MIDLINE DIASTEMA

Presented by: Anamika Thorat

CONTENTSDefinitionCauses of Midline DiastemaDiagnosisManagement of Midline Diastema

DEFINITION Definition of Diastema: Diastema is defined as a space between adjacent teeth. Definition of Midline Diastema: Midline diastema refers to anterior midline spacing which is greater than 0.5 mm, between the two central incisors.

CAUSES OF MIDLINE DIASTEMA

1) Transient Malocclusion A midline spacing can occur during the mixed dentition period associated with the eruption of permanent canines.This stage is called as ugly duckling stage,corrects itself as the developing permanent canines erupt further.(Broadbent phenomenon)

2) Tooth material arch length discrepancy: Conditions such as missing teeth,microdontia,peg shaped laterals,macrognathia,extractions with resultant driftring of adjacent teeth may affect midline diastema.3) Unerupted Mesiodens: Presence of an unerupted mesiodens between the two central incisors also predispose to midline diastema.

Microdontia Unerupted mesiodens

4) Abnormal frenal attachment: The presence of a thick and fleshy labial frenum can give rise to midline diastema.5) Proclination: Proclination of a teeth as a result of habits such as thumb sucking or tongue thrusting can cause midline diastema along with genralised spacing.

Abnormal frenum attachment Proclination

6) Midline Pathology: Soft tissue and hard tissue pathologies such as cysts,tumors,odontomes may cause midline diastema.

7) Iatrogenic cause: Midline diastema can occur when certain therapeutic procedures such as rapid maxillary expansion are undertaken.

8) Racial predisposition: Presence of midline spacing also has a racial & familial background.The negroid race shows the greatest incidence of midline diastema.9) Ectopic maxillary canines: Absence of canines from their normal position can facilitate distal drift & tilt of incisors with space opening & there is the associated lack of physiological pressures to upright the lateral & central roots that normally closes the diastema.

DIAGNOSIS A proper history and clinical examination

should be done. Measure the mesiodistal width of the teeth

which will help in determining the tooth material-arch length discrepancy.

Blanch test-done by pulling the upper lip outwards.Presence of a thick & fleshy frenum is confirmed by the blanching of the tissue in the incisive papilla region palatal to central incisor.

` Check for any precious oral habit. Periapical radiograph-Presence of notching in the

interdental alveolar bone as seen on a radiograph is also diagnosing midline pathology that cause spacing.

MANAGEMENT OF MIDLINE DIASTEMA

Treatment of midline diastema is done in three phases:1) Removal of cause2) Active treatment 3) Retention.

1)REMOVAL OF CAUSE: First phase involves removal of the etiology. Habits should be eliminated using fixed or

removeable habit brekers.ETIOLOGY TREATMENT PLAN

• Normal developing dentition(ugly duckling stage)

• Self correcting after the eruption of permanent canines.

• Spontaneous closure seems to occur with less frequency in-

a) generalised sparing b) Initial diastema of more than 3 mm.

• Familial incidence • Appliance therapy

• Parafunctional habits -flaccid lips & poor muscle tone.

a)Correction of the habits has been known to spontaneously correct the diastema.

ETIOLOGY TREATMENT PLAN-tongue thrust may cause anterior open bite & diastema -thumb/digit sucking over a prolonged period.

b)In cases of excessive diastema,correction of the diastema can be simultaneously carried out with the habit breaking appliance.

• Tooth size discrepanciesa) Excessive anterior vertical

overlap.b) Excessive vertical maxillary

alveolar growth.c) Retrognathic mandible or a

prognathic mandible

• First intrusion of the maxillery incisors followed by retraction of incisors to close the diastema.

• If however cephalogram indicates an excessively long lower face or a class 3 growth trend.functional therapy may be the treatment of choice.

• Frenal attachments • Generally advocated that the diastema should be closed as far as possible before going in for frenectomy.the reason cited is that the surgery be performed before,the surgical scar tissue maintains the diastema.

• Mesio-distal angulation of teeth.

• the correction of the crown angulation(tipping)will close the diastema.

ETIOLOGY TREATMENT PLAN• Tooth anomalies

(supernumerary tooth,peg laterals,absence of laterals)

• Supernumerary-removal of the supernumerary followed by a closure of the diastema is done.

