Prevention of Exposure Keratopathy in the Intensive Care Unit: Evaluation of an EMR-Based Lubrication Order Protocol for Ventilated Patients.

Purpose In this pilot study, we aimed to investigate the efficacy of an electronic medical record (EMR) order set for lubricating ointment (four times daily) in the prevention of exposure keratopathy in ventilated patients in the intensive care unit (ICU) at the University of Utah. We attempted to capture the magnitude of morbidity, cost, and care burden in ventilated patients, as well as the utility of a systematic EMR-based preventative lubrication protocol in the ICU setting. Methods After implementation of the order set, a retrospective chart review was performed to capture all ventilated ICU patients pre- and postintervention. Three separate study periods were used: (1) Six months prior to coronavirus disease 2019 (COVID-19) and prior to the ocular lubrication intervention; (2) the subsequent 6-month period including COVID-19 patients but prior to any intervention; and (3) the subsequent 6-month period postintervention, including COVID-19 patients. The primary endpoint of ointment use per day was analyzed with a Poisson regression model. Secondary endpoints including rates of ophthalmologic consultation and exposure keratopathy were compared with Fisher's exact test. A poststudy survey of ICU nurses was included. Results A total of 974 ventilated patients were included in the analysis. Ointment use per day increased by 155% (95% confidence interval [CI] 132-183%, p < 0.001) following the intervention. Rates also increased 80% (95% CI 63-99%, p < 0.001) during the COVID-19 study period but prior to intervention. The percentage of ventilated patients requiring a dilated eye exam for any indication was 3.2, 4, and 3.7% in each of the study periods, respectively. There was an overall down trend in the rate of exposure keratopathy which was diagnosed in 33.3, 20, and 8.3% of those receiving ophthalmologic consultation, though these rates were not statistically significant. Conclusion These preliminary data show a statistically significant increase in the rates of lubrication in mechanically ventilated patients using an EMR-based order set in the ICU setting. There was no statistically significant decrease in the rates of exposure keratopathy. Our preventative protocol with lubrication ointment was of minimal cost burden to the ICU. Further longitudinal and multicenter studies are needed to better assess the efficacy of such a protocol.

Shh Plays an Inhibitory Role in Cusp Patterning by Regulation of Sostdc1.

Crown shapes in mammalian teeth vary considerably from species to species, and morphological characters in crown shape have been used to identify species. Cusp pattern is one of the characters in crown shape. In the processes governing the formation of cusp pattern, the Shh pathway has been implicated as an important player. Suppression of Shh signaling activity in vitro in explant assays appears to induce supernumerary cusp formation in wild-type tooth germs. However, the in vivo role of Shh signaling in cusp pattern formation and the molecular mechanisms by which Shh regulates cusp patterning are not clear. Here, through in vivo phenotypic analyses of mice in which Shh activity was suppressed and compared with wild-type mice, we characterized differences in the location, number, incidence, and shape of supernumerary cusps in molars at embryonic day 15.5. We found that the distances between cusps were reduced in molars of Shh activity-suppressed mice in vivo. These findings confirm and extend the previous idea that Shh acts as an inhibitor in the reaction-diffusion model for cusp pattern formation by negatively regulating the intercuspal distance. We uncovered a significant reduction of expression level of Sostdc1, which encodes a secreted modulator of Wnt signaling, after suppression of Shh activity. The supernumerary cusp formation in Sostdc1-/- mice and compound Sostdc1 and Lrp mutant mice indicates a strong association between Wnt and Shh signaling pathways in cusp patterning. In further support of this idea, there is a high degree of similarity in the supernumerary cusp patterns of mice lacking Sostdc1 or Shh at embryonic day 15.5. These results suggest that Shh plays an inhibitory role in cusp pattern formation by modulating Wnt signaling through the positive regulation of Sostdc1.

Management of sarcomatoid salivary duct carcinoma of the submandibular gland duct with coexisting seropositive human immunodeficiency virus.

