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Mandibular retraction

Introduction
Cause
Examine
Diagnosis

Introduction

Introduction Mandibular retraction is a malocclusion of the mandibular retraction caused by mandibular hypoplasia or congenital absence of the lower anterior teeth and pterygopalatine dysfunction. Clinical manifestations: 1. The mandibular retraction, the position of the upper jaw is basically normal, the anterior teeth are deeply covered, the upper anterior teeth are obviously inclined, the lower anterior teeth are bitten on the upper anterior teeth bulge or the sacral mucosa, and the lower lip is attached to the upper anterior teeth. Face, the occlusal relationship of the posterior teeth is far-integrated. 2. The mandible is retracted and the anterior teeth are deeply covered. The upper anterior teeth bite on the lower anterior teeth and the lower anterior teeth bite on the upper iliac mucosa, and the posterior occlusal relationship is far-integrated. 3. The mandibular retraction, the lower arch is smaller than the upper arch, the lower third of the face becomes shorter, and the lateral view of the lower jaw is more retracted. 4. For the upper anterior teeth, the upper anterior teeth are exposed to the outside of the mouth, and the side looks like the lower jaw and the ankle are retracted, and the upper and lower jaws are disproportionate.

Cause

Cause

Mandibular retraction is the lower jaw located behind the normal maxilla, usually including small jaw deformities caused by developmental disorders.

The cause of mandibular retraction:

(1) congenital developmental disorders: such as patients with first or second arch syndrome, bilateral or unilateral mandibular, mandibular ascending branch and body are also involved, and sometimes hearing bone also developed;

(2) inflammation: such as rheumatoid arthritis, adjacent otitis media will affect the development of the condyle and jaw;

(3) genetic factors: some mandibular retraction deformities have a clear family history;

(4) Trauma: Mandibular and condylar trauma can cause mandibular developmental disorders.

Examine

an examination

Related inspection

Maxillofacial examination temporomandibular joint examination mandibular movement examination skull radiograph

1. The oral model of the mandibular retraction is similar to that of the maxillary protrusion. The deep anterior teeth are often covered with deep lamination. The difference is that the maxillary position is normal and the mandibular condyle is retracted.

2. X-ray cephalometric measurements show that the SNB angle and face angle are smaller than the normal range. The ANB angle is greater than normal and the SNA angle is normal.

Auxiliary examination: This disease should pay special attention to the examination of X-ray cephalometric film.

Treatment measures:

1. Functional mandibular retraction therapy:

(1) Wear the maxillary active appliance with the plane guide plate, and at the same time remove the interdental interference as much as possible, and do the extra-pterygic function exercise. The middle occlusion habit has been basically completed, then the plane guide plate is changed into the inclined guide plate, etc. After the tooth resumes contact, it is necessary to continue to wear the inclined guide for a period of time;

(2) It is also possible to wear a non-functional planar occlusal upper and lower movable appliance and to make a type II traction between the jaws to improve the relationship between the upper and lower jaws.

2. For the stenosis of the maxillary arch and the mandibular retraction, use the plane guide and the movable appliance of the expansion spring to adjust the force to enlarge the upper arch. After the occlusion balance, the inclined guide can be used to guide the lower jaw forward to the normal position. Or use a fixed appliance.

3. The mandibular retraction, the posterior teeth of the neutral joint, the mandibular anterior teeth to the side of the lip, open the gap between the teeth.

4. Severe mandibular retraction, can be corrected by surgical orthodontics, and for ankle arthroplasty.

5. Mandibular retraction combined with maxillary protrusion, the deep coverage of such jaw deformity is the most serious, must be based on surgical orthodontic surgery, and then with orthodontic treatment.

6. Those who need surgery, can be prescribed before and after surgery, routine anti-infective medication.

Cure criteria:

1. Cure: Coverage coverage is normal, SNA angle, SNB angle, face angle, jaw angle, and SN angle are normal, the dentition is neat, the chewing function is good, and the side shape is coordinated.

2. Improvement: the coverage of the cover is normal, the angle of the SNB and the face angle are close to normal, the SNA angle, the jaw angle, and the SN angle are normal, the dentition is neat, the chewing function is good, and the side shape is relatively coordinated.

3. Unhealed: no improvement in symptoms and signs, chewing function and lateral shape.

Diagnosis

Differential diagnosis

Mandibular angle valgus: refers to the wide mandibular angle, the face looks like a ladder-shaped contour, lacking a soft feeling. One is too much subcutaneous fat, and the other is an excessively large buccal fat pad in the muscle space deep in the face.

Mandibular protrusion: abnormal relationship between the upper and lower arch can be expressed as mandibular protrusion, mesial and anterior teeth. The anterior teeth are reversed and partially combined with the posterior teeth. The facial surface can be expressed as a mandibular protrusion and a concave lateral shape with insufficient maxillary development.

Submandibular gland enlargement: The submandibular gland is the salivary gland of the jaw, one on each side. The lesion of the submandibular gland causes swelling of the submandibular gland.

1. fever, pulse, and breathing increase;

2. The edema of the submandibular and sinus areas is obvious, and the sublingual folds are red and swollen;

3. The submandibular gland is painful, tender, and the mouth of the catheter is red and has purulent discharge.

4. Chronic, often have submandibular discomfort or pain; alkaline secretions are discharged from the catheter;

5. When the catheter is blocked, the submandibular gland is swollen and painful, especially after entering the acidic diet, but gradually relieves after eating;

6. The submandibular gland is swollen, the quality is slightly hard and tender, and when the submandibular gland is squeezed, the catheter mouth has alkali or purulent discharge.