CMOS-based cryogenic control of silicon quantum circuits.

The most promising quantum algorithms require quantum processors that host millions of quantum bits when targeting practical applications1. A key challenge towards large-scale quantum computation is the interconnect complexity. In current solid-state qubit implementations, an important interconnect bottleneck appears between the quantum chip in a dilution refrigerator and the room-temperature electronics. Advanced lithography supports the fabrication of both control electronics and qubits in silicon using technology compatible with complementary metal oxide semiconductors (CMOS)2. When the electronics are designed to operate at cryogenic temperatures, they can ultimately be integrated with the qubits on the same die or package, overcoming the 'wiring bottleneck'3-6. Here we report a cryogenic CMOS control chip operating at 3 kelvin, which outputs tailored microwave bursts to drive silicon quantum bits cooled to 20 millikelvin. We first benchmark the control chip and find an electrical performance consistent with qubit operations of 99.99 per cent fidelity, assuming ideal qubits. Next, we use it to coherently control actual qubits encoded in the spin of single electrons confined in silicon quantum dots7-9 and find that the cryogenic control chip achieves the same fidelity as commercial instruments at room temperature. Furthermore, we demonstrate the capabilities of the control chip by programming a number of benchmarking protocols, as well as the Deutsch-Josza algorithm10, on a two-qubit quantum processor. These results open up the way towards a fully integrated, scalable silicon-based quantum computer.

The collateral map: prediction of lesion growth and penumbra after acute anterior circulation ischemic stroke.

OBJECTIVES: This study evaluated the collateral map's ability to predict lesion growth and penumbra after acute anterior circulation ischemic strokes. METHODS: This was a retrospective analysis of selected data from a prospectively collected database. The lesion growth ratio was the ratio of the follow-up lesion volume to the baseline lesion volume on diffusion-weighted imaging (DWI). The time-to-maximum (Tmax)/DWI ratio was the ratio of the baseline Tmax > 6 s volume to the baseline lesion volume. The collateral ratio was the ratio of the hypoperfused lesion volume of the phase_FU (phase with the hypoperfused lesions most approximate to the follow-up DWI lesion) to the hypoperfused lesion volume of the phase_baseline of the collateral map. Multiple logistic regression analyses were conducted to identify independent predictors of lesion growth. The concordance correlation coefficients of Tmax/DWI ratio and collateral ratio for lesion growth ratio were analyzed. RESULTS: Fifty-two patients, including twenty-six males (mean age, 74 years), were included. Intermediate (OR, 1234.5; p < 0.001) and poor collateral perfusion grades (OR, 664.7; p = 0.006) were independently associated with lesion growth. Phase_FUs were immediately preceded phases of the phase_baselines in intermediate or poor collateral perfusion grades. The concordance correlation coefficients of the Tmax/DWI ratio and collateral ratio for the lesion growth ratio were 0.28 (95% CI, 0.17-0.38) and 0.88 (95% CI, 0.82-0.92), respectively. CONCLUSION: Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. Further studies are needed to generalize the findings of this study. CLINICAL RELEVANCE STATEMENT: Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. KEY POINTS: • Cell viability in cerebral ischemia due to proximal arterial steno-occlusion mainly depends on the collateral circulation. • The collateral map shows salvageable brain extent, which can survive by recanalization treatments after acute anterior circulation ischemic stroke. • Precise estimation of salvageable brain makes it possible to make patient-specific treatment decision.

Sihler's staining technique: How to and guidance for botulinum neurotoxin injection in human muscles.

The Sihler's stain is a whole-mount nerve staining technique that allows visualization of the nerve distribution and permits mapping of the entire nerve supply patterns of the organs, skeletal muscles, mucosa, skin, and other structures that contain myelinated nerve fibers. Unlike conventional approaches, this technique does not require extensive dissection or slide preparation. To date, the Sihler's stain is the best tool for demonstrating the precise intramuscular branching and distribution patterns of skeletal muscles. The intramuscular neural distribution is used as a guidance tool for the application of botulinum neurotoxin injections. In this review, we have identified and summarized the ideal botulinum neurotoxin injection points for several human tissues.

