Peri-implantitis and maxillary sinus membrane thickening: A retrospective cohort study.

OBJECTIVE: The objective of this study is to investigate the association of peri-implantitis (PI) and sinus membrane thickening and to assess the resolution of membrane thickening following intervention (implant removal or peri-implantitis treatment) aimed at arresting PI. MATERIALS AND METHODS: Forty-five patients with 61 implants in the posterior maxillary region were retrospectively included in the study. Twenty-four patients were diagnosed with peri-implantitis (PI) and 21 had peri-implant health (PH). Cone-beam computed tomography (CBCT) scans were evaluated to assess maxillary sinus characteristics, including membrane thickening, sinus occupancy and ostium patency. The CBCT scans taken 6 months after intervention aimed at arresting disease (implant removal or treatment of PI) in the PI group were also appraised and compared to baseline scans. RESULTS: At baseline, all parameters evaluating membrane thickness disorders yielded significant differences between groups (p < .001). Patients with posterior maxillary implants diagnosed with PI were 7× more likely to present membrane thickening compatible with pathology when compared to patients with healthy implants (OR = 7.14; p = .005). Furthermore, the likelihood was 6x greater in implants diagnosed with PI to exhibit moderate membrane thickening (OR = 6.75, p = .001). The patients receiving interventions aimed at arresting PI experienced significant enhancement in all radiographic parameters related to the sinus cavity at the 6-month follow-up (p < .001), though these variations were similarly independent of whether treatment consisted of PI treatment or implant removal. CONCLUSIONS: Maxillary sinus membrane thickening and the permeability/obstruction of the ostium are frequently associated with the presence of PI in posterior implants. Interventions targeting disease resolution effectively reduce membrane thickness to levels compatible with maxillary sinus health.

Ultrasound-Guided Suprazygomatic Maxillary Nerve Block Is Effective in Reducing Postoperative Opioid Use Following Bimaxillary Osteotomy.

BACKGROUND: Ultrasound-guided maxillary nerve block has recently been described, though its impact upon bimaxillary osteotomy has not been formally investigated. PURPOSE: The present study was carried out to determine whether the addition of ultrasound-guided maxillary nerve block in subjects undergoing bimaxillary osteotomy reduces opioid use. STUDY DESIGN, SETTING, SAMPLE: A randomized clinical trial was carried out in adults undergoing bimaxillary osteotomy between April 2019 and January 2020 at Teknon Medical Center (Barcelona, Spain). PREDICTOR VARIABLE: The predictor variable was the treatment technique used (maxillary nerve block or no block). The subjects were randomized to either receive (test group) or not receive (control group) bilateral ultrasound-guided suprazygomatic maxillary nerve block (5 ml of 0.37% ropivacaine) before surgery. MAIN OUTCOME VARIABLE(S): The primary outcome variable was the intravenous methadone requirements in the first two postoperative hours. The secondary outcome variables were postoperative pain, rescue subcutaneous methadone, intravenous remifentanil used intraoperatively, the incidence of postoperative nausea-vomiting, and complications derived from maxillary nerve block. COVARIATES: Subject age, sex, weight, height, and anesthetic risk, and the duration of surgery were recorded. ANALYSES: Descriptive and inferential analyses were performed using the χ2 test and Mann-Whitney U test. Statistical significance was considered for P < .05. RESULTS: The baseline sample consisted of 68 subjects scheduled for bimaxillary osteotomy. The follow-up sample comprised 60 subjects: 30 in the control group (10 females and 20 males, aged 34.0 ± 10.2 years) and 30 in the test group (13 females and 17 males, aged 29.8 ± 10.8 years). The subjects who received maxillary nerve block showed less intravenous methadone use in the first 2 hours postsurgery (median 2.0 mg control group vs 0 mg test group; P < .001), lower pain levels at any time during the first 18 hours postsurgery (median visual analog score 4 control group vs 2 test group; P < .001), and a lesser percentage required methadone (33.3% control group vs 0% test group; P < .01) at 4-18 hours postsurgery. CONCLUSION AND RELEVANCE: The results obtained suggest that ultrasound-guided maxillary nerve block is a promising anesthetic technique capable of reducing intraoperative and postoperative opioid use, with greater patient comfort in bimaxillary osteotomy.

