Evaluation of Different Fixation Methods Combinations After L-Shaped Osteotomy Reduction Malarplasty: An In Vitro Biomechanical Study.

BACKGROUND: This in vitro study compared the stability of different fixation method combinations for the zygomatic complex after simulated L-shaped osteotomy reduction malarplasty, a common facial contouring surgery in East Asia with high postoperative complications due to poor fixation methods. MATERIALS AND METHODS: The study used 108 zygoma replicas with various fixation methods combinations in the zygomatic body (L-shaped plate with short wing on zygoma and on the maxilla, two bicortical screws, one bicortical screw with L-shaped plate, square plate, and rectangular plate) and zygomatic arch (Mortise-Tenon structure, 3-hole plate, and Mortise-Tenon structure plus short screw). The failure force under incremental load was applied through the Instron tensile machine to a well-stabilized model using a rubber band simulating the masseter muscle and recorded the increasing force digitally. ANOVA test was used for comparison between recorded values (P < 0.05). RESULTS: The results showed that the most stable combination was a six-hole rectangular plate and a Mortise-Tenon structure plus one short screw (358.55 ± 51.64 N/mm2). The results also indicated that the placement vector of the fixation methods around the L-shaped osteotomy and the use of the two-bridge fixation method were important factors in enhancing the stability of the zygomatic complex. CONCLUSION: The study suggested that surgeons should choose appropriate fixation methods based on these factors to reduce postoperative complications and improve surgical outcomes. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

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.

Assessment of different treatment alternatives for patients with total maxillectomy.

PURPOSE: To assess the biomechanical advantages of combining zygoma and partial subperiosteal implants for maxillary reconstruction in severely atrophic maxillae, offering potential solutions to the challenges posed by traditional reconstruction methods. MATERIAL AND METHODS: A finite element analysis used a craniofacial model simulating a totally resected maxilla. Four treatment scenarios (SCs) were evaluated: SC-1, the quad zygoma approach; SC-2, two zygoma implants (ZIs) and a one-piece subperiosteal implant (SI); SC-3, two ZI and a two-piece SI; and SC-4, four ZI and a one-piece SI. Stress distributions on bone, implants, abutments, and metal frameworks were compared under occlusal forces. RESULTS: For the simulated bone regions under vertical and oblique forces, SC-4 values were higher than SC-1, while SC-2 and SC-3 values were comparable for pmax and pmin. In addition, SC-2 and SC-3 values were lower than those of SC-1 and SC-4. The most balanced von Mises stress values on the ZIsand were observed in SC-3 under vertical and oblique forces. Furthermore, lower von Mises stress values on the abutments were seen in SC-3 under oblique and vertical forces. Although the lower von Mises stress values on the metal frameworks at the lateral incisor and first premolar side were seen in SC-3, lower von Mises values were observed in SC-4 in the first molar region. CONCLUSIONS: Overall, this study suggests that combining zygoma and partial subperiosteal implants may be a promising approach for reconstructing severely atrophic maxillae. These implants may offer improved biomechanical properties compared to ZIs alone.

Retrospective cohort assessment of survival and complications of zygomatic implants in atrophic maxillae.

OBJECTIVES: To report on zygomatic implant (ZI) survival rate and associated complications through a longitudinal retrospective cohort assessment. MATERIAL AND METHODS: A total of 940 ZIs (rough: 781, machined: 159; immediate loading: 454, delayed loading: 486) and 451 standard implants (rough: 195, machined: 256; immediate loading: 58, delayed loading: 393) were placed in 302 adult patients with atrophic maxilla from December 1998 till September 2020. Following data collection reported complications were grouped based on their origin as infectious/ non-infectious biological and mechanical. Statistical analysis was performed to identify risk factors and preceding complications leading to implant loss (P < 0.05). RESULTS: The survival rate of ZI was found to be 89.9% and the average time between implant placement and an eventual loss was 4.8 years. The mean ZI follow-up period was 7.9 ± 4.9 years. Amongst the infectious biological complications, sinusitis was the most reported (n = 138) occurring at a mean follow-up time-point of 4.5 years, whereas infraorbital nerve hypoesthesia occurred more frequently in the non-infectious biological category (n = 8, meantime: 0.3 years). The prosthetic screw fracture was the most reported complication of mechanical origin (n = 29, meantime: 4 years). Furthermore, sinusitis, standard implant loss, zygomatic/peri-zygomatic region infection, and oroantral communication were significantly associated with ZI loss. CONCLUSIONS: ZI placement offered a high survival rate for the rehabilitation of severely atrophied maxilla with most losses occurring within the first 5 years at follow-up. The most frequently observed complication was sinusitis which tends to develop several years following implant placement.

