How Do I Treat Crowding Teeth?

Crowded teeth are the most common, with overcrowding seen in 60% to 70% of malformed patients.

Crowded teeth

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Crowded teeth are the most common, with overcrowding seen in 60% to 70% of malformed patients.

Chinese name

Crowded teeth

Department

Dental

Classification

Simple crowding and complex crowding

Disease ratio

60% to 70%

1. Tooth crowding is divided into simple crowding and complex crowding. Simple crowding is manifested as the teeth are disorderly arranged due to insufficient clearance, which affects the relationship between dental arch shape and occlusion. Simple crowding can be regarded as dental malocclusion, which is generally not accompanied by jaws and teeth. The relationship between the arches is irregular, and there are few abnormalities in the oral and maxillofacial system. The molar relationship is neutral and the facial shape is basically normal. In complex congestion, in addition to the congestion caused by the irregular tooth volume, there is also an irregular relationship between the jaw bone and the dental arch, which affects the patient's facial shape, and is sometimes accompanied by abnormalities in the function of the oral and maxillofacial system. It's just a symptom, not the main aspect of the error.

2. Index of tooth crowding Tooth crowding is divided into 3 degrees according to its severity.

Slightly crowded (I degree crowded): There is a crowd of 2 to 4 mm in the dental arch.

Moderate crowding (II degree crowding): The dental arch is crowded between 4 and 8mm.

Severe crowding (III degree crowding): The dental arch is crowded more than 8mm.

1. The following factors should be considered when determining orthodontic extraction:

(1) Teeth crowding: direct measurement of the jaw model to get tooth crowding. Every 1mm of congestion requires 1mm of arch clearance. The greater the degree of congestion, the greater the possibility of tooth extraction.

(2) Degree of dental arch protrusion: To move the incisor of the anterior process to the tongue side, the arch gap is required to restore the normal position. Each incision of the incisor incisor moves 1mm to the lingual side, requiring a 2mm arch gap. The more the incisor protrudes, the more likely it is that the tooth will be extracted.

(3) Spee curve height: The vertical distance between the buccal tip of the second premolar to the plane formed by the buccal groove of the second permanent molar on the mandibular dental arch model is the Spee curve height. For every 1mm Spee curve, a 1mm arch gap is required.

(4) Advancement of the molars: In determining the extraction, the extraction space occupied by the molar advancement should be taken into account. If tooth extraction is used, it is inevitable that the anterior molar moves when the gap is closed. Orthodontists can use different measures to control the amount of molar advancement: when using strong anchorage, the space occupied by molar advancement does not exceed 1/4 of the extraction gap; when using moderate anchorage, it is 1/4 1 / 2; at least 1/2 for weak support.

(5) Vertical bone surface type: There are three types of development in the vertical direction of the face. Usually, the three are distinguished by the steepness of the mandibular plane. The average SN-MP angle of normal vertical bone surface type was 34.3 ° (± 5 °), and the FH-MP angle was 27.2 ° (± 4.7 °). When the SN-MP angle is greater than 40 °, or the FH-MP angle is greater than 32 °, it is a vertical overdevelopment, which is called a "high-angle" case. The SN-MP angle is less than 29 ° or the FH-MP angle is less than 22 °, which reflects insufficient vertical development and is a "low-angle" case (Figure 2).

In terms of orthodontic extraction, high-angle and low-angle cases have different considerations: high-angle case extraction standards can be appropriately relaxed, and low-angle cases should be strictly controlled. This is because:

In the high-angle cases, the palate is usually retracted, and the incisors should be upright at the end of treatment to maintain a coordinated nasal-lip-sacral relationship. The more upright incisors can also compensate for the vertical imbalance of the bones and establish a suitable upper and lower incisors. Morphological and functional relationships. In the case of low-angle cases, the opposite is the case. In most patients, the sacrum prolapses, and the incisors should be compensated for lip tilting. This not only benefits the facial shape, but also the function of the incisors.

In high-angle cases, the chewing muscles are weak, jaw bone density is low, the molars are easy to move forward and rise, and the extraction space is easier to close. At the same time, the advancement of molars is beneficial for the correction of the anterior teeth tendency often associated with high-angle cases. . Contrary to low-angle cases, strong chewing force, high bone density, and anterior molars are not easy to move forward and rise. The closing of the extraction space is mainly accomplished by the distal and mid-anterior movement, and excessive adduction of the anterior teeth is not conducive to low-angle cases. Deep correction of the front teeth.

