DEVELOPMENT OF OCCLUSION IN PEDIATRIC DENTISTRY

HELLO VISITERS, IAM SAITEJA , BDS 3RD YEAR STUDENT FROM MNR DENTAL COLLEGE , SANGAREDDY. I AND MY BATCH HAS DEVELOPED A PPT ON DEVELOPMENT OF OCCLUSION IN PEDIATRIC DENTISTRY. PLEASE GO THROUGH THE PPT. EVERY TOPIC IS CLEARLY EXPLAINED IN THIS PPT ALONG WITH DIAGRAMS.

1. DEVELOPMENT OF OCCLUSION IN PEDIATRIC DENTISTRY UNDERSTAND THE GROWTH AND ALIGNMENT OF PRIMARY AND PERMANENT Teeth. BY CH.SAITEJA BDS 3 RD YEAR

2. INDEX INTRODUCTION What is occlusion? Different types of occlusion Periods of occlusal development PRE- DENTATE PERIOD DECIDUOUS DENTITION Classification of spaces Non-spaced dentition Anterior –teeth relationship Primate space Physiologic space Overjet and Overbite Canine to canine realtionship

3. MIXED DENTITION PERIOD Phases of mixed dentition First transitional phase Inter- transitional phase Second-transitional phase Leeway space of nance Ugly duckling stage PERMANENT DENTITION PERIOD Andrew keys of occlusion SELF –CORRECTING ANOMALIES REFERENCES

4. INTRODUCTION WHAT IS OCCLUSION? The term occlusion is derived from Latin word “OCCLUSO” defined as the relationship between all the components of the masticatory system in normal function , dysfunction and parafuntion . Development of occlusion is a genetically and environmentally conditioned process which shows a great deal of individual variation.

5. WHAT ARE THE DIFFERENT TYPES OF OCCLUSION NORMAL OCCLUSION: It is class -1 relationship of maxillary and mandibular first molars. PHYSIOLOGIC OCCLUSION: Occlusion that deviates in one (or) more ways from ideal occlusion yet it is well- adapted to that particular environment is esthetic and shows no pathologic manifestations. FUNCTIONAL OCCLUSION: An arrangement of teeth which will provide highest efficiency during excursive movements of mandible which is necessary during function. BALANCED OCCLUSION: An Occlusion in which balance and equal contacts are maintained throughout entire arch during all exursions of mandible .

6. PERIODS OF OCCLUSION DEVELOPMENT PRE- DENTATE PERIOD DECIDUOUS DENTITION PERIOD MIXED DENTITION PERIOD PERMANENT DENTITION PERIOD

7. PRE-DENTATE PERIOD This is the period soon after birth. During this, the neonate has no teeth but the relation of the gumpad is of equal importance. The alveolar process at the time of birth is called the “ Gumpads ”. The maxillae is of “Horse-shoe shaped” and mandible is of “U- shaped”, are pink ,firm and covered with a layer of dense periosteum. They are divided into two parts( Labio -buccal and lingual) by dental groove. The gum pad is further divided into 10 segments by transverse groove, each segment has one developing tooth sac. A very important landmark in gum pad is “ Lateral sulcus” which isthe transverse groove between canine and first molar. This is very helpful in predicting inter-arch relation at a very early stage.

8. The maxillary gum pad is wider and Langer than the mandibular .Thus when they are approximated, there is a complete overjet all around. The only contact that occurs is around the molar region while space exists in anterior region. This is called “ INFANTILE OPEN BITE ”, which is considered normal and helpful during suckling.

9. GUM PADS IMAGE

10. LANDMARKS OF GUM PAD

11. OPEN BITE OF GUMPAD

12. DECIDUOUS DENTION PERIOD The initiation of primary teeth occurs during first six weeks of intra- uterine life and the first primary teeth erupts at the age of 6 months. The individual variations apart , it takes around 21/3 to 31/2 years for all the primary teeth to establish their oooclusion . SPACING IN THE DECIDUOUS DENTITION: It is supposed to be good as spaces in between the teeth can be utilized for adjustment of permanent successors , which are always larger in size compared to the deciduous teeth .

