Zygomatic Implant Length Measurement Without Excessive Flap Release: A Human Cadaver Study.

One of the most important steps in zygomatic implant surgery is to determine the implant length. This cadaver study aims to identify an alternative technique for determining the length of the implant in zygoma surgery without excessive elevation of the flap. A total of 30 cadavers were included in this study. Measurements were made with a probe by seeing the exit point of the drills from the lateral aspect of the zygomatic bone. Secondly, without excessive flap release, the distance that the depth probe first raises the skin over the lateral border of the zygoma is measured. The average difference between the measurements made without excessive elevation of the flap and with a retractor placed on the zygomaticofrontal notch was found to be 5.41 ± 0.94 mm (range: 5-7.5 mm). According to the results of this study, the zygomatic implant should be placed at least 5 mm shorter than the length at which the depth probe first raises the skin over the lateral border of the zygomatic bone.

Intramuscular nerve distribution of the sternocleidomastoid muscle for the botulinum toxin injection.

PURPOSE: The aim of this study is to define the intramuscular nerve distribution of the sternocleidomastoid muscle (SCM) and the innervation zones (IZ) to describe the optimal botulinum toxin injection sites. METHODS: The cricoid cartilage (CC), laryngeal prominence (LP) and hyoid bone (HB) and angle of mandible (AM) were determined as landmarks. The length of the muscles were measured between the sternoclavicular joint and tip of the mastoid process. SCM was evaluated in two parts as anterior and posterior divided by the line where the length of the muscle was measured. Measurements were made to define the relationships of the SCM with common carotid artery, internal and external jugular veins. IZ were described according to these vessels. Afterwards, Modified Sihler's staining technique was applied to expose the intramuscular nerve distribution. RESULTS: The average length of SCM was 160,1 mm. Motor entry point of the accessory nerve fibers were between the AM-HB lines, in the range of 30-40% of the muscle length, and in the posterior part of the muscles. IZ were between the HB-CC lines in the anterior and posterior part. When this interval was examined according to the vessels, the optimal injection sites were between the LP-CC lines. CONCLUSIONS: This study shows the position of the intramuscular nerve fibers endings of the SCM according to the chosen landmarks and the relationship of the IZ with the vessels to prevent complications. These results can be used as a guide for safe and effective botulinum toxin injections with optimal quantities.

The Myrtiformis Muscle: Identification of a Forgotten Entity That Is Distinct From the Depressor Septi Nasi Muscle.

INTRODUCTION: Nasal musculature anatomy is a topic that plastic surgeons pay attention to. However, the presence and role of the myrtiformis muscle (MM) remain controversial. To elucidate these aspects, an anatomy-based study was conducted. MATERIALS AND METHODS: Seven midsagittally split and two total cadaver head's nasal bases, embalmed with modified Larssen solution (MLS), were dissected for MM anatomy. The features of this muscle were photographed, and a video of its function was recorded. RESULTS: It was found that MM originates from the maxillary alveolar process and continues as two heads, one reaching the alar base with spicular fibrotendinous endings and the other extending to depressor septi nasi fibers. Owing to its bi-vectoral muscle fibers, MM is found to constrict the nares by simultaneously forcing the alar base and lowering the columella. It was also found that left-sided muscles were larger than right-sided muscles. CONCLUSIONS: The MM is found to be a constrictor muscle of the nares in this study, contrary to recent observations.

A Feasible Technique for Transoral Endoscopic Thyroidectomy Through Vestibular Access Using a Single-port Technique: A Video Vignette in Cadaver Dissection.

