What Is This Condition?
An asymmetric smile refers to a condition in which the right and left sides of the face do not appear balanced during smiling. Different elevations of the lip corners, mismatch between the dental midline and facial midline, a smile that appears shifted to one side, or uneven gum display between the two sides are all different manifestations of smile asymmetry. An asymmetric smile is not a disease on its own; it is an aesthetic and sometimes functional finding. One important fact should be emphasized: absolute symmetry is rare in nature. Most healthy individuals have some degree of facial asymmetry, and these subtle asymmetries are often considered part of a person’s individuality — in some cases even adding character to the face. However, when asymmetry becomes pronounced, it may create aesthetic concerns, affect self-confidence, and in some cases be associated with functional problems such as chewing difficulties, speech issues, or TMJ disorders.
Facial Asymmetry vs. Smile Asymmetry
In clinical evaluation, these two concepts must be distinguished because the treatment approach depends on the underlying type of asymmetry.
Static Facial Asymmetry
The face appears asymmetric even at rest. This is usually a structural condition related to skeletal or soft tissue differences. More comprehensive treatments such as orthognathic surgery may be required.
Dynamic Asymmetric Smile
The face appears symmetrical at rest but becomes asymmetric during smiling. This is usually related to muscle activity or dental/gingival factors and can often be managed with less invasive treatments.
In some patients, both conditions coexist, requiring a more comprehensive multidisciplinary evaluation.
Components of an Asymmetric Smile
The symmetry of a smile depends on the harmony of multiple components. Asymmetry may involve one or several of these elements.
- Lip corner position: During smiling, both lip corners are ideally expected to be at the same horizontal level. One side elevating more than the other creates asymmetry.
- Dental midline: The midline between the upper and lower central incisors should ideally align with the facial midline (philtrum, nose tip, chin point). Deviation creates asymmetry.
- Smile arc: The relationship between the upper incisal edges and the curvature of the lower lip.
- Gum display: Equal gingival display on both sides is expected; unilateral gummy smile creates asymmetry.
- Buccal corridor: The space between the posterior teeth and cheeks should ideally appear balanced on both sides.
- Tooth height and gingival margins: Symmetry between adjacent and contralateral teeth and their gum levels.
- Occlusal plane: The relationship of the bite plane to the horizontal plane (ideally parallel to the interpupillary line). Deviation creates a “maxillary cant.”
- Soft tissue support: Symmetry of lip volume, cheek support, and surrounding soft tissues.
When Does Asymmetry Become Noticeable?
Several practical aesthetic criteria are commonly used in smile asymmetry evaluation:
- Dental midline deviation: A 1–2 mm deviation is usually acceptable and often unnoticed; deviations greater than 3 mm become clearly visible.
- Lip corner height difference: A 1–2 mm difference is usually not obvious; differences above 3–4 mm create noticeable asymmetry.
- Difference in gum display: Less than 1 mm is generally considered normal; differences greater than 2 mm become noticeable.
- Occlusal plane cant: A deviation of 1–2 degrees may be tolerated; larger deviations often create aesthetic concerns.
- These numerical criteria are not rigid rules and should always be evaluated together with the patient’s facial structure and aesthetic expectations.
Is Absolute Symmetry Realistic?
Important fact: Absolute symmetry is extremely rare in nature. Mild facial asymmetries are normal in healthy individuals; most go unnoticed and do not require treatment. Excessive pursuit of perfect symmetry may lead to unrealistic expectations in some patients, which is why realistic expectation management before aesthetic treatment is critical. The goal should not be “mathematical perfection,” but rather achieving a natural and aesthetically balanced appearance.
General Causes of Asymmetric Smile
Four major mechanisms may contribute to an asymmetric smile:
Dental Causes
Related to tooth position, number, shape, or alignment. Examples include midline deviation, missing teeth, or uneven restorations.
Gingival Causes
Differences in gum position between the two sides. Examples include unilateral gummy smile or asymmetric gum recession.
Muscle and Soft Tissue Causes
Asymmetric contraction of facial muscles. Examples include Bell’s palsy sequelae, hyperactive smile muscles, or lip asymmetry.
Skeletal Causes
Asymmetrical development of the jaw bones. Examples include hemifacial microsomia, condylar hyperplasia, or mandibular asymmetry.
In most patients, multiple mechanisms coexist. Pure single-type asymmetry exists, but mixed presentations are common. Accurate diagnosis forms the foundation of successful treatment planning.
Age and Asymmetric Smile
- Childhood: Growth-related asymmetries may often be corrected with early intervention; orthodontic monitoring is critical. Congenital conditions such as hemifacial microsomia are usually identified early.
- Adolescence and young adulthood: Pronounced asymmetry may create aesthetic concerns. Combined orthodontic and restorative approaches are frequently used.
- Adulthood: Acquired asymmetries become more common, such as tooth drifting after tooth loss, unilateral chewing habits, or trauma sequelae.
- Older age: Loss of soft tissue elasticity may make asymmetry more noticeable; fat distribution and skin sagging may differ between sides.
Gender Distribution
Asymmetric smiles occur in both male and female patients; there is no biological gender difference in prevalence. However, women more commonly seek treatment due to aesthetic concerns, likely reflecting social and cultural expectations. Aesthetic treatment demand among male patients is also increasing. Congenital and post-traumatic asymmetries are distributed equally between genders.
Is an Asymmetric Smile a “Disease”?
No. An asymmetric smile itself is not a disease; it is an aesthetic and sometimes functional finding. However, some underlying conditions may be serious and require treatment, including Bell’s palsy (acute neurological condition), condylar hyperplasia (growth disorder), tumours or cysts, hemifacial microsomia (congenital syndrome), TMJ disorders, and severe malocclusions. In such cases, asymmetry may serve as an important clinical sign, and management of the underlying condition becomes the priority. As a general rule, evaluation is recommended if the asymmetry creates aesthetic concerns or raises suspicion of a significant underlying condition.
Practical Effects
- Aesthetic impact: Imbalance of the smile line and facial proportions; in some cases causing patients to avoid smiling.
- Effect on self-confidence: Pronounced asymmetry may lead to social self-consciousness and discomfort in photographs.
- Functional impact: Patients with skeletal asymmetry may have reduced chewing efficiency and develop unilateral chewing habits, potentially leading to long-term TMJ problems.
- TMJ and muscle problems: Asymmetric occlusion may create muscle imbalance and joint disorders over time.
- Speech: In advanced asymmetry cases, pronunciation of certain sounds may be affected.
- Dental health: Uneven bite forces may overload certain teeth, increasing the risk of wear and fractures.
- Posture: In severe cases, head posture may adapt to the asymmetry, leading to imbalance in neck and shoulder muscles.
Core Principle of Treatment Planning
Correct diagnosis determines correct treatment: The treatment required for dental asymmetry (veneers, bonding, orthodontics) is completely different from the treatment required for skeletal asymmetry (orthognathic surgery). Performing the wrong type of aesthetic treatment will not produce the expected outcome and may lead to unnecessary loss of tooth structure or unsuccessful results. This is why the evaluation phase is the most important part of treatment planning; rushing into veneers or bonding is often inappropriate.
Which Conditions May Accompany Asymmetric Smile?
