Serial extraction is the planned extraction of certain deciduous teeth and specific permanent teeth in an orderly sequence and predetermined pattern to guide the erupting permanent teeth into a more favorable position.
History
In 1929, Kjellgren of Sweden used the term "serial extraction" for the first time. In the 1940s the technique was popularised in the United States by Hayes Nance as “planned and progressive extraction”. Nance is known as the Father of serial extraction in the United States. In 1970 Hotz in Switzerland called it active "supervision of teeth by extraction."
Procedure
There is no fixed technique to be followed while carrying out serial extractions. Careful diagnosis and continuous re-evaluation during the course of treatment is mandatory to achieve required results.
However based on the usual eruption sequence of teeth, deciduous canines are extracted at the age of 8–9 years to create space for proper alignment of incisors, followed by extraction of deciduous first molars a year later so that the eruption of first premolars is accelerated and lastly extraction of the erupting first premolars to give space for the alignment of permanent canines. In some cases a modified technique is followed in which the first premolars are enucleated at the time of extraction of the deciduous first molar. This modification is frequently necessary in the mandibular arch where the canines often erupt before the first premolars.
Selection of suitable extraction procedure
Extracting the primary canines only – it produces rapid self-improvement in incisor crowding and alignment intercepting the development of lingual crossbite of the lateral incisors.
Extracting the first primary molars only – this approach produces the earlier eruption of first premolars but reduces the rapidity and amount of incisor alignment. This is the result of retention of primary canines.
Extracting both primary canines and first molars – this is a compromise between rapid improvement in incisor alignment and the desired early eruption of first premolars. In some cases this sequence results in simultaneous eruption of canines and first premolar, which may cause an increased distal translation of the permanent canines and possible impaction of first premolars.
Enucleation of first premolar buds – it is advocated when first premolar eruption is behind that of canines and second premolars. This allows maximal distal translation of the erupting canines.it is rarely indicated in the maxillary arch.
Indications
In cases of class 1 malocclusion that show harmony between skeletal and muscular system Cases which present with arch length deficiency – indicated by the presence of one or more of the following: Absence of physiologic spacing Unilateral or bilateral premature loss of deciduous canines with midline shift Malpositioned or impacted lateral incisors that erupt palatally out of the arch Markedly irregular or crowded maxillary and mandibular anteriors Localized gingival recession in the mandibular anterior region Ectopic eruption of teeth Mesial migration of buccal segment Abnormal eruption pattern and sequence Mandibular anterior flaring Ankylosis of one or more teeth Cases with insufficient growth to overcome the tooth material – basal bone discrepancy. Patients with straight profile and pleasing appearance.
Contraindications
Class 2 and class 3 malocclusion with skeletal abnormalities. Patients with adequate spacing in dentition Cases of anodontia/oligodontia Patients with open bite and deep bite In cases of midline diastema Class 1 malocclusion with minimal space deficiency Unerupted malformed teeth e.g. dilacerations Extensive caries or heavily filled first permanent molars Mild disproportion between arch length and tooth material that can be treated by proximal stripping
Advantages
Treatment is more physiologic
Psychological trauma can be avoided by treatment at an early age
Reduces the duration of fixed orthodontic treatment
Better oral hygiene is possible, so reduced risk of caries
Health of investing tissues (periodontium and alveolar process) is preserved, therefore reduced alveolar bone loss Less retention period is indicated More stable results are achieved Less potential iatrogenic damage Normal neuromuscular balance is achieved and maintained