BACKGROUND: The aim of this study was to evaluate the safety and feasibility of a single-port system for transoral endoscopic thyroidectomy with vestibular access (TOETVA). MATERIALS AND METHODS: Two embalmed human cadavers were used to test the single-port technique. After positioning, a median vestibular incision was made. Adipose tissue was dissected through the mentum with a Kelly clamp to reach the subplatysmal level. The Keyport Single Port System (Richard Wolf) was then inserted. After port placement, flexible endoscopic dissectors and a 5-mm endoscope were advanced. After removing the dissectors, we inserted the ArtiSential laparoscopic instruments. We also used a 3-port TOETVA on another human cadaver to compare the results with those of the single-port surgery. RESULTS: In the first cadaver, skin tension was observed during trocar insertion and dissection. Trocar insertion resulted in skin perforation in the submental area. In the second cadaver, the single-port trocar was successfully inserted despite the significant skin tension. However, the trocar did not allow the necessary surgical maneuvers to proceed with subsequent surgical steps and create a working space. Postprocedural anatomic dissection revealed that the distal branches of the mental nerve were related to the trocar passage. CONCLUSIONS: Our cadaver study demonstrated that single-port TOETVA is unsafe and not feasible with the current technology of the Keyport single-port system. This approach needs to be improved to perform this technique without injury to distal branches of the mental nerve, skin perforation, and other complications.

Modified Larssen solution (MLS)-fixed cadaver model for transoral endoscopic thyroidectomy vestibular approach (TOETVA) education: a feasibility study.

BACKGROUND: Training formats for transoral endoscopic thyroidectomy vestibular approach (TOETVA) are limited. Our aim was to create and investigate a TOETVA training model for general and ENT surgeons. METHODS: A total of 15 modified Larssen solution (MLS) human cadavers were used in the study. A day duration TOETVA human cadaver workshops were offered in two years consecutive. Post-training verbal and online questionnaires were applied to all trainers to evaluate course structure and program, organoleptic characteristics of MLS-fixed human cadavers, and TOETVA training effectiveness. Cost assessment is included in the study. RESULTS: Ninety-eight participants, i.e., 14 trainers and 84 hands-on (HO) and observer (OB) trainees, attended the workshops, completed the tasks assigned, and fulfilled the questionnaires. Implementation of all steps of TOETVA was approved positively by 89.8% of all participants, 94.4% of HO, and 83.3% of OB trainees. Regarding human cadaver and teaching quality, 10.8 ± 0.8 (10-12) human cadavers were "practical" by 13.2 (94.5%) of the trainers, and by 33.3 (92.5%) of the trainees for all steps of TOETVA. The cadavers were stored for 4.53 years and used 6.27 times repeatedly for endoscopic workshops and research studies. TOETVA workshop cost with repeatable use of MLS-fixed human cadaver is half of other performed TOETVA workshops. CONCLUSIONS: A TOETVA human cadaver workshop model has not been reported yet. Our findings suggest the feasibility of MLS-fixed human cadaver model for training of TOETVA, preserve the organoleptic properties necessary for the implementation of surgical steps, and reduce the cost.

Characterization of the mechanical properties of human parietal bones preserved in modified larssen solution, formalin and as fresh frozen.

PURPOSE: Although the fresh frozen (FF) cadaver is preferred for surgical applications, it is limited due to short usage time, unsuitable for reuse and the risk of infection. Due to its limited use, FF cadavers, which are covered by import in countries with insufficient body donation cause low-cost effectiveness. With the increase of real human tissue specimen necessities for surgical training, long-term preservation of the cadavers is crucial due to changes in mechanical properties. Therefore, studies on embalming solutions have increased in recent years. METHODS: We quantify the biomechanical properties of human parietal bones preserved via modified larssen solution (MLS) and compare the results with the specimens preserved as FF and fixed with 10% formalin-based solution (F10). The rectangular samples of 24 parietal bones of male individuals were resected from MLS-embalmed, F10-embalmed and FF cadavers to form three groups each containing eight samples. These specimens were tested longitudinally to identify mechanical properties. RESULTS: The tensile test results showed that there is not a significant difference between the groups in terms of stiffness, elastic modulus, strain at ultimate stress, failure strain and effective plastic strain. However, the yield stress, ultimate stress, yield strain, failure stress and total energy and post-yield properties are significantly lower in F10 than MLS and FF groups. CONCLUSION: It is observed that the mechanical properties of MLS preserved and FF parietal bones have almost similar properties. Thus, it can be concluded that MLS is a suitable fixative solution for bone studies and bone-related surgical anatomy training applications.

