Median muscles of the neck. Digastric muscle in occlusion
The geniohyoid muscle is located on the elevations of the incisors of the lower jaw and moves down, connecting with muscle fibers the muscle of the same name from the opposite side, weaving into the skin of the chin.
The Latin name for this muscle is musculus mentalis. Functionally, it performs the tasks of lifting the skin of the chin and forming a nearby mental fossa. If this muscle does not work properly (for example, chewing on one side or grimacing), spasms or hypertonicity of the muscle may occur. The result of improper muscle work will be a distortion of the appearance of the face and aggravation of mimic wrinkles with age.
Features of facial changes in the event of hypertonicity of the muscle is to change the correct operation of all muscles that control the lowering of the lower lip. Over time, this wrong facial expression takes root, and deep wrinkles form, which do not go away even after the cause is eliminated. The complex structure and functionality of the structures of the lower third of the face, such changes are difficult to correct.
Treatment
The methodology for eliminating hypertonicity provides for the possibility of using several methods of treatment. There are whole complexes of various exercises used for facial gymnastics. The high efficiency of such exercises is manifested only at the stage of prevention of the onset of the disease; already with the disease formed, such exercises will not be enough.
As a therapeutic measure, the most effective are injections of bolulotoxin. Even the most severe spasms can be eliminated with a few injections of the drug. In addition, it is worth remembering that high muscle activity can lead to a faster removal of the drug from the muscle structure.
Prevention
Due to the fact that muscle hypertonicity can cause significant changes appearance, the structure of the geniohyoid muscle should only work correctly. The situation is complicated by the fact that the chin muscle is in close connection with the rest of the muscles, thus significantly affecting the state of the jaw muscles. The complex structure of the location and connection with the rest of the muscles creates some difficulties if correction is necessary.
Thus, it is a much easier task to prevent and prevent mental muscle defects. by the most effective way, is the regular conduct of muscle gymnastics, which allows you to eliminate hypertonicity or spasms in the early stages.
Health
Why is it so important to monitor the condition of the geniohyoid muscle? The thing is that the need to correct the lower third of the face is a very complex and relevant topic in aesthetic medicine. The chin has its own structural features, since the muscles in this zone perform their own special tasks and carry significant loads.
In addition to the main tasks of chewing and speech, they are engaged in providing facial expressions. That is why, the human geniohyoid muscles must be subjected to condition monitoring and prevention, and their treatment requires much more intervention and complexity. Most often, the muscle suffers from hypertonicity or spasm.
A correctable mentalis muscle requires significantly more attention than any other area of the skin. Carrying out treatment with botulinum toxin injections requires a significant amount of calculations and great precautions.
Conclusion
It is worth saying that the human chin muscle is a very important component of the normal process of chewing, speech and facial expressions, and therefore requires a huge amount of attention to its condition. Even minor defects or muscle spasms can lead to the development of significant problems in speech or the process of chewing food. And therefore, you should regularly carry out preventive exercises that help relieve spasm and restore the normal functioning of the muscles of the chin.
Geniohyoid muscle(m. geniohyoideus) lies above m. mylohyoideus, starting from the mental spine of the lower jaw. Attachment - hyoid bone. Function: pulls the hyoid bone forward and upward; with a fixed hyoid bone, it lowers the lower jaw.
Mimic muscles
Mimic muscles are located mainly near the natural openings of the face and are woven into the muscles surrounding the cavities (nasal, ocular, oral cavity) with their fibers. Particularly large development facial muscles reach the circumference of the opening of the mouth. These muscles are also auxiliary in chewing function; in addition, they determine the configuration of the lips, nostrils, nasolabial folds, interlabial sulcus, skin folds, etc. On the skeleton, they are attached to the outer surface of the lower jaw (m. triangularis oris), to the zygomatic bone (m. zygomaticus), to the alveolar edge ( m. mentalis, m. incisivi). Among these muscles is m. orbicularis oris around the opening of the mouth. Their fibers go to the upper and lower lip and narrow or expand the oral fissure.
Articulation and occlusion. Types of occlusions. Characteristics of central occlusion.
