WELCOME

PRESENTATION ON

“ORAL SCREEN AND OTHER MIXED DENTITION APPLIANCE”

Submitted to :

Dr. Anjuman Ara Akter Dr. AKM Asad Polash

Department of Orthodontics &Dentofacial Orthopedics

Dental Unit,Rajshahi Medical College

Prepared by:Name: A.K.M

Mahbubar RahmanBatch: 24th B.D.S.

Roll No. : 05Session:2012-2013

CONTENT

Mixed Dentition.

Points to be noted in mixed dentition.

Orthodontic problems in mixed dentition.

Orthodontic

appliances used in mixed

dentition.

WHAT IS MIXED DENTITION

Combination of primary and permanent teeth, usually present between ages of 6 to 13 years when primary teeth are being replaced by the permanent teeth; starts with the eruption of the first permanent tooth and ends with the shedding of the last deciduous tooth.

Mixed Dentition

The mixed dentition period can be classified into three groups:

1. First transitional period. 2. Inter-transitional period.

3. Second transitional period.

First transitional period:This period is characterized by emergences of the 1st

permanent molars and the exchange of the deciduous incisors with permanent incisors.

The first permanent molars are guided into the dental arch by the distal surface of the upper and lower second deciduous molars. This mesio-distal relation between the distal surface of the upper and lower second deciduous molars can be of 3 types:

A. Flush terminal plane. B. Distal step terminal plane. C. Mesial step terminal plane.

B. Distal step terminal plane. C. Mesial step terminal plane.

Inter-transitional period:In this period the maxillary and mandibular arches consist of sets of

deciduous and permanent teeth.

The second transitional period:The second transitional period characterized by the replacement of the deciduous molars and canines by the premolars and permanent

cuspids respectively.

POINTS TO BE NOTED IN MIXED DENTITIONSTAGE

When we are 6 years old, the first permanent molars will erupt behind the deciduous molars. This tooth is also called the 'Six-year Molar'. We have to remember to clean our 'Six-year Molars' when brushing, otherwise it will get decay in the tooth and illness in the gum tissues.

Commonly, the wobbly teeth will fall out naturally, and there is no need to extract them. Because early loss of deciduous teeth will lead to irregular permanent teeth.

To avoid gum inflammation, we need to gently brush the wobbly teeth too.

ORTHODONTIC PROBLEMS IN MIXED DENTITION

Increase over jet & open bite. Malallignment of ant teeth. Narrow upper arch & bilateral

posterior cross bite. Developing anterior cross bite. Crowding.

ABOVE PROBLEMS ARISE DUE TO

(i) Presence of carious lesion: i-e. Proximal caries, nursing bottle caries.

(ii) Premature loss of deciduous teeth.(iii) Presence of supernumerary teeth, extra teeth,

missing teeth.(v) Ankylosed deciduous teeth.(vi) Presence of abnormal oral habits: Thumb sucking,

tongue thrusting etc.(vii) Prolonged retention of deciduous teeth.(viii) Abnormal labial frenum. (ix) Deeply locked 1st permanent molars.

PERCENTAGE OF MALOCCLUSIONS IN EARLYMIXED DENTITIONS

Study by Keski-Nisula et al Dec 03: 92.7 % some disharmony present. 67.7% malocclusion. 52.4% Class ll type. 1.5% Class lll type. 30.1% Asymmetrical Bite.

THE BENEFITS OF EARLY TREATMENT IN MIXED DENTITION

For those patients who have clear indications for early intervention, early treatment presents the opportunity to: Influence jaw growth in a positive manner. Harmonize width of the dental arches. Improve airway/speech problems. Correct harmful oral habits. Preserve/gain space for erupting permanent teeth. Improve aesthetics and self-esteem. Simplify and/or shorten treatment time for later corrective

orthodontics.

There are a number of procedures that can be undertaken at mixed dentition period to prevent and intercept a malocclusion that is developing known as preventive and interceptive orthodontics respectively.Preventive orthodontics: 1. Parent education. 2. Caries control. 3. Management of ankylosed teeth. 4. Maintainance of quadrant wise shedding time. 5. Check up for oral habits. 6. Extraction of supernumerary teeth. 7. Space maintenance.

Interceptive orthodontics:

1. Serial extraction. 2. Correction of developing crossbite. 3. Control of abnormal habits. 4. Space regaining. 5. Muscle exercises. 6. Interception of skeletal malrelation. 7. Removal of soft tissue or bony barrier to enable eruption of teeth.

ORTHODONTIC APPLIANCES USED IN MIXED DENTITION

1. Myofunctional Appliances. -Bite plane. -Oral screen. -Lip bumper. -Activator. -Frankel’s regulator.2. Tongue guard. 3. Space maintainer.4. Tongue blade therapy.5. Space regainer.

