22q11 Deletion (DiGeorge Syndrome) and Orthodontics UK

What is 22q11.2 deletion syndrome?

22q11.2 deletion syndrome results from a small deletion on chromosome 22 at the q11.2 locus. It is one of the most common chromosomal microdeletions in humans, occurring in approximately 1 in 2,000 to 4,000 live births. The syndrome is known by several names — DiGeorge syndrome, velocardiofacial syndrome (VCFS), conotruncal anomaly face syndrome, and Shprintzen syndrome — all of which arise from the same underlying genetic deletion, though clinical expression varies widely between individuals. Features of the syndrome may include congenital heart defects (particularly conotruncal malformations such as tetralogy of Fallot, truncus arteriosus, and interrupted aortic arch), velopharyngeal insufficiency (VPI) causing a nasal speech quality, hypocalcaemia from parathyroid hypoplasia, T-cell immune deficiency from thymic hypoplasia, learning difficulties, and a characteristic facial appearance including a long face, tubular nose, and small mouth. Dental and orthodontic findings are consistently present and well documented in the literature.

Dental findings in 22q11.2 deletion

Children with 22q11.2 deletion have a significantly higher prevalence of dental anomalies than the general population. Hypodontia — one or more congenitally missing permanent teeth — is common, with the lower second premolars and upper lateral incisors most frequently absent. Missing upper lateral incisors are particularly relevant to orthodontic planning as they affect both aesthetics and the space balance in the arch. Delayed eruption of permanent teeth is frequently reported. Enamel hypoplasia — abnormal development of tooth enamel producing pits, grooves, or areas of reduced mineralisation — affects a substantial proportion of patients and increases caries susceptibility. Microdontia (small teeth), taurodontism (enlarged pulp chambers), and root anomalies have also been described. The combination of hypodontia, enamel hypoplasia, and immune compromise creates a challenging oral environment that requires careful hygiene management before orthodontic forces are applied.

Velopharyngeal insufficiency and orthodontic planning

Velopharyngeal insufficiency (VPI) — the inability of the soft palate to close fully against the posterior pharyngeal wall during speech — is one of the most functionally significant features of 22q11.2 deletion. It causes hypernasality (a nasal quality to speech), nasal emission of air during consonant production, and compensatory articulation patterns. VPI is present in around 70 to 90 percent of individuals with the deletion. Orthodontic and surgical interventions that alter the dimensions of the palate, nasopharynx, or velopharyngeal space carry particular risk in this population. Maxillary expansion — either via removable appliances or surgically assisted — can worsen VPI by widening the space the soft palate must close off. Any expansion treatment should be planned in consultation with a speech and language therapist and a surgeon experienced in VPI management. Similarly, pharyngeal flap surgery — a common VPI treatment — must be coordinated with any planned orthognathic surgery to avoid compromise of the surgical access or the vascular pedicle.

Cardiac conditions and antibiotic prophylaxis

Approximately 50 to 75 percent of individuals with 22q11.2 deletion have congenital heart defects. The most common conotruncal malformations require surgical correction in infancy or early childhood. By the time orthodontic treatment is being considered, many patients will have had cardiac surgery and may have residual defects, prosthetic patches, or mechanical valves. In the UK, NICE guideline NG208 does not recommend routine antibiotic prophylaxis before dental or orthodontic procedures even for high-risk cardiac conditions. However, patients with residual defects, prosthetic material, or who have received a heart transplant with valve regurgitation should have their cardiac status reviewed in liaison with their cardiologist before orthodontic treatment begins. Any orthodontic procedure that is likely to cause significant bacteraemia — such as tooth extraction or surgical TAD placement — warrants a joint decision on prophylaxis documented in the clinical records. The orthodontist should be informed of the full cardiac history at the initial consultation.

T-cell immune deficiency and infection risk

The thymus gland is hypoplastic or aplastic in approximately 75 to 85 percent of patients with 22q11.2 deletion, resulting in reduced T-cell production and a degree of cellular immune deficiency. In most patients, the immunodeficiency is partial rather than complete and compatible with a near-normal immune response. However, patients at the more severe end of the spectrum are more susceptible to viral and bacterial infections, and may have impaired healing responses. In the orthodontic context, this means that any procedure carrying infection risk — extractions, TAD placement, bonding procedures in the presence of active periodontal inflammation — should be carried out with appropriate infection control and monitoring. Oral hygiene standards are particularly important in immunocompromised patients; orthodontic treatment should not begin until plaque control is excellent. Patients on immunosuppressive medications as part of cardiac transplant management require specific precautions discussed with the transplant team.

Calcium dysregulation and bone effects

Parathyroid gland hypoplasia is common in 22q11.2 deletion and produces hypoparathyroidism with resultant hypocalcaemia (low blood calcium). Hypocalcaemia in infancy may cause seizures and cardiac arrhythmias, but in older children and adults the calcium level is usually controlled with supplementation. Chronic hypocalcaemia — even when partially corrected — can affect bone mineralisation and tooth development. Orthodontic tooth movement relies on osteoclastic bone remodelling, and patients with reduced bone density or abnormal bone mineralisation may experience different rates or quality of tooth movement compared with unaffected patients. Enamel hypoplasia and hypomineralisation further complicate treatment, as hypomineralised enamel may be more susceptible to demineralisation around brackets and less amenable to IPR. The clinical implication is that treatment may need to be slower, forces should be light, and calcium status should be stable before treatment begins.

Psychiatric and neurodevelopmental considerations

22q11.2 deletion is associated with increased rates of learning difficulties, attention deficit hyperactivity disorder (ADHD), anxiety disorders, and psychotic disorders including schizophrenia — the risk of developing schizophrenia or schizophrenia-spectrum disorder is approximately 25 percent in adulthood, significantly higher than the general population. In adolescence, when much orthodontic treatment is planned, patients may be navigating neurodevelopmental difficulties, anxiety, or early psychiatric symptoms. Orthodontic appointments should be adapted for patients with anxiety or processing difficulties: clear explanations, consistent clinicians, predictable appointment structures, and written or visual aids where helpful. Compliance with aligner wear or appliance instructions may be challenging for patients with ADHD or learning difficulties, and fixed appliances may be more appropriate in these cases. Close liaison with the patient's educational or mental health support team is recommended where neurodevelopmental needs are significant.

Specialist treatment pathway and multidisciplinary care

Because of the complexity and range of co-existing conditions in 22q11.2 deletion, orthodontic treatment is best managed within a specialist multidisciplinary team rather than in a standard orthodontic practice. In the UK, recognised craniofacial units and cleft lip and palate networks have the clinical infrastructure to coordinate care between orthodontists, oral and maxillofacial surgeons, speech and language therapists, geneticists, cardiologists, immunologists, and clinical psychologists. Regional specialist centres accepting NHS referrals can be identified through the patient's paediatrician or clinical geneticist. The Cleft Lip and Palate Association (CLAPA) and 22q11 UK (a patient support organisation) can provide additional guidance on UK services and what to ask when seeking referral. Parents of newly diagnosed children should ideally be referred to a specialist dental and orthodontic service at the point of diagnosis so that early dental surveillance and interceptive orthodontic planning can begin before significant problems develop.

Useful related pages

This guide is for general information only. It is not a diagnosis, treatment plan, or substitute for advice from a registered dentist or orthodontist.