Revolutionizing Maxillary Rehabilitation: Zygomatic Implants Addressing Severe Alveolar Atrophy.

This case report describes the care given to a 58-year-old male patient with severe upper jaw atrophy. The treatment strategy involved utilizing zygomatic implants in conjunction with endosteal implants to rehabilitate both the maxilla and mandible. Temporary prostheses were used during the healing phase, followed by the fabrication and placement of final prostheses. The utilization of zygomatic implants offers advantages such as immediate stabilization and function without the need for extensive bone grafting. This approach not only reduces treatment time and costs but also enhances patient outcomes. Furthermore, guided surgical techniques are increasingly employed to ensure precise implant placement, optimizing prosthetic support.

'Y' Modification of the cutaneous incision of the preseptal transconjunctival approach for the management of zygomatico-maxillary complex fractures: A prospective clinical study.

AIM: The purpose of this clinical study was to evaluate the efficacy of the preseptal transconjunctival approach with Y modification of the cutaneous extension for the management of zygomaticomaxillary complex (ZMC) fractures. METHODS: This prospective interventional study was conducted at our institute from 2012 to 2020. The study included patients aged 15-65 years with displaced ZMC fractures. Patients with uncontrolled systemic conditions, infected and/or comminuted fractures were excluded. The variables evaluated were age, gender, mechanism of injury, fracture side, clinical features, surgical exposure time, adequacy of exposure, complications, scar evaluation scores and cosmetic outcomes. The parameters for comparison were operated versus non operated side Eye Fissure Index (EFI) and surgical exposure time was compared with respect to the types of scars. RESULTS: A total of 49 patients were included in this study. The average exposure time was 18.87 ± 1.92 min. The exposure of fracture site was excellent in 73.5 % and satisfactory in 26.5 %. The mean EFI of operated side was 34.2 ± 5.04 mm while that of non-operated side was 34.22 ± 5 mm. On comparison of the same there was no significant difference. Invisible scars were noted in 71.4 % and barely visible scars in 22.4 %. The comparison of exposure time with type of scars showed a significant association (p = 0.02). The complications noted were chemosis, lower eyelid edema, conjunctival granuloma and entropion. Cosmetic outcomes were fairly satisfactory. CONCLUSION: The Y modification of the transconjunctival approach can provide excellent surgical exposure without the need for a second incision. Although this approach is technique sensitive and requires experience, the advantages outweigh the learning curve. Since this approach has been widely studied, a systematized review is recommended to further substantiate its reliability and advantages.

Evaluation of the Relationship Between Zygomatic Arch Fracture Reduction and Mandibular Movements.

Objective: The aim of this study was to evaluate the relationship between surgical zygomatic arch fracture reduction and mandibular movements in different fracture types. Materials and Methods: Fractures were classified according to the Yamamoto classification. The extent of zygomatic arch reduction after surgery was evaluated by measuring three reference points on both fractured and normal side both before and after surgery. The selected reference points were: the most anterior (A1), the most posterior (B1) and the midpoint (C1) relative to midsagittal plane on the fracture side and the same points on the normal side (a1, b1, c1). Mouth opening, movements to right and left were recorded in these patients. Results: The highest extent of zygomatic arch reduction was observed at the midpoint of the arch (p = 0.041). Surgery did not significantly alter other points of the zygomatic arch. The extent of reduction of the zygomatic arch was not significantly associated with mandibular movements. However, type of fracture correlated with lateral excursion to the right and left (p = 0.002 and p = 0.031, respectively). Conclusion: This study showed that the amount of post-surgical changes in zygomatic arch reduction was not significantly related to mandibular movements. In addition, the amount of lateral excursion two weeks after surgical correction of more severe types of zygomatic arch fractures was less compared with other fracture types. Patients with more severe fractures may need to be followed for a longer period of time in order to regain the normal mandibular movement range.

Comparative Evaluation of Sinus Complication and Survival Rates of Quad Zygoma versus Bizygoma in Combination with two Regular Implants in Atrophic Maxilla: A Systematic Review and Meta-Analysis.

