The mouth does not open wide
Difficulty biting a piece of food or opening the mouth wide.
CONDITION / FACE
Microstoma: narrowed mouth.
Microstoma is a narrowing of the mouth opening, which makes it difficult to open the mouth wide: it prevents eating, speaking, brushing teeth and treatment at the dentist. Most often, it is caused by scars after burns, scleroderma or surgery on the lips.
CONCEPTUAL VISUALIZATION- What it is
- The mouth is narrowed: it is difficult to open the mouth wide, the corners of the mouth are tightened.
- Causes
- Scars after burns around the mouth, systemic scleroderma, surgeries on the lips and cheeks.
- What prevents
- Eating, talking, brushing teeth, treating them at the dentist; the facial expression changes.
- Who treats it
- Plastic surgeon; with scleroderma - together with a rheumatologist; teeth - a dentist.
01 / WHAT IS ITWhat is
What is
microstoma
Microstoma is a condition where the mouth opening is smaller than it should be, and because of this the functions suffer: it is difficult to eat, pronounce words, take care of the teeth, facial expression changes. The mouth plays a key role in speech, facial expressions and eating, so even a small narrowing can be felt every day.
Most often, the mouth is narrowed by scars: after a burn, the tissues near the corners of the mouth tighten. Another common cause is systemic scleroderma, a disease in which the skin on the face hardens and thickens. Narrowing also occurs after operations on the lips, when the tissues of the lips are stitched together after the removal of the tumor.
There is no single "correct" mouth size, so the doctor evaluates not only millimeters, but also what exactly is bothering you. Microstoma is a rare condition, and the treatment plan is made individually.
This is general information. The doctor will tell you what will suit you after the examination.
02 / SIGNSHow
How
microstoma presents.
Usually, the narrowing grows gradually, and a person notices it when it becomes difficult to bite, brush teeth or undergo dental treatment.
Tightened corners of the mouth
The corners of the mouth are tightened with a scar, the lips are thin and tense, the smile has become narrower.
Food and language
It is more difficult to chew and swallow, and it is more difficult to pronounce some sounds.
Teeth
It is difficult to clean the teeth, especially the back teeth, and to treat them at the dentist.
mood
Due to appearance and difficulties with food, a person avoids communication, loses confidence.
03 / REASONSWhy the mouth?
Why the mouth?
narrows
Whether splints and exercises will help and which operation is chosen depends on the cause.
Burns around the mouth
Burns of the lips and skin around the mouth—thermal, chemical, or electric—heal with a scar that tightens the corners of the mouth.
Scars after facial burnsIngestion of caustic substances
A mouth burn with acid or alkali scars the tissues both outside and inside the mouth; it affects children especially hard.
Scleroderma
In systemic scleroderma, microstoma occurs frequently: in a study of 131 patients, it occurred in 56.5%. The mouth narrows due to tightening of the facial skin.
Lip operations
When the lip is restored with the own tissues of the lips and cheeks after tumor removal, the mouth may narrow; therefore, for large defects, flaps from other parts of the body are used.
Defects and deformations of the lipsRemoval of skin cancer
Repeated removals of skin tumors near the mouth can also narrow the mouth.
Lip cancer
04 / SEEK MEDICAL ADVICE
When to seek medical advice?
Microstoma usually grows gradually and does not require emergency care. Another matter is a fresh burn or poisoning: then help is needed immediately.
103 immediately if:
- a fresh burn of the face or lips;
- acid, other chemical or electric burn;
- a child or an adult swallowed household chemicals or other harmful substance - do not induce vomiting;
- it is very difficult to breathe: a person cannot utter words, is suffocating;
- the person fainted.
Do not delay a visit to the doctor:
On the same day: it became difficult to swallow, you cough or choke while eating, food gets stuck in your throat, or you have shortness of breath after eating. In the coming days: the burn around the mouth heals - see a doctor before the scar tightens the mouth; your mouth opens less and less or you lose weight because you cannot eat normally. Planned: the narrowing is long-standing and stable, but interferes with eating, speaking, brushing or treating teeth.
05 / DIAGNOSTICSAs defined,
As defined,
that interferes
- Conversation
When did the narrowing appear and what caused it: burn, scleroderma, surgery on the lips; how it changed.
- Measurements
The distance between the corners of the mouth and between the teeth with the mouth as wide as possible — before and after treatment.