Occlusion - (from lat. Occlusus - closed) - closing of the dentition or individual groups teeth - antagonists. Articulation - (from lat. Articulatio - connection) - all possible positions and movements of the lower jaw in relation to the upper, which is carried out with the help of masticatory muscles. Articulation is also a chain of alternating occlusions.
five main types of occlusion:
Central;
front;
Lateral (right or left);
Central occlusion is the closure of the dentition in which there is a maximum number of interdental contacts. At the same time, the head of the lower jaw is located at the base of the slope of the articular tubercle, and the muscles that adjoin the lower dentition with the upper (temporal, chewing, medial pterygoid) are simultaneously and evenly reduced. From this position, lateral shifts of the lower jaw are still possible.
Signs of central occlusion
Muscular signs: muscles that lift the lower jaw (chewing, temporal, medial pterygoid) simultaneously and evenly contract;
Articular signs: articular heads are located at the base of the slope of the articular tubercle, in the depths of the articular fossa;
Dental signs:
1) between the teeth of the upper and lower jaws there is the most dense fissure-tubercular contact;
2) each upper and lower tooth is connected with two antagonists: the upper one with the lower one of the same name and behind it; the lower one - with the upper one of the same name and in front of it. The exceptions are the upper third molars and the central lower incisors;
3) the middle lines between the upper and central lower incisors lie in the same sagittal plane;
4) the upper teeth overlap the lower teeth in the anterior region no more than ⅓ of the crown length;
5) the cutting edge of the lower incisors is in contact with the palatine tubercles of the upper incisors;
6) the upper first molar merges with the two lower molars and covers ⅔ of the first molar and ⅓ of the second. The medial buccal tubercle of the upper first molar falls into the transverse intertubercular fissure of the lower first molar;
7) in the transverse direction, the buccal tubercles of the lower teeth are overlapped by the buccal tubercles of the upper teeth, and the palatine tubercles of the upper teeth are located in the longitudinal fissure between the buccal and lingual tubercles of the lower teeth.
9. Central occlusion. Characteristic. The concept of the functional state of the central occlusion according to Ponomareva V.A., the central ratio of the jaws. Methods for determining the height of the lower face in the state of central occlusion and the central ratio of the jaws.
See No. 8 (central okl)
Central occlusion- this is the maximum intertubercular closure of the teeth. That is, when as many teeth as possible for this person are in contact with each other. (Personally, I have 24).
If the patient has no teeth, then there is no central (and no) occlusion. But there is central ratio.
Ratio is the position of one object in relation to another. When we talk about jaw ratio, we mean how the lower jaw relates to the skull.
Central ratio- the most posterior position of the lower jaw, when the head of the joint is correctly located in the articular fossa. (Extreme anterior-superior and mid-sagittal position). There may be no occlusion in the central relationship.
In the central ratio, the joint occupies the maximum upper-posterior position
Unlike all types of occlusion, the central ratio does not change throughout life. If there were no diseases and injuries of the joint. Therefore, if it is impossible to determine the central occlusion (the patient has no teeth), the doctor recreates it, focusing on the central ratio of the jaws.
It originates from the styloid process of the temporal bone.
Not far from the point of attachment, the muscle is perforated by the intermediate tendon of the digastric muscle.
Function:
Raises the hyoid bone and pulls it back.
3. Maxillofacial muscle (m. Mylohyoideus).
It starts on the inner surface of the lower jaw from the maxillo-hyoid line.
The posterior fibers are attached to the body of the hyoid bone, the anterior and middle fibers are connected to the same fibers of the opposite side, forming a tendon suture along the midline, which stretches from the middle of the chin to the hyoid bone.
Both maxillohyoid muscles are involved in the formation of the floor of the mouth and are called the diaphragm of the mouth (diaphragma oris).
Functions:
4. Geniohyoid muscle (m. Geniohyoideus).
It starts from the mental spine of the lower jaw.
Attached to the body of the hyoid bone.
Functions:
When the jaws are closed, the muscle raises the hyoid bone along with the larynx;
With a strengthened hyoid bone, it lowers the lower jaw (chewing, swallowing, speech).
