventional saw in sagittal split osteotomies: a systematic review

A systematic review of the advantages and disadvantages of piezoelectric surgery in comparison with conventional saws for sagittal split osteotomy (SSO) was performed. Relevant studies published in the last 10 years were identified through a search of the PubMed/MEDLINE, Science Direct, and Embase databases and assessed against predetermined eligibility criteria. The initial search resulted in 1736 articles. After applying the inclusion and exclusion criteria, 12 articles remained. A total of 799 patients with an average age of 27.5 years underwent SSO performed using a saw or ultrasonic device. Results showed that it took longer to perform the osteotomies using an ultrasonic device than using a conventional saw. At ≥6 months of follow-up, neurosensory disturbance was seen in 4.7% of patients who underwent piezoelectric surgery versus 61.6% of patients who underwent surgery in which a conventional saw was used. It was found that the use of piezoelectric surgery in SSO leads to the best outcome regarding neurosensory disturbance when compared to conventional saws (P=0.04) at ≥6 months of follow-up. Further studies are required for the evaluation of the other clinical parameters assessed.

Maxillary sinus lift surgery-with or without graft material? A systematic review

The purpose of this systematic review was to perform a comparative analysis of the use or not of graft material in maxillary sinus lift surgery. Relevant studies published in the last 10 years were identified through a search of the PubMed/MEDLINE, ScienceDirect, and Cochrane Library databases and were assessed against the study inclusion and exclusion criteria. The initial search resulted in 1037 articles. After applying the inclusion and exclusion criteria, 16 articles remained. Four hundred and thirty-six patients were followed up over a postoperative period ranging from 6 months to 11 years. In total, 868 implants were installed in 397 maxillary sinuses. The implant survival rate was 96.00% for surgeries performed without graft material and 99.60% for those in which biomaterial was used, within a follow-up period of 48 to 60 months. In conclusion, maxillary sinus lift surgery, with or without graft material, is a safe procedure with a low complication rate and predictable results.

Late mandibular fracture occurring in the postoperative period after third molar removal: systematic review and analysis of 124 cases

Factors associated with the diagnosis, aetiology, and treatment of mandibular fractures occurring during the postoperative period following the removal of a lower third molar are discussed. The following databases were searched using specific key words: PubMed/MEDLINE, LILACS, Embase, and Scopus. The search yielded 124 cases. Sex, age, side, tooth position and angulation, bone impaction, relationship between the tooth and the inferior alveolar nerve, local pathological conditions, aetiology of the fracture, symptomatology, and time between surgery and fracture, as well as any displacement of the fracture and the treatment of the fracture, were evaluated. Data were tabulated and the χ² statistical test was applied (P<0.05). Male patients aged >35 years, with teeth in positions II/III and B/C, complete bony impaction, and local bone-like alterations, were found to have a higher frequency of fracture and pericoronitis (P<0.05). Late fractures generally occurred between the second and fourth postoperative weeks (P<0.05). They were generally not displaced and the typical treatment was the non-surgical approach (P<0.05). It is concluded that the risk of mandibular fracture after extraction is associated with excessive ostectomy and/or local alterations. At-risk patients should be thoroughly briefed on the importance of a proper postoperative diet.

Short dental implants versus standard dental implants placed in the posterior jaws: A systematic review and meta-analysis

OBJECTIVE

The purpose of the present systematic review and meta-analysis was to compare short implants (equal or less than 8mm) versus standard implants (larger than 8mm) placed in posterior regions of maxilla and mandible, evaluating survival rates of implants, marginal bone loss, complications and prosthesis failures.

DATA

This review has been registered at PROSPERO under the number CRD42015016588. Main search terms were used in combination: dental implant, short implant, short dental implants, short dental implants posterior, short dental implants maxilla, and short dental implants mandible.

SOURCE

An electronic search for data published up until September/2015 was undertaken using the PubMed/Medline, Embase and The Cochrane Library databases.

STUDY SELECTION

Eligibility criteria included clinical human studies, randomized controlled trials and/or prospective studies, which evaluated short implants in comparison to standard implants in the same study.

