OUTLINE. INTRODUCTION/DEFINITIONS: CROWDING SERIAL EXTRATIONHISTORY OF SERIAL EXTRACTIONRATIONALE INDICATIONSCONTRAINDICATIONSDIAGNOSISPROCEDUREADVANTAGESDISADVANTAGES. INTRODUCTION. Interceptive orthodontics has evolved clinically and objectively over t
1. SERIAL EXTRACTION
BY ADEYEMI PAUL BOT.
2. OUTLINE INTRODUCTION/
HISTORY OF SERIAL EXTRACTION
3. INTRODUCTION Interceptive orthodontics has evolved clinically and objectively over the year.
The word interceptive orthodontics reveals a much better understanding of clinical possibility and limitation unlike the earlier word ‘preventive’ orthodontics used.
One of the procedure been carried out under interceptive orthodontics is serial extraction
4. Crowding Crowding of the tooth is caused by a faulty relationship between jaw size,and tooth size.
5. CROWDING The size of the jaw determines the relationship of the apices to one another, the arch perimeter limits the relationship of the crowns and the tooth size comes between the two.
6. serial extraction Serial extraction is a form of interceptive orthodontic treatment which aims to relieve crowding at an early stage so that the permanent teeth can erupt into good alignment, thus reducing or avoiding the need for later appliance therapy
7. Chronologically, crowding may become manifested at 7 years of age on eruption of the incisors, at 10 to 12 years on eruption of the canines, premolars or during the late teens in the form of late labial segment imbrications
8. It is define as a timely planned extraction of primary and ultimately secondary teeth to relief crowding. It is initiated when there is crowding especially in incisor crowding. It was developed in Europe as a way of dealing with severe space problems.
9. History of serial extraction. Bunon in 1743 must be credited with the original concept but Kjellgren and Hotz certainly popularized the ideal.
Kjellgren “serial extraction” and Hotz’s “guidance of eruption” were terms that emerged simultaneously in Europe during the late 1940s
Nance during the 1940s popularized this technique in the USA and termed it ‘planned & progressive extraction.
10. RATIONALE Serial extraction is based on two principles:
Arch length-tooth material discrepancy: whenever there is an excess of tooth material as compared to the arch length, it is advisable to reduce the tooth material in order to achieve stable results. This principle is utilized in serial extraction procedure where tooth material is reduced by selective extraction of the teeth so that the rest of the teeth can be guided to normal occlusion.
11. Physiologic tooth movement:
Human dentition shows a physiologic tendency to move towards an extraction space. Thus by selective removal of some teeth the rest of the teeth which are in the eruption are guided by the natural forces into the extraction spaces
12. INDICATIONS The patient should be between 8 to 9 years of age and the incisor crowded
The fundamental arch relationship should be normal (Angle class I). showing harmony between skeletal and muscular system.
13. ‘’Arch length deficiency as compared to tooth material is the most important indication for serial extraction’’. This is indicated by:
Absence of physiological spacing
Unilateral or bilateral premature loss of deciduous canines with midline shift.
Malpositioned or impacted lateral incisor that erupt palatally out of the arch
14. 4. Markedly irregular or crowded upper or lower anteriors
5. Localized gingival recession in the lower anterior region is a xstic feature of arch length deficiency
6. Ectopic eruption of teeth
7. Mesial migration of buccal segment
8. Abnormal eruption pattern & sequence
9. Lower anterior flaring
10. Ankylosis of one or more teeth
15. There should be normal or reduce overbite and all the teeth should be present on radiograph and in good position to erupt.
There should be a large arch perimeter deficiency of 10mm or more.
16. The first premolar should be more close to eruption than the canines
It is rather rare to find a patient who fulfils all these criteria to the letter. How much latitude should be allowed, calls for clinical judgment and a consultant option.
17. CONTRAINDICATION Serial extraction are contraindicated in a number of conditions:
Class II & III malocclusion with skeletal abnormalities
Anodontia / oligodontial
Open bite & deep bite
Class I malocclusion with minimal space deficiency
Unerupted malformed teeth e.g. dilaceration
Extensive caries or heavily filled first permanent molars
Mild disproportion between arch length and tooth material that can be treated by proximal striping.
18. DIAGNOSTIC PROCEDURE The 1st step is to assess that a malocclusion exist in a clinical examination and the need for investigation and collection of diagnostic records . Comprehensive assessment of the dental , skeletal and soft tissue is required.
