Guided placement of zygomatic implants in head and neck cancer patients: implant survival and patient outcomes at 1-3 years of follow-up

Zygomatic implants (ZI) are a valuable option for supporting an obturator prosthesis after maxillary resection. This study was performed to assess the clinical outcomes of a digitally validated guided technique for ZI placement, followed by immediate prosthetic obturation. The primary objective was to evaluate implant survival, while the secondary objective was to assess patient-reported quality of life post-rehabilitation. Twelve patients treated for head and neck cancer received a total of 36 ZI after ablative surgery. The mean duration of ZI follow-up was 30.1 months. The survival rate of ZI placed in non-irradiated patients was 100%, while it was 85% in irradiated patients. Patient-reported outcomes were evaluated using the Liverpool Oral Rehabilitation Questionnaire (LORQv3) and the University of Washington Quality of Life Questionnaire (UW-QOL v4). Most patients reported satisfactory outcomes in the oral function domain of the LORQv3 (mean score 17.7 ± 4.5; possible range 12-48, with lower scores indicating better outcomes). Regarding the UW-QOL v4, the swallowing and chewing domains had the highest scores (mean 97.5 ± 8.7 and 95.8 ± 14.4, respectively; maximum possible score of 100). In conclusion, this treatment approach improves function and quality of life after maxillary ablative surgery. However, irradiated patients showed a noticeable trend of higher implant failure, and this was influenced by tumour position and size impacting the radiation dose to the zygomatic bone.

Role of finite element analysis for selection of single point fixation in zygomaticomaxillary complex fracture

BACKGROUND

One-point fixation was superior to the two and three-points fixation in minimally displaced zygomaticomaxillary complex (ZMC) fracture regarding the cost, invasiveness, scaring, number of wounds, and operation time. Accordingly, this study aimed to predict which one-point fixation is the most stable in managing minimally displaced ZMC fracture.

MATERIAL & METHODS

This study simulated the different one-point fixation approaches on three ZMC models after fracture reduction and application of all forces exerted on the fractured area. The findings were represented as stress impact on the ZMC fracture and plating system as well as the inter-fragments micro-motion.

RESULTS

The von misses stresses of plates for the zygomaticofrontal, infra-orbital rim, and zygomaticomaxillary buttress model were (66.508, 1.285, and1.16 MPa) respectively. While the screws' von misses for the infraorbital rim, zygomaticofrontal, and zygomaticomaxillary buttress models were (13.8, 4.05, and 1.60 MPa) respectively. Whereas, the maximum principles stress at zygomaticofrontal, zygomaticomaxillary buttress, and infraorbital rim models were (37.03, 37.01, and 34.46 MPa) respectively. In addition, the inter-fragment micro-motion for zygomaticomaxillary buttress, infraorbital rim, and zygomaticofrontal models were (0.26, 0.25, and 0.15 mm) respectively.

CONCLUSION

One-point fixation at zygomaticomaxillary buttress is the preferred point because it is exposed to low stresses, and the inter-fragment micro-motion is within the approved limit with the elements in the same direction of fixation which indicates the rigid fixation. In addition, it is less palpable and scarless.

TRIAL REGISTRATION

clinical trial.gov (NCT05819372) at 19/04/2023.

Intraosseous Hemangioma of Zygoma: A Case Report with Review of Literature

Intraosseous hemangiomas are uncommon and account to less than 1% of all osseous tumors. Vertebral body and skull are the most common sites involved. However involvement of facial bones is rare with zygoma being even rarer site. Due to its rarity it creates diagnostic dilemma clinically and radiologically. Its vascular nature carries the risk of intraoperative bleeding hence an accurate preoperative diagnosis with arterial embolization helps to avoid the dire consequences. Fine needle aspiration cytology along with radiological correlation is extremely helpful in such cases. We report such rare case in forty eight years female patient with brief review of literature.

Single-stage computer-assisted approach for tumour resection and functional restoration of Brown class III maxillary defects-titanium mesh and zygomatic implants combined with vascularized anterolateral thigh flap

The functional restoration of Brown class III maxillary defects is a challenging endeavour in oral and maxillofacial surgery. Conventional reconstruction techniques with osseous free flaps have certain limitations, such as the need for multiple operations and greater patient morbidity. This study introduces a single-stage computer-assisted approach for tumour resection and functional restoration of these defects using titanium mesh, zygomatic implants, and a vascularized anterolateral thigh flap (ALTF). Virtual surgical planning was used to simulate tumour resection, titanium mesh placement, and zygomatic implant insertion. Surgery was performed under the guidance of mixed reality and surgical navigation. The tumour was resected by total hemimaxillectomy, and the reconstruction was performed using a pre-bent patient-specific titanium mesh for the orbital floor and two zygomatic implants placed and exposed through tunnels in an ALTF. The ALTF survived without any perioperative complications. A fixed prosthesis with built-in titanium frame was delivered 4 months postoperatively. At the 1-year follow-up, there was no tumour recurrence, the implants were osseointegrated, and aesthetics and masticatory function were satisfactory. An occlusal force of 155 N was attained on the reconstructed side, compared to 127 N on the non-surgical side.

Long-term treatment outcomes with zygomatic implants: a systematic review and meta-analysis

PURPOSE

The purpose of this study was to perform a systematic review with meta-analysis on the long-term survival rates of zygomatic implants (ZI). ZI success, prostheses survival and success, sinus pathology and patient reported outcomes were also investigated.

METHODS

Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines were followed. Embase and OvidMedline databases were searched alongside the grey literature. The systematic review was recorded in PROSPERO (CRD42022358024). Studies reporting titanium/titanium alloy ZI survival data, ZI-supported prosthesis data, ZIs directly compared to any other implant therapy including grafted sites, a minimum follow-up time of 3 years and a minimum number of 10 patients were included. All study designs were considered if they met the inclusion criteria. Studies not involving ZIs, ZIs not made from titanium/titanium alloy, a follow-up time of < 3 years or < 10 patients, animal studies and in vitro studies were excluded. Long-term follow-up has not been defined in the literature. A minimum of 3 years follow-up was considered acceptable to capture survival after initial healing, alongside in-function prosthesis data via delayed or immediate load protocols. ZI success, was predominantly defined as ZI survival without biological or neurological complications. Meta-analyses were performed for ZI survival, ZI failure incidence, ZI success, loading protocol, prosthesis survival, and prevalence of sinusitis using random effects models. Descriptive analysis was used for ZI success, prosthesis success and patient reported outcome measures.

RESULTS

Five hundred and seventy-four titles were identified, of which 18 met the inclusion criteria. Eligible studies included 1349 ZIs in 623 patients. Mean follow-up period was 75.4 months (range 36-141.6). The mean survival of ZIs was 96.2% [95% CI: 93.8; 97.7] at 6 years. Mean survival for delayed loading was 95% [95% CI: 91.7; 97.1] and 98.1% [95% CI: 96.2; 99.0] for immediate loading (p = 0.03). Annual incidence rate of ZI failure was 0.7% [95% CI 0.4; 1.0]. Mean ZI success was 95.7% [95% CI 87.8; 98.6]. Mean prosthesis survival was 94% [95% CI 88.6; 96.9]. Sinusitis prevalence was 14.2% [95% CI 8.8; 22.0] at 5 years. Patients' reported increased satisfaction with ZIs.

CONCLUSIONS

ZIs have long-term survival comparable to conventional implants. Immediate loading showed a statistically significant increase in survival over delayed loading. Prosthesis survival was similar to that of prostheses supported by conventional implants, with similar complications. Sinusitis was the most frequently encountered biological complication. Patients reported improved outcome measures with ZI use.

Indications for zygomatic implants: a systematic review

PURPOSE

The purpose of this systematic review was to assess the evidence regarding the indications for placement of zygomatic implants to rehabilitate edentulous maxillae.

MATERIAL AND METHODS

A focused question using the PIO format was developed, questioning "in patients in need of an implant-supported rehabilitation of the edentulous maxillae, what are the indications for the use of zygomatic implants''. The primary information analyzed and collected was a clear description of the indication for the use of zygomatic implants.