Aim: To systematically review existing scientific literature to determine, compare and evaluate the sinus complication and survival rates of quad zygoma against two zygomatic implants with combination of two regular implants in atrophic maxilla in adults. Methods: Review was performed in accordance with preferred reporting items for systematic reviews and meta-analysis guidelines and registered in PROSPERO-CRD42023392721 Electronic databases like PubMed, Google scholar and EBSCO host were searched from 2000 to December 2022 for studies reporting treatment of Atrophic maxilla with either quad zygoma or two zygomatic implants in combination with two regular implants. Quality assessment was evaluated using Cochrane risk of bias-2 tool for randomized controlled trials (RCT). The risk of bias summary graph and risk of bias summary applicability concern was plotted using RevMan software version 5.3. The odds ratio (OR) and standardized mean difference (SMD) were used as summary statistic measure with random effect model and p value < 0.05 as statistically significant. Results: Eleven studies fulfilled the eligibility criteria and were included in qualitative synthesis, of which only nine studies were suitable for meta-analysis. The pooled estimate through the odds ratio 0.59 signifies that the quad zygomatic implants on an average has 0.59 (0.18-1.93) times or odds of developing sinus complications while the SMD signifies that better survival rate (SR) on an average is 0.35 (- 0.61 to 1.30) times more by two zygomatic implants with combination of two regular implants as compared to quad zygomatic implants (p > 0.05). Publication bias through the funnel plot showed asymmetric distribution with systematic heterogeneity. Conclusion: Two zygomatic implants in combination with two regular implants provides better survival rate and less sinus complications compared to quad zygoma in atrophic maxilla. Despite the high SR observed, there is a need to conduct more randomized controlled clinical trials to examine their efficacy in comparison with other techniques.

Biomechanical Evaluation of Zygomatic Implant Versus Pterygoid Implant in Atrophic Maxilla: An In vitro Finite Element Study.

Background and Purpose: Dental implants are considered to be one of several treatment options that can be used to replace missing teeth. The objective of the study is to examine and compare the biomechanics of zygomatic and pterygoid implants planned on the atrophic maxilla with three different bone types. Materials and Methods: An in vitro finite element study was conducted on a three-dimensional model of zygomatic and pterygoid implants. In a total of 24 implants, two bilateral zygomatic and pterygoid implants with two anterior dental implants were inserted in models. 150 N vertical occlusal and 300 N load on masseter and medial pterygoid were simulated on the modeled prosthesis. The data were processed with ANSYS software. The stress on and deformations of the bones and implants were observed and compared. Results: When comparing the D4, D3, and D2 bones in subgroup I with zygomatic implants, the D2 bone was subjected to less stress compared to D3 and D4. The smallest displacement (0.125784 mm) was seen in D4 followed by the largest displacement (0.74073 mm) in D2. Similarly, when comparing the D2, D3, and D4 bone in subgroup II with pterygoid implants, the D2 bone in the atrophic maxilla received the least amount of stress from the pterygoid implants compared to D3 and D4. Furthermore, the smallest displacement (0.030934 mm) was seen in D2, and the largest (0.046319 mm) in D4. Conclusion: Results suggest firstly, that the overall stress was better distributed in D2 bone and secondly, the pterygoid implant showed higher stress concentration than the zygomatic implant.

Assessing the frequency and variability of accessory zygomatic sutures in dry skulls: clinical insights and potential implications.