Hyoid muscles:
1. Scapular-hyoid muscle (m. omohyoideus) - has two bellies: upper and lower, which are connected approximately at the middle of the length of the muscle by a tendon bridge.
The upper abdomen (venter superior) starts from the lower edge of the body of the hyoid bone outward from the attachment of the sternohyoid muscle, in the middle of the length of the muscle lies behind the sternocleidomastoid muscle, where it passes into the tendon bridge, which fuses with the sheath of the neurovascular bundle of the neck.
The lower abdomen (venter inferior) starts from the tendon bridge, is attached to the upper edge of the scapula.
Functions:
Pulls the vagina of the neurovascular bundle of the neck and prevents compression of blood vessels and nerves;
With a strengthened scapula, it pulls the hyoid bone backwards and downwards;
2. Sternohyoid muscle (m. Sternohyoideus)
It starts from the back surface of the handle of the sternum, the sternal end of the clavicle.
Attached to the lower edge of the body of the hyoid bone.
Between the medial edges of both muscles there is a space in which the plates of fascia grow together and form white line neck.
Function: pulls the hyoid bone down.
3. Sternothyroid muscle (m. sternothyroideus).
It starts on the back surface of the handle of the sternum and cartilage of the 1st rib.
Attaches to the oblique line of the thyroid cartilage of the larynx, lies in front of the trachea and thyroid gland.
Function: pulls the larynx down.
4. Thyrohyoid muscle (m. thyrohyoideus) is, as it were, a continuation of the sternothyroid muscle.
It starts from the oblique line of the thyroid cartilage.
Attached to the body and the greater horn of the hyoid bone.
Function: brings the hyoid bone closer to the larynx.
Deep neck muscles:
Lateral group:
1. Anterior scalene muscle (m. scalenus anterior).
It starts from the anterior tubercles of the transverse processes of C3-C6.
It is attached to the tubercle of the anterior scalene muscle on the 1st rib.
2. Middle scalene muscle (m. scalenusmedius).
From the transverse processes of C2-C7 to the 1st rib behind the groove of the subclavian artery.
3. rearstaircasemuscle(m. scalenus posterior).
From the posterior tubercles C4-C6 to the upper edge and outer surface 2 ribs.
Functions of the scalene muscles:
With a strengthened cervical spine, 1 and 2 ribs are raised, the chest cavity is expanded;
With a strengthened chest, the cervical spine is bent forward;
With unilateral contraction, the spine bends to the side.
Medial muscle group:
1. Long muscle of the head (m. longus capitis).
From the anterior tubercles of the transverse processes of C3-C6 to the inferior surface of the basilar part of the occipital bone.
Function: tilts the head and cervical part of the spine forward.
2. Long muscle of the neck (m. longus colli) - lies on the anterior surface of the bodies of all cervical vertebrae and the three upper thoracic vertebrae. Has three parts:
Vertical part: from the front surface of the C5-Th3 bodies to the C2-C4 bodies.
Lower oblique: from the anterior surface of the bodies of the first three thoracic vertebrae to the anterior tubercles C4-C5 of the cervical vertebrae.
Upper oblique: from the anterior tubercles of the transverse processes C3-C5 to the anterior tubercle of the 1st cervical vertebra.
Functions:
Flexes the cervical part of the spine;
With unilateral contraction, tilts the neck to the side.
10) CHECKING MUSCLE (M. MASSETER) STARTS FROM:
1. infratemporal surface and infratemporal crest of the main bone;
2. walls of the pterygoid fossa of the sphenoid bone;
3. digastric fossa of the lower jaw;
4. zygomatic arch;
Temporal surface of the greater wing of the sphenoid bone.
Option 3
1) THE BASIC MUSCLE MUSCLES ARE:
1. anterior belly of the digastric muscle;
2. maxillofacial muscle;
3. anterior pterygoid muscle;
4. temporal muscle;
Geniohyoid muscle.
2) THE PLACE OF TRANSITION OF THE FIXED MUCOSA INTO MOBILE IS CALLED:
1. covering mucous membrane;
2. moving zone;
3. fixed area;
4. transitional mucosa;
Neutral zone.