Sonoanatomy of injecting botulinum neurotoxin into the facial muscles.

INTRODUCTION: Ultrasonography (US) has become an essential tool for guiding botulinum neurotoxin (BoNT) injections in facial muscles, enhancing precision and safety. This narrative review explores the role of US in BoNT administration, particularly in complex anatomical regions, highlighting its impact on treatment customization, real-time visualization, and complication reduction. MATERIALS AND METHODS: A comprehensive literature search was conducted using PubMed, MEDLINE, Embase, and Cochrane Library for articles published from January 2018 to December 2023. Search terms included "Botulinum neurotoxin," "facial anatomy," "ultrasonography guided injection," and "facial muscle sonoanatomy." Studies focusing on US-guided BoNT injections in facial muscles were included. Data extraction and synthesis were performed independently by two reviewers, focusing on study design, ultrasonography techniques, outcomes, and conclusions. RESULTS: The review found that US guidance significantly enhances the precision of BoNT injections by providing real-time visualization of facial muscles and blood vessels, thereby reducing the risk of adverse events. US enables tailored injection strategies, ensuring symmetrical facial expressions and minimizing over-treatment. The technique also offers immediate feedback, allowing for on-the-spot adjustments to improve treatment efficacy and safety. However, the review identified limitations, including potential selection bias and variability in US techniques across different studies. CONCLUSION: US guidance for BoNT injections into facial muscles offers substantial benefits in terms of precision, safety, and treatment customization. Despite the identified limitations, the integration of US into clinical practice is poised to enhance patient outcomes in aesthetic and therapeutic procedures. Further research is needed to standardize US techniques and broaden the inclusivity of studies to validate these findings comprehensively.

Anatomical analysis of the motor endplate zones of the suprascapular nerve to the infraspinatus muscle and its clinical significance in managing pain disorder.

Myofascial pain syndrome caused by myofascial trigger points is a musculoskeletal disorder commonly encountered in clinical practice. The infraspinatus muscle is the region most frequently involved in the myofascial pain syndrome in the scapular region. The characteristics of the myofascial trigger points are that they can be found constantly in the motor endplate zone. However, localizing myofascial trigger points within the motor endplate zone and establishing an accurate injection site of the infraspinatus muscle has been challenging because the anatomical position of the motor endplate zone of the infraspinatus muscle is yet to be described. Therefore, this cadaveric study aimed to scrutinize the motor endplate zone of the infraspinatus muscle, propose potential myofascial trigger points within the muscle, and recommend therapeutic injection sites. Twenty specimens of the infraspinatus muscle for nerve staining and 10 fresh frozen cadavers for evaluation of the injection were used in this study. The number of nerve branches penetrating the infraspinatus muscle and their entry locations were analyzed and photographed. Modified Sihler's staining was performed to examine the motor endplate regions of the infraspinatus muscle. The nerve entry points were mostly observed in the center of the muscle belly. The motor endplate was distributed equally throughout the infraspinatus muscle, but the motor endplate zone was primarily identified in the B area, which is approximately 20-40% proximal to the infraspinatus muscle. The second-most common occurrence of the motor endplate zone was observed in the center of the muscle. These detailed anatomical data would be very helpful in predicting potential pain sites and establishing safe and effective injection treatment using botulinum neurotoxin, steroids, or lidocaine to alleviate the pain disorder of the infraspinatus muscle.

Prognostic value of collateral perfusion estimation by arterial spin labeling for acute anterior circulation ischemic stroke.

PURPOSE: This study aimed to verify the value of arterial spin labeling (ASL) collateral perfusion estimation for predicting functional outcomes in acute anterior circulation ischemic stroke. METHODS: This secondary analysis of an ongoing prospective observational study included data from participants with acute ischemic stroke due to steno-occlusion of the internal carotid artery and/or the middle cerebral artery within 8 h of symptom onset. We compared the collateral map, which is a 5-phase collateral imaging derived from dynamic contrast-enhanced magnetic resonance angiography, and ASL to validate the ASL collateral perfusion estimation. Multiple logistic regression analyses were conducted to identify independent predictors of favorable functional outcomes. RESULTS: One hundred forty-eight participants (68 ± 13 years, 96 men) were evaluated. The ASL collateral perfusion grade was positively correlated with the collateral perfusion grade of the collateral map (P < .001). Younger age (OR = 0.53, 95% CI = 0.36-0.78, P = .002), lower baseline NIHSS score (OR = 0.85, 95% CI = 0.78-0.92, P < .001), intermediate ASL collateral perfusion grade (OR = 4.02, 95% CI = 1.43-11.26, P = .008), good ASL collateral perfusion grade (OR = 26.37, 95% CI = 1.06-655.01, P = .046), and successful reperfusion (OR = 5.84, 95% CI = 2.08-16.42, P < .001) were independently associated with favorable functional outcomes. CONCLUSION: ASL collateral perfusion estimation provides prognostic information, which can be helpful in guiding management decisions.

Distribution of the intramuscular innervation of the triceps brachii: Clinical importance in the treatment of spasticity with botulinum neurotoxin.

This study aimed to identify ideal sites for botulinum toxin injection by analyzing the intramuscular nerve patterns of the triceps brachii muscles. A modified Sihler's method was applied to the triceps brachii muscle (15 specimens), with long, medial, and lateral heads. The intramuscular arborization areas of the long, medial, and lateral heads of the triceps brachii muscle were measured as a percentage of the total distance from the midpoint of the olecranon (0%) to the anteroinferior point of the acromion (100%), by dividing the medial and lateral parts based on the line connecting the midpoint of the olecranon and the anteroinferior point of the acromion. Intramuscular arborization patterns were observed at the long head at two medial regions, proximally 30%-50% and distally 60%-70%; medial head of 30%-40%; and lateral head of 30%-60%. These results suggest that the treatment of spasticity of the triceps brachii muscles involves botulinum toxin injections in specific areas. The areas corresponding to the areas of maximum arborization are recommended as the most effective and safe points for botulinum toxin injection.

A three-dimensional analysis of the tibialis anterior tendon: emphasizing tendon insertion patterns for effective repair and understanding hallux valgus development.

PURPOSE: The present study aimed to evaluate the insertion site of the tibialis anterior tendon three-dimensionally. METHODS: Seventy lower limbs were dissected. The tibialis anterior tendon was dissected to verify the insertion site to the medial cuneiform and the base of the first metatarsal bone. The three-dimensional (3D) territory of the tibialis anterior tendon insertion on the medial cuneiform and the first metatarsal bones was measured on a reconstructed 3D model. RESULTS: The insertion pattern of the tibialis anterior tendon was classified into three types, the most common being Type I: a single tibialis anterior tendon dividing into two equal-sized bands to the medial cuneiform and base of the first metatarsal bone (57.1%, 40/70 of cases). The 3D territory of the tibialis anterior tendon was larger in the plantar aspect than in the medial side of both the medial cuneiform and the base of the first metatarsal bone. The width of the tendon inserted into the medial cuneiform was wider than that inserted into the first metatarsal bone. CONCLUSION: The tibialis anterior tendon was more commonly attached to the plantar part than the medial part in both the medial cuneiform and the base of the first metatarsal bone. This anatomical information will help surgeons perform anatomical reconstruction of the tibialis anterior tendon, reduce further tendon damage in the first metatarsocuneiform joint area and also provide valuable knowledge to improve understanding of hallux valgus pathogenesis.

Anatomical analysis of the intramuscular distribution patterns of the levator scapulae and the clinical implications for pain management.