A surgical and anatomo-histological study on Transoral Endoscopic Thyroidectomy Vestibular Approach (TOETVA).

BACKGROUND: The number of TOETVA surgeries has increased worldwide but the anatomical passage of trocars is not clearly defined. We aimed to define detailed surgical anatomical passage of the trocars in cadavers. The incisions in oral vestibule, anatomical pathways of trocars, affected mimetic muscles, neurovascular relations of trocars and histological correlation of surgical anatomy were investigated. METHODS: Four cadavers and 6 six patient oral vestibules were used. The locations of optimised vestibular incisions were measured photogrammetrically. Initial steps of TOETVA surgery were performed on cadavers according to those optimal incisions. TOETVA preformed cadavers dissected to determine anatomical passages of the trocars. Afterwards, flap of lower lip and chin were zoned by software appropriate to the trocars routes. Histological analyses of the zones were made in correlation with dissections. RESULTS: Mimetic muscles associated with median (MT) and lateral trocars (LT) are orbicularis oris, mentalis, depressor anguli oris, depressor labii inferioris and platysma muscles. Trocars affect mimetic muscles in the perioral, chin and submental regions in different ways. The risk of mental nerve injury by MT is low. LT pass through the DLI muscle. The transmission of LT to the subplatysmal plane in the submental regions can be in two different ways. The arterial injury risk is higher with LT than the MT. CONCLUSIONS: The surgical anatomy of the perioral, chin and submental regions for the initial TOETVA steps has been defined. Detailed surgical anatomical passages of the MT and LT were determined. Anatomical pattern to reach subplatysmal plane are presented. Mimetic muscles effected by trocars were determined. Endocrine surgeons should know the anatomical passage of TOETVA trocars.

The modified lateral supraorbital approach.

PURPOSE: Lateral supraorbital approach is a simpler and quicker method than pterional approach. It provides a more anterior projection when compared to the pterional approach. There are some minor differences of the modified lateral supraorbital approach when compared to lateral supraorbital approach. It is directed more subfrontally and anterior than the pterional and lateral supraorbital approach. MATERIAL AND METHODS: We used modified lateral supraorbital approach in 100 cases between 2012 and 2015 in Medical Park Izmir Hospital/Turkey. The assessed data were as follows: age, gender, Glasgow coma scale at admission, the localization of pathology, the condition of surgical obliteration for aneurysm, excision grade for meningioma, length of stay in the hospital and Glasgow outcoma scale at discharge. RESULTS: Of all patients, 58 (58%) were men and 42 (42%) were women. Our cases were anterior communicating artery aneurysms (41 cases), tuberculum sella and medial sphenoid wing meningiomas (22 cases), middle cerebral artery aneurysms (15 cases), olfactory groove meningiomas (15 cases), anterior choroidal artery aneurysms (4 cases) and posterior communicating artery aneurysms (3 cases). 4 patients died and the mortality rate of the study cohort was 4%. CONCLUSIONS: The MLSA is faster, simpler and less invasive than the PA and LSA.

Useful Effects of Melatonin in Peripheral Nerve Injury and Development of the Nervous System.

This review summarizes the role of melatonin (MLT) in defense against toxic-free radicals and its novel effects in the development of the nervous system, and the effect of endogenously produced and exogenously administered MLT in reducing the degree of tissue and nerve injuries. MLT was recently reported to be an effective free radical scavenger and antioxidant. Since endogenous MLT levels fall significantly in senility, these findings imply that the loss of this antioxidant could contribute to the incidence or severity of some age-related neurodegenerative diseases. Considering the high efficacy of MLT in overcoming much of the injury not only to the peripheral nerve but also to other organs, clinical trials for this purpose should be seriously considered.

Cadaver embalming fluid for surgical training courses: modified Larssen solution.

