Skeletal Units Research Articles

Changes of functional units in type IIA craniofacial microsomia before puberty-a preliminary computed tomography study

BackgroundThe natural growth of the mandible in craniofacial microsomia (CFM) remains a topic of considerable debate. This study aims to characterize the mandibular architecture and its natural growth in children with type IIA CFM using functional unit analysis. Materials and methods16 sets CT data of 8 unoperated children with unilateral IIA CFM with an interval ranging from 2 to 6 years (3.4±1.5 years,AVR±SD)were collected. The baseline skeletal units’ discrepancy in size, annual growth, and angular measurements were analyzed. ResultsThe condylar, coronoid, and body units were smaller (reaching 63%, 79%, and 90% of the unaffected side, respectively) while the angular unit was larger on the affected side. The condylar unit on the affected side grew slower than the unaffected side, at about 60% of its rate, and other units showed no statistically significant bilateral differences. The backward rotation angle of the affected body unit (BUA) increased from T1 to T2. ConclusionThis preliminary study suggests that the condyle unit is the center of mandible deformity in type IIA CFM and exhibits insufficient growth relative to the unaffected side . Meanwhile, the hemi-mandible on the affected side rotated posteriorly during growth, thus worsening spatial relation. Future studies with larger sample sizes that incorporate clinical assessments are needed to elucidate the progression of CFM.

Association Between Transverse Collapse of the Maxilla and Facial Biotypes by Cone Beam Tomography

Introduction: Skeletal unit growth may be due to epigenetic influence exerted by the functional matrix on the skeleton. Penn analysis is a method used to evaluate tomographically the transverse alterations of the maxilla. Objective: To analyze the association between transverse collapse of the maxilla and facial biotype in patients of the Polyclinic of the Orthodontics Postgraduate Program of the Autonomous University of Baja California, Mexicali campus. Materials and methods: An observational, analytical and cross-sectional study was carried out. The sample consisted of 75 patients who met the inclusion criteria. Initial tomographic studies were used to determine the presence of transverse collapse by means of Penn analysis. Lateral skull teleradiographs were plotted to determine the facial biotype by means of the Vert coefficient of Ricketts' lateral cephalometric analysis. The chi-square test was performed for statistical analysis of the association between the presence of transverse collapse of the maxilla and facial biotypes. Results: No significant results were found between the chi-square values and the p-value for patients with transverse collapse of the maxilla in association with facial biotypes. However, a statistical chi-square value of 4.8422 and a p-value of 0.2777 were obtained for the sample of female patients with transverse collapse of the maxilla. Conclusions: No association was found between the presence of maxillary transverse deficiencies and facial biotypes.

Iron-catalyzed oxosulfonylation of alkynes with small-ring compounds and Na2S2O5 for the synthesis of β-keto sulfones

An efficient and rapid iron-catalyzed oxosulfonylation of alkynes with small-ring compounds and Na2S2O5 for the synthesis of β-keto sulfones has been developed.

Effect of nitrate supplementation on skeletal muscle motor unit activity during isometric blood flow restriction exercise

BackgroundNitrate (NO3−) supplementation has been reported to lower motor unit (MU) firing rate (MUFR) during dynamic resistance exercise; however, its impact on MU activity during isometric and ischemic exercise is unknown.PurposeTo assess the effect of NO3− supplementation on knee extensor MU activities during brief isometric contractions and a 3 min sustained contraction with blood flow restriction (BFR).MethodsSixteen healthy active young adults (six females) completed two trials in a randomized, double-blind, crossover design. Trials were preceded by 5 days of either NO3− (NIT) or placebo (PLA) supplementation. Intramuscular electromyography was used to determine the M. vastus lateralis MU potential (MUP) size, MUFR and near fibre (NF) jiggle (a measure of neuromuscular stability) during brief (20 s) isometric contractions at 25% maximal strength and throughout a 3 min sustained BFR isometric contraction.ResultsPlasma nitrite (NO2−) concentration was elevated after NIT compared to PLA (475 ± 93 vs. 198 ± 46 nmol L−1, p < 0.001). While changes in MUP area, NF jiggle and MUFR were similar between NIT and PLA trials (all p > 0.05), MUP duration was shorter with NIT compared to PLA during brief isometric contractions and the sustained ischemic contraction (p < 0.01). In addition, mean MUP duration, MUP area and NF jiggle increased, and MUFR decreased over the 3 min sustained BFR isometric contraction for both conditions (all p < 0.05).ConclusionsThese findings provide insight into the effect of NO3− supplementation on MUP properties and reveal faster MUP duration after short-term NO3− supplementation which may have positive implications for skeletal muscle contractile performance.

