Arch Expansion Case Study: Non-Surgical Rapid Palatal Expansion for Facial Asymmetry in a Teen Female

Despite being close to skeletal maturity, timely diagnosis and a CBCT-based assessment of the midpalatal suture allowed us to perform non-surgical rapid palatal expansion (RPE). The patient’s esthetic concerns were addressed through a two-phase orthodontic treatment plan that included skeletal expansion followed by fixed appliance therapy. This approach not only corrected the functional shift and smile asymmetry but also avoided surgery and extractions — all within a 12-month timeframe.

“My chin looks off to the left when I close my mouth.”
“My smile looks uneven — one side is too dark.”
“There’s no space for my upper teeth, and I find brushing hard.”

• Severe crowding in upper anterior teeth

• Canine crossbite and posterior crossbite on the left side

• Narrow V-shaped upper jaw with buccal corridor asymmetry

• Maxillary first molars positioned palatally, contributing to transverse maxillary deficiency and aiding in arch width assessment

• Facial asymmetry due to functional mandibular shift

• Chin deviated to the left during closure

• Smile arc collapsed on left side, exaggerated by arch width deficiency

This patient presented with a classic case of maxillary transverse deficiency, resulting in:

• Functional occlusal shift toward the left
• Maxillary transverse deficiency requiring suture assessment
• Buccal corridor asymmetry and smile imbalance

The patient also exhibited a transverse skeletal discrepancy contributing to the clinical presentation.

The constricted maxillary arch caused the mandible to shift during closure, mimicking skeletal asymmetry. Diagnosis confirmed that the deviation was functional, not skeletal — opening the door for non-surgical correction through rapid palatal expansion.

The planned intervention aimed to achieve both skeletal and dental changes to correct the deficiency.

The clinical examination and diagnostic records distinguished a functional bite shift from a fixed skeletal asymmetry before expansion was planned.

🔎 Key Challenges:

• Patient approaching 16 years, requiring individual assessment of skeletal maturity
• Midpalatal suture maturity and periodontal limits needed assessment
• The patient’s aesthetic concerns and treatment preferences were discussed
• Crossbite, arch width and smile arc required coordinated planning

📊 Suture Maturity Check:

• CBCT was used in this case to assess midpalatal suture maturation.
• The recorded Angelieri Stage C finding supported consideration of tooth-borne expansion alongside the clinical assessment; no single stage guarantees a response.

Phase 1: Rapid Palatal Expansion (RPE)

• Appliance: Banded Hyrax palatal expander with molar tubes
• Prescribed activation for this patient: 1 turn morning and evening for 14 days
• A 1 mm midline gap developed during expansion; clinical reviews monitored the response
• The appliance was retained passively for 3 months. Activation schedules must follow the treating orthodontist’s instructions.

Phase 2: Fixed Appliances (MBT 0.022)

• Brackets bonded directly over bands without removing RPE

• Wire sequence:
  0.014 Cu NiTi → 0.018 Cu NiTi → 0.019×0.025 Cu NiTi → 0.019×0.025 SS

• RPE removed after 7 months

• Smile arc refined, canine root torque applied, midline aligned

Pre-treatment frontal view

• Constricted upper arch

• lateral incisor in cross bite

• lower arch shift towards left side

• wide buccal corridor space on left side

Post-treatment frontal view

• Midline aligned

• All cross bites corrected

• Lower arch well aligned with upper arch

• Right and left buccal corridors spaces are balanced

Pre - Treatment Right occlusal view

• Class - I Canine Relationship

• Class - I Molar Relationship

Post - Treatment Right occlusal view

• Class I Canine Relationship

• Class I Molar Relationship

• Ideal occlusal contacts

Pre - Treatment left occlusal view

• Lateral Incisor in crossbite

• Posterior crossbite at left side occlusion

Post - Treatment left occlusal view

• Cross bites corrected

• Class I Canine Relationship

• Class I Molar Relationship

• Ideal occlusal contacts

Pre‑treatment maxillary arch

• Narrow V-shaped upper arch

• Crowding in the anteriors

• Constricted at posterior region

Post‑treatment maxillary arch

• Expanded upper arch

• Corrected upper midline

• Achieved ideal U-Shaped arch form

Pre‑treatment mandibular arch

• Mild Crowding

Post‑treatment mandibular arch

• Corrected crowding

• Well aligned lower teeth

• Achieved ideal arch form

• Precisely Placed lower fixed retainer

• Chin realigned without jaw surgery

• Posterior crossbite and dental crowding corrected; posterior expansion was achieved to correct the bite

• Balanced buccal corridors and smile arc achieved

• Functional mandibular shift resolved

• Skeletal and dental expansion attained through non-surgical RPE

• This case demonstrates the effectiveness of orthodontic treatment in resolving complex asymmetry

“This case underscores how CBCT-based diagnosis and timely rapid maxillary expansion can resolve apparent asymmetry in teens approaching skeletal maturity. By expanding the maxillary arch with a palatal expander, we restored occlusion, symmetry, and patient confidence — all without extractions or surgery.”

• Upper retainer worn full-time for 6 months, then nights only

• Patient educated on hygiene, retainer use, and follow-up schedule

• This case involved a narrow upper arch, posterior crossbite and a functional shift. The records supported a trial of tooth-borne rapid palatal expansion. Age alone does not establish suture maturity or suitability; other adolescents and adults may require a different expansion approach.

• The reported expansion response allowed this patient’s treatment to proceed without surgically assisted expansion. The degree of skeletal and dental change varies, and review is needed to monitor the supporting tissues and bite.

• Upper arch width and symmetry were coordinated with the lower arch during treatment. Retention and follow-up remain necessary; an end-of-treatment photograph does not establish long-term stability.

• The expander applied controlled forces to widen the upper arch. The response was reviewed during treatment, with non-surgical expansion selected for this individual diagnosis.

• Palatal expansion may use rapid or slow protocols and tooth-borne, bone-supported or combined appliances. Age, suture maturity, the amount of constriction and periodontal limits guide selection. Selected mature patients may need MARPE or surgically assisted expansion; conventional expansion is not suitable for every adult.

• Reviews monitored tooth tipping, supporting tissues, arch width and bite changes. These checks guide adjustments and help identify unwanted effects during expansion.

• This case documents bite and arch correction, not a measured treatment outcome for sleep apnoea. Snoring, persistent mouth breathing or suspected sleep apnoea needs appropriate medical assessment. Expansion may be considered in selected multidisciplinary care, but airway improvement cannot be promised from these photographs.

Dr. Sree, Specialist Orthodontist, Dubai

Appointments with Dr. Sree in Dubai. Phone / WhatsApp: +971 58 596 3637.