Surgery-first in interdisciplinary class II cases.

OBJECTIVES: To present an interdisciplinary case treated with a surgery-first orthognathic approach, followed by orthodontic and prosthodontic treatment. CLINICAL CONSIDERATIONS: After an accurate pre-operative virtual planning, a young patient with skeletal class II, retrognathia, and an anterior open bite was treated with bimaxillary orthognathic surgery without pre-surgical orthodontic decompensation. Orthodontic treatment was carried out post-operatively. The treatment was completed with a prosthodontic phase to improve the final esthetic outcome of the smile. CONCLUSIONS: A surgery-first approach allowed to achieve esthetic and functional results in a reduced treatment duration that remained stable over the course of 1 year. The outcomes were consistent with prior research in terms of advantages brought by following an accurately planned surgery-first protocol. Nevertheless, longer-term follow-up was required to evaluate the treatment stability. CLINICAL SIGNIFICANCE: An accurately planned surgery-first approach significantly helped in shortening the duration of the treatment, while providing a stable, functional, and esthetic solution to the patient's problems.

Does Aesthetic Osseous Genioplasty Impact Upper Airway Volume?

BACKGROUND: Although maxillomandibular advancement is the treatment of choice for obstructive sleep apnea syndrome (OSAS) in the presence of underlying maxillomandibular complex hypoplasia, there is still a gap in the literature regarding the impact of genioplasty upon upper airway volume (UAV). OBJECTIVES: The aim of this study was to evaluate the impact of isolated osseous genioplasty upon UAV. METHODS: A retrospective analysis of all patients subjected to isolated osseous genioplasty between July 2015 and July 2022 was conducted. Cone-beam computed tomography was performed preoperatively and postoperatively to assess the chin and hyoid 3-dimensional (3D) spatial position and UAV changes after surgery. RESULTS: A total of 44 patients were included in the study. Regarding surgical movements of the chin, almost all patients received a sagittal movement (n = 42; 39 forward and 3 backward), while in 8 patients a vertical movement (5 upward and 3 downward) was applied, and in 6 patients the chin was centered. Statistically significant increases in total UAV (P = .014) and at the level of the oropharynx (P = .004) were observed. Specifically, chin centering, upward and forward movements enlarged the oropharynx volume (P = .006, .043 and .065, respectively). Chin advancement enlarged the hypopharynx volume (P = .032), as did upward movement of the hyoid bone (P < .001). CONCLUSIONS: Results of the study suggest that aesthetic osseous genioplasty impacts the UAV: each 3D spatial chin movement differently impacts the upper airway by enlarging or narrowing it. However, further studies addressing the apnea-hypopnea index are required to assess its effectiveness in treating OSAS.

Narrow diameter titanium-zirconium tissue-level implants supporting multi-unit FDPs in the anterior area: A 5-year prospective study.

BACKGROUND: Narrow diameter implants (NDIs) are used in cases of limited mesio-distal space, or if the alveolar ridge does not allow placement of a standard diameter implant. PURPOSE: The aim of this prospective case series study is to present the 5-year clinical-, radiological-, and patient-reported outcome measures (PROMs) of patients with partial edentulism in the anterior area of the jaws requiring the placement of two narrow diameter implants to support a 3- or 4-unit fixed partial denture (FPD). MATERIALS AND METHODS: Thirty partially edentulous patients missing 3 or 4 adjacent teeth in the anterior area of the jaws were included in the study. Two titanium-zirconium tissue-level NDIs were placed in each patient in healed anterior sites (60 implants). A conventional loading protocol was performed to provide a FPD. Implant survival, success, marginal bone-level changes (MBL), clinical parameters, buccal bone stability with CBCT, adverse events and PROMs were recorded. RESULTS: The survival and success rates for the implants were 100%. The mean MBL (±SD) after prosthesis delivery, and 5-year follow-up (mean 58.8 months; range: 36-60) was 0.12 ± 0.22 and 0.52 ± 0.46 mm, respectively. Decementation and screw loosening were the most frequent prosthetic complications, yielding a prosthetic survival and success rates of 100% and 80%, respectively. Patient satisfaction was high with a mean (±SD) score of 89.6 ± 15.1. CONCLUSIONS: The use of tissue-level titanium-zirconium NDIs supporting splinted multi-unit FPDs in the anterior area seems to be a safe and predictable treatment option after a 5-year follow-up period.