BACKGROUND: Sarcomatoid salivary duct carcinoma of the submandibular gland is extremely rare. This paper highlights the impact of surgery and adjuvant radiation therapy on the outcome of this disease. METHODS: A 59-year-old man with human immunodeficiency virus presented with a painless, rapidly growing left neck mass. Biopsy followed by surgical excision of the left submandibular gland revealed sarcomatoid salivary duct carcinoma of the submandibular gland duct with perineural invasion and close margins, for which he underwent adjuvant radiotherapy. Post-operative positron emission tomography and computed tomography revealed no residual or metastatic disease. Pathological analysis of tumour-node-metastasis staging revealed a T2 N0 M0 (stage II) tumour. RESULTS: The patient tolerated his treatment without serious acute or long-term side effects. There was no evidence of disease on comprehensive examination or on positron emission tomography or computed tomography scans at the 4.6-year follow up. CONCLUSION: Surgery followed by adjuvant radiotherapy provided practical locoregional control with acceptable toxicity. Further detailed case reports are warranted to optimise the management of this rare malignancy.

Trimodality approach for ceruminous mucoepidermoid carcinoma of the external auditory canal.

BACKGROUND: Ceruminous mucoepidermoid carcinoma of the external auditory canal is extremely rare. This paper highlights the impact of concurrent chemoradiotherapy on the outcomes of this disease. CASE REPORT: A 47-year-old female presented with a 2-month history of otalgia and a mass in her right ear. Biopsy revealed high grade ceruminous mucoepidermoid carcinoma. She underwent surgical excision of the right external auditory canal and right upper neck dissection. Pathological analysis of tumour-node-metastasis staging revealed a T2 N0 (stage II) tumour. One year later, computed tomography scanning of the temporal bone showed tumour recurrence. Biopsy revealed recurrent ceruminous mucoepidermoid carcinoma. The patient underwent salvage resection. Pathology revealed that the tumour was diffusely invading nearby structures, with perineural invasion, lymphatic spread and extracapsular extension. Pathological analysis of tumour-node-metastasis staging revealed a T3 N1 M0 (recurrent stage IV) tumour. RESULTS: The patient subsequently received concurrent chemoradiotherapy. There was no evidence of disease at 37 months' follow up. CONCLUSION: The trimodality approach, using surgery plus concurrent chemoradiotherapy, provided reasonable loco-regional control with tolerable toxicity. Further detailed case reports are warranted to optimise the management of this rare malignancy.

Trabecular bone ratio of the mandibular condyle according to the presence of teeth: a micro-CT study.

PURPOSE: During mastication, mechanical pressure from the dentition is transmitted to the trabecular bone of the mandible. The occlusal forces, which could thus affect condylar growth, vary with tooth loss, age, and sex. The trabecular bone of the mandibular condyle is denser in dentate subjects than in edentate subjects. However, since the different tooth groups (incisor, premolar, and molar) have different functions, they could exert different effects on the mandibular condyle. The aim of this study was to elucidate the bone quantity of the Korean mandibular condyle according to the presence of teeth using micro-computed tomography (micro-CT), thereby clarifying the influences of tooth presence on the condylar microstructure. METHODS: Thirty-one sides were scanned and reconstructed into a 3D structure using a micro-CT system. The specimen was sectioned vertically, passing through the medial and lateral poles of the mandibular condyle (P0) to enable measurement of the trabecular bone ratio. Likewise, three additional images, parallel with P0, were acquired. Mean and standard deviation values were calculated, and the t test, one-way ANOVA and post hoc analysis were performed to examine the differences among each group, classified according to the presence of teeth and according to sex. RESULTS: The density of the trabecular bone of the mandibular condyle was significantly associated with the presence of the molars, but not the incisors or premolars. There were significant differences between sexes. CONCLUSIONS: The present study has provided data regarding the bone quantity of the trabeculae of the mandibular condyle according to the presence or absence of teeth.

New anatomical insight of the levator labii superioris alaeque nasi and the transverse part of the nasalis.

