Interceptive Orthodontics Question And Answers

Interceptive Orthodontics

Question 1. Write short note on space regainers.
Answer. It is a device used to regain the space lost by tipping movement of a tooth into extracted space.

It should be used at an early age before the eruption of second molar.

Types of Space Regainer

• Removable Space Regainer
  • Removable appliance with finger spring
  • Removable lingual arch
  • Split saddle regainer
  • Knee spring.
  • Spacer regaining with expansion screws

Read And Learn More: Orthodontics Question And Answers

• Fixed Space Regainer
  • Gerber space regainers
  • Lingual arch
  • Lip bumper
  • Open coil space regainer
  • Headgears.
  • Fixed intra-arch appliances.

Commonly used space regainers are Gerber space regainer, Jackscrew, Cantilever spring.

Indications

• It is done when deciduous maxillary or mandibular second molar lost prematurely.
• In cases with ectopic eruption of permanent fist molar.
• In cases with early loss of deciduous mandibular canine since space closure occur because of drifting of incisors.

Space Regaining in Maxillary Arch

• In maxilla it is easy as compared to mandible.
• If space loss occurs due to mesial tipping removable appliances are used.
• If space loss is more than 3 mm fixed appliances are used.

Space Regaining in Mandibular Arch

• Removable appliances are less useful in regaining space in mandible.
• Lip bumper is used.

Description of Space Regainer

Gerber Space Regainer

• It is a fixed space regainer.
• It can be fabricated directly in mouth or in laboratory.
• Orthodontic band is selected for abutment tooth and is fitted.
• This space regainer consists of a U-shaped hollow tube and a U-shaped rod that enters the tube.
• The tube is soldered on the mesial aspect of the 1st permanent molar to be moved distally.
• The U-shaped rod is fitd into the tube in such a way that the base of U-rod contacts the tooth mesial to the edentulous area.
• With coil spring: If appliance is used as spring loaded spring regainer, open coil spring should be placed between tube and tube slope. Length of coil spring should be 1 to 2 mm more than its existing length. This leads to activation of spring.
• Without spring: The wire U section is fitted in tube, appliance placed and wire section is extended to contact the tooth mesial to edentulous area. Assembly should be removed and is welded or soldered at this area. Add occlusal rests to reduce cantilever effect.

Space Regainer using the Jackscrews

It consists of split acrylic plate along with the Jackscrew in relation with edentulous space and this is retained by the use of Adam’s clasp.

Space Regainer using Cantilever Spring

Here distalization of molars is done by using the removable appliance which incorporate the simple finger spring.

Question 2. Write short note on serial extraction.
Or
Write briefly on serial extraction.
Or
Define serial extraction. Explain in detail various serial extraction methods.
Answer.

Serial Extraction Definition

“It is a procedure where some deciduous teeth followed by permanent teeth were extracted to guide the rest of teeth into normal occlusion”.

Serial Extraction Indications

• Class 1 malocclusion with presence of space discrepancy.
• In cases where lateral incisor is lingually erupted.
• Lateral incisor displacement causing midline shift
• In cases where primary canine get prematurely lost.
• Crowding associated with proclination.
• In cases where mandibular incisors get labially displaced.
• In cases with gingival recession of labially placed incisors.
• In absence of spacing in deciduous dentition.

Serial Extraction Contraindications

• Class 2 and 3 malocclusion with skeletal abnormalities.
• In spaced dentition
• Anodontia/oligodontia
• Open bite/deep bite
• Mid line diastema
• Class I malocclusion with minimal space deficiency.
• Unerupted malformed teeth (dilacerated)
• Extensive caries or heavily filed fist permanent molar.
• Mild disproportion between arch length and tooth material.

Serial Extraction Advantages

• Treatment is more physiologic: Forces to guide teeth in normal position.
• Psychological trauma is avoided.
• It eliminates or reduces the duration of multibonded fixed treatment.
• Better oral hygiene is possible thus reducing the risk of caries.
• Health of investing tissue is preserved.
• More stable results are achieved.

Serial Extraction Disadvantages

• Serial extraction requires clinical judgement.
• Treatment time is prolonged (2–3 years).
• Patient cooperation is needed.
• Tendency for developing tongue thrust in extraction spaces.
• There is risk of arch length reduction by mesial migration of the buccal segment.
• Extraction of buccal teeth can cause deep bite.
• Axial inclination of teeth after serial extraction treatment requires short-term fixed appliance therapy.

Serial Extraction Diagnosis

• Study model analysis: There should be Carey’s analysis for mandibular arch and arch perimeter analysis for maxillary arch.
• OPG should be done to evaluate eruption status of the dentition.
• Cephalometrics: To assess the skeletal tissues to study the underlying skeletal relationship.
• For soft tissue examination both clinical examination and cephalograms are done.

