Study of the functional relationships between the buccinator muscle and the connective tissue of the cheek in humans

BACKGROUND

The buccinator muscle derives from the mesenchyme of the second pharyngeal arch. In adults, it has a quadrilateral shape, occupying the deepest part of the cheek region. Its function is complex, being active during swallowing, chewing, and sucking. To our knowledge, there are no studies that have specifically analyzed the relationship of the buccinator muscle fibers and neighboring connective tissue of the cheek in humans, neither during development nor in adults. Such relationships are fundamental to understand its function. Thus, in this study the relations of the buccinator muscle with associated connective tissue were investigated.

METHODS

The buccinator muscle region was investigated bilaterally in 41 human specimens of 8-17 weeks of development. Moreover, four complete adult tissue blocks from human cadavers (including mucosa and skin) were obtained from the cheek region (between the anterior border of the masseter muscle and the nasolabial fold). All samples were processed with standard histological techniques. In addition, subsets of sections were stained with picrosirius red (PSR). Furthermore, immunoreactivity against type I and III collagen was also studied in adult tissues.

RESULTS

The buccinator muscle showed direct relationships with its connective tissue from 8 to 17 weeks of development. Collagen fibers were arranged in septa from the submucosa to the skin through the muscle. These septa were positive for type I collagen and presented elastic fibers. Fibrous septa that were positive for type III collagen were arranged from the lateral side of the muscle to the skin.

CONCLUSIONS

The intimate relationship between buccinator muscle fibers and cheek connective tissue may explain the complex functions of this muscle.

AV Malformation Within Buccinator Muscle-A Unique Finding

Arteriovenous malformations (AVMs) are most commonly reported in the brain whereas in head and neck region they are rare i.e. incidence is 0.1% of the general population. Commonly managed by surgical excision, embolization, sclerotherapy. Here we present a case of 18-year-old female with AV malformation within buccinator muscle which was recurrent and was treated with compartmentalization followed by sclerotherapy and surgical excision.

Finite element analysis of the stress released by buccinator muscle in the mandibular dental arch during sucking habits

Objectives

The effect of buccinator muscle on the mandible need to be more clarified. Finite element method used to estimate the effect of the buccinator during abnormal function on the size and shape of the mandible.

Methods

Three-dimensional model of human mandible using Finite element analysis referring to dry normal mandible with teeth as a template, The mechanical characteristic of the materials were supposed to be homogenous, isotropic, and linear elastic. Auto mesh order used to discredit the model under analysis to numerous elements; every element includes numbers of apexes called nodes; the association of elements and nodes called the finite element mesh. The force of (2 ​gm/cm²) had been applied perpendicular to buccal surface of posterior teeth within the mandible representing normal buccinators muscle function on the mandible. While for simulation of abnormal suckling, buccinators muscle force (21 ​gm∖cm²) applied to the same area.

Results

abnormal size and shape of the mandible with malocclusion especially at the posterior teeth area in transverse direction in addition to backward pressure on the chin and anterior teeth result from abnormal suckling force.

Conclusion

It could be concluded that abnormal function of buccinators during growth and development could result in size and shape variation of the mandible with concomitant malocclusion.

New method of recording the functional activity pattern of the buccinator from the mucosal surface

OBJECTIVES

The buccinator (BUC) is an important muscle for oral function. Since it lies deep in the facial skin, recording its activity is difficult; thus, studies on its function are limited. We developed a method to access the deep facial muscles from the mucosal side. The aim of this study was to test the reliability of the new recording method for the BUC and to investigate the BUC behavior in typical facial functions.

METHODS

To evaluate the new method, BUC activities were recorded simultaneously with a gel-type electrode on the skin and the newly developed surface electrode on the buccal mucosa. Electromyographic (EMG) activities in function, such as chewing and swallowing, along with the activities of the lower orbicularis oris (OO), zygomaticus major, masseter, and digastric muscles, were compared using the two recording methods. EMG activities among various tasks were compared using normalized values based on those obtained during maximum lip closure (MaxLC).

RESULTS

The new surface electrode was made of gold plates on a thin plastic fixed to a stainless-steel wire frame and weighed less than 1 g. The BUC activity recorded from the mucosa was the highest during a corner-pulling task and was low during clenching. The BUC was active during MaxLC, similar to the OO, and the BUC activity pattern among tasks recorded from the mucosa was identical to that reported by previous studies using intramuscular electrodes. The new electrode evaluated the BUC activities quantitatively, and the recordings by the new electrode were free from contamination.

CONCLUSIONS

The findings of this study confirmed the reliability of the new BUC recording method. It could be easily placed correctly within seconds, without the need for cleansing or sterilizing the skin. The BUC and OO were active during a MaxLC task, indicating that the BUC assists lip closure by pulling the corners of the mouth. The basic facial functions evaluated, including chewing, were similar to those studied by intramuscular electrodes.