MYOFUNCTIONAL APPLIANCE Functional appliances are defined as loose fitting or

passive appliances,which harness natural forces of the oro-facial musculature that are transmitted to the teeth and alveolar bone through the medium of the appliance.

Functional appliances are used for growth modification procedures that are aimed at intercepting and treating jaw discrepancies.They can bring about following changes :

1. An increase or decrease in jaw size. 2. A change in spatial relationship of the jaws. 3. Change in direction of growth of jaws. 4. Acceleration of desirable growth.

TREATMENT PRINCIPLESFunctional appliances work on 2 broad principles :

1. Force application. 2. Force elimination.

1. Force application : Compressive stress and strain act on the structures involved and result in a primary alteration in form with a secondary adaptation in function2. Force elimination: This principle involves the elimination of abnormal and restrictive environmental influences on the dentition thereby

allowing optimal development.

ADVANTAGES AND LIMITATIONS OF FUNCTIONAL

APPLIANCES Advantages : 1. It enables elimination of abnormal muscle function . 2. Treatment can be initiated at an early age. 4. Less chair side time as these appliances are mostly fabricated at the laboratory. 5. The frequency of the patients visit to the orthodontist is less. 6. They do not interfere with oral hygiene maintenance. 7. Most functional appliances are worn during night.

LIMITATIONS : 1. They can not be used in adult patients in

whom growth has ceased. 2. They can not be used to bring about individual tooth movement. 3. Patient co-operation is essential for the success of the treatment. 4. Fixed appliance therapy may be required at

the termination of treatment for final detailing of the occlusion.

CASE SELECTION Age: The growth modification therapy using functional appliances is possible only in a growing patient. The optimum time in between 10 years of age and pubertal growth phase.

Social consideration : Functional appliances achieve there results with minimum supervision and can be worn safely for long periods without supervision. Patients who live far away from the clinic may benefit from these appliances.

CASE SELECTION Dental Consideration: An Ideal case for functional appliance therapy is one that is devoid of gross local irregularities like rotations and crowding. Only uncrowded cases can be treated by functional appliance.

Skeletal Consideration : Moderate to severe skeletal class II malocclusions are ideally suited for functional appliance treatment. Mild class III malocclusions with a reverse overjet and an average overbite, can be treatable with functional appliance.

Functional Appliances used in mixed dentition are:

1. Bite plane.2. Oral screen.

3. Lip bumper.4. Activator.5. Frankel’s regulator.

BITE PLANEBite planes are myofunctional appliances which are usually incorporated into the design of a removable orthodontic appliance as an extension or modification of the acrylic base plate.CLASSIFICATION: 1. According to their position as:

a) Upper anterior. b) Lower anterior. c) Upper posterior. d) lower posterior. 2.According to the angulation as:

a) Flat. b) Inclined.

Fig: Posterior Bite PlaneFig: Anterior bite plane

ORAL SCREEN

Oral screen is a myofunctional appliance introduced by Newell in 1912.

It is a thin sheet of acrylic base material which is fit into the buccal or labial vestibule of the mouth which acts as a screen between the teeth & the surrounding musculature. It is also known as vestibular screen.

FIG :- ORAL SCREEN

INDICATION OF ORAL SCREEN1) Correction of mouth breathing when the airway is

patent.

2) Correction of thumb sucking, tongue thrusting, lip biting, cheek biting.

3) Mild protrusion of upper anterior with spacing & incomplete bite.

4) Mild disto-occlusion with pre-maxillary protrusion & open bite in deciduous and mixed dentition.

5) In the presence of flaccid, hypotonic, oro-facial musculatures as muscle exerciser.

MANAGEMENT OF THE APPLIANCE:

The patient should be asked to wear the appliance at night and 2-3 hours during the day time.

 Patient is instructed to maintain lip seal during the first days the patient may show certain areas of irritation in the Sulcular and the frenal areas. Such areas of the appliance should be carefully trimmed to avoid tissue irritation. Breathings holes should be gradually reduced in size.

MODIFICATIONHotz modification:1.The oral screen can be fabricated with a metal ring

projecting between the upper & lower lips. This ring can be used to carry out various muscle exercises.

2. In patients who have tongue thrust habit and additional screen is placed on the lingual aspect of the teeth. This additional screen is attached to the vestibular screen by means of a thick wire that runs through the bite in the lateral incisor region.3. In case of mouth breathers the vestibular screen should be fabricated with a number of holes that are gradually closed in a phased manner.

Fig:- Modified Oral Screen

LIP BUMPERThe lip bumper or lip plumber as it is sometimes called is a combined removable-fixed appliance. The appliance can be used in both the maxilla and the mandible to shield the lips away from the teeth.