Definition of New Three-Dimensional Cephalometric Analysis of Maxillomandibular Sagittal Relationship for Orthodontics and Orthognathic Surgery: Normative Data Based on 700 CBCT Scans.

The objective of the study was to define the norm of new 3-dimensional cephalometric analysis of maxillomandibular sagittal relationship with the patient in Natural Head Position. A cross-sectional study was performed using 700 consecutives cone beam computed tomography datasets of pre-orthodontic patients received for three-dimensional craniofacial analysis. To stablish the clinical norm of the new sagittal reference (linear distance A-B), the correlation with the gold standard (ANB angle) was estimated with the Pearson's correlation coefficient. Subsequently, the prognostic values of the linear distance A-B was calculated to define the clinical norm. The sample was composed by 463 women (66.1%) and 237 men (33.9%). The mean age was 30 ± 14,5 years old (range 6-71 y old). According to the skeletal class classification (ANB), 46.1% (323) were class I, 42% (294) class II, and 11.9% (83) class III. The regression model found that each additional grade of the ANB angle imply a mean increase of 1.24 mm of the distance A-B ( P <0.001). The normative value of the linear distance A-B was obtained through the prognostic values of the distance for the limits of the ANB norm 0 to 4. These values were on the range of 0.52 to 5.48 mm. Therefore, the clinical norm for cephalometric maxillomandibular sagittal relationship using linear distance from point A-B is: 3±2.48 mm. With this new approach, we can define the skeletal sagittal relationship of the patient in natural head position overcoming the limitations of using intracranial or occlusal plane references improving the diagnosis and orthognathic surgical planning process.

Accuracy of static fully guided implant placement in the posterior area of partially edentulous jaws: a cohort prospective study.

OBJECTIVE: A cohort prospective study was conducted to assess the three-dimensional positioning accuracy of the implant between pre-surgical and the final implant position using a static fully guided approach in the posterior area of the jaws. MATERIALS AND METHODS: A total of 60 implants (30 patients) were digitally analyzed after superimposing the Digital Imaging and Communications in Medicine (DICOM) files obtained from the Cone Beam Computed Tomography (CBCT) pre- and post-implant placement. The software calculations included deviations at the implant shoulder and at the implant apex, global deviation (3D offset), and angle deviation. Statistical analysis was performed with α = 0.05. RESULTS: Considering the total number of implants, mesiodistal, buccolingual, and apicocoronal mean deviations at the shoulder and implant apex were equal or below 0.21 ± 0.69 mm, and only the buccolingual mean deviation at the apex reached up to 0.67 ± 1.06 mm. The mesiodistal and apicocoronal deviations were not statistically significant at both the shoulder and apex levels of the implant. The mean total angular deviation was 5.62° ± 4.09. The main limitation of this surgical approach was the requirement for a wide mouth opening. CONCLUSIONS: Static fully guided surgery for dental implant placement exhibits minimum deviations respect to presurgical planning. The main limitation in the posterior areas is the requirement for a wide mouth opening. CLINICAL RELEVANCE: Even with minimum deviations clinically acceptable, precautions and safety margins must be respected when using static full-guided surgery to place dental implants.

Accuracy of dynamic implant navigation surgery performed by a novice operator.

