Orthodontics Summary

Orthodontics Summary

Primary Dentition (Children) Alignment Issues  Premature loss of primary incisorso Little space change, therefore space maintenance not required o Prosthetic replacement may be necessary due to delayed permanent incisor  Premature loss of primary canineo Causes shift of incisors distally leading to midline deviation and asymmetry o Occurs infrequently o Treatment is described below  Premature loss of primary 1st molaro Space loss doesn’t always occur o Usually though, mesial drift of upper posterior teeth or distal drift of lower incisors o Space maintenance is therefore indicated  Premature loss of primary 2nd molaro 2nd molar is important because it maintains space for 5 and distal root guides 5 into correct position o early loss results in 6 mesial migration within bone o space maintenance is required to guide the eruption of 6 into place Posterior Crossbite  usually due to narrow palatal arch  may be due to sucking habit which constricts maxillary arch into v shape- the molars and occlusal interferences cause functional shift anteriorly and laterally of the mandible  unilateral crossbite is almost always due to symmetrically narrow maxilla and functional shift (NOT true skeletal or dental asymmetry) o hard to get reproducible CR in children o therefore position the midlines together and assess from there o if both the molar and canine widths are reduced- expand arches o NEVER use rapid expansion in preschool child- causes nose changes o if only canine width is reduced- grind deflective contacts Anteroposterior discrepancies  flush terminal plane usually leads to class I relationship in permanent  distal step leads to class II relationship in permanent  mesial step indicates maxillary deficiency or excessive mandibular growth  no treatment in primary unless severe due to risk of relapse Deep overbite  associated with skeletal proportions (i.e. short face, flat mandibular plane)  no treatment in primary due to risk of relapse Anterior Open Bite  usually from thumb sucking habits- proclined upper and Retroclined lowers  anti-habit device, if habit is stopped in primary, teeth will spontaneously correct  if due to skeletal discrepancy (hyperdivergent growth pattern), early treatment is not indicated due to risk of relapse


Early Mixed Dentition (Preadolescent) Crowding and Space issues  Moderate crowding occurs from lack of adequate space leading to deflection of erupting teeth or interferences with eruption (> 3-4mm space discrepancy considered severe)  Irregular incisors, no space discrepancy o Usually due to mild faciolingual displacement/rotation of individual anterior teeth o Up to 2mm of incisal crowding may resolve spontaneously (no treatment required) o Interproximal disking can relieve up to 3-4mm of anterior crowding o Early extensive treatment is not usually indicated as they usually require more comprehensive treatment in permanent dentition anyway  Missing primary teeth with adequate space- maintain the space o Early loss of primary toothlikely drifting of permanent or other primary teeth o Only maintain space if adequate space and all unerupted teeth are present o Band and loop space maintainers where primary 1st molar are lost and >6months before eruption of succedaneous tooth o Partial denture space maintainer where bilateral posterior space maintenance req’d o Distal shoe space maintainer where primary 2nd molar are lost prior to eruption of permanent 1st molar  Usually retained with band not crown  Guide plane must extend into alveolar process, contacting permanent 1st molar 1mm below mesial marginal ridge  Contraindicated- immunocompromised and where infective endocarditis risk exists o Lingual arch space maintainer where multiple primary posterior teeth are lost and permanent incisors have erupted  Usually bands on primary 2nd or permanent 1st molars and arch contacting cingula of incisors  Should be 1-1.5mm from soft tissue  Can also use Nance or Transpalatal  Localised space loss (>3mm)- regain space o Premature extraction of primary can lead to drifting of incisors/molars and space loss o Maxillary space regaining is easier due to anchorage of palatal vault and possibility of head gear o Permanent maxillary first molars can be tipped distally with fixed or removable, bodily movement requires fixed  Removable appliance with Adams clasps, helical finger spring adjacent to tooth to be moved is used when one molar is to be tipped  Headgear or arch wire and excellent anchorage for bodily movement of one/two molars  Space maintainer is always required after space gaining o Mandibular space regaining  Removable lingual arch and loop or fixed appliance with arch wire when unilateral loss of space  Lingual arch can also be used for bilateral loss  NB- lingual arch always has tendency to tip the incisors forward  Lip bumper (tips molars posteriorly and forward movement of incisors) can also be used  Lingual arch can be left in place to maintain space where as lip bumper should eb replaced with band and loop/lingual arch maintainer  Limits for regaining are 3mm from unilateral molar tipping, 4mm total from bilateral molar tipping  Generalised moderate crowding (<4mm) o Early treatment is only considered if major aesthetic concerns since they will probably require comprehensive treatment in early permanent dentition stage anyway o Modest amounts of expansion may be done


