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Presentation on theme: "LECTURE 6 INGRID REED DDS, MS DEPARTMENT OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS Canine Impactions Ectopic Eruption 1."— Presentation transcript:


2 Impacted vs. Ectopic eruption Impacted Condition of being firmly lodged (impacted in alveolar bone) or wedged by a physical barrier, usually other teeth, so it is prevented from erupting Ectopic eruption Located away from the normal position 2

3 Eruption process 3 Permanent tooth erupts Resorption of overlying bone Resorption of 1° tooth roots Eruption through gingiva

4 Interference with eruption 4 Ectopic eruption of permanent tooth Undermining resorption of the 1° tooth Non- resorption of 1° roots, may be result not cause Supernumerary teeth – remove as indicated Heavy fibrous gingiva – may need to expose tooth Sclerotic bone – may need to expose tooth Ankylosed tooth Lack of space – consider serial extraction or orthodontics (age/crowding dependent)

5 Normal Development of Maxillary Canines Age 3 – located high in maxillary bone –mesially & lingually directed crown Intrabony migration – lateral roots – ugly duckling Spontaneous closing of midline diastema as canines simultaneously upright and erupt 5

6 4-6 months Development (calcification) begins high in the maxilla 6 yearsCrown completed 10 years Palpable high in the buccal vestibule 11-13yearsEruption yearsRoot completed 6

7 Prevalence of Maxillary Canine Impaction Maxillary canine 2 nd most frequently impacted tooth Third molars most frequently impacted Maxillary 50 times greater than mandibular Palatal versus buccal - range 2:1 to 12:1 7

8 Etiology - Maxillary Canine Impaction Availability of space in arch Eruption path Horizontal angulation of tooth Trauma to 1° tooth bud Disturbance in eruption sequence Rotation of tooth buds Premature root closure 8

9 9

10 Maxillary Canine Impaction – Diagnostic Problem Usually last tooth to replace primary tooth Fewer radiographs taken at recall – bitewings may not show canines Need knowledge of crown development, root development and eruption 10

11 Impacted Maxillary Canines The most opportune time to observe the maxillary canines beginning their eruption and detect an eventual impaction is when children are ~ years of age, when the maxillary canines migrate labially 11

12 Overretention of Primary Canines Canine erupts years Primary canine not exfoliated, overretention may be result of, not cause of, ectopic position of canine Permanent canine has not precipitated vertical resorption of the primary tooths root Canine crown inclined too far mesially Canine crown having slipped over the root of the permanent lateral incisor, is deprived of the eruptive guidance of the lateral incisors distal surface 12

13 Extraction of Primary Canines Canines begin to deviate from a normal eruptive position in patients ~9 years of age If permanent canine path is errant, extract primary canines at age 10. Teeth take the path of least resistance Improvement usually seen in 6-18 months 13

14 Extraction of Primary Canines Degree of horizontal angulation important Study by Ericson an Kurol 78% of canines changed angulation within 18 months of 1° canine extraction 91% if tip of canine cusp had not passed midline of lateral root Must have space for canine to erupt- maintain or create after primary extraction. 14

15 Sequence of Eruption Permanent Teeth MAXILLARYMANDIBULAR First molar Central incisor Lateral incisor First premolarCanine Second premolarFirst premolar CanineSecond premolar Second molar

16 Clinical Signs of Maxillary Canine Impaction Clinical signs 1. Failure to palpate canine bulge in buccal vestibule by 10 years 2. Immobility of the deciduous canine 3. Palatal bulge indicating possible underlying canine 4. Increased mobility, non-vital central or lateral incisors 5. Inadequate space within the dental arch for canine eruption 6. Flared lateral incisors – can also be normal 7. Asymmetry of eruption 1. Impacted maxillary canines in individuals > 40 years susceptible to ankylosis 2. Failure of movement in an adolescent indicates ankylosis 16