The investigation required are as follows;
19. STUDY MODEL
Assess the dental anatomy of the teeth
Assess the intercuspation of teeth
Assess the arch form and curve of occlusion
Evaluate the occlusion
Undertake model analysis i.e. arch perimeter analysis , Carrey's analysis , mixed dentition analysis using tarnaka and Johnston e.t.c.
Also used between and after treatment.
Intra oral x-rays e.g. periapicals , occlusal views.
Extra oral x-rays e.g. cephalometric , panoramic views e.t.c.
The above provide the following information;
Detection of congenitally missing teeth , supernumerary e.t.c.
Detection of any bony pathosis.
To assess the stages of root development and the possible eruption pattern.
To determine the dental age of the patient.
21. 5. To assess the different relationship between craniofacial structures using cephalometric analysis.
6. To assess facial patterns
7. To assess soft tissue matrix
8. To assess changes in mid and post tx relationship cephalometrically to monitor treatment progress.
22. summary Diagnostic exercise before treatment involves
Assessment of the dental, skeletal & soft tissues.
A tooth material-arch length discrepancy must ideally exist.
According to most authors, an arch length deficiency of not <5-7mm should exist.
Study model analysis should be carried out to determine the arch length discrepancies
Mixed dentition analysis must be done this help to determine the space required for the erupting buccal teeth
Skeletal tissue assessment should involve comprehensive cephalometric examination to study the underlying skeletal relation.
23. PROCEDURES Different procedures has been described by different authors such as;
Tweed’s method 1966;8years [DC4].
Dewel’s ,, 1978; 81/2[CD4]
Nance’s ,, 1940; D4C
24. Dewel’s method – CD4 Proposed a 3 serial extraction procedure
Removal of deciduous canines to create space for the alignment of the incisors (btw 8-9 years)
A year after, the removal of deciduous first molars to aid quick eruption of the first premolars
This is followed by the extraction of first premolars to permit the permanent canines to erupt in their place.
25. In some cases a modified Dewel’s technique is followed wherein the first premolars are enucleated at the time of extraction of the first deciduous molars
This is necessary in the mandibular arch where the canines often erupt before the first premolars
26. Tweed’s method -DC4 This method involves the extraction of the 1st deciduous molars around 8-years of age
This is ffd by the extraction of 1st premolars & the deciduous canines simultaneously.
Nance method is similar to –D4C
27. Advantages of serial extraction Treatment is more physiologic as it involves guidance of teeth into normal positions making use of physiological forces.
Psychological trauma associated with malocclusion can be avoided by treatment of the malocclusion at an early age
Serial extraction can relieve incisor crowding and produce reasonably good alignment of teeth without any orthodontic appliance therapy
Serial extraction makes later comprehensive orthodontic treatment easier and quicker
28. It eliminates or reduces the duration of multibanded fixed treatment.
Better oral hygiene is possible thereby reducing the risk of caries
29. Health of investing tissues is preserved
More stable results are achieved as the tooth material and arch length are in harmony.
30. It does not involve mechanical treatment
Cost is minimal
It is often within the range of general practitioners
Malocclusion can be treated at early age
31. Disadvantages of serial extraction Treatment time is prolonged as this is carried out in stages spread over 2-3 years .
It requires the patient to visit the dentist often, thus patient co-operation is needed.
Extraction of the buccal teeth can result in deepening of the bite
32. As extraction spaces created are closed gradually, the patient has tendency of developing tongue thrust.
Child is subject to series of extraction at a tender age
These may well be a child’s first experience of dental treatment and might cause subsequent psychological problems with their attitude to dentistry, especially as the experience is to be repeated as the programe of extraction proceeds.
33. Improper sequence of extraction may leads to delay eruption of secondary teeth
Lower secondary canine may erupt before secondary first molar
34. There could be possible loss of space after the extraction i.e. if there is a delay.
If the procedures are not carried out properly, there is a risk of arch length reducing by mesial migration of the buccal segment. Thus a poorly executed serial extraction programe can be worse than none at all
35. Ditching or space can exist between the canine and second premolar
The axial inclination of teeth at the termination of the serial extraction may require correction. This necessitates short term fixed appliance therapy
36. conclusion A good preventive techniques will result in a reducemalocclusion
38. 7 THANK’S