The Superficial Fascia System: Anatomical Guideline for Zoning in Liposuction-Assisted Back Contouring.

BACKGROUND: Dorsal contour deformity presents with different manifestations in each part of the back, such as back rolls, iliac crest deposit, and buffalo hump. However, scant current literature exists on the anatomical basis of dorsal contour deformity. The aim of this study was to better understand the anatomical characteristics of the back, and to propose evidence-based zoning principles for liposuction-assisted back contouring. METHODS: A total of 12 fresh cadavers were dissected for observation of each hierarchy in the vertical order (skin to deep fascia) and transverse comparison of the superficial fascial system (SFS) in the scapular-infrascapular-lumbar triangle region. Full-dorsum vectorial sections were used for the study of suprascapular fat deposits. RESULTS: The SFS acts as a bridge connecting all levels of the dorsal subcutaneous tissue. Macroscopically, it is denser in the scapular and lumbar triangle regions and looser in the infrascapular region; microscopically, the ultrastructure of the retinaculum cutis consists of loose interlobular fascia and stiff functional fascia. CONCLUSIONS: The regional variation pattern of the SFS in the back was consistent with observed back contour deformities in Asian female patients. A better understanding of the topographic anatomy of the back applied to evidenced zoning is the basis for improving surgical precision and avoiding dorsal contour deformity.

Abdominal ultrasound in amazonian manatee (Trichechus inunguis) (Natterer, 1883) / Ultrassonografia abdominal em peixe boi amazônico (Trichechus inunguis (Natterer, 1883)

Morphophysiological species researches are fundamental, and diagnostic imaging is an excellent technique, already used in wild animals, with great application, not invasive and provide real-time information of each body. Amazonian manatees are on the list of endangered animals classified in the vulnerable category and knowledge of the normal pattern of ultrasound anatomy of organs and tissues is important for the maintenance and well-being of captive specimens contributing to reintroduction actions. The objective of the study was to standardize the examination technique and describe the ultrasound findings of the liver, gallbladder, stomach, urinary bladder and the subcutaneous tissue of the abdominal region in Trichechus inunguis, in order to contribute with the anatomical and sonographic knowledge and assist in the diagnosis and prognosis diseases. The study used 18 animals to describe the normal sonographic anatomy in the abdominal cavity of the Amazonian manatee. During abdominal scan, it was possible to visualize the features of the liver, gallbladder, stomach, urinary bladder obtained satisfactory results in this study. Therefore, other structures were not primarily identified by the reduced time, lots of fat and gases in intestines of animals.

Pesquisas morfofisiológicas em espécies selvagens são fundamentais, e o diagnóstico por imagem é uma excelente técnica, já usada e com grande aplicação, não invasiva e que fornece informações em tempo real de cada órgão. Peixes-boi-amazônico encontram-se na lista de animais ameaçados de extinção classificados na categoria vulnerável e o conhecimento do padrão normal da anatomia ultrassonográfica de órgãos e tecidos é importante para a manutenção e bem-estar de espécimes em cativeiro contribuindo para ações de reintrodução. O objetivo deste estudo foi padronizar a técnica de exame e descrever os achados ultrassonográficos do fígado, vesícula biliar, estômago, vesícula urinária e o tecido subcutâneo da região abdominal em Trichechus inunguis, de modo a contribuir com o conhecimento anátomo-sonográfico e auxiliar no diagnóstico e prognóstico de doenças. O estudo utilizou 18 animais para descrever a anatomia ultrassonográfica normal na cavidade abdominal de peixe-boi amazônico. Durante a varredura abdominal foi possível visualizar as características dos órgãos obtendo resultados satisfatórios neste estudo, concluindo ser uma técnica eficiente para avaliação de determinados órgãos abdominais em peixe-boi amazônico. Entretanto, outras estruturas não foram identificadas principalmente pelo tempo reduzido, muita gordura e gases nos intestinos dos animais.