PURPOSE: The present study aimed to demonstrate the intramuscular nerve distribution of the levator scapulae muscle that is responsible for pain and to use this anatomic data to propose possible injection sites. METHODS: Twenty levator scapulae muscles were dissected from 16 Korean embalmed cadavers. The intramuscular nerve distribution of the levator scapulae muscle was identified by whole-mount nerve staining to preserve and stain the nerve fibers without damage. RESULTS: The posterior ramus of spinal nerves C3, C4, and C5 innervated the levator scapulae muscles. When the origin and insertion of the muscle were set to 0% and 100%, respectively, most of the intramuscular nerve terminals were located between 30 and 70%. This area may correspond to the cricoid cartilage of the sixth cervical vertebra. CONCLUSION: Most intramuscular nerve terminals can be found in the middle and distal portions of the levator scapulae muscle. Our findings improve our understanding of the intramuscular nerve distribution of the levator scapulae muscle and will aid in pain management in clinical practice.

Intramuscular neural distribution of the obturator internus muscle regarding injective treatment.

INTRODUCTION: The obturator internus muscle is frequently targeted for injective treatments such as botulinum toxin injections in the management of pain syndromes. However, there are controversies over injective method delivering injection to the muscle. METHOD: A method called modified Sihler's method was used to stain the OI muscle in 16 specimens to reveal the intramuscular neural distribution of the muscle. RESULT: The greatest intramuscular neural distribution was located on the 2/10-4/10 of the muscle in the medial edge of the obturator foramen (0/0) to the greater trochanter of the femur (10/10). CONCLUSION: The result suggests that botulinum neurotoxin should be delivered in the intrapelvic portion of the obturator internus muscle. As most of the extrapelvic portion of the obturator muscle is composed of a tendinous portion, it should be considered unsuitable as an injection site by medical professionals.

Guidance in botulinum neurotoxin injection for lower extremity spasticity: Sihler's staining technique.

Spasticity is a motor disease characterized by a velocity-dependent acceleration in muscle tone or tonic stretch reflexes linked to hypertonia. Lower limb spasticity has been successfully treated with botulinum neurotoxin; however, the injection sites have not been generalized. Sihler's stain has been used to visualize intramuscular nerve distribution to guide botulinum neurotoxin injection. Sihler staining is a whole-mount nerve staining technique that allows visualization of nerve distribution and mapping of entire nerve supply patterns in skeletal muscle with hematoxylin-stained myelinated nerve fibers. This study reviewed and summarized previous lower extremity spasticity studies to determine the ideal injection site for botulinum neurotoxin.

Botulinum neurotoxin injection in the deltoid muscle: application to cosmetic shoulder contouring.

BACKGROUND AND OBJECTIVES: This study describes the intramuscular nerve branching of the deltoid muscle in relation to shoulder surface anatomy, with the aim of providing essential information regarding the most appropriate sites for botulinum neurotoxin injection during shoulder line contouring. METHODS: The modified Sihler's method was used to stain the deltoid muscles (16 specimens). The intramuscular arborization areas of the specimens were demarcated using the marginal line of the muscle origin and the line connecting the anterior and posterior upper edges of the axillary region. RESULTS: The intramuscular neural distribution of the deltoid muscle had the greatest arborization patterns in the area between the horizontal 1/3 and 2/3 lines of the anterior and posterior deltoid bellies, and 2/3 to axillary line in middle deltoid bellies. The greatest part of the posterior circumflex artery and axillary nerve ran below the areas with the highest aborizations. CONCLUSION: We propose that botulinum neurotoxin injections should be administered in the area between the 1/3 and 2/3 lines of the anterior and posterior deltoid bellies, and 2/3 to axillary line on middle deltoid bellies. Accordingly, clinicians will ensure minimal dose injections and fewer adverse effects of the botulinum neurotoxin injection. Deltoid intramuscular injections, such as vaccines and trigger point injections, should ideally be adapted according to our results.

Sonoanatomy of the platysmal bands: What causes the platysmal band?