3) THE PATH THAT THE ARTICULAR HEAD PASSES WHEN THE LOWER JAW MOVES FORWARD AND DOWN, IS NAMED:
1. sagittal articular path;
2. transversal articular path;
3. direct articular path;
4. horizontal articular path;
There is no correct answer.
4) AT THE TRANSITION OF THE MUCOUS MEMBRANE FROM THE ALVEOLAR PROCESS TO THE LIP AND BEEKS, THERE IS FORMED:
1. transitional fold;
2. neutral zone;
3. pterygomandibular fold;
4. incisive papilla;
tubercle.
5) MOVEMENTS OF THE LOWER JAW CARRIED OUT AS A RESULT OF PREFERENTIAL BILATERAL REDUCTION OF THE LATERAL PLATEROID MUSCLES, PARTIALLY TEMPORAL AND MEDIAL PLATEROID:
1. vertical;
2. horizontal;
3. sagittal;
4. transversal;
Side.
6) MIMIC MUSCLES PARTICIPATE IN:
1. grasping food, holding it in the vestibule of the oral cavity;
2. balance functions;
3. warming the air;
4. digestion of food;
There is no correct answer.
7) THE LOWER JAW FUNCTIONS:
1. balance;
2. articulation and swallowing;
3. breathing and planning of conscious muscle movements;
4. sense of smell;
There is no correct answer.
8) THE ARTicular fossa is divided:
1. on the anterior intracapsular part;
2. on the anterior extrapyramidal part;
3. on the medial intracapsular part;
4. on the posterior extrapyramidal part;
There is no correct answer.
9) THE ANGLE FORMED BETWEEN THE LINES OF THE SAGITTAL AND TRANSVERSAL POSITION OF THE ARTICULAR HEAD IS CALLED:
1. Gizi angle;
2. gothic corner;
3. Bennett angle;
4. sagittal incisal angle;
transversal angle.
10) DISPLACEMENT OF THE LOWER JAW TO THE SIDE (SIDE MOVEMENT) IS CARRIED OUT:
1. in phase 1 of lower jaw movements;
2. in the 2nd phase of lower jaw movements;
3. in the 3rd phase of lower jaw movements;
4. in the 4th phase of lower jaw movements;
In the 5th phase of the movements of the lower jaw.
Situational tasks :
When making chewing movements, muscles are involved in lowering the lower jaw down.
When chewing food, the lower jaw makes a cycle of movements. Gysi presented these movements in the form of a diagram. The initial moment of movement is the position of the central occlusion. Describe the following pattern of jaw movements.
The vertical movements of the lower jaw correspond to the opening and closing of the oral cavity. The lowering of the lower jaw is carried out due to the gravity of the jaw itself and with active bilateral contraction of the muscles going from the lower jaw to the hyoid. When lowering, the lower jaw drops slightly, then significantly and maximally. This corresponds to the movement of the articular heads. What movements do the articular heads make when lowering the jaw.
Name the muscles involved in the movement of the lower jaw
Name the muscles involved in the formation of emotions on the face.
When working with scientific literature the student is given the opportunity to choose the best way to obtain the necessary information, which allows the best way carry out the learning process. The implementation of SRW consolidates the theoretical knowledge gained in lectures and practical exercises.
NIRS consists of the following sections:
a) introduction - justification for the choice of topic, general characteristics research objectives, statistical data;
b) the main content of the work
c) a list of used literature, including at least 5-6 sources (2-3 of them no later than the last 3 years of publication), links to the Internet.
Themes:
The structure of the temporomandibular joint.
The structure of the ligamentous apparatus of the temporomandibular joint.
