Orthodontic treatment has traditionally been regarded as a teenage rite of passage. Some benefits of treatment are obvious (straighter teeth), while others are less visible (improved bite and jaw positions). In general, orthodontic treatment can begin when all the permanent teeth have erupted (11 to 12 years old). However, there is a group of children who should consider starting treatment at a younger age.

Permanent teeth generally begin to erupt at the age of six to seven years, and it is during this time that orthodontic problems become apparent. The Association of Orthodontists (Singapore) strongly recommends that all children undergo orthodontic screening by seven to eight years. Both the medical and dental practitioners play crucial roles in the early identification and diagnosis of orthodontic problems, and in making timely referrals to the orthodontist for further assessment and intervention.

It is precisely this group of young patients, as early as seven to eight years, who will benefit the most from early orthodontic treatment. This is because most children’s deciduous teeth are changing, their permanent teeth developing and their jaws still growing. During this period of time, certain conditions and problems may be easier to address through interceptive orthodontics1.

Tertiary assessment and intervention are valuable in orthodontic cases, where the timing of intervention and long-term planning of orthodontic treatment are critical for an optimal outcome. At KK Women’s and Children’s Hospital (KKH), the Dental Service provides comprehensive care from childhood to adulthood.

The main goals of early orthodontic intervention are early correction and prevention to achieve a functional and stable bite. Often, the child wears a type of oral appliance for six to 12 months. It is important to note that children who receive interceptive orthodontics generally still require braces later on in life. However, early intervention at a younger age may shorten or simplify future correction during their second phase of orthodontic treatment.

From a psychosocial perspective, early orthodontic treatment significantly improves patients’ self-concept and self-esteem. This early increase in self-esteem may still be important for children, especially if the child had been repeatedly teased or bullied in school because of their teeth. This article aims to explore and highlight the current best practice recommendations for the following commonly-seen orthodontic problems:


Class I malocclusion

The Class I malocclusion (Figure 1) is the most commonly seen malocclusion in Singapore, with a prevalence of 48.1 per cent. Generally, there is minimal skeletal involvement and the condition is easily treated by orthodontics only. Such patients seldom require interceptive treatment and are routinely seen at KKH when more of their permanent teeth have erupted.


Class II malocclusion

The second most common malocclusion in Singapore is the Class II division 1 malocclusion with proclined upper incisors and an increased overjet (Figure 2), with a local prevalence of 26.3 per cent2.

Protruding upper incisors have been associated with a high incidence of dental trauma. In addition, the small size of the child’s mandible often causes the lower teeth to bite into the upper palatal gingivae. This may cause gingival recession or pain to the palatal tissue. Left untreated, the bite may worsen, eventually requiring surgical correction. The prolonged gingival trauma on the palate may also cause irreversible gum disease.

Early treatment with a functional appliance (Figure 3) or headgear has been shown to reduce new incidences of incisal trauma by 33 to 41 per cent3. Interceptive treatment is often able to limit the damage in growing patients, allowing the periodontal tissues to spontaneously improve once the source of trauma is removed.

Growth modification should ideally be timed when there is still potential for growth, ideally during the adolescent growth spurt.

Generally, this treatment can be initiated at about 11 to 12 years in females, before menarche, and 12 to 13 years in males. The growth of the mandible can be redirected in a forward direction by active posturing of the mandible. As the child continues to grow, natural musculoskeletal changes will lead to remodelling of the temporomandibular joint and the development of the mandible in its improved position.


Class III malocclusion

The Class III malocclusion (Figure 4) is more prevalent in Singapore compared with Caucasian populations, and is the third most common malocclusion with a 22.4 per cent prevalence locally2.

Patients with Class III malocclusions often experience functional impairment, being unable to bite with their front teeth. In less severe cases, they are able to touch their front teeth together, resulting in a posterior open bite. In order to function, they temporarily posture their mandible forward, which over time may result in remodelling of the temporomandibular joint in its new forward position. Left untreated, this may cause the patient to develop more severe bite and jaw problems.

Some children with a small maxilla can benefit from facemask protraction therapy to pull the maxilla forward whilst they are young and the circummaxillary sutures are not completely fused. This is often initiated at eight to 10 years in males and females.

The force of mandibular growth cannot be fully resisted if the patient has an excessively large mandible; the patient may still outgrow the prescribed treatment and develop a reverse overjet again later on during the secondary growth spurt. However, there is supporting evidence indicating that early facemask protraction therapy can reduce the severity of the skeletal discrepancy and may obviate the need for orthognathic surgery in the future.


Anterior crossbite

An anterior crossbite occurs when an upper tooth is trapped behind the lower tooth, and the lower teeth bite ahead of the teeth (Figure 5). Left untreated, this may lead to wear and fractures of the anterior teeth, as well as gingival recession and mobility of the incisor teeth.

