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Orthodontic diagnosis is complex and multifactorial and an initial space analysis informing a decision on whether to extract teeth is consistently highlighted as the most significant diagnostic factor, with other clinical factors being secondary. Although the majority of clinicians are taught a method of space analysis, few subsequently place their confidence in any formal method and furthermore, may not consider the space implications of the curve of Spee. A survey of orthodontists revealed a surprising variability in the assessment of crowding, as well as a tendency to make a different diagnostic decision on the same case sometime later. This two-part series explores the current status of space analysis and suggests how we may be able to limit the potential for making poor extraction decisions. Part 1 explores the various factors that need to be considered in an orthodontic space analysis and in particular the space implications of the curve of Spee. Part 2 examines the various methods and tools available to the clinician in assessing orthodontic crowding. We also look at ways in which potentially poor extraction decisions may be mitigated in clinical practice.
CPD/Clinical Relevance: To help understand the clinical significance of space analysis as the key diagnostic factor informing a decision whether to extract teeth or not.
Article
I (CW) attended a lecture in 1991 by Tom Graber, who had been an expert witness for over 200 State Board litigation cases against orthodontists. In one particular case, the presiding judge was, according to Graber, astounded by the defence that assessment of crowding was made by a seemingly unscientific ‘experienced eyeballing’. The prosecuting lawyers, some ‘specializing’ in orthodontics, quoted several papers that highlighted the unreliability of ‘eyeballing’ and the inconsistencies amongst orthodontists when reaching extraction decisions. Tom Graber concluded his lecture with the observation that ‘… if you are an orthodontist in California and you extract teeth, you will get sued…and if you are an orthodontist in California and you don't extract teeth, you will get sued.’
Orthodontic diagnosis is complex and multifactorial, but a poor treatment outcome may carry an assumption of an incorrect diagnosis; the extraction decision being consistently highlighted as the most significant contributory factor, the choice of appliances being secondary.1 Deferring the extraction decision in borderline situations can be a way of ‘hedging your bets’ but, despite initial warnings to the patient of the possibility of mid-treatment extractions, late extraction decisions are often not well received.
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