AIM: The main objective was to evaluate the accuracy of dynamic navigation-guided surgery (DNGS) for implant positioning performed by a novice operator. The secondary objectives were to analyze the operator's learning curve and identify possible complications deriving from the technique. MATERIALS AND METHODS: Twenty-five implants were placed in eight partially edentulous human heads. Preoperative CBCT scans were imported to planning software to determine the implant positions. Implants were placed using a dynamic navigation system. Postoperative CBCTs were superimposed onto the implant planning images. Discrepancies between the virtually planned implant positions and the postoperative positions were evaluated by measuring horizontal platform deviation, apex deviation, apicocoronal (vertical) deviation, and angular deviation. RESULTS: Mean platform, apex, vertical, and angle deviations were 1.55 ± 0.81 mm, 2.45 ± 0.84 mm, 1.59 ± 0.70 mm, and 5.56 ± 4.03 degrees, respectively. No significant differences were found between the maxilla and mandible or between anterior and posterior sites. A flat learning curve was observed, with the exception of the implant platform, where a tendency toward improvement in accuracy was observed between the 8th and the 17th implant placed. No complications were reported. CONCLUSIONS: Based on the results of a study performed by a novice operator on a cadaveric model, DNGS allows accurate implant placement within a 2-mm safety margin in terms of implant platform and vertical positions, and a 3-mm margin in apical vicinities. The technique requires practice to learn the required eye-hand coordination. (Int J Comput Dent 2022;25(4):377-0; doi: 10.3290/j.ijcd.b2588207).

Intra-osseous heat generation during implant bed preparation with static navigation: Multi-factor in vitro study.

OBJECTIVES: To compare the intra-osseous temperature reached during bone drilling for dental implant placement using open versus closed static surgical guides and evaluate the influence of bone density, osteotomy drilling depth, and irrigation fluid temperature. MATERIAL AND METHODS: 960 osteotomies were performed with 2 mm pilot drills in 16 solid rigid polyurethane foam blocks. Two main variables were considered: the guide type (open or closed guide) and bone density (hard (D1) or soft (D4). The blocks were divided into four groups according to the type of surgical template and bone density as follows: group one: closed guide and hard bone; group two: open guide and hard bone; group three: closed guide and soft bone; and group four: open guide and soft bone. A combination of different experimental conditions was used, including different bone osteotomy depths (6 or 13 mm) and irrigation fluid temperatures (5°C or 21°C). RESULTS: The highest mean temperature was found in group one (28.29 ± 4.02°C). In the soft bone groups (three and four), the mean maximum temperature decreased compared to groups one and two (dense bone) and was always higher with closed guides (23.38 ± 1.92°C) compared to open guides (21.97 ± 1.22°C) (p < .001). The osteotomy depth and irrigation fluid temperature also significantly influenced the bone temperature (p < .001), especially in hard bone. CONCLUSIONS: The greatest heat generation was observed in high-density bone. The final intra-bone temperature was about 1°C higher with a closed static surgical guide than with an open guide. The heat generation in osteotomy sites was substantially reduced by cooling the irrigation fluid to 5°C.

What are the Surgical Movements in Orthognathic Surgery That Most Affect the Upper Airways? A Three-Dimensional Analysis.

PURPOSE: Most studies have focused on airway changes after maxillomandibular advancement; however, airway size will change depending on the type, direction, and magnitude of each skeletal movement. The aim of this study was to assess the effect of the maxillary and/or mandibular movements on the pharyngeal airway volume and the minimum cross-sectional area using 3-dimensional cone-beam computed tomography voxel-based superimposition. PATIENTS AND METHODS: The investigators designed and implemented a retrospective cohort study composed of patients with dentofacial deformity subjected to orthognathic surgery. The predictor variables were the surgical movements performed at surgery. The primary outcome variables were the pharyngeal airway volume and minimum cross-sectional area measured preoperatively, at 1- and 12-month follow-up. Skeletal and volumetric relapse and stability were recorded as secondary outcomes at 1 and 12 months, respectively. Descriptive, bivariate and correlation analyses were computed. Significance was set at P < .05. RESULTS: The sample was composed of 103 patients grouped as follows: bimaxillary (53), maxillary (25), or isolated mandible (25). All of the surgical treatments resulted in a significant linear pattern of initial immediate increase of 33.4% (95% confidence interval [CI]: 28.2 to 38.7%; P < .001) in volumetric (nasopharynx [28.7%, CI: 22.7 34.9%; P < .001], oropharynx [36.2%, CI: 29.0 to 43.5%; P < .001], and hypopharynx [31.5%, CI: 25.7 to 37.3%; P < .001]) and minimum cross-sectional area parameters (bimaxillary = 104%, [CI: 87.1 to 122.1%; P < .001], maxillary = 39.5%, [CI: 18.4 to 60.7%; P < .05], and mandible = 65.8%, [CI: 48.1 to 83.6%; P < .05]), followed by a slight downward trend (stabilization) at 12-month follow-up. Airway increase was favored by mandibular advancement (P < .05) and mandibular occlusal plane changes by counterclockwise rotation (P < .05). CONCLUSIONS: The results of this study suggest that there is a favorable effect of orthognathic surgery in the upper airway regardless of the surgical approach, with bimaxillary advancement and mandibular occlusal plane changes by counterclockwise rotation being the most significant contributors.

