[Histone acetylation in the development and regeneration of craniofacial hard tissue].

Craniofacial hard tissue mainly includes craniofacial bone and tooth, which is one of the important parts of the mouth-jaw system. Congenital aplasia, tumors and trauma can cause large craniofacial hard tissue defects, which are detrimental to the facial appearance and function of patients, and affect the physical and mental health of patients. Histone acetylation modification is the earliest and most widely studied histone modification, which is an epigenetic modification mechanism jointly regulated by histone acetyltransferase and histone deacetylase. In this paper, we will review the research progress of histone acetylation mediated by histone acetyltransferase and histone deacetylase in the development and regeneration of craniofacial hard tissue.

Modeling stability post zygomatic fracture reconstruction.

Zygomaticomaxillary complex (ZMC) fracture repair is one of the most common surgical procedures performed in craniomaxillofacial trauma management. Miniplates and screws are used to stabilize the fractured bone using small local incisions, however, these procedures are not infrequently associated with hardware-related post-operative complications. The amount of fixation hardware utilized varies depending on the fracture pattern and surgical judgment, with three-point fixation being the conventionally accepted treatment. However, limited experimental testing and clinical studies have suggested that ZMC stabilization may be achieved with less than three-point fixation. In this study, we utilized a previously developed finite element modeling approach that allows for detailed bone and muscle representation to study the mechanical behavior of the fractured craniomaxillofacial skeleton (CMFS) under one, two, or three-point fixation of the ZMC. Results suggest that using a miniplate along the infraorbital rim in three-point fixation increases the amount of strain and load transfer to this region, rather than offloading the bone. Two-point (zygomaticomaxillary and zygomaticofrontal) fixation yielded strain patterns most similar to the intact CMFS. One-point (zygomaticofrontal) fixation resulted in higher tensile and compressive strains in the zygomaticofrontal region and the zygomatic arch, along with a higher tensile strain on the zygomatic body. These modeling results provide biomechanical evidence for the concept of over-engineering in the stabilization of facial fractures. Furthermore, they support previous suggestions that less than three-point fixation of ZMC fractures may be adequate to achieve uneventful healing.

Post-traumatic transocular retained foreign body in the infratemporal fossa: a near miss.

The infratemporal fossa is an uncommon site for lodgement of foreign bodies. Fast-moving projectiles and displaced teeth may get impacted and have been described in the literature. However, foreign body lodgement in the retromaxillary space after transorbital passage is rare. The trajectory of the foreign bodies in such cases is difficult to predict and may not be suspected in the absence of overt clinical features. The authors present a case of a wooden splinter lodged within the infratemporal fossa after the patient sustained a lid injury with an orbital floor fracture. Imaging was equivocal; hence, endoscopic surgical exploration was undertaken, revealing the foreign body. A high index of clinical suspicion and rapid intervention is needed since unsuspected foreign bodies may cause further visual, infective or neurovascular complications. Approaches should be tailored on a case-by-case basis.

The Adelaide Facial Bone Rule: A simple prediction model and clinical guideline for the presence of facial fractures using CT brain scans in victims of minor trauma.

BACKGROUND: Facial fractures bleed, resulting in high-density fluid in the sinuses (haemosinus) on computed tomography (CT) scans. A CT brain scan includes most maxillary sinuses in the scan field, which should allow detection of haemosinus as an indirect indicator of a facial fracture without the need for an additional CT facial bone scan, yet no robust evidence for this exists in the literature. The aim of this study was to determine whether the presence of haemosinus on a CT brain scan, alone or in combination with other clinical information, can predict the presence of facial fractures. METHODS: 1231 adult patients, who had both brain and facial CT scans performed on the same day, were selected from a seven year period. Patients were eligible if scans were requested for trauma. Brain and facial scans were reviewed separately for the presence of facial fractures, haemosinus, emphysema and intra-cranial haemorrhage. Prediction modelling was used to assess whether findings from brain scans could be used to identify patients requiring further CT scanning. FINDINGS: The full prediction model included four predictors and showed excellent discrimination (AUROC 0.982; 95 % CI 0.971 - 0.993). A simplified model, more suitable for clinical implementation, used only facial fractures and haemosinus as predictors. This model showed only marginally poorer discrimination (AUROC 0.964; 95 % CI 0.945 - 0.983) and excellent performance on other measures. CONCLUSION: Based on the excellent performance of the simplified prediction model, we present the Adelaide Facial Bone Rule: The absence of blood in the sinuses or facial fractures on a CT brain scan means a CT facial bone scan does not need to be routinely performed in the setting of clinically-determined minor trauma.

