Methods to provide space in orthodontic treatment can be memorized using SPEEDRAL acronym which stands for:
· Stripping of inter-proximal enamel,
· Proclination of incisors,
· Distalisation of molars,
· Rotation of teeth,
· Angulation of teeth, and
· Leeway space
· IPR also known as reproximation, enamoplasty, keystoning, enamel approximation and slenderizing.
· IPR was re-popularised by Sheridan in 1985.
On which teeth we can preform IPR?
· Mainly lower incisors.
· Sometimes, macro-premolars.
· Rarely, upper incisors unless they are wide or with black triangle.
Indications of IPR
· Providing space to treat crowding and overjet problems. Sheridan (1985) reported that IPR can provide up to 8.9mm per quadrant which is quite optimistic!
· Improvement of form and size of teeth.
· Treatment of black triangle (Sarver 2011).
· Management of TSD discrepancies.
· Enhance stability (Peck and Peck 1972).
· Interceptive treatment by serial reproximation (Boese 1980).
Limitations of IPR
· Overlapped teeth.
· Angulated teeth.
· Barrell shaped teeth.
· PDL compromised teeth.
· Artificial crowns.
· Hypersensitive teeth.
How do we do IPR?
A. Interproximal separation (for posterior teeth),
B. Enamel reduction either one or more of the following options:
· Manual technique using strips or saws.
· Motor-based either air-rotor stripping or reciprocating saw.
· Acid-Enhanced Technique in which the acid enhances other methods of enamel striping to finish with smooth surfaces (Rossouw and Tortorella, 2003).
C. Space measurements and more striping if required,
D. Then, finishing and smoothing followed by the application of desensitising agents.
Problems of IPR
Not very common (El-Mangoury et al. 1991, Zachrisson et al. 2007) but could include:
· Periodontal damages,
· Teeth sensitivity,
· Pulp and damage (not a high risk, Banga 2021), and
· More than 4mm could induce TSD.
Uncertainty and update
It is not clear whether the rate and location of IPR varied according to the type of malocclusion. To answer this uncertainty, AJODO journal, in their March 2021 issue, published a paper titled (Association between incisor positions and amount of interdental stripping in patients undergoing orthodontic treatment). The paper was undertaken by Dr Ozturk and Dr Yagci from Turkey.
This study included 60 patients who were divided into 3 groups: Class I, Class II, and Class III groups (n = 20 per group). All patient had non-extraction orthodontic treatment.
Conclusion of the recent paper
· Patients with Class II malocclusion needed more IPR for posterior teeth than anterior teeth
· Patients with Class III malocclusion need IPR mostly in the mandibular anterior teeth.
Link to the paper:
What do you think?