Ortho Pedo

BONE FORMATION / OSSIFICATION :- INTRAMEMBRANEOUS- within membrane  Ossification takes place in the membranes of connective tissue.  Cells in the membrane differentiate into osteoblasts,  A collagen matrix is formed, which undergoes ossification  So basically, these bone is formed from collagen matrix.  Mostly flat Bones: maxilla, majority of mandible & cranial vault* ENDOCHONDRAL – within cartilage  Bone formation takes place From within a hyaline cartilage  Cartilage cells are replaced by bone cells,ie. osteocytes replace chondrocytes.  short and long bones are formed this way  ethmoid, sphenoid, occipital (synchondrosis of bones of cranial base*)  Some part of mandible (condylar head region)  MANDIBLE BONE FORMATION IS BY BOTH endochondral + intramembraneous

BONE GROWTH  Don’t confuse bone growth with bone formation above  Growth of bone is by apposition — layer by layer deposition  Whereas cartilage growth is by two ways one is appositional and other is interstitial method, which is how mandibular condyle grows.  Mandible growth starts at 6th wk of IUL & completes at 12-13 years  Individual — 1st bone to ossify — clavicle— entire body  1st bone to ossify in head — mandible -2nd bone to ossify overall  Maxilla growth starts after mandible but completes earlier than mandible Start (6th wk of IUL)----- (MANDIBLE) --------------finish (12-13 years) -----------------START -------------------FINISH------------------------- -------------------------------MAXILLA----------------------------------- MANDIBLE  Primary cartilage of mandible — Meckel’s cartilage but it does not individually induce or contribute to mandibles growth  Secondary cartilage — condylar cartilage  This cartilage contributes to its growth*  Direction of growth — anterior and inferiorly  Direction of apposition @ condylar — posteriorly and superiorly  V shape principle- is shown by the mandibular growth MAXILLA  Formed entirely by intramembranous ossification  Growth is by apposition at sutures and surface remodelling  Direction of growth/migration – downward and forward  Direction of apposition – downward at alveolar area and at tuberosity area  MAXILLA IN A NUTSHELL: o Increases in height by continuous growth at alveolar bone o Increases in width by mid-palatine suture o Increases in depth by apposition at anterior region and tuberosity

SCAMMON’S GROWTH CURVE — GROWTH SPURTS 4 GROWTH SPURTS 1. JUST BEFORE OR AT BIRTH - Most rapid growth in human occur during pre-natal period 2. 1 YEAR AFTER BIRTH 3. PRE-PUBERTAL [GIRLS 5-6YEARS., BOYS 6-8 YEARS] 4. PUBERTY [GIRLS 10-12, BOYS 12-14] Mandibular growth coincides with 4th growth sprout ie; pubertal growth A. Neural — Brain a. At birth 50% b. At 4-6 years — 95% c. So below this age, ie around 3 yrs child will not be able to differentiate colours, tell his name and so. d. Complete at 15 years age — 100% B. Genital a. Begins at 12 years b. Complete at 18 years C. Lymphoid / immunity a. At peak — 200% — 12 years b. Complete — 100% — 18 years ∴ immunity is highest in children

BONE JOINTS  SYNOSTOSIS Bone formed b/w two bone junction  SYNCHONDROSIS Cartilage formed at the junction of two bones Eg. Spheno-occipital synchondrosis  SYNDESMOSIS Ligament formed at the junction of two bones Eg: stylohyoid PAIRED & UNPAIRED BONES Total no. of bones in skull :-  At birth — 45 bones  Later — 22 bones * Unpaired bones in skull :- A. Frontal [FACE OF SUHAIRA EPPO VIDARUM MACHA?] B. Occipital C. Sphenoid D. Ethmoid E. Vomer F. mandible REST ALL ARE PAIRED

DEVELOPMENT OF OCCLUSION  GUM PADS  0-6 months of age  Anterior open bite  So such complaint of open mouth by mother at this age o Rx — self correcting anomaly ! (SCA)  NATAL TOOTH – tooth present at birth  NEONATAL TOOTH — tooth formed within 15 – 30 days.  Most common — mandibular (anterior) central incisor  Syndrome — Rege fede syndrome  Inability to suck milk —  Nutritional deficiency  Lower part of tongue irritation.  ALVEOLAR RIDGE Transverse grooves — it divides the gum pad into 10 segments for future eruption of the teeth. CALCIFICATION DATES  1st calcification seen at 14 weeks of IUL, max sinus develops  12th week – mandible  6-10weeks- palate  4-6 weeks- lip  In pedo root formation completes 1year after eruption  As a general rule, o four teeth erupt for every six months of life, o mandibular teeth erupt before maxillary teeth, o teeth erupt sooner in females than males. o During primary dentition, the tooth buds of permanent teeth develop below the primary teeth, close to the palate or tongue. Tooth bud is always — lingual / palatal and inferiorly placed.