PURPOSE: This study aimed to determine the presence and incidence of accessory sutures and bipartite zygomatic bone types, and their effects on population affinity and clinical significance. METHODS: We examined 120 dry skulls and 50 zygomatic bones to evaluate the presence, frequency, and location of accessory zygomatic sutures as well as subtypes of bipartite zygomatic bones. Morphometric analysis included measuring the total width and length of the zygomatic bone with accessory sutures (ASs), the total length of the AS, and the shortest distance between the AS and various anatomical landmarks. RESULTS: Bipartite zygomatic bone was observed in 14 of 120 dry skulls (11.6%) and 1 of 50 zygomatic bones (2%), indicating an overall incidence of 16 occurrences (8.82%). The ASs were predominantly located posterolaterally in 11 cases (six males, five females), anteromedially in two cases (one male, one female), superiorly in one case (male), and superolaterally in one case (male). Significant differences were noted in the distribution of the ASs (p < 0.001). Notably, a vertical inferior bipartite zygomatic type, which has not been reported in the literature, was identified. Correlations were observed between the various anatomical landmarks. Among females, the length of AS was significantly different (p = 0.038). Significant differences were also noted in the shortest distance between the AS and the zygomaticofacial foramen (ZFF) based on the body side (p = 0.034). CONCLUSIONS: Our study suggests that the bipartite zygomatic bone is not a common occurrence, indicating its significance as a morphological variation present in certain individuals. The type VII bipartite zygomatic bone exhibited the highest incidence rate, suggesting potential ethnic-specific differences in the prevalence of certain subtypes. The consistent pattern of suture distribution, along with the asymmetry and variability in suture patterns, emphasizes its potential clinical relevance.

Prosthetic rehabilitation of patients with maxillary oncology defects using zygomatic implants.

PURPOSE: Prosthetics for patients after oncological resection of the upper jaw is a complex problem associated with the physiological and anatomical separation of the oral cavity and the nasal/paranasal region. This study reports the clinical results of the use of the zygomatic implants for prosthetic rehabilitation in patients with maxillectomy due to upper jaw tumors. MATERIALS AND METHODS: The study included 16 patients who underwent prosthetic rehabilitation using a zygomatic implant after maxillectomy period from 2021 to 2023. After the tumor was removed, immediate surgical obturators were placed. Main prosthetic rehabilitation was performed 6-12 months after tumor removal, but before that, a temporary obturator was made and used. Six-twelve months after tumor resection, 1-4 zygomatic implants were inserted into the zygomatic bone unilaterally or bilaterally. A total of 42 zygomatic implants were installed, 2 of which were unsuccessful and were removed in 1 patient. The implants were placed using the surgical guide, which was planned and prepared digitally. RESULTS: No postsurgical complications were seen, and the patients were discharged from the hospital after 7-10 days. The patients were able to return to a normal diet (hard food) after just 7 days following surgery, with no further complaints regarding function or pain, apart from the residual edema caused by the intervention. CONCLUSIONS: The use of prostheses fixed on zygomatic implants in patients with maxillary defects is an effective method of prosthodontic rehabilitation in complex clinical cases after maxillectomy.

Round and flat zygomatic implants: effectiveness after a 3­year follow­up non­interventional study.

PURPOSE: This non-interventional study investigates variations in the type and frequency of late complications linked to novel zygomatic implant designs, installed adhering to the Zygoma Anatomy-Guided Approach (ZAGA) concept, over an extended follow-up period of at least 3 years. METHODS: Consecutive patients presenting indications for treatment with ZIs were treated according to ZAGA recommendations. Implants were immediately loaded. The ORIS success criteria for prosthetic offset, stability, sinus changes and soft-tissue status were used to evaluate the outcome. RESULTS: Twenty patients were treated. Ten patients received two ZIs and regular implants; one received three ZIs plus regular implants, and nine received four ZIs. Fifty-nine ZIs were placed: thirty-six (61%) Straumann ZAGA-Flat implants and twenty-three (39%) Straumann ZAGA-Round implants. Four patients (20%) presented earlier sinus floor discontinuities. Fifteen patients (75%) had prior sinus opacities. Nineteen patients were followed for between 38 and 53 months (mean 46.5 months). One patient dropped out after 20 months. When comparing pre-surgical CBCT with post-surgical CBCT, 84.7% of the sites presented identical or less sinus opacity; nine locations (15%) showed decreased, and another nine increased (15%) post-surgical sinus opacity. Fifty-three ZIs (89.8%) maintained stable soft tissue. Six ZIs had recessions with no signs of infection. ZIs and prosthesis survival rate was 100%. CONCLUSIONS: The study highlights the effectiveness of ZAGA-based zygomatic implant rehabilitations using Round and Flat designs. Despite patient number constraints, minimal changes in the frequency of late complications from the 1-year follow-up were observed. 100% implant and prosthesis survival rate over a mean follow-up of 46.5 months is reported.

