Effects of exposure length, cortical and trabecular bone contact areas on primary stability of infrazygomatic crest mini-screws at different insertion angles.

BACKGROUND: The infrazygomatic crest mini-screw has been widely used, but the biomechanical performance of mini-screws at different insertion angles is still uncertain. The aim of this study was to analyse the primary stability of infrazygomatic crest mini-screws at different angles and to explore the effects of the exposure length (EL), screw-cortical bone contact area (SCA), and screw-trabecular bone contact area (STA) on this primary stability. METHODS: Ninety synthetic bones were assigned to nine groups to insert mini-screws at the cross-combined angles in the occlusogingival and mesiodistal directions. SCA, STA, EL, and lateral pull-out strength (LPS) were measured, and their relationships were analysed. Twelve mini-screws were then inserted at the optimal and poor angulations into the maxillae from six fresh cadaver heads, and the same biomechanical metrics were measured for validation. RESULTS: In the synthetic-bone test, the LPS, SCA, STA, and EL had significant correlations with the angle in the occlusogingival direction (rLPS = 0.886, rSCA = -0.946, rSTA = 0.911, and rEL= -0.731; all P < 0.001). In the cadaver-validation test, significant differences were noted in the LPS (P = 0.011), SCA (P = 0.020), STA (P = 0.004), and EL (P = 0.001) between the poor and optimal angulations in the occlusogingival direction. The STA had positive correlations with LPS (rs = 0.245 [synthetic-bone test] and r = 0.720 [cadaver-validation test]; both P < 0.05). CONCLUSIONS: The primary stability of the infrazygomatic crest mini-screw was correlated with occlusogingival angulations. The STA significantly affected the primary stability of the infrazygomatic crest mini-screw, but the SCA and EL did not.

In-house protocol for fully guided zygomatic implant surgery and prosthesis repositioning. A technical note

AIM: The present study aims to describe an in-house protocol for fully guided zygomatic implant surgery and prosthesis repositioning. MATERIALS AND METHODS: Four extramaxillary zygomatic dental implants (ZIs) were placed in one patient. The preoperative phase included digital planning, through which a surgical guide was designed and created. The analysis of the accuracy of guided surgery and the guided prosthesis repositioning was carried out by superimposing the digital planning with the final postsurgical implant positioning through CBCT. The radiologic evaluation included implant angular deviation, entrance and exit deviation, platform deviation, and apex apicocoronal and mesiodistal deviation. The prosthetic evaluation was performed in three directions: buccopalatal, apicocoronal, and mesiodistal. RESULTS: All the ZIs successfully osseointegrated after 3 months of healing, with no complications. The mean axial angular implant deviation was 0.52 ± 0.36 degrees, and the mean implant depth deviation was 0.47 ± 0.28 mm. The entrance and exit deviation of the implants was 0.74 ± 0.42 mm and 0.7 ± 0.43 mm, respectively. The virtual prosthesis was superimposed and compared with the standard tessellation language file of the provisional polymethyl methacrylate prosthesis at the level of the first molars and central incisors; the mean buccopalatal deviation was 0.6 ± 0.035 mm, the mean apicocoronal deviation was 0.65 ± 0.11 mm, and the mean mesiodistal deviation was 0.3 ± 0.07 mm. CONCLUSIONS: According to the results obtained in this first case of the present case series, careful and meticulous digital planning based on the correct prosthetic parameters can safely guide the performance of surgery.

Modified Orbitozygomatic Craniotomy Approach for a Recurrent Orbital Tumor in a Pediatric Patient.

Background: This report aims to present the case of a pediatric patient with a recurrent tumor in the superolateral orbit. Clinical Presentation: An 8-year-old patient was initially treated for a tumor in the superolateral orbit via a transconjunctival approach. The histopathological diagnosis was epidermoid cyst. Postoperatively, chronic inflammation and fistula developed in the lateral canthus area. Magnetic resonance imaging revealed a residual tumor posterior to the original tumor location. The patient was treated via a modified orbitozygomatic (mOZ) craniotomy approach that was originally applied in neurosurgery, and complete tumor removal was achieved. A temporary paralysis of the frontotemporal branch of the facial nerve was observed and fully resolved within one month following surgery. At the 18th month of follow-up, the visual, neurological, and cosmetic results were found to be satisfactory. Conclusions: mOZ craniotomy can be used to access and operate on recurrent orbital tumors in pediatric patients where other more aggressive surgical approaches should be avoided.