In Vivo Analysis of the Superficial and Deep Fascia.

BACKGROUND: Key risk factors for hypertrophic scarring and surgical-site infections are high-tension wounds, fat necrosis, and dead space. All could be prevented by appropriate superficial fascia suturing. However, the as-yet poorly researched anatomy of the superficial fascia should be delineated. This study is the first to quantify the superficial fascia throughout the human body in vivo. METHODS: Ultrasound was used to analyze the superficial and deep fascia of 10 volunteers at 73 points on 11 body regions, including the upper and lower trunk and limbs. Number, thickness and percentage of superficial fascia layers, and deep fascia and dermis thickness, were measured at each point. RESULTS: Seven hundred thirty ultrasound images were analyzed. Body regions varied markedly in terms of subcutaneous variables. Posterior chest had the thickest deep fascia and dermis and the highest average superficial fascia layer thickness [0.6 mm (95 percent CI, 0.6 to 0.7 mm)]. Anterior chest had the most superficial fascia layers [3.7 (95 percent CI, 3.5 to 3.8)]. Posterior and anterior chest had among the highest percentage of superficial fascia. Abdomen and especially gluteus had a low percentage of superficial fascia. Covariate analyses confirmed that posterior and anterior chest generally had higher superficial fascia content than gluteus and abdomen (both p < 0.001). They also showed that the dermis in the posterior and anterior chest increased proportionally to total fascia thickness. CONCLUSIONS: The superficial fascia, deep fascia, and dermis tend to be thick in high-tension areas such as the upper trunk. A site-specific surgical approach is recommended for subcutaneous sutures. CLINICAL RELEVANCE STATEMENT: Understanding the anatomical distribution of the superficial fascia and deep fascia will help surgeons optimize subcutaneous fasciae suturing, thereby potentially reducing the incidence of surgical-site infections and hypertrophic scars.

Anatomy of the Breast Fascial System: A Systematic Review of the Literature.

BACKGROUND: Understanding the anatomy of the fascial and ligamentous structures of the breast is important in both aesthetic and reconstructive breast surgery. Several structures have been identified that play a significant role in the aesthetic qualities and support of the breast warranting consideration in the context of breast reconstruction. METHODS: The authors performed a systematic review of anatomical, clinical, histologic, and radiologic studies that have described, characterized, and named these structures. The authors have summarized and critically appraised prior research to clarify and define the key fascial structures of the breast, their anatomical function, and their clinical significance in aesthetic and reconstructive breast surgery. RESULTS: Through their review, six distinct breast fascial structures were encountered consistently in the literature. The authors have organized them into intraglandular and extraglandular structures and have reviewed their significance in the context of reconstructive breast surgery. CONCLUSIONS: The primary fascial structures of the breast are important anatomical landmarks with numerous clinical applications. Cooper ligaments divide the breast parenchyma. The superficial and deep layers of the superficial fascia encase the breast in a "pocket," condensing into one thickened layer of fascia along the peripheral breast footprint. The inframammary fold supports and defines the inferior pole. The horizontal septum is a reliable neurovascular landmark. The vertical septum is a newly discovered fascial structure. There are certainly clinical implications that have yet to be described because of the relatively limited and disputed information on the fascia of the female breast and, ultimately, more research is warranted.

Melanocyte progenitor cells reside in human subcutaneous adipose tissue.