Impact of Cell Seeding Density and Cell Confluence on Human Tissue Engineered Skeletal Muscle.

Tissue engineering methodologies have the potential to treat volumetric muscle loss via the growth of exogenous skeletal muscle grafts from small autogenous muscle biopsies. A significant obstacle preventing the widespread use of engineered skeletal muscle grafts in a clinical setting is the high number of skeletal muscle stem cells, known as satellite cells, required for fabrication of human-sized skeletal muscle tissue. Additionally, there is a lack of work adapting engineered constructs created for animal models into skeletal muscle engineered from a primary human skeletal muscle cell source. For this study, we used scaffold-free tissue-engineered skeletal muscle units (SMUs) to determine the impact of cell seeding density on the ability to fabricate functional human engineered skeletal muscle. Following established protocols, human skeletal muscle isolates were cultured into SMUs at five different cell seeding densities: 1000, 2500, 5000, 10,000, and 25,000 cells/cm2. Following previous human SMU work, SMUs prepared at a cell seeding density of 10,000 cells/cm2 served as controls. Additionally, the impact of cell monolayer confluency on the outcome of human cell-sourced SMU fabrication was investigated at both the 1000 and 10,000 cells/cm2 seeding densities. Light microscopy was used to examine myotube formation and hypertrophy in cell monolayers. After the formation of three-dimensional constructs, SMUs underwent maximum tetanic isometric force production measurements and immunohistochemical staining to examine SMU contractile function and muscle-like structure, respectively. Results indicate that the 25,000 cells/cm2 cell seeding density was detrimental to the contractile function of human cell-sourced SMUs, which had significantly lower maximum tetanic forces compared with SMUs seeded at lower densities. Compared with control, low cell seeding densities (1000-5000 cells/cm2) have no detrimental impact on SMU skeletal muscle growth, maturation, or contractility. Cell cultures seeded at 1000 cells/cm2 and allowed to proliferate to 90-100% confluency before treatment in muscle differentiation media (MDM) resulted in SMUs with greater contractile forces and total muscle structure compared with cell cultures switched to MDM when underconfluent or overconfluent. In conclusion, initial cell seeding density for SMU fabrication can be decreased to as low as 1000 cells/cm2 without negatively impacting SMU muscle-like structure and function. Impact Statement Our research suggests that during the translation of skeletal muscle tissue engineering technologies from animal to human cell sources, initial starting cell seeding density can be significantly lowered without negatively impacting engineered skeletal muscle growth, maturation, or contractile function. Decreasing the initial cell density, and, thus, the muscle biopsy size required to fabricate an engineered human skeletal muscle, increases the potential for the clinical adoption of tissue-engineered based therapies for volumetric muscle loss.

Relationship between Maxillary Sinus Hypoplasia and Maxillary Occlusal Cant: A Cone Beam CT Study

Introduction. Maxillary sinus hypoplasia (MSH) has been reported to cause a cant in the orbital plane. No similar reports exist about the possible impact on the maxilla. The aim of this study was to assess if MSH is associated with maxillary occlusal plane (MOP) cant and if dental or mandibular factors influenced the existence of the MOP cant. Methods. 80 cone beam CT images of subjects with MSH were analyzed for the type of MSH, degree of MOP cant, open or cross bite, mandibular asymmetry, and degenerative joint disease of the temporomandibular joints. The subjects were compared with a control group matched by age and gender. Results. The degree of MOP cant (range 0–5.1°) was not statistically significantly different in unilateral vs. bilateral MSH or between the different types of MSH. The frequency of open bite, crossbite, mandibular asymmetry, or degenerative joint disease in unilateral vs. bilateral MSH or between the different types of MSH was not statistically significantly different. Between the case and control, there was no statistically significant difference in the degree of MOP cant ( 1.3 ± 1.1 ° vs. 1.1 ± 0.9 ° , respectively) or frequency of dental and mandibular factors. There was low positive linear correlation between MOP cant and mandibular symmetry in MSH subjects (Spearman’s rho = 0.23 ) and controls (Spearman’s rho = 0.18 7). Conclusions. The data suggests a view of the alveolar bone as the adaptable skeletal unit to ensure and bridge the functionality between the nasomaxillary complex and TMJ system–two systems with very different function, and therefore largely independent “matrix units.”