Orthodontic maxillary molar movement-induced zygomatic pillar remodeling and its consequences on occlusal characteristics and stress distribution.

OBJECTIVE: We aimed to evaluate changes in the zygomatic pillar during orthodontic treatment involving premolar extraction, analyze the effects of maxillary first molar movement on zygomatic pillar remodeling, and examine occlusal characteristics and stress distribution after remodeling. METHODS: Twenty-five patients who underwent premolar extraction were included in the study. The zygomatic pillar measurement range was defined, and cross-sectional areas, surface landmark coordinates, alveolar and cortical bone thicknesses, and density changes were assessed using Mimics software based on the cone-beam computed tomography scans taken before (T0) and after the treatment (T1). Multiple linear regression analysis was performed to determine the correlation between changes in the zygomatic pillar and maxillary first molar three-dimensional (3D) movement and rotation. Additionally, the correlation between pillar remodeling and occlusal characteristics was analyzed by Teetester. Pre- and post-reconstruction 3D finite element models were constructed and loaded with an average occlusal force of two periods. RESULTS: The morphological and structural remodeling of the zygomatic pillar after orthodontic treatment involving premolar extraction showed a decreased cross-sectional area of the lower segment of the zygomatic pillar. The zygomatic process point moved inward and backward, whereas the zygomatico-maxillary suture point moved backward. The thicknesses of the zygomatic pillar alveolar and cortical bones were thinner, and reduced alveolar bone density was observed. Simultaneously, the movement and angle change of the maxillary first molar could predict zygomatic pillar reconstruction to a certain extent. With decreasing the total occlusal force and the occlusal force of the first molar, occlusal force distribution was more uniform. With zygomatic pillar remodeling, occlusal stress distribution in the zygomatic alveolar ridge decreased, and occlusal stress was concentrated at the junction of the vertical and horizontal parts of the zygomatic bone and the posterior part of the zygomatic arch. CONCLUSIONS: Orthodontic treatment involving premolar extraction led to zygomatic pillar remodeling, making it more fragile than before and reducing the occlusal force of the maxillary first molar and the entire dentition with stress concentrated in weak areas. CLINICAL RELEVANCE: No other study has focused on the effects of orthodontics on pillar structures. The present study indicates that the mesial movement of the maxillary first molar weakened the zygomatic pillar and reduced occlusal function, thereby providing insights for inserting anchorage screws and facial esthetics.

All-on-4 Hybrid with Extra-Long Transnasal Implants: Descriptions of the Technique and Short-Term Outcomes in Three Cases.

Background/Objectives: There is a need for alternative approaches to full-arch rehabilitation of atrophic maxillae. The aim of this short case series was to describe the technique and assess the short term-outcomes of atrophic maxillae rehabilitation using transnasal implants in conjunction with zygomatic implants. Methods: Three female patients (average age: 62 years) presenting comorbidities and atrophic maxillae preventing the insertion of standard maxillary anchored implants received a full-arch fixed prosthesis supported by transnasal implants together with zygomatic implants, using the ad modum all-on-4 concept. Patients were followed during the functional osseointegration period. Primary outcome measures were prosthetic and implant survival based on function. Secondary outcome measures were complication parameters (biological and mechanical), plaque and bleeding levels, and probing pocket depths > 4 mm. Results: No implant failures were registered, and all prostheses remained in function. The only complication was a fracture of a provisional crown that was resolved. Plaque and bleeding scores were mild during the follow-up period. Conclusions: The present manuscript describes the use of extra-long transnasal implants in combination with zygomatic implants in immediate function for full-arch fixed prosthetic rehabilitation of atrophic maxillae, with the objective of promoting more research into this relatively recent technique. More studies are needed to validate the technique.