Based on the assumption that some progenitor cells in an organ might reside in neighboring adipose tissue, we investigated whether melanocyte progenitor cells reside in human subcutaneous adipose tissue. First, we examined the expression of human melanoma black 45 (HMB45) and microphthalmia-associated transcription factor (MITF) in undifferentiated adipose-derived stem cells (ADSCs) by immunostaining, RT-PCR, and western blotting. These two markers were detected in undifferentiated ADSCs, and their expression levels were increased in differentiated ADSCs in melanocyte-specific culture medium. Other melanocytic markers (Melan A, MATP, Mel2, Mel EM, tyrosinase, KIT, and PAX3) were also detected at variable levels in undifferentiated ADSCs, and the expression of some markers was increased during differentiation into the melanocyte lineage. We further showed that ADSCs differentiated in melanocyte-specific culture medium localized in the basal layer and expressed tyrosinase and HMB45 in a 3D epidermal culture system. Melanin deposits were also induced by ultraviolet-light-B (UVB) irradiation. These results demonstrate that melanocyte progenitor cells reside in human subcutaneous adipose tissue and that these cells might have the potential to differentiate into mature melanocytes. Melanocyte and keratinocyte progenitors residing in human subcutaneous tissue can be used for the treatment of skin diseases and skin rejuvenation in the future.

Morphological study of human facial fascia and subcutaneous tissue structure by region through SEM observation.

Fascia of the facial area is contiguous between fat tissues of the subcutaneous and connective tissue layers and does not envelope the muscle surface like other parts of the human body. This structure is called the superficial musculoaponeurotic system (SMAS), which is accepted as an international anatomical terminology. This special structure is commonly used to pull facial muscles during plastic surgeries such as a face lift. Most reports regarding the facial subcutaneous tissue structure including SMAS are in the field of plastic surgery, and only a few studies from a morphological perspective has been reported. Since the facial fascia does not envelope the muscular surface layer which is different from the deep fascia found on the general skeletal muscle surface, a clear definition of this structure has not been established yet. The purpose of this study was to clearly identify the basic morphological structure of the subcutaneous tissue layer containing the SMAS three-dimensionally through a scanning electron microscope using dissected specimen rather than living subjects. Moreover, this study explores structural differences among seven aging facial areas; thereby further clarifying the properties of the structure and add clinical significance and considerations.

Superficial and Deep Facial Anatomy and Its Implications for Rhytidectomy.

The relationship of the skin, the superficial and deep fat compartments, and the ligaments that connect these structures is key to performing any rhytidectomy. In order to successfully mobilize, elevate, and reposition the facial soft tissues, a detailed understanding of facial anatomy is required. This article details the anatomy of the midface and neck that is essential to understanding and performing the face-lift operation.

Multimodal 3D Printing of Phantoms to Simulate Biological Tissue.

Biomedical optical imaging is playing an important role in diagnosis and treatment of various diseases. However, the accuracy and the reproducibility of an optical imaging device are greatly affected by the performance characteristics of its components, the test environment, and the operations. Therefore, it is necessary to calibrate these devices by traceable phantom standards. However, most of the currently available phantoms are homogeneous phantoms that cannot simulate multimodal and dynamic characteristics of biological tissue. Here, we show the fabrication of heterogeneous tissue-simulating phantoms using a production line integrating a spin coating module, a polyjet module, a fused deposition modeling (FDM) module, and an automatic control framework. The structural information and the optical parameters of a "digital optical phantom" are defined in a prototype file, imported to the production line, and fabricated layer-by-layer with sequential switch between different printing modalities. Technical capability of such a production line is exemplified by the automatic printing of skin-simulating phantoms that comprise the epidermis, dermis, subcutaneous tissue, and an embedded tumor.

The Nasolabial Fold: A Micro-Computed Tomography Study.