Osteoblasts pattern endothelium and somatosensory axons during zebrafish caudal fin organogenesis.

Skeletal elements frequently associate with vasculature and somatosensory nerves, which regulate bone development and homeostasis. However, the deep, internal location of bones in many vertebrates has limited in vivo exploration of the neurovascular-bone relationship. Here, we use the zebrafish caudal fin, an optically accessible organ formed of repeating bony ray skeletal units, to determine the cellular relationship between nerves, bones and endothelium. In adult zebrafish, we establish the presence of somatosensory axons running through the inside of the bony fin rays, juxtaposed with osteoblasts on the inner hemiray surface. During development we show that the caudal fin progresses through sequential stages of endothelial plexus formation, bony ray addition, ray innervation and endothelial remodeling. Surprisingly, the initial stages of fin morphogenesis proceed normally in animals lacking either fin endothelium or somatosensory nerves. Instead, we find that sp7+ osteoblasts are required for endothelial remodeling and somatosensory axon innervation in the developing fin. Overall, this study demonstrates that the proximal neurovascular-bone relationship in the adult caudal fin is established during fin organogenesis and suggests that ray-associated osteoblasts pattern axons and endothelium.

Convergent losses of SCPP genes and ganoid scales among non-teleost actinopterygians.

Various secretory calcium-binding phosphoprotein (SCPP) genes are expressed in the skin and jaw during the formation of bone, teeth, and scales in osteichthyans (bony vertebrates). Among these mineralized skeletal units is the ganoid scale, found in many fossil actinopterygians (ray-finned fish) but confirmed only in Polypteriformes (bichirs, reedfish) and Lepisosteiformes (gars) among extant clades. Here, we examined SCPP genes in the genome of seven non-teleost actinopterygian species that possess or do not possess ganoid scales. As a result, 39-43 SCPP genes were identified in Polypteriformes and Lepisosteiformes, whereas 22-24 SCPP genes were found in Acipenseriformes (sturgeons, paddlefish) and Amiiformes (bowfin). Most of these genes form two clusters in the genome of Polypteriformes, Lepisosteiformes, and Amiiformes, and these two clusters are duplicated in Acipenseriformes. Despite their distant phylogenetic relationship, Polypteriformes and Lepisosteiformes retain many orthologous SCPP genes. These results imply that common ancestors of extant actinopterygians possessed a large repertoire of SCPP genes, and that many SCPP genes were lost independently in Acipenseriformes and Amiiformes. Notably, most SCPP genes originally located in one of the two SCPP gene clusters are retained in Polypteriformes and Lepisosteiformes but were secondarily lost in Acipenseriformes and Amiiformes. In Lepisosteiformes, orthologs of these lost genes show high or detectable expression levels in the skin but not in the jaw. We thus hypothesize that many SCPP genes located in this cluster are involved in the formation of ganoid scales in Polypteriformes and Lepisosteiformes, and that their orthologs and ganoid scales were convergently lost in Acipenseriformes and Amiiformes.

Correlations Between Mandible Condylar Structures and External Ear Deformities in Hemifacial Microsomia With Three-Dimensional Analysis.

