photographs should be obtained before any active treatment is started. Full-face and
profile photographs are a record of facial form, including lip morphology. Intraoral
photographs are a further record of the malocclusion, give some indication of the
standard of oral hygiene, and are valuable where enamel defects are present before
treatment.
14.2.2 Need and demand for orthodontic treatment
The Index of Orthodontic Treatment Need (IOTN) is based upon the severity of the
malocclusion, and has been developed to try to establish a consensus within the
profession as to which malocclusions will gain a worthwhile benefit from orthodontic
treatment. The complexity and difficulty of treatment do not necessarily depend upon
the severity of the malocclusion, and mild malocclusions often need extensive and
sophisticated treatment if any improvement is to be made at all. Other indices have
been developed to assess the complexity and success of treatment. The IOTN has two
components:
- The Dental Health Component categorizes malocclusion into five grades (893HTable
14.2) according to severity, based upon current evidence for the detrimental effects of
various occlusal features. A malocclusion is graded according to its worst feature.
Patients in grades 1 and 2 have little or no indication for treatment on dental health
grounds, while those in grades 4 and 5 are considered to have a definite need for
treatment. The borderline cases in grade 3 require a degree of judgement when
deciding upon their need for treatment, and the appearance of the dentition can be
taken into account using the Aesthetic Component of the IOTN. - The Aesthetic Component of the IOTN uses a scale of 10 photographs showing
different levels of dental attractiveness (894HFig. 14.1). The appearance of the dentition is
rated using the photographs as a guideline. Grades 1-4 indicate little or no need, for
treatment on aesthetic grounds, grades 5-7 are borderline, and patients in grades 8-10
would clearly benefit from orthodontic treatment. It is, however, difficult to be truly
objective when making judgements of this kind about an individual's appearance, and
the Aesthetic Component has not achieved universal use because of its subjective
nature.
Demand for orthodontic treatment is affected by many factors. Patients vary
enormously in how they perceive their own dental appearance, some apparently being
unaware of obvious malocclusions while others express dissatisfaction about very
minor irregularities. Demand for treatment thus depends upon the severity of the
malocclusion as perceived by patients and parents rather than by dentists. It is also
affected by patients' attitudes to wearing orthodontic appliances, which are influenced
by the appearance of the appliances and how acceptable they think appliance
treatment is among their peers. Demand for orthodontic treatment tends to increase as
appliances become more common and accepted among a population, but it is also
greatly affected by the availability of treatment (geographic accessibility, waiting
lists, etc.).