Influence of bone density, drill diameter, drilling speed, and irrigation on temperature changes during implant osteotomies: an in vitro study.

OBJECTIVE: The aim of this in vitro study was to evaluate the influence of bone type, drill diameter, drilling speed, and irrigation on heat generation while performing osteotomy for dental implants. MATERIALS AND METHODS: Six polyurethane foam blocks simulating type I (dense) and type IV (soft) bone were selected for the study. Each block was subjected to two different experimental conditions for each drill (2- and 3.5-mm diameter): three sub-groups were created: (a) revolutions per minute (50, 100, or 800 rpm) and (b) irrigation (with or without irrigation). RESULTS: In 2-mm drill group, maximum temperature attained was practically identical: 23.73 ± 2.28 °C in the cortical bone and 23.74 ± 2.03 °C in the cancellous bone. For 3.5-mm, groups showed similar results (25.01 ± 1.88 °C for cortical and 24.05 ± 1.94 °C for trabecular bone). In any type of bone, the presence of irrigating fluid helped to control the maximum temperature (p = 0.001). When comparing the 2-mm and 3.5-mm drills, most differences were found at 100 rpm without irrigation (p < 0.001) and at 800 rpm with irrigation (p = 0.001). CONCLUSIONS: Maximum temperature attained was always below the critical threshold that can cause osteonecrosis, showing that both external irrigation with higher drilling speeds and no irrigation with lower speeds were effective methods to avoid excessive heat generation. CLINICAL RELEVANCE: Despite being always below the critical temperature, bone type, drill diameter, drilling speed, and irrigation must be considered temperature-influencing factors during implant osteotomies.

In-House Hybrid Technique for Customization of Guides and Miniplates in Orthognathic Surgery.

The use of customized plates in Orthognathic surgery offers precision in the repositioning of the jaws, according to the virtual planning performed, with the great advantage of avoiding the need for intermediate occlusal splints. However, the conventional customization process takes time to manufacture, present high cost and still involve legal issues with insurance companies. Moreover, a technical disadvantage is that the systems available for customized plates require large incisions, with large detachment of soft tissues for insertion of the guides and plates. The objective of this paper is to present the in-house hybrid technique for customization of guides and miniplates in orthognathic surgery using minimally invasive approaches.

Regeneration of alveolar ridge defects. Consensus report of group 4 of the 15th European Workshop on Periodontology on Bone Regeneration.

BACKGROUND AND AIMS: Bone augmentation procedures to enable dental implant placement are frequently performed. The remit of this working group was to evaluate the current evidence on the efficacy of regenerative measures for the reconstruction of alveolar ridge defects. MATERIAL AND METHODS: The discussions were based on four systematic reviews focusing on lateral bone augmentation with implant placement at a later stage, vertical bone augmentation, reconstructive treatment of peri-implantitis associated defects, and long-term results of lateral window sinus augmentation procedures. RESULTS: A substantial body of evidence supports lateral bone augmentation prior to implant placement as a predictable procedure in order to gain sufficient ridge width for implant placement. Also, vertical ridge augmentation procedures were in many studies shown to be effective in treating deficient alveolar ridges to allow for dental implant placement. However, for both procedures the rate of associated complications was high. The adjunctive benefit of reconstructive measures for the treatment of peri-implantitis-related bone defects has only been assessed in a few RCTs. Meta-analyses demonstrated a benefit with regard to radiographic bone gain but not for clinical outcomes. Lateral window sinus floor augmentation was shown to be a reliable procedure in the long term for the partially and fully edentulous maxilla. CONCLUSIONS: The evaluated bone augmentation procedures were proven to be effective for the reconstruction of alveolar ridge defects. However, some procedures are demanding and bear a higher risk for post-operative complications.