RESULTS

A total of 1266 records were identified through database searching. The full-text review was conducted for 117 papers, and 10 were selected to be included in this review. Zygomatic implant indications were extreme bone atrophy or deficiency secondary to different factors. The quad zygoma concept (two zygomatic implants bilaterally placed and splinted) was applied to 107 patients, the classic zygoma concept (one zygomatic implant bilaterally placed and splinted to standard anterior implants) was used in 88 patients, and the unilateral concept (one zygomatic implant on one side, splinted with one or more conventional implants) was employed in 14 patients.

CONCLUSIONS

The main indication for the use of zygomatic implants was considered extreme maxillary bone atrophy, resulting from many factors. The clear definition of what was considered "extreme bone atrophy" is not uniquely defined in each paper. Further studies are needed to develop clear indications for zygomatic implants.

Intraosseous venous malformation of the zygoma: Case report and pooled analysis

The objective of this study is to provide a comprehensive summary of the clinical and radiological features of zygomatic intraosseous venous malformations (IVM), as well as its treatment strategies. The aim is to establish preoperative diagnostic bases that will aid in the identification of zygomatic IVM and facilitate the implementation of effective treatment. Four cases of pathologically diagnosed zygomatic IVM with typical clinical and radiological features were reported. They exhibited comparable clinical and radiological features, and the En bloc excision and reconstruction yielded satisfactory outcome. Pooled data analysis was performed with additional 74 cases collected from 63 previous studies. The results revealed a higher incidence of zygomatic IVMs in middle-aged females, with swelling, pain and ocular dysfunction being the typical clinical manifestations. The characteristic radiological features of these lesions were well-defined, round bony structures with specific internal trabecular patterns. A diagnostic flow-chart assisting the differential diagnosis of IVM was established. En bloc excision was deemed the most advantageous treatment option, as it presented minimal risk of haemorrhaging and no instances of recurrence. The decision to pursue reconstruction was contingent upon the extent of the defect. Alloplastic material has emerged as the most frequently employed reconstruction material in recent reports. The summarized characteristics of zygomatic IVM and the proposed diagnostic and treatment strategies, derived from the pooled analysis of reported cases, may help to improve diagnosis and management in further clinical practice.

A deep learning-based automatic segmentation of zygomatic bones from cone-beam computed tomography images: A proof of concept

OBJECTIVES

To investigate the efficiency and accuracy of a deep learning-based automatic segmentation method for zygomatic bones from cone-beam computed tomography (CBCT) images.

METHODS

One hundred thirty CBCT scans were included and randomly divided into three subsets (training, validation, and test) in a 6:2:2 ratio. A deep learning-based model was developed, and it included a classification network and a segmentation network, where an edge supervision module was added to increase the attention of the edges of zygomatic bones. Attention maps were generated by the Grad-CAM and Guided Grad-CAM algorithms to improve the interpretability of the model. The performance of the model was then compared with that of four dentists on 10 CBCT scans from the test dataset. A p value <.05 was considered statistically significant.

RESULTS

The accuracy of the classification network was 99.64%. The Dice coefficient (Dice) of the deep learning-based model for the test dataset was 92.34 ± 2.04%, the average surface distance (ASD) was 0.1 ± 0.15 mm, and the 95% Hausdorff distance (HD) was 0.98 ± 0.42 mm. The model required 17.03 seconds on average to segment zygomatic bones, whereas this task took 49.3 minutes for dentists to complete. The Dice score of the model for the 10 CBCT scans was 93.2 ± 1.3%, while that of the dentists was 90.37 ± 3.32%.

CONCLUSIONS

The proposed deep learning-based model could segment zygomatic bones with high accuracy and efficiency compared with those of dentists.

CLINICAL SIGNIFICANCE

The proposed automatic segmentation model for zygomatic bone could generate an accurate 3D model for the preoperative digital planning of zygoma reconstruction, orbital surgery, zygomatic implant surgery, and orthodontics.

C-Arm a Useful Tool for Surgeons in Reduction of Zygomatic Complex Fracture: A Comparative Study: Article Type-Original Research

Introduction

Reduction of zygomaticomaxillary (ZMC) fracture is often difficult to evaluate intraoperatively because of it peculiar anatomy and limited accessibility. The purpose of this study is to evaluate the efficacy of use of C-arm as a tool for intraoperative monitoring of ZMC fracture reduction.

Materials and Methods

Group I (C-Arm) and Group II (control group) comprised of patients with isolated unilateral displaced Zygomatic complex (ZMC) fractures and having orbital volume change. The efficacy of use of C-arm intra-operatively was evaluated to analyse the reduction of fracture.

Results

It was observed that mean change in ocular volume was around 1.07cm2 for Group I and 1.51cm2 in Group II. Thus post-operative eye volume was near to normal in Group I than Group II. The change in ocular volume post-operatively was observed to be statistically significant (p-value < 0.05) in both the groups. Post HOC Tukey statistical analysis determined the intergroup relation in change in eye volume between normal, pre- and post-operative and was found to be statistically significant (p-value < 0.05). The intergroup comparison between Group I and Group II was done using ANOVA statistical analysis and was found to be statistically significant (p-value < 0.05).

Discussion

Our study revealed that C-arm is definitively an effective tool in the oral and maxillofacial surgery armamentarium, giving better results with minimal surgical exposure and by eliminating operator related error.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03221-y.

Medication-related osteonecrosis of the upper jaw involving the zygomatic bone: A case report

INTRODUCTION AND IMPORTANCE

Osteonecrosis of the jaw resulting from treatment with antiresorptive agents, such as bisphosphonates and denosumab, is widely recognized as medication-related osteonecrosis of the jaw (MRONJ). However, to the best of our knowledge, there are no reports of medication-related osteonecrosis of the upper jaw extending to the zygomatic bone.

CASE PRESENTATION

An 81-year-old woman treated with denosumab for multiple lung cancer bone metastases presented to the authors' hospital with a swelling in the upper jaw. Computed tomography showed osteolysis, periosteal reaction of the maxillary bone, maxillary sinusitis, and osteosclerosis of the zygomatic bone. The patient underwent conservative treatment; however, osteosclerosis of the zygomatic bone progressed to osteolysis.

CLINICAL DISCUSSION

If the maxillary MRONJ extends to the surrounding bony structures, such as the orbit and skull base, serious complications may occur.

CONCLUSION

It is important to detect early signs of maxillary MRONJ, before it involves the surrounding bones.

Dynamic navigation for zygomatic implant placement: A randomized clinical study comparing the flapless versus the conventional approach

OBJECTIVES

The assessment of the accuracy of flapless placement of zygomatic implants in edentulous maxilla using dynamic navigation.

METHODS

A randomized controlled trial was carried out on 20 patients. Patients were randomized into two groups, the flapless (Group 1; n=10) and the conventional (Group 2; n=10). In each case two zygomatic implants were inserted under local anaesthesia, one on the right and one on the left side guided by a dynamic navigation system. The surgical procedure was identical in the two groups except for the reflection of the mucoperiosteal flap which was eliminated in the flapless cases. Postoperative CBCT scans were used to assess the accuracy of the placement of zygomatic implants.

RESULTS

Osseointegration was achieved for all the implants, except one case in the flapless group. Statistically significant differences in the accuracy of the position of the zygomatic implants was found between the flapless and the conventional groups, measured at the apex and the entry points of the implants (p < 0.01). The average apical and coronal deviations were 5 mm and 3 mm, respectively; the angular deviation was 6°, and 2 mm vertical apical disparity was detected between the planned and the achieved surgical position. Perforation of the Schneiderian membrane was noted in three cases, one in flapless group and two in the conventional group.

CONCLUSIONS

Flapless placement of zygomatic implants guided by dynamic navigation offered satisfactory safety and accuracy.

CLINICAL SIGNIFICANCE

This is the first clinical trial to prove the feasibility and accuracy of flapless placement of zygomatic implant with minimal morbidity. The study highlights the innovative reflection of the Schneiderian membrane under guided surgical navigation. The procedure can be performed under local anaesthesia, which offers clinical advantages. Adequate training on the use of dynamic navigation is mandatory before its use in clinical cases.

Discrepancy of the location of depression on the soft tissue and the bone in isolated zygomatic arch fracture

BACKGROUND

When performing reduction of zygomatic arch fractures, locating the inward portion of the fracture can be difficult. Therefore, this study investigated the discrepancy between the locations of the depression on the soft tissue and bone and sought to identify how to determine the inward portion of the fracture on the patient's face.

