Quantitative assessment of oral orbicular muscle deformation after cleft lip reconstruction: an ultrasound elastography study

A Novel Rat Model for Muscle Regeneration and Fibrosis Studies in Surgical Lip Repair

OBJECTIVE

Lip muscle undergoes suboptimal regeneration after surgical repair, but the mechanism underlying this observation remains obscure. This study provided a rat model to investigate lip muscle regeneration after surgical intervention.

DESIGN

This work provided a detailed description of the rat orbicularis oris muscle anatomy, and a surgically injured model was established based on the muscle anatomy.

MAIN OUTCOME MEASURES

Morphological and histological features of the rat orbicularis oris muscle were characterized. The processes of myogenesis and fibrogenesis were examined between the untreated and surgically injured groups.

RESULTS

Rat orbicularis oris muscle is encapsulated by the vermilion and oral mucosa. Although it remains a thin layer of flat muscle with tight myocutaneous and myomucosal junctions, if accessed properly, the rat orbicularis oris muscle could be isolated as a cylindrical muscle bundle with considerable size, facilitating further surgical manipulations of the muscle fibers. Muscles in steady state and after surgical intervention demonstrated distinct molecular features in the myogenesis and fibrogenesis processes, which were quantifiable in tissue section analysis.

CONCLUSION

The orbicularis oris muscle dissection procedures and injury model provided in this work clarify the rat lip muscle anatomy. The injury model offered a platform to analyze the effects of surgical interventions commonly used in lip repair on orbicularis oris muscle regeneration.

The Effectiveness of Plasma Skin Regeneration (PSR) in the Treatment of Chronic Cleft Lip Scars in an Adult Syrian Sample: A Cohort Study on a Novel Technique

Objectives The current study aimed to evaluate the effectiveness of plasma skin regeneration (PSR) in the treatment of cleft lip scars in cleft lip patients.  Materials and methods Twenty patients, 10 females and 10 males, with a mean age of 19 years and who had a cleft lip scar, were included in the current study. All patients were treated with a plasma skin regeneration pen device in one treatment session. The thickness, relief, and pliability of the scars were assessed by external observers using a 10-point numeric rating scale (NRS). Results The thickness, relief, and pliability of the scar were significantly improved according to the observers' opinions (51.67%, 50.25%, and 46.33%, respectively). Conclusions Within the limits of this study, the PSR appeared to be safe and effective for treating cleft lip scars with minimal complications.

[Finite element analysis of the comprehensive impact of scar and maxillary expansion combined with protraction on the development of maxilla with cleft lip and palate after repair operation]

OBJECTIVE

To study the comprehensive impact of scar and maxillary expansion combined with protraction on the development of maxilla with cleft lip and palate after repair operation.

METHODS

In the original finite element model of the maxilla with cleft palate, a finite element model of the maxilla with cleft lip and palate was established by using Boolean operation in ANSYS. Scar force after cleft lip and palate repair and maxillary expansion force combined with protraction were added simultaneously to process the stress analysis.

RESULTS

Maxillary deformation occurred in the three-dimensional direction. The comparison of displacements was as follows: X-axis>Z-axis>Y-axis.

CONCLUSIONS

Maxillary growth is significantly inhibited in the three-dimensional direction under the comprehensive impact of scar and maxillary expansion combined with protraction after repair operation, especially transverse and sagittal growth.

Quantitative evaluation of elasticity of lower orbicularis oris muscle during the lip closing measurement using sonographic elastography

BACKGROUND

Lip closing functions have never been evaluated from the viewpoint of elastic properties.

OBJECTIVES

The purpose of the present study was to investigate the behavior of the lower orbicularis oris muscle during a button-pull exercise to measure lip closing force and quantitatively evaluate its elastic properties using sonographic elastography.

METHODS

Appropriate compression loads for elastography were randomly measured on one of three types of acoustic couplers on three examiners. Compression tests were performed on three types of acoustic couplers within the appropriate compression load. Using the acoustic coupler with the lowest elastic modulus, the strain ratio of the lower orbicularis oris muscle during lip closing was measured, and elastography was performed on six males under tension loads of 0-8 N.

RESULTS

The intraclass correlation coefficient (1, 3) for the tension load of 0 N was 0.81. Elastography showed that the strain ratio values increased significantly (p < 0.05) as the tension load increased.