Jawline Contouring Through an Intraoral Approach in the Context of Bilateral Sagittal Split Osteotomy: A Proof-of-Concept Report.

PURPOSE: This report describes a technique to suspend the submandibular space (SS) through an intraoral approach in the context of a bilateral sagittal split osteotomy (BSSO), thus improving the jawline contour and achieving a neck-rejuvenating effect. PATIENTS AND METHODS: A sample of 6 consecutive patients referred for orthognathic surgery who also sought neck rejuvenation and contouring surgery was selected to implement the technique. The following measurements were used to evaluate the procedure: patient satisfaction with a visual analog scale, photographic assessment, additional operative time, and complications related to the procedure. RESULTS: The average patient age was 47 years (range, 38 to 57 yr). Three patients were women and 3 were men. All patients were highly satisfied with the results achieved at the jawline. No surgical complications occurred in any case. There was an average increase of only 5 minutes in total operative time for each side. CONCLUSION: Suspension of the SS through an intraoral approach is an effective, well-tolerated, and technically straightforward method for neck contouring in patients in whom a BSSO procedure is foreseen.

Semi-Automated Three-Dimensional Condylar Reconstruction.

The objective was to validate a semi-automated segmentation method for 3-dimensional (3D) reconstruction of the mandibular condyle from cone beam computed tomography (CBCT) data and illustrate its application in volumetric analysis of the condyle.Ten CBCT datasets were used to validate the proposed semi-automatic method for 3D rendering of mandibular condyles. First, a standardized orientation protocol of the skull was applied. After defining the volume of interest, a grey-scale cut-off value was selected to allow an automatic reconstruction of the condyle's surface. Subsequently, condylar contour was optimized manually. The whole process was repeated twice by 2 independent investigators. Volumetric measurements of the condyle were used as a measure of conformity between both investigators. The reproducibility of condylar volume reconstruction was excellent for intra-examiner measurements (CV = 3.65%, intraclass correlation coefficient = 0.97) and good for inter-examiner measurements (CV = 7.15%, ICC = 0.89). The overall mean time required for the segmentation process was 6.31 + 2.78 minutes. The proposed protocol provides an accurate and reproducible tool for 3D reconstruction of the mandibular condyle using CBCT data. Its implementation will enable adequate follow-up of morphological changes in bone tissue with a Hounsfield unit-based imaging segmentation method.

Cranial Base Superimposition of Cone-Beam Computed Tomography Images: A Voxel-Based Protocol Validation.

OBJECTIVES: The primary objective of the present study was to find the gold-standard accuracy of voxel-based superimposition of cone-beam computed tomography (CBCT) datasets with a protocol developed for the Dolphin Imaging 3D software. The secondary objectives were to analyze reproducibility and efficiency of this protocol. STUDY DESIGN: Twenty-five CBCT datasets of patients with dental implants present were selected. Each Base Volume dataset was duplicated to create a second volume. Subsequently, both volumes were superimposed with a voxel-based protocol consisting of 3 successive steps "Side-by-side Superimposition"; "Overlay Superimposition"; and "Export Orientation to 2nd Volume". The protocol's accuracy was evaluated by measuring the mean distance between the apex of each dental implant on the Base Volume and second volume datasets. Efficiency was given by the mean time needed to complete all superimposition steps. Reproducibility was analyzed by calculating the intraclass correlation coefficients. RESULTS: Mean time needed to complete the protocol was 198 seconds. The protocol had a rotational accuracy of 0.10° to 019° and a translational accuracy of 0.20 to 0.24 mm. Intra-observer and inter-observer reproducibility were 1 and 0.921 to 1, respectively. CONCLUSIONS: The protocol is accurate, precise, reproducible, and efficient. The validation of this method enables unbiased analysis of surgical outcomes based on a single, user-friendly software product that is widely available in academic and clinical settings.

Influence of Implant Position in Implant-Assisted Removable Partial Denture: A Three-Dimensional Finite Element Analysis.