Does maxillary sinus size affect the risk for zygomatic complex fractures?

The purpose of the study was to measure the maxillary sinus sizes in patients with and without zygomatic bone fractures. In this cross-sectional study computed tomography data of a case group of consecutive treated patients with displaced zygomatic bone fractures were compared to a control group with mandibular fractures. Maxillary sinus sizes were measured in width, height, depth, and volume. We compared sinus sizes between the case and control group, followed by a subgroup analysis of slightly and severely displaced fractures using T-tests. We identified 89 cases, thereof 46 with slightly and 43 with severely displaced fractures. The control group consisted of 110 patients. The mean sinus volume of the case group (19,313 mm3 ± 5237) was significantly larger than in the control group (17,645 mm3 ± 4760; p = 0.02). Subgroup analyses revealed that this difference in volume was more pronounced between patients with severely displaced fractures (20,354 mm3 ± 5416; p = 0.003) and the control group. In two-dimensional measures, only sinus height was significantly greater in the case group (37.41 mm ± 4.25 vs. 35.33 mm ± 4.88; p = 0.002). The same holds for the subgroup with severely displaced fractures (38.27 mm ± 3.91; p = 0.001). Sinus width and depth showed no significant differences between the groups. A maxillary sinus volume larger than 20,000 mm3 is a predictive risk factor for a displaced zygomatic bone fracture. Greater sinus height indicates a larger surface area of the zygomaticomaxillary buttress that decreases the resistance to facial trauma.

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.

Peri-zygomatic infection associated with zygomatic implants: A retrospective longitudinal cohort study.

OBJECTIVES: The main objective of this retrospective, longitudinal, cohort study was to describe the occurrence of peri-zygomatic infection (PZI) as a complication associated with zygomatic implant (ZI) placement in a period of 22 years. MATERIALS AND METHODS: A retrospective search was carried out in the department of oral and maxillofacial surgery of Saint John's hospital in Genk, Belgium. Patients that had a severely atrophic fully or partially edentulous maxilla, and at least one ZI placed, were included. RESULTS: A total of 302 eligible patients, underwent ZI surgery between 1998 and 2020. From a total of 940 ZI, 45 were associated with the development of PZI. PZI was located in the upper portion of the cheek in relation to the external corner of the eye, one or two centimeters under the lower lid. The total number of affected patients was 25 (8.3%), who had a mean age of 58.1 years. In this subset, PZI occurred in 15 cases on the right side, in eight cases on the left side, and in two cases bilaterally. Ultimately, 16 ZI were lost in the PZI site. The mean time since the implant placement to the diagnosis of PZI was 1.9 years (SD ±2.4) and to the ZI removal of 3.8 years (SD ±3.7). After implant removal, the PZI symptomatology dissipated in all patients. CONCLUSION: Peri-zygomatic infection should be informed to the patients as a possible complication after ZI placement. Once identified, it should be acknowledged as a risk factor for ZI failure.

Relevance of presenting risks of frailty, sarcopaenia and osteopaenia to outcomes from aneurysmal subarachnoid haemorrhage.

INTRODUCTION: Aneurysmal subarachnoid haemorrhage (aSAH) is a condition with significant morbidity and mortality. Traditional markers of aSAH have established their utility in the prediction of aSAH outcomes while frailty markers have been validated in other surgical specialties. We aimed to compare the predictive value of frailty indices and markers of sarcopaenia and osteopaenia, against the traditional markers for aSAH outcomes. METHODS: An observational study in a tertiary neurosurgical unit on 51 consecutive patients with ruptured aSAH was performed. The best performing marker in predicting the modified Rankin scale (mRS) on discharge was selected and an appropriate threshold for the definition of frail and non-frail was derived. We compared various frailty indices (modified frailty index 11, and 5, and the National Surgical Quality Improvement Program score [NSQIP]) and markers of sarcopaenia and osteopaenia (temporalis [TMT] and zygoma thickness), against traditional markers (age, World Federation of Neurological Surgery and modified Fisher scale [MFS]) for aSAH outcomes. Univariable and multivariable analysis was then performed for various inpatient and long-term outcomes. RESULTS: TMT was the best performing marker in our cohort with an AUC of 0.82, Somers' D statistic of 0.63 and Tau statistic 0.25. Of the frailty scores, the NSQIP performed the best (AUC 0.69), at levels comparable to traditional markers of aSAH, such as MFS (AUC 0.68). The threshold of 5.5 mm in TMT thickness was found to have a specificity of 0.93, sensitivity of 0.51, positive predictive value of 0.95 and negative predictive value of 0.42. After multivariate analysis, patients with TMT ≥ 5.5 mm (defined as non-frail), were less likely to experience delayed cerebral ischaemia (OR 0.11 [0.01 - 0.93], p = 0.042), any complications (OR 0.20 [0.06 - 0.069], p = 0.011), and had a larger proportion of favourable mRS on discharge (95.0% vs. 58.1%, p = 0.024) and at 3-months (95.0% vs. 64.5%, p = 0.048). However, the gap between unfavourable and favourable mRS was insignificant at the comparison of 1-year outcomes. CONCLUSION: TMT, as a marker of sarcopaenia, correlated well with the presenting status, and outcomes of aSAH. Frailty, as defined by NSQIP, performed at levels equivalent to aSAH scores of clinical relevance, suggesting that, in patients presenting with acute brain injury, both non-neurological and neurological factors were complementary in the determination of eventual clinical outcomes. Further validation of these markers, in addition to exploration of other relevant frailty indices, may help to better prognosticate aSAH outcomes and allow for a precision medicine approach to decision making and optimization of best outcomes.