The accuracy and reliability of different midsagittal planes in the symmetry assessment using cone-beam computed tomography.

Symmetry is an essential component of esthetic assessment. Accurate assessment of facial symmetry is critical to the treatment plan of orthognathic surgery and orthodontic treatment. However, there is no internationally accepted midsagittal plane (MSP) for orthodontists and orthognathic surgeons. The purpose of this study was to explore a clinically friendly MSP, which is more accurate and reliable than what is commonly used in symmetry assessment. Forty patients with symmetric craniofacial structures were analyzed on cone-beam computed tomography (CBCT) scans. The CBCT data were exported to the Simplant Pro software to build four reference planes that were constructed by nasion (N), basion (Ba), sella (S), odontoid (Dent), or incisive foramen (IF). A total of 31 landmarks were located to determine which reference plane is the most optimal MSP by comparing the asymmetry index (AI). The mean value of AI showed a significant difference (p < 0.05) among four reference planes. Also, the mean value of AI for all landmarks showed that Plane 2 (consisting of N, Ba, and IF) and Plane 4 (consisting of N, IF, and Dent) were more accurate and stable. In conclusion, the MSP consisting of N, Dent, and IF shows more accuracy and reliability than the other planes. Further, it is more clinically friendly because of its significant advantage in landmarking.

Development of AI-Based Diagnostic Algorithm for Nasal Bone Fracture Using Deep Learning.

Facial bone fractures are relatively common, with the nasal bone the most frequently fractured facial bone. Computed tomography is the gold standard for diagnosing such fractures. Most nasal bone fractures can be treated using a closed reduction. However, delayed diagnosis may cause nasal deformity or other complications that are difficult and expensive to treat. In this study, the authors developed an algorithm for diagnosing nasal fractures by learning computed tomography images of facial bones with artificial intelligence through deep learning. A significant concordance with human doctors' reading results of 100% sensitivity and 77% specificity was achieved. Herein, the authors report the results of a pilot study on the first stage of developing an algorithm for analyzing fractures in the facial bone.

Facial Anthropometric Analysis of Gender-Related Characteristics in Computed Tomography.

BACKGROUND: In recent years, facial feminization surgery (FFS) has gained increasing popularity because of increases in transgender individuals and the acceptance of diversity in gender identity. However, there is still a scarcity of anthropometric research to guide evidence-based practices for FFS in Taiwan. AIM AND OBJECTIVES: The purpose of this study was to provide a reference for surgeons to achieve optimal outcomes for patients undergoing FFS. The anthropometric analysis could help surgeons meet patients' specific requirements and improve patients' alignment with their gender identity. MATERIALS AND METHODS: The study group consisted of 100 patients (50 males and 50 females) who had undergone cranial computed tomography at Chang Gung Memorial Hospital in Taiwan because of the indication of blunt injuries to the head and face with suspected skull and facial fractures. The computed tomography images were imported into the OsiriX image software to conduct an anthropometric evaluation. The parameters used in the measurements included 2 aspects: bone and soft tissue anthropometric analysis. RESULTS: Anthropometric data were obtained from 50 males (age 32.6 ± 11.4 years) and 50 females (age 33.7 ± 10.3 years). The results for bone measurements showed that both the forehead bossing length and nasal bone width in the male group were significantly greater. The frontal angle in both bone and soft tissue in the male group was significantly smaller. The chin height and bigonial width in both bone and soft tissue in the male group were significantly greater. Although the average gonial angle was greater in the female group, the difference was not significant. For the measurements of lip projection, the results showed that there was no significant difference. Although this group of Asian males had more acute nasolabial angles, the difference was not statistically significant. However, the average nasofrontal angle among females was significantly more obtuse than among males. CONCLUSION: The results revealed that Asian males tend to have more prominent superior orbital rims, wider nasal bones, and wider and taller mandibles compared with Asian females. Despite showing some trends, the gonial angle and lip projections did not reveal any significant differences, which is likely because of a large amount of variation.

Successful Reduction of Unilateral Zygoma Fracture Following Bilateral Malar Reduction Surgery.

Malar reduction surgery can increase its susceptibility to fractures in case of trauma. Patients who had malar reduction surgery and sustained a zygoma fracture pose unique challenges for treatment and management. This is a case of a 28-year-old female patient who presented with a unilateral zygoma fracture following bilateral malar reduction and augmentation rhinoplasty 6 years ago. Physical examination revealed a clicking sound when opening the mouth at the right zygomatic buttress and a depressed preauricular area, suggesting arch fracture. Computed tomography imaging demonstrated a loosened screw at the right zygomatic buttress and a depressed arch fracture. She wanted to remove all plates and treat her right fractured zygoma with absorbable materials. Through the bilateral intraoral incisions, the authors removed the plates and screws and reduced the depression with the Langenbeck elevator through the same right intraoral incision without fixation. The reduction was well-maintained without complications based on postoperative plain x-rays 1 month after surgery. She reported that the pain was mostly gone and that she did not hear any abnormal sounds when opening her mouth after the surgery. In this case, if the zygomaticomaxillary buttress is minimally displaced, but the zygomatic arch fracture is significantly depressed, the authors believe that fracture reduction with only an intraoral incision would be enough to achieve an optimal outcome. If the plates and screws used in the previous malar reduction are not well maintained, it may be necessary to remove them.

Microvascular Free Flap Outcomes in Maxillectomy Defects from Invasive Fungal Sinusitis.

OBJECTIVES: Microvascular free tissue transfer is routinely used for reconstructing midface defects in patients with malignancy, however, studies regarding reconstructive outcomes in invasive fungal sinusitis (IFS) are lacking. We aim to describe outcomes of free flap reconstruction for IFS defects, determine the optimal time to perform reconstruction, and if anti-fungal medications or other risk factors of an immunocompromised patient population affect reconstructive outcomes. METHODS: Retrospective review of reconstruction for IFS (2010-2022). Age, BMI, hemoglobin A1c, number of surgical debridements, and interval from the last debridement to reconstruction were compared between patients with delayed wound healing versus those without. Predictor variables for delayed wound healing and the effect of time on free flap reconstruction were analyzed. RESULTS: Twenty-seven patients underwent free flap reconstruction for IFS. Three patients were immunocompromised from leukemia and 21 had diabetes mellitus (DM). Patients underwent an average of four surgical debridements for treatment of IFS. The interval from the last IFS debridement to flap reconstruction was 5.58 months (±5.5). Seven flaps (25.9%) had delayed wound healing. A shorter interval of less than 2 months between the last debridement for IFS and reconstructive free flap procedure was associated with delayed wound healing (Fisher Exact Test p = 0.0062). Other factors including DM, BMI, HgA1c, and bone reconstruction were not associated with delayed wound healing. CONCLUSION: Patients with maxillectomy defects from IFS can undergo microvascular-free flap reconstruction with good outcomes while on anti-fungal medication. Early reconstruction in the first 2 months after the last IFS debridement is associated with delayed wound healing. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:1642-1647, 2024.

Biparietal remodelling and total vault remodelling in scaphocephaly-a comparative study using 3d stereophotogrammetry.

PURPOSE: The aim of the study was to compare the results of two surgical techniques for the treatment of isolated sagittal synostosis (ISS) by means of 3D stereophotogrammetry. One technique, the Renier's "H" technique (RHT) comprised a biparietal expansion, the other, the total vault remodeling (TVR) included also a frontal remodeling. METHODS: The two groups of operated children were compared with a third control group of normocephalic children. The 3D scanning was performed in all children between 12 and 245 months of age. On each 3D image six measurements and indices have been made, with the aim of evaluating not only length and width of the head, but also the height. The cranial index (CI) was measured in a plane parallel to the nasion-tragus plane, at the intersection with the opisthocranion. RESULTS: Each of the three groups (RHT, TVR, control group) included 28 children. The measurements that were influenced by the correction of the frontal bossing, namely the CI and the sagittal length, were closer to normocephaly after TVR than after RHT. Lesser or no statistical difference was documented in the measurements evaluating the biparietal aspect and the height of the vertex, indicating that the biparietal expansion is effective in both procedures. CONCLUSION: Based on our results TVR results in a better esthetical outcome, particularly in relation to the direct surgical remodeling of the frontal bossing.

Risk of complications in panfacial bone fracture according to surgeons: A meta-analysis.

BACKGROUND: Panfacial bone fractures pose intricate challenges because of severe fragmentation and the loss of landmarks. Surgeons use a variety of reduction techniques, including bottom-up and top-down approaches. This single proportional meta-analysis explores sequencing differences and complications between oral and maxillofacial surgery surgeons (OMSs) and plastic and reconstructive surgeons (PRSs) in treating panfacial bone fractures. METHODS: The PubMed and Scopus databases were searched systematically, and we compiled 14 studies published between 2007 and 2023 involving 1238 patients. A systematic review of the included studies was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, and data on the reduction techniques; total complication rates; and rates of malocclusion, enophthalmos, infection, asymmetry, and esthetic complications were collected. RESULTS: The bottom-up technique was the most prevalent for both types of surgeons (57.1%, 8 out of 14). Malocclusion rates (I2 = 0% for OMSs and 41% for PRSs) were similar between the groups (p = 0.72), but PRSs tended to have a lower enophthalmos rate (I2 = 0% for OMSs and 32% for PRSs) than OMSs (p < 0.01). Infection rates remained consistent across all studies. However, high heterogeneity was observed for the total complication rate (I2 = 94% for OMSs and 85% for PRSs) and asymmetry and esthetic complications (I2 = 88% for OMSs and 92% for PRSs), making direct comparison between the two groups inconclusive. CONCLUSIONS: In this study, the differences in surgical techniques and levels of interest have a greater impact on the outcomes of the panfacial bone fracture than the surgeon's specialty. However, more in-depth studies are needed to accurately pinpoint panfacial bone fracture reduction trends and differences in postoperative complications in the two expert groups.

Serial assessment and long-term radiographic evaluation of the maxillary sinus after inferior maxillectomy and soft tissue free flap reconstruction in patients with oral cancer.

PURPOSE: This study evaluates serial radiographic changes in the maxillary sinus of patients with oral cancer after an inferior maxillectomy and a soft tissue free flap reconstruction. METHODS: Fifty-six patients were evaluated between Oct 2005 and Mar 2017 from an institutional database. Preoperative and surveillance imaging was reviewed at set time-points. Maxillary sinus scores were allotted based on a modification of the Lund-MacKay staging system. Patients were evaluated for change in sinus score. A univariate (UV) and multivariate (MV) analysis was performed. RESULTS: There were 53.5% T3/T4 category tumors and 68% received adjuvant treatment. Median follow-up was 24.4 months. Preoperative mean sinus score was 0.27 ± 0.44 and postoperative mean sinus score at 24 months was 1.2 ± 1.3 (p = <0.001). On UV analysis advanced T-stage at 12 months (OR 6.7, 95% CI 1.2-50.3, p = 0.01) and 24 months (OR 5.2, 95% CI 1.03-36.8, p = 0.04) was associated with significantly higher sinus score. On MV analysis, advanced T-stage continued to be associated with increased odds for higher sinus score (OR 4.9, 95% CI 1.1-26.8, p = 0.039). CONCLUSION: A mild increase in postoperative sinus score is seen in this cohort of patients. Advanced T-stage is associated with increased odds for higher sinus scores.

The pattern of maxillofacial fractures associated with rollover accidents: A 7-year retrospective study.

BACKGROUND/AIM: This study aimed to assess the incidence and pattern of maxillofacial fractures and related demographic data in the victims of rollover crashes. PATIENTS AND METHODS: This retrospective study was based on medical records of patients who sustained maxillofacial injuries following rollover accidents. Investigated data included age, gender, accident date and time, accident cause, seat belt usage, airbag deployment, road type, anatomical location of the facial fracture, and treatment approach. RESULTS: Among the 147 patients who met the inclusion criteria, the most prevalent age groups were 20-30 (36.7%) and 30-40 (32.7%) years, with a mean age of 33.6 ± 9.7 years. The male-to-female ratio was 6:1. Most crashes occurred in March, August, and July. These accidents involved 69.4% light vehicles and 39.6% heavy vehicles. The leading causes of rollover crashes were speeding (58.5%) followed by distracted driving (21.1%) and traffic rule violations (13.6%). The most prevalent injuries were fractures of the maxillary sinus wall (40.8%), nasal bones (39.5%), zygomaticomaxillary complex (36.1%), and the mandible (32.6%). Surgical intervention was necessary for 44.2% of patients, while 12.9% of cases underwent close reduction, and 42.9% did not require any surgical intervention. The occurrence of nasal bone fractures was significantly lower in cases where seat belts were worn and zygomatic arch fractures were less frequent in incidents with airbag deployment. CONCLUSIONS: In rollover crashes, the midface is the most vulnerable anatomical location. Utilization of seat belts and airbag deployment has the potential to prevent nasal bone and zygomatic arch fractures.