PURPOSE: 10% Formalin (F10)-fixed cadavers have disadvantages such as disturbing smell, mucosal irritation, discoloration and rigidity. We aimed to determine a suitable, simple and cost-effective embalming method that preserves color, texture, pliability and flexibility of the tissues for a long time without a disturbing smell and mucosal irritation. The embalmed cadavers were expected to be durable against environmental effects, utilizable for multiple and repetitive surgical trainings and instrumentations. METHODS: Eight male (six intact, two autopsied bodies) and four female (three intact and one imported trunk) human cadavers were preserved with modified Larssen solution (MLS). Preserved bodies were kept in the deep freezers at -18/-20 °C. Bodies were allowed to thaw at room temperature 3 days prior to use. They were used in postgraduate hands-on courses for several medical disciplines. Each course lasted at least 1 day and during this period the bodies were stayed at room temperature. Assessments of 30 trainers and 252 trainees were collected during the courses. Additionally, the organoleptic characteristics of the fresh frozen (FF), preserved with MLS and F10-fixed cadavers were compared. RESULTS: The colors of muscles, fasciae, fatty tissue, nerves and vessels were evaluated and life-like tissues of MLS cadavers were impressive. There were no obvious or disturbing smell and sign of putrefaction of the MLS cadavers. CONCLUSIONS: MLS is a sustainable and relatively affordable soft cadaver embalming method. Its application is same as in other conventional methods and does not need new equipment. This article indicates the success of the MLS method in human cadavers.

Revisiting the Anatomy of the Facial Recess: The Boundaries of the Round Window Exposure.

BACKGROUND: The exposure of the round window (RW) through the facial recess (FR) is sometimes partial. The anatomic variations that alter RW exposure during cochleostomy have not been clearly defined to date. AIMS: The aim of this study was to assess the best FR position in which to achieve the widest exposure of the RW niche and to define the topographic relationship between two other important anatomical structures, the facial nerve (FN) and the chorda tympani (CT). STUDY DESIGN: Cadaver study. METHODS: Twenty-four temporal bones were included in the study. Anterior and posterior epitympanectomy and posterior tympanotomy were performed after mastoidectomy. Bone was removed until the FN and CT were skeletonized and the CT branching point was visible. Two pictures were taken. The first was taken when the facial recess was at its widest exposure, while the second was taken when the RW niche was maximally exposed through the facial recess. Various measurements were taken. RESULTS: The RW niche was totally visible in 19 temporal bones (79.2%). The RW was partially visible in the remaining five bones (20.8%). The unexposed part of the RW lay posteromedial to the FN in these five bones. While the branching point of the CT could be visualized in all cases at the widest exposure of RW, the part of the FN distal to the branching point was hidden in eight subjects (33.3%) under the posterior wall of the external ear canal. CONCLUSIONS: The RW niche was totally visible in most of the temporal bones. The RW lay posteromedial to the FN in some cases and total exposure was impossible.

Anatomic Basis for Penis Transplantation: Cadaveric Microdissection of Penile Structures.

We present a cadaveric dissection study to investigate the anatomic feasibility of penile transplantation. Seventeen male cadavers were dissected to reveal detailed anatomy of the dorsal neurovascular structures including dorsal arteries, superficial and deep dorsal veins, and dorsal nerves of the penis. Dorsal artery diameters showed a significant decrease from proximal to distal shaft. Dominance was observed in one side. Deep dorsal vein showed a straight course and less decrease in diameter compared to artery. Dorsal nerves showed proximal branching pattern. In a possible penile transplantation, level of harvest should be determined according to the patient and the defect, where a transgender patient will receive a total allograft and a male patient with a proximal penile defect will receive a partial shaft allograft. We designed an algorithm for different levels of penile defect and described the technique for harvest of partial and total penile transplants.

Redesign and treatment planning orbital floor reconstruction using computer analysis anatomical landmarks.

