Acromegaly and Orthodontics UK

How acromegaly affects the jaw and bite

Acromegaly is caused by a growth-hormone-secreting pituitary tumour producing excess IGF-1, which drives continued bone growth in adults. Unlike in childhood gigantism, the skull base is fused in adults, so the excess GH cannot increase height — instead it causes progressive enlargement of peripheral bones including the mandible (lower jaw), orbital ridges, hands, and feet. The mandible grows predominantly at the condyles (the jaw joints), driving the lower jaw progressively forward and downward. This creates a worsening Class III malocclusion (underbite) over months to years. Associated dental changes include widened spacing between teeth (diastema) as the dental arch expands, anterior open bite as the lower jaw grows downward, and macroglossia (enlarged tongue) which causes additional spacing and can push teeth forward. The extent of skeletal and dental change depends on how long acromegaly was active before diagnosis and treatment, and on the degree of GH excess during that period.

Why GH control must come before orthodontic treatment

Attempting orthodontic correction — or orthognathic surgery — before acromegaly is biochemically controlled is unlikely to produce a stable result and may be directly harmful. If GH levels remain elevated, the mandible will continue to grow after surgical correction, causing relapse of the underbite and failure of the orthodontic outcome. Most specialist centres will not proceed with definitive orthodontic-surgical treatment until: IGF-1 levels have normalised (typically to age-adjusted reference ranges), GH suppression has been confirmed on a glucose tolerance test, and levels have been stable for at least 12 months. First-line acromegaly treatments include transsphenoidal pituitary surgery to remove the adenoma, somatostatin analogues (octreotide, lanreotide) to suppress GH secretion, and pegvisomant (a GH receptor antagonist). Your endocrinologist will confirm when biochemical control is sufficient to proceed with jaw treatment. Do not skip this step — relapse after jaw surgery in patients with uncontrolled acromegaly is well documented.

Class III malocclusion and orthognathic surgery planning

The degree of jaw discrepancy in acromegaly patients is often significant — more severe than the typical developmental Class III malocclusion seen in non-acromegalic patients. Mild cases with limited skeletal discrepancy may be managed with orthodontics alone (dental compensation), but most acromegaly patients with established malocclusion require combined orthodontic and orthognathic (jaw) surgery to achieve a functional and stable result. Planning involves: cephalometric analysis (skull X-rays measuring jaw relationship and tooth angulations), dental study models and digital scans, CBCT (cone beam CT) imaging in complex cases, and surgical simulation. The surgical options include bilateral sagittal split osteotomy (BSSO) of the mandible to set the lower jaw back, or bimaxillary surgery repositioning both jaws if the upper jaw is also affected. The orthodontic phase before surgery (pre-surgical orthodontics) typically takes 12 to 18 months and involves aligning teeth to their correct positions within each jaw so that after surgery the teeth meet correctly. Post-surgical orthodontic finishing then refines the result.

Macroglossia and its effect on orthodontic stability

Macroglossia — an enlarged tongue — is a direct effect of IGF-1 excess in acromegaly and affects both the position of teeth and the long-term stability of orthodontic and surgical results. An enlarged tongue creates outward pressure on the teeth, particularly the lower incisors and the anterior arches. This can cause: persistent or recurrent anterior spacing, difficulty closing the lips, anterior open bite tendency, and speech effects. If macroglossia is significant and persistent after GH normalisation — some reduction in tongue size occurs as soft tissues respond to normalised hormone levels — it must be factored into treatment planning. In severe cases, surgical tongue reduction (reduction glossoplasty) is occasionally considered before or alongside orthognathic surgery to improve stability of the dental correction. The decision involves a multidisciplinary team including an oral and maxillofacial surgeon and speech and language therapist.

Condylar changes and temporomandibular joint considerations

Acromegaly causes changes not only in the mandibular body but at the condyles — the jaw joints. Condylar enlargement and remodelling can cause or worsen temporomandibular joint (TMJ) dysfunction, joint pain, and asymmetric jaw growth. The TMJ must be assessed carefully before orthognathic surgery planning. Active condylar remodelling (growth continuing) must be ruled out before jaw surgery proceeds, since unpredictable condylar changes after surgery can cause relapse. Serial condylar imaging — typically comparing CBCT scans at 6 to 12 month intervals — is used to confirm stability. Joint pain and limited mouth opening are also relevant to treatment planning, as these may affect impression taking, brace fitting, and surgical access. If significant TMJ dysfunction is present, it may need to be managed (possibly with occlusal splint therapy or physiotherapy) prior to definitive orthodontic-surgical treatment.

NHS access and specialist referral pathways

Acromegaly is a rare disease managed within NHS specialist endocrinology services. The jaw and dental consequences are typically managed through NHS craniofacial or oral and maxillofacial surgery (OMFS) departments at teaching hospitals. NHS orthodontic and surgical treatment for significant malocclusion caused by acromegaly should be accessible via specialist referral — the clinical case is strong, given that the malocclusion is caused by a recognised pathological process. The pathway typically involves: your endocrinologist confirming biochemical control and referring to OMFS, OMFS assessment and treatment planning including orthodontic liaison, an NHS or combined NHS/private orthodontist managing the pre-surgical orthodontic phase, and OMFS performing the orthognathic surgery. Waiting times at specialist centres can be lengthy. If you are considering private treatment, ensure the team has experience with syndromic jaw cases — not all orthognathic surgeons regularly manage acromegaly-related jaw discrepancies. Ask specifically about their experience with this condition.

What patients with acromegaly can do now

If you have acromegaly and are concerned about your bite or jaw, the most important immediate steps are: confirm with your endocrinologist that your GH and IGF-1 levels are controlled and stable, ask for a referral to an oral and maxillofacial surgeon or specialist orthodontist with craniofacial experience, document your jaw changes over time if possible (photographs and models from previous dental visits), and ask your GDP to monitor your bite and flag any progressive changes. A photo assessment through Virtual Consultant Online can provide an initial clinician view of your bite and jaw from photos before you navigate specialist referral — this can help you understand what level of intervention is likely needed and prepare better questions for your specialist appointments.

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.