- Malocclusion (bite problems, crossbite, deep bite)
- TMJ disorders (joint dysfunction and pain)
- Bruxism
- Unilateral chewing habits
- Neck and shoulder muscle imbalance
- Scoliosis (back and shoulder asymmetry)
- Postural disorders
- Migraine and tension headaches
- Sequelae of childhood habits (thumb sucking, tongue thrusting, mouth breathing)
- Previous facial surgery scars
- Cleft lip and palate sequelae
- Congenital syndromes (hemifacial microsomia, Goldenhar syndrome)
Doredent Approach
At Doredent, patients presenting with asymmetric smile concerns are first evaluated to identify the underlying mechanism. Comprehensive clinical examination, smile analysis, digital photography, intraoral scanning, and when necessary advanced imaging (panoramic radiographs, cephalometric analysis, CBCT) are used for assessment. Facial symmetry measurements, dental midline analysis, gingival margin evaluation, occlusal plane analysis, and TMJ examination are performed.
For mild dental asymmetries, veneers, bonding, or limited orthodontic adjustments may be recommended. Gingival asymmetries are often treated with gum aesthetic procedures such as gingivectomy or crown lengthening. In cases of more significant dental asymmetry, orthodontic treatment (Invisalign clear aligners or braces) is usually planned first, followed by restorative treatment if needed.
Patients with skeletal asymmetry may be referred for maxillofacial surgery consultation, and orthognathic surgery may be required. In TMJ-related asymmetry cases, a TMJ splint or night guard may be recommended. Botox may be considered for Bell’s palsy sequelae or hyperactive smile muscles.
In children, early intervention may guide growth and development. Paediatric evaluations are performed by Dr. Dt. Ceyda Pınar Tanrıverdi, while orthodontic evaluations are performed by Uzm. Dt. Merve Özkan Akagündüz. Before treatment, mock-ups and digital simulations are shared with the patient, and approval is obtained before irreversible procedures are performed.
The overall principle is clear: an asymmetric smile should never be evaluated in isolation. Only when the underlying mechanism and associated conditions are considered together can the correct treatment approach be determined.
Types of Asymmetry
Four main mechanisms can underlie an asymmetrical smile: dental asymmetry, gingival asymmetry, muscle and soft tissue asymmetry, skeletal asymmetry. The treatment approach depends on correctly distinguishing these types, the intervention required for each type is distinctly different. This section covers the clinical features, distinguishing findings, and general treatment approaches for each type.Type 1: Dental Asymmetry
Asymmetry originating from the teeth: In this type, the problem lies in the teeth themselves, their position, number, or shape. The skeleton and soft tissue are usually symmetrical, the teeth are asymmetrical. The treatment approach is dental-focused: orthodontic correction, restorative treatment, or a combined approach.
Clinical Features
- The face appears symmetrical at rest, but the asymmetry of the teeth becomes prominent when smiling
- Dental midline deviation is prominent relative to the facial midline
- Gum level and lip corner position are preserved
- Discordance between adjacent teeth is noticeable
Subtypes
- Midline deviation: Dental midline is discordant with the facial midline; shift between the two jaws or relative to the facial midline
- Unilateral missing tooth: Adjacent teeth have shifted following tooth loss on one side; the other side is aligned
- Unilateral crowding: Teeth are aligned on one side, crowded on the other
- Asymmetric tooth shape or size: Opposite teeth are of different shape or size (unilateral peg lateral, asymmetric wear)
- Asymmetric restorations: Previously placed filling, crown, or veneer applications differ on both sides
- Dental shift following unilateral tooth loss: Movement of adjacent teeth toward the gap creates asymmetry
- Unilateral unerupted tooth: Impacted or late-erupting tooth on one side
- Asymmetric wear: Markedly more wear on one side (usually the result of unilateral chewing habits)
Treatment Approach
- In mild cases, correction of asymmetry with veneers or bonding
- Orthodontic treatment for significant midline deviations: clear aligners or braces
- If a tooth is missing: implant, bridge, or orthodontic space management
- For asymmetric wear cases: bruxism management (night guard) plus restorative approach
- Renewal of old asymmetric restorations
- Combined orthodontics plus restorative approach in advanced cases
Type 2: Gingival Asymmetry
Asymmetry originating from the gums: In this type, the teeth are symmetrical or mildly asymmetrical, the problem is primarily in gum position. Excessive gum display on one side, unilateral gum recession, or asymmetric development of gingival hyperplasia. Treatment requires re-establishing gum level.
Clinical Features
- Gingival margin level of opposite teeth differs
- Gummy smile on one side, normal gum display on the other
- Gum recession on one side, normal level on the other
- Visible tooth length differs on both sides (clinical crown asymmetry)
Subtypes
- Unilateral altered passive eruption: Gum has remained above the CEJ on one side, normal position on the other. Classic gingival asymmetry presentation
- Asymmetric gum recession: Gum has receded on one side (usually due to aggressive brushing, periodontitis, or trauma); normal on the other side
- Asymmetric gingival hyperplasia: Gingival hyperplasia on one side (may be drug-related, poor hygiene)
- Asymmetric lip/dental lines: Gum display is prominent on one side, lip movement appears normal
- Sequela of old periodontal surgery: Level change following surgery performed on one side
- Unilateral trauma sequela: Asymmetric healing following gum injury
Treatment Approach
- Gum contouring procedures are the basic approach
- Gingivectomy: bringing the gingival margin to a consistent level on both sides (in simple cases)
- Crown lengthening: adjusting both gum and underlying bone level (in advanced cases)
- Gum graft: re-establishing level on the side with gum recession
- Laser-assisted techniques: atraumatic, rapid healing
- Multidisciplinary approach in advanced cases (periodontics plus restorative)
Type 3: Muscle and Soft Tissue Asymmetry
Asymmetry originating from muscle movement or lip structure: In this type, teeth and gums may be symmetrical, the problem lies in asymmetric contraction of the muscles working during smiling or the asymmetric structure of the lip itself. Sequela of Bell's palsy, hyperactive smile muscle, or lip structure variations fall into this group. Treatment involves botox, filler, or soft tissue-focused approaches.
Clinical Features
- Minimal asymmetry or symmetrical appearance at facial rest
- Horizontal plane relationship of lip corners is disrupted when smiling
- One side pulls upward markedly while the other side pulls inadequately or does not rise equally
- There may be a significant difference in soft tissue volume between the two sides
Subtypes
- Bell's palsy sequela: Persistent muscle weakness following acute neurological episode; the lip corner is low on the affected side, smile is inadequate. Seen in persistent cases that have not resolved even years later
- Hyperactive unilateral smile muscle: Overactivity of the zygomaticus major or levator labii superioris muscle on one side, that side pulls upward markedly
- Short or asymmetric lip: Congenital or acquired lip size/asymmetry
- Sequela of old surgery or trauma: Persistent asymmetry following facial surgery, cleft lip operation
- Hemifacial spasm: Rare neurological condition creating involuntary muscle contractions on one side
- Synkinesis: Abnormal muscle reconnection following Bell's palsy; involuntary accompanying muscle movements
- Asymmetric fat distribution: Soft tissue volume asymmetry in advanced age
- Philtral asymmetry: Asymmetry in the upper lip philtrum region
Treatment Approach
- Hyperactive muscle: Botox application, reduces the effect of the overworking muscle, establishing balance between both sides. Lasts 3-6 months, requires reapplication
- Bell's palsy sequela: Botox to the healthy side (balancing), filler applications (volume restoration to the affected side); plastic surgery in advanced cases
- Lip asymmetry: Lip filler, lip repositioning surgery
- Hemifacial spasm: Botox effective, neurology follow-up
- Philtral asymmetry: Filler applications
- Multidisciplinary approach is often required in these types of cases (aesthetic dentist plus plastic surgery plus dermatology plus neurology)
Type 4: Skeletal Asymmetry
Structural asymmetry originating from the jaw bones: In this type, the problem lies in the jaw bones themselves, their asymmetric development, or position. It requires the most comprehensive treatment approach, orthognathic surgery (coordinated with orthodontics) is often considered. In mild cases, dental camouflage treatment can be attempted, but it does not solve the structural problem. Early diagnosis offers the opportunity for growth guidance during childhood.