Orbital floor fractures are one of the most commonly encountered maxillofacial fractures due to their weak anatomical structure. Restoration of the orbital floor following a traumatic injury or a tumor surgery is often difficult due to inadequate visibility and lack of knowledge on its anatomical details. The aim of this study is to investigate the locations of the inferior orbital fissure (IOF), infraorbital groove (G), and infraorbital foramen (Fo) and their relationship with the orbital floor using a software. Measurements from the inferior orbital rim (IOR) using the Fo, the IOF, G, and the optic canal (OC) were calculated in 268 orbits as reference points. The surgical landmarks from the G and the OC, the G and the IOF, the G and the intersection point were measured as 31.6 ± 6, 12.9 ± 4, and 12 ± 5 mm, respectively. The mean distances between the G and the IOR, the Fo and the IOF, and the Fo and the OC were found as 8.3 ± 2.1, 28.7 ± 3.5, and 53.6 ± 5.9 mm, respectively. The mean angles were calculated as OC-IOF-G 68.1° ± 16.4°; intersection-G-IOF as 61.4° ± 15.8°; IOF-OC-G as 19° ± 5.5°; OC-G-intersection as 31.5° ± 11.9°, G-intersection-OC as 129.5°, IOF-intersection-G as 50.5°. Furthermore, variable bony changes on the orbital floor which may lead to the differences at intersection point of the G and Fo were determined. In 28 specimens (20.9 %), unilateral accessory Fo (AcFo) was present. In 27 specimens, AcFo was situated supermaedially (96.4 %) on the main aperture. In one specimen, two intraorbital canals and Fo emerged from different points and coursed into different apertures. The measured mean distances of the AcFo-IOR and the AcFo-Fo were as 7 ± 2 and 7.3 ± 3.2 mm, respectively. The primary principle in the oculoplastic treatment of orbital floor reconstructions must be repositioning the herniated orbital aperture by maintaining the infraorbital artery and the nerve in the orbital floor. The IOF and the G were recommended as the more reliable oculoplastic surgical landmarks for identifying the orbital floor. To avoid pinching of the orbital floor structures, the triangle (IS-G-IOF) should be equilateral with an exigence of a 70° angle within it. Among each distance of the intersection-IOF, IOF-G, G-intersection should be equal. With the help of certain software, this study made possible to investigate the variability of the orbital floor structures, observe the variety in measurements and calculate the parameters which are crucial in implementing personalized reconstruction and implanting support.

Three-dimensional evaluation of the danger zone of ethmoidal foramens on the frontoethmoidal suture line on the medial orbital wall.

INTRODUCTION: It is clear that the importance of the ethmoidal foramen (EF) is based on its vascular contents. The frontoethmoidal suture (FS) line is recommended as more reliable navigational landmark for identifying the EF. MATERIALS AND METHODS: The vertical orientation between the EF and the FS line was studied in 188 orbits using a computer software program. RESULTS: 146 anterior EFs (77.7 %) and 42 anterior EFs (22.3 %) were situated in the FS line as intrasutural and extrasutural, respectively. 146 posterior EFs (77.25 %) and 8 posterior EFs (4.25 %) were presented as intrasutural and extrasutural, respectively. Although accessory EFs were detected in 25.5 % specimen exhibited an extrasutural location. Majority of the EFs (1-4 EFs) were situated on the FS line. The mean distances from the FS and the anterior EF, the posterior EF and the accessory EF were measured as 2.1 ± 0.5, 2.0 ± 1.5 and 2.3 ± 1.2 mm, respectively. The range of the distances from the FS to the anterior EF, posterior EF and accessory EF were -1.2 to 3.32 , -1.02 to 5.76 and -1.1 to 3.65 mm, respectively. CONCLUSION: The ranges of EF changed within 1-6 mm. As the FS is not a single point, it is more suitable to make the incision 7 mm above the suture line. The data from this study to help the orbital surgeons explain and avoid unexpected hemorrhage during the orbital procedures such as posttraumatic orbital reconstruction, orbital tumor resections, anterior skull base reconstruction, and orbital decompression surgery.

Computer-assisted analysis of anatomical relationships of the ethmoidal foramina and optic canal along the medial orbital wall.

