Identification of the trochlea with reference to the lacrimal caruncle, and its significance as a landmark in orbitofacial surgery

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.

Three-Dimensional Topography of the Supratrochlear Nerve With Reference to the Lacrimal Caruncle, and Its Danger Zone in Asians

BACKGROUND

The supratrochlear nerve (STN) is relatively superficial and therefore vulnerable to iatrogenic injury.

OBJECTIVE

To elucidate the course of STN with reference to the lacrimal caruncle, with the aim of preventing nerve injury during surgery in the forehead region.

MATERIALS AND METHODS

Thirty-four hemifaces from 18 Korean cadavers were dissected. The vertical line through the apex of lacrimal caruncle and the horizontal line through the supraorbital margin were used as horizontal and vertical reference lines, respectively. The course of STN in the frontal view and the point at which it pierced the overlaying musculature were examined.

RESULTS

After exiting the corrugator muscle cushion, the STN enters the subcutaneous plane by piercing the frontalis muscle. These piercing points occurred at mean horizontal and vertical distances relative to the medial branch of the STN of 9.2 and 9.6 mm, respectively; the corresponding distances for the lateral branch of the STN were 1.1 and 15.3 mm, respectively.

CONCLUSION

When performing surgery in the medial forehead region, the surgeon must ensure that the dissection plane of forehead tissue is more superficial: superiorly within 1.5 cm from the supraorbital margin and medially within 1.0 cm from the vertical line through the apex of lacrimal caruncle.

Topography of the supraorbital nerve with reference to the lacrimal caruncle: danger zone for direct browplasty

PURPOSE

To elucidate the course of the supraorbital nerve (SON) with reference to the lacrimal caruncle in order to facilitate safer direct browplasty by preventing nerve injury.

METHODS

Thirty-four hemifaces from 18 embalmed Korean cadavers were dissected. A vertical line through the upmost point of the lacrimal caruncle and a horizontal line through the supraorbital margin were used as the horizontal and vertical reference positions, respectively. The course of the SON in the frontal view and the point at which it pierced the overlaying musculature were examined.

RESULTS

The SON divides into a superficial branch and a deep branch just after exiting the orbit. In all cases, the deep SON remains in the subgaleal plane deep to the corrugator and frontalis muscles. The superficial SON travels under the corrugator muscle dividing into three branches (medial, intermediate and lateral) and pierced the frontalis muscle at 19-32 mm above the supraorbital margin. However, in 11 cases (32%) the medial branch of the superficial SON pierced the lower portion of the corrugator muscle at 3.6 mm above the supraorbital margin and ran in front of the muscle along with the vertical line through the upmost point of the lacrimal caruncle.

CONCLUSIONS

One-third of the medial branch of the superficial SON without corrugator muscle protection is vulnerable to iatrogenic injury during direct browplasty. Therefore, the oculofacial surgeon must bring the dissection plane of the forehead tissue more superficially around the vertical line through the upmost point of the lacrimal caruncle in order to avoid nerve injury.

Location of the inferior oblique muscle origin with reference to the lacrimal caruncle and its significance in oculofacial surgery

PURPOSE

To identify the location of the inferior oblique muscle (IOM) origin with reference to the lacrimal caruncle in order to facilitate safer oculofacial surgery by preventing morbidity associated with IOM injury.

METHODS

Thirty-seven intact orbits of 20 embalmed Asian cadavers were dissected. The location of the medial border of the IOM origin was determined with respect to the apex of the lacrimal caruncle. In addition, the size of the IOM origin and the anteroposterior distance from the inferior orbital rim to the anterior border of the IOM origin were measured.

RESULTS

The IOM origin was located at a mean distance of 1.2 mm lateral and 11.2 mm inferior to the apex of the lacrimal caruncle. In half of the orbits, the IOM origin was situated just on the vertical line through the apex of the lacrimal caruncle. The mean length and width of the IOM origin were 4.3 and 2.7 mm, respectively. The mean anteroposterior distance from the inferior orbital rim to the IOM origin was 1.9 mm.

CONCLUSIONS

The lacrimal caruncle is easily identifiable and a reliable external landmark for prediction of the IOM origin. The IOM origin is located approximately where the vertical line through the apex of the lacrimal caruncle intersects the inferior orbital rim. The findings of this anatomical study of the exact location of the IOM origin can help to improve the safety of oculofacial surgery.