Classification and Recording of Malocclusion
- Angles classification: Class II Division 1, Class II Division 2, Class III
- Based on the relationship of maxillary and mandibular first molars
- Describes 3 classes of malocclusion: Class I, Class II, Class III
- Massler and Frankels index records the number of displaced/rotated teeth
- Introduced in 1951 by Massler & Frankel
- Records prevalence of malocclusion
- Uses individual teeth as unit of occlusion
- Each maloccluded tooth is given a value of 1
- Score of 0 indicates perfect occlusion, score of more than 10 indicates need for orthodontic treatment
- Malalignment Index introduced in 1959 by Lawrence Vankirk and Elliott Pennell
- Uses a small plastic gauge-like tool for assessment
- Measures tooth rotation and displacement
- Mouth is divided into 6 segments for scoring measurement
- Score of 0 represents ideal alignment, score of 1 represents minor malalignment, score of 2 represents major malalignment

Assessment of Treatment Need and Priority
- Grade Index Scale for Assessment of Treatment Need (GISATIN)
- Created by Salonen L in 1966
- Grades the type and severity of malocclusion
- Treatment Priority Index (TPI)
- Created by R.M. Grainger in 1967
- Assesses the severity of common types of malocclusion
- Handicapping Malocclusion Assessment Record (HMAR)
- Created by Salzmann JA in 1968
- Establishes treatment needs for handicapping malocclusion
- Littles Irregularity Index (LII)
- Measures linear displacement of tooth contact points
- Model cast can be ranked on a scale of 0-10
- WHO/FDI - basic method for recording of malocclusion
- Developed by the Federation Dentaire Internationale (FDI)
- Uses prevalence of malocclusion to estimate treatment needs
- Subjective judgment of orthodontic treatment need: non necessary, doubtful, necessary
- Index of Orthodontic Treatment Need (IOTN)
- Developed and tested in 1989 by Brook and Shaw in England
- Determines treatment priority and eligibility for orthodontic treatment on the NHS in the UK
- Comprises dental health component (DHC) and aesthetic component (AC)
- Memorandum of Orthodontic Screen and Indication for Orthodontic Treatment
- Implemented in 1990 by Danish national board of health
- Describes health risks related to malocclusion and identifies treatment need
- Ideal Tooth Relationship Index (ITRI)
- Established in 1992 by Haeger
- Utilizes intra-arch and inter-arch relationships to generate index scores
- Need for Orthodontic Treatment Index (NOTI)
- First described and implemented in 1992 by Espeland LV et al
- Used by the Norwegian health insurance system for allocation of treatment subsidies
- Risk of Malocclusion Assessment (ROMA)
- Published in 1998 by Russo et al for use in exchange for the IOTN scale

Assessment of Orthodontic Treatment Outcome
- Assessment of treatment outcome is important in orthodontics
- The American Board of Orthodontics (ABO) cases have been used to evaluate treatment outcome
- Three-dimensional dental arch and palatal form changes can be assessed after extraction and nonextraction treatment
- The desire for orthodontic retreatment has been studied in different populations
- Public community orthodontics in Italy has been described as an experience

Comparison of Orthodontic Treatment Need Indexes
- Different orthodontic treatment need indexes have been compared
- The PAR Index and other indexes have been assessed for their validity and reliability
- The IOTN has been used in the UK to determine treatment need
- The Danish National Board of Health has provided guidelines for orthodontic screening and treatment indications
- The assessment of treatment outcome in ABO cases has been evaluated

Prevalence of Malocclusion
- Malocclusion is a common dental condition
- A study found that the prevalence of malocclusion in children aged 14 to 18 years was high
- Another study reported a prevalence of malocclusion in a specific population group
- The prevalence of malocclusion can be assessed and graded using different methods
- Variability exists in recording and grading the need for orthodontic treatment based on malocclusion