Mardini, Samir

Background: Nerve transfer from the masseteric branch of the trigeminal nerve is a widely performed procedure for facial reanimation. Despite achieving powerful muscle force, clinical and aesthetic results leave room for improvement. Preclinical animal models are invaluable to establishing new therapeutic approaches. This anatomical study aimed to establish a masseteric-to-zygomatic nerve transfer model in rats and pigs. Methods: The masseteric branch of the trigeminal nerve and the zygomatic branch of the facial nerve were dissected in 30 swine and 40 rat hemifaces. Both nerves were mobilized and approximated to achieve an overlap between the nerve ends. Over the course of dissecting both nerves, their anatomy, length, and branching pattern were documented. At the coaptation point, diameters of both nerves were measured, and samples were taken for neuromorphometric analysis. Results: Anatomic details and landmarks were described. Tension-free coaptation was possible in all rat and pig dissections. In rats, the masseteric branch had an average diameter of 0.36 mm (±0.06), and the zygomatic branch average diameter was 0.46 mm (±0.13). In pigs, the masseteric branch measured 0.52 (±0.16) mm and the zygomatic branch, 0.59 (±0.16) mm. No significant differences were found between the diameters and axon counts of both nerves in pigs. In rats, however, their diameters, axon counts, and fascicular areas were significantly different. Conclusion: Our study demonstrated the feasibility of direct masseteric-to-zygomatic nerve transfer in rats and pigs and provided general anatomic knowledge of both nerves.

Summary: The latissimus dorsi muscle is the workhorse flap for intrathoracic reconstruction. Prior thoracotomy, which divides the latissimus dorsi muscle, limits the muscle’s intrathoracic reach. We present our experience using the distal portion of the muscle for intrathoracic reconstruction based off an intercostal vessel. We also demonstrate the ability of this intercostal perforator to allow for chimeric flap elevation with a separate skin paddle, depending on the branching pattern of the intercostal vessels. This study provides a case series of three consecutive patients, treated between September 2021 and June 2022. The intrathoracic pathology addressed in these patients are bronchopleural fistula, aortoesophageal fistula, and bronchoesophageal fistula. All patients had the resolution of symptoms related to intrathoracic fistulae and did not experience recurrence. This novel pedicled muscle flap can be an additional option for patients with prior thoracotomy and avoids the morbidity which can be seen with the serratus or rectus abdominis muscle flaps.

Summary: Aging of the face is the result of the interrelation of three-dimensional changes occurring over time among the 5 different layers of the face and its associated structures. Knowledge regarding the causes of these changes and identification of new key anatomic structures have helped elucidate one of the most complex areas of the human body. This has resulted in the introduction of pharmacologic agents to help stop, mitigate, or counteract signs of aging and restore the youthful appearance of the face. The authors performed a systematic search of the literature to review the current highest-level evidence of facial antiaging pharmacologic agents. Pharmacologic and minimally invasive antiaging treatments can target different components of facial aging and continue to evolve. With continuous research efforts, traditional treatments, such as botulinum toxin type A, injectable fillers, and chemical peels, are emerging in newer, more effective formulations, with longer lasting clinical results. However, for soft-tissue descent and facial volume loss, surgery remains the standard treatment. An adequate understanding of the three-dimensional process of facial aging over time (the fourth dimension), facial anatomy, and the pharmacologic properties of antiaging/rejuvenation agents are the sine qua non of facial antiaging treatment. The specific modality should be tailored to patient characteristics, preferences, and goals.

AbstractAdvances in computer-aided design and computer-aided manufacturing software have improved translational applications of virtual surgical planning (VSP) in craniomaxillofacial surgery, allowing for precise and accurate fabrication of cutting guides, stereolithographic models, and custom implants. High-resolution computed tomography (CT) imaging has traditionally been the gold standard imaging modality for VSP in craniomaxillofacial surgery but delivers ionizing radiation. Black bone magnetic resonance imaging (MRI) reduces the risks related to radiation exposure and has comparable functionality when compared with CT for VSP. Our group has studied the accuracy of utilizing black bone MRI in planning and executing several types of craniofacial surgeries, including cranial vault remodeling, maxillary advancement, and mandibular reconstruction using fibular bone. Here, we review clinical applications of black bone MRI pertaining to VSP and three-dimensional (3D)-printed guide creation for craniomaxillofacial surgery. Herein, we review the existing literature and our institutional experience comparing black bone MRI and CT in VSP-generated 3D model creation in cadaveric craniofacial surgeries including cranial vault reconstruction, maxillary advancement, and mandibular reconstruction with fibular free flap. Cadaver studies have demonstrated the ability to perform VSP and execute the procedure based on black bone MRI data and achieve outcomes similar to CT when performed for cranial vault reshaping, maxillary advancement, and mandibular reconstruction with free fibula. Limitations of the technology include increased time and costs of the MRI compared with CT and the possible need for general anesthesia or sedation in the pediatric population. VSP and 3D surgical guide creation can be performed using black bone MRI with comparable accuracy to high-resolution CT scans in a wide variety of craniofacial reconstructions. Successful segmentation, VSP, and 3D printing of accurate guides from black bone MRI demonstrate potential to change the preoperative planning standard of care. Black bone MRI also reduces exposure to ionizing radiation, which is of particular concern for the pediatric population or patients undergoing multiple scans.

Abstract The complex three-dimensional (3D) anatomy in facial allotransplantation creates a unique challenge for surgical reconstruction. Evolution of virtual surgical planning (VSP) through computer-aided design and computer-aided manufacturing has advanced reconstructive outcomes for many craniomaxillofacial indications. Surgeons use VSP, 3D models, and surgical guides to analyze and to trial surgical approaches even prior to entering the operating room. This workflow allows the surgeon to plan osteotomies and to anticipate challenges, which improves surgical precision and accuracy, optimizes outcomes, and should reduce operating room time. We present the development, evolution, and utilization of VSP and 3D-printed guides in facial allotransplantation at our institution, from guide conception to first clinical case.

Abstract Background It is still unclear which facial region contributes most to the perception of an aged face when evaluated by eye-tracking analyses. Objectives The authors sought to apply eye-tracking technology to identify whether mature faces require longer fixation durations than young faces and which facial region contributes most to the perception of a mature face. Methods Eye-tracking analyses were conducted in 74 volunteers (37 males, 37 females; 43 ≤ 40 years, 31 > 40 years) evaluating their gaze pattern and the fixation durations for the entire face and 9 facial subregions. Frontal facial images of 16 younger (<40 years) and older (>40 years) gender-matched individuals were presented in a standardized setting. Results Independent of age or gender of the observer, a younger stimulus image was viewed shorter than an older stimulus image with 0.82 (0.63) seconds vs 1.06 (0.73) seconds with P < 0.001. There was no statistically significant difference in their duration of a stable eye fixation when observers inspected a male vs a female stimulus image [0.94 (0.70) seconds vs 0.94 (0.68) seconds; P = 0.657] independent of the observer’s age or gender. The facial image that captured the most attention of the observer (rank 9) was the perioral region with 1.61 (0.73) seconds for younger observers and 1.57 (0.73) seconds for older observers. Conclusions It was revealed that the perioral region attracts the most attention of observers and contributes most to an aged facial appearance. Practitioners should be mindful of the importance of the perioral region when designing an aesthetic treatment plan.