METHODS

We conducted a retrospective review of chart with isolated zygomatic arch fractures of type V in the Nam and Jung classification from March 2013 to February 2022. For consistent measurements, a reference point (RP), at the intersection between a vertical line passing through the end point of the root of the ear helix in the patient's side-view photograph and a transverse line passing through the longest horizontal axis of the external meatus opening, was established. We then measured the distance between the RP and the soft tissue depression in a portrait and the bone depression on a computed tomography (CT) scan. The discrepancy between these distances was quantified.

RESULTS

Among the patients with isolated zygomatic arch fractures, only those with a fully visible ear on a side-view photograph were included. Twenty-four patients met the inclusion criteria. There were four types of discrepancies in the location of the soft tissue depression compared to the bone depression: type I, forward and upward discrepancy (7.45 and 3.28 mm), type II, backward and upward (4.29 and 4.21 mm), type III, forward and downward (10.06 and 5.15 mm), and type IV, backward and downward (2.61 and 3.27 mm).

CONCLUSION

This study showed that discrepancy between the locations of the depressions on the soft tissue and bone exists in various directions. Therefore, applying the transverse and vertical distances measured from a bone image of the CT scan onto the patient's face at the indicated RP will be helpful for predicting the reduction location.

Evaluation of sub-brow approach to the frontozygomatic suture for Open Reduction and Internal Fixation (ORIF) of Zygomatico maxillary complex (ZMC) fractures: A prospective cohort study

Introduction

Contemporary incisions used to access the frontozygomatic (FZ) sutures are the lateral brow and upper blepharoplasty incisions which are associated with specific limitations and complications. The authors describe the use of sub-brow incision as an alternate approach for exposure of the FZ region.

Methods

This is a prospective cohort study involving patients requiring surgical management of zygomatico maxillary complex (ZMC) fractures with fixation at FZ suture alone or along with fixation at infra-orbital rim and/or zygomaticomaxillary buttress. A sub-brow incision was used to expose the fracture and fixation was done with a 4-hole miniplate. The parameters evaluated were specific to the FZ region (sub-brow incision), namely surgical access, bleeding, fracture exposure time, post-operative scar, and pain. Each patient was reviewed on 1st, 5th, 7th, 10th, 30th, and 90th day.

Results

The study sample included eight male patients. The mean age was 30 years. The sub-brow incision demonstrated favorable postoperative outcomes; adequate exposure was achieved in all 8 patients. The scar formation was found to be higher on the 7th day and the least scar formation was seen by the third month. The mean pain score was found to be high on first post-operative day and the least pain was seen by the 10th day. The mean score of surgical field bleeding was found to be 1.75 which signified mild bleeding according to Fromme's scale. The mean time taken for adequate exposure of the fracture was 6.62 min. All the assessment parameters were statistically significant (P value <0.01).

Conclusion

Sub-brow incision is an effective approach for ORIF of zygomatic fractures at FZ suture. The technique is quick, simple, and associated with minimal complications.

Osteoma of the zygomatic bone from 16th century Sardinia (Italy) in the framework of a paleoepidemiological study

OBJECTIVE

The aim of this paper is to evaluate a case of osteoma of the zygomatic bone in a post-medieval individual in the context of a paleoepidemiological approach.

MATERIALS

Forty-five skulls from the plague cemetery of Alghero (Sardinia, Italy), dating back to the end of the 16th century, were evaluated for the presence of osteomata on the outer surface of the cranial vault and facial bones.

METHODS

Macroscopic examination was performed using standard anthropological methods. The bone presenting the lesion was submitted to radiological examination through cone beam; a 3D reconstruction was obtained with a surface 3D scanner.

RESULTS

Only one case of osteoma was observed in an adolescent aged 13-15 years, located on the right zygomatic bone. The lesion consisted of a rounded mass of 0.5 cm in diameter composed of compact bone, as also the radiographic study demonstrates. The prevalence of osteoma on the outer surface of the cranial vault and facial bones in the population of Alghero was 2.2 %.

CONCLUSIONS

This case offers the opportunity to enrich the knowledge about the presence of benign tumors among past populations and to evaluate this lesion in dry bone.

SIGNIFICANCE

This study provides paleoepidemiological data on the scarce area of benign tumors in paleo-oncology and presents the first documented osteoma of the zygomatic bone in paleopathology.

LIMITATION

Histological study was not performed for conservative issues.

SUGGESTIONS FOR FUTURE RESEARCH

Increasing the attention to benign tumors is essential to deepen our knowledge about paleoepidemiology of neoplastic lesions.

Minimally Invasive Single-Point Stabilization of Zygomaticomaxillary Complex Fractures

Objective

This study aimed to present a minimally invasive surgical management of zygomaticomaxillary complex (ZMC) fractures with reduction and single-point stabilization over the frontozygomatic buttress.

Methods

This prospective cohort study was conducted on cases of ZMC fractures. The inclusion criteria were displaced tetrapod zygomatic factures, asymmetry of the facial bones, and unilateral lesion. The exclusion criteria were extensive skin or soft tissue loss, comminuted inferior orbital rim, limited ocular mobility, and enophthalmos. Surgical management included reduction and single-point stabilization over the zygomaticofrontal suture with miniplates and screws. The outcome measure was correction of the clinical deformity with less scarring and low postoperative morbidity. The late outcome was maintenance of a stable fixed reduced zygoma over the follow-up period.

Results

Forty-five patients were included in the study with a mean age of 30 ± 5.56 years. The study included 40 men and 5 women. Motor vehicle accident was the most common cause of fracture (62.2%). They were managed via lateral eyebrow approach with single-point stabilization over the frontozygomatic suture after reduction. Preoperative and postoperative and radiologic images were available. All cases had optimum correction of the clinical deformity. Postoperative stability was excellent in the follow-up period, which had a mean of 18.5 ± 7.81 months.

Conclusion

There is an increased interest in minimally invasive procedures, and concerns about scarring have increased. Therefore, single-point stabilization over the frontozygomatic suture provides good support to the reduced ZMC with low morbidity.

Sensory change and recovery of infraorbital area after zygomaticomaxillary and orbital floor fractures

BACKGROUND

To compare the sensory change and recovery of infraorbital area associated with zygomaticomaxillary and orbital floor fractures and their recoveries and investigate the factors that affect them.

METHODS

We retrospectively reviewed 652 patients diagnosed with zygomaticomaxillary (n= 430) or orbital floor (n= 222) fractures in a single center between January 2016 and January 2021. Patient data, including age, sex, medical history, injury mechanism, Knight and North classification (in zygomaticomaxillary fracture cases), injury indication for surgery (in orbital floor cases), combined injury, sensory change, and recovery period, were reviewed. The chi-square test was used for statistical analysis.

RESULTS

Orbital floor fractures occurred more frequently in younger patients than zygomaticomaxillary fractures (p< 0.001). High-energy injuries were more likely to be associated with zygomaticomaxillary fractures (p< 0.001), whereas low-energy injuries were more likely to be associated with orbital floor fractures (p< 0.001). The sensory changes associated with orbital floor and zygomaticomaxillary fractures were not significantly different (p= 0.773). Sensory recovery was more rapid and better after orbital floor than after zygomaticomaxillary fractures; however, the difference was not significantly different. Additionally, the low-energy group showed a higher incidence of sensory changes than the high-energy group, but the difference was not statistically significant (p= 0.512). Permanent sensory changes were more frequent in the high-energy group, the difference was statistically significant (p= 0.043).

CONCLUSION

The study found no significant difference in the incidence of sensory changes associated with orbital floor and zygomaticomaxillary fractures. In case of orbital floor fractures and high-energy injuries, the risk of permanent sensory impairment should be considered.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

DISCUSSION

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

Intraoperative cone beam assessment after reduction of zygomatic fractures helps in taking a decision on associated orbital floor fractures

INTRODUCTION

Orbital floor fracture (OFF) are frequently associated with zygomatic fractures (ZF). The reduction of the ZF may modify the features of the associated OFF. Intraoperative cone beam CT (CBCT) has shown diagnostic performance of OFF. The aim of our study was to evaluate how intraoperative CBCT control made after the reduction of ZF may help to take a decision on the associated OFF.