Clinical Features
- Asymmetry is prominent even when the face is at rest (static asymmetry)
- Chin point (mentum) has deviated from the facial midline
- Upper jaw horizontal plane (occlusal plane) is tilted (maxillary cant)
- Facial midline, dental midline, and chin midline are discordant
- Facial volume on both sides is markedly different
- Looking at the profile, one side is forward, the other side is retracted
- Crossbite may accompany
Subtypes
- Hemifacial microsomia: Congenital syndromic condition; inadequate development of jaw, ear, and soft tissue on one side. Goldenhar syndrome is a commonly known form
- Hemifacial hypertrophy: Overgrowth of one side; rare congenital condition
- Condylar hyperplasia: Excessive growth of the TMJ condyle on one side; starts in youth, shifts the mandible to the healthy side. Intervention may be required during the active growth period
- Condylar hypoplasia: Underdevelopment of the condyle on one side; mandible shifts to the affected side
- Mandibular asymmetry: Asymmetric development of the mandibular body (trauma, childhood habits)
- Maxillary cant: Tilt of the upper jaw horizontal plane; in the smile the occlusal plane is not parallel to the interpupillary line
- Parry-Romberg syndrome: Progressive hemifacial atrophy; soft tissue and bone atrophy of one side. Rare, acquired
- Post-trauma skeletal asymmetry: If a mandibular condylar fracture occurs in childhood, growth may be disrupted; permanent asymmetry in adulthood
- Postoperative asymmetry: Following old orthognathic surgery, following tumor surgery
Treatment Approach
- Mild skeletal asymmetry: Orthodontic camouflage, reducing the appearance of asymmetry through dental movement; does not solve the structural problem but provides aesthetic improvement
- Significant skeletal asymmetry: Orthognathic surgery (coordinated with orthodontics); after growth is complete (usually over 18 years). Maxillofacial surgery follow-up
- Active condylar hyperplasia: Condylectomy (removal of the high portion of the condyle) for growth control
- Early intervention in childhood: Growth guidance appliances; skeletal-focused orthodontic approaches such as MARPE (in appropriate cases)
- Congenital syndromes: Multidisciplinary approach (maxillofacial surgery, plastic surgery, orthodontics, ENT, genetics)
- Distraction osteogenesis: In cases of advanced bone deficiency; supports bone expansion during childhood
Mixed Presentations
In clinical practice, a significant proportion of patients present with more than one mechanism together. Cases of purely single type are as common as cases where combinations are seen. Correctly identifying these mixed presentations determines the scope of the treatment plan.Dental + Gingival
Following old unilateral tooth loss, adjacent teeth have shifted, and the same side has developed gingival hyperplasia. First orthodontics or implant, then gum surgery.
Skeletal + Dental
Mandibular shift due to condylar hyperplasia plus dental midline deviation. Condylectomy plus orthognathic plus orthodontics plus restorative.
Muscle + Soft Tissue + Dental
Bell's palsy sequela plus lip asymmetry plus dental midline deviation. Botox plus filler plus restorative.
Childhood Trauma Sequela
Asymmetric growth following mandibular fracture plus crossbite plus dental shifts. Combined orthognathic plus orthodontics plus restorative.
Distinguishing Findings Between Types
- Static vs. dynamic: Static (at facial rest) asymmetry is skeletal or soft tissue in origin; dynamic (only in smile) is dental, gingival, or muscle in origin
- Chin point position: If the chin point has deviated from the facial midline, suspicion of skeletal asymmetry is high
- Lip corner height: Significant difference can be a sign of muscle-originated asymmetry
- Gingival margin level: Difference on both sides indicates gingival asymmetry
- Dental midline: Deviation is part of dental asymmetry or skeletal asymmetry
- Occlusal plane: Tilt (cant) is an important clue of skeletal asymmetry
- Frontal cephalogram: Objective evaluation of skeletal and dental asymmetry
- Age and onset: Congenital presentations (hemifacial microsomia) from birth; acquired asymmetries over years
Doredent Type Determination Approach
At Doredent, a systematic approach is followed in asymmetrical smile evaluation. A detailed clinical examination, smile analysis, digital photography (frontal, profile, 3/4, rest, smile), intraoral scanning, and if necessary, advanced imaging (panoramic, frontal cephalogram, lateral cephalogram, CBCT) are performed. The distinction between static vs. dynamic asymmetry is the fundamental question of the initial evaluation. Dental midline, gingival margin, occlusal plane, chin point position, and lip corner height measurements are taken. TMJ examination is performed, asymmetric occlusion can create TMJ problems in the long term. If a congenital condition is suspected, family history and syndromic findings are queried. A treatment plan is prepared according to the determined type or type combination: for dental asymmetry, veneers, bonding, or orthodontics; for gingival asymmetry, gum contouring; for skeletal asymmetry, referral to maxillofacial surgery. Aesthetic expectations are clarified with a mock-up, and realistic results are shared with the patient. The clinician team, Uzm. Dt. Merve Özkan Akagündüz and Dt. Buse Esen, perform type determination and treatment planning evaluation; multidisciplinary planning is applied in complex cases.Causes
The causes behind an asymmetrical smile are quite varied, ranging from congenital (present at birth) conditions to acquired (developed later) conditions, from dental causes to skeletal causes, from muscle-related conditions to neurological conditions. Most patients have more than one contributing cause. This section examines the causes of asymmetry by grouping them into etiological categories. Accurate treatment planning depends on correctly identifying these causes.1. Congenital (Present at Birth) Causes
Hemifacial Microsomia
The most common congenital facial asymmetry: Hemifacial microsomia (HFM) is the second most common congenital facial malformation after cleft lip. It is characterized by underdevelopment of the jaw, ear, soft tissue, and sometimes the facial nerve on one side. It classically presents with varying severity from mild to severe and requires a multidisciplinary treatment approach.