BACKGROUND: The platysmal band is created by the platysma muscle, a thin superficial muscle that covers the entire neck and the lower part of the face. The platysmal band appears at the anterior and posterior borders of the muscle. To date, no definite pathophysiology has been established. Here, we observed a lack of knowledge of the anatomy of the platysma muscle using ultrasonography in this study. METHODS: We conducted a descriptive, prospective study observing the platysmal band in resting and contraction states to reveal muscle changes. Twenty-four participants (aged 23-57 years) with anterior and posterior neck bands underwent ultrasonography in resting and contracted states. Ten cadavers were studied aged 67-85 years to measure the thickness of the platysma muscle at 12 points: horizontally (medial, middle, lateral) and vertically (inferior mandibular margin, hyoid bone, cricoid cartilage, superior margin of clavicle). RESULTS: The anterior and posterior borders of the platysma muscle were thicker than the middle of the platysma muscle when in a contracted state, and the muscle also had a convex shape when contracted. The thickness of the platysma muscle was not significantly different over 12 points in the resting state. During contraction, the platysma muscles contracted in the medial and lateral margins of the muscle, which was more significant in the posterior bands. CONCLUSION: The anterior and posterior platysmal bands are related to muscle thickness during contraction. These observations support the change in platysmal band treatment only at the anterior and posterior border of the muscle.

A standardized protocol for needle placement in the infraspinatus muscle: an anatomical perspective.

PURPOSE: This study aimed to evaluate the morphology of the three parts of the infraspinatus muscle based on surface landmarks for precise and effective access, and to propose the most effective fine-wire electrode insertion technique and sites. METHODS: Fifteen Asian fresh cadavers were used. We investigated the probability of the presence of the superior, middle, and inferior parts in each infraspinatus muscle based on surface landmarks. Based on the positional characteristics of the muscle, we determined the needle insertion method and confirmed its effectiveness by dissection. RESULTS: The superior part was mostly observed near the spine of the scapula. The middle part was broadly observed within the infraspinous fossa. The inferior part showed variable location within the infraspinous fossa. The injection accuracy of the superior, middle, and inferior parts in the infraspinatus muscle was 95.8%, 100%, and 91.7%, respectively. Targeting the superior and middle parts for injection of the infraspinatus muscle is relatively more straightforward than targeting the inferior part. Targeting the inferior part of the infraspinatus muscle in this study was more challenging than targeting the superior and middle parts. CONCLUSION: Needling for electromyography should be performed with special care to avoid unintended muscle parts, which could lead to inaccurate data acquisition and affect the conclusions about muscle function.

Collateral and permeability imaging derived from dynamic contrast material-enhanced MR angiography in prediction of PH 2 hemorrhagic transformation after acute ischemic stroke: a pilot study.

PURPOSE: To evaluate the role of collateral and permeability imaging derived from dynamic contrast material-enhanced magnetic resonance angiography to predict PH 2 hemorrhagic transformation in acute ischemic stroke. METHODS: The secondary analysis of a published data from participants with acute ischemic stroke. The multiphase collateral map and permeability imaging were generated by using dynamic signals from dynamic contrast material-enhanced magnetic resonance angiography obtained at admission. To identify independent predictors of PH 2 hemorrhagic transformation, age, sex, risk factors, baseline National Institutes of Health Stoke Scale (NIHSS) score, baseline DWI lesion volume, collateral-perfusion status, mode of treatment, and successful early reperfusion were evaluated with multiple logistic regression analyses and the significance of permeability imaging in prediction of PH 2 hemorrhagic transformation was evaluated by subgroup analysis. RESULTS: In 115 participants, including 70 males (mean (SD) age, 69 (12) years), PH 2 hemorrhagic transformation occurred in 6 participants with very poor collateral-perfusion status (MAC 0). MAC 0 (OR, 0.06; 95% CI, 0.01, 0.74; P = .03) was independently associated with PH 2 hemorrhagic transformation. In 22 participants with MAC 0, the permeable signal on Kep permeability imaging was the only significant characteristic associated with PH 2 hemorrhagic transformation (P = .009). The specificity of Kep permeability imaging was 93.8% (95% confidence interval: 69.8, 99.8) in predicting PH 2 hemorrhagic transformation. CONCLUSION: Individual-based prediction of PH 2 hemorrhagic transformation in patients with acute ischemic stroke may be possible with multiphase collateral map and permeability imaging derived from dynamic contrast material-enhanced magnetic resonance angiography.