MATERIAL AND METHOD

Patients with a unilateral displaced ZF associated with an OFF were consecutively included during a 3-year period. Intraoperative CBCT, systematically performed after reduction of the ZF, allowed to decide if the OFF needed reconstruction. The preoperative estimation made on MDCT and the intraoperative decision regarding the OFF were compared.

RESULTS

Fifty-nine consecutive patients could be included in the study. Nineteen OFF were presumed to be surgical indications on the preoperative MDCT but only 16 indications were confirmed on the intraoperative CBCT, meaning that 3 OFF behaved favorably during the ZF reduction. Forty orbital floor fractures were presumed to be non-surgical on the preoperative MDCT but 6 of them worsened during ZF reduction and became surgical indications. Overall, the intraoperative CBCT control had an impact on 9 (15.3%) of the OFF.

CONCLUSION

Our study showed that OFF after ZF reduction may evolve favorably or, on the contrary, get worse in 15% of the cases. Surgical indication on an OFF can therefore be confirmed intraoperatively. This allows to avoid under-treatment in the patients where the OFF worsens after ZF reduction and over-treatment in the patient where the OFF reduces after ZF.

Quantitative analysis of soft tissue sagging after lateral midface fractures: A 10-year retrospective study

BACKGROUND

Lateral midface fractures occasionally require open reduction and internal fixation to restore function and facial symmetry. However, some patients retain facial asymmetry despite undergoing surgery due to hard tissue displacement or soft tissue sagging. This study aimed to determine the influence of soft tissue sagging on the postoperative facial symmetry.

METHODS

We examined the medical records of 590 patients who underwent planned plate removal after lateral midface or zygomatic bone fractures. After applying the inclusion and exclusion criteria, we analyzed 106 cases of lateral midface fractures for hard tissue displacement and soft tissue sagging using pre- and postoperative radiological imaging and postoperative face scanning.

RESULTS

We observed significantly larger soft tissue sagging (p &lt; 0.001) and hard tissue displacement (p = 0.006) on the fractured side than on the non-fractured side. There was no correlation between differences in the soft tissue sagging and those in the hard tissue displacement (|rho|=0). Linear regression analysis showed no statistical influence of sex or age group on the soft tissue sagging and hard tissue displacement.

CONCLUSION

Therefore, we recommend treating soft tissue sagging as a discrete aspect of midfacial fracture treatment to achieve optimal postoperative facial symmetry. From a clinical perspective, we recommend better soft tissue management during open fracture treatment than focusing mainly on the reduction of bony hard tissues.

Post-traumatic tuberculosis of Zygoma - An uncommon presentation

Tubercular osteomyelitis of mid-facial bones is extremely rare because of its immense vascular supply. Due to rare incidence, myriad presentation, and lack of specific symptoms, this condition presents a challenge in diagnosis and calls for acute clinical awareness. This article presents a case report of a 31-year-old martial artist with complaints of trauma to his right malar region since one month and a gradually increasing swelling below his right eye for 3 weeks without any discharge. A diagnosis of primary Tuberculosis of right zygomatic bone was made with the help of multiple diagnostic tools. The patient was treated with four drug anti-tubercular therapy and responded with complete recovery from disease.

Three-dimensional soft tissue changes after reduction malarplasty in female patients

The aim of this study was to determine the three-dimensional soft tissue changes after reduction malarplasty. Soft tissue changes relative to the amount of movement of the zygomatic bone were studied. Pre- and postoperative cone beam computed tomography images of 21 female patients were superimposed. The anterior-most point of the body osteotomy (point A), arch osteotomy site (point D), and points dividing line A-D into thirds (points B and C) were marked on lateral view images. The vertical distances from the midsagittal line to the centre of the zygomatic bone and the outer prominence of the soft tissue were measured on the coronal view of each image. The proportion of the change in soft tissue to that of the bone before and after surgery was calculated for each point. The relationship between body mass index and the soft tissue change ratio, and the differences in soft tissue changes at each point were analysed. Mean soft tissue changes for points A, B, C, and D were 53.43%, 66.66%, 63.67%, and 57.23%, respectively. The amount of soft tissue change at point B was greater than that at points A and D, which were osteotomy sites. There was no statistical correlation between body mass index and the soft tissue change ratio at each point.

颧骨缺损不同修复重建方法和预后的回顾性分析

OBJECTIVE

To evaluate the effect and summarize the characteristics of different treatment methods in repairing zygomatic defect.

METHODS

A total of 37 patients with zygomatic defect were reviewed in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from August 2012 to August 2019. According to the anatomical scope of defect, the zygomatic defects were divided into four categories: Class 0, the defect did not involve changes in zygomatic structure or continuity, only deficiency in thickness or projection; Class Ⅰ, defect was located in the zygomatic body or involved only one process; Class Ⅱ, a single defect involved two processes; Class Ⅲa, referred to a single defect involving three processes and above; Class Ⅲb, referred to zygomatic defects associated with large maxillary defects. The etiology, defect time, defect size and characteristics of zygomatic defects, the repair and reconstruction methods, and postoperative complications were collected and analyzed. Postoperative computed tomography (CT) data were collected to evaluate the outcome of zygomatic protrusion. Chromatographic analysis was used to assess the postoperative stability.

RESULTS

Among the causes of defects, 25 cases (67.57%) were caused by trauma, and 11 cases (29.73%) were of surgical defects following tumor resection. We performed autologous bone grafts in 19 cases, 6 cases underwent vascularized tissue flap, 5 cases underwent external implants alone, and 7 cases underwent vascularized tissue flap combined with external implants. After the recovery of the affected side, the average difference of the zygomatic projection between the navigation group and the non-navigation group was 0.45 mm (0.20-2.50 mm) and 1.60 mm (0.10-2.90 mm), with a significant difference (P=0.045). Two patients repaired with titanium mesh combined with anterolateral thigh flap had obvious deformation or fracture of titanium mesh; 2 patients with customized casting prosthesis had infection after surgery and fetched out the prosthesis finally.

CONCLUSION

Autologous free grafts or alloplastic materials may be used in cases without significant structural changes. Pedicle skull flap or vascularized bone tissue flap is recommended for zygomatic bone defects with bone pillar destruction, chronic inflammation, oral and nasal communication or significant soft tissue insufficiency. Titanium mesh can be used to repair a large defect of zygomatic bone, and it is suggested to combine with vascularized bone flap transplantation.

Reduction malarplasty using a simulated surgical guide for asymmetric/prominent zygoma

Background

The present study introduces a reduction malarplasty using a three-dimensional (3D)-printed surgical guide and evaluates the guide’s technical applicability.

Methods

Twenty malarplasties were performed for 12 subjects with zygomatic asymmetry/prominency using the current method. 3D reconstruction of the craniomaxillofacial region and fine dental occlusion was made with image data from computed tomograpy and dental scanning. A computer-assisted surgical simulation was performed for reduction malarplasty and a surgical guide was designed for later 3D printing. The manufactured surgical guide was introduced to the operation field to guide the surgery; its surgical accuracy was confirmed by comparing five corresponding points from preoperative simulation and postoperative data.

Results

We successfully performed the reduction malarplasty with the surgical guide. The accuracy level of surgery fell to 0.93 mm of total median difference for the corresponding zygoma points of preoperative simulations and postoperative zygoma. The anterior and upper points showed less error level (0.59 and 0.73 mm difference, respectively) than did other points.

Conclusions

We developed a computer-assisted surgical technique using a surgical guide for asymmetrical/prominent zygoma which proved to be simple, practical, and accurate; it is expected to help surgeons perform reduction malarplasty with ease and accuracy.

Reliability and accuracy of dynamic navigation for zygomatic implant placement

Objectives

To assess the accuracy of a real‐time dynamic navigation system applied in zygomatic implant (ZI) surgery and summarize device‐related negative events and their management.

Material and methods

Patients who presented with severely maxillary atrophy or maxillary defects and received dynamic navigation‐supported ZI surgery were included. The deviations of entry, exit, and angle were measured after image data fusion. A linear mixed‐effects model was used. Statistical significance was defined as p < .05. Device‐related negative events and their management were also recorded and analyzed.