- Underdevelopment of the mandible and maxilla on one side
- Small or deformed ear on the affected side (microtia)
- Facial nerve involvement may occur (asymmetrical smile)
- Reduced soft tissue volume
- Classic treatment: early growth guidance, distraction osteogenesis, followed by orthognathic surgery and plastic surgery
- A practical note: Goldenhar syndrome is the spectrum of HFM that includes ear, vertebral, and eye involvement
Hemifacial Hypertrophy
- Overgrowth of one side; rare congenital condition
- Bone, muscle, soft tissue, and teeth may be affected
- Early eruption on the affected side
- May be associated with Beckwith-Wiedemann syndrome
- Treatment: orthognathic surgery and dental rehabilitation after active growth period
Other Congenital Syndromes
- Crouzon syndrome: Craniofacial dysostosis
- Apert syndrome: Syndromic craniofacial anomaly
- Pierre Robin sequence: Micrognathia, glossoptosis, cleft palate
- Treacher Collins syndrome: Mandibulofacial dysostosis
- Cleft lip and palate: Lip asymmetry, dental anomalies
- Multidisciplinary follow-up is critical for all these syndromes
Congenital Dental Anomalies
- Unilateral missing tooth (hypodontia)
- Unilateral supernumerary tooth (mesiodens)
- Asymmetrical microdontia (unilateral peg lateral)
- Unilateral eruption disturbance
- Treatment: laminate veneers, bonding, orthodontic correction
2. Childhood Acquired Causes
Childhood Trauma
An important, often overlooked cause: Mandibular condyle fractures during childhood can cause permanent asymmetric growth because they damage the growth center. Falls or impacts that are often dismissed as "minor accidents" can lead to noticeable facial asymmetry years later. For this reason, childhood facial trauma should be carefully evaluated and followed over the long term.
- Mandibular condyle fracture: damages the growth center; the affected side grows inadequately
- Facial injuries: soft tissue damage, nerve damage
- Dental trauma: developmental tooth abnormalities, eruption problems
- After jaw surgery: sequelae of tumor surgery performed in childhood
Early Childhood Habits
- Thumb sucking: Prolonged thumb sucking (over age 5) affects bone development; asymmetrical bite, crossbite may develop
- Tongue thrusting: Tongue pressure against teeth during swallowing; asymmetrical development when asymmetry exists
- Mouth breathing: Breathing through the mouth due to adenoid hypertrophy, allergic rhinitis, or other causes; narrow upper jaw, asymmetry
- Sleeping on one side: Prolonged pressure on one side; can lead to asymmetrical head shape in infancy
- Leaning on one side (supporting head with elbow or hand): Constant unilateral pressure can affect jaw development
- Early recognition and intervention for these habits is important; pediatric dentistry follow-up is critical
Adenoid and Tonsil Problems
- Enlarged adenoids or tonsils in childhood lead to mouth breathing
- Upper jaw development is affected, narrow V-shaped palate
- Asymmetrical adenoid hypertrophy causes asymmetrical effects
- ENT follow-up may be required
Childhood Eating Disorders
- Chewing on one side (usually due to toothache or decay on one side)
- Underuse of the other side, imbalance in chewing muscles
- Asymmetry in soft tissue and bone development over years
3. Adult Acquired Causes
Facial Trauma
- Traffic accidents, sports injuries, falls
- Mandible, maxilla, zygoma fractures
- Facial skin lacerations, scar tissue formation
- Poorly healed fractures cause permanent asymmetry
- Early and proper treatment (maxillofacial surgery) is critical
Dental Causes of Asymmetry
- Unilateral tooth loss: Movement of neighboring teeth into the space over years, changes in bite
- Neglected unilateral decay or root canal: The affected side is not used, chewing balance is disrupted
- Asymmetrical restorations: Inconsistency between the two sides in older laminate, crown, or bridge applications
- Relapse after unilateral orthodontic treatment: Neglect of retention, not using retainers
- Unilateral bruxism: Clenching more on one side; significant attrition on that side
Periodontal Disease
- Advanced periodontitis on one side: bone loss, tooth loss, followed by dental drifting
- Asymmetrical gum recession: clinical crown lengthens on one side, normal on the other
- Unilateral traumatic gum recession (aggressive brushing, lip or tongue piercing)
- Unilateral altered passive eruption
Unilateral Chewing Habit
- Years of chewing on one side creates an imbalance in the chewing muscles
- Masseter hypertrophy on the side being used
- Asymmetrical load on the TMJ
- Facial volume asymmetry in the long term
- Underlying dental problems (pain on one side, missing tooth) are usually investigated
4. Neurological Causes
Bell's Palsy
Common neurological cause: Bell's palsy is peripheral involvement of the seventh cranial nerve (facial nerve), causing acute onset unilateral facial muscle weakness or paralysis. The vast majority of cases resolve completely or nearly completely within a few weeks to months; however, some cases have permanent sequelae. In cases with sequelae, an asymmetrical smile is a common finding.
- Acute Bell's palsy: sudden onset unilateral facial weakness; neurological emergency treatment (corticosteroid, antiviral)
- Sequelae: permanent asymmetry months to years later; drooping corner of the mouth on the affected side, inadequate smile
- Synkinesis: abnormal nerve reconnection; involuntary associated movements such as mouth movement with eye closure
- Treatment approaches: botox to the healthy side (balancing), filler to the affected side, physical therapy, plastic surgery in advanced cases (static suspension, dynamic muscle transfer)
Hemifacial Spasm
- Involuntary contractions of facial muscles on one side
- Usually starts around the eye and spreads downward
- Vascular compression (blood vessel pressing on nerve) is the most common cause
- Treatment: botox (effective, periodic), rarely microvascular decompression surgery
- Neurology follow-up is required
Other Neurological Conditions
- Unilateral facial weakness after stroke
- Facial nerve damage after acoustic neuroma surgery
- Facial nerve damage after parotid surgery
- Traumatic facial nerve injury
- Multiple sclerosis involvement
- Ramsay Hunt syndrome (herpes zoster manifestation)
5. Skeletal and Growth Disorders (Adult)
Condylar Hyperplasia
- Overgrowth of the TMJ condyle on one side
- Usually begins in youth, may continue after the growth period
- Shifts the mandible to the unaffected side; asymmetrical jaw
- Accompanied by crossbite, dental midline deviation
- During active growth, scintigraphy is used to assess activity
- Condylectomy (removal of the upper part of the condyle) may be required in active cases
- After activity is complete, asymmetry is corrected with orthognathic surgery
Condylar Hypoplasia
- Underdevelopment of the condyle on one side
- After childhood trauma, ankylosis, rheumatoid arthritis, JIA (juvenile idiopathic arthritis)
- Mandible shifts to the affected side
- Facial asymmetry, crossbite
- Treatment: orthognathic surgery, distraction osteogenesis
Condylar Ankylosis
- Adhesion of joint surfaces; after childhood trauma or infection
- Movement is restricted + asymmetrical development together
- Treatment: surgical release, followed by orthognathic correction
Parry-Romberg Syndrome
- Progressive hemifacial atrophy; soft tissue and bone atrophy on one side
- Usually begins in childhood or adolescence, progresses over years, then stops
- Etiology unclear (autoimmune or viral hypotheses)
- Treatment: after active period, filler, fat injection, microvascular tissue transfer
6. Post-Tumor and Pathology Causes
- Jaw tumors: Ameloblastoma, odontogenic tumors; bone swelling and asymmetry
- Salivary gland tumors: Parotid, submandibular gland tumors; soft tissue asymmetry
- Vascular malformations: Hemangioma, lymphangioma; soft tissue volume increase
- Cysts: Jaw bone cysts; asymmetry depending on size
- After tumor surgery: Tissue deficiency, facial nerve damage
- Fibrous dysplasia: Bone tissue turning into fibrous tissue; asymmetrical bone swelling
- Early diagnosis is critical in all these cases; tumor/cyst must be ruled out in unexplained asymmetry
7. Postoperative and Iatrogenic Causes
- Old orthognathic surgery sequelae: Poorly planned or executed surgery
- Old plastic surgery sequelae: Asymmetrical result after facelift, filler applications
- Bone loss after tooth extraction: Prolonged unilateral gap
- Bone loss after implant failure
- After unilateral orthodontic mini-screw use
- Long-term unilateral prosthesis use
8. Age-Related Asymmetry
- Loss of soft tissue elasticity
- Fat distribution differs between the two sides
- Bone resorption due to tooth loss
- Skin sagging may not be equal on both sides
- Existing mild asymmetries become more pronounced with age
- Treatment: filler, thread lift, plastic surgery approaches
9. Systemic and Rheumatologic Conditions
- Rheumatoid arthritis: TMJ involvement can cause asymmetrical condylar changes
- Juvenile idiopathic arthritis (JIA): TMJ involvement in childhood causes mandibular growth disturbance
- Scleroderma: Skin fibrosis, soft tissue volume reduction
- Acromegaly: Excessive growth hormone production; mandibular growth (may be asymmetrical)
- Paget's disease: Abnormal bone turnover; asymmetrical bone expansion
10. Lifestyle and Behavioral Causes
- Unilateral chewing habit (significant effect over years)
- Sleeping on one side (especially during sleep)
- Leaning to one side (resting hand on cheek, holding phone with shoulder)
- Occupational exposures (glassblower, musician positions)
- Smoking (accelerates age-related skin changes)
- Excessive weight fluctuations (soft tissue balance)
- Unilateral punching habit (boxer, combat sports)
Risk Factors Summary
- Family history (congenital syndromes, developmental anomalies)
- Childhood facial trauma
- Childhood habits (thumb sucking, tongue thrusting, mouth breathing)
- Neglected unilateral dental problems
- Unilateral chewing habit
- History of Bell's palsy
- History of rheumatologic disease
- History of facial surgery
- Bruxism
- Poor oral hygiene (can be a source of unilateral tooth loss)
- Periodontal disease
- Excessively long-term orthodontic neglect
Can It Be Prevented?