Serial Extraction Procedure

• Dewel’s method
• Tweed’s method
• Nance method

Dewel’s Method

It is a three-step procedure

• Step 1: Extraction of deciduous canine to create space for alignment of the incisors (8-9 years of age).
• Step 2: Extraction of deciduous fist molar to accelerate the eruption of fist premolar (one year later).
• Step 3: Extraction of erupting fist premolar to permit the permanent canine to erupt.

Modified Dewel’s method

Here fist premolars are enucleated at the time of extraction of first deciduous molar especially in mandibular arch where canine erupts before fist premolars.

Tweed’s Method

• Step 1: Extraction of deciduous fist molar around 8 years of age.
• Step 2: Deciduous canines should be maintained as all the fist premolars are in advanced eruptive stage. Now both the deciduous canine are extracted along with all the four fist premolars.

Nance Method

This is the modified Tweed’s method

• Step 1: Extraction of deciduous fist molar around 8 years of age.
• Step 2: Extraction of all four fist premolars and deciduous canines simultaneously.

Post Extraction Therapy

Many of the cases of serial extraction need fixed orthodontic appliance therapy for correcting axial inclination and detailing of the occlusion.

Question 3. Define preventive and interceptive orthodontic. Describe serial extraction.
Or
Define preventive and interceptive orthodontics. Describe in detail the indications, contraindications, advantages, disadvantages and methods of serial extraction.
Or
Define serial extraction. Write about indications and contraindications of serial extraction procedure. Describe about the procedure of serial extraction.
Or
Define interceptive orthodontics. Describe in detail the indication, contraindication, advantages, disadvantages and methods of serial extraction.
Or
Define preventive and interceptive orthodontics. Write in detail about serial extraction in orthodontics.
Or
Define interceptive orthodontics. Describe in detail about serial extraction.
Or
Define interceptive orthodontics with examples. Describe in detail the indications, contraindication, advantages, disadvantages and techniques of serial extraction.
Answer.

Definition of Preventive and Interceptive Orthodontics

Preventive orthodontics is defied as “the action taken to preserve the integrity of what appears to be normal occlusion at a specific time”.

Interceptive orthodontics is defied as “that phase of the science and art of orthodontics employed to recognize and eliminate potential irregularities and malpositions of the developing dentofacial complex”.

Example of Interceptive Orthodontics

• Removal of supranumerary tooth.
• Removal of ankylosed tooth.
• Equilibration of occlusal disharmonies.
• Correction of developing cross bite.
• Control of abnormal habits by Serial extraction, Muscle exercises, space regainer, interception of skeletal malrelation.
• Disking.
• Thorough early straightening of permanent incisors.
• Removal of soft tissues or bony barrier to enable eruption of teeth.

Question 4. Write short note on Dewel’s method of serial extraction.
Answer. Dewel proposed a three step serial extraction procedure in 1978. This is the most satisfactory order in most patients even today.

Step 1: Extraction of Deciduous Canines

• In this step, the deciduous canines are extracted at around 8–9 years to create space for the alignment of the incisors.
• The main objective of extracting primary canines is to establish the integrity of upper and lower incisors. This prevents the development of lingual crossbite of maxillary laterals and resultant mesial migration of maxillary canines.

Step 2: Extraction of Deciduous First Molars

• In this step, deciduous fist molars are extracted when first premolars reach half of the root length as evidenced by radiographs. This would be some 12 months after the extraction of deciduous canines at around 9–l0 years of age.
• The objective of deciduous fist molar extraction is to accelerate the eruption of fist premolars. This ensures that the fist premolars emerge into oral cavity, before the eruption of permanent canines.

Step 3: Extraction of First Premolars

• In this step, first premolars are extracted as they are emerging into oral cavity and when the permanent canines have developed beyond half of the root length.
• Extraction of fist premolars facilitates proper eruption and alignment of permanent canines.
• After serial extraction procedure, the teeth are fairly aligned. However, the establishment of proper intercuspation\usually requires orthodontic mechanotherapy of minimal duration, although it may not be necessary in some cases.

Question 5. Write short note on interceptive orthodontics.
Answer. It is defined as “that phase of science and art of orthodontics employed to recognize and eliminate potential irregularities and malpositions in developing dentofacial complex”.

Interceptive procedures are the measures undertaken to prevent the potential malocclusion from progressing to more severe one.

Procedures undertaken in interceptive orthodontics are:

• Serial extractions
• Correction of developing crossbite: anterior and posterior
• Control of abnormal habits
• Space regaining
• Muscle exercises
• Interception of skeletal malrelation
• Removal of soft tissue or bony barrier to enable the eruption of teeth
• Extraction of supernumerary or ankylosed teeth

Serial Extractions

• It is an interceptive orthodontic procedure which consists of planned extraction of certain deciduous teeth and later on the specific permanent teeth in orderly sequence and predetermined pattern to guide the erupting permanent teeth at their most favorable position.
• Three of the popular methods in serial extraction are Dewel’s method, Tweed’s method and Nance method.
• Dewel’s method is the popular methods of all the above given methods.
• Following is the Dewel’s method. It is a three-step procedure:
  • Step 1: Extraction of deciduous canine to create space for alignment of the incisors (8-9 years of age).
  • Step 2: Extraction of deciduous fist molar to accelerate the eruption of fist premolar (one year later).
  • Step 3: Extraction of erupting fist premolar to permit the permanent canine to erupt.