Results

Two hundred and thirty‐one zygomatic implants (ZIs) with navigation‐guided placement were planned in 74 consecutive patients between Jan 2015 and Aug 2020. Among them, 71 patients with 221 ZIs received navigation‐guided surgery finally. The deviations in entry, exit, and angle were 1.57 ± 0.71 mm, 2.1 ± 0.94 mm and 2.68 ± 1.25 degrees, respectively. Significant differences were found in entry and exit deviation according to the number of ZIs in the zygomata (p = .03 and .00, respectively). Patients with atrophic maxillary or maxillary defects showed a significant difference in exit deviation (p = .01). A total of 28 device‐related negative events occurred, and one resulted in 2 ZI failures due to implant malposition. The overall survival rate of ZIs was 98.64%, and the mean follow‐up time was 24.11 months (Standard Deviation [SD]: 12.62).

Conclusions

The navigation‐supported ZI implantation is an accurate and reliable surgical approach. However, relevant technical negative events in the navigation process are worthy of attention.

Modified Orbitozygomatic Approach for Resecting a Parasellar Tumor in a Single Institution

Background

Modified orbitozygomatic craniotomy is characterized by simplicity and wide exposure. The purpose of the present study was to describe a modified orbitozygomatic approach without resecting the zygomatic arch for large parasellar tumor surgeries.

Methods

Between April 2016 and December 2019, seven patients with parasellar tumor underwent surgiest with a modified orbitozygomatic approach. Surgical procedures, clinical outcomes, and complications were analyzed.

Results

This study included 3 meningiomas, 2 pituitary adenomas, 1 chondrosarcoma, and 1 schwannoma. Modified orbitozygomatic craniotomy provides a wider surgical freedom in the opticocarotid and prechiasmatic cistern than frontotemporal craniotomy without orbitotomy, Total, subtotal, and partial resections were achieved for 3, 2, and 2 patients, respectively. Reasons for partial resections were tight adhesion to the carotid artery and encasing of the carotid artery. Permanent morbidities developed in one patient with 3rd nerve palsy and one patient with hemiparesis.

Conclusion

Modified orbitozygomatic approach can provide the shortest access to the interpeduncular cistern with a minimum brain retraction. Surgeons who experience surgical challenge during the conventional approach for parasellar tumor resection are recommended to learn the modified orbitozygomatic approach.

A prospective cohort study

The aim of this study was to evaluate the value of intraoperative conebeam computed tomography (CBCT) imaging in the treatment of zygomaticomaxillary complex (ZMC) fractures. A prospective single center cohort study was performed. Included were consecutive patients who underwent surgery for a unilateral ZMC fracture. An intraoperative CBCT scan was performed after reduction of the ZMC fracture. Revision reduction was performed of the ZMC and/or orbital floor (OF) on indication. The preoperative and postoperative asymmetry of the outer surface of the ZMC was measured on digital 3D-models of CBCT scans, using a mirroring and surface-based matching technique. The postoperative asymmetry of the ZMC in the study group was compared to the asymmetry of the ZMC in the control group with healthy individuals. A total of 38 patients with a unilateral ZMC fracture were included. The mean postoperative asymmetry in the study group (1.67 mm, SD 0.89) was less than the mean preoperative asymmetry (2.69 mm, SD 0.95) (paired samples T-test p < 0.01) but showed no statistically significant difference with the mean asymmetry in the healthy control group (1.40 mm, SD 0.54) (independent samples T-test p = 0.31). Revision reduction of the ZMC and/or OF fracture had been performed in 11 cases after malalignment was noted on the intraoperative CBCT. The indication for intraoperative revision reduction was associated with comminuted ZMC fractures and/or fractures with indication for OF reduction (Pearson Chi Square p < 0.01). Within the limitations of the study, intraoperative CBCT imaging seemed to have a positive influence on ZMC fracture treatment, especially in the case of comminuted ZMC fractures and/or fractures with indication for OF treatment.

Success of day-case treatment of zygomatic and orbital fractures

Traditionally, surgical management of zygomaticomaxillary complex (ZMC) and orbital fractures occurs within two to three weeks of the injury, followed by an overnight admission to allow for extended eye observations. This is due to the risk of postoperative retrobulbar haemorrhage (RBH) or orbital compartment syndrome (OCS), a rapidly progressive and sight threatening emergency that requires immediate intervention. In September 2016 the oral and maxillofacial surgery (OMFS) department at Leeds Teaching Hospitals redesigned their trauma service with a full-time trauma consultant, a dedicated clinic, and a weekly morning elective trauma theatre list. This allowed for standardisation of the management of patients with OMFS injuries. Furthermore, a formal day-case ZMC and orbital fracture pathway was developed to allow patients to undergo surgical management of such fractures with a same-day discharge. This has since been identified as an area of excellence by the Getting It Right First Time (GIRFT) programme, and is in line with the addition of ZMC and orbital fractures to the procedural list written by the British Association of Day Case Surgery (BADS). Unbeknown to the unit, the volume of day-case procedures was the highest within the UK, demonstrating the importance of GIRFT in highlighting areas of good or unique practice. The aim of this study was to determine the impact of our day-case pathway and designated OMFS trauma service on compliance with recent recommendations by GIRFT and BADS. Secondly, it was to determine the safety of same-day discharge with regards to postoperative complications.

A zygomatic bone study using virtual dental implant planning software

This study evaluated the anatomical factors that influence the virtual planning of zygomatic implants by using cone beam computerized tomography (CBCT) scans. CBCT scans of 268 maxilla edentulous patients were transferred to a specialized implant planning software (Galaxis, Sirona) for the following measurements: maxillo-sinus concavity size (small, medium, and large), Zygoma width, implant insertion angle, implant length, and implant apical anchorage. Concavity sizes found were as follows: 34.95% small, 52.30% medium, and 7.35% large. The mean insertion angle was 43.2 degrees and the average implant apical anchorage was 9.1mm. The most frequent implant length was 40mm. Significant differences were found when the different types of concavities in relation to the installation angle, the distance of the apical portion of the implant in contact with the zygomatic bone and the lateral-lateral thickness of the zygomatic bone were compared (p<0.001). Medium-sized maxillary sinus concavity presented greater apical anchorage of the implant (9.7mm) and was the most frequent type (52.30%). The zygomatic bone is a viable site for zygomatic fixtures and the use of specialized implant planning software is an important tool to achieve predictable outcomes for zygomatic implants and allows good visualization of the implant-anatomical structures relation.

Intramuscular hemangioma in the zygomaticus minor muscle: a case report and literature review

Intramuscular hemangioma is a rare vascular benign proliferation that can occur within any muscle, particularly in the trunk and extremities. In the head and neck region, the masseter muscle is most commonly involved, followed by the periorbital and sternocleidomastoid muscles. Diagnosing intramuscular hemangioma is challenging because there are no characteristic symptoms; instead, magnetic resonance imaging is the best imaging modality to diagnose these lesions. Complete surgical resection is the treatment of choice, although the local recurrence rate is high. Herein, we report a rare case of intramuscular hemangioma located in the zygomaticus minor muscle, which is related to smiling and usually runs along the orbicularis oculi muscle. Distinguishing or separating these two muscles is challenging. However, based on the muscle vector of the midface and radiological findings, the two muscles were successfully separated. The zygomaticus minor was cut very slightly to approach to the lesion and the muscle fibers were split to excise it. A follow-up examination revealed no nerve damage or muscle dysfunction at 4 weeks postoperatively. This rare case may serve as a reference for managing intramuscular hemangioma in the head and neck region.

The difference in the location of the malar summit between genders in Southeast Asians with appropriate references

Background

Facial feminization surgery and malarplasty require information concerning facial features in the malar area. Such information varies as a function of sex and race. The objectives of this study aimed to quantitatively evaluate the location of malar prominence across sexes in the Southeast Asian population, and identify sex-specific differences in malar prominence using a combination of two-dimensional (2D) computed tomography (CT) and three-dimensional (3D) CT.

Methods

The location of malar prominence was evaluated in 101 Thai adults, consisting of 52 men and 49 women. This study used both 2D CT and 3D CT to achieve greater accuracy, in which 2D CT was used to measure malar distance, malar summit width, facial width, and malar summit-to-facial width ratio whereas 3D CT was used to evaluate the positional relationship between the zygomatic summit and four reference points of the zygoma.