This study aimed to explore correlations between mandible and ear deformities and quantitative volumetric relations between condylar structures and external ear in hemifacial microsomia. The authors reconstructed three-dimensional craniofacial models from 212 patients with unilateral hemifacial microsomia (the unaffected side as the controls). Patients were evaluated by Pruzansky-Kaban and Marx classification, and divided into 3 age groups (0-6, 7-12, and >12 years of age). The mandible condylar structures, including condyle and the condylar skeletal unit, were selected (except the classification of the mandibular or ear deformities (M3)). Along with the external ear (except the classification of the mandibular or ear deformities (E4)), their volumes were measured and analyzed. Spearman correlation coefficient analysis was applied. There was a positive correlation between the mandible and ear deformities (r = 0.301, P < 0.001). Either between the condyle and external ear ( P = 0.071-0.493) or between the condylar unit and external ear ( P = 0.080 - 0.488), there were no volumetric relations on the affected side, whereas on the unaffected side were (r = 0.492-0.929 for condyle, r = 0.443-0.929 for the condylar unit, P < 0.05). In most cases, the condylar structures of the classification of the mandibular or ear deformities (M2b) were significantly smaller than the classification of the mandibular or ear deformities (M2a). Results suggested deformities of mandibular condylar structures and ear did not correlate, although deformities of mandible and ear did. The condylar deformity might develop independently from microtia and be more severe within relatively more abnormal temporomandibular joints.

Its What’s on the Inside That Counts: An Effective, Efficient, and Streamlined Method for Quantification of Octocoral Symbiodiniaceae and Chlorophyll

Ocean warming driven bleaching is one of the greatest threats to zooxanthellate cnidarians in the Anthropocene. Bleaching is the loss of Symbiodiniaceae, chlorophyll, or both from zooxanthellate animals. To quantify bleaching and recovery, standardised methods for quantification of Symbiodiniaceae and chlorophyll concentrations have been developed for reef-building scleractinian corals, but no such standard method has been developed for octocorals. For stony corals, quantification of Symbiodiniaceae and chlorophyll concentrations often relies on normalisation to skeletal surface area or unit of biomass [i.e., protein, ash-free dry weight (AFDW)]. Stiff octocorals do not change their volume, as such studies have used volume and surface area to standardise densities, but soft-bodied octocorals can alter their size using water movement within the animal; therefore, Symbiodiniaceae and chlorophyll cannot accurately be measured per unit of surface area and are instead measured in units of Symbiodiniaceae and chlorophyll per μg of host protein or AFDW. Though AFDW is more representative of the full biomass composition than host protein, AFDW is more time and resource intensive. Here, we provide a streamlined methodology to quantify Symbiodiniaceae density, chlorophyll concentration, and protein content in soft-bodied octocorals. This technique uses minimal equipment, does not require freeze-drying or burning samples to obtain ash weight, and is effective for down to 0.2 g wet tissue. Bulk samples can be centrifuged, the Symbiodiniaceae pellet washed, and the supernatant saved for protein analysis. This efficient technique allows for clean, easy to count samples of Symbiodiniaceae with minimal animal protein contamination. Chlorophyll a and c2 extractions occurs at different rates, with chlorophyll a taking 24 h to extract completely at 4°C and chlorophyll c2 taking 48 h. Finally, we found that where necessary, wet weight may be used as a proxy for protein content, but the correlation of protein and wet weight varies by species and protein should be used when possible. Overall, we have created a rapid and accurate method for quantification of bleaching markers in octocorals.

Symmetry and Topology of Twin Boundaries and Five-Fold Twin Boundaries in Soft Crystals.

Heteroclusters constructed by tethering dissimilar nanoclusters using organic linkers resemble lipids and self-assemble into cubosomes, namely, microparticles of soft crystals composed of unique nanochannel lattices with a defined symmetry and topology. The internal porous crystal structures can be accurately characterized using transmission electron microscopy. We herein describe twin boundaries and five-fold twin boundaries in cubosomes with a double-diamond Pn3̅m structure. Our analysis indicates a clear distinction in the conformation of the skeletal unit: a centrosymmetric staggered conformation with point group D3d for the normal skeletal unit and a mirror-symmetric eclipsed one with point group D3h for the skeletal unit on the twin boundary. This symmetry distinction causes the channels to change direction and elongate slightly as they pass through the twin boundary, but the topology is maintained. For cubosomes containing five-fold twin boundaries, one of the channels is in the center of the particles seamlessly connecting the five blocks. Our conclusion is that the two distinct channel systems are still continuous. This fundamental understanding will contribute to the development of soft crystals with defined shapes and special inner nanostructures for advanced applications.

