Class III skeletal deformity with anterior crossbite
23-year-old male
§Chief complaint
Lower jaw sticks out and I cannot bite my front teeth together
§Medical & dental history
- 01Fit and well; growth complete confirmed on hand-wrist radiograph
- 02Full dentition, good oral hygiene, pre-surgical orthodontics for 14 months
§Clinical examination
- 01Concave profile, prominent chin, negative overjet of 6 mm
- 02Maxillary hypoplasia with paranasal flattening; lower facial third increased
- 03Class III molar and canine relationship bilaterally, anterior and posterior crossbite
- 04TMJ asymptomatic, mouth opening 48 mm
§ figuresFigures (2)
Fig. 1Pre and post Orthodontics were done by Dr, Vipin Challiyil and Orthognathic surgery was done by Dr. Aju Ommen .
“Orthognathic surgery” · Challiyan · CC BY-SA 4.0 · Wikimedia Commons
Fig. 2Osteotomies of the maxilla and mandible. 1. Lefort I 2. Bilateral sagittal split 3. Genioplasty
“Orthognatic surgery” · Henry Grey · Public domain · Wikimedia Commons
Verified open-access images only, reproduced for education under their stated licences · no AI-generated or illustrative artwork · Orthognathic Surgery figures pending faculty review.
§Differential diagnosis
§Final diagnosis
Skeletal Class III deformity: maxillary hypoplasia with mandibular prognathism, requiring bimaxillary surgery
Cephalometric analysis distinguishes true skeletal Class III from a dentoalveolar (pseudo) Class III, which can be corrected by orthodontics alone. A negative ANB with reduced SNA confirms the maxilla is the major contributor here, so a bimaxillary approach gives the best facial result.
§Investigations
- 01Lateral cephalogram — SNA 76, SNB 85, ANB -9 degrees
- 02CBCT with 3D virtual surgical planning and printed splints
- 03Study models and digital occlusal set-up
- 04Photographic and functional records; bone scan to confirm no active condylar growth
§Treatment plan
- 01Pre-surgical orthodontic decompensation (completed)
- 02Bimaxillary surgery: Le Fort I maxillary advancement 5 mm with mandibular setback 4 mm via BSSO
- 03Genioplasty as required for chin projection
- 04Post-surgical orthodontics and long-term retention
§Surgical procedure
- 01Le Fort I osteotomy, downfracture and advancement, fixation with four L-shaped plates
- 02Bilateral sagittal split osteotomy setback with bicortical screws, IAN identified and protected
- 03Intermediate and final splints from virtual planning; occlusion checked before closure
§Follow-up & outcome
- 01Guiding elastics for 4 weeks; soft diet 6 weeks
- 02Stable Class I occlusion at 6 months
- 03Lower lip paraesthesia largely resolved by 9 months; patient satisfaction high
§Clinical pearls / learning points
- 01Decompensate the arches fully before surgery or the skeletal movement will be limited.
- 02Inferior alveolar nerve disturbance after BSSO is common and must be consented for explicitly.
- 03Virtual surgical planning improves accuracy but does not replace intraoperative occlusal checking.
§ evidenceReferences & Evidence
Current Classification
WHO Classification of Tumours Online — Head and Neck
IARC / WHO · 2022
Continuously updated online edition of the WHO head and neck tumour classification.
Evidence summary
Highest level of evidence linked to this page: WHO / Official Classification.
- L1 · Classification — 1
- L3 · Systematic review — 1
- L6 · Textbook — 4
1 linked source was published from 2024 onwards. Where guidance is limited or contested, rely on the higher-level sources above rather than this summary. Educational use only — not a substitute for clinical judgement.
Content last reviewed
September 2026
Evidence last reviewed
September 2026
Next scheduled review
September 2027
Review status
EVIDENCE REVIEWED
Search latest PubMed evidence
Last literature search: 7 September 2026
Current Classification
IARC / WHO. IARC · 2022
Continuously updated online edition of the WHO head and neck tumour classification.
Systematic Reviews & Meta-Analyses
Wang M, Zhang B, Li L et al.. European journal of orthodontics · 2022 · 44(1):1-10
Systematic review of vertical skeletal stability across orthognathic treatment protocols.
Histopathology References
Barnes L. CRC Press · 2008
Detailed histopathological reference for head and neck diagnostic criteria.
Textbook References
Neville BW, Damm DD, Allen CM et al.. Elsevier · 2024
Standard reference textbook of oral and maxillofacial pathology used throughout this atlas.
Rajendran R, Sivapathasundharam B. Elsevier · 2020
Undergraduate and postgraduate oral pathology textbook widely used in BDS and FCPS curricula.
Hupp JR, Ellis E, Tucker MR. Elsevier · 2019
Core surgical textbook covering exodontia, infection, trauma and preprosthetic surgery.
Additional sources cited on this page
- Proffit WR, White RP, Sarver DM. Contemporary Treatment of Dentofacial Deformity.
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