o Primary canines can be extracted to allow space, and lingual arch placed to align incisors Severe space problems (5-9mm space discrepancy) can be treated with extraction or expansion o Greater than 10mm discrepancy will always require extraction o Large nose and chin can tolerate more expansion o If expansion leads to incisor protrusion- need to extract (i.e. pt not tolerating expansion)  Serial extraction o Criteria- must be Class I skeletal and Class I malocclusion, greater than 10mm crowding, minimal overbite/overjet (may increase post treatment), no missing teeth o Extract B’s as 1’s erupt o Extract C’s as 2’s erupt o Extract D’s when ½- 2/3 root development on 4 o Extract 4 before eruption of 3’s o After SE, incisors drift lingually and molars drift mesial closing up 2-3mm per quadrant o Patient usually required further ortho treatment for alignment Anterior Dental Spacing  Maxillary Midline diastemas o Usually ugly duckling stage- tend to resolve spontaneously when canine erupt o With large diastemas, look for midline supernumerary or soft tissue/intrabony lesion, missing lateral incisors, digit sucking habits o Central incisor tipping for diastemas less than 2mm  Protrusion and spacing o Treatment in early mixed stage is only indicated when maxillary incisors protrude with spaces between them and are aesthetically/traumatically a concern o Usually caused by thumbsucking habits or true skeletal discrepancies o Removable/fixed appliance to tip incisors palatally if adequate vertical and arch space o If overbite problem exist, this must be addressed before retraction o Fixed appliance recommended where significant retraction required o Severe protrusion- premolar extraction and incisor retraction or defer until permanent dentition Eruption Problems  Over retained primary teeth o Permanent tooth should replace primary when ¾ of permanent root is formed o Caused by displacement of permanent tooth bud or early loss of primary tooth, leading to layer of bone formation over unerupted tooth- DELAYING permanent tooth eruption o Over retained maxillary molars usually have buccal/palatal root intact, over retained mandibular molars usually have mesial/distal root intact o Child may wiggle tooth out if permanent crown is visible and primary tooth can be moved 1mm in faciolingual direction o Extraction of retained primary tooth otherwise  Ankylosed Primary teeth o Potential alignment problem for primary teeth o Usually resorb, but may retain and delay eruption of permanent tooth or deflect its path o Ankylosed tooth maintained until interference with eruption/drifting occurs, then extraction and space maintainer placed  Ectopic Lateral incisors o Ectopic= permanent tooth cause resorption of primary tooth or any tooth other than the one it is supposed to replace o Space analysis, assessment of anterioposterior incisor position, facial profile are used to decided where space maintenance, regaining or complex treatment required o When one primary canine lost Remove contralateral canine  Maintain position of lateral incisor on side of canine loss using lingual arch o When both primary canines are lost Active lingual arch for expansion  Passive lingual arch for maintenance  No treatment 