PURPOSE: The aim of this study was to clarify the morphology and topography of the deep layer of levator labii superioris alaeque nasi muscle (LLSAN) and the transverse part of the nasalis. Anatomical variations in the topographic relationships were also described to understand the function of the LLSAN and the transverse part of the nasalis. METHODS: Anatomical dissections were performed on 40 specimens of embalmed Korean adult cadavers. RESULTS: The LLSAN was divided into two layers, which were superficial and deep in the levator labii superioris muscle (LLS), respectively. The superficial layer of LLSAN descended on the LLS, and the deep layer was located deep in the LLS. The deep layer of LLSAN originated from the superficial layer of LLSAN and the frontal process of the maxilla. It inserted between the levator anguli oris and the orbicularis oris muscles. This transverse part of the nasalis received some muscle fibers from the superficial layer of LLSAN in 90% (36/40) of specimens. The transverse part of the nasalis originated from the maxilla and ascended, passing posterior to the superficial layer of LLSAN in 65% (26/40) of specimens. However, it originated as two muscle bellies from the maxilla and the upper half of the alar facial crease, respectively, in 35% (14/40) of specimens. CONCLUSIONS: These findings will be crucial data to understand the structure and function of the LLSAN and the transverse part of the nasalis.

Extra- and intramuscular nerves distributions of the triceps surae muscle as a basis for muscle resection and botulinum toxin injections.

PURPOSE: To compare the distribution of extramuscular nerve branches with their intramuscular ramifications in the triceps surae muscle, thus providing anatomical substantiation for the topography of muscle resection and botulinum toxin injections. METHODS: Dissection and modified Sihler's staining of 18 whole-mount human cadaveric specimens. RESULTS: The distance between the areas with the highest extramuscular branch density and the area of densest intramuscular arborization in gastrocnemius and soleus muscles is approximately 10% of the calf length. This finding should be taken into consideration during nerve blocking and botulinum toxin injections for the treatment of spasticity. Intramuscular nerve arborization patterns make it possible to outline neuromuscular segments in the gastrocnemius and soleus muscles. CONCLUSIONS: Surgical or therapeutic interventions in areas of high extramuscular and intramuscular nerve density can increase the efficacy and safety of botulinum toxin injections and neurotomy. Intramuscular nerve branching patterns should be taken into consideration during triceps surae resection.

Topographic anatomy of the zygomatic arch and temporal fossa: a cadaveric study.

The zygomatic arch (ZA) is a long, slender and laterally protruding structure of the face that is vulnerable to fracture by various types of trauma. Knowledge of the topographic anatomy of the ZA and temporal fossa is important for appropriate management of ZA problems. Thirty-seven male and 33 female cadavers were investigated in this study. Skin, subcutaneous tissue, fascia and periosteum were completely removed from around the ZA. Several depths and distances were measured based on three landmarks on the ZA: the anterior, middle and posterior portions of its superior margin. The thickness of the ZA was relatively constant in the three portions. The distance from the internal surface of the ZA to the surface of the temporalis muscle was similar in the anterior and middle portions, at about 8mm, and slightly lesser in the posterior portion. The distance from the external surface of the ZA to the temporal bone was the greatest at the anterior portion, and there was a large difference between the anterior and middle portions. The temporalis muscle was the thickest in the anterior portion and the thinnest in the posterior portion. This study suggests that the maximum distance from the internal surface of the ZA to the surface of the temporalis muscle is 8mm, and this should be considered when performing reduction malarplasty on the ZA.

Topography and location of the depressor anguli oris muscle with a reference to the mental foramen.

