A Cadaveric Study of the Communication Patterns Between the Buccal Trunks of the Facial Nerve and the Infraorbital Nerve in the Midface.

Most nerve communications reported in the literature were found between the terminal branches. This study aimed to clarify and classify patterns of proximal communications between the buccal branches (BN) of the facial nerve and the infraorbital nerve (ION).The superficial musculoaponeurotic system protects any communication sites from conventional dissections. Based on this limitation, the soft tissues of each face were peeled off the facial skull and the facial turn-down flap specimens were dissected from the periosteal view. Dissection was performed in 40 hemifaces to classify the communications in the sublevator space. Communication site was measured from the ala of nose.A double communication was the most common type found in 62.5% of hemifaces. Triple and single communications existed in 25% and 10% of 40 hemiface specimens, respectively. One hemiface had no communication. The most common type of communication occurred between the lower trunk of the BN of the facial nerve and the lateral labial (fourth) branch of the ION (70% in 40 hemifaces). Communication site was deep to the levator labii superioris muscle at 16.2 mm from the nasal ala. Communications between the motor and the sensory nerves in the midface may be important to increase nerve endurance and to compensate functional loss from injury.Proximal communications between the main trunks of the facial nerve and the ION in the midface exist in every face. This implies some specific functions in normal individuals. Awareness of these nerves is essential in surgical procedure in the midface.

Anatomical and ultrasound-based injections for sunken upper eyelid correction.

BACKGROUND: A needle or a cannula can be safely used during filler injection procedures to correct a sunken upper eyelid. To date, there are no precise injection points recommended that are based on an anatomical study. OBJECTIVE: This study systematically investigated the vascular pattern and depth of forehead arteries at the periorbital area of upper eyelid. METHODS: Twenty cadavers were dissected in this study. Additional data were obtained from 30 healthy volunteers using Doppler ultrasound imaging with high-frequency probe. RESULTS: The ophthalmic artery divided into two opposite primary branches: the superior and inferior orbitoglabellar arteries running along the orbital rim. After the supratrochlear artery arose from the superior orbitoglabellar artery at the medial eyebrow, the supraorbital artery either divided from this artery near the supraorbital foramen or emerged as an individual artery from the supraorbital notch. The inferior orbitoglabellar artery gave off the radix artery superior to the medial canthal tendon. The radix artery divided into two opposite branches: the dorsal nasal artery going to the nose and the paracentral artery going to the glabella. Ultrasound imaging revealed a subcorrugator space that a cannula can safely pass through. At the supraorbital foramen/notch, the supraorbital artery traveled very close to the bone. Based on the anatomical data collected, the following injection points for a needle and a cannula technique are recommended. CONCLUSION: Correction of a sunken upper eyelid is a dangerous procedure which should be performed only by experienced physicians. However, with precise anatomical knowledge and correct techniques, optimal outcomes can be safely achieved.

Investigation of the presence and variation of the ascending mental artery: Conventional dissections and ultrasonographic study.

BACKGROUND: Tongue and mouth floor infarction following filler injections for chin augmentation is a rare complication that has the increase in incidence been reported. OBJECTIVE: This study investigated the arterial anastomosis between the submental and sublingual arteries that can lead to the emboli and subsequent tongue infarction during chin augmentation. METHODS: Forty-two formaldehyde-embalmed cadavers and four soft-embalmed cadavers were dissected to verify the incidence and source of the ascending mental artery. Ultrasonographic study of the artery was performed in 10 healthy volunteers. Attention was paid to discriminate whether the ascending mental artery arose from the submental artery or the sublingual artery using the arch of the mylohyoid muscle as the discriminating landmark. RESULTS: Incidence of ascending mental artery from the sublingual artery was 7.1% in the studied population. All ascending mental arteries were 0.7 ± 0.2 mm in diameter at the mental protuberance and were branches of the submental artery that arose from the facial artery, except for two arteries that arose from the sublingual artery. Ultrasonographic study revealed that one left and one right sublingual artery from the lingual arteries penetrated the mylohyoid muscle near the midline to become the ascending mental artery in two volunteers. The ascending mental artery from the other side continued from the submental artery. CONCLUSION: Findings from the cadaveric dissections and ultrasonographic study revealed that the ascending mental artery may be a branch that continues from the lingual artery, or communicates with the sublingual artery through the mouth floor.

Ultrasound evaluation of arterial anastomosis of the forehead.

BACKGROUND: Color Doppler ultrasound has a potential role as an imaging guide in aiding filler injections which are blinded procedures. OBJECTIVE: This study investigated the forehead arteries and provided insight into their anastomoses. This was performed by challenging their function to provide blood through these anastomoses when the main artery was temporary occluded by compression. METHODS: Three arteries were identified on each side of the forehead, the supratrochlear, the supraorbital and the superficial temporal arteries. Under ultrasound monitoring, each target artery and corresponding anastomosis was studied separately by compressions performed in a sequential and accumulative manner. RESULTS: Data from the current study imply that accidental cannulation of either the supratrochlear artery or the supraorbital artery can cause ophthalmic artery embolization in every case recorded. If the frontal branch of the superficial temporal artery is cannulated, the chance of blindness as a complication occurs in one fifth of volunteers. Anastomosis between both sides of the terminal branches of ophthalmic arteries creates the possibility of bilateral ocular complications when accidental cannulation occurs at one of these branches, especially the supratrochlear artery. Thus, injury to the supratrochlear artery carries a greater risk of complication than the supraorbital artery. CONCLUSION: These findings emphasize that the chance of ocular complication is less when accidental cannulation occurs at the superficial temporal artery compared with injury to the supratrochlear or the supraorbital arteries as the terminal branches of the ophthalmic artery. Ultrasound can assist in the identification and evaluation of all the arteries at risk, thus avoiding the occurrence of vascular complications.

Non-specificity of Pitstop 2 in clathrin-mediated endocytosis.

Small molecule inhibitors of clathrin-mediated endocytosis are highly desired for the dissection of membrane trafficking pathways in the lab and for potential use as anti-infectives in the clinic. One inhibition strategy is to prevent clathrin from contacting adaptor proteins so that clathrin-mediated endocytosis cannot occur. "Pitstop" compounds have been developed that block only one of the four functional interaction sites on the N-terminal domain of clathrin heavy chain. Despite this limitation, Pitstop 2 causes profound inhibition of clathrin-mediated endocytosis. In this study, we probed for non-specific activity of Pitstop 2 by examining its action in cells expressing clathrin heavy chain harbouring mutations in the N-terminal domain interaction sites. We conclude that the inhibition observed with this compound is due to non-specificity, i.e. it causes inhibition away from its proposed mode of action. We recommend that these compounds be used with caution in cells and that they should not be used to conclude anything of the function of clathrin's N-terminal domain.