Open reduction and internal fixation of paediatric maxillozygomatic complex fractures: An 11-year multicentric retrospective study.

BACKGROUND/AIM: Paediatric maxillozygomatic complex (MZC) fractures are uncommon, and there is a scarcity of data regarding their surgical treatment. The aim of this study was to analyse choices and outcomes of open reduction and internal fixation (ORIF) for MZC fractures among 14 maxillofacial centers around the world. MATERIALS AND METHODS: This multicentric retrospective observational study included patients ≤16 years of age with quadripod MZC fractures treated with ORIF from January 2011 and December 2022. The following data were collected: age, gender, dentition stage (deciduous, mixed, and permanent), cause of injury, type of fracture, surgical approach, site of osteosynthesis (infraorbital rim, zygomaticomaxillary buttress, frontozygomatic, and zygomaticotemporal sutures), material (titanium or resorbable) and number of plates used, and outcome. The minimum follow-up was 6 months. Statistical analyses were performed with Fisher's exact test or chi-squared test, as appropriate. RESULTS: Sixty-four patients (mean age, 12.3 years) with quadripod MZC fractures were included. Seventy-two percent of patients received a single-point fixation. The zygomaticomaxillary buttress was the most common site for fixation, both in single-point and two-point fixation schemes, especially in combination with the frontozygomatic suture. Increasing age was associated with a higher rate of plate removal (p < .001). Postoperative complications included 5 (7.8%) cases of wound infections, 2 (3.1%) infraorbital paraesthesia, 1 (1.6%) ectropion. Residual facial asymmetry was found in 5 (7.8%) patients and was not associated with the type of fixation (p > .05). CONCLUSIONS: This study highlights the possibility of using ORIF, even with a single point of fixation, for the treatment of displaced quadripod MZC fractures in the paediatric population. The zygomaticomaxillary buttress was the preferred site of fixation and allowed for adequate stabilization with no external scars and a low risk of tooth damage. Future prospective studies with long-term follow-up are needed to establish definitive surgical protocols and clarify the surgical decision-making.

Dental Versus Zygomatic Implants in the Treatment of Maxillectomy: A Finite Element Analysis.

This study analyzed the stress distributions on zygomatic and dental implants placed in the zygomatic bone, supporting bones, and superstructures under occlusal loads after maxillary reconstruction with obturator prostheses. A total of 12 scenarios of 3-dimensional finite element models were constructed based on computerized tomography scans of a hemimaxillectomy patient. Two obturator prostheses were analyzed for each model. A total force of 600 N was applied from the palatal to buccal bones at an angle of 45°. The maximum and minimum principal stress values for bone and von Mises stress values for dental implants and prostheses were calculated. When zygomatic implants were applied to the defect area, the maximum principal stresses were similar in intensity to the other models; however, the minimum principal stress values were higher than in scenarios without zygomatic implants. In models that used zygomatic implants in the defect area, von Mises stress levels were significantly higher in zygomatic implants than in dental implants. In scenarios where the prosthesis was supported by tissue in the nondefect area, the maximum and minimum principal stress values on cortical bone were higher than in scenarios where implants were applied to defect and nondefect areas. In patients who lack an alveolar crest after maxillectomy, a custom bar-retained prosthesis placed on the dental implant should reduce stress on the zygomatic bone. The stress was higher on zygomatic implants without alveolar crest support than on dental implants.

Traumatic Hemifacial Avulsion and Degloving Injury With Left Zygomaticomaxillary Complex Fracture: A Case Report.