PEDO TEETH  Smallest — mandibular L1  First erupting — mandibular C1  Largest tooth — mandibular 2nd M PERMANENT TEETH  Smallest — mandibular CI  Largest — maxillary 1st M  First erupting — mandibular CI SPACES  In primary teeth — physiologic space  It is self correcting anomaly  Midline Diastema  Maxillary 1.7mm — mesial to C  Mandibular 1.5mm — distal to C  They are known as Primate space or Anthropoid space or Simmian space. SELF CORRECTING ANOMALIES o Anterior deep bite — 6 months age anomaly o (SCA) — Self correcting as posterior teeth erupts o (self – correcting anomaly)

DECIDUOUS OCCLUSIONS :- PRIMARY 2ND MOLARS FLUSH TERMINAL PLANE (SCA)  Most Commonly seen occlusion*  Straight line occlusion EDGE TO EDGE OR END ON Crowded , Improper jaw growth CLASS I OCCLUSION Mesiobuccal cusp of maxillary 1st M in the mandibular mesiobuccal groove Usually a flush terminal will end up in class 1 itself Self – correcting anomaly MESIAL STEP OCCLUSION  Ideal Occlusion CLASS III – When space is utilized CLASS I – If space not utilized DISTAL STEP OCCLUSION CLASS I – If space is utilized CLASS II- if space is not utilized  MIXED DENTITION :- o Started #6 eruption of mandibular 1st Molars o Finishes #3 eruption of maxillary C or #5 eruption of mandibular 2nd PM

PERMANENT SEQUENCE OF ERUPTION MAXILLA 6 1 2 4 5 3 7 MANDIBLE 6 1 2 3 4 5 7  1st permanent tooth — mandibular 1st M  1st successor tooth — mandibular CI  Last successor tooth — max C *** OR mandibular 2nd PM

STAGES OF MIXED DENTITION :- FIRST TRANSITION STAGE [ 6 – 8 ]  Erupting — C1, L1, 1st Molars  Anomaly — anterior open bite o — retrognathic mandible (12-14) o — ∴ transient class 2  At 8.5yrs old, there will be equal no of primary and permanent teeth in the mouth,  Centrals, laterals and 1st molars-permanent  Canines, 1st molar, 2nd molar-primary  Incisal Liability o Maxilla — 7mm o Mandible — 5mm  ∴ avg I L = 6 mm  How is I L Obtained: o utilising the physiologic spaces o proclination of anterior o increase in the inter – canine width

INTER – TRANSITION STAGE [ 9 – 11 ]  Anomaly — ugly duckiling stage (9 – 11 years) *** v.imp o — midline diastema (SCA)  Erupting — canines  Distoangular axial inclination of maxillary incisors!  Rx – wait till canines erupt completely – 11 years  After that — ortho Rx. SECOND TRANSITION STAGE  Erupting — C, 1st PM and 2nd PM  3, 4, 5, 7  Anomaly — anterior deep bite  LEEWAY SPACE — primary Molars > permanent Molars  it is the space deference between the combined mesiodistal width of the C,D & E teeth and that of their successors ( 3 ,4 and 5 ) which is  1.9 mm in maxilla & 3.4 mm in mandible.  — This space is utilized for primary occlusion to permanent occlusion  — late mesial shift o Maxilla — 0.9 mm o Mandible — 1.7 mm

NON – SELF CORRECTING ANOMALIES :- SKELETAL 1. Skeletal Class III 2. Skeletal class II MIDLINE DIASTEMA * after 11 years or C eruption a] Hgh frenal attachment  Blanch test — to detect high frenum attachement  Frenectomy  Wait for eruption of remaining teeth  Ortho b] unerupted mesiodense  Rx o Occlusal radiograph o If before C eruption — extraction of mesiodens might close the gap as C erupts completely o If after C eruption — extraction of mesiodens + fixed ortho

CROSSBITE a. 1st seen at 7 – 8 years b. ∴ 1st ortho visits @ 7 – 8 years ** c. 1st dental visit @ 6 months ** d. 𝑎𝑛𝑦 𝑚𝑎𝑙𝑜𝑐𝑐𝑙𝑢𝑠𝑖𝑜𝑛 — due to early lossof primary teeth e. 𝑎𝑛𝑡𝑒𝑟𝑖𝑜𝑟 𝑐𝑟𝑜𝑠𝑠𝑏𝑖𝑡𝑒 — retained primary teeth ANTERIOR CROSSBITE DEVELOPING Rx – icecream stick pushes DEVELOPED Rx – orthodontic 1) Catalans appliance a. 6 weeks b. Lower teeth c. 45° angulation d. If Catalans appliance used more than 6 weeks e. Then — separation of occlusion in posterior 2) Z – Spring with posterior bite plane a. For developed crossbite

2) Z – Spring with posterior bite plane a. For developed crossbite POSTERIOR CROSSBITE  Reasons — narrow maxillary jaw  Rx plan o Expansion of maxillary arch o Maxillary expansion device o At or above 7 years of age o Max suture growth ends at 15 years o Both unilateral and bilateral posterior crossbite  Function of expansion device —bilateral expansion  Effect seen when midline diastema appears  This diastema closes as a result of relapse  No Rx required for midline diastema UNILATERAL CROSSBITE 1. LAERTOGNATHY / TRUE CROSSBITE The center of the mandible and the facial midline does not coincide in both rest and in occlusion 2. LATEROCCLUSION The center of the mandible and the facial midline coincide in rest position butttt in occlusion the

