The aim of balancing and compensating extractions is to preserve occlusal relationships and arch symmetry within the developing dentition.  
Balancing extraction: Removal of a tooth from the opposite side of the same dental arch (e.g. UR6 and UL6).
Compensating extractions: removal of a tooth from the same side of the opposing dental arch (e.g. UR6 and LR6).

When is a balancing or compensating extraction required?Potential causes of prolonged retention of primary teethSpace maintainersReferences
Primary incisors (A/B)Balancing/compensating extraction NOT required
Primary canines (C )Early loss of a primary canine (except in spaced dentition) is likely to have most effect on centreline.

In crowded dentitions a balancing extraction is required.
First primary molar (D)Early loss of a primary first molar may require a balancing extraction in a crowded arch.

Compensation of first primary molars are NOT required.
Second primary molar (E)Does not affect centreline so a balancing extraction is not required.

A secondary molar extraction may lead to the tilting of the adjacent first permanent molar. Thus, following a primary second molar extraction, space maintenance should be considered.

In the event of an unbalanced extraction of a primary canine/ primary first molar one of three situations will occur: 

  • NO centreline shift- do not balance 
  • Centreline shift with complete space closure- delay balancing until a full orthodontic assessment  
  • Centre line shift with spacing remaining mesial to the extraction site. Monitor to determine whether tooth movement is continuing if so seek orthodontic advice

In the following cases a referral to a paediatrician or orthodontist is required, an over retained tooth can defect the eruption path of permanent successors: 

  • Absence of permanent successor 
  • Infra-occlusion 
  • Ankylosis  
  • Crowding  
  • Supernumeraries  
  • Odontomes 

The aim of space maintainers is to preserve space for the permanent dentition, they are often used to prevent malocclusion of the permanent teeth or to replace absent teeth in the permanent dentition.  

Space maintenance is usually required: 

  • Following the loss of a primary first molar where crowding is severe, i.e. more than 3.5mm (half a unit) per quadrant.  
  • Loss of primary second molar, except in spaced arches 

Types of space maintainer: 

  •  A natural tooth 
  • Partial denture 
  • Upper removable appliances 
  • Band and Loop 
  • Nance appliances 
  • Stainless steel crown and loop 
  • Trans palatal arch 
  • Lingual arch

Extraction of Primary Teeth–Balance and Compensation. The Clinical Effectiveness Committee of The Faculty of Dental Surgery of The Royal College of Surgeons of England. September 2001, updated November 2006.

Cobourne MT, Williams A, Harrison M. A Guideline for the Extraction of First Permanent Molars in Children. The Royal College of Surgeons of England, Faculty of Dental Surgery 2014.(Update of the 2004 guideline by M.Cobourne, A.Williams & R.McMullan, previously updated in 2009).

See also Orthognathic Surgery