Usefulness of a long sheath in ureteral catheterization after failure of antegrade ureteral stent placement using a short sheath.

BACKGROUND: When antegrade ureteral intervention fails due to severe ureteral stricture or tortuosity, a longer sheath can be used to facilitate ureteral catheterization. PURPOSE: To evaluate the feasibility and effectiveness of the use of a long sheath in antegrade ureteral stent placement after failure of antegrade ureteral stent placement using a short sheath. MATERIAL AND METHODS: Among 1284 procedures in 934 patients who received ureteral stent placement, a long sheath was used after stricture negotiation failure using a short sheath in 57 (4.4%) procedures in 53 patients. The data of these 53 patients were retrospectively reviewed. RESULTS: The most common reasons for long sheath use were failure of balloon catheter (59.6%) or guidewire (29.8%) advancement across the stricture. Technical success, successful stricture negotiation after using a long sheath, was achieved in 50/57 (87.7%) procedures. In two of seven failed procedures, an additional TIPS sheath was used and the technical success rate improved to 91.2% (52/57). The technical success rate was significantly higher in the patients who have failed balloon catheter advancement (97.1%, 33/34) than the patients who have failed guidewire advancement (64.7%, 11/17) (Fisher's exact test, P = 0.004). Self-limiting hematoma occurred in one patient after use of the long sheath and was considered a minor complication. CONCLUSION: Ureteral catheterization using a long sheath is feasible and effective when antegrade ureteral intervention using a short sheath fails. When using a long sheath, the technical success rate was higher when advancing the balloon catheter over the guidewire than when advancing the guidewire through tight stricture.

Effective botulinum neurotoxin injection in treating iliopsoas spasticity.

INTRODUCTION: To detect ideal locations for botulinum toxin (BoNT) injection by exploring the intramuscular nerve arborization of the psoas major and iliacus muscles. METHOD: A modified Sihler's method was performed on the psoas major and iliacus muscles (16 specimens each). Intramuscular nerve arborization was recorded according to the most prominent point of the anterior superior iliac spine (ASIS), the posterior superior iliac spine (PSIS), the lesser trochanter (LT), and the transverse process of the 12th thoracic vertebra. RESULTS: Intramuscular nerve arborization of the psoas major muscle was the largest from 1/5 to 3/5 the distance from the transverse process of the 12th thoracic vertebra to the PSIS, and the tendinous portion of the muscle occupied from 3/5 to 5/5 this distance. In terms of the plane of the ASIS, the PSIS, and the LT, the arborization of the iliacus muscle was the largest from 1/5 to 3/5 the horizontal distance and 0 to 1/3, the distance longitudinally, and from 1/5 to 2/5, the horizontal distance and 1/3 to 2/3, the longitudinal distance. DISCUSSION: These results suggest that an injection of BoNT to the psoas major and iliacus muscle should be applied in specific areas. Additionally, the posterior approach is an ideal method for targeting only the psoas major because the injection point is above the PSIS. However, when treating both the psoas major and iliacus muscles, the proximal anterior approach is an ideal method according to the arborization patterns.

Clinical anatomy considerations on the muscular and vascular components of the midface by ultrasonographic imaging.