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 edentulous patients were transferred to specialized implant planning software 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 9.1 mm. The most frequent implant length was 40 mm. 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 < .001). Medium-sized maxillary sinus concavity presented greater apical anchorage of the implant (9.7 mm) 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 relation between implants and anatomical structures.

Influence of Glycemic Control on the Survival of Implants Placed in the Zygomatic Bone of Edentulous Patients With and Without Type 2 Diabetes Mellitus: 10-Year 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). The aim was to assess the influence of GC on survival of implants placed in the zygomatic bone of an edentulous patient with and without T2DM at the 10-year follow-up. Twenty patients with T2DM (10 with poorly controlled T2DM and 10 with well-controlled T2DM) and 12 patients without T2DM were included. Hemoglobin A1c (HbA1c) levels were recorded, and demographic data were 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 .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 controlled T2DM (9.2 ± 0.7%) compared with well-controlled T2DM (4.8 ± 0.3%; P < .01) and nondiabetic individuals (4.6 ± 0.3%; P < .01). The crestal BL on the mesial (P < .01) and distal (P < .01) surfaces, PD (P < .01), PI (P < .01), and GI (P < .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 GC is essential for the long-term stability of zygomatic plants in patients with T2DM.

[Relationship between prognosis and different surgical treatments of zygomatic defects: A retrospective study].

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.

A 3D finite element analysis of maxillary molar distalization using unilateral zygoma gear and asymmetric headgear.

OBJECTIVE: The aims of this study were (a) to evaluate the displacement and stress distribution in the maxillary dentition associated with the use of two different unilateral distalization appliances-unilateral zygoma gear (UZG) appliance and asymmetric headgear (AHG)-in non-growing patients; and (b) to assess the effects of fully erupted maxillary third molars on the distalization of the first molar with both appliances by using three-dimensional finite element analysis. SETTINGS AND SAMPLE POPULATION: Two 3D models of the maxilla were created: one with third molars and one without. Next, two distalizing appliances (UZG and AHG) were added to each model to create four models. MATERIALS AND METHODS: Distalization forces were applied, and the resultant displacements were recorded at the mesiobuccal and distolingual cusps and palatal root apex of each molar and the incisal edge root apex of the central incisors. The resulting von Mises stress distributions were evaluated. RESULTS: With the UZG, the first molar showed greater root distalization than the crown in the model with the third molar, whereas the model without the third molar showed distalization and distal tipping of the first molar. With the AHG, the first molar showed a large amount of distal tipping in the model without a third molar. However, this tipping was less than that in the model with third molars. CONCLUSION: The presence of completely erupted third molars decreased the amount of uncontrolled distal tipping in both appliances. UZG can be considered as an effective option for maxillary molar distalization.

Postoperative discomfort after implant placement according to the All-on-4 concept with or without Zygoma implants: A prospective clinical study.