USE:1. They are used in patients exhibiting lower lip habits.2. They are used in patients exhibiting hyperactive mentalis activity

that causes flattening or crowding of the lower anteriors.3. Lip bumper can be used to augment anchorage.4. Distalization of the first molars.5. They can be used as space regainers if the lower molars have

drifted mesially due to early loss of deciduous molars.

Fig:- Lip Bumper

ANDRESEN APPLIANCE:

Also known as activator, as monoblock, Norwegian appliance.

 

Indication:

(i) Mild Class II division 1 malocclusion.(ii) Class II division 2 malocclusion after aligning the incisors. (iii) Mild Class III Cases - reverse activator can be used to correct the malocclusion. (iv) Class I deep bite & open bite cases .(v) Retrognathic mandible.

Fig:- Andresen appliance

Contraindication of Andresen appliance :1. The appliance is not used in correction of class I problems of crowed teeth.2. In children with excess lower facial height and extreme mandibular

growth.3. In children whose lower incisors are severely procumbent.4. In children with nasal stenosis.5. The appliance has limited application in non growing individuals.

FANKEL'S APPLIANCE

Also known as Functional Regulator (FR), oral gymnastics, vestibular appliance.

It works in 2 ways:

(i) Eliminate abnormal perioral muscle force.

(ii) Restrict muscle force of labial & buccal shield.

Fig:- Fankel's Appliance

TYPES & INDICATIONS OF FANKEL'S APPLIANCE

It is usually 5 types:1. Fr1

Fr1a - used in class I malocclusion where minor to moderate crowding. Fr1b - used in class II division 1. Fr1c - used in severe class II division 1.2. Fr2 - Class II division 2.3. Fr3 - Class III cases.4. Fr4 - correction of open bite & bimaxillary protrusion. 5. Fr5 - High mandibular plane angle & vertical maxillary excess incorporating with head gear.

TONGUE GUARD

It is a passive appliance & It may either removable or fixed. But we usually use removable tongue guard in mixed dentition period.

  Use: 1. The tongue guard limits the movement of

the tongue in between the front teeth. This allows the front teeth to erupt into a more normal position.

2. The tongue may rub against the tongue guard when it is initially filled. It may causes some sore spots on the tongue, which will pass approximately 2-3 weeks & causes some speech and eating difficulties during the initial phase.

Fig:- Tongue guard

Space maintainer

It is an appliance which maintains the mesiodistal width of the lost primary tooth and the lost function to an extent.

  Indication:

(i) Restoration of function.(ii) To prevent drifting of teeth and to maintain the space.(iii) Aesthetics.(iv) Psychological reasons.(v) To prevent sequelae of periodontal & caries problem.(vi) To prevent ectopic eruption of teeth.

Fig:- Space maintainer

CLASSIFICATION :

According to Hitchcock : 1. Removable or fixed or semi-fixed. 2. With bands or without bands. 3. Functional or non-functional. 4. Active or passive. 5. Certain combinations of the above.

CLASSIFICATION:According to Hinrichsen:1. Fixed space maintainers: Class I : a) Non functional types: (i) Bar type. (ii) Loop type. b) Functional types: (i) Pontic type. (ii) Lingual arch type. Class II : Cantilever type (distal shoe, band & loop.) 2. Removable space maintainers: Acrylic partial dentures.

TONGUE BLADE THERAPYDeveloping single tooth anterior cross bite can be successfully treated using a tongue blade. It can be used in case there is sufficient space for the tooth to be brought out. The tongue blade is flat wooden stick resembling an ice cream stick. It is placed inside the mouth contacting the palatal aspect of the tooth in crossbite. The blade is made to rest on the mandibular tooth in crossbite that act as a fulcrum and the patient is asked to rotate the oral part of the blade upward and forward. This is continued for 1-2 hours for about 2 weeks. Most developing cross bites that are recognized by a dentist at an early stage can be successfully treated by this form of therapy.

FIG :- TONGUE BLADE THERAPY

SPACE REGAINERA fixed or removable appliance capable of moving adisplaced permanent tooth into its proper position

in dental arch.

Indication:-1. One or more primary teeth is lost.2. Some space in the arch has been lost due

to mesial drift of the first permanent molar.

FIG:- SPACE REGAINER

Latest Findings- the challenges• June 2004 AJODO by Tullock et al – 1 phase of fixed orthodontics is more efficient than 2 phases with functional/fixed appliances.• September 2003 AJODO by O’Brian et al – Fully randomized study demonstrated clinically significant dento-alveolar changes with Twin Block. Effective at overbite/overjet reduction.• July 2003 EJO by Basciftci et al – the activator appliance can produce both skeletal and dental effects in the growingdentofacial complex.• January 2003 AJODO by Laecken et al – Retroactive study suggests that both skeletaland dental changes contribute to Class II treatment with the Herbst appliance with fossa remodelling.