Managing gross maxillofacial injuries poses significant challenges due to potential complications such as airway obstruction, cervical spine injuries, and damage to cranial structures. The resultant deformities from these injuries can have enduring psychological effects, which, if left unaddressed, can be devastating. This report outlines an approach for a patient with a history of a bull gore injury wherein a 49-year-old male presented to the Department of Oral and Maxillofacial Surgery, reporting an alleged animal attack. The patient had experienced avulsion of the left eye and degloving injuries affecting the lower eyelids, nose, left cheek, and upper and lower lips, along with skin over the chin, coupled with a left zygomaticomaxillary complex fracture. Subsequently, a comprehensive single-stage primary reconstruction and repair procedure was performed. Immediate single-stage reconstruction has shown success in achieving excellent functional and aesthetic outcomes. Preserving original tissue during debridement is crucial in preventing infection and minimizing flap loss.

A Retrospective Multicentric Study of 52 Nasal and Trans-nasal Implants in 31 Severe Atrophic Patients to Reduce Anterior Cantilever Bending in Full Arch Implant-supported Fixed Rehabilitation.

PURPOSE: Severe anterior maxillary atrophy offers few implant-supported rehabilitation solutions to Quad Zygoma characterized by a wide anterior cantilever. One of the possible alternatives to consider before the quad zygoma is the extra-long nasal/trans-nasal implant placement. This retrospective multicentric study shows the predictability of nasal/transnasal implant placement in patients affected by severe anterior maxilla atrophy, with residual anatomical features that indicate this surgery. This specific remote anchorage can often be safely involved in immediate loading with other remote anchorages, such as zygoma and pterygoid implants. In this rehabilitation, it's mandatory to reduce the instability of the frameworks and mechanical stress that could unfavorably affect the implant's prognosis due to the overloading derived from anterior bending. MATERIALS AND METHODS: In this retrospective multicentric study, 52 nasal or trans-nasal implants were inserted in 31 atrophic anterior maxillas (Cawood and Howell's class V-VI). All implants were successful after the healing period; even if 27 nasal implants reached an insertional torque equal to or greater than 50 n/cm2, the threshold value estimated to be able to support an immediate load. RESULT: All 52 implants were successful, so the proportion of success was 100%, with a 97.5% one-sided confidence interval of 88.8-100%. The success rate is achieved only if at least two of the following criteria are met: 1) a greater torque than 50 Ncm as a minimum sufficient condition to plan immediate loading; 2) after a healing period of 16 weeks, the secondary stability is clinically and radiographically evaluated to exclude possible coronal bone resorption: this condition allows the successive prosthetic finalization; 3) the possibility of carrying out a full arch rehabilitation with minimal anterior spread. Insertion torque was <50 Newton centimeters (Ncm) in 14 patients (45%) and 50 Ncm in 17 (55%). Mechanical load was delayed in the former and immediate in the latter. The proportion of torque <50 Ncm was higher in men than in women (69% versus 28%, p=0.033). Immediate torque was not significantly affected by age. CONCLUSION: Although the sample is not extremely numerically significant, it conveys a clear and significant clinical, surgical indication as never before in the literature; we can state that nasal/trans nasal implants have been very useful in reducing the anterior cantilever and overcoming the anatomical limitations affecting conventional Quad Zygoma.

Effectiveness of zygomatic-implant fixed rehabilitation for the atrophic edentulous maxilla: protocol for a systematic review and network meta-analysis.