Correction of Developing Crossbite

Anterior crossbite should be intercepted and treated at an early stage, if lef untreated it can cause severe skeletal malocclusion. Dentoalveolar anterior crossbites are best treated by tongue blade therapy. Skeletal anterior crossbites are best treated by myofunctional appliances. Functional anterior crossbite is treated by eliminating occlusal prematurities.

Control of Abnormal Habits

• Habit refers to the certain action involving the teeth and various other oral and perioral structures which are repeated enough by some patients to have profound and deleterious effect on position of teeth and occlusion.
• Some of the effects which affect the oral structures are thumb sucking, tongue thrusting and mouth breathing.
• Thumb sucking: It is the most frequently practiced habit by the children and causes damage to dentoalveolar structures. Presence of this habit upto 21/2 to 3 years of age is quite normal. If this habit remains till 31/2 to 4 years, it can damage the dentoalveolar structures and should be intercepted. This habit is intercepted by using habit breakers which are of removable type or the one which is fixed.
• Tongue thrust: It is defied as the condition in which tongue make contact with any teeth anterior to molars during swallowing. It leads to open bite and anterior proclination. This habit should be intercepted by habit breakers. Patient should be trained and educated over the correct technique of swallowing.
• Mouth breathing: This has profound effect on dentofacial region. It affects orofacial equilibrium due to lowered mandibular and tongue posture and therefore produce severe malocclusion. Here interceptive procedure consists of identification and removal of the cause. If oral habitual breathing persists vestibular screen is used to intercept the habit.

Space Regaining

Space regaining should be done at early age before eruption of second molar.

This can be done by using following appliances, i.e:

• By using cantilever spring: Space lost due to mesial drifting of permanent molar as well as distal drifting of deciduous first molar when deciduous molar get lost prematurely, this is regained by use of two finger springs.
• By using jack screw: Space is regained by use of removable orthodontic appliance which has jack screw in a way which increases the arch length which is obtained by distalization of molar.
• Gerber space regainer: It is an orthodontic molar band which is used for the tooth which has to be distalized. It consists of a U shaped hollow tubing.

Muscle Exercises

Presence of the normal orofacial muscle function is very essential for the development of normal occlusion.

These aberrant muscle functions are improved by various muscle exercises:

• Exercise for masseter muscle strengthening: Ask the patient to clench the teeth and count to 10 and now relax and repeat this over some period of time.
• Exercise for lips and cheeks: Ask the patient to hold a piece of paper between lips which maintain the lip seal by stretching the upper lip, holding and swishing the water behind the lips.
• Exercises for the tongue: For this there is one elastic and two elastic swallow. Hold pull exercise and tongue hold exercise is done.

Main limitation of these muscle exercises is that they are not the substitute for the corrective orthodontic therapy, and of they are not done correctly, they can be counterproductive also.

Interception of Skeletal Malrelation

They are treated by taking the advantage of growth potential of an individual and using the myofunctional appliances and orthopedic appliances such as head gears and chin cups.

Removal of Soft Tissue and Bony Barrier

It involves excision of soft tissue as well as removal of bone covering the crown of unerupted tooth for making the space so that tooth can erupt easily.

Extraction of Supernumerary and Ankylosed Teeth

These teeth should be extracted so that the path of eruption of permanent teeth is not obstructed by them.

Question 6. Write short note on interceptive and preventive orthodontics.
Answer. Preventive orthodontics is defied as “the action taken to preserve the integrity of what appears to be normal occlusion at a specific time”. Graber

Interceptive orthodontics is defied as “that phase of the science and art of orthodontics employed to recognize and eliminate potential irregularities and malpositions of the developing dentofacial complex”. Graber

• Number of procedures taken by an orthodontist to intercept the malocclusion which is developing.
• Unlike the preventive orthodontic procedures which are aimed at the elimination of factors which can cause malocclusion.
• Interceptive orthodontics is taken at a time when malocclusion is already developed or developing. So, interceptive orthodontics refers to the measures undertaken to prevent potential malocclusion from progressing into more severe one.
• Preventive orthodontic procedures are undertaken when both the dentition and occlusion are perfectly normal while the interceptive procedures are undertaken when signs and symptoms of malocclusion are appeared.
• Some of the procedures which are carried out in the preventive orthodontics can also be carried out in interceptive orthodontics but their timings are totally different.