What is the cause of congenital tooth loss

The main symptoms of congenital missing teeth are missing teeth or incomplete tooth development. In mild cases, one or two teeth are missing, which has little impact. In severe cases, the number of missing teeth is six or more, which will affect a person's chewing function. At the same time, missing teeth will also make a person look old. Congenital tooth loss is also associated with microdontia.

Main causes

Familial genetic factors, systemic developmental defects

Disease classification

Congenitally missing teeth are generally classified according to degree:

Mild and moderate congenital missing teeth:

Usually two or more teeth are missing, but no more than six, excluding the third molars.

Severe congenital missing teeth:

Missing 6 or more teeth, excluding third molars. The disease is often accompanied by microdontia.

Oligodontia:

The loss of most teeth in the entire mouth is usually the oral manifestation of a systemic deficiency disease.

Causes

Congenital missing teeth may be caused by familial genetic factors, and most patients are members of a family with a history of the disease. The genetic characteristics are very complex and are still not fully understood. Congenital missing teeth can also occur in individuals without a family history of the disease.

Congenital missing teeth are also a common clinical feature of many systemic developmental defects such as hypohidrotic ectodermal dysplasia, Down syndrome and chondroectodermal dysplasia. Cleft lip and palate can cause developmental disorders of the alveolar bone in the involved area and may also lead to the loss of teeth in this area, especially the upper lateral incisors.

Patient population

In the normal population, the incidence of congenital missing teeth in the permanent dentition is 3.5% to 6.5%; females are more susceptible than males, with the male-female ratio being 2:3. The prevalence of severe congenital tooth loss in the permanent dentition in the population is 0.3%. The prevalence of primary dentition is 0.1% to 0.9%, with no significant difference between sexes.

Location of teeth most likely to be lost: The upper lateral incisors, maxillary and mandibular second premolars and lower incisors are most commonly affected. It is rare for upper central incisors, maxillary and mandibular canines, or first molars to be lost congenitally, but these teeth may be lost in the mouths of patients with severe congenital agenesis.

Disease characteristics

The variable clinical presentation complicates the planning and management of treatment for patients. The teeth are often conical or undersized, which presents aesthetic and functional problems. When a fixed restoration is placed, preparing the tooth can be difficult. Due to the lack of undercuts, there are problems with the retention of removable dentures. Delayed or abnormal eruption of permanent teeth. If the upper lateral incisors are too small or missing, the upper canines may shift. The retained deciduous teeth may lie low, and the adjacent permanent teeth may tilt toward the space, causing the space to narrow. Often these retained deciduous teeth develop bone adhesions, which must be considered during surgical and orthodontic treatment. Tooth loss is often accompanied by alveolar bone development disorders, resulting in significant atrophy of the alveolar ridge and lack of posterior tooth support.

Disease treatment

1. Early diagnosis of missing teeth allows for early multidisciplinary collaboration to determine treatment options. Patients should start treatment at a young age. The patient and parents should be informed of the treatment situation and purpose before treatment.

2. The choice of treatment generally depends on the severity of the congenital missing teeth. A range of treatments are required involving pediatric, orthodontic and prosthodontic specialists.

3. When making a treatment plan, many influencing factors should be considered, including: patient age, number and health of remaining teeth in the mouth, number of missing teeth, caries status, health of supporting tissues, jaw relationship and recumbent jaw space, etc.

4. The following treatment approaches may be considered in treatment planning and play an important role in the overall management of congenitally missing teeth.

(1) If crowding is expected, deciduous teeth should be removed promptly to allow the space to close naturally, thus reducing the need for subsequent interventional treatment;

(2) Ectopic teeth may require surgical exposure to promote eruption and orthodontic traction;

(3) Resection of the thick frenulum and crown lengthening will facilitate the expected fixed restoration in the future;

(4) To facilitate orthodontic and restorative treatment, low-positioned deciduous teeth need to be extracted;

(5) Orthodontic treatment includes the application of functional appliances, removable or fixed appliances to close or redistribute the space.

5. Resin-bonded fixed partial dentures and bone-integrated implants are used in patients with mild to moderate congenital hypodontia. Treatment planning includes careful consideration of the patient's oral hygiene, socioeconomic background, and compliance. Preoperative orthodontic treatment is required to align the teeth, create appropriate spacing and establish a prediction of the ideal axial inclination of the adjacent teeth next to the implant.