BACKGROUND: Atrophic edentulous maxilla is a debilitating condition caused by the progressive and irreversible bone resorption following loss of teeth, that results in bone of inadequate volume and density. This makes conventional implant therapy extremely challenging without complex reconstructive procedures. Several techniques such as sinus augmentation, short implants, and tilted implants have been used for the rehabilitation of the atrophic maxilla. In recent years, zygomatic implants have emerged as a graftless rehabilitation technique. However, few studies compare zygomatic-implant fixed rehabilitation with other fixed rehabilitation techniques. The existing body of evidence on zygomatic implants is largely based on clinical and disease-oriented outcomes. METHODS: A network meta-analysis (NMA) will be conducted in order to compare the effectiveness of zygomatic-implant fixed rehabilitation with the other rehabilitation techniques. Experimental and observational studies comparing different implant-assisted fixed rehabilitation in adults with atrophic maxilla will be included. The primary and secondary outcomes will be patient's satisfaction and quality of life respectively. Additional outcomes include the implant's survival/success, and biological and prosthetic complications. An electronic search will be performed through various databases for articles in English and French, without time limits. Risk of bias will be assessed using the Revised Cochrane Risk-of-Bias tool for randomized controlled trials, and ROBINS-I for non-randomized and observational studies. Two independent reviewers will screen the titles and abstracts and extract data. Any discrepancy between reviewers will be discussed and resolved through consensus or with the help of a third reviewer. Pairwise meta-analyses will be performed using a random effects model. I2, τ2, transitivity, subgroup/meta-regression analyses will assess and explain heterogeneity and distribution of effect modifiers. A network plot will be created to connect the different interventions directly and indirectly. Interventions will be ranked using the surface under cumulative ranking curve. Confidence in the results of the NMA will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). DISCUSSION: This study will be the first to assess the effectiveness of zygomatic-implant fixed rehabilitation for the atrophic maxilla using NMA. The evidence obtained will aid clinical decision-making and will advance the knowledge of the rehabilitation techniques for the atrophic maxilla. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42023353303.

Closed Reduction of an Isolated Zygomatic Arch Fracture Under Local Anesthesia: A Case Report.

The zygomatic bone is one of the most prominent bones in the facial region. It forms the most anterolateral projection on each side of the middle face and is articulated with the maxilla, frontal, and temporal bones. Isolated zygomatic arch fractures can occur when a direct force is applied to the zygoma. A variety of intraoral and extraoral techniques have been used as closed reduction techniques for isolated fractures of the zygomatic arch. In this case report, we aim to present our approach for the treatment of a 40-year-old patient with an isolated right zygomatic arch fracture. We used the Keen technique for the closed reduction of the fracture under local anesthesia due to its practicality and effectiveness.

The 'Manchester' method of minimal access fixation of the zygomatic arch in zygomatic complex fractures: a case series.

We have introduced a minimally invasive approach for the fixation of the zygomatic arch during the surgical management of zygomatic complex fractures. Access for this technique is provided by a preauricular approach and eyelid incisions with the addition of transcutaneous stab incisions overlying the arch. These stab incisions allow transcutaneous drilling and screw placement through a size CH 20 (5.0 mm) paediatric nasopharyngeal airway (NPA). We present a case series of seven patients. In all patients the arch component was successfully reduced and fixed, and no intraoperative or postoperative complications were observed. The use of an NPA is novel. It functions as a flexible self-irrigating sleeve and protects the skin from mechanical and thermal damage. The technique uses readily available equipment, is easy to learn, and simplifies surgery to the zygomatic arch.

Evaluation of Different Patterns of Zygomaticoorbital Complex Fractures.

Study Design: Very few studies exist regarding the fracture pattern variability of the zygomaticoorbital (ZMO) complex. The retrospective evaluation of a large series of surgically treated unilateral ZMO fractures would in certain circumstances help intraoperative predictability and define sensitive indicators for open reduction and internal fixation. Objective: The aim of this study was to investigate the different fracture patterns after ZMO complex injury regarding the 5 anatomic sutures of the zygoma as well as the concomitance of the paranasal buttress and maxillary sinus wall fracture. Methods: The medical records of all patients with unilateral ZMO fractures who underwent surgical intervention in a single trauma center department between April 2015 and June 2020 were retrospectively reviewed. Demographic and anamnesis data, radiologic findings, and surgical reports were evaluated. According to the preoperative radiologic evaluation, ZMO fractures were classified as unisutural, bisutural, trisutural, tetrasutural, and complete based on the number of zygomatic sutures. The prevalence of various fracture patterns was analyzed. The impact of patient's age and trauma etiology on the fracture pattern was evaluated using descriptive statistical analysis. Results: The study included 492 patients with unilateral ZMO fractures, with a mean age of 49.93 years (SD = 20.66) and a male:female ratio of 2.23:1. The most affected age group was 19-44 years (41.67%) and tripping falls were the most common etiology (27.24%). Trisutural (57.32%) and unisutural fractures (23.17%) were the most common, followed by tetrasutural (8.94%), bisutural (8.54%), and complete fractures (2.03%). A trisutural fracture involving the zygomaticomaxillary suture, the infraorbital rim, and the zygomaticosphenoidal suture was the most common fracture pattern (52.03%). Most fractures were observed in the zygomaticosphenoidal suture (86.99%), followed by the infraorbital rim (74.59%) and the zygomaticomaxillary suture (68.29%). Fractures of the maxillary sinus wall and the paranasal buttress co-existed in 9.55% and 31.30% of all cases, respectively. No correlation was detected between age and fracture pattern (P = .4111). Tripping falls and bicycle accidents significantly influenced the fracture pattern (P < .0001). Conclusions: According to the results, knowledge of the fracture pattern variability of the ZMO complex could in certain circumstances designate CT or CBCT as mandatory before operating on ZMO fractures. Consequently, unnecessary incisions could be avoided. The high concomitance of paranasal buttress fracture also suggests its intraoperative surgical exploration. Further studies should correlate the clinical findings with indication for surgery and postoperative outcome for the different fracture patterns described.