CONCLUSIONS

Combining the data obtained from lip closing test devices and sonographic elastography enabled the muscle performance to be evaluated objectively and accurately.

Botulinum toxin type A as a novel method of preventing cleft lip scar hypertrophy-A literature review

BACKGROUND

Cleft lip is a congenital development defect. Primary cleft lip repair leads to cleft scar formation. The resulting scar often undergoes hypertrophy, which negatively affects the facial esthetics, function, and patient's mental health. One of the methods used in scar therapy described in recent years is botulinum toxin injections The aim of this work is to present current knowledge about the impact of botulinum toxin A on cleft lip scar appearance and its effect on scar hypertrophy.

METHODS

The literature search was conducted in the English language via the PubMed and Google Scholar databases.

RESULTS

The results show injections seem to be a promising method in cleft lip scar management. However, future studies, especially randomized controlled trials, are necessary to assess the effect of BoNT-A compared with placebo and to determine the optimal dosages and injection schemes for BoNT-A treatment in cleft lip patients.

Application of Real-time Elastography Ultrasound in the Diagnosis of Axillary Lymph Node Metastasis in Breast Cancer Patients

The pathological status of axillary lymph nodes (ALN) plays a critical role in the staging and treatment of patients with breast cancer. Therefore, differential diagnosis of metastatic ALN is highly desirable in the clinic. We used real-time elastography (RTE) and gray-scale ultrasound to generate a new scoring system for determining ALN status and estimate their performance of this system. Ninety-seven ALNs were examined by both gray-scale ultrasound and RTE. The performance of gray-scale ultrasound was evaluated by the sum of scores according to its features. RTE images were determined by a modulated scoring system based on the percentage and distribution of hypoechoic cortex regions in the ALNs. Strain ratio was also calculated. Diagnostic performance was obtained by receiver operating characteristic curve analysis with pathologic findings used as the reference standard. The sensitivity, specificity and accuracy were 92%, 73% and 83%, respectively, for gray-scale ultrasound; 78%, 93%, 86%, respectively, for RTE; 88%, 96% and 92%, respectively, for the combined evaluation (AUC = 0.963), and 87%, 76% and 81%, respectively, for strain ratio. Gray-scale ultrasonography had a better sensitivity than RTE (92% vs 78%, P = 0.039), while the specificity for RTE was superior to that of gray-scale ultrasonography (93% vs 73%, P = 0.012). In conclusion, RTE showed a high specificity for evaluating the ALN status and may improve the diagnostic accuracy when combined with gray-scale ultrasound.

Permanent maxillary central incisor and first molar rotations in the mixed dentition in repaired complete unilateral cleft lip and palate and their relationship with absence of teeth in their vicinity

OBJECTIVES

To describe qualitatively and quantitatively the directions and magnitudes of rotations of permanent maxillary central incisors and first molars in the mixed dentition in repaired complete unilateral cleft lip and palate (UCLP) and study their associations with absence of teeth in their vicinity.

MATERIALS AND METHODS

Dental casts and orthodontic records taken prior to orthodontic preparation for alveolar bone grafting of 74 children with repaired UCLP (53 male, 21 female; aged 8.9 ± 1.0 years) were studied. Directions and magnitudes of permanent maxillary central incisor and first molar rotations were recorded. Tooth absence was confirmed from longitudinal radiographic records. Incisor and molar rotations were analyzed in relation to the absence of teeth in their vicinity.

RESULTS

Distolabial rotation of the permanent maxillary central incisor was noted in 77.14% on the cleft side, while distopalatal rotation was noted in 82.19% on the noncleft side. Incisor rotation was greater when a permanent tooth was present distal to the cleft side central incisor, in the greater segment. The permanent maxillary first molar showed mesiopalatal rotation, which was greater on the cleft side and when there was absence of one or more teeth in the buccal segment.

CONCLUSIONS

Presence and absence of teeth were associated with the severity of incisor and molar rotations in UCLP. Crowding of anterior teeth in the greater segment was associated with a greater magnitude of rotation of the cleft side permanent central incisor. Absence of one or more buccal segment teeth was associated with greater magnitude of rotation of the molar.

Quantitative assessment of healthy and reconstructed cleft lip using ultrasonography

Purpose:

This study is conducted to investigate the feasibility of echographic imaging of tissue thickness of healthy and reconstructed cleft lip.

Design:

Prospective study.

Materials and Methods:

The study was conducted in SDM Craniofacial Unit, Dharwad and was approved by Local Institutional Review Board. A total of 30 patients, age group ranging from 4 to 25 years, of which 15 postoperative unilateral cleft lip constituted the test group. The remaining 15 with no cleft deformities, no gross facial asymmetry, constituted the control group. The thickness of the mucosa, submucosa, muscle and full thickness of the upper lip were measured with the transversal images using ultrasonography at midpoint of philtrum, right and left side philtral ridges and vermillion border, at 1, 3, 6 months interval.

Results:

There was an increase in muscle thickness at the vermillion border (mean = 6.9 mm) and philtral ridge (5.9 mm). Equal muscle thickness were found between the normal and test group at 6 months follow-up in a relaxed position, which was statistically significant (P = 0.0404).

Conclusion:

Quantitative assessment of thickness and echo levels of various lip tissues are done with proper echographic calibration. Diagnostic potentials of this method for noninvasive evaluation of cleft lip reconstructions were achieved by this study.

Electrophysiological method to examine muscle fiber architecture in the upper lip in cleft-lip patients

OBJECTIVES

The upper lip's musculature comprises several muscle fiber groups with different spatial orientations for various lip movements. In the past, it has not been possible to describe these various groups and their motor units in detail with traditional methods of electromyography (EMG). The purpose of this investigation was to create a viable method for studying the architecture of upper-lip muscle fibers in patients with surgically closed cleft lip by refining the design of a flexible electrode array for multichannel EMG.

METHODS

Calibrated perioral photographs of 36 adult subjects were used to determine the basic geometry of an electrode array for use on different facial shapes. A total of 256 chloride silver electrodes, 1 mm in diameter, were distributed over this geometry to form a grid with interelectrode distances of 2.5 mm. Technical implementation of the electrode array was based on a modified technique used for flexible printed circuit boards. A double-sided adhesive tape with perforations was used to apply the array to the skin in the upper-lip area. Surface EMG signals were recorded while the subjects were performing various lip movements and exerting specific lip forces. The latter were recorded with a specially developed transducer.

RESULTS

Despite an extremely dense grid of electrodes associated with downsized contacts, the electrode array could be precisely applied to the perforated adhesive tape. The electrode array remained firmly attached to the skin even during extensive lip movements. The recorded EMG signals offered high baseline stability and a strong signal-to-noise ratio, thus, allowing us to extract individual motor unit action potentials (MUAPs). Spatiotemporal tracking of MUAPs succeeded in demonstrating the course of muscle fibers belonging to individual motor units. Pilot measurements taken on subjects with surgically closed unilateral cleft lip revealed an asymmetric distribution of muscle activity surrounding the closed cleft-lip segments.

CONCLUSION

Our refined noninvasive electrophysiological method is capable of providing detailed information about muscle fiber architecture and the position, size, and organization of motor units in the lip area. It is thus feasible to conduct further studies to analyze differences in muscle morphology and motor control between surgically treated cleft-lip patients and noncleft individuals.

Myogenic capacity of muscle progenitor cells from head and limb muscles

The restoration of muscles in the soft palate of patients with cleft lip and/or palate is accompanied by fibrosis, which leads to speech and feeding problems. Treatment strategies that improve muscle regeneration have only been tested in limb muscles. Therefore, in the present study the myogenic potential of muscle progenitor cells (MPCs) isolated from head muscles was compared with that of limb muscles. Muscle progenitor cells were isolated from the head muscles and limb muscles of rats and cultured. The proliferation of MPCs was analysed by DNA quantification. The differentiation capacity was analysed by quantifying the numbers of fused cells, and by measuring the mRNA levels of differentiation markers. Muscle progenitor cells were stained to quantify the expression of paired box protein Pax 7 (Pax-7), myoblast determination protein 1 (MyoD), and myogenin. Proliferation was similar in the head MPCs and the limb MPCs. Differentiating head and limb MPCs showed a comparable number of fused cells and mRNA expression levels of myosin-1 (Myh1), myosin-3 (Myh3), and myosin-4 (Myh4). During proliferation and differentiation, the number of Pax-7(+), MyoD(+), and myogenin(+) cells in head and limb MPCs was equal. It was concluded that head and limb MPCs show similar myogenic capacities in vitro. Therefore, in vivo myogenic differences between those muscles might rely on the local microenvironment. Thus, regenerative strategies for limb muscles might also be used for head muscles.