Results

The malar summit was positioned more laterally in males (p<0.01) and was more projected in females (p=0.01). The other 2D-parameters were wider in males. The ratio between the malar summit width and facial width showed similar results for both sexes. The vertical dimension did not show any statistically significant differences; however, a higher summit position was observed in males.

Conclusion

The zygomatic summit is positioned more laterally in males and is more projected in females. However, the ratio was similar, which indicates that the male cranium is larger in size. Based on the results in this study, when facial feminization surgery or malarplasty is performed on a Southeast Asian patient, the malar bone should be reduced horizontally and moved forward for better outcomes.

Central hemangioma of Zygoma - A rare case report with CT and MRI features

Intraosseous hemangiomas are uncommon, constituting less than 1% of all osseous tumors. The most frequent sites are the calvaria and the vertebral column. The involvement of the facial bones is rare, and if occurs, it can involve maxilla, mandible, nasal bones and zygomatic bone. Zygomatic hemangioma is a benign, slow-growing tumor occurring mostly in adult women. The radiographic findings are diagnostic. Total excision of the tumor with the primary reconstruction of the defect is the preferred treatment modality. Here, we are reporting a case of a 37-year-old woman who presented with a painless hard swelling in the right zygomatic prominence, which was diagnosed as intraosseous hemangioma after the radiological examination because of its characteristic radiological picture. An Excisional biopsy also proved the swelling to be a cavernous hemangioma.

Long transmaxillary implants improve oral health-related quality of life of patients with atrophic jaws-a case series

Background

The advancement of contemporary dentistry is related to the improvement of existing techniques, materials, and technology, consistently for improving people’s oral health, which can ultimately reflect better quality of life. This study aimed to evaluate the oral-health-related quality of life (OHRQoL) of patients with atrophic jaws, who reported for the placement of long transmaxillary implants and posterior prosthetic rehabilitation. Twelve patients (n = 12), of both sexes, with a mean age of 55.83 ± 2.78 years, who were unable to receive conventional implants immediately because of lack of bone, received two long transmaxillary implants in a horizontal position, anteroposteriorly, one on each side, from the canine pillar to the maxillary tuberosity. After 6 months, the conventional clinical sequence for fabricating a fixed prosthesis type protocol or removable prosthesis type overdenture (MK1® system) was performed, when required to recover the lip volume. The Oral Health Impact Profile questionnaire (OHIP-14) was applied preoperatively and 6 months after rehabilitation using a prosthesis on the implants. The results were statistically analyzed using a significance level of 0.05.

Results

An improvement in the perception of OHRQoL was observed between the pre- and postoperative periods in the OHIP-14 total score and the domains related to functional limitation, physical pain, psychological discomfort, psychological disability, social disability, and handicap (p < 0.05).

Conclusion

It may be concluded that transmaxillary implant rehabilitation improves the OHRQoL.

Inferomedially impacted zygomatic fracture reduction by reverse vector using an intraoral approach with Kirschner wire

Background

In inferomedially rotated zygomatic fractures sticking in the maxillary sinus, it is often difficult to achieve complete reduction only by conventional intraoral reduction. We present a new intraoral reduction technique using a Kirschner wire and its clinical outcome.

Methods

Among 39 inferomedially impacted zygomatic fractures incompletely reduced by a simple intraoral reduction trial with a bone elevator, a Kirschner wire (1.5 mm) was vertically inserted from the zygomatic body to the lateral orbital rim in 17 inferior-dominant rotation fractures and horizontally inserted to the zygomatic arch in nine medial-dominant and 13 bidirectional rotation fractures. A Kirschner wire was held with a wire holder and lifted in the superolateral or anterolateral direction for reduction. Following reduction of the zygomaticomaxillary fracture, internal fixation was performed.

Results

Fractures were completely reduced using only an intraoral approach with Kirschner wire reduction in 33 cases and through an additional lower lid or transconjunctival incision in six cases. There were no surgical complications except in one patient with undercorrection. Postoperative 6-month computed tomography scans showed complete bone union and excellent bone alignment. Four patients experienced difficulty with upper lip elevation; however, these problems spontaneously resolved after manual tissue lump massage and intralesional steroid (Triamcinolone) injection.

Conclusions

We completely reduced infraorbital rim fractures, zygomaticomaxillary buttresses, and zygomaticofrontal suture fractures in 84% of patients through an intraoral approach alone. Intraoral Kirschner wire reduction may be a useful option by which to obtain effective and powerful reduction motion of an inferomedially rotated zygomatic body.

Influence of glycemic control on survival of zygomatic implants in relation with type-2 diabetes mellitus: 10 years' follow-up results

It is hypothesized that under optimal glycemic control (GC), there is no difference in the survival of implants placed in the zygomatic bone of edentulous patient with and without type-2 diabetes mellitus (T2DM). Purpose: The aim was to assess the influence of GC on survival of implants placed in the zygomatic bone of edentulous patient with and without T2DM at 10-years' follow-up. Twenty patients with T2DM (10 with poorly- and 10 with well-controlled T2DM) and 12 patients without T2DM were included. Hemoglobin A1c (HbA1c) levels were recorded and demographic data was collected from all participants. Peri-implant inflammatory parameters (plaque index [PI], probing depth [PD], crestal bone loss [BL] and gingival index [GI]) were measured in all patients. Group comparisons were done and P-values, which were less than 0.01 were indicative of statistical significance. Twenty and 12 male patients with and without T2DM, respectively were included. Among patients with T2DM, 10 and 10 individuals had poorly- and well-controlled T2DM, respectively.  The mean HbA1c levels were significantly higher in patients with poorly- (9.2 ± 0.7%) compared with well-controlled T2DM (4.8 ± 0.3%) (P<0.01) and non-diabetic individuals (4.6 ± 0.3%) (P<0.01). The crestal BL on the mesial (P<0.01) and distal (P<0.01) surfaces, PD (P<0.01), PI (P<0.01), and GI (P<0.01) were significantly higher around all zygoma implants placed in patients with poorly-controlled T2DM compared with patients with well-controlled T2DM and patients without T2DM. These clinicoradiographic parameters were comparable around zygoma implants placed in patient with well-controlled T2DM and in subjects without T2DM.  Optimal glycemic control is essential for the long-term stability of zygomatic plants in patients with T2DM.

Impact of intraoperative cone beam computed tomography in the management of zygomatic fractures

AIM

To evaluate the impact of intraoperative cone beam computed tomography (CBCT) assessment for the surgical management of zygomatic bone fracture (ZF).

METHODS

A prospective study was conducted on patients operated on for unilateral ZF during a two-year period. Repositioning of the fractured zygoma was assessed intraoperatively by measuring the position of malar eminences in three dimensions on CBCT. A difference of more than 2 mm between both sides was considered significant and the reduction was judged inadequate. Surgical procedure was adapted to intraoperative imaging findings.

RESULTS

The surgical procedures of 47 patients treated for ZF were analyzed. In 15% of the cases (7 patients), the intraoperative CBCT showed an inadequate reduction while the morphological results seemed correct. Those patients benefited from an immediate correction of the reduction. From these 7 patients, reduction was optimized further without the need of osteosynthesis in one case, additional osteosynthesis was performed in 4 cases and 2 patients required both reduction and osteosynthesis revision.

CONCLUSION

Intraoperative CBCT control helps to achieve anatomic repositioning in case of ZF. It may reduce the risk of under-treatment and possible reoperation, and of over-treatment meaning systematic ORIF in all fractures.