The labiomandibular fold (LMF) is the area of the face that extends from the mouth corner to the mandibular border, and its prominence tends to increase with age. The LMF can be formed by the medial or lateral border of the depressor anguli oris (DAO). The aim of this study was to demonstrate the topographical anatomy between the DAO and mental foramen, thereby providing critical information for the safest and most effective site at which to inject botulinum toxin type A (BTX-A). Thirty-four hemifaces from Korean adult cadavers were dissected. The maximum width between the medial borders of the bilateral DAO, parallel to the intercheilion horizontal line, was 59.9 +/- 4.6 (mean +/- SD) mm below the lower lip. The minimum width between the medial borders of the attachment of bilateral DAO was 29.7 +/- 4.8 mm at the mandibular border. The mental foramen was located in the middle third from the cheilion to the mandibular border in 28 cases (90.3%), and it was mostly confined within the DAO muscle coverage in 21 cases (67.7%). The buccal branch of the facial nerve entered through the middle third of the lateral border of DAO and then distributed. Concomitantly, the marginal mandibular branch of the facial nerve entered through the lower third of the lateral border of DAO in 17 cases (60.7%). These results represent additional reference data for identifying the position of the mental foramen on the facial skin, and will be useful for providing criteria for the most effective site for injecting BTX-A when treating the LMF.

A study of the secretion mechanism of the sebaceous gland using three-dimensional reconstruction to examine the morphological relationship between the sebaceous gland and the arrector pili muscle in the follicular unit.

BACKGROUND: New models of the structural relationship between the arrector pili (AP) muscle and the sebaceous gland (SG) have been proposed recently. OBJECTIVES: The purpose of the present study was to establish the actual morphological relationship between components of the follicular unit (FU) including the hair follicles, AP muscle and SG using 3D reconstruction of serially sectioned specimens so as to expand previous explanations of the secretory mechanism of the SG and to suggest other possible mechanisms based on newly proposed model. METHODS: Scalp skin specimens were processed using routine histological procedures, with serially sectioned tissue slides being stained with Masson's trichrome. 'Reconstruct' software was used to align, assemble and reconstruct the sections, with observations of the 3D-reconstructed FU [including hair follicles (HFs), AP muscle and SG]. RESULTS: Fifty FUs were reconstructed. The AP muscle was curved and concave as it supported the basal portion of the sebaceous lobules in the perifolliculum. Sebaceous lobules were located between the AP muscle and HFs (angular area) and some sebaceous lobules located in the opposite (counter-angular) area. CONCLUSIONS: We propose that the concave part of the AP muscle pushes up the basal portion of the sebaceous lobule between the HFs and AP muscle during AP muscle contraction and hair erection. In addition, the sebaceous lobule located at the counter-angular position is squeezed by the HF during AP muscle relaxation and hair repositioning. Combined with the previous mechanism of SG secretion, this newly established mechanism based on the 3D structure of the FU will improve our understanding of AP muscle function and SG secretion.

Asymmetry of the palpebral fissure and upper eyelid crease in Koreans.

The purpose of the present study was to quantify the asymmetry of the palpebral fissure (PF) and upper eyelid crease in normal Koreans. Photographs were taken of 273 males and 321 females aged from 20 to 49 years with a standard head position and eyes open. We investigated the presence of asymmetries of the PF inclination (PFI), PF height (PFH), PF width (PFW) and the upper eyelid crease. The criteria for asymmetry were 2 degrees for PFI, 1mm for PFH and 3mm for PFW. The PFH was larger on the right side than on the left side, whereas the PFW was larger on the left than on the right. The prevalence of asymmetry of the PFI, PFH and PFW was 22.3%, 24.2% and 18.3% in males, and 35.8%, 26.5% and 18.7% in females, respectively. In most cases of PF asymmetry, the PFH was larger on the right and the PFW was larger on the left. A left-only upper eyelid crease was more common than a right-only upper eyelid crease in both sexes. The asymmetry of the PF was generally more common in females.

Branching patterns of the arterial branches supplying the middle vascular pedicle of the sternocleidomastoid muscle: a topographic anatomical study with surgical applications for the use of pedicles osteomuscular flaps.