When aligning the dentition by pushing the molars backwards or expanding the dental arch, it can cause the mandibular plane angle to widen, which adversely affects the face shape and anterior tooth coverage of high-angle cases, but it does affect low-angle cases. More favorable.

There are also differences between high-angle and low-angle cases when deciding on the tooth position for extraction: high-angle cases are better for the control of anterior teeth if lower teeth are removed; if low-angle cases require tooth extraction, it is advisable to remove the teeth near the front of the arch. It is easy to close the extraction space and is conducive to opening the occlusion.

(6) Sagittal bone pattern (Figure 3): When the sagittal relationship of the maxillary and dental arches is coordinated and the ANB angle is normal, if extraction is required, usually the upper and lower arches are removed symmetrically (unless the Bolton index is not adjusted). However, if the sagittal relationship of the upper and lower arches is not adjusted, the difference between the upper and lower arches should be considered when deciding whether to extract the tooth. Type wrong maxillary dental arch is relatively forward, and lower jaw dental arch is relatively backward. The ANB angle is relatively large. To compensate for this skeletal irregularity, the lower incisor can be slightly lip tilted at the end of treatment. Mandibular extraction should be cautious. Type III errors are opposite. Because the upper jaw is relatively underdeveloped, the lower jaw is relatively large, and the ANB angle is small. At the end of the treatment, the upper incisor can be slightly tilted and the lower incisor slightly tilted to compensate for type III skeletal deformities. Especially cautious.

(7) Facial soft tissue profile: When determining extraction and non-extraction correction, the soft tissue profile,

In particular, the analysis and evaluation of the nasal-lip-palate relationship. More commonly used people have the following two measurement indicators.

Distance from upper and lower lips to aesthetic plane: The aesthetic plane is formed by connecting the tip of the nose with the anterior point of soft tissue (Figure 4).

Nasolabial angle: the angle formed by the nasal column point, the lower nose point and the upper lip bump (see Figure 4).

Table 1 shows the averages and standard deviations of the normal measurements in Beijing with good shape. There is no significant difference in gender between men and women.

(8) Growth and development: Tooth crowding, especially complex crowding, another factor that must be considered when determining whether or not to extract a tooth is growth and development. Growth and development assessment should determine the patient's current stage of development and choose the appropriate treatment. The treatment of simple crowding can be performed during the rapid growth period of adolescence; complicated crowding with irregular jaw relations, if you consider the control of jaw growth, orthopedic treatment should be performed 1 to 2 years before the rapid growth period. Growth assessment also includes predicting the craniofacial growth of the patient during orthodontic treatment. Due to the difference between normal and wrong and between individuals, there is a bias in using normal average growth data for the growth prediction of patients with wrong individuals.

2. Correction of tooth crowding during the period of tooth replacement The treatment of tooth crowding during the period of tooth replacement is the content of preventive and blocking correction of professional orthodontics. The focus of treatment is to monitor the replacement process of primary and permanent teeth to promote dentition and Normal development. mainly include:

(1) Prevention and treatment of deciduous tooth caries.

(2) Elimination of bad oral habits.

& nbs

The diet should be light, pay attention to hygiene, and match the diet reasonably.

There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.

The cause of tooth congestion is that the amount of teeth and bone are not adjusted, the amount of teeth (total width of the teeth) is relatively large, the amount of bone (total length of the alveolar arch) is relatively small, and the length of the dental arch is insufficient to accommodate all the teeth on the dental arch. Tooth and bone mass are affected by both genetic and environmental factors.

1. The chewing organs showed a tendency to weaken during human evolution. The weakening of the chewing organ is the fastest muscle, the second bone, and the slowest teeth. This unbalanced degradation constitutes the background of the ethnic evolution of human crowding.

2. The number, size and morphology of teeth are strongly controlled by heredity, and the size, position and morphology of jaws are also affected by heredity to some extent. Oversized teeth, multiple teeth, and some crowded teeth caused by underdeveloped jawbone are significantly related to genetic factors.

3. The replacement of primary and permanent teeth in environmental factors plays an important role in the occurrence of tooth crowding. Premature loss of deciduous teeth, especially the loss of the second molar, will result in a reduction in tooth length and congestion due to insufficient clearance during permanent tooth eruption. The retention of deciduous teeth occupies the position of the dental arch, and the subsequent permanent teeth must not eruption and appear crowded. Some bad oral habits can also cause teeth crowding. For example, long-term biting of the lower lip can cause the lower front teeth to tilt and merge.

Laboratory inspection:

Other auxiliary checks:

X-ray head shadow measurement, dental arch measurement analysis.