Basic and additional literature:
| No. p / p | Name, type of publication | Author(s), compiler(s), editor(s) | Place of publication, publisher, year | In library | At the department |
| Orthopedic dentistry. Applied Materials Science: textbook | V. N. Trezubov, L. M. Mishnev, E. N. Zhulev [and others] | M. : Medpress-inform, 2011. | |||
| Propaedeutic dentistry: textbook. for honey. universities | ed. E. A. Bazikyan, O. O. Yanushevich | M. : GEOTAR-Media, 2012. | |||
| Dental technique: textbook | ed. M. M. Rasulov, T. I. Ibragimov, I. Yu. Lebedenko | M. : GEOTAR-Media, 2010. | |||
| Dental materials science: study guide | V. A. Popkov, O. V. Nesterova, V. Yu. Reshetnyak [and others] | M. : Medpress-inform, 2009. | |||
| Therapeutic dentistry: hands. to pract. occupations: textbook. allowance | Yu. M. Maksimovsky, A. V. Mitronin | M. : GEOTAR-Media, 2011. | |||
| Phantom course of therapeutic dentistry: textbook | A. I. Nikolaev, L. M. Tsepov | M. : Medpress-inform, 2009. |
LESSON #6
Lesson topic: BIOMECHANICS OF THE CHEWING MACHINE. MOVEMENTS OF THE LOWER JAW, RELATIONSHIP OF ALL LINKS OF THE DENTAL SYSTEM. PHASES OF CHEWING MOVEMENTS OF THE LOWER JAW DURING BITTING AND MEETING FOOD. ANGLE OF THE SAGITAL ARTICULAR AND INCITIVE PATH. RATIO OF THE DENTAL ARRIVALS WHEN THE LOWER JAW IS EXTENDED.
Form of organization educational process : practical lesson.
The value of studying the topic: The manufacture of any orthopedic medical device is a complex and capacious process, which, of course, requires a high qualification of a specialist doctor and a clear and correct execution one or another treatment phase. The theoretical knowledge of the doctor is also important. Understanding of all mechanisms of functioning of the chewing apparatus. One of the most important and complex mechanisms is the study of the biomechanics of the masticatory apparatus.
Learning objectives:
1. Common goal:
Formation of students' general cultural and professional competencies:
ability and readiness for logical and reasoned analysis, for public speech, discussion and polemics, for editing texts of professional content, for educational and pedagogical activities, for cooperation and conflict resolution, for tolerance (OK-5);
the ability and willingness to carry out their activities, taking into account the moral and legal norms accepted in society, to comply with the rules of medical ethics, laws and regulatory legal aspects for working with confidential information, to maintain medical secrecy (OK-8);
the ability and readiness to form a systematic approach to the analysis of medical information, based on the comprehensive principles of evidence-based medicine based on finding solutions using theoretical knowledge and practical skills in order to improve professional activities (PC-3);
the ability and willingness to analyze the results of their own activities to prevent medical errors, while being aware of disciplinary, administrative, civil, criminal liability (PC-4);
The ability and readiness to work with medical and technical equipment used in working with patients, to own computer equipment, to receive information from various sources, to work with information in global computer networks; apply the possibilities of new modern information technologies to solve professional tasks(PC-9).
2. Learning goal:
- know the basics of the biomechanics of the chewing apparatus;
- be able to characterize all kinds of movements of the lower jaw relative to the upper;
- own the algorithm for performing chewing movements.
Topic study plan:
Muscles above the hyoid bone(Fig. 180)
The digastric muscle (m. digastricus) has an intermediate tendon and two bellies in the middle part. The posterior belly of the digastric muscle starts from the incisura mastoidea of the temporal bone and goes forward and downward, reaching the hyoid bone. Its anterior abdomen starts from the eponymous fossa of the lower jaw and is directed back and down. At the hyoid bone, both bellies are connected by a tendon, which is attached to the greater horn of the hyoid bone by means of a loop.
Innervation: the anterior belly of the muscle comes from the first gill arch and is innervated by the V cranial nerve, the posterior belly is from the second gill arch and is innervated by the VII cranial nerve.
180. Muscles of the neck (above and below the hyoid bone) lateral.
1-gl. sublingualis; 2 - m. geniohyoideus; 3 - glandula submandibularis; 4 - glandula parotis; 5 - m. mylohyoideus; 6 - m. omohyoideus; 7 - m. sternohyoideus; 8 - m. sternothyroideus; 9 - m. scalenus anterior; 10 - m. scalenus medius; 11 - m. scalenus posterior; 12 - m. digastricus.