[Clincopathological analysis of 171 patients with osteochondroma and malignant transformation in maxillofacial bone].

PURPOSE: To investigate the clinical and pathological features of osteochondroma in maxillofacial region, and to summarize the clinicopathological features of rare osteochondroma malignant transformation in order to provide clinical guidance. METHODS: From January 2018 to September 2023, a total of 171 patients with osteochondroma were retrospectively collected in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. Their preoperative CT and clinicopathological features were analyzed. RESULTS: Of the 171 patients with osteochondroma in maxillofacial bone, 66%（113/171） were females and 34% were male. Their age ranged from 11-76 with an average age was 44 years old. Of the 171 cases, 95.3%（163/171）in mandible condyle, 4%(7/171) in mandible processus coronoideus, and 0.5%（1/171） in zygomatic arch. The imaging findings showed that the thickness of cartilaginous cap was less than 1 cm in 98%（159/161） cases with condyle lesions. Only 2 cases(2/171, 1.1%) had malignant transformation. One was diagnosed with secondary chondrosarcoma, another developed low-grade osteosarcoma. CONCLUSIONS: Osteochondroma in maxillofacial region mostly occurs in females, and most commonly located in condylar process, with a malignant change rate of 1.1%, which is similar to that of other parts of the body. Imaging findings have important guiding significance for the diagnosis of osteochondroma malignant change.

Prevalence of Zygomatic Air Cell defects in a sample of 6-18-year-old patients in Saudi Arabia and Yemen: a retrospective study.

OBJECTIVES: This study aimed to comprehensively analyze the prevalence and influencing factors of Zygomatic Air Cell Defects (ZACD) among pediatric and adolescent populations in Saudi Arabia and Yemen. MATERIALS AND METHODS: A cross-sectional retrospective study was conducted, utilizing digital panoramic radiographs of dental outpatients aged 6 to 18 years. The data were collected from registered digital databases of dental clinics in Al-Qassim, Saudi Arabia, and an oral and maxillofacial radiology center in Sana'a, Yemen, covering the period from July 2018 to September 2022. The radiographs were evaluated based on inclusion and exclusion criteria, and ZACD was assessed using standardized descriptions. Statistical analysis, including logistic regression, was employed to examine the impact of the associated factors. RESULTS: The study encompassed a total of 3,169 participants, revealing an overall ZACD prevalence of 28.5%. Age emerged as a significant predictor (p ≤ 0.0001), with the likelihood of ZACD increasing as the age of the individual advances. Gender and geographic region did not exhibit statistically significant differences in ZACD prevalence. CONCLUSION: This study provides crucial insights into the prevalence of Zygomatic Air Cell Defects among pediatric and adolescent populations in Saudi Arabia and Yemen. It underscores the prevalence of ZACD and the notable influence of age on its occurrence. Additionally, the research challenges prior notions of gender and regional variations in ZACD prevalence, emphasizing the complexity of the factors involved. Early detection is essential to avoid unwanted complications during any surgical intervention in this area.

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

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

Temporary Anchorage Device Misplaced into Infratemporal Space - A Case Report.

INTRODUCTION: During orthodontic treatment, temporary anchoring devices (TADs) are used to restrain tooth movement. They are a relatively recent addition to the dental toolkit. AIM: As TADs have limitations, Dr. Eric Lieu of Taiwan developed Infra Zygomatic Crest (IZC) screws which are placed between the maxillary second premolar at the bony crest. TREATMENT PLANNING: The goal of this case study is to emphasize the value of anatomy, site selection, and IZC retrieval in the event of an accident. Cone beam computed tomography was used as a diagnostic tool for the precise location of the displaced IZC and immediate surgical retrieval was done under local anesthesia from the infratemporal space to prevent further complications. TAKEAWAY LESSONS: Orthodontists knowledge of soft tissue and hard tissue anatomy and precise positioning is crucial for successful TAD implantation.