Functional Matrix Hypothesis: A Review of Literature

Craniofacial growth is a complex process. Most of the treatment approaches have been based on the fundamental biological mechanisms involved in the growth and development of craniofacial bones and teeth. The exact mechanism which controls cranio facial growth has been a matter of debate and research for years together. The concept that “forms follow function” was first proposed by Vander Klaaw. Functional matrix hypothesis (F.M.H.) is actually an extension of this concept given by Moss. F.M.H. includes a functional matrix and skeletal units. Capsule is an envelope that contains functional cranial components sandwiched between the covering layers. It acts indirectly and passively and not by resorption or deposition. Functional matrix cranial analysis can be done in the maxilla and mandible. There are some limitations in F.M.H., so F.M.H. revisited is explained later which include 4 theories in it.Genomic and epi-genetic processes are examples of totally different types of causation- Genomic- formal cause and Epigenetic- efficient cause. Individually both are necessary causes, but neither are sufficient causes alone. They provide both the necessary and sufficient causes for the control of morphogenesis.

The Effects of Engineered Skeletal Muscle on Volumetric Muscle Loss in The Tibialis Anterior Of Rat After Three Months In Vivo.

Volumetric muscle loss (VML) is traumatic, degenerative, or surgical loss of skeletal muscle that exceeds the regenerative capacity of the remaining muscle, thus resulting in impaired muscle function. In humans, the loss of 30% or more mass of any one muscle will result in permanent structural and functional loss. Current VML repair treatments are limited by donor site morbidity and graft tissue availability, necessitating alternative muscle graft sources. To address this need, our lab has fabricated tissue-engineered skeletal muscle units (SMUs) for implantation into a 30 % VML model in the tibialis anterior (TA) muscle of rat. Previous results showed that after 28 days in vivo, muscle with a 30% VML repaired with our SMUs produced significantly more force than muscle with acute VML. But repair with our SMU did not fully restore muscle force production to that of native muscle. Thus, we hypothesized that more time for in vivo tissue regeneration would allow for greater force recovery. Therefore, the purpose of this study was to examine the long-term (3-month) effects of our SMUs on a 30% VML repair. We also assessed the effects of reinnervation by redirecting a branch of the peroneal nerve to the repair site. Thirty-nine, 2-month old female F344 rats were separated into a nonsurgical control group (n=5) and four surgical experimental groups (VML Only, n=5; VML+Nerve Redirect, n=6; VML+SMU, n=5; VML+SMU+ Nerve Redirect, n=8). Experimental rats were allowed a 3-month recovery period post-surgery before undergoing in situ force testing of the surgical (left) TA. The left TA of the control animals also underwent in situ force testing. Finally, the surgical (left) and contralateral (right) TAs of the experimental animals, as well as the left TA of the control animals, were explanted for histological analysis. Results for specific force showed that while all groups recovered specific forces similar to that of native muscle, the two SMU groups had significantly higher specific forces, on average, compared to the uninjured control group. Histological staining showed small muscle fibers in the repair site in animals that received an SMU. The average cross-sectional area of the native fibers just outside the area of repair (or the equivalent area in control animals) was not significantly different between groups, indicating that hypertrophy of remaining fibers did not contribute to the recovery of force following the VML. Our results suggest that following a 30% VML of the TA muscle, all surgical groups were able to recover TA mass, maximum tetanic and specific force production. Thus, creating a 30% VML in the TA in a rat model is not enough a sufficient VML to produce the sustained VML seen in humans following similar 30% loss of muscle volume.

Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations.

Frogs and toads (Lissamphibia: Anura) show a diversity of locomotor modes that allow them to inhabit a wide range of habitats. The different locomotor modes are likely to be linked to anatomical specializations of the skeleton within the typical frog Bauplan. While such anatomical adaptations of the hind limbs and the pelvic girdle are comparably well understood, the pectoral girdle received much less attention in the past. We tested for locomotor‐mode‐related shape differences in the pectoral girdle bones of 64 anuran species by means of micro‐computed‐tomography‐based geometric morphometrics. The pectoral girdles of selected species were analyzed with regard to the effects of shape differences on muscle moment arms across the shoulder joint and stress dissipation within the coracoid. Phylogenetic relationships, size, and locomotor behavior have an effect on the shape of the pectoral girdle in anurans, but there are differences in the relative impact of these factors between the bones of this skeletal unit. Remarkable shape diversity has been observed within locomotor groups indicating many‐to‐one mapping of form onto function. Significant shape differences have mainly been related to the overall pectoral girdle geometry and the shape of the coracoid. Most prominent shape differences have been found between burrowing and nonburrowing species with headfirst and backward burrowing species significantly differing from one another and from the other locomotor groups. The pectoral girdle shapes of burrowing species have generally larger moment arms for (simulated) humerus retractor muscles across the shoulder joint, which might be an adaptation to the burrowing behavior. The mechanisms of how the moment arms were enlarged differed between species and were associated with differences in the reaction of the coracoid to simulated loading by physiologically relevant forces.

Linking Internal Carbonate Chemistry Regulation and Calcification in Corals Growing at a Mediterranean CO2 Vent

Corals exert a strong biological control over their calcification processes, but there is a lack of knowledge on their capability of long-term acclimatization to ocean acidification. We used a dual geochemical proxy approach to estimate the calcifying fluid pH (pHcf) and carbonate chemistry of a Mediterranean coral (Balanophyllia europaea) naturally growing along a pH gradient (range: pHTS 8.07-7.74). The pHcf derived from skeletal boron isotopic composition (11B) was 0.3-0.6 units above seawater values and homogeneous along the gradient (mean  sem: Site 1 = 8.39  0.03, Site 2 = 8.34  0.03, Site 3 = 8.34  0.02). Also carbonate ion concentration derived from B/Ca was homogeneous (mean  sem (µmol kg-1): Site 1 = 579  34, Site 2 = 541  27, Site 3 = 568  30) regardless of seawater pH. Furthermore, gross calcification rate (GCR, mass of CaCO3 deposited on the skeletal unit area per unit of time), estimated by a “bio-inorganic model” (IpHRAC), was homogeneous with decreasing pH. The homogeneous GCR, internal pH and carbonate chemistry confirm that the features of the ‘building blocks’ – the fundamental structural components - produced by the biomineralization process were substantially unaffected by increased acidification. Furthermore, the pH up-regulation observed in this study could potentially explain the previous hypothesis that less ‘building blocks’ are produced with increasing acidification ultimately leading to increased skeletal porosity and to reduced net calcification rate obtained by including the total volume of the pore space. In fact, assuming that the available energy at the three sites is the same, this energy at the low pH sites could be partitioned among fewer calicoblastic cells that consume more energy given the larger difference between external and internal pH compared to the control, leading to the production of less building blocks (i.e., formation of pores inside the skeleton structure, determining increased porosity). However, we cannot exclude that also dissolution may play a role in increasing porosity. Thus, the ability of scleractinian corals to maintain elevated pHcf relative to ambient seawater might not always be sufficient to counteract declines in net calcification under ocean acidification scenarios.

Volumetric characteristics of prognathic mandible revealed by skeletal unit analysis

The purpose of this study was to evaluate the skeletal units of a normal mandible (class I) and a prognathic mandible (class III), to compare the groups, and to investigate the key functional unit responsible for mandibular prognathism. Hemi-mandibles of 101 cases were evaluated by cone-beam computed tomography. Of these, 50 cases had Class I and 51 had Class III mandibles. The length, volume, and volume/length ratio of each skeletal unit were measured. The ratios of the condyle, body unit, and sum of the hemi-mandible between Class I and Class III showed statistically significant results (P<0.05). However, the ratios of angle, coronoid, and symphysis units did not show any statistical significance on comparison. Dependent on gender, in males the ratio of the condyle of the hemi-mandible showed statistically significant results (P<0.05). Meanwhile in females the ratio of the body and sum of the hemi-mandible showed statistically significant results (P<0.05). Accordingly, the mandibular body and condylar units are thinner in mandibular prognathism. On the basis of the functional matrix theory to determine the aetiology of mandibular prognathism, the key skeletal units are the body and condylar units.

Palladium-Mediated Oxidative Annulation of δ-Indolyl-α,β-Unsaturated Compounds toward the Synthesis of Cyclopenta[ b]indoles and Heterogeneous Hydrogenation To Access Fused Indolines.