The precision of drill calibration for dynamic navigation.

OBJECTIVES: To quantify the reproducibility of the drill calibration process in dynamic navigation guided placement of dental implants and to identify the human factors that could affect the precision of this process in order to improve the overall implant placement accuracy. METHODS: A set of six drills and four implants were calibrated by three operators following the standard calibration process of NaviDent® (ClaroNav Inc.). The reproducibility of the position of each tip of a drill or implant was calculated in relation to the pre-planned implants' entry and apex positions. Intra- and inter-operator reliabilities were reported. The effects of the drill length and shape on the reproducibility of the calibration process were also investigated. The outcome measures for reproducibility were expressed in terms of variability range, average and maximum deviations from the mean distance. RESULTS: A satisfactory inter-rater reproducibility was noted. The precision of the calibration of the tip position in terms of variability range was between 0.3 and 3.7 mm. We noted a tendency towards a higher precision of the calibration process with longer drills. More calibration errors were observed when calibrating long zygomatic implants with non-locking adapters than with pointed drills. Flexible long-pointed drills had low calibration precision that was comparable to the non-flexible short-pointed drills. CONCLUSION: The clinicians should be aware of the calibration error associated with the dynamic navigation placement of dental and zygomatic implants. This should be taken in consideration especially for long implants, short drills, and long drills that have some degree of flexibility. CLINICAL SIGNIFICANCE: Dynamic navigation procedures are associated with an inherent drill calibration error. The manual stability during the calibration process is crucial in minimising this error. In addition, the clinician must never ignore the prescribed accuracy checking procedures after each calibration process.

Clinical Anatomy of the Ligaments of the Face and Their Fundamental Distinguishing Features.

Our study aimed to clarify the anatomical features of the zygomatic, upper masseteric, lower masseteric and mandibular ligaments and their possible contribution to age-related gravitational ptosis. The study was carried out by the method of layered dissection of fresh cadavers. In several observations, the zygomatic ligament is represented by the fibers originating from the zygomaticus major muscle fibers. It is a true ligament with the fibers inserted directly into the skin. The upper and lower masseteric ligaments originate from the parotideomasseteric fascia and weave into the thickness of the SMAS. The mandibular ligament consists of two connective tissue laminae originating from the parotideomasseteric fascia at the lower edge of the mandible and from the inner surface of this fascia, along the anterior edge of the masseter muscle, skirting the facial vein sheath and the facial artery, traveling toward the platysma and the depressor anguli oris muscle, and merging with their fibers. The zygomatic ligament should be considered an osteo-musculocutaneous ligament, emphasizing the role of the associated zygomaticus major muscle in the mechanism of aging. The upper and lower masseteric and mandibular ligaments are false fascio-SMAS ligaments rather than osteo-cutaneous ones, playing the barrier role and fixing the superficial fascia and the platysma muscle.