MAXILLARY EXPANSION DEVICE RAPID MAXILLARY EXPANSION (RME) a) Per day 0.5 mm* b) Key turn/ activation :- - ¼ turn twice daily* or - Quarter turn twice daily or, - 0.25 mm twice daily c) Eg: Hyrax - Ratio =𝑑𝑒𝑛𝑡𝑎𝑙/𝑏𝑜𝑛𝑒= 1: 1 - The ratio of dental & skeletal expansion obtained after RME is 1 : 1 SLOW MAXILLARY EXPANSION (SME) a) 0.5 mm per week* b) eg: quad helix c) unwind the coil(no key system)

HABITS THUMB/DIGIT SUCKING, PACIFIER  Normal upto 3 years according to — Psychosexual theory — Learning theory — Oral drive theory — Routine reflex theory — These theories support that up to 3 years its normal  Side effects if continued after 3 years - Increased overjet – owing to Maxillary anterior teeth proclination & Retruded and crowded mandibular incisors - Posterior crossbite (due to action of buccinator muscle During the sucking action – buccinator mechanism) - Anterior open bite, flaring max incisors - Anteriorly displaced maxilla, Retruded mandible - ie. Class II occlusion - Dish pan thumb - Deep palatal vault  Treatment phase - Counselling phase (all age group) - If dental damage not happened, Pychological treatment to withdraw from habit - But- if already dental dame caused- Definitive management Definitive management 1. 4 – 5 years age —1st phase : reward therapy 2. 5-6 years age and above : 2nd phase : reminder therapy  Tongue crib - Fixed - Removable  Blue grass appliance(also given in tongue thrusting) - Fixed appliance with six sided plastic roller on the anterior surface of palate region. 3. 3rd phase : corrective therapy  Quad helix — habit breaker + arch expansion (Dip finger — pepper solvent, asefoitida solvent - it is an adjacent therapy)

TONGUE THRUSTING  Proclination of anterior both maxillary and mandibular  Rx - Tongue crib / blue grass appliance – must be used as soon as the habit is noticed - Atleast 6 months (Rx) + 3 months (retention purpose) - Total about 9 – 10 months ‘Duration of habit force — determines the degree of malocclusion’ – not the frequency MOUTH BREATHING Reasons: - Obstructive problem Eg: adenoids Rx: refer to ENT surgeon for removal of adenoids - Habitual problem Patients who show this habit even after surgical correction, this is habitual now, ie despite no obstruction now, they are breathing due to th habit they developed before. Rx : oral screen / mouth screen (only in cases no obstructive causes or H/O removal of cause) Clinical features  Anterior proclination  Incompetent lip seal LEPTOPROSOPIC  Long face syndrome  They have posterior cross bite  Said to have a classic adenoid face  Poor lip seal Tests used for investigation of mouth breathing  Mirror test * * *  Butterfly test  Waterbath test

MODEL ANALYSIS  Why – to determine the arch length and tooth material discrepancy o If the discrepancy less than 2.5 mm - proximal stripping prior to ortho o If the discrepancy more than 2.5mm – 5 mm - extraction of 2nd PM, usually after starting ortho o If the discrepancy more than 5 mm – 10 mm - extraction of 1st PM  Proximal stripping remove only 50% enamel, otherwise there will be severe sensitivity.  Normal occlusion — Andrew’s six keys  7th key added — Bolton ratio = 91.3%

MIXED DENTITION ANALYSIS  WHY — to predict the crowding of maxillary or mandibular arch  Determines the space available vs the space required  It is the best investigatory method for serial extarcation  HOW (Moyer’s analysis) —𝒔𝒖𝒎 𝒐𝒇 𝒎𝒂𝒏𝒅𝒊𝒃𝒖𝒍𝒂𝒓 𝒊𝒏𝒄𝒊𝒐𝒓 𝒘𝒊𝒅𝒕𝒉 (𝒄𝒊+𝒍𝒊) / 𝟐  The size of unerupted permanent canines and PMs are predicted from the knowledge of the size of M-D width of mand incisors.  Mxillary incisors are never measeared coz of high chance of variability. Mandibular is taken even to predict maxillary space discrepancy.  Best analysis done = Stanley kaber analysis*  Tooth cause crowding in lower anterior region if early extracted: Primary mandibular first molar lower ie. D*  Most teeth responsible for crowding is: Lower E & upper D SERIAL EXTRACTION:- C D 4 — order * if discrepancy > 10mm  Preferred — Dewel procedure  Done at 8-9 years only if there is crowding!  Anything before that extract ad give space maintainer.  Go for double extraction if age 8-9 and crowding not present  Advantages : o Interceptive orthodontics Easy ortho movement in future due to breakage of transseptal fibres — no relapse o Helps eruption of permanent canine ?

SPACE MAINTAINERS:-  Function — to maintain space  Space closure is least likely to occur in primary maxillary 2nd molar  Anterior SM function — o To maintain phonetics o Aesthetics o Space maintenance  Fixed SP is better  Removable space maintainer used when SM required at multiple location Eg: RPD