• Peg shaped laterals-the diastema can be corrected orthodontically followed by esthetic restoration of the peg shaped laterals.

• Absence of laterals-a)The space for missing laterals if detected early,may be initially be maintained and at later that be replaced with fixed prosthesis.b)Another option is to orthodontically more the canine into the space of the missing laterals,followed by a carefull recountring of the cuspid &the first bicuspid.

• pathological • Systemic phase (if required) followed by appilance therapy.

ETIOLOGY TREATMENT PLAN• Unerupted mesiodens • Extraction

Second phase-active treatmenta) It can be done using removeable appliances

or fixed appliances.b) The principle applied here is of reciprocal

anchorage(in fixed)c) The types of movement are either bodily or

more commonly by tipping.

2)REMOVEABLE APPLIANCES An active plate can be utilized for this

purpose.the plate incorporates palatal finger springs passing distally to the central incisors, such that the loop is opposite to the direction of movement.

A split labial bow is a modification which can be utilized to close the diastema,(made up of 0.7mm hard stainless steel wire.

Disadvantage-space may be created between the laterals. in split labial bow,bows are extended upto the buccal aspect of the opposite central incisors.

In cases where there is an increased overjet accompying the diastema, a hawley’s plate with an active labial bow can be used to retract the incisors & thus close the space.

Drawback of using removeable appliance- only tipping movements can be achieved.

3)FIXED APPLIANCES Fixed appliance incorporating elastics or

springs bring about the most rapid correction of midline diastema.

Elastics can be streched between the two central incisors in order to close the space.

M shaped springs incorporating helices can be inserted into the central incisors brackets.the spring is activated by closing the helices.

A stainless steel band with a bracket or more commonly a bracket may be banded to tooth and elastics utilised to bring the central incisors towards each other.

For the purpose of bodily movement of the teeth, it is suggested than an edgewise bracket with a simple looped partial archhwire made from a retangular wire be tied under the tension into both the brackets.

Midline diastema treated with fixed appliances:

Third phase of treatment involves retaining the treated malocclusion.

4)RETENTION Midline diastema is easy to treat but difficult

to retain. In order to prevent a relapse,a long term

retention is required in these cases.

Most orthodontic recommended long term retention using suitable retainers.

Since prolonged retention is indicated,it is advisable to use lingual bonded retainers.

The other retainers that can be used include bonded retainers & hawley’s retainer.

OTHER TREATMENT MEASURES

Role of cosmetics restorations:a) Esthetic composite resins are generally

used to close the midline diastema especially in adult patients.

b) It requires gradual composite build up on the mesial surface & stripping of the distal surface of central & lateral incisors in order to achieve a natural shape & size of teeth.

COMPOSITE BUILD UP:

a)Composite build up on mesial aspect of the central incisors & stripping of the distal surface-

b)Composite build up on the mesial aspect of the lateral incisors & stripping of the distal surface-

c)Composite build up on the mesial aspect of the canines-

Prosthesis/crowns:a) Presence of peg shaped laterals or teeth

with other anomalies of shape & size require prosthetic rehabilitation.

b) Missing teeth should be replaced with fixed or removeable prosthesis.

c) Crowns on central incisors can close a midline.

CONCLUSION

Midline diastema although being a transient condition become persistent at times which needs to be treated with special care & concern due to the high propencity of relapse.

Treating midline diastema efficiently & effectively is important for overall well being of individual as it affects the esthetics of the person & has an important effect on overall personality of an individual.

Effective diastema treatment requires correct diagnosis of its etiology & intervention relevant to the specific etiology.

Correct diagnosis includes medical & dental histories, radiographic & clinical examinations, and possibly tooth size evaluations.

Timing is often important to achieve satisfactory results.

RECENT ADVANCES IN CLOSURE OF MIDLINE DIASTEMA:

Direct closure with composite layering technique.

Laminate veneers. Adhesive Restorations. Micro magnetic retainers.

REFRENCES

Textbook of Pedodontics ; Shobha Tandon ; 2nd edition

Textbook of Orthodontics ; S. I. Bhalajhi ; 6th edition