Managing Orthodontic Assessments

Managing Orthodontic Assessments

Structures orthodontic evaluation with Angle classification, cephalometric analysis, treatment option documentation, and progress monitoring per AAO diagnostic standards.

Why This Skill Exists

Orthodontic assessment requires integration of clinical examination, radiographic analysis, and model analysis into a unified diagnosis and treatment plan. Misclassification of malocclusion type, failure to identify skeletal discrepancy versus dentoalveolar compensation, or overlooking periodontal contraindications leads to treatment plans that produce unstable results or iatrogenic harm (root resorption, dehiscence, relapse). This skill enforces systematic diagnostic records collection, standardized classification, and evidence-based treatment option documentation per AAO guidelines.

Checkpoint A — Records Collection Verification

Required Diagnostic Records (AAO Standard)

• Panoramic radiograph (dentition status, root morphology, pathology, third molar assessment)
• Lateral cephalometric radiograph (skeletal and dental relationships)
• Intraoral photographs (frontal, right lateral, left lateral, upper occlusal, lower occlusal)
• Extraoral photographs (frontal at rest, frontal smiling, profile at rest)
• Dental impressions or digital intraoral scans for study models
• Periodontal screening (probing depths, BOP at minimum) — active periodontal disease must be controlled before orthodontic treatment
• Complete medical and dental history

Intake Questions

1. What is the patient's chief complaint (esthetic concern, functional problem, or both)?
2. What is the patient's age and growth status (prepubertal, pubertal, post-growth)?
3. Has the patient had prior orthodontic treatment, and if so, what was done and what was the outcome?
4. Is there a family history of malocclusion or jaw surgery?
5. Does the patient have any habits (thumb sucking, tongue thrust, mouth breathing, bruxism)?
6. Is there active periodontal disease, and has it been treated?
7. Are there any TMD symptoms (pain, clicking, locking, limited opening)?

Step 1 — Clinical Examination and Classification

Perform systematic occlusal analysis and classify the malocclusion.

• Angle Classification:
  • Class I: Mesiobuccal cusp of upper first molar occludes in the buccal groove of lower first molar; malocclusion involves crowding, spacing, or individual tooth malposition
  • Class II Division 1: Lower molar distally positioned relative to upper; proclined upper incisors with increased overjet
  • Class II Division 2: Lower molar distally positioned; retroclined upper central incisors with deep overbite
  • Class III: Lower molar mesially positioned relative to upper; may present with negative overjet (anterior crossbite)
• Canine relationship: Class I (upper canine tip in embrasure between lower canine and first premolar), Class II (upper canine mesial), Class III (upper canine distal)
• Overjet: Horizontal distance between labial surface of lower incisor and incisal edge of upper incisor; measure in mm; normal 2–4 mm
• Overbite: Vertical overlap of upper incisors over lower incisors; measure as mm or percentage of lower incisor coverage; normal 2–4 mm (20–30%)
• Crossbites: Posterior (buccal or lingual), anterior; unilateral vs. bilateral; document whether functional shift is present
• Crowding/spacing: Measure arch length discrepancy in mm per arch using Carey's analysis or digital measurement
• Midline assessment: Dental and facial midline relationship; document deviation in mm and direction

Step 2 — Cephalometric Analysis

Analyze lateral cephalometric radiograph for skeletal and dental relationships.

• Skeletal anteroposterior: SNA (normal 82° ± 2°), SNB (normal 80° ± 2°), ANB (normal 2° ± 2°); Wits appraisal as supplementary measure
• Skeletal vertical: FMA or mandibular plane angle (normal 25° ± 5°); anterior and posterior face height ratio; hyperdivergent (high angle) vs. hypodivergent (low angle) pattern
• Dental measurements: U1 to SN (normal 104° ± 2°), IMPA / L1 to mandibular plane (normal 90° ± 5°), interincisal angle (normal 130° ± 5°)
• Soft tissue analysis: Ricketts E-line (upper lip 4 mm behind, lower lip 2 mm behind in adults), nasolabial angle (normal 90–110°)
• Growth assessment: Cervical vertebral maturation (CVM) staging for timing of functional appliance therapy; hand-wrist radiograph if CVM is equivocal
• Skeletal vs. dental classification: Determine whether the malocclusion is skeletal (jaw size/position discrepancy), dental (tooth position within normal jaws), or combination — this drives the treatment approach fundamentally

Step 3 — Model Analysis and Space Assessment

Evaluate dental models (physical or digital) for space and arch form.