Function. With simultaneous contraction of the digastric muscles and muscles below the hyoid bone, the lower jaw descends. If the muscles below the hyoid bone are relaxed, and chewing muscles are reduced, the hyoid bone is pulled up. Such movements are made during the act of chewing and swallowing.
The stylohyoid muscle (m. stylohyoideus) is fusiform, located above the posterior belly of the digastric muscle. It starts from the styloid process of the temporal bone, goes down and in the direction of the hyoid bone, where it is attached at the place of fusion of the body with the large horn. At the hyoid bone, the posterior belly of the digastric muscle passes through the tendon of the stylohyoid muscle.
Innervation: develops from the II branchial arch and is innervated by the VII cranial nerve.
Function. Displaces the hyoid bone up and back. This movement is made during the act of swallowing.
The geniohyoid muscle (m. geniohyoideus) is more superficial than the previous muscle. It starts from the spina mentalis and is attached to the body of the hyoid bone. The muscle is shaped elongated triangle, apex facing forward.
Innervation: originated from the intermaxillary muscle and is innervated by the XII pair of cranial nerves.
Function. With a fixed hyoid bone, it lowers the lower jaw.
The jaw-hyoid muscle (m. mylohyoideus) has the form of a plate that fills the entire space between the hyoid bone and lower jaw(). It is also called the diaphragm of the oral cavity, as it forms the bottom of the oral cavity and separates it from the neck. Above the maxillohyoid muscle are the tongue and the sublingual salivary gland. The muscle starts from the linea mylohyoidea of the lower jaw, its bundles are oriented towards the midline and back. In the midline, the right and left muscles form a fibrous suture (raphe). Only the posterior muscle bundles are attached to the body of the hyoid bone.
Innervation: is a derivative of the I gill arch and is innervated by the V pair of cranial nerves.
Function. Accepts and displaces the hyoid bone forward. With simultaneous contraction of the muscles below the hyoid bone and m. mylohyoideus lower jaw.
Layers of loose connective tissue above the hyoid bone
1. Lateral cellular layer, bounded from above by the mucous membrane of the oral cavity, from below - m. mylohyoideus, medially - m. genioglossus, laterally - by the lower jaw. In this fiber is the sublingual salivary gland.
2. In the fiber layer between the right and left hyoid-lingual muscles, the veins of the tongue pass.
3. In fiber between m. genioglossus and m. geniohyoideus is the hypoglossal nerve.
4. In fiber between m. platysma and m. digastricus is the submandibular salivary gland.
Muscles below the hyoid bone
The scapular-hyoid muscle (m. omohyoideus) (Fig. 180) is long and thin, has two bellies. The lower one starts from the upper edge of the scapula and its lig. transversum scapulae superius, then goes up and medially. Departing 4-5 cm from the beginning of the sternocleidomastoid muscle, the scapular-hyoid muscle passes behind it, interrupted here by the tendon bridge. From it begins the upper abdomen of the scapular-hyoid muscle, which is attached to the lower surface of the body of the hyoid bone.
Innervation: by origin it belongs to autochthonous muscles and is innervated by nn. cervicales (CI-III).
Function. Lowers the hyoid bone. With bilateral contraction, it strains the pretracheal fascia.
The sternohyoid muscle (m. sternohyoideus) is better developed than the previous one. It starts from the inner surface of the sternum handle, the partially sternal end of the clavicle and the capsule of the sternoclavicular joint, then rises, being on the side of the trachea, covering the thyroid gland and attaches to the lower edge of the body of the hyoid bone.
The innervation and origin are the same as the previous muscle.
The sternothyroid muscle (m. sternothyroideus) is located medially from the previous muscle. It starts from the inner surface of the handle of the sternum and I rib. Attached to the oblique line of the thyroid cartilage of the larynx.
Innervation: nn. cervicales (CI-III).
Function. Lowers the hyoid bone.
Thyrohyoid muscle (m. thyrohyoideus) is short and wide. It starts from the oblique line of the thyroid cartilage and is attached to the large horns of the hyoid bone.
Innervation: nn. cervicales (CI-II).
Function. It lowers the hyoid bone, and when the hyoid bone is fixed, it raises the larynx.