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

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

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

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

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

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

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

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

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

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

A case series on a new reference in mandibular angles harmonization: the Frontozygomatic-Infraorbital Line (FZ-IOL).

the aim of this paper, is to propose a new reference line: the Frontozygomatic-Infraorbital Line (FZ-IOL). This reference line can guide the surgical team planning mandibular angle harmonization, based on the patient's skeletal proportion. The Frontozygomatic-Infraorbital Line has been adopted for symmetrization surgery, masculinization surgery, and in unsatisfactory results of previous orthognathic surgery. From March 2021 to December 2022, 3 patients were treated for severe facial asymmetry affecting mainly the lower third of the face. All cases were planned with the reference FZ-IOL. Patients were treated in the same center, at the Orthognathic Surgery Department of the Instituto Portugues da Face, Lisbon, Portugal. The Frontozygomatic-Infraorbital Line is designed virtually using software to reconstruct a 3D image from a digital imaging and communications in medicine (DICOM) file obtained from a cone beam computer tomography (CBCT). , connecting the two orbital rims. Then, a vertical line, the frontozygomatic line perpendicular to the IOL and passing through the outmost lateral portion of the frontozygomatic suture is drawn. The proposed line demonstrated how establishing appropriate reference lines is crucial for the success of the surgery. The selection of reference lines should be based on the patient's anatomy, the symmetrization process's complexity, and the surgery's desired outcome. The Frontozygomatic-Infraorbital Line represents an adequate reference line for managing mandibular angle lateral projection, improving lower third of the face symmetrization.

Corrección de la atresia maxilar y del plano oclusal utilizando MARPE y mini-implantes extra-alveolares / Correction of maxillary atresia and occlusal plane using MARPE and extra-alveolar mini-implants

Para el tratamiento no quirúrgico de la atresia maxilar en pacientes con osificación avanzada de la sutura palatina media, existe la alternativa de un disyuntor anclado en mini-implantes. El éxito no está garantizado, pero se puede hacer este intento antes de realizar una expansión asistida quirúrgicamente. Del mismo modo, el uso de mini-implantes extra-alveolares para el movimiento de grupos dentales en la corrección de maloclusiones es algo cada vez más aplicado debido a una mejor accesibilidad. El objetivo de este estudio es presentar el caso de un paciente adulto joven con atresia maxilar tratado con MARPE y la corrección del plano oclusal mediante mini-implantes extra-alveolares. Clínicamente se observó la apertura de la sutura media palatina; radiográficamente, la ligera rotación de la mandíbula en sentido antihorario, la mejora de la inclinación del plano oclusal, la disminución de la inclinación y protrusión de los incisivos superiores e inferiores, y la distalización de los molares mandibulares, estableciendo una relación molar en Clase I. La expansión con MARPE en el caso de este paciente adulto joven con atresia maxilar fue efectiva. Se consiguió la corrección del plano oclusal con el uso de mini-implantes extra-alveolares, así como resultados estéticos y funcionales muy satisfactorios. Entre varias alternativas de tratamiento, la técnica a realizar dependerá de factores como la efiencia, la conservación de los elementos dentales, la colaboración del paciente y la estabilidad.

For the non-surgical treatment of maxillary atresia in patients with an advanced degree of ossification of the midpalatal suture, there is an alternative of an expander anchored in miniscrews. Success is not guaranteed, but this attempt can be made before recommending surgically assisted expansion. Similarly, the use of extra-alveolar miniscrews for dental movement in the correction of malocclusions is something that is increasingly being applied due to better accessibility. The aim of this work is to present the case of a young adult patient with maxillary atresia treated with MARPE and the correction of the occlusal plane through the use of extra-alveolar miniscrews. Clinically, the opening of the midpalatal suture was observed, radiographically, the slight rotation of the mandible in an anti-clockwise direction, the improvement in the inclination of the occlusal plane, the decrease in the inclination and protrusion of the upper and lower incisors, and the distalization of the lower molars establishing a Class I molar relationship. The expansion with MARPE in the case of a young adult patient with maxillary atresia was effective. The correction of the occlusal plane with the use of extraalveolar miniscrews was achieved, as well as very satisfactory aesthetic and functional results. Among various treatment alternatives, the technique to be executed will depend on factors such as efficiency, conservation of dental elements, patient collaboration, and stability.

Image fusion-based low-dose CBCT enhancement method for visualizing miniscrew insertion in the infrazygomatic crest.

Digital dental technology covers oral cone-beam computed tomography (CBCT) image processing and low-dose CBCT dental applications. A low-dose CBCT image enhancement method based on image fusion is proposed to address the need for subzygomatic small screw insertion. Specifically, firstly, a sharpening correction module is proposed, where the CBCT image is sharpened to compensate for the loss of details in the underexposed/over-exposed region. Secondly, a visibility restoration module based on type II fuzzy sets is designed, and a contrast enhancement module using curve transformation is designed. In addition to this, we propose a perceptual fusion module that fuses visibility and contrast of oral CBCT images. As a result, the problems of overexposure/underexposure, low visibility, and low contrast that occur in oral CBCT images can be effectively addressed with consistent interpretability. The proposed algorithm was analyzed in comparison experiments with a variety of algorithms, as well as ablation experiments. After analysis, compared with advanced enhancement algorithms, this algorithm achieved excellent results in low-dose CBCT enhancement and effective observation of subzygomatic small screw implantation. Compared with the best performing method, the evaluation metric is 0.07-2 higher on both datasets. The project can be found at: https://github.com/sunpeipei2024/low-dose-CBCT .

[Anatomical Identification and Possibilities of Transfer of the Masseteric Nerve for Facial Reanimation]. / Anatomische Auffindbarkeit und Möglichkeiten des Transfers des Nervus massetericus zur Gesichtsreanimation.

BACKGROUND: The masseteric nerve (MN) is often used as a donor nerve for facial reanimation. In addition to already established techniques, MN transfer is rapidly gaining importance, mainly due to the single-stage approach of the procedure and its reconstructive potential. This anatomical study and the associated questionnaire study aimed to evaluate the established methods for identification of the MN and its suitability for direct nerve transfer as well as to assess the importance of MN transfer in the daily clinical routine. MATERIAL AND METHODOLOGY: Bilateral dissection of 25 fresh-frozen head specimens (n=50; 13 female, 12 male) was performed with accompanying measurement of the MN. In a questionnaire study conducted at established centres for facial surgery in German-speaking countries, clinical experience data of MN transfer was collected using the SurveyMonkey software. The data obtained was statistically analysed using Microsoft Excel and presented in numerical tables and boxplots. RESULTS: Using anatomical landmarks such as the zygomatic arch and the mandibular notch for orientation, the MN was found in 100% of cases. Its average length from the emerging point below the zygomatic arch towards its entry into the masseter muscle was measured to be 22 mm and was the length available for nerve transposition. Tension-free coaptation of the MN with the zygomatic branch was possible in 94% of cases. The questionnaire showed that the MN is considered an important donor nerve for motor nerve transfers and that MN transfer is now largely established as a standard procedure. DISCUSSION: In accordance with previously published studies, the MN was reliably found at the height of the mandibular notch and, in the vast majority of cases, was suitable for tension-free coaptation with the zygomatic branch. Differences to the existing literature, however, can be seen in the length of the nerve available for nerve transposition and the frequency of its division into several branches before entering the masseter muscle. In German-speaking countries, Cross-Face Nerve Grafting (CFNG) is still the preferred method for facial reanimation surgery. However, MN transfer is also well established by now, both as an alternative and a supplement to other techniques, possibly due to its low donor site morbidity and short time to regeneration.

Transmalar Kirshner Wire Fixation Under Ultrasound Scanning is Useful for Unstable Zygomatic Arch Fracture Combined With Zygomatic Body Fracture.

Plate fixation to zygomatic arch fractures carries the risk of facial nerve palsy and scarring of the cheek; however, without plate fixation, bone deviation or displacement may reoccur after surgery. Furthermore, zygomatic arch fractures combined with zygomatic body fractures are more postoperatively unstable than single zygomatic arch fractures. Few reports have focused on this combined fracture type, and no consensus has been reached regarding treatment. Because plate fixation for slight deviation of the zygomatic body has little advantage for stabilization, the authors, usually opt for transmalar pinning alone instead of plate fixation at the hospital. This study is a retrospective case series of 7 patients, among 100 zygomatic fractures excluding isolated zygomatic arch fractures, treated using transmalar pinning under ultrasound scanning. The reduction was performed through the oral and temporal incision as a surgical procedure. Under ultrasound observation, a Kirshner wire was inserted into the zygomatic body from the unaffected side while maintaining the reduced position. The wire was removed at an outpatient visit 2 to 3 months following surgery. In all cases, the zygomatic body was of the laterally rotated type, and postoperative morphologic evaluation showed improvement without postoperative complications. Scores were higher in middle-aged and older than in young people. Correction of zygomatic rotation also scored higher than zygomatic arch morphology. Transmalar Kirshner wire fixation under ultrasound observation is a simple and minimally invasive method for zygomatic arch fractures, which avoids the possible complications related to plate fixation.

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

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