The cyclopenta[ b]indole moiety represents a key skeletal unit in several natural and synthetic compounds that exhibit diverse biological properties. We described herein a two-step sequence for synthesizing cyclopenta[ b]indoles with great structural diversity in overall yields up to 37%. The key step was a palladium-catalyzed oxidative annulation of 3-alkylindoles (Fujiwara-Moritani reaction). The obtained cyclopenta[ b]indoles were used as substrates in heterogeneous hydrogenation reactions to afford new fused indolines in moderate yields. An acid-catalyzed intramolecular cyclization of three such indolines gave tetracyclic lactams in 89, 90, and 61% yields.

Relapse tendency after BSSO surgery differs between 2D and 3D measurements: A validation study

Bilateral sagittal split ramus osteotomy (BSSO) surgery is used to correct various dento-skeletal deformities. Clinical outcomes are critically dependent on accurate and proper positioning of skeletal units created by BSSO. Monitoring skeletal changes postoperatively is a major part of follow-up. Between January 2015 and December 2015, 24 patients underwent BSSO surgery without any other segmental osteotomy (mean age, 29.9 ± 14.2 [range, 17–67] years; 18 females). Cephalometric X-rays and cone-beam computed tomography scans were performed 6 weeks and 12 months postoperatively. We compared the position displacement at three mandibular points at both postoperative time points using 2- and 3-dimensional analysis separately and examined the relationship between these methods. Horizontally in at least in 14/24 patients, the difference between 2-dimensional and 3-dimensional measurements was >1 mm. Vertically in at least in 16/24 patients, the difference between 2-dimensional and 3-dimensional measurements was >1 mm. A scatter plot with orthogonal regression indicated the relationships between the 2-dimensional measurement and the corresponding 3-dimensional measurement in the horizontal and vertical directions. Skeletal relapse with 2-dimensional-measurements differed significantly from the 3-dimensional measurements. There was no evidence of a relationship between the two types of measurements regarding the direction and the location of the landmarks.

Structural comparison of hemifacial microsomia mandible in different age groups by three-dimensional skeletal unit analysis

PurposeThe goal of this study was to understand the three-dimensional (3D) structural characteristics of hemifacial microsomia (HFM) mandible in terms of skeletal units, especially to locate the underdeveloped skeletal regions for treatment. Another goal was to compare the HFM structure of different age groups to understand growth potential relevant to treatment scheduling. Materials and methodsWe reconstructed 3D mandibles from computed tomographic images of French and Korean patients with HFM (N = 28; group II) and normal subjects (N = 27; group I). Each mandible was classified by Pruzansky's HFM types I, II and III, and by age group (child, adolescent, and adult). The mandible was divided into skeletal units, and geometrical representation by skeletal unit line was performed, including the condylar, body, coronoid, and angular units. Their length and angulations were measured and statistically analyzed. ResultsThe results showed that the affected condylar unit in type II HFM and the condylar/coronoid unit in type III were smaller in young age groups than were other units. The angulation between the skeletal units in type II, though not type III, tended toward normalcy with age, but not to the normal degree of angulations in group I. ConclusionOur study shows the major involvement of condylar unit and minor involvement of body unit for HFM, improving with age in type II. The mandibular skeletal unit analysis seems to be a useful tool for individualized diagnosis, allowing identification of the major etiopathogenic area and treatment planning, including a simulation to set up a regimen for successful reconstruction of HFM.

Skeletal unit construction of rat mandible based on the masticatory muscle anatomy and double microcomputed tomography.

This study aimed to divide the mandible into skeletal units based on three-dimensional (3D) muscular anatomy with microcomputed tomography (micro-CT) of Sprague-Dawley rat. Five normal rats were micro-CT scanned at 12weeks of age before and after contrast enhancements for the masticatory muscles. Three-dimensional reconstruction of the mandible was performed from the initial micro-CT images, followed by segmentation of the masticatory muscles using the second enhanced micro-CT data. Bone and muscle models were superimposed based on the teeth and bony structures to evaluate muscular orientation and attachment. The mandible was divided into skeletal units using the bony structures and muscle attachments. The mandibular foramen and mental foramen were adopted as the reference points based on their anatomical and developmental significance. The skeletal units consisted of the condylar, coronoid, angular, body and symphyseal units. Further evaluation of these units in relation to development, growth, and other biology and medicine will be helpful in elucidating their biological identities.