A glimpse of past, the temporo-buccinator band of Hovelaque, or the buccotemporal fascia of Zenker

Only a few studies published until now have described the fascial-tendinous complex between the temporal and the buccinator muscles, which will be reviewed here. In 1957, the "temporo-buccinator band" (TBB) was described by Gaughran, who gave credit to Hovelaque for its first description in 1914. Zenker coined it in 1955 as the "buccotemporal fascia" (BTF). A buccal extension of the temporal muscle tendon extends from the temporal crest of the mandible to insert within the buccinator muscle, anterior to the pterygomandibular raphe, and posterior to the parotid duct that perforates the buccinator. That tendinous expansion is embedded within the buccotemporal fascia, which is oriented antero-infero-medially and joins the buccopharyngeal fascia, forming the TBB/BTF, above which we find the buccal fat pad. The buccal nerve and artery cross this anatomical structure. The TBB/BTF is an additional layer closing the pterygomandibular space anteriorly, and its knowledge is needed for practitioners performing inferior alveolar nerve blocks.

Diverticulum of the buccal mucosa: a rare case report and review of the literature

Background

Cases of diverticula of the buccal mucosa are extremely rare. Literature searches of databases such as PubMed/MEDLINE for this condition have revealed only 10 case reports. In this case report, we describe our experience in the management of this rare condition and review the previous 10 previously reported cases.

Case presentation

A 66-year-old man presented with a pouch containing inspissated food debris located posterior to the papilla of the parotid duct in his left buccal mucosa. The diagnosis of a diverticulum arising from the buccal mucosa was confirmed based on clinical and radiographic findings. Gross examination of the locally resected tissue specimen revealed a pouch measuring 14 mm in diameter and 8 mm in depth, that was whitish in color and had an elastic, soft, and smooth surface. Microscopic examination revealed a cyst-like lesion lined by stratified squamous epithelium and granulation tissue, with a chronic inflammatory infiltration in the peripheral stromal tissue of the epithelial layer. After surgical excision of the lesion, there was no recurrence during the follow-up period of 5 years and 10 months.

Conclusions

We have presented a rare case of a diverticulum of the buccal mucosa. This is the first report of a case confirmed not only by the clinicopathological findings, but also by computed tomography and magnetic resonance imaging findings. From the magnetic resonance imaging and intraoperative findings, we inferred that the diverticulum was caused by an idiopathic developmental anomaly due to a partial defect of the buccinator muscle.

Taenia Solium: A Rare Expression in Oral Cavity

Cysticercosis is a helminthic infection caused by the larval stage of pork tapeworm, Taenia solium. The worm requires different hosts during its different stages of development. Humans are the definitive hosts and harbor the adult worms, while pigs harbor the larval stage and act as the intermediate hosts. This disease is endemic in developing countries of the world where poor sanitary conditions are prevalent. It manifests mostly in form of lesions in the subcutaneous tissues, brain and skeletal muscles. It is interesting to note that the oral cavity is a rare site for its occurence and pose as a diagnostic challenge for the clinicians. Here, we report one such rare case of an isolated lesion of the oral cavity involving the buccinator muscle.

Morphometric aspects of the facial and skeletal muscles in fetuses

OBJECTIVES

There are few research reports providing a comparison of the muscle fiber morphometry between human fetuses and adults. Data on fetal and adult muscle fibers would be valuable in understanding muscle development and a variety of muscle diseases. This study investigated human muscle fiber growth to clarify the difference between the facial muscles and other skeletal muscles.

METHODS

The materials were obtained from three male fetuses (6-month-old) and 11 Japanese male cadavers aged 43-86 years (average: 71.8). Human buccinator muscles (facial muscles), masseter and biceps brachii muscles (skeletal muscles) were resected. We counted the muscle fibers and measured their transverse area. We also calculated the number of muscle fibers per mm(2) (NMF) and the average transverse area of the muscle fibers (TAMFs).

RESULTS

The average of the NMF of the buccinator, masseter and biceps brachii muscles in fetuses had, respectively, 19, 37, and 22 times as many fibers as those in adults. The average fetus/adult ratios of the TAMF of the buccinator, masseter and biceps brachii muscles were 4.0%, 2.4%, 4.1%, respectively.

CONCLUSIONS

The average NMF for all kinds of muscles decreased after birth; however, the peak in life-span or decreases with the aging process tended to vary with the kind of muscles examined. The average TAMF for all kinds of muscles enlarged after birth. We considered that the enlargement of the TAMF was connected with the emergence of fetal movements and functional demands after birth.

Blending of the lateral deep slip of the platysma muscle into the buccinator muscle

PURPOSE

The aim of this study was to clarify the prevalence of blending of the lateral deep slip of the platysma into the buccinator, and the morphologic and spatial relationships thereof.

METHODS

The lateral deep slip of the platysma was investigated in 42 specimens of embalmed adult Korean cadavers.

RESULTS

The lateral deep slip of the platysma was observed in 17 of the 42 specimens (40.5 %). When present, it divided from the deep portion (16 specimens, 38.1 %) or the lateral portion (1 specimen, 2.4 %) of the platysma pars modiolaris. The lateral deep slip passed deep to the facial artery, where it blended into the inferior part of the buccinator. The blending site was located inferolateral to the modiolus. After blending into the buccinator, the fibers of the lateral deep slip coursed longitudinally with the inferior fibers of the buccinator.

CONCLUSION

The present description of the topography of the lateral deep slip of the platysma and its relationship with surrounding structures could improve the understanding of the detailed movements of the lower face and the related EMG activities, with the data also being useful when performing facial surgery.