The abnormal relationship between the upper and lower dental arches can be manifested as mandibular protrusion, mesial malocclusion and anterior crossbite. It is mostly caused by poor breastfeeding posture, retention or premature loss of anterior teeth of deciduous teeth, congenital absence of upper permanent incisors, bad living habits, insufficient abrasion of canine teeth of deciduous teeth, systemic diseases and hereditary mandibular protrusion.
Reason:
1. Bad oral habits
(1) Bad breast-feeding posture, such as improper bottle feeding, requires the lower jaw to suck forward, which may cause the front teeth to bite back.
(2) There is a bad habit of biting the upper lip or mandibular protrusion, which leads to anterior teeth inversion and mandibular protrusion.
2. Local obstacles in dentition replacement
(1) Retention or premature loss of deciduous teeth may lead to malocclusion of individual anterior teeth or malocclusion of multiple anterior teeth.
(2) Maxillary deciduous molars fall off prematurely, and maxillary permanent anterior teeth move backward, which can form anterior crossbite.
(3) Underwear of deciduous teeth is higher than the plane of dental arch. In order to avoid the possible premature contact between the upper and lower deciduous teeth, the mandible will move forward or sideways, forming mandibular protrusion, resulting in anterior crossbite or anterior crossbite.
(4) Congenital absence of upper permanent incisors, such as common maxillary lateral incisors, can lead to hypoplasia of the anterior maxilla and form anterior crossbite.
3. Disease
(1) Chronic inflammation of palatal tonsil or lingual tonsil stimulates mandibular protrusion, which may lead to anterior crossbite with mandibular protrusion over time.
(2) Patients with cleft lip and palate often suffer from maxillary hypoplasia, which easily leads to anterior crossbite, mesial malocclusion and mandibular protrusion.
(3) Patients with rickets, whose calcium and phosphorus metabolism are disordered and their facial and maxillofacial muscles are abnormal, often lead to more serious mandibular protrusion or anterior teeth bite deformity.
(4) Endocrine diseases, such as hyperfunction of anterior pituitary, can cause mandibular protrusion deformity.
4. heredity
There is an obvious family history, and the mandibular and facial deformities are remarkable.
Extended data:
How to prevent:
1. During breastfeeding, correct bad breastfeeding posture and avoid excessive stretching of the baby's jaw.
2. It is particularly important to keep the gap between early deciduous teeth and early deciduous molars as much as possible. Pull out the reserved teeth as soon as possible, especially the reserved lower deciduous molars.
3. Due to chronic tonsillitis, tonsil diseases should be treated in time.
4. The malocclusion of anterior teeth caused by insufficient abrasion of deciduous teeth can make the mandible reset itself through excessive occlusion interference.
5. If it is caused by bad oral habits, the bad habits should be corrected as soon as possible.
References:
Baidu Encyclopedia _ Anterior Crossbite