- Examination of the mouth
Is the scar only on the skin or on the mucous membrane of the cheek; condition of gums and teeth; how many healthy tissues are nearby.
- Other doctors
In case of scleroderma - the conclusion of a rheumatologist; if necessary, a dentist.
06 / TREATMENTHow we treat
How we treat
microstoma
The goal is to expand the mouth and preserve its functions: food, speech, facial expressions. With a mild narrowing, help without surgery is limited, and surgery gives a better result. The method is chosen based on the severity of the narrowing and how much healthy tissue there is around the mouth.
01
Without surgery
At the early stage after a burn and with scleroderma.
- Mouth splints
- Special splints stretch the corners of the mouth so that the scar does not tighten them. In a burn center, among 83 patients with burns around the mouth who were given such a splint, only one required surgery, provided they were worn diligently. There is no consensus on which splint to wear and how much - it is made for each patient.
- Exercises
- In scleroderma, in a randomized trial of 56 patients, home facial exercises twice a day for a month increased mouth opening. But in another study, in a systematic review, additional oral care exercises did not increase disclosure.
- Scleroderma
- The disease itself is treated by a rheumatologist. For the mouth, physical therapy, injections, and medications are often described in studies; there is no evidence that any one method works for a long time, so methods are combined.
02
Surgery
When tires and exercises are not enough.
- Widening of the corners of the mouth
- Commissuroplasty: the scar in the corner of the mouth is dissected or excised, and the new corner is lined with buccal mucosa. In a series of 5 patients, the opening of the mouth increased by an average of 6.0 mm, and the distance between the corners of the mouth - by 7.2 mm.
- Three groups of methods
- A review of 28 studies described 10 techniques: skin or mucosal grafting, local flaps, and tissue transplantation from other parts of the body.
- Large scars
- The scar is dissected, the mucous membrane is restored from the inside with a skin graft, and a splint is worn after the operation. In a series of 11 patients who ingested a caustic substance, the distance between the corners of the mouth increased from 17.3 to 34.0 mm on average.
- Lipofilling
- In scleroderma, one's own fat is injected around the mouth — this is the most frequent operation in research. The review names lipofilling, botulinum toxin injections, and UVA1 phototherapy as the methods with the most potential, but none have yet been proven to work long-term.
03
Food and teeth
Daily life with microstoma.
- Food
- Softer food, thickened drinks, special spoons and cups. If it is difficult to swallow or you are losing weight, a speech therapist and a nutritionist will help.
- Oral hygiene
- With scleroderma, in addition to narrowing of the mouth, there are dry mouth, gum disease and tooth loss. Regular oral care and dental check-ups are important: in studies, a comprehensive care program improved oral hygiene.
- Dentist
- Tell the dentist about the microstoma in advance. With scleroderma, the dentist is often the first to notice changes in the mouth.
07 / AT THE VALIKHNOVSKYI INSTITUTE
How
How
we treat it.
Microstoma at Dr. Valikhnovskyi's Institute of Surgery is treated in the "New face" direction, and the effects of burns are treated in the "Reconstruction after burns" direction. The clinic is responsible for the surgical part; scleroderma is managed by a rheumatologist, teeth by a dentist.
CLINIC SERVICE
A new face
Form, symmetry, facial expressions and functions after injuries, wounds, burns, removal of tumors and congenital changes.
View service
What we do for this condition
- Dissection of scar tissue and Z-plasty — a scar that tightens the lips and corners of the mouth, dissect or cut out and redistribute the tissues with local flaps.
- Skin grafting — the lack of tissues is closed with a skin graft.
- Flaps from the face — perforating flaps and flaps of adjacent areas close the defect without distorting the lines of the mouth.
- Radial forearm flap — thin flexible flap for restoration of lips, cheeks and oral mucosa in case of large defects.
- Expander — stretched nearby healthy skin replaces the scar when local tissues are lacking.
- Lipofilling - own fat - for the volume and softness of scar tissue.
- Tires and rehabilitation — after operations on cicatricial contractures — splints and classes with a rehabilitator so that the cicatricial scar does not contract again.
Rostislav Valikhnovskyi
Plastic surgeon, candidate of medical sciences, founder of Dr. Valikhnovskyi Institute of Surgery.
How treatment works with us
- Photo onlineSend a photo of your face directly and from the side with your mouth closed and as wide as possible.
- ConsultationExamination of the mouth, measurement of the opening, assessment of scars and healthy tissues nearby.
- PlanWhat can be done without surgery, and what needs surgery, and in what sequence.
