Quantifying Lateral Frontal Sinus Access: The Upper Blepharoplasty Approach.

OBJECTIVE: Despite advances in technology and instrumentation, access to the lateral frontal sinus remains a challenge for surgeons. We sought to quantify the reach and applicability of the upper blepharoplasty approach (UBA) to the frontal sinus. METHODS: Twelve cadaveric specimens were obtained for anatomic research and frontal sinuses divided into 3 zones. Zone 1 was defined as medial to the supraorbital neurovascular bundle (SON). The remaining orbit was then bisected to define zone 2 (centrally) and zone 3 (laterally). Twenty-four UBAs were performed followed by 12 modified endoscopic Lothrop procedures (MELP). The ability to instrument each wall of the frontal sinus was recorded for the MELP, UBA, and combined approach. RESULTS: The UBA provided excellent access to the lateral frontal sinus in zones 2 and 3 (89% and 100%). The MELP provided poorer access in zone 3 (67%) but improved access in zone 1 (83%-100%). Access for zone 1 through the UBA was limited. The combined approach yielded 100% access to each frontal sinus boundary. CONCLUSION: The MELP in combination with the UBA/lateral trephination provides excellent access to each frontal sinus boundary. The UBA provides excellent access to the lateral frontal sinus but is limited medially by the SON.

Forehead anatomy: arterial variations and venous link of the midline forehead flap.

The largest prospective cadaver study done over a 3-year period to investigate the arterial variations of the forehead is presented. The primary goal was to find anatomical support for various forehead flaps previously designed. Thirty cadaver foreheads (60 hemi-foreheads) were dissected from deep to superficial to identify arterial variations. The arteries were filled with a latex solution prior to dissection. The results show that the supratrochlear and dorsal nasal arteries have a relatively constant origin. Vertical (VB), oblique (OB), medial (MB) and lateral branches (LB) of the supraorbital artery were identified. The frontal branch of the superficial temporal artery (FBSTA) was found to continue in the direction of the scalp at the lateral orbital rim vertical line and gave off a transverse branch, the transverse frontal artery (TFA), to supply the forehead. The oblique branch of the supraorbital artery (OBSOA) most often anastomosed with either the transverse frontal artery or the frontal branch of the superficial temporal artery at the lateral orbital rim vertical line. A central artery (CA) was consistently found originating from the dorsal nasal artery usually 5mm from its origin. The central artery had a constant anastomosis with the opposite central artery in the inferior transverse third of the forehead. The central artery was not easily identifiable in the superior third of the forehead. The angular artery (AA) was found to have a variable termination. The angular artery could communicate with the supratrochlear artery (STrA) at the supraorbital rim (SOR) or it could continue up into the forehead medial to the STrA. This artery was called the paracentral artery (PCA). The central artery, paracentral artery and supratrochlear artery have an important relationship with the most prominent central vein that is relevant to flap construction. The significance of the central artery and vein favours the median forehead flap as anatomically superior and the prominent central vein is a constant landmark on which to select the side of the pedicle. Clear landmarks for defining the pedicle base for the median forehead flap are provided.

Nasal and frontal sinus mucosa of the adult dog contain numerous olfactory sensory neurons and ensheathing glia.

Olfactory glial cells have been the focus of much recent research interest because of their possible future use as cellular transplants in repair of spinal cord injury. Although olfactory glial cells can be collected from the olfactory bulb for in vitro culture, alternative sites would be preferable for safer surgical access. This study was designed to investigate the distribution of olfactory sensory neurons and olfactory glial cells within the canine peripheral olfactory system. Using immunohistochemistry and electron microscopy on perfused tissue we demonstrate that olfactory sensory neurons are found in both the caudal nasal and the frontal sinus epithelia. Olfactory ensheathing glia were found in the mucosa at both these sites implying that surgical access for harvesting cells for transplantation would be straightforward.

The trigeminal nerve. Part II: the ophthalmic division.

The ophthalmic, or first division (V1) of the trigeminal nerve, is the smallest of the three divisions and is purely sensory or afferent in function. It supplies sensory branches to the ciliary body, the cornea, and the iris; to the lacrimal gland and conjunctiva; to portions of the mucous membrane of the nasal cavity, sphenoidal sinus, and frontal sinus; to the skin of the eyebrow, eyelids, forehead, and nose; and to the tentorium cerebelli, dura mater, and the posterior area of the falx cerebri. At first glance, one might not expect one interested in the diagnosis and treatment of orofacial pain and temporomandibular joint disorders to have a need to be concerned with the ophthalmic division. Although much of this division's influence is dedicated to structures within the orbit, nose, and cranium, still, the ophthalmic division may be afflicted with a lesion or structural disorder which can cause all sorts of orofacial pain. Ignorance of this or any portion of the trigeminal nerve will lead to diagnostic and therapeutic failures. In this, the second of four (4) articles concerning the trigeminal nerve, the first division of this vast cranial nerve will be described in detail.