The first signs of face aging appear in the midface, so procedures such as botulinum toxin and filler injections are performed there. However, no guidelines based on clinical anatomy describing the muscular and vascular components in vivo have been published. The aim of this research was to describe the depths of the midface muscles and the locations of vessels using ultrasonographic (US) imaging. US was applied at 12 landmarks on the midface in 88 volunteers (49 males and 39 females; 19-36 years) to detect sex differences in the depths of muscles and the locations of the vessels. The depths of the orbicularis oculi (OOc), levator labii superioris alaeque nasi (LLSAN), and zygomaticus minor (Zmi) differed significantly with sex at P7 (p = 0.001) and P8 (p = 0.017), P1 (p = 0.028), and P4 (p = 0.035), respectively. The facial artery, facial vein, angular artery, angular vein, and perforator vessels were found at P9, P2 and P10, P1, P1 and P5, and P8, P11 and P12, respectively. The findings indicate that the depths of the OOc, LLSAN, and Zmi muscles differ between the sexes and that the vessels appear at specific landmarks. This information could help in developing anatomical guidelines for several procedures.

Anatomical guide for botulinum neurotoxin injection: Application to cosmetic shoulder contouring, pain syndromes, and cervical dystonia.

INTRODUCTION: This study proposes an ideal botulinum toxin injection point of the trapezius muscle for shoulder line contouring, pain management, and functional impairment. This study describes the intramuscular nerve branching in the trapezius muscle, providing essential information for botulinum neurotoxin injection. METHOD: A modified Sihler's method was performed on the trapezius muscles (16 specimens). The intramuscular arborization areas were elucidated regarding the external occipital protuberance superiorly, spinous process of the 12th thoracic vertebra inferiorly and acromion of the scapula. RESULT: The intramuscular neural distribution for the superior, middle, and inferior regions of the trapezius muscle had the greatest arborized patterns in the horizontal 1/5-2/5 and vertical 2/10-4/10 sections, the horizontal 1/5-3/5 and vertical 4/10-5/10 sections, and the horizontal 1/5-2/5 and vertical 5/10-7/10 sections, respectively. DISCUSSION: We propose that BoNT treatments should be directed to the horizontal 1/5-2/5 and vertical 2/10-4/10 sections of the superior trapezius, the horizontal 1/5-3/5 and vertical 4/10-5/10 sections of the middle trapezius and the horizontal 1/5-2/5 and vertical 5/10-7/10 sections of the inferior trapezius. Additionally, injective treatment at the horizontal 2/5-3/5 and vertical 2/10-4/10 nerve entry points should be avoided to prevent nerve trunk damage causing paralysis. According to our guidelines, clinicians can ensure minimal dose injections and fewer adverse effects in botulinum neurotoxin injective treatment.

Three-Dimensional Evaluation of the Depressor Anguli Oris and Depressor Labii Inferioris for Botulinum Toxin Injections.

BACKGROUND: Botulinum toxin type A (BoNT-A) injection administered at an inappropriate site or depth can produce an unwanted change in facial animation because the depressor anguli oris (DAO) and depressor labii inferioris (DLI) muscles are partially overlapped. Therefore, simple BoNT-A injection guidelines, based on 3-dimensional (3D) facial anatomic references and landmarks, would be very useful. OBJECTIVES: The aim of this study was to establish novel BoNT-A injection guidelines that include the soft tissue thickness at the lower perioral region. Data were acquired with a 3D scanning system combined with dissections in order to obtain accurate injection sites and depths for the DAO and DLI. METHODS: 3D scans of the facial skin, superficial fat, and facial muscle surface were performed in 45 embalmed cadavers. The thicknesses of the skin and subcutaneous layer were calculated automatically from superimposed images at each of 5 reference points (P) in the perioral region. RESULTS: In every case (100%), P3 and P5 were located in the DLI and DAO areas, respectively (45/45). Therefore, we defined P3 as the "DLI point" and P5 as the "DAO point." The soft tissue thicknesses at the DLI and DAO points were 6.4 [1.7] mm and 6.7 [1.8] mm, respectively. CONCLUSIONS: The P3 and P5 described in this study are effective guidelines that only target the DLI and DAO. Clinicians, specifically, can easily use facial landmarks, such as the cheilion and pupil, to assign the DLI and DAO points without any measurement or palpation of the modiolus.