PURPOSE: To determine the ideal position of a dental implant to assist a posterior extended partial removable dental prosthesis (PRDP), through stress values, displacement values, and deformation of periodontal ligament (PDL). MATERIALS AND METHODS: A finite element analysis of different implant positions was analyzed using a 3D mandible model from a human patient. Test models were created: model A (implant in second molar area), model B (implant in the first molar area), and model C (implant in premolar area). A control model without implant support was also created. Overall displacement values, von Mises stress distribution maps, and nonlinear deformations were evaluated. RESULTS: Some differences could be observed between test models. The introduction of an implant in the edentulous area, unlike a conventional removable partial denture without implant support, decreases stress values in the biological structures such as: mandible, tooth, soft tissue, and PDL. Placing the implant in the first molar area resulted in improved displacement values, and reduced maximum stress values at the peri-implant bone area, metal structure, and implant were observed. CONCLUSIONS: Within the limitations of this study we can conclude that placing the implant in the position of the first molar improves biomechanical behavior of implant-assisted PRDPs.

A New Hybrid Technique for Performing a Safer Bilateral Sagittal Split Osteotomy: Combining Reciprocating Saw and Piezoelectric Devices.

The sagittal split osteotomy (SSO) is an indispensable tool in the correction of dentofacial abnormalities. In elective orthognathic surgery, it is important that surgeons inform patients about the risk of complications related to inferior alveolar nerve damage and unfavorable split. The purpose of this article is to describe a novel, hybrid technique to SSO by combining a reciprocating saw and piezoelectric devices with several advantages over traditional "pure" methods (osteotomies performed by reciprocating saw or piezoelectric devices only) in terms of precision, rapidity, easier splitting, and decreased complications related to inferior alveolar nerve damage and bad split with reduced overall morbidity. The level of evidence was Level IV, therapeutic study.

Zygoma Quad Compared With 2 Zygomatic Implants: A Systematic Review and Meta-analysis.

PURPOSE: The aim of this study was to systematically review and compare the survival rates (SRs) of oral rehabilitations performed with 2 zygomatic implants (ZIs) combined with regular implants (RIs) versus 4 ZI. MATERIAL AND METHODS: An electronic search was performed in several databases for articles published in English between 2007 and 2015. Articles reporting human studies were included in this systematic review. RESULTS: The search yielded to a total of 417 studies, of which 6 were included in this study. ZIs SR weighted mean was 98.0% with a 95% confidence interval (CI) of 96.7% to 99.8%. For the control group (2 ZIs + 2 RIs) and the test group (4 ZIs), the implant SR was 98.6% and 97.4%, respectively, with a 95% CI. No statistically significant differences in terms of SRs were obtained between both groups P = 0.286. CONCLUSIONS: The data analysis showed favorable results for treatment with 4 ZIs. The results showed no statistical differences in using 1 or another treatment, in terms of survival and failure rates. The reduction on treatment time and morbidity related to regenerative approaches may be its main advantage. In conclusion, the zygoma quad seems to be the treatment of choice for the rehabilitation of the severely atrophic maxilla.

Three-Dimensional Analysis of Long-Term Stability After Bilateral Sagittal Split Ramus Osteotomy Fixed With a Single Miniplate With 4 Monocortical Screws and 1 Bicortical Screw: A Retrospective 2-Center Study.

PURPOSE: This study evaluated the long-term stability of bilateral sagittal split ramus osteotomy fixed with a single miniplate with 4 monocortical screws and 1 bicortical screw (hybrid technique [HT]) using 3-dimensional (3D) analysis and an objective measuring tool, cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Sixty-four patients who underwent bimaxillary surgery with mandibular advancement fixed with the HT were selected from 2 different institutions and enrolled in this retrospective study. All patients underwent CBCT preoperatively, 1 month after surgery, and 12 months after surgery. To estimate the long-term stability of the HT, volumetric comparisons were performed using the following measurements: distance between the gonion and the B point in the sagittal plane; distance between the right and left gonion transversally; and the angle of the line connecting the mandibular notch and the gonion and the line connecting the gonion and the B point vertically. RESULTS: Statistical analysis showed no relevant relapse (<1 mm or <1°) when using the HT. However, a positive correlation between the amount of advancement and the amount of postoperative relapse was observed. CONCLUSION: The HT produces stable postoperative 3D results after 12 months.