Clinical case
A 14-year-old patient attends because of spacing in the upper anterior region. The maxillary lateral incisors are absent clinically. The maxillary canines have erupted close to the central incisors. A dental panoramic radiograph confirms absence of both permanent maxillary lateral incisors, with no evidence of impaction or previous extraction.
Pathophysiology
Hypodontia results from failure of initiation or early development of the dental lamina and tooth germ. It may occur as an isolated inherited trait or as part of a wider syndrome.
The most commonly missing permanent teeth are:
Third molars
Second premolars
Maxillary lateral incisors
Epidemiology and Risk Factors
Non-modifiable | Modifiable |
|---|---|
Family history | No modifiable risk factors |
Syndromic associations (Down syndrome, cleft lip/palate and ectodermal dysplasia) |
Clinical Features
Hypodontia is the absence of 1-5 developing teeth (excluding wisdom teeth). 6 or more absent teeth is known as oligodontia.
Symptoms | Signs |
|---|---|
Gaps between teeth | Clinically missing primary teeth |
Retained primary teeth | Canine substitution (canine erupts into lateral incisor space) |
Infraoccluded primary molar | |
Altered occlusion |
Investigations
Primary investigations:
Full dental and medical history
Family history
Clinical examination and charting
Radiographs: OPG to confirm absent tooth germs and assess full dentition
Gold standard investigation:
Diagnosis is made by clinical examination plus radiographic confirmation that the tooth germ is absent. An OPG is usually the key investigation because it assesses both arches and the developing dentition.