Some asymmetrical smiles are preventable, while others (congenital, genetic, after acute neurological conditions) cannot be prevented. For preventable causes, the following can be done: management of childhood habits with early intervention (thumb sucking, tongue thrusting, mouth breathing (pediatric dentistry follow-up); early and proper treatment of childhood facial trauma (long-term follow-up); management of mouth breathing caused by enlarged adenoids/tonsils with ENT evaluation; early detection of dental problems through regular dental check-ups; recognition and management of unilateral chewing habits (usually resolves when underlying dental problem is addressed); appropriate prosthetic approach after tooth loss (gaps should not be left empty for long periods; implant, bridge, or orthodontic management); regular use of retention devices (retainers) after orthodontic treatment; bruxism management (night guard); preservation of periodontal health; use of sports mouthguards for patients who play sports; balanced use of both sides in sleep position. For non-preventable causes (congenital syndromes, Bell's palsy sequelae, condylar hyperplasia), early diagnosis and appropriate multidisciplinary approach are important; especially early intervention in childhood provides better long-term results.Assessment Process
The correct treatment for an asymmetrical smile starts with accurate diagnosis. The same visual finding can hide very different underlying causes: dental, gingival, muscular, or skeletal. Each type requires a distinctly different approach. That's why the assessment phase is the most important part of treatment. This section covers the clinical assessment process used at Doredent, the methods applied, and the decision-making stages.1. Detailed Medical History
Characteristics of the Chief Complaint
- When did you first notice the asymmetry?
- Has it been present since childhood, or did it develop later?
- Has it changed over time, stayed the same, or gotten worse?
- Is it only visible when you smile, or is it present at rest too?
- Which side is more noticeable? (Which side is affected?)
- What are your aesthetic expectations?
- What bothers you most?
- Have you had any previous dental or cosmetic treatment?
Associated Findings
- Jaw pain, TMJ complaints
- Unilateral chewing habit
- Morning jaw stiffness, headaches (bruxism)
- Reduced chewing efficiency
- Speech changes
- Difficulty swallowing
- Limited facial movement or involuntary movements
- Neck, shoulder, or posture pain
- Vision or hearing issues (syndromic conditions)
Trauma History
- Childhood facial trauma (often-forgotten critical history)
- Adult facial trauma (accidents, sports injuries)
- Past facial surgery
- Previous tumor or cyst surgery
- Dental trauma
- Past events suggesting condylar fracture
Childhood Habits
- Thumb sucking: for how long?
- Tongue thrust
- Mouth breathing (past or current)
- History of adenoid or tonsil problems
- Sleeping on one side
- Leaning on one side (resting hand on cheek, etc.)
Medical and Family History
- History of Bell's palsy (timing of acute episode, treatment response)
- Other neurological conditions (stroke, MS, hemifacial spasm)
- Rheumatological diseases (rheumatoid arthritis, JIA, scleroderma)
- Systemic diseases (acromegaly, Paget's disease)
- Congenital syndromes
- Family history (facial asymmetry, syndromic conditions)
- Current medications
- Previous orthodontic treatment, retainer compliance
- Previous tooth extractions and reasons
2. Clinical Examination
Static Facial Analysis (At Rest)
Static vs dynamic distinction: Symmetry is assessed when your face is at rest. If asymmetry is present even when you're not smiling, it indicates a structural issue involving the skeleton or soft tissue. This distinction is the first major decision in treatment planning.
- Facial midline: The vertical midline is assessed using glabella (midpoint of forehead), nasal tip, philtrum (upper lip midline), and chin point (mentum) as references
- Interpupillary line: The horizontal plane between the eyes; this line is compared to the mandibular and maxillary horizontal planes
- Rule of fifths: The face is divided into five equal vertical segments; proportional assessment
- Rule of thirds: Upper, middle, and lower facial heights should be in one-third proportions
- Chin point position: Is there deviation from the facial midline? (Important clue for skeletal asymmetry)
- Mandibular border: Is it symmetric on both sides, or asymmetric?
- Facial volume: Are cheek, jaw, and forehead volumes equal on both sides?
- Skin: Color, texture, scar tissue, presence of old injuries
Dynamic Smile Analysis
- Commissure height: Horizontal plane relationship of the corners of your mouth during a smile
- Smile symmetry: Does your upper lip elevate equally on both sides?
- Gum display: Is there a gummy smile? Is it unilateral or symmetric?
- Tooth display: Is the visible amount of upper teeth equal on both sides?
- Buccal corridor: The space between your back teeth and cheek; is it equal on both sides?
- Assessment during speech: Observation not just during a posed smile, but during natural conversation
- Different smile types: Social smile (weak), Duchenne smile (genuine); does the asymmetry change?
Intraoral Examination
- Dental midline: Relationship of the upper and lower central incisors' midline to the facial midline and philtrum
- Occlusion assessment: Upper-lower jaw relationship, presence of crossbite, deep bite, open bite
- Lateral movements: Jaw movement range to right and left; symmetry between the two directions
- Protrusion: Whether the chin point moves straight or curves during forward jaw movement
- Gum level: Gingival margin position of corresponding teeth
- Tooth height and width: Correspondence of opposing teeth
- Missing teeth or supernumerary teeth
- Existing restorations: Veneers, bonding, crowns, bridges; are they symmetric on both sides?
- Wear facets: Signs of bruxism, presence of asymmetric wear
- Periodontal assessment: Pocket depths, recession, bleeding
TMJ Examination
- Joint palpation (tenderness on both sides)
- Joint sounds (clicking, crepitation)
- Deviation during opening (jaw shifting to one side)
- Measurement of opening range
- Lateral movement range
- Palpation of chewing muscles (masseter, temporal, medial pterygoid)
- Masseter hypertrophy (equal on both sides, or more prominent on one side?)