BACKGROUND: The nasolabial fold is known to be a challenging midface feature for aesthetic physicians. However, the steric conformation of the structures related to the nasolabial fold has remained undefined because the composition and topography of this region are highly intricate. Therefore, this study aimed to clarify the three-dimensional structures of the nasolabial fold using micro-computed tomography and verify their detailed composition by means of histologic observation. METHODS: Twenty-four specimens were collected from the area beside the alae nasi to the area above the oral angle of 12 cadavers (mean age, 80.3 years) bilaterally. Twelve specimens were evaluated by means of phosphotungstic acid contrast staining, and the rest were evaluated by means of histologic staining. All specimens were divided into three regions and analyzed comprehensively. RESULTS: The medial region of the nasolabial fold had dense irregular connective tissue intermingled with muscle fibers; the lateral region of the nasolabial fold had numerous fibrous septa with abundant adipose tissue. The levator labii alaeque nasi and the zygomaticus minor were attached to the medial part of the nasolabial fold, and the fascial septa were intermittently tethered to the dermis, lateral to the nasolabial fold. The extension of the adipose tissue within the fascial septa was limited by the lateral border of the muscle attachment. CONCLUSIONS: Dimensional and distributional alterations of the adipose tissues with senescence could render the nasolabial fold deeper by increasing the depth of the subcutaneous layer, lateral to the fold. Thus, to ameliorate the fold, the adipose tissue, lateral to the fold, or the muscle traction, medial to the fold, should be altered.

Structural Gender Dimorphism and the Biomechanics of the Gluteal Subcutaneous Tissue: Implications for the Pathophysiology of Cellulite.

BACKGROUND: This study was performed to investigate gender differences in gluteal subcutaneous architecture and biomechanics to better understand the pathophysiology underlying the mattress-like appearance of cellulite. METHODS: Ten male and 10 female body donors [mean age, 76 ± 16.47 years (range, 36 to 92 years); mean body mass index, 25.27 ± 6.24 kg/m (range, 16.69 to 40.76 kg/m)] were used to generate full-thickness longitudinal and transverse gluteal slices. In the superficial and deep fatty layers, fat lobule number, height, and width were investigated. The force needed to cause septal breakage between the dermis and superficial fascia was measured using biomechanical testing. RESULTS: Increased age was significantly related to decreased dermal thickness, independent of sex (OR, 0.997, 95 percent CI, 0.996 to 0.998; p < 0.0001). The mean number of subdermal fat lobules was significantly higher in male body donors (10.05 ± 2.3) than in female body donors (7.51 ± 2.7; p = 0.003), indicating more septal connections between the superficial fascia and dermis in men. Female sex and increased body mass index were associated with increased height of superficial fat lobules. The force needed to cause septal breakage in male body donors (38.46 ± 26.3 N) was significantly greater than in female body donors (23.26 ± 10.2 N; p = 0.021). CONCLUSIONS: The interplay of dermal support, septal morphology, and underlying fat architecture contributes to the biomechanical properties of the subdermal junction. This is influenced by sex, age, and body mass index. Cellulite can be understood as an imbalance between containment and extrusion forces at the subdermal junction; aged women with high body mass index have the greatest risk of developing (or worsening of) cellulite.

Inframammary Fold Reconstruction in the Previously Reconstructed Breast: A Comprehensive Review.

The inframammary fold presents a reconstructive challenge once disrupted during total mastectomy or inadequately restored during breast reconstruction. Various methods of recreating the inframammary fold have been proposed, but reports are generally based on small sample sizes and lack long-term analyses and patient-reported outcomes. The authors herein review the literature on inframammary fold anatomy and reconstructive techniques, highlighting the need for more critical analysis of methodology to develop more predictable and durable outcomes.

Anatomy of the Facial Fat Compartments and their Relevance in Aesthetic Surgery.

OBJECTIVE: There has been a significant shift in the understanding of facial anatomy during the last decade. Newer minimally invasive therapeutic options for facial rejuvenation procedures are increasing the need for a better knowledge of anatomy. MATERIAL AND METHODS: The current literature is summarized, analyzed and presented along with the experience of the author for this narrative review, which summarizes the current understanding of the superficial and deep facial fat compartments and their relevance for minimally invasive facial procedures. A schematic facial model was created in order to facilitate a better understanding of the complexity of facial anatomy. RESULTS: The face is arranged in five layers as follows: layer 1: skin; layer 2: subcutaneous fat including the retinacula cutis (composed of fibrous connective tissue); layer 3: superficial musculo-aponeurotic system (SMAS); layer 4: deep fat; and layer 5: periosteum or deep fascia. This arrangement varies between facial regions, especially when the line of ligaments is incorporated into the model. The facial fat compartments are located in layers 2 and 4; each layer has unique characteristics and spatial relationships with the surrounding tissues. CONCLUSIONS: The concept of the layered arrangement is a new way to understand the spatial relationship and functional interplay of the soft tissues of the face. Understanding the layers, the precise location of the superficial and deep facial fat compartments and their boundaries is crucial for the conduct of safe and effective minimally invasive facial procedures.