17 Lack of Space 17

18 18

19 NA Lack of space for canines 19

20 9 years 4 months NA 20

21 Screening panoramic radiograph Dental age 8-9 Full eruption of Maxillary central and lateral incisors Mandibular central and lateral incisors All four first molars Anytime prior with cause 21

22 Radiographic Signs of Probable Canine Impaction Long axis of the canine is angled more than 10 ° to the vertical plane. The greater the angle the more likely a problem. 25° - impaction Canine overlaps the lateral or central incisor root Parallax technique shows buccal/palatal position 22

23 Clarks rule – Horizontal change The lingual object moves in the same direction as the x-ray source The buccal object moves in the opposite direction of the x-ray source because it is farther away from the film than the root of the lateral incisor 23

24 24

25 25

26 26

27 27

28 28

29 29 10/31/05 Age 9 yrs 3 mos Patient A

30 30 Patient A 40°

31 31 2 yrs 5 mo later Age 11 yrs. 8 mos Patient A

32 32 Age 12yrs. 7 mos Patient B

33 33 4 years 3 months later Age 16 yrs 10 months Patient B

34 34

35 35

36 36

37 37

38 38 Mandibular canine impactions Mandibular canine impaction

39 Management of Impacted Canines Extract Deciduous Canine Age 10 May help normalize eruptive path in palatally displaced canine Radiographic improvement in 6-18 months No Treatment Poorly motivated patient Inform of resorption risk and cystic change within canine follicle Monitor radiographically every 12 months Orthodontic Alignment Following surgical exposure Gold chain bonded to the tooth Space created TPA in place Surgical Removal Very unfavorable canine position Poorly motivated patients Orthodontic treatment contraindicated Severe crowding (substitute 1 st premolar) 39

40 Impacted teeth - considerations 40 Surgical exposure Attachment to the tooth Orthodontic mechanics to bring the tooth into the arch

41 41 KF

42 42 KF 4/13/07

43 43 KF 12/1/07

44 44 KF 8/7/08

45 45 KF

46 46 KF

47 KF

48 48

49 49 Impacted second molar

50 OUT OF NORMAL POSITION Ectopic Eruption 50

51 Ectopic Eruption Maxillary first molars Maxillary canines Mandibular canines Maxillary premolars Mandibular premolars Maxillary lateral incisors 51

52 Ectopic eruption 52 Malposition of a permanent tooth bud Eruption in the wrong place Most common – maxillary first permanent molars Ectopic eruption of other teeth rare but can lead to transposition pgs 139, ,

53 Ectopic eruption 53 Permanent tooth causes resorption of tooth other than the one it is supposed to replace or Resorption of an adjacent permanent tooth

54 Lateral incisors 54 Ectopic eruption causes resorption of primary canine – indicates lack of space Loss of only one primary canine can cause midline shift – need to maintain lateral incisor position with appliance or Extract contralateral canine Loss of mand. 1° canines causes incisors to tip lingually with loss of arch perimeter Space analysis important – passive LLA or active LLA

55 55 Prevalence2-6% (20-25% if cleft lip/palate) Etiology Crowding / large crown / mesial eruption MANAGEMENT OBSERVEActive Treatment May correct spontaneously Rarely after age 8 years Brass wire or elastic separator – mild cases Distalizing appliances more serve cases Extract primary if pulpal involvement – space maintainer or regainer Ectopic Maxillary First Molar

56 56 Age 8yr. O months Patient Y

57 57 Patient Y

58 58 8 years 2 months Patient Z

59 59 6 weeks Patient Z corrected

60 60 Age: 7 years 8 months Missing 2 nd premolars

61 DOB , Pano age 7 years 8 monthsW.E. 61

62 W.E. 62

63 Transposed Teeth S.N. 63

64 Early Loss of Primary Teeth 64 Early loss of 2 nd 1° molar Mesial drift of first permanent molar Greater if no occlusal forces are on it Early loss of 1° first molar or canine Distal drift of incisors Force from active contraction of transseptal fibers Pressure from the lips and cheeks pgs –


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