Cranial Nerve Examination
- Facial nerve (7th cranial nerve): eyebrow raise, eye closure, smile, lip pursing; each movement assessed separately
- Trigeminal nerve (5th cranial nerve): sensation in three facial regions
- Detailed neurological assessment if Bell's palsy sequelae suspected
- Neurology consultation if needed
3. Imaging Methods
Panoramic X-ray
- General dental and jaw assessment
- Asymmetric bone development
- Condyle structure and size (suspected condylar hyperplasia/hypoplasia)
- Detection of unerupted, impacted, missing teeth
- Presence of tumors or cysts
- First-line imaging
Cephalometric X-ray (Lateral)
- Assessment of facial skeletal structure from side profile
- Maxilla-mandible relationship
- Vertical facial dimension
- Basis for orthodontic analysis
Frontal Cephalogram
Gold standard for asymmetry assessment: The frontal cephalogram (postero-anterior cephalometric radiograph) allows frontal assessment of facial skeletal structure. Facial midline, mandibular deviation, maxillary cant, condylar asymmetry, and mandibular ramus and body asymmetry can be objectively measured. It's a critical imaging modality when skeletal asymmetry is suspected.
CBCT (Cone Beam Computed Tomography)
- 3D skeletal assessment: gold standard
- Detailed analysis of condylar size and structure
- Mandibular and maxillary asymmetry measurement
- Tumor or cyst assessment
- Surgical planning: orthognathic surgery, condylectomy
- Dental midline and occlusal relationship
- Virtual surgical planning capability
CT and MRI
- CT: for advanced surgical planning, tumor spread assessment
- MRI: TMJ soft tissue assessment (disc position), tumor soft tissue detail, facial nerve involvement
- Comprehensive evaluation in congenital syndromes like hemifacial microsomia
Scintigraphy (Bone Scan)
- When active condylar hyperplasia is suspected
- Objective assessment of condylar activity
- Distinguishes active vs inactive condition
- Important for surgical timing decision
4. Digital Assessment and Documentation
Digital Photography
- Facial photos: frontal, profile, three-quarter view
- Photos at rest and during smile
- Extraoral and intraoral photos
- Standardized positioning, consistent lighting
- For before-and-after comparison
- Objective data for aesthetic analysis
Digital Scanning (Intraoral Scan)
- 3D digital model of your teeth
- For precise measurements
- Basis for mock-up planning
- Orthodontic and restorative planning
- Communication tool with patients
3D Facial Scanning (Stereophotogrammetry)
- Creation of a 3D digital model of your face using advanced techniques
- Quantitative measurement of asymmetry
- Objective comparison of treatment outcomes
- For surgical planning
Smile Design (Digital Smile Design)
- Preview of planned treatment results on your facial photo
- Visualization of asymmetry correction plan
- Aligning your expectations with clinical possibilities
- Clarity before irreversible procedures
Mock-Up Application
- Temporary demonstration of planned treatment results in your mouth
- You live with the planned teeth and smile for several days
- The most reliable way to manage expectations
- Especially important in asymmetry correction
5. Cases Requiring Multidisciplinary Assessment
In some cases, one specialty isn't enough. A multidisciplinary team approach is needed.- Skeletal asymmetry: Maxillofacial surgery + orthodontics + aesthetic dentistry
- Congenital syndromes: Genetics + maxillofacial surgery + plastic surgery + ENT + orthodontics
- Bell's palsy sequelae: Neurology + plastic surgery + aesthetic dentistry + dermatology (Botox/fillers)
- Condylar hyperplasia: Maxillofacial surgery + orthodontics + nuclear medicine (scintigraphy)
- Rheumatological conditions: Rheumatology + dentistry
- Post-tumor/cyst asymmetry: Oncology + maxillofacial surgery + plastic surgery
- Pediatric cases: Pediatric dentistry + orthodontics + ENT + growth monitoring
6. Treatment Planning Stages
After assessment is complete, the treatment plan is developed in stages:- Urgency assessment: Active conditions (condylar hyperplasia in active phase, suspected tumor) are addressed first
- Management of causative factors: If bruxism, childhood habits, or eating disorders are present, the underlying cause is addressed
- Establishing periodontal health: Gum health is optimized before restorative or surgical procedures
- Surgical phase (if needed): Orthognathic surgery, condylectomy, gingivectomy; healing periods
- Orthodontic correction: May take months; before and after orthognathic surgery
- Mock-up application and approval: Preview of results before restorative work
- Restorative phase: Veneer, bonding, crown applications
- Soft tissue procedures: Botox, fillers (in applicable cases)
- Maintenance phase: Night guard, hygiene education, retainer
- Follow-up: Regular checkups, necessary adjustments
7. Critical Questions in Treatment Planning
- Which type is dominant? (Dental, gingival, muscular, skeletal, or mixed?)
- Static or dynamic asymmetry?
- Is there an active condition (growing, progressing)?
- What is the patient's age, and is the growth period complete?
- Congenital or acquired?
- Are the patient's expectations realistic?
- Is a multidisciplinary approach needed?
- Is an irreversible procedure necessary?
- How long will the results last? (Stability)
- What is the cost-benefit analysis?
- Is the patient's hygiene and compliance capacity adequate?
8. Doredent Assessment Approach
At Doredent, asymmetrical smile assessment is a systematic and multifaceted process. The initial exam includes a detailed history, clinical examination, digital photography (static and dynamic), smile analysis, and necessary imaging. The static vs dynamic asymmetry distinction is the critical first question. Facial midline, dental midline, gingival margin, occlusal plane, and TMJ are evaluated. History of Bell's palsy, childhood trauma, and childhood habits are explored in detail. Imaging is planned: panoramic as baseline, frontal cephalogram (specialized asymmetry assessment), and CBCT for 3D analysis if needed. Based on the identified type or combination of types, treatment options are shared with you: for dental asymmetry, laminate veneers, bonding, orthodontics; for gingival asymmetry, gum contouring and gingivectomy; for skeletal asymmetry, referral to maxillofacial surgery; for muscular asymmetry, Botox assessment. In pediatric cases, early intervention is planned; Dr. Dt. Ceyda Pınar Tanrıverdi in pediatric dentistry and Uzm. Dt. Merve Özkan Akagündüz in orthodontics provide care. Mock-up and digital simulation are used to preview the planned outcome with you; realistic expectation management is a core part of treatment. The clinical team performs multidisciplinary planning in complex cases; the team is supported by Dt. Buse Esen. The guiding principle is this: managing causative factors, accurately identifying the type, and establishing realistic expectations are essential steps before aesthetic treatment.Frequently Asked Questions
When I smile in the mirror, one side lifts higher than the other. What causes this, and can it be corrected?
Asymmetrical smile is often caused by muscle, gum, or tooth-related factors. Today, most of these asymmetries can be successfully corrected with cosmetic dentistry and facial aesthetic treatments.
One of the most common causes is unilateral hyperactive smile muscle. The face appears symmetrical at rest, but during smiling, the muscle on one side contracts more strongly and lifts the lip higher on that side.
For this type of dynamic asymmetry, the most common treatment is low-dose botox. By reducing the activity of the hyperactive muscle, a more balanced appearance can be achieved between both sides. The effect typically lasts 3 to 6 months.