Ectopic maxillary first molars o Monitor when only small amounts of resorption observed (can spontaneously correct) o If blockage of eruption >6months or resorption continues, treatment required o 20 mil brass wire looped, tightened between contact of primary 2nd molar and permanent molar if little/none of permanent 1st molar is visible (wire tightened every 2 wks) o Steel spring clip separator is only small amount of resorption exist o Fixed appliance with band on 2nd primary molar, Transpalatal arch and cantilever arm extending distally behind unerupted permanent molar in more severe cases o Extraction may also be required in some severe cases  Ectopic Maxillary canines o Can lead to impaction of canine and/or resorption of permanent lateral incisor roots o OPG or PA required for 10 year old child with no palpable facial canine bulge and immobile primary canine o Extract primary canine when mesial inclination of permanent canine but no incisor root resorption o Extract primary canine, surgically expose permanent canine and use orthodontic force to bring into correct position when there is resorption of permanent incisor root Posterior Crossbite  Heavy force and rapid expansion not indicated in primary/early mixed dentitionnose distortion  Usually due to bilateral constriction of maxillary arch and mandibular shift  Can be due to intra-arch or jaw asymmetry, or habits causing narrowing or arch Crossbite with mandibular shift should be treated as soon as diagnosed to prevent soft tissue growth modification, dental compensation and abrasion  Equilibriation to eliminate mandibular shift o Sometimes crossbite is solely due to primary canine interference in which they can be easily eliminated  Expansion of maxillary arch o Removable appliances o W arch or quad helix  Repositioning of individual teeth Anterior Crossbite  If problem is dental and space is available, should be corrected when diagnosed  Most likely tho, it is caused by lack of space in which total space should be considered in TP as well as crossbite  If developing crossbite discovered before complete eruption and overbite establishmento Extract adjacent primary teeth to allow space  If developing crossbite is diagnosed after eruption and overbite establishment-\ o Removable appliance with finger springs to allow facial movement of incisors o Offending teeth should be overcorrected and retained until overbite is adequate to retain o Fixed appliances can also be used when compliance is an issue Anterior Open bite  major cause once again is HABITstop habit with devices etc o crib has a high success rate, retain crib for 3-6months after cessation of habit o possibly maxillary expansion, headgear and bite blocks  True vertical excess o Control vertical growth of mandible to allow upward/forward rotation o Needs active retention for numerous years to avoid relapse o High pull headgear to molars- inhibit max molar eruption o High pull headgear to maxillary splint- directs force to entire maxillary dentition- very long tmt period so compliance is essential o Functional appliance with bite blocks- inhibit eruption of posterior teeth and vertical maxillary growth o High pull headgear to functional appliance with bite blocks- most effect for severe casesanterior repositioning of mandible and controls eruption Deep bite (skeletal vertical deficiency) 

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usually have some degree of mandibular deficiency and Class II div II malocclusion, reduced facial height, everted, prominent lips, flat mandibular plane  aim to increase eruption of posterior teeth, stimulate downward rotation of mandible without decreasing chin prominence  Frankel functional to allow posterior eruption  Bionator to allow posterior eruption and block anterior eruption  Cervical headgear can be used to induce eruption of upper molars (functionals are preferred because short faced Class II is best treated with eruption of lower molars) Maxillary Deficiency (Transverse)  narrow arch, usually produces posterior crossbite  rapid expander, slow expansion plate or Quad helix  at this age, less force is required, but lots of retention will be needed and compliance is essential  preferably before 9-10 yrs, 3 months retention required Maxillary Deficiency (Anteroposterior and vertical)  both can contribute to Class III malocclusion  preferred treatment is move maxilla down and forward by manipulating posterior and superior sutures  easiest at young age but can be done into early adolescence  Reverse pull head gear (facebow attached to molars and anchored at forehead/chin)  Functionals (Class III frankel) stretches periosteum to stimulate forward growth of maxilla- mostly DENTAL changes not skeletal Mandibular deficiency (Class II)  Headgear to treat maxillary excess o Tips molars distally but doesn’t effect other teeth  Functional appliances o Place a distal force on maxillary incisors tipping them distally o Exert protrusive effect on mandibular dentition o Bionator, Frankel, Herbst, Fixed twin block (fixed exert greater dental effect due to constant force) o Contraindicated if there is mandