The document discusses midline diastemas, which are spaces between the two central incisors. It defines midline diastemas and discusses their various etiologies such as normal development, tooth material deficiencies, physical impediments like habits or retained primary teeth, and iatrogenic causes from procedures like rapid maxillary expansion. The diagnosis involves a clinical exam and radiographs to identify the cause. Treatment involves removing the cause, using appliances to close the space, and retainers to maintain results. Midline diastemas can be aesthetically improved through various orthodontic or restorative techniques.

1. MIDLINE DIASTEMAPresented by :-Dr. Manish KumarBapuji Dental College & Hospital, Davangere1

2. CONTENTS:-INTRODUCTIONDEFINATIONETIOLOGYDIAGNOSISMANAGEMENTCONCLUSIONREFERENCES2

3. INTRODUCTIONFrom the beginning of time people have noticed the prominent spaces in their dentitions.

4. In France, the teeth on either side of a space or gap are called ‘‘dents du bonheur’’ or ‘‘lucky teeth’’

5. Thus there are wide variations of perception in different cultures and ethnic background.

6. Maxillary midline diastemas are one of the common complaints encountered.

7. It has been defined as a space greater than 0.5 mm between the proximal surfaces of adjacent teeth 3

8. DEFINATION OF DIASTEMA A space between adjacent teeth is called a diastema.DEFINATION OF MIDLINE DIASTEMAMidline diastema refers to anterior midline spacing between the two central incisors.4

9. ETIOLOGY OF MIDLINE DIASTEMANORMAL DEVELOPING DENTITIONPhysiologic median diastema/ ugly duckling stageEthnic and familialImperfect fusion of midline of premaxilla2. TOOTH MATERIAL DEFICIENCYMicrodontiaMacrognathiaMissing lateralPeg lateralsExtracted tooth5

10. 63. PHYSICAL IMPEDIMENTRetained deciduous MesiodensAbnormal labial frenumMidline pathologyDeep bite4. HABITSThumb suckingTongue thrustingFrenum thrusting5. ARTIFICIAL CAUSESRapid maxillary expansionMilwaukee braces6. RACIAL PREDISPOSITION

11. 1. NORMAL DEVELOPING DENTITION7a) Physiologic median diastema/ ugly duckling stageIt is a transient or self correcting malocclusion which is seen in the maxillary incisor region between 8-9 years. It is particularly seen during the eruption of the permanent canines.

12. As the permanent canines erupt they displace the roots of the lateral incisors mesially.

13. This causes a divergence of the crowns of the two central incisors causing a midline spacing.

14. This was described by Broadbent as the ugly duckling stage as children tend to look ugly during this phase of development. So it also known as Broadbent phenomenon.

15. It is a self correcting anomaly.8

16. 9b) Ethnic and familialCertain group of peoples, especially negroid groups exhibit median diastema as an ethnic norm.

17. Median diastema is seen in some families also.c) Imperfect fusion at the midlineMedian diastema occurs due to imperfect fusion at the midline of the premaxilla.

18. A V-shaped or W shaped osseous septum may be associated with this condition.2. TOOTH MATERIAL DEFICIENCY10a) MicrodontiaMicrodontia refers to teeth that appear smaller in size compared to normal.

19. In this case the jaw size is normal but the size of the teeth is small which produces diastema between the teeth.

20. Microdontia is most frequently seen in Down’s syndrome and ectodermal dysplasia.11b) macrognathia It is a developmental anomaly characterized by an abnormal large jaw.In this case the size of the tooth is normal but because of the increase in size of jaw, it results in diastema.c) Missing lateral.Due to the missing lateral there will be tooth material-arch discrepancy as a result there will be drifting of adjacent teeth.d) Extracted toothThis also results in tooth material-arch discrepancy which causes drifting of adjacent teeth.

21. 3. PHYSICAL IMPEDIMENT12a) Retained deciduous teeth.This causes ectopic eruption of tooth and formation of median diastema.b) MesiodensPresence of an unerupted mesiodens between the two central incisors also predispose to midline diastema.

22. 13c) Abnormal labial frenumThe presence of a thick and fleshy labial frenum can cause a midline diastema.This type of fibrous attachment can prevent the two maxillary central incisors from approximating each other.d) Midline pathologySoft tissues and hard tissue pathologies such as cysts, tumors and odontomes may cause midline diastema.

23. 4. HABITS14a) Thumb suckingThumb sucking is defined as placement of the thumb or one or more fingers in various depths into the mouth.

24. It can cause severe proclination of the maxillary anterior teeth along with formation of diastemab) Tongue thrustingThis is a condition in which the tongue makes contact with any teeth anterior to the molars during swallowing.

25. It also causes proclination of anterior teeth along with diastema and open bite.c) Frenum thrustingThis habit is a self injurious habit.

26. If the maxillary incisors are slightly spaced apart, the child may lock his labial frenum between these teeth and permit it to remain in this position for several hours.15

27. 5. ARTIFICIAL CAUSES/ IATROGENIC CAUSES16a) Rapid maxillary expansionOriginally rapid maxillary expansion at the mid palatal suture was recommended to help meet this goal.

28. With rapid expansion at a rate of 0.5 to 1 mm/day 1 cm or more of expansion is obtained in 2 to 3 weeks.

29. A space is created at the mid-palatal suture which is filled initially by tissue fluids and hemorrhage, and the expansion is highly unstable.

30. The opening of the mid-palatal suture is fan-shaped or triangular with maximum opening at the incisor region and gradually diminishing toward the posterior part of the palate.

31. As a result there is incisor separation and a midline diastema is formed.

32. This diastema closes as a result of the trans-septal fibre traction.b) Milwaukee braces

33. 17A, Bilateral constricted maxilla with upper midline shift; B, type 1 RME appliance in mouth;C, end of expansion; D, correction of upper midline shift at end of retention period.