Aging of the Upper Lip: Part I: A Retrospective Analysis of Metric Changes in Soft Tissue on Magnetic Resonance Imaging.

BACKGROUND: In scientific literature, numerous theories on the mechanism of facial aging can be found. The debate about facial sagging versus deflation is still ongoing. In this study, the metric changes in perioral soft tissue were demonstrated. These data can contribute to a better understanding of physical changes in the aging perioral area. METHODS: Upper lip measurements were performed on cranial magnetic resonance images of 200 Caucasian subjects (100 men and 100 women). The study population was aged between 20 to 30 and 65 to 80 years. The upper lip length and soft-tissue thickness were measured on sagittal and parasagittal section. Cross-section surface area of the upper lip was measured in the sagittal section to represent volume. The data were analyzed with a t test and results were considered significant at p < 0.01. RESULTS: The upper lip in the old age group differed significantly in length (19.24 percent in women and 18.24 percent in men), thickness (up to -40.55 percent in women and -32.74 percent in men), and volume (-20.89 percent in women and -17.40 percent in men). Soft-tissue thickness at the alar nasolabial fold was significantly thinner in the old age group (-25 percent in women and -25.7 percent in men) and showed significantly greater tissue loss than elsewhere in the upper lip (p < 0.001). CONCLUSIONS: These results suggest that the aging perioral area is affected with a combination of soft-tissue lengthening, thinning, and volume loss. The clinical implications of this study on perioral rejuvenating strategies will be explained in part II.

Anatomical Understanding of Target Subcutaneous Tissue Layer for Thinning Procedures in Thoracodorsal Artery Perforator, Superficial Circumflex Iliac Artery Perforator, and Anterolateral Thigh Perforator Flaps.

BACKGROUND: Thinned perforator flaps, reported techniques, and degree of thinning differ by study. This study investigated the anatomy of subcutaneous tissue according to the varying fattiness and identified which component and how much of the subcutaneous tissue layer needed to be excluded to meet target flap thickness using computed tomography. METHODS: Three stratified fattiness groups consisting of 30 donors were formed for thoracodorsal artery perforator, superficial circumflex iliac artery perforator, and anterolateral thigh flaps. Thickness of the superficial fat and the deep fat layers was measured at specific points in donor sites of the three flaps and the proportion of superficial and deep fat layers to exclude to reach the target flap thickness (4, 6, and 8 mm) was calculated. RESULT: The median proportion for the superficial fat layer varies depending on donor fattiness. The estimated percentage reduction of thickness after thin flap elevation along superficial fascia was approximately one-third of the whole layer. A variable proportion of each fat layer needs to be excluded to obtain required thinness and in very thick groups, part of the superficial fat layer must be removed to reach any of the target thicknesses for the three flaps. CONCLUSIONS: The present study demonstrated the frequent need for superficial fat layer manipulation when obtaining a thin perforator flap. To cope with various combinations of donor-site fattiness and different required thicknesses effectively, an appropriate thinning method should have increased adaptability, including the ability to control superficial fat layer thickness.

Superficial Fascia in the Cheek and the Superficial Musculoaponeurotic System.