In the long term, an untreated anterior crossbite could affect the development of the maxilla, and cause functional displacement and asymmetry of the mandible, poor eruption of teeth and temporomandibular joint disorders.

Fixed orthodontic treatment and upper removable appliances are commonly used to correct the crossbites, and most crossbites in a growing child can be corrected within six months of treatment.


Anterior open bite

The anterior open bite (AOB) occurs when the anterior teeth are unable to meet, despite the posterior teeth meeting together (Figure 6). With the anterior teeth rendered ineffective for chewing, the posterior teeth bear more of the chewing load and are worn down at a quicker rate. This is a less common condition, with an estimated four per cent prevalence in Singapore.

AOB can also be caused by habits such as having the tongue protruding and pushing against the front teeth, or non-nutritive sucking. It can also develop as a result of excessive downward vertical growth of the mandible. In younger children, prolonged duration of the thumb-sucking habit causes a more severe malocclusion to develop4. Patient compliance and cooperation is essential in eliminating the causal habit; the child must first be motivated to terminate these habits before the clinician intervenes.

If the habitual cause of AOB is addressed early, the open bite may close spontaneously. However, if left untreated into late adolescence or even adulthood, AOB correction can be complex, time consuming and more costly. In more severe cases, orthognathic jaw surgery may be required to correct the condition.

Infrequently, a sudden and rapid development of an anterior open bite may also be attributed to condylar resorption of the temporomandibular joint, such as juvenile idiopathic condylar resorption, which is more commonly seen in adolescent females.


Teeth eruption problems and impaction

Failure of eruption of the maxillary permanent incisor teeth (Figure 7) usually presents in the mixed dentition stage and is often noticed between seven to nine years. This often occurs secondary to space loss, obstruction or trauma5. The anterior maxilla segment is also prone to development of extra or malformed teeth, which may impede the eruption of the permanent teeth in approximately 28 to 60 per cent of cases6.  

Missing and unerupted maxillary incisors can be regarded as unattractive and can have a negative impact on facial and dental aesthetics, which may then affect self-esteem and social interaction in an adolescent patient7. In addition, permanent teeth stuck under the gums may sometimes result in the development of a cyst, or injury due to pressure against adjacent teeth roots.


Delayed eruption of the permanent maxillary incisor teeth can be considered in the following circumstances:

  • Eruption of the corresponding contralateral incisor occurring more than six months earlier
  • Failure of eruption of the maxillary incisors more than one year after the eruption of the mandibular incisors
  • A significant deviation from the normal teeth eruption sequence


Management of an unerupted tooth may involve one or a combination of the following:

  • Removal of the physical obstruction
  • Creation of space with fixed orthodontic treatment (Figure 8)
  • Surgical intervention to apply traction to the unerupted tooth


In summary:

  • The child can be referred to the orthodontist at seven to eight years, when the adult teeth are starting to erupt.
  • Early orthodontic treatment can greatly benefit some patients, when correctly indicated.

In complex cases, early orthodontic treatment is crucial, as it makes future treatment more straightforward when the child is older.


Refer a patient

Healthcare professionals can refer patients to the paediatric Dental Service at KKH for assessment, by contacting the hospital at +65 6294 4050.


​Dr Goh Ai Wei, Dental Registrar, Dental Service, KK Women’s and Children’s Hospital

Dr Goh Aik Wei works closely with cross-disciplinary teams to provide orthodontic treatment for patients with complex medical conditions, special needs, trauma, or needing early interceptive treatment. Dr Goh completed her undergraduate and postgraduate orthodontic training at the National University of Singapore, and was awarded Membership in Orthodontics from the Royal College of Surgeons in Edinburgh in 2017.

Dr Koo Chieh Shen, Dental Registrar, Dental Service, KK Women’s and Children’s Hospital

Dr Koo Chieh Shen acquired his degree in dentistry at the National University of Singapore in 2011. He completed a three-year specialist Orthodontic training programme at the Eastman Dental Institute in London and was awarded Membership in Orthodontics from the Royal College of Surgeons in Edinburgh in 2016. Dr Koo has particular interests in interceptive orthodontics, and cleft and craniofacial anomalies.

Dr Chng Chai Kiat, Senior Consultant, Dental Service, KK Women’s and Children’s Hospital

Chief Dental Officer, Ministry of Health, and a senior consultant with the Dental Service at KKH, Dr Chng Chai Kiat treats a wide array of orthodontic cases, and is known for ‘Surgery First’ Ortho-orthognathic management and treatment for patients with cleft and cranio-facial problems.

With a keen interest in clinical research, particularly in the field of orthodontics, Dr Chng’s research interests include biology of tooth movement, 3D imaging and the aetiology, genetics and prevention of cleft deformity. Dr Chng is also Director, Clinical Head KKH, Clinical Service, SingHealth Duke-NUS Oral Health Academic Clinical Program.



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