OBJECTIVES: The purpose of the study was to assess patients' postoperative discomfort after implantations according to the All-on-4 concept with and without using Zygoma implants. MATERIAL AND METHODS: Three treatment groups were formed for this prospective study: All-on-4 rehabilitation in the maxilla (group 1, N = 25), All-on-4 rehabilitation in the maxilla using at least two Zygoma implants (group 2, N = 25), and All-on-4 rehabilitation in the mandible (group 3, N = 20). Principal outcome parameters were postoperative pain (100 mm VAS) and perceived swelling (100 mm VAS). Also, the use of analgesics was documented. RESULTS: The worst postoperative pain of 21.3 (SD 18.9) VAS was observed in group 2, but there was no statistically significant difference between the groups (mixed ANOVA p = .791). The postoperative total intake of painkillers was significantly higher in group 2 than in the other groups (p < .001). On postoperative day 28, the mean pain scores in all groups declined to values below 5 VAS. Postoperative perceived swelling in group 2 was significantly more severe than it was in group 1 and 3 (p < .001). CONCLUSIONS: The use of Zygoma implants in All-on-4 surgical interventions had an essential effect on postoperative swelling, but less so on postoperative pain. The slightly increased, but statistically not significantly different postoperative pain in group 2 was compensated by an overall higher postoperative intake of painkillers compared to the other groups.

Infraorbital foramen localization in orbitozygomatic fractures: a CT study with intraoperative finding.

OBJECTIVE: The aim of this study was to assess the infraorbital foramen (IOF) using CT in patients with Zygomaticomaxillary complex (ZMC) fractures (midface fracture). PATIENTS AND METHODS: This prospective study was carried out on 49 patients had ZMC fractures (98 sides) and 27 patients (54 sides) with craniomaxillofacial fractures rather than fractured ZMC as a control. Using CT, position of IOF was documented on 3D view in relation to inferior orbital rim, tooth root relation and finally with a novel imaginary line passing between anterior nasal spine and whitnall tubercle. RESULTS: Position of IOF had fixed anatomical landmark: just lateral to a line drawn between the anterior nasal spine to whitnall tubercle (clinically between nasal tip-lateral canthal ligament) and lateral to vertical plane to root of maxillary canine also with variable distance from inferior orbital rim ranged from 4.56 to 18.03 mm with a mean of 7.9 ± 2.447 mm. CONCLUSION: Even though ZMC fractures disturb the anatomical location of the ZMC bones, there are still preserved reliable fixed landmarks maxillofacial surgeons can depend on to identify and preserve ION.

Zygomatic bone shape in intentional cranial deformations: a model for the study of the interactions between skull growth and facial morphology.

Intentional cranial deformations (ICD) were obtained by exerting external mechanical constraints on the skull vault during the first years of life to permanently modify head shape. The repercussions of ICD on the face are not well described in the midfacial region. Here we assessed the shape of the zygomatic bone in different types of ICDs. We considered 14 non-deformed skulls, 19 skulls with antero-posterior deformation, nine skulls with circumferential deformation and seven skulls with Toulouse deformation. The shape of the zygomatic bone was assessed using a statistical shape model after mesh registration. Euclidian distances between mean models and Mahalanobis distances after canonical variate analysis were computed. Classification accuracy was computed using a cross-validation approach. Different ICDs cause specific zygomatic shape modifications corresponding to different degrees of retrusion but the shape of the zygomatic bone alone is not a sufficient parameter for classifying populations into ICD groups defined by deformation types. We illustrate the fact that external mechanical constraints on the skull vault influence midfacial growth. ICDs are a model for the study of the influence of epigenetic factors on craniofacial growth and can help to understand the facial effects of congenital skull malformations such as single or multi-suture synostoses, or of external orthopedic devices such as helmets used to correct deformational plagiocephaly.

Revision Surgery for Zygoma Reduction: Causes, Indications, Solutions, and Results from a 5-Year Review of 341 Cases.

BACKGROUND: Many patients undergo a revision surgery after malar reduction, which is one of the most popular aesthetic surgeries in Asia. We reviewed the leading causes of revision for malar reduction surgery to establish proper indications for revision, seek adequate surgical strategies, and share the results from revision surgical cases. METHODS: A retrospective review was conducted involving 341 patients who underwent malar reduction reoperation between March 2010 and June 2015. Surgical strategies were decided based upon specific problems and complaints from the previous surgery. Facial photographs, cephalography, and computed tomography images were analyzed, and a patient satisfaction survey was conducted before and after the surgery. RESULTS: A total of 341 patients (321 women, 20 men; average age, 26.6 years, range 18-40 years) were included. The main causes of reoperations were subjective dissatisfaction and nonunion-related symptoms. Undercorrection of the zygomatic body and arch (n = 175, 51.3%) was the most frequent reason for dissatisfaction. The patients underwent revision surgeries via different techniques and strategies based on previous problems from primary surgery, and postoperative patient satisfaction was high. Complications occurred in 35 patients (10.3%) after revision. CONCLUSIONS: Based on the results of this study, patient dissatisfaction with the procedure can be minimized beforehand through accurate goal identification and careful planning. Bone nonunion is usually due to excessive bone resection during zygoma reduction surgery. Careful selection of the reposition site and appropriate fixation based on a thorough understanding of masseter action are essential in ensuring satisfactory outcomes without adverse side effects. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Innovative Solutions Using Zygoma Implants.

The severely resorbed edentulous maxilla presents significant treatment challenges. The introduction of remote implant support using zygoma implants has provided a plethora of treatment possibilities for many patients. This article presents four very different sets of circumstances successfully treated using this protocol.

[Orbital compartment syndrome. The most frequent cause of blindness following facial trauma]. / Orbitakompartment-szindróma. Arcot ért trauma következtében leggyakrabban vakságot okozó állapot.

INTRODUCTION: Although orbital compartment syndrome is a rare condition, it is still the most common cause of blindness following simple or complicated facial fractures. Its pathomechanism is similar to the compartment syndrome in the limb. Little extra fluid (blood, oedema, brain, foreign body) in a non-space yielding space results with increasingly higher pressures within a short period of time. Unless urgent surgical intervention is performed the blocked circulation of the central retinal artery will result irreversible ophthalmic nerve damage and blindness. Aim, material and method: A retrospective analysis of ten years, 2007-2017, in our hospital among those patients referred to us with facial-head trauma combined with blindness. RESULTS: 571 patients had fractures involving the orbit. 23 patients become blind from different reasons. The most common cause was orbital compartment syndrome in 17 patients; all had retrobulbar haematomas as well. 6 patients with retrobulbar haematoma did not develop compartment syndrome. Compartment syndrome was found among patient with extensive and minimal fractures such as with large and minimal haematomas. Early lateral canthotomy and decompression saved 7 patients from blindness. CONCLUSION: We can not predict and do not know why some patients develop orbital compartment syndrome. Compartment syndrome seems independent from fracture mechanism, comminution, dislocation, amount of orbital bleeding. All patients are in potential risk with midface fractures. We have a high suspicion that orbital compartment syndrome has been somehow missed out in the recommended textbooks of our medical universities and in the postgraduate trainings. Thus compartment syndrome is not recognized. Teaching, training and early surgical decompression is the only solution to save the blind eye. Orv Hetil. 2017; 158(36): 1410-1420.

Bone Resection Versus Setback in Reduction Malarplasty: A Quantitative Analysis of the Migration of the Summit of the Zygoma.

BACKGROUND: We hypothesized that the amount of bone resection and setback together controls the effect of reducing the zygomatic body during reduction malarplasty; however, quantitative analyses of this movement are lacking. METHODS: A retrospective study of patients who underwent reduction malarplasty between Aug. 2013 and Jan. 2015 was performed. We used 3-dimensional computed tomography (3D CT) scanning to measure movements of the summit of the zygoma (SOZ). We analyzed 394 zygomas in 197 patients. RESULTS: The bone resection amount was not significantly correlated with the anteroposterior movement of the SOZ (p = 0.270); in contrast, the setback amount, was significantly correlated with anteroposterior SOZ movement (p < 0.001). The bone resection amount was not correlated with cephalocaudal movement (p = 0.158); however, cephalocaudal movement was significantly correlated with the setback amount (p < 0.001). Both the bone resection amount and the setback amount were correlated with mediolateral movement (p < 0.001). The amount of bone resection determined the mediolateral movement. Both the bone resection amount and the setback amount were correlated with the mean movement distance of the SOZ (p < 0.001). Both the R (2) (0.704 > 0.084) and ß (0.839 > 0.290) values indicated that the setback amount made a larger contribution to the SOZ movement distance than did the bone resection amount. CONCLUSIONS: Whereas bone resection was the major factor in the medial movement of the SOZ, bone setback was the major factor in the anterior and superior movement of the SOZ and a minor factor in the medial movement. The results indicate that both bone reposition and bone resection are important factors in maximizing surgical results of the reduction malarplasty. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

[Zygomatic localization of Langerhans cell histiocytosis - a case report].

Langerhans cell histocytosis is a rare disease. LCH is reported mainly in children aged less than 15 years, however it may appear at any age. In this work, the case of 17-month boy is reported. The boy was admitted to the pediatric ophthalmology department in order to diagnose the swelling and bruising in the lower part of left orbit, which had lasted for one month before. The clinical status, various imaging techniques' results (MRI, TK and PET) and immunohistochemistry led to the final diagnosis of multisystem LCH (spread to masticator muscle and zygomatic bone). After the pharmacological therapy the total remission was achieved. Since four years the child is regularly controlled by oncologists and hematologists with no relapse reported.