When making a sternocleidomastoid (SCM) osteomuscular flap to include the clavicle and determining the rotation arc of the osteomuscular flap, it is very important to know the location and the origin of the superior thyroid artery and the distribution pattern of the SCM branch. Accordingly, in this study, the 50 SCM muscles and their arteries were dissected in 26 Korean cadavers, and the results were analyzed. The average distances from the origin of the superior thyroid artery to the clavicular and sternal heads of the SCM muscle were 87.6 mm (57.7-123.8 mm) and 131.2 mm (99.7-166.8 mm), respectively. The average distance from the origin of the superior thyroid artery to the SCM branch entering the SCM muscle was 30.1 mm (16.0-37.7 mm). After entering the SCM muscle, the SCM branches of the superior thyroid artery bifurcated into the clavicular and sternal branches at a point located an average of 58.8 mm (28.4-130.4 mm) above the clavicle. The distribution patterns of the superior thyroid artery were classified into six types based on the branching order and the dual supplies to the SCM muscle. Among them, type I in which the laryngeal branch first divided from the superior thyroid artery was the most common case (36%).

Branching patterns of the facial nerve and its communication with the auriculotemporal nerve.

This study examines the anatomic relationships and variability of the facial nerve trunk and its branches, with emphasis on the intraparotid connections between the divisions. Microdissections were performed on 30 Korean half-heads, and the facial nerve trunks and branches were exposed. The average depth of the stylomastoid foramen from the skin surface was 21.0 +/- 3.1 mm, and the distance between the stylomastoid foramen and the bifurcation of the temporofacial (upper) and cervicofacial (lower) divisions was 13.0 +/- 2.8 mm. In 26 of 30 dissections (86.7%), the facial nerve trunk bifurcated into two main divisions, and a trifurcation pattern was seen in the other four cases (13.3%). According to the origin of the buccal branches, we classified the branching patterns of the facial nerve into four categories. In type I (13.8% of cases), the buccal branches arose from the two main divisions of the trunk but not from other branches of the facial nerve. In type II (44.8% of cases), the buccal branches arising from the two main divisions were interconnected with the zygomatic branch. In type III (17.3% of cases), the marginal mandibular branch sent nerve twigs to the buccal branch, which originated from the upper and lower divisions. In type IV (17.3% of cases), the nerve twigs from the zygomatic and marginal mandibular branches merged to the buccal branch arising from the two main divisions. Communications between the facial and auriculotemporal nerve branches, which are known as "communicating auriculotemporal nerves," were observed in 28 of the 30 cases (93.3%). Familiarity with these common variations in the facial anatomy provides useful information for the surgeon in careful dissection, preservation of the facial nerve, and complete removal of the tumors in parotidectomies.

Topographic anatomy of the lingual nerve and variations in communication pattern of the mandibular nerve branches.

We made a thorough observation of the morphology and course of the lingual nerve (LN) and inferior alveolar nerve (IAN) to clarify their topographical relationships in the infratemporal fossa and in the paralingual area. Thirty-two Korean hemi-sectioned heads were dissected macroscopically and microscopically from a clinical viewpoint. On the 32 tracings on the radiograph, the average distance between the retromolar portion and the LN was 7.8 mm, and no case was found where the LN ran above the alveolar crest as passing along the mandibular lingual plate. The bifurcation of the LN and IAN was located around the mandibular notch, inferior to the otic ganglion in 66% of the cases, and a plexiform branching pattern of the mandibular nerve was observed in only two cases. The bifurcation spot of the LN and IAN was located 14.3 mm inferior to the foramen ovale and 16.5 mm superior to the tip of hamulus. Collateral nerve twigs from the LN to the retromolar area were observed in 26 cases (81.2%), with an average of one nerve twig. We observed four types of variations in terms of communication pattern. In four specimens, the mylohyoid nerve passed through the mylohyoid muscle and connected with the LN. In other four specimens, the IAN communicated with the auriculotemporal nerve. We also observed another type of variational communication between the IAN and the nerve to the lateral pterygoid (LPt); this was observed in only one specimen, and it could be predicted that motor innervation from the nerve to the LPt was transmitted via the mental nerve to the depressor anguli oris. Another type was observed where the IAN divided into two branches with the posterior branch being partially entrapped by the LPt muscle fibers.

The discomallear ligament and the anterior ligament of malleus: an anatomic study in human adults and fetuses.