LeFort III Versus Monobloc Frontofacial Advancement: A Comparative Analysis of Soft Tissue Changes.

INTRODUCTION: The LeFort III and monobloc are commonly used midface advancement procedures for patients with syndromic craniosynostosis with well characterized postoperative skeletal changes. However, the differential effects of these procedures on facial soft tissues are less understood. The purpose of this study was to critically analyze and compare the effects of these 2 procedures on the overlying soft tissues of the face. METHODS: Frontal and lateral preoperative and postoperative photographs of patients undergoing monobloc or LeFort III were retrospectively analyzed using ImageJ to measure soft tissue landmarks. Measurements included height of facial thirds, nasal length and width, intercanthal distance, and palpebral fissure height and width. Facial convexity was quantified by calculating the angle between sellion (radix), subnasale, and pogonion on lateral photographs. RESULTS: Twenty-five patients with an average age of 6.7 years (range 4.8-14.5) undergoing monobloc (n=12) and LeFort III (n=13) were identified retrospectively and analyzed preoperatively and 6.4±3.6 months postoperatively. Patients undergoing LeFort III had a greater average postoperative increase in facial convexity angle acuity (28.2°) than patients undergoing monobloc (17.8°, P =0.021). Patients in both groups experience postoperative increases in nasal width ( P <0.001) and decreases in palpebral fissure height ( P <0.001). CONCLUSIONS: Both subcranial LeFort III advancements and monobloc frontofacial advancements resulted in significant changes in the soft tissues. Patients undergoing LeFort III procedures achieved greater acuity of the facial convexity angle, likely because the nasion is not advanced with the LeFort III segment.

A Method for Precise Reduction of Facial Bone Fractures Using Intraoperative Ultrasound With a Solid Gel Pad as a Coupling Medium.

This study introduces a method to overcome technical challenges in using intraoperative ultrasound for the closed reduction of nasal bone and zygomatic arch fractures. The curvature of the face makes it difficult to apply an ultrasound probe to the facial area. We used a solid gel pad as a coupling medium during surgery to improve the scanning of facial bone fractures. The results show that the fracture sites observed on preoperative computed tomography scans can be easily visualized using intraoperative ultrasound, and real-time manipulation confirms successful reduction. The solid gel pad is light, malleable, easy to use, and provides accurate images. Overall, the use of ultrasound with a solid gel pad enhances the accuracy of closed reduction in facial bone fracture surgeries, confirming fracture patterns and ensuring precise reduction.

The Use of Dynamic Navigation Systems as a Component of Digital Dentistry.

The development of dynamic navigation system (DNS) has facilitated the development of modern digital medicine. In the field of dentistry, the cutting-edge technology is garnering widespread recognition. Based on the principles of 3-dimensional visualization, virtual design, and precise motion tracking, DNS is mainly composed of a computer, a tracking system, specialized tracer instruments, and navigation software. DNS employs a workflow that begins with preoperative data acquisition and imaging data reconstruction, followed by surgical instrument calibration and spatial registration, culminating in real-time guided operations. Currently, the system has been applied in a broad spectrum of dental procedures, encompassing dental implants, oral and maxillofacial surgery (such as tooth extraction, the treatment of maxillofacial fractures, tumors, and foreign bodies, orthognathic surgery, and temporomandibular joint ankylosis surgery), intraosseous anesthesia, and endodontic treatment (including root canal therapy and endodontic surgery). These applications benefit from its enhancements in direct visualization, treatment precision, efficiency, safety, and procedural adaptability. However, the adoption of DNS is not without substantial upfront costs, required comprehensive training, additional preparatory time, and increased radiation exposure. Despite challenges, the ongoing advancements in DNS are poised to broaden its utility and substantially strengthen digital dentistry.