[Accuracy and clinical outcome of a real-time surgical navigation system for the placement of quad zygomatic implants]

Objective: To evalute the accuracy and clinical outcome of a real-time navigation system for the placement of quad zygomatic implants. Methods: Twenty-four patients [9 males and 15 females, mean age was (50.8±14.7) years old], from January 2015 to December 2019, with 96 zygomatic implants placed under a real-time navigation system in Department of Second Dental Center and Department of Oral Implantology of Ninth People's Hospital, Shanghai Jiaotong University School of Medicine were included in the study. The preoperative and the postoperative multislice CT or cone-beam CT were fused to measure and record the entry, exit and angle deviation between the planned and placed implants. The implants were divided into groups according to implant insertion approach (real-time navigation and free-hand), implant length (<47.5 mm and ≥47.5 mm) and implant position (proximal and distal implant). And the differences of implant accuracy were analyzed. The intraoperative and postoperative complications were also recorded. The implant survival rate was evaluated after 6 months follow-up. A P value<0.05 indicates statistical significance. Results: The mean entry, exit and angle deviation of zygomatic implants were (1.49±0.64) mm, [2.03(1.58, 2.40)] mm and (2.49°±1.12°), respectively. The average entry, exit and angle deviation of the navigation guided implant insertion group were (1.45±0.60) mm, (1.96±0.44) mm and (2.66±1.13°) respectively, while those of the free-hand group were (1.50±0.64) mm, (2.04±0.79) mm and (2.50°±1.13°) respectively. There was no significant difference between the two groups (P>0.05). The average entry, exit and angle deviation of the group with length<47.5 mm were (1.42±0.60) mm, (2.13±0.60) mm and (2.61°±1.08°) respectively and those of the group with length ≥ 47.5 mm were (1.52±0.65) mm, (1.98±0.82) mm and (2.43°±1.14°) respectively. No significant difference was found between the two groups (P>0.05). In proximal implant group, the average entry, exit and angle deviation were (1.55±0.69) mm, (2.05±0.92) mm and (2.48°±1.16 °) respectively while those of distal implant group were (1.43±0.57) mm, (2.01±0.57) mm and (2.49°±1.10°), respectively. No significant difference was detected between the two groups (P>0.05). All zygomatic implants were placed uneventfully. There were no intra-operative complications, and post-operative reversible complications developed in 3 patients. Two zygomatic implants were lost and the overall zygomatic implant survival rate was 97.9% (94/96) within a follow-up of 6 months. Conclusions: Quad zygomatic implant placement can be achieved with high accuracy and predictable clinical outcome under guidance of a real-time navigation system.

Zygomatic air cells in connection with Luc's abscess

INTRODUCTION

An uncommon complication of Acute Otitis Media (AOM) is a subperiosteal temporal infection known as Luc's abscess. Zygomatic air cells (ZACs) are an uncommon anatomic variant.

CASE SERIES

Two otherwise healthy male patients, aged six- and thirteen years-old presented with unilateral otalgia, swelling, trismus, and fever. Imaging revealed Luc's abscess near ZACs. Antibiotics, drainage and myringotomy tubes resulted in a full recovery.

CONCLUSION

In addition to the spread of soft tissue infection through the Notch of Rivinus, the presence of ZACs may provide a pathway for suppurative effusion and development into Luc's abscess.

Zygomatic Implants: A Solution for the Atrophic Maxilla

Even with the great strides made in the techniques for placement of traditional endosseous dental implants, restoration of the dentition in patients with a severely resorbed or resected maxilla can prove challenging. For many decades, significant bone grafting was the mainstay of treatment for these patients. However, zygomatic implants have been shown to provide a stable and predictable alternative for the restoration of the dentition for patients with severe bone loss of the maxilla.

[Research progress in zygomatic implant technique]

Zygomatic implant technique is an effective alternative for the prosthetic rehabilitation of maxilla with severe bone defect exteriorly and functionally, which not only avoid bone grafting and shorten the prosthetic process in some way, but also improve the prognosis quality of patient, as well as the pronunciation and the chew function. With the popularity in the clinic, zygomatic implants have been developed these years. This article will give a systematical introduction including the update of the application of the technology, as well as the selection of the quantity and location of the implants, the modifications of the operation technique, the avoidance and solution of common specific complications, the establishment of zygomatic implant index and the assistance of the computerized technique in the operation.

A study protocol for a randomised controlled trial evaluating the effects of intraoperative computed tomography on the outcomes of zygomatic fractures

Background

Zygomaticomaxillary complex (ZMC) and zygomatic arch (ZA) fractures are common injuries resulting from facial trauma and frequently require surgical management (Huang et al., Craniomaxillofac Trauma Reconstr 8(4):271-6, 2015). A substantial number of post-operative functional and cosmetic complications can arise from the surgical management of these fractures. These include scarring, inadequate facial profile restoration, facial asymmetries and diplopia (Ellis et al. J Oral Maxillofac Surg 54(4):386-400, 1996; Yang et al. Oral Maxillofac Surg Clin North Am 23(1):31-45, 2011; Kloss et al. Int J Oral Maxillofac Surg 40(1):33-7, 2011). Intuitively, most of these aforementioned complications arise as a result of inadequate fracture reduction; however, current standard practice is to assess reduction post-operatively through plain radiographs or computed tomography (CT) scans. The role of intra-operative CT scanning to assess the reduction of ZMC/ZA fractures and the potential impact on complications, has thus far not been established.

Methods

This is a prospective randomised controlled trial currently being undertaken at the Royal Brisbane and Women’s Hospital. All patients who require operative management of their ZMC or ZA fractures are offered enrollment in the trial. The patients are randomised into two groups: interventional (intra-operative CT) and control (no intra-operative CT). All patients in each group will have post-operative radiographs taken. From these radiographs, the reduction of the ZMC and/or ZA fracture is graded by a blinded assessor. Patients will be reviewed in clinic at 1 week and 6 weeks post-surgery. During these consultations, all patients will be assessed for scarring, diplopia, facial profile restoration and need for revision surgery.

Discussion

Many complications associated with surgical management of ZMC and ZA fractures involve poor aesthetic results as a direct consequence of inadequate fracture reduction. Inadequate fracture reduction is predictable given that small incisions are used and only limited visualisation of the fractures is possible during the procedure. This is due to a desire to limit scarring and reduce the risk of damage to vital structures in an aesthetically sensitive region of the body. It follows that an intraoperative adjunctive tool such as a CT scan, which can assist in visualisation of the fractures and the subsequent reduction, could potentially improve reduction and reduce complications.

Trial registration

Australian New Zealand Clinical Trials Registry, ACTRN12616000693426. Registered on 26 May 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3625-8) contains supplementary material, which is available to authorized users.

The "European zygomatic fracture" research project: The epidemiological results from a multicenter European collaboration

PURPOSE

Fractures of the zygomaticomaxillary complex (ZMC) are common injuries that may lead to loss of an aesthetically pleasing appearance and functional impairment. The aim of this study was to analyze the demographics, causes, characteristics, and outcomes of zygomatic fractures managed at several European departments of oral and maxillofacial surgery.

MATERIALS AND METHODS

This study is based on a multicenter systematic database that allowed the recording of all patients with ZMC fractures between 1 January 2013 and 31 December 2017. The following data were recorded: gender, age, personal medical history, etiology, side of zygomatic fracture, classification of ZMC fracture, associated maxillofacial fractures, symptoms at diagnosis, type of performed treatment, and sequelae/complications.

RESULTS

A total of 1406 patients (1172 males, 234 females) were included in the study. Statistically significant correlations were found between assault-related ZMC fractures and the A3 class (p < .0000005) and between Infraorbital Nerve (ION) anesthesia and B class (p < .00000005).

CONCLUSION

The most frequent cause of ZMC fractures was assault, followed by falls. The most frequently involved decade of age was between 20 and 29 years. The decision and type of surgical treatment of ZMC fractures depends on several issues that need to be considered on a case by case basis.

Revision malarplasty guided by strategic categorization

BACKGROUND

Esthetic reduction malarplasty is popular in East Asia, where a small and balanced facial profile is considered a desirable characteristic. Various surgical techniques have been applied; however, several complications can impact the bony structure and final esthetic appearance. We examined the outcomes of revision malarplasty with regard to strategic assessments to achieve facial balance and skeletal stability.

METHODS

This retrospective study reviewed 97 patients who underwent revision malarplasty between December 2014 and November 2016. We analyzed the indications of revision and categorized the patients into three surgical groups. Dual bone flap procedures utilizing new osteotomies were performed to achieve a natural malar contour in certain cases. In addition, zygomatic arches were fixed in a lifted position to revise both bony dehiscence and soft tissue drooping. Postoperative results were assessed using medical records, photographs, and facial bone computerized tomography images.

RESULTS

The major reason for revision malarplasty was undercorrection that required additional repositioning. The zygomatic body and arch with a bony gap (5-7 mm) necessitated additional osteotomy and repositioning to achieve zygomatic continuity and natural curvature. Significant bony defects and segmental resorption were addressed with reconstructive bone grafts.