CONCLUSION

The search identified 1460 references, after inclusion criteria 13 studies were assessed for eligibility. A total of 1269 patients, who had received a total of 2631 dental implants. The results showed that there was no significant difference of implants survival (P=.24; RR:1.35; CI: 0.82-2.22), marginal bone loss (P=.06; MD: -0.20; CI: -0.41 to 0.00), complications (P=.08; RR:0.54; CI: 0.27-1.09) and prosthesis failures (P=.92; RR:0.96; CI: 0.44-2.09). Short implants are considered a predictable treatment for posterior jaws. However, short implants with length less than 8 mm (4-7 mm) should be used with caution because they present greater risks to failures compared to standard implants.

CLINICAL SIGNIFICANCE

Short implants are frequently placed in the posterior area in order to avoid complementary surgical procedures. However, clinicians need to be aware that short implants with length less than 8mm present greater risk of failures.

Effects of platelet-rich plasma in association with bone grafts in maxillary sinus augmentation: a systematic review and meta-analysis

This systematic review evaluated the effect on bone formation and implant survival of combining platelet-rich plasma (PRP) with bone grafts in maxillary augmentation. A comprehensive review of articles listed in the PubMed/MEDLINE, Embase, and Cochrane Library databases covering the period January 2000 to January 2015 was performed. The meta-analysis was based on bone formation for which the mean difference (MD, in millimetres) was calculated. Implant survival was assessed as a dichotomous outcome and evaluated using the risk ratio (RR) with 95% confidence interval (CI). The search identified 3303 references. After inclusion and exclusion criteria were applied, 17 studies were selected for qualitative analysis and 13 for quantitative analysis. A total of 369 patients (mean age 51.67 years) and 621 maxillary sinus augmentations were evaluated. After the data analysis, additional analyses were performed of the implant stability quotient, marginal bone loss, and alveolar bone height measured by MD. The results showed no significant difference in implant stability (P=0.32, MD 1.00, 95% CI -0.98 to 2.98), marginal bone loss (P=0.31, MD 0.06, 95% CI -0.05 to 0.16), alveolar bone height (P=0.10, MD -0.72, 95% CI -1.59 to 0.14), implant survival (P=0.22, RR 1.95, 95% CI 0.67-5.69), or bone formation (P=0.81, MD -0.63, 95% CI -5.91 to 4.65). In conclusion, the meta-analysis indicates no influence of PRP with bone graft on bone formation and implant survival in maxillary sinus augmentation.

Evaluation of cement-retained versus screw-retained implant-supported restorations for marginal bone loss: A systematic review and meta-analysis

STATEMENT OF PROBLEM

No consensus has been reached on which retention system, cement- or screw-retained, is best to avoid bone loss around the implant of a fixed implant-supported restoration.

PURPOSE

The purpose of this systematic review and meta-analysis was to compare cement- and screw-retained retention systems in fixed implant-supported restorations in terms of marginal bone loss, implant survival, and prosthetic complications.

MATERIAL AND METHODS

A comprehensive search of studies published from January 1995 to March 2015 and listed in the PubMed/MEDLINE, Embase, Scopus and the Cochrane Library databases was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The meta-analysis was based on the Mantel-Haenszel and inverse variance methods. Marginal bone loss was the continuous outcome measure evaluated by mean difference (MD), and implant survival and prosthetic complications were the dichotomous outcome measures evaluated by risk ratio (RR), both with corresponding 95% confidence intervals (CI).

RESULTS

The 20 studies selected for review evaluated 2139 participants, whose mean age was 47.14 years and who had received 8989 dental implants. The mean follow-up was 65.4 months (range: 12-180 months). Results of the MD for marginal bone loss showed statistically significant differences in favor of the cement-retained prosthesis (P =.04; MD: -0.19; CI: -0.37 to -0.01). The implant survival rate was higher for the cement-retained prosthesis (P =.01; RR: 0.49; CI: 0.28 to 0.85), and the prosthetic complication rate was higher for the screw-retained prosthesis (P =.04; RR: 0.52; CI: 0.28 to 0.98). Additional analysis of the mean plaque index did not show differences between retention systems (P=.58; MD: 0.13; CI: -0.32 to 0.57).

CONCLUSIONS

The current meta-analysis indicated that cement-retained, fixed implant-supported restorations showed less marginal bone loss than screw-retained, fixed implant-supported restorations during the follow-up period, which ranged from 12 to 180 months. However, the small difference between the mean values may not show clinical significance. The rates of prosthetic complication and implant survival also compared favorably with cement-retained prostheses.