According to some reports, movement of the malleus, resulting from anterior hypertension on the discomallear ligament (DML), could produce aural symptoms related with damage to middle ear structures. The aim of this study was to examine the topographic relationship of the DML and the anterior ligament of malleus (ALM). Four fetuses and 16 adult hemi-sectioned heads were used to determine the anatomic-clinical relevance of DML and ALM in temporomandibular disorder. In fetal specimens, the DML was distinctly interposed between the malleus and the disc of the temporomandibular joint (TMJ), and the ALM had a structure apparently composed of the superior and inferior lamellae, running anteriorly in continuation with the sphenomandibular ligament (SML) through the future petrotympanic fissure (PTF). In all adult specimens, the DML was inserted into the malleus, and it expanded broadly toward the disc and capsular region of the TMJ in a triangular shape and inserted into the disc and capsule of the TMJ. The two-lamellae structure of the ALM was not distinguishable in adult specimens. The overstretched ALM resulted in movement of the malleus in five cases, but similar tension applied to the DML did not cause any movement of the malleus. This result provides an indication of the clinical significance of the ALM, a ligamentous structure continuous with the SML. It is apparent that the ALM has the potential to cause aural symptoms as a result of damage to the middle ear structure.

Topographic anatomy of the mandibular nerve branches distributed on the two heads of the lateral pterygoid.

The purpose of this study was to evaluate the topography of the nerve distribution on the two heads of the lateral pterygoid and to clarify their morphological-functional correlations. The nerve distribution on the lateral pterygoid was studied in 24 hemi-sectioned heads. Both heads of the lateral pterygoid were innervated from the mandibular nerve branches, but with various nerve distribution patterns. The nerves innervating the superior head of the lateral pterygoid originated from the buccal nerve only in 45.8% of cases. In contrast, the nerves innervating the inferior head of the lateral pterygoid originated from both the buccal and mandibular nerve trunk in 58.3% of cases. In the seven distribution categories of the mandibular nerve branches, both the superior and inferior heads of the lateral pterygoid had a common source of nerve innervation in only 20.8% of cases, the buccal nerve. In contrast, in 45.9% of cases, additional nerve twigs from the mandibular nerve trunk were distributed on the inferior head of the lateral pterygoid. In summary, besides the buccal nerve described in anatomy textbooks, the nerve branches that originated directly from the mandibular nerve trunk innervated the lateral pterygoid.

Emerging patterns of the cervical cutaneous nerves in Asians.

Numerous reports exist upon clinical viewpoints of the four cervical cutaneous nerves. Unfortunately, a detailed description of the cervical cutaneous nerves has not yet been published. For this reason, administering effective anaesthesia to a particular nerve branch is difficult. The aim of this study was to clarify the anatomical knowledge about the emerging patterns of the cervical cutaneous nerves in the superficial neck using 35 Korean cadavers (22 male, 13 female). Four cervical cutaneous nerve branches penetrating the fascia of the posterior border of the sternocleidomastoid muscle (SCM) were classified into seven types based on the locations of their nerve emergence. Among these, the separated type (L-G-T-S) was the most frequent (50%). followed by the L-G x T-S type (20.3%), in which the great auricular nerve (G) and the transverse cervical nerve (T) emerged at the same level on the posterior SCM border.

Effects of pH and acetylation on Hg(2+)-induced purple to blue transition in bacteriorhodopsin.

Effects of Hg(2+) ions on the absorption spectrum of bacteriorhodopsin have been measured at different pH values and after acetylation. UV-difference spectroscopy and CD spectra show that Hg(2+)-induced color change is essentially similar to that caused by removal of cations or acidification. The ability of Hg(2+)-induced purple-to-blue transition is pH-dependent and exhibits a maximum at pH 5.5. Acetylation influences the absorption in the same way as Hg(2+) ions and accelerates Hg(2+)-induced purple to blue transition. All these results strongly suggest that the Hg(2+) effect is not a specific binding but just a replacement of intrinsic cations on the membrane surface, where they form a double layer. The composition of the double layer determines the surface pH on the membrane, which affects the color of the bacteriorhodopsin.