CONCLUSION

The causes of complications after malarplasty should be cautiously evaluated before revision procedures. We categorized patients on the basis of strategic analysis considering reposition vector and the necessity of additional osteotomy. Unstable zygomatic segments were revised to obtain structural stability, and the zygomatic arch lifting technique using an intraoral approach can be used to achieve promising and predictable outcomes in revision malarplasty.

Do Infield Softball Masks Effectively Reduce Facial Fracture Risk?

Infield softball masks are intended to reduce facial fracture risk, but are rarely worn. The objective of this study was to evaluate the effectiveness of infield masks’ ability to attenuate facial fracture risk over a range of designs and materials. To simulate batted ball impacts, a customized pitching machine was used to propel softballs at 24.6 ± 0.51 m/s. The balls impacted locations centered over the maxilla and zygoma bones of a FOCUS headform. The FOCUS headform was attached to a 50th percentile Hybrid III neck and secured to a slider table. Facial fracture risk of each facial bone was compared between masks and impact locations using peak resultant forces. Analysis of these data showed that the mask material and the distance between the mask and the impacted facial bone were key factors in determining a mask’s performance. The effectiveness of masks varied. It was found that a metal mask with a separation distance ≥ 35 mm away from the maxilla and ≥ 25 mm away from the zygoma best reduced facial fracture risk for these test configurations. Plastic masks performed worse because they excessively deformed allowing ball contact with the face. This study assesses various mask designs for their ability to reduce facial fracture and suggests design recommendations based on the impact configurations tested.

Open reduction of zygoma fractures with the extended transconjunctival approach and T-bar screw reduction

Background

Zygomaticomaxillary complex (ZMC) fractures mostly occur in the form of tripod fractures. The surgical field is accessed using a combination of three classic approaches. However, the subciliary incision may have unfavorable aesthetic results. Herein, the authors report the advantages of the extended transconjunctival approach (ETA) combined with T-bar screw reduction in minimizing scarring and complications for the treatment of ZMC fractures.

Methods

A total of 26 patients underwent ZMC reduction through the ETA and intraoral approach. A skin incision measuring roughly 5 to 8 mm in length was placed following the lateral canthal skin crease. After releasing the inferior crus of the lateral canthal tendon for canthotomy, the medial periosteum of the lateral orbital rim was preserved for canthal reattachment. A limited subperiosteal dissection and partial relaxing incision of the orbicularis oculi were performed to expose the fracture line of the inferior orbital rim and zygomaticofrontal suture. Reduction was performed using a T-bar screw through the transconjunctivalincision and an elevator through the intraoral incision.

Results

The aesthetic and functional results were excellent. Successful reduction was achieved and the skin incision was less than 8 mm in 20 cases (76.9%). Only six patients had an additional skin incision (less than 5 mm) to achieve reduction. No cases of ectropion, entropion, or excessive scarring were noted.

Conclusions

The ETA using a T-bar screw is a useful method for maximizing aesthetic results in ZMC fractures, with the advantages of minimal scarring, faster recovery, and maintenance of pretarsal fullness.

Modified Orbitozygomatic Approach without Orbital Roof Removal for Middle Fossa Lesions

Objective

The purpose of the present study was to describe an OrBitoZygomatic (OBZ) surgical variant that implies the drilling of the orbital roof and lateral wall of the orbit without orbitotomy.

Methods

Design : cross-sectional study. Between January 2010 and December 2014, 18 patients with middle fossa lesions underwent the previously mentioned OBZ surgical variant. Gender, age, histopathological diagnosis, complications, and percentage of resection were registered. The detailed surgical technique is described.

Results

Of the 18 cases listed in the study, nine were males and nine females. Seventeen cases (94.5%) were diagnosed as primary tumoral lesions, one case (5.5%) presented with metastasis of a carcinoma, and an additional one had a fibrous dysplasia. Age ranged between 27 and 73 years. Early complications were developed in four cases, but all of these were completely resolved. None developed enophthalmos.

Conclusion

The present study illustrates a novel surgical OBZ approach that allows for the performance of a simpler and faster procedure with fewer complications, and without increasing surgical time or cerebral manipulation, for reaching lesions of the middle fossa. Thorough knowledge of the anatomy and surgical technique is essential for successful completion of the procedure.

Ophthalmological injuries associated with fractures of the orbitozygomaticomaxillary complex

Our aim was to evaluate ophthalmological injuries associated with fractures of the orbitozygomaticomaxillary complex that required operative treatment, and we collected data retrospectively over a period of five years (2012-2016 inclusive). Of the 190 patients, 162 were male with a median age of 31 (IQR 25 -39) years. Assault was the most common mechanism of injury (125/190, 66%). Minor ophthalmic injuries (those unlikely to cause permanent visual disturbance) and major ophthalmic injuries (those with the potential to cause permanent visual disturbance) were recorded. The common minor ophthalmic injuries were: diplopia, enophthalmos, proptosis, subconjunctival haemorrhage, and restriction of the extraocular muscles. Commotio retinae, traumatic mydriasis, retro-orbital haemorrhage, and hyphaema were the common major ophthalmic injuries. All 13 different major ophthalmic injuries were recorded in the group who had had orbital fractures reconstructed, which suggested that more intraocular damage can be caused by this type of fracture than by others. Visual acuity was reduced in 26/190 patients with only four having persistent postoperative changes at six weeks. The odds ratio for those patients who had a major ophthalmological injury and were unable to drive was 0.07 (95% CI 0.02 to 0.21, p=0.001), which was highly significant. Ophthalmological assessment is strongly recommended for patients with fractures of the orbitozygomaticomaxillary complex.

Management of Zygomaticomaxillary Complex Fractures

Zygomaticomaxillary fractures account for approximately 25% of all facial fractures. They can be grouped into high-velocity and low-velocity injuries. A complete head and neck examination is critical for accurate clinical diagnosis. A thin-cut axial CT scan with sagittal, coronal, and 3-D reconstruction is important for accurate diagnosis and treatment planning. A thorough understanding of bony tetrapod anatomy and fracture mechanics is critical to treatment planning. Treatment options include closed and open reduction with internal fixation. Computer-aided applications can reduce the need for open reduction and improve the accuracy of both closed and open repairs.

Primary One Stage Reconstruction in Complex Facial Avulsion Injury

Complex facial injuries with soft tissue degloving and bony avulsion are very devastating to the patient. Partial degloving injuries are described but hemifacial degloving with zygoma avulsion are rare. The author presents a case of post-traumatic degloving of the left upper lip, nose, part of forehead, upper and lower eyelids and cheek with avulsion of the left zygoma. The management included immediate resuscitation and early surgery to reposition the skeletal as well as soft tissue avulsion. The wound was thoroughly washed and primary repositioning and fixation were done. Early one stage surgery with meticulous debridement and alignment of the anatomical landmarks results in very good aesthetic and functional outcome.

Ophthalmic outcomes of fractured zygomas

In patients with fractures of the zygomatic complex, computed tomography (CT) often identifies extensive defects in the orbital floor. Some surgeons recommend routine exploration and repair of these defects during repair of the zygoma, while others advocate a more selective approach, but there is a paucity of evidence either way. We report a retrospective case series of 50 patients who had open reduction and internal fixation of zygomatic fractures by a single surgeon in the maxillofacial department at the John Radcliffe Hospital, Oxford, between 2011and 2014. The orbit was repaired only in those with severe diplopia, or restriction or malpositioning of the globe. Patients were evaluated by age, sex, aetiology, preoperative findings including diplopia and ocular malpositioning, fracture pattern, and morbidity. A total of 14 had preoperative ophthalmic signs. In five these were minimal so treatment was conservative. Nine (eight with diplopia and one with a malpositioned globe) had exploration and seven of them had the orbit repaired at the same time as the zygoma. This was not possible in the remaining two because of the complexity of the defect. There were no postoperative ophthalmic signs in the 41 who did not have orbit explored, or in the seven who had it repaired, and residual signs resolved after planned secondary reconstruction in the remaining two. We recommend that the orbit is explored only in patients with severe diplopia, or restriction or malpositioning of the globe.