In some patients, the issue is not that one side lifts too high, but that the other side does not move enough. Mild muscle weakness, especially after Bell's palsy, can cause this appearance.
In these cases, balancing botox, filler support, or physical therapy may be planned. More advanced cases may require plastic surgery approaches.
Another common cause is uneven gum levels (gingival asymmetry). Excessive gum display on one side can make the smile appear asymmetrical.
In such cases, a more symmetrical appearance can be achieved with gum contouring or gingivectomy procedures.
In some patients, the problem stems from tooth position or size. Wear, crowding, or differences in tooth length can increase smile asymmetry. In these cases, veneers, bonding, or orthodontic treatments may be planned.
In rarer cases, the issue is skeletal asymmetry due to differences in jaw bone position. If the face appears noticeably asymmetrical even at rest, orthognathic surgery evaluation may be needed.
The first step for successful treatment is a detailed examination and smile analysis. At Doredent, digital photography is taken at rest and during smiling to evaluate static and dynamic asymmetries and create a personalized treatment plan.
Most mild cases can be significantly improved with botox or gum contouring procedures. The goal is not perfect mathematical symmetry, but rather a natural, balanced smile that harmonizes with your face.
I've had Bell's palsy in the past, and one side of my face still doesn't smile properly. What can be done?
Your situation is considered a sequela of Bell's palsy and is typically addressed by a multidisciplinary approach involving aesthetic dentistry, dermatology, and sometimes plastic surgery. While most Bell's palsy patients recover completely, some develop persistent muscle weakness or involuntary muscle movements (synkinesis).
The most common issue is reduced movement of the corner of the lip on the affected side. When you smile, one side works more noticeably while the other remains subdued. In some patients, the healthy side begins to overcompensate over time, making the asymmetry more pronounced.
Another condition is called synkinesis. In this scenario, muscles reconnect abnormally, and involuntary movements (such as eyelid twitching) may occur when you smile.
Treatment plans vary depending on the type of sequela. One of the most common methods is low-dose botox injections. By balancing the hyperactive muscles on the healthy side, a more symmetrical appearance can be achieved. In patients with synkinesis, targeted botox can be applied to the involuntarily contracting muscles. The effect typically lasts 3 to 6 months.
In some patients, hyaluronic acid fillers can provide volume support on the affected side. A more balanced appearance can be achieved, especially in cases of volume loss around the cheek and lip area.
Physical therapy and facial exercises can also play a supportive role. Mirror therapy, muscle exercises, and biofeedback techniques may benefit some patients.
In more advanced cases, plastic surgery options may be considered. Surgical procedures such as static suspension or muscle transfers can be evaluated, especially in cases of pronounced asymmetry.
At Doredent, we start with a detailed smile and facial analysis in such cases. We assess whether the asymmetry is due to muscle issues, dental factors, or neurological sequelae. When necessary, we may recommend multidisciplinary planning with dermatology and plastic surgery.
An important point is that even if years have passed since your Bell's palsy, treatment options are still available. Significant improvement can be achieved with current aesthetic and medical approaches. The goal is not perfect symmetry, but a more natural, balanced, and harmonious facial appearance.
My jaw is shifted to one side and my teeth don't close evenly. What should be done?
What you're experiencing is a common example of skeletal asymmetry and requires detailed evaluation. Different underlying causes are possible, and treatment planning varies accordingly. This condition is usually not just about the teeth, it's related to jaw bone development and positioning.
One of the most common causes is condylar hyperplasia, excessive growth of the jaw joint condyle on one side. In this case, the lower jaw may shift to the opposite side and facial asymmetry can develop. In some patients, growth remains active and further evaluation may be needed.
Another possibility is condylar hypoplasia, underdevelopment of the jaw joint on one side. Childhood trauma, joint problems, or certain rheumatic diseases can cause this.
In some patients, old condyle fractures from childhood that went unnoticed can affect the growth center. This can lead to asymmetric jaw development.
In rarer cases, congenital developmental differences (hemifacial microsomia) or unilateral crossbites may also contribute to the condition.
In these types of cases, the first step is detailed evaluation. Along with clinical examination, panoramic X-ray, frontal cephalometric analysis, and if needed, three-dimensional imaging with CBCT can be performed. If active growth is suspected, scintigraphy may be requested.
Treatment planning varies based on the underlying cause. In mild cases, orthodontic camouflage can reduce the appearance, but it doesn't fully resolve the structural problem.
In more pronounced skeletal asymmetries, orthodontics and orthognathic surgery can be planned together. This process typically consists of several stages and total treatment time can reach 2 to 3 years.
In some patients, TMJ splint or night guard applications can help reduce the load on the joint, but they don't correct skeletal asymmetry.
For this reason, aesthetic procedures alone like bonding or veneers are often insufficient. Without proper evaluation of the structural problem, such treatments may be inadequate and can create long-term issues.
At Doredent, detailed orthodontic evaluation is performed in these types of cases, necessary imaging is planned, and maxillofacial surgery referral is provided when needed. Uzm. Dt. Merve Özkan Akagündüz coordinates the orthodontic planning process.
Treatment of skeletal asymmetries can be lengthy and staged, but with proper planning, significant improvements can be achieved in both facial symmetry and chewing function.
My dental midline doesn't align with my facial midline — what can be done?
This is known as dental midline deviation and is a common finding in smile aesthetics. When the midline of your upper and lower front teeth doesn't align with your facial midline, your smile may appear asymmetrical.
Minor deviations are usually not noticeable. Shifts of 1-2 mm often don't require treatment, while deviations of 3 mm or more can become more apparent.
Midline deviation may be purely dental in origin. It can result from neighboring teeth drifting into a space after tooth loss, crowding, or individual tooth movements. In these cases, your facial structure is typically symmetrical, the problem is mainly with tooth positioning.
In other cases, the deviation is skeletal. A positional difference in your upper or lower jaw can cause the dental midline to shift away from the facial midline. In these situations, facial asymmetry may be visible even at rest.
Your treatment plan depends on the degree and cause of the deviation. Minor deviations may not need treatment, or limited cosmetic adjustments may be sufficient.
For moderate deviations, orthodontic treatment is usually the best approach. Invisalign clear aligners or braces can realign your teeth and create a more balanced midline.
More significant deviations may require skeletal evaluation. In these cases, your jaw structure is assessed with frontal cephalometric analysis or CBCT. Skeletal cases may require a combined plan of orthodontics and orthognathic surgery.
When tooth loss causes shifting, managing the space is important. In some cases, a dental implant and orthodontic realignment can be planned together.
If you've had orthodontic treatment but stopped wearing your retainer, your teeth may shift back. This may require orthodontic correction again.
At Doredent, we evaluate these cases with a clinical exam, digital photography, intraoral scanning, and necessary radiological imaging. We analyze your facial midline, dental midline, and jaw relationship together.
Uzm. Dt. Merve Özkan Akagündüz provides orthodontic planning, and Dt. Buse Esen handles the restorative phase.
Dental midline deviation is often manageable. However, rushing into veneers or bonding may not always be the right solution. For a lasting, balanced result, the cause of the deviation should be identified first.
I used to chew on one side as a child, and now I have noticeable facial asymmetry. Can it be reversed?
What you're experiencing is facial asymmetry that developed due to long-term one-sided chewing. Over the years, imbalances in the chewing muscles, jaw joint, and teeth can affect facial appearance. While a complete return to the original state isn't always possible, significant improvement can be achieved.
With one-sided chewing, the masseter and chewing muscles on the active side work harder and may increase in volume. On the less-used side, muscle weakness can develop, creating a volume difference in the face.
Over time, this can also create uneven stress on the jaw joint (TMJ). Some patients may experience joint clicking, pain, jaw fatigue, or bite problems.
This habit often stems from an underlying dental issue. Decay, missing teeth, sensitivity, or poorly fitted restorations can cause someone to unconsciously start chewing on one side, which then becomes a habit.
The first step is to identify and correct the underlying dental problem. If teeth are missing, implants or appropriate restorations can be planned. Cavities, bite problems, or old ill-fitting crowns are treated.
When necessary, braces or clear aligner treatment can rebalance the bite.
In cases with significant tooth wear, aesthetic and functional balance can be restored with veneers, bonding, or porcelain restorations.
For patients with noticeable muscle volume asymmetry, masseter botox can reduce the overactive muscle. In some cases, filler support may be planned for the weaker-appearing side.
If nighttime clenching or bruxism is present, a night guard may be recommended. For patients with TMJ complaints, a TMJ splint can support treatment.
Changing the habit is as important as muscle balance. Physical therapy, chewing exercises, and conscious bilateral chewing play a key role in long-term treatment success.
At Doredent, we perform detailed bite, muscle, and joint analysis for such cases. When needed, restorative dentistry, orthodontics, dermatology, and physical therapy can be coordinated.
The goal isn't perfect symmetry, but a more balanced, natural, and functional facial structure. Regular follow-up and patient compliance are essential parts of treatment.
One corner of my mouth is always lower, I look asymmetric even when I'm not smiling — what can be done?
What you're experiencing is called static lip asymmetry. This means there's a noticeable height difference between the corners of your mouth even when your face is at rest. It differs from dynamic asymmetries that only appear when smiling and may have more structural causes.
One of the most common causes is muscle weakness following old Bell's palsy or facial nerve damage. The affected side can't maintain proper muscle tone, so the corner of the mouth appears lower.
In some patients, the problem isn't the weak side but overactivity of the muscles on the opposite side. The healthy side pulls upward more, making the asymmetry more noticeable.
Soft tissue volume differences can also cause lip asymmetry. Age-related volume loss, old trauma, or surgical procedures can reduce support on one side.
More rarely, congenital lip shape differences, old injuries, or jawbone asymmetries may also contribute. If your chin is also off-center, a skeletal evaluation may be needed.
The treatment plan depends on the underlying cause. For mild to moderate cases, one of the most common approaches is dermal filler. Hyaluronic acid fillers can add support and volume to the corner of the mouth, creating a more balanced appearance.
For patients where muscle imbalance is the main issue, low-dose botox may be an option. Reducing muscle activity on the overactive side can help restore balance between the two sides.
In some patients, facial exercises and physical therapy can also be supportive. In more advanced cases, plastic surgery approaches may be considered.
For significant skeletal asymmetries, orthodontics and orthognathic surgery may be evaluated together. In these cases, treatments like lip filler alone won't fully resolve the structural problem.
At Doredent, we perform a detailed facial analysis for these cases, assessing the lips, muscles, jaw, and facial midline together. When necessary, we can refer you to dermatology or maxillofacial surgery.
In most cases, the goal isn't perfect mathematical symmetry but rather a more natural, balanced appearance that harmonizes with your face. With modern aesthetic approaches, lip asymmetries can be effectively managed.
Can Botox correct smile asymmetry, and is it a permanent solution?
Yes, Botox is a highly effective treatment for certain types of asymmetrical smile. It is especially preferred when muscles work more on one side, helping to balance facial movements. However, it is not permanent; its effect is temporary and requires repeat applications at regular intervals.
Botox (botulinum toxin) temporarily reduces the movement strength of the muscle where it is applied. The effect typically begins within a few days, reaches full results in 2-4 weeks, and lasts an average of 3-6 months.
One of the most common uses is for unilateral hyperactive smile muscles. If one side lifts more when you smile, reducing muscle activity in that area can achieve a more balanced appearance.
Botox is also frequently used in patients with Bell's palsy sequelae. Especially if the healthy side is overworking, balancing applications can significantly reduce asymmetry.
In patients with unilateral gum display (asymmetric gummy smile), low-dose Botox applied to specific muscles can reduce gum visibility.
For pronounced chewing muscle enlargement on one side of the face, masseter Botox applications can help balance facial volume asymmetry.
However, Botox is not effective for every type of asymmetry. If the problem originates from the jawbone, relates to tooth position, or involves significant volume loss, different treatments may be needed. In these cases, orthodontics, restorative procedures, filler applications, or orthognathic surgery are considered.
Correct dosage and precise injection points are crucial in Botox applications. Overdose or incorrect application can cause temporary smile imbalances. Therefore, planning by an experienced practitioner is necessary.
After the first application, full results may take a few weeks to settle. Early evaluation should not be rushed.
The advantage of Botox is that it is reversible and low-risk. Unsatisfactory results are not permanent. The disadvantage is that the effect diminishes over time and requires regular repeat treatments.
At Doredent, we first evaluate the underlying cause in asymmetrical smile cases. We analyze whether the problem is muscle-based, dental, or skeletal. When necessary, orthodontic or restorative planning is performed; for Botox applications, a dermatology referral may be recommended.
The goal is not to create a frozen or artificial appearance, but to achieve a more natural, balanced smile that harmonizes with your face.
My child's smile is asymmetrical—will it improve as they grow, or do we need to intervene now?
Facial and smile asymmetry in children is evaluated differently than in adults because growth is still ongoing. Some asymmetries may improve over time, while others can become more pronounced with growth. That's why early assessment is important.
Mild temporary asymmetries can occur during the transition from baby teeth to permanent teeth. Often, balance is achieved as tooth eruption completes.
However, prolonged thumb sucking, tongue thrusting, or mouth breathing can affect jaw development and lead to problems like crossbite.
Sleeping on one side or constantly leaning on one cheek can also influence facial development during growth.
Childhood trauma is also important. Old injuries to the jaw joint area, in particular, can cause facial asymmetry years later.
In rarer cases, congenital developmental differences (hemifacial microsomia, cleft lip sequelae, etc.) may occur and require multidisciplinary follow-up.
Early evaluation in children provides a major advantage. Because growth is ongoing, jaw development can be guided and some problems can be controlled without surgery.
When necessary, early orthodontic treatments, crossbite corrections, or orthopedic approaches like MARPE can be planned for appropriate cases.
In children with mouth breathing, snoring, or suspected enlarged adenoids, an ENT evaluation is also important.
The American Association of Orthodontists recommends the first orthodontic evaluation around age 7. If there is significant asymmetry or bite problems, earlier assessment may be needed.
At Doredent, pediatric dentistry evaluations are performed. Dr. Dt. Ceyda Pınar Tanrıverdi provides care in pediatric dentistry, while Uzm. Dt. Merve Özkan Akagündüz leads the orthodontic assessment process.
In children with facial asymmetry, a "wait and see" approach may not always be the right choice. Many problems identified early can be managed more easily with conservative methods.
Content Information
This page was prepared by the Dore Medical Editorial Board and medically reviewed by Dr. Merve Özkan Akagündüz.