- TreatmentDissection of the scar, flaps or tissue transplantation - depending on the cause and severity.
- RecoverySplints and exercises after surgery, control examinations.
08 / QUESTIONS AND ANSWERSCommon
Common
questions
Short answers. What is right for you, the doctor will tell you during the consultation.
Is it possible to enlarge the mouth without surgery?
Sometimes partially: splints and exercises help, especially in the early stage after a burn and with scleroderma. But with an already formed scar, surgery usually gives the best result.
What is commissuroplasty?
An operation to widen the corners of the mouth: the scar in the corner is dissected or excised, and the new corner is lined with buccal mucosa.
What to do after a child burns around the mouth?
First, the burn itself is treated. Even before complete healing, ask the doctor about a mouth splint: they try to prevent microstoma in children as early as possible.
Is it possible to operate with scleroderma?
Yes, but the disease continues, so the treatment is combined: a rheumatologist treats scleroderma, and for the mouth, exercises, injections and operations are used, more often - lipofilling.
How to eat if the mouth opens little?
Softer food, small pieces, thickened drinks, special spoons and cups help. If you are losing weight or choking, consult a doctor - a speech therapist or nutritionist will advise.
How to take care of teeth?
Regularly, even if it is difficult, and go for examinations to the dentist. With scleroderma, the risk of gum disease and tooth loss is higher.
Do I need to wear a splint after surgery?
After surgery, a splint and exercises are often prescribed to prevent the scar from tightening the mouth again. The doctor will tell you whether you need a splint and how long to wear it.
Sources
17 sources · reviews, research and NHSshowCollapse
- Surgical Management of Microstomia: A Comprehensive Review of Treatment OptionsJPRAS Open, 2025doi:10.1016/j.jpra.2025.03.002 ↗
- Prevention and treatment of microstomiaArchives of Craniofacial Surgery, 2024doi:10.7181/acfs.2024.00276 ↗
- Reconstruction of microstomia considering their functional statusArchives of Craniofacial Surgery, 2020doi:10.7181/acfs.2020.00220 ↗
- Integrated surgical approaches for caustic ingestion-induced microstomiaBurns, 2026doi:10.1016/j.burns.2026.107911 ↗
- Lip and perioral reconstructionClinics in Plastic Surgery, 2005doi:10.1016/j.cps.2005.02.007 ↗
- Pediatric facial burnsJournal of Craniofacial Surgery, 2008doi:10.1097/SCS.0b013e318175f42f ↗
- The microstomia prevention appliance: 14 years of clinical experienceJournal of Burn Care & Rehabilitation, 1988doi:10.1097/00004630-198801000-00023 ↗
- Managing Long-term Orofacial Contractures and Microstomia Through Intraoral StretchingJournal of Burn Care & Research, 2024doi:10.1093/jbcr/irae123 ↗
- Review of the Current Medical and Surgical Treatment Options for Microstomia in Patients With SclerodermaDermatologic Surgery, 2021doi:10.1097/DSS.0000000000002995 ↗
- Restoring Mouth Opening in Systemic Sclerosis: A Scoping Review of InterventionsOral Diseases, 2026doi:10.1111/odi.70451 ↗
- Microstomia is associated with functional impairment and is a poor prognostic factor in systemic sclerosisBMC Oral Health, 2024doi:10.1186/s12903-024-05178-6 ↗
- The effect of a home-based orofacial exercise program on oral aperture of patients with systemic sclerosis: A single-blind prospective randomized controlled trialArchives of Rheumatology, 2021doi:10.46497/ArchRheumatol.2021.8295 ↗
- Effectiveness of Nonpharmacologic Interventions in Systemic Sclerosis: A Systematic ReviewArthritis Care & Research, 2015doi:10.1002/acr.22595 ↗
- Orofacial Complications of the Connective Tissue Disease Systemic SclerosisJournal of Dental Research, 2024doi:10.1177/00220345241249408 ↗
- Burns and scaldsNHS, 2026nhs.uk/conditions/burns-and-scalds ↗
- PoisoningNHS, 2025nhs.uk/conditions/poisoning ↗
- Dysphagia (swallowing problems)NHS, 2023nhs.uk/symptoms/swallowing-problems-dysphagia ↗
The figures on the page are from these sources.
The mouth opens
less and less?
Send a photo of your face with your mouth closed and open. The doctor will tell you what caused the narrowing and how you can help.