The origins and validity of the term "superficial musculoaponeurotic system" (SMAS) is reviewed. Gray stated the superficial fascia connects the skin with the deep or aponeurotic fascia and consists of fibro-areolar tissue. Hollinshead wrote superficial fascia exists throughout the body and contains a variable amount of fat. In the head and neck, it encloses voluntary muscles in its deep portion. Skoog found superficial fascia was fixed to the dense, deep fascia by fibrous adhesions in the temporal, preauricular, and parotid area. Mitz stated "There is a 'superficial muscular and aponeurotic system' (SMAS) in the parotid and cheek areas." SMAS has an intimate relationship with the entire superficial fascia of the head and neck and divides the subcutaneous fat into 2 layers. Wassef found a continuous fibromuscular layer at the deep limit of the "subcutis," which corresponded to the "superficial fascia." Nakajima reported the subcutaneous adipofascial tissue was made up of 2 adipofascial layers. Macchi found 2 different fibroadipose connective layers bounded to the laminar connective tissue layer (SMAS). In the cheek, Hwang found horizontal fibrous connective tissues (membranous layer of superficial fascia) divided the superficial fascia into the superficial fatty layer and the deep fatty layer. Recently, Mitz explained the reason for the term SMAS. The "musculo+aponeurotic" component is based on histology of muscle cells, including the risorius, in the same structure to be surgically consistent. The aponeurotic cells belong to the same surgical layer. SMAS is not sufficient to replace the old term "superficial fascia" of the cheek area.

Does Botulinum Toxin Injection into Masseter Muscles Affect Subcutaneous Thickness?

BACKGROUND: Botulinum toxin (BoNT) is widely used to treat masseter muscle hypertrophy. Changes in the muscle thickness have been found in many studies, but there has been no report on changes in the thickness from the skin surface to the masseter muscle. OBJECTIVES: We aimed to use ultrasonography to measure not only changes in the muscle thickness but also changes in subcutaneous thickness. METHODS: This study enrolled 20 volunteer patients: 10 were assigned to an experimental group (injected with each side 25 U of botulinum toxin into both masseter muscles) and 10 to a control group (injected with normal saline). The thicknesses were measured before the injection and at 4, 8, and 12 weeks after the injection both at rest and during maximum muscle contraction. RESULTS: The subcutaneous thickness did not differ significantly over time either at rest (P = 0.063) or during maximal contraction (P = 0.392), or between the experimental and control groups at rest (P = 0.392) or during maximum contraction (P = 0.259). The muscle thickness in the experimental group differed significantly over time. CONCLUSIONS: Botulinum toxin injection only changes the muscle thickness and does not affect the subcutaneous thickness from the skin surface to the masseter muscle.

Bilayered Structure of the Superficial Facial Fascia.

Background: The superficial facial fascia comprises the superficial musculoaponeurotic system (SMAS) and the temporoparietal fascia (TPF) and is regarded as a continuous monolayer. However, some evidence indicates that the superficial facial fascia consists of 2 layers in specific areas. Objectives: The authors evaluated the superficial facial fascia for bilayered regions. Methods: Twenty fresh cadavers (40 hemifaces) were dissected to observe the superficial facial fascia. Twelve cadavers were dissected to assess tensile strengths of the superficial and deep layers of the SMAS. Specimens were obtained from 2 cadavers for histologic analysis. Results: The SMAS and TPF were separable into superficial and deep layers, with intervening areolar tissue. The deep TPF was continuous with the deep SMAS inferiorly and the subgalea anteriorly. The superficial orbicularis oculi was invested by the superficial SMAS, whereas the deep orbicularis and the platysma were invested by the deep SMAS. Thus, 2 key structures addressed in facial rejuvenation are positioned in different surgical planes. Conclusions: Study results support the belief that the superficial facial fascia comprises 2 layers, with the superficial orbicularis oculi and platysma invested by different layers. These findings have implications for facial rejuvenation techniques that involve management of the SMAS and TPF.

Nasal Anatomy and Function.

The nose is a complex structure important in facial aesthetics and in respiratory physiology. Nasal defects can pose a challenge to reconstructive surgeons who must re-create nasal symmetry while maintaining nasal function. A basic understanding of the underlying nasal anatomy is thus necessary for successful nasal reconstruction.

Managing the Difficult Soft Tissue Envelope in Facial and Rhinoplasty Surgery.

BACKGROUND: The nasal soft tissue envelope affects the final rhinoplasty result, and can limit the expected improvement. Currently, no dependable and objective test exists to measure the thickness of the nasal skin and underlying soft tissue. OBJECTIVES: This paper presents a simple, yet reliable method to determine the thickness of the soft tissue envelope. An algorithm is presented for treatment of the dermis and/or soft tissue apart from surgery of the underlying osseocartilaginous structures. METHODS: Seventy-five patients presenting for primary rhinoplasty underwent visual and ultrasound assessment of their nasal soft tissue envelope. At preoperative evaluation, the Obagi "skin pinch test" was used to assess the thickness of the nasolabial fold and whether or not the skin was oily. Patients were classified based on the pinch thickness. At time of surgery prior to injection of local anesthesia, ultrasonic assessment was done at the nasolabial fold, keystone junction, supratip, and tip to measure the thickness of the nasal dermis and underlying soft tissue. RESULTS: Patients determined to have thin, normal, and thick skin by the "skin pinch test" were found to have a nasolabial fold dermal thickness with an average of 0.7 mm (0.4-1.2 mm), 1.1 mm (0.8-1.8 mm), and 1.4 mm (0.7-2.0 mm). Patients determined to have thin, normal, and thick skin were found to have a dermal thickness at the keystone junction with an average of 0.3 mm (0.2-0.4 mm), 0.5 mm (0.3-1.1 mm), and 0.9 mm (0.6-1.2 mm), respectively. This difference in thickness also translated to the supratip and tip areas measured. However, all areas were also affected by the oiliness of the skin. Soft tissue thickness (SMAS and muscle) underlying the dermis was variable. Patients of non-Caucasian background were more likely to have a thicker soft tissue layer. CONCLUSIONS: The "skin pinch test" is an easy and reliable way for the surgeon to evaluate the thickness of the nasal soft tissue envelope. The rhinoplasty surgeon can make decisions pre- and postoperatively to treat patients with difficult soft tissue envelopes. LEVEL OF EVIDENCE 4.

Morphological and immunohistochemical analysis of the biocompatibility of resin-modified cements.

The aim of this double-blind randomized study was to evaluate the biocompatibility of resin-modified glass ionomer cements (RMGIC) by means of morphological and immunohistochemical analyses. RMGICs were selected and divided into four groups: Group CK (Crosslink Orthodontic Band Cement); Group RS (Resilience Light Cure Band Cement) Group RMO (RMO Band Cement), Group TP (Transbond Plus Light Cure Band), and Group C (Control-polyethylene). The materials were implanted in rat subcutaneous tissues, randomly selected for this study. After time intervals of 7, 15, and 30 days the tissues were submitted to morphological analysis. In immunohistochemical analysis, the immuno-marking of antibody CD68 was evaluated. The results obtained were statistically analyzed by the Kruskal-Wallis and Dunn tests (p < .05). In the morphological analysis after 7 days, Groups RS, RMO and TP showed more intense inflammatory infiltrate (p = .004) and only Group RMO presented greater intensity of multinucleated giant cells (p = .027). In the immunohistochemical analysis, Groups RMO and RS were observed to present a larger quantity of CD68+ (p = .004) in the time interval of 7 days and only Group RMO presented statistically significant difference for this parameter after 15 days (p = .026). In the time interval of 30 days, Group RMO presented the largest quantity of multinucleated giant cells (p < .004). The RMGICS Crosslink and Transbond Plus provided significantly better tissue biocompatibility than the Resilience and RMO Cements.