13. CLASSIFICATION OF SPACES PRIMATE SPACES Exists between the maxillary lateral incisors and the canines( present mesial to maxillary deciduous canines) and Mandibular canines and first deciduous molars ( present distal to mandibular canines) These spaces are also called “ANTHROPOID OR SIMIAN SPACES” as they were initially found in ancestral simian species. PHYSIOLOGIC SPACES Present in between all the primary teeth and play an important role in normal development of the permanent dentition. The total space may vary from 0-8mm with the average of 4mm in maxillary arch and 1-7mm with the average of 3mm in mandibular arch.

14. NON- SPACED DENTITION The mesio -distal relation between the distal surfaces of maxillary and mandibular second deciduous molars is called as “ TERMINAL PLANE”.

15. ANTERIOR –TEETH RELATIONSHIP OVERBITE: It is the distance , which the incisal edge of the Maxillary incisors overlaps vertically past the incisal edge of Mandibular incisors . The primary incisors erupt in a deep OVERBITE which I corrected by eruption in the primary teeth around 5 years of age. The average OVERBITE in the primary DENTION is 2mm EDGE TO EDGE BITE: When the incisal edges of the two incisors are in the same plane. This is also called as a “ZERO- OVERBITE”. This is most common due to attrition , Lengthening of ramus and downward forward growth. OVERJET: It is the horizontal distance between labial aspect of maxillary incisor and lingual aspect of mandibular incisors when teeth are in occlusion. It is of 2-4mm

16. PRIMATE SPACE

17. PHYSIOLOGICAL SPACE

18. OVERJET AND OVERBITE

19. CANINE – CANINE REALTIONSHIP

20. MIXED- DENTITION PERIOD The period during which both the primary and permanent teeth are present in the mouth together is known as “MIXED DENTION” . The permanent teeth erupting in place of previous deciduous teeth are the “Successional teeth”, whereas those erupting posterior to the primary teeth are called “Accessional teeth”. This phase begins at around 6years with the eruption of first permanent molars and lasts about 12 years of age.

21. PHASES OF MIXED DENTITION MIXED DENTITION IS DIVIDED INTO THREE PHASES: FIRST TRANSITIONAL PERIOD INTER – TRANSITIONAL PERIOD SECOND TRANSITIONAL PERIOD

22. FIRST TRANSITIONAL PERIOD Characterised by emergence of permanent molars . Exchange of deciduous incisors with permanent incisors . Mandibular molars are the first to erupt at around 6years of age. The position and relation is dependent on the relation of second deciduous molars as they are guided in the dental arch by distal surface of these teeth.

23. EARLY MESIAL SHIFT: The eruptive forces of first permanent molars are strong enough to push deciduous molars forwards.

24. LATE MESIAL SHIFT: Many children lack primate space and have a non –spaced dentition and thus erupting permanent molars are not able to establish class -1 relation even as they erupt . In these cases , the molars establish class -1 relation by drifting mesially and utilising the leeway space.

25. EXCHANGE OF INCISORS: The deciduous incisors are replaced by permanent incisors during this phase. This period of transition is from 6.5-8.5 years. The permanent incisors are larger as compared to its counterparts and these require more space for their alignment. This distance between space available and space acquired is called the “ INCISOR LIABILITY” . It is 1mm for maxillary arch and 5mm for mandibular arch

26. INTER-TRANSITIONAL PERIOD The maxillary and Mandibular arches consists of permanent incisors and permanent molars that sandwich the deciduous canine and molars . This phase lasts for 1-5 years and relatively stable . Oy a few changes in the morphology of deciduous teeth are seen because they undergo attrtion .

27. SECOND TRANSITIONAL PERIOD This period is characterised by a) Emergence of cuspids ,bicuspids and 2 nd permanent molars.. b) Establishment of occlusion. The combined Mesio -Distal width of Permanent canine and premolar is usually less than that of Deciduous canine and Deciduous molars. This extra space is called “ LEEWAY SPACE OF NANCE ”.

28. LEEWAY SPACE OF NANCE

29. UGLY DUCKLING STAGE UGLY DUCKLING STAGE (Broadbent phenomenon)
It is a transient/self-correcting malocclusion seen in the maxillary incisor region between 8-9 years of age.
Erupting permanent canines displace the roots of lateral incisors mesially , resulting in transmission of force on to the roots of central incisors which also get displaced mesially . As resultant distal divergence of crowns of two central incisors causes a midline spacing. This situation has been described by Broadbent as the UGLY DUCKLING STAGE as children tend to look ugly during this phase of development.

30. FIRST TRANSITIONAL PERIOD

31. INTER-TRANSITIONAL PERIOD

32. SECOND TRANSITIONAL PERIOD

33. PERMANENT DENTITION PERIOD The entire permanent Dentition is formed within the jaws after birth except the cusps of 1 st molar which are formed before birth. Some changes that can be seen in permanent dentition are Horizontal OVERBITE decreases. Dental arches become shorter . Vertical overbite decreases upto age of 18 years by 0.5mm Overjet decreases by 0.3mm between 12 to 20 years of age

34. The permanent incisors develop lingual to the deciduous incisors and move labially as they erupt. The premolars develop below the diverging roots of the deciduous molars. At approximately 13 years of age all permanent teeth fully erupt except 3 rd molar

35. PERMANENT DENTITION

36. ANDREW KEYS TO NORMAL OCCLUSION Andrews keys to normal occlusion ■ Key I – Molar relationship MB cusp of the max 1 st molar fall into the mesiobuccal groove of the mandibular 1 st molar and that the distal surface of the DB cusp of the upper first permanent molar should make contact and occlude with mesial surface of the MB cusp of the lower second molar.

37. Key II Crown angulation (Tip) The angulation of the facial axis of every clinical crown should be positive The gingival portion of the long axis of the all crowns must be distal than the incisal portion.

38. Key III Crown inclination In upper incisors, the gingival portion of the crown’s labial surface is lingual to the incisal portion.
In all other crowns, including lower incisors, the gingival portion of the labial or buccal surface is labial or buccal to the incisal or occlusal portion.

39. Key IV Rotations The fourth key to normal occlusion is that the teeth should be free of undesirable rotations.

40. Key V – Tight contacts Contact points should be tight (no spaces).
In absence of abnormalities such as genuine tooth size discrepancies, contact point should be tight.

41. Key VI – Occlusal plane or curve of spee The curve of Spee should have no more than a slight arch. Intercuspation of teeth is best when the plane of occlusion is relatively flat.
A deep curve of spee results in a more contained area for the upper teeth, making normal occlusion impossible.

42. Key VII – Correct tooth size or the bolton’s ratio Bennett and McLaughlin in 1993 gave seventh key to normal occlusion. i.e. The upper and lower tooth size should be correct.

43. ANDREW KEYS OF OCCLUSION

44. SELF-CORRECTING ANOMALIES Anomalies which arise in child’s ,developing dentition during the period of transition from Pre-dentate period to permanent dentate period and corrected on their own without any dental treatment.

45. SELF CORRECTING ANOMALIES

46. REFERENCES TEXT BOOK OF PEDIATRIC DENTISTRY BY NIKHIL MARWAH

47. PRESENTATION DONE BY BATCH –B , BDS 3 RD YEAR 2021-2025 , MNR DENTAL COLLEGE AND HOSPITAL ,SANGAREDDY CH.SAI TEJA B.TEJASWINI ANANYA REDDY THEERDHA RAMYA SAI MAHENDRA VERMA THARUN GOUD YASASWINI REDDY CHAITANYA PRANAVI