• Bolton analysis: Anterior ratio (normal 77.2% ± 1.65%) and overall ratio (normal 91.3% ± 1.91%) to detect tooth-size discrepancy between arches
• Arch length discrepancy: Measure available arch perimeter minus sum of mesiodistal widths of all teeth; positive = spacing, negative = crowding
• Curve of Spee: Measure depth from deepest point to plane across incisal edges and distal cusp tips; > 2 mm may need leveling (requires arch perimeter)
• Mixed dentition analysis: Use Tanaka-Johnston or Moyers prediction tables to estimate unerupted canine and premolar sizes
• Arch form: Classify as tapered, ovoid, or square; document asymmetries
• Space management: For pediatric/mixed dentition — assess leeway space, E-space, and need for space maintenance or serial extraction

Step 4 — Treatment Option Documentation

Present evidence-based treatment alternatives based on diagnosis.

• Growth modification (skeletal cases in growing patients): Functional appliances (Twin Block, Herbst, MARA) for Class II skeletal; facemask/protraction headgear for Class III skeletal; palatal expander (RPE/MARPE) for transverse deficiency
• Fixed appliances: Conventional brackets (MBT, Roth prescription), self-ligating systems; document bracket prescription, wire sequence, and estimated treatment time
• Clear aligner therapy: Indications (mild-moderate crowding, spacing, mild Class II), limitations (severe skeletal discrepancy, significant vertical problems, poor compliance), system specification (Invisalign, SureSmile, 3M Clarity)
• Extraction vs. non-extraction: Document arch length discrepancy, profile analysis, and rationale for extraction pattern (first premolars, second premolars, or asymmetric extraction)
• Orthognathic surgery: Indicated for skeletal discrepancies beyond dentoalveolar compensation in non-growing patients; Le Fort I, BSSO, or bimaxillary; document surgical treatment objective (STO) and orthodontic-surgical coordination plan
• Retention plan: Must be included in initial treatment plan — Hawley retainer, clear essix retainer, bonded lingual retainer; document planned retention protocol and duration

Step 5 — Risk Assessment and Informed Consent

Document treatment risks specific to orthodontic therapy.

• Root resorption: External apical root resorption occurs in nearly all orthodontic patients; risk factors include prior trauma, dilacerated roots, and heavy force application; monitor with periapical radiographs at 6–9 months
• White spot lesions / decalcification: Risk with fixed appliances and poor oral hygiene; document oral hygiene assessment and fluoride protocol
• Periodontal risks: Bone dehiscence from proclination beyond alveolar housing, gingival recession from expansion beyond bone limits; periodontally compromised patients require lighter forces and longer intervals
• TMD risk: Orthodontic treatment neither causes nor cures TMD per AAO position; document pre-existing TMD signs and symptoms as baseline
• Relapse: Expected degree of post-treatment settling; document retention compliance requirements
• Treatment duration estimate: Provide realistic range (typically 18–30 months for comprehensive treatment); document factors that may extend treatment (compliance, growth, complexity)

Checkpoint B — Assessment Completeness Review

• Complete diagnostic records collected (radiographs, photographs, models/scans)
• Angle Classification assigned with canine relationship
• Overjet, overbite, crossbites, and midline documented in mm
• Cephalometric analysis completed with skeletal and dental measurements
• Skeletal vs. dental etiology determined
• Model analysis completed with arch length discrepancy and Bolton analysis
• Growth status assessed (CVM stage or hand-wrist maturation)
• Treatment alternatives documented with rationale for recommended approach
• Extraction vs. non-extraction decision documented with justification
• Risks and informed consent documented including root resorption, WSL, TMD, and relapse
• Retention plan included in treatment plan

Quality Audit

Guidelines

• Use Angle Classification as the primary occlusal classification system; supplement with skeletal analysis from cephalometrics — never treat based on Angle class alone without skeletal assessment
• Cephalometric analysis must identify skeletal vs. dental etiology before treatment planning; skeletal problems in growing patients may benefit from growth modification, while the same problems in non-growing adults may require surgery
• Active periodontal disease must be treated and stable before initiating orthodontic tooth movement; confirm periodontal clearance in writing
• Bolton analysis is critical when planning interdisciplinary cases (ortho-prostho) to ensure proper interdigitation after restorative work
• Document all habit patterns (tongue thrust, lip incompetence, mouth breathing) as these affect treatment stability and may require myofunctional therapy
• Growth modification appliances are only effective in growing patients — confirm growth status with CVM or hand-wrist radiograph before prescribing functional appliances
• Clear aligners have documented limitations for complex movements (bodily movement of teeth, vertical control, significant rotation of round teeth); document why aligners were chosen or why they were not appropriate
• Monitor for external root resorption with periapical radiographs at 6–9 months of treatment; if > 2 mm of resorption detected, consider treatment pause and lighter forces
• All orthodontic assessment reports must include a retention plan — failure to plan retention is planning for relapse