Typically, the medial orbital wall contains an anterior ethmoidal foramen (EF) and a posterior EF, but may also have multiple EFs transmitting the arteries and nerves between the orbit and the anterior cranial fossa. The aim of this study is to determine a patient-friendly landmark of the medial orbital wall and to specify a precise location of the ethmoidal foramens (EF) in order to standardize certain anatomical marks as safe ethmoidal arteries. Orientation points on the anterior ethmoidal foramen (AEF), posterior ethmoidal foramen (PEF) and middle ethmoidal foramen (MEF) were investigated in 262 orbits. Using a software program, distances between each foramen and the midpoint of the anterior lacrimal crest (ALC), the optic canal (OC), and some important angles were measured. The EFs were identified as single in 0.8%, double in 73.7%, triple 24,4% and quadruple in 1.1% specimens. The mean distances between ALC and AEF, ALC and PEF and ALC and MEF were 27.7, 10.6, and 12.95 mm, respectively. The distances from ALC-AEF, AEF-PEF, and PEF-OC were 27.7 ± 2.8, 10.6 ± 3.3, 5.4 ± 1 mm. The angles from the plane of the EF to the medial border of the OC were calculated as 13.2° and 153°, respectively. The angle from the AEF to the medial border of the OC was based on the plane between the ALC and AEF was 132°. The occurrence of multiple EF with an incidence of 25% narrows the borders of the safe region in the medial orbital wall. Safe distance of the ALC-EF was measured as 22.1 mm on medial wall. The line of the location of the EF was calculated 16.2 mm. In this study, it was possible to investigate the variability of the orbital orifice of the EF and the feasibility of the EA, to observe various angles of the orbital wall bones and to calculate the lengths of some parameters with the help of certain software.

Submandibular artery: bilobed platysma myocutaneous flap for total lower lip reconstruction.

BACKGROUND: Lower lip reconstruction following cancer resection includes a variety of clinical and microsurgical options. OBJECTIVE: We have developed a myocutaneous flap for full thickness reconstruction with a functioning muscle. TECHNIQUE: In all patients, the submandibular artery was outlined using computerized tomographic angiography and Doppler. The flap was designed after resection. The first lobe was designed to fill the defect and was outlined 90° from the defect margin, with the submandibular artery in the center of the flap. A second lobe was then outlined 90° from the first lobe. The flap was raised along with the platysma muscle and artery, with the first lobe rotated to the lip and the second lobe inset into the first lobe site, permitting neck closure without skin redundancy. RESULTS: From January to May 2012, 17 patients were treated with this flap, and all flaps survived. All of the patients had oral continence at sixteen months, and electromyography documented platysma function. CONCLUSION: The flap provides single-stage lower lip reconstruction with functional muscle.

Navigational area of the cranio-orbital foramen and its significance in orbital surgery.

The cranio-orbital foramen (COF) is located on the lateral wall of the orbit. It is a potential source of hemorrhage during deep lateral orbital dissection, since it functions as an anastomosis between the lacrimal artery and the middle meningeal artery. The aim of this study was to guide and facilitate the surgical procedures in the orbit, so as to determine a navigational area and the precise location of the COF and to standardize certain anatomical marks. The navigational area of the COF and topographical features were studied in 75 craniums with presented COF. 33 bilateral main COFs, 41 (18 on the right, 23 on the left) unilateral main COFs at the main cranium and 19 accessory COFs were studied for their navigational features on the orbit. The distances between the COF and the fronto-zygomatic suture, supraorbital notch, lateral angle of the superior orbital fissure (SOF) and Whitnall's tubercle were measured. The mean distance of the COF from the fronto-zygomatic suture, supraorbital notch, lateral angle of the SOF and Whitnall's tubercle was 26.3, 37.3, 92 and 27.1 mm, respectively. For the navigational area signs of the COF, areas of the orbit that form the transversal and vertical lines are generated on the reference points. Whilst the upper outer area of the orbit contains a potential bleeding risk, the bottom section of the outer column is identified as safe for the surgical operations of the lateral orbital wall. The fronto-zygomatic suture and Whitnall's tubercle are recommended as the most reliable navigational landmarks for identifying the COF. Hence, the transversal and vertical orientation of the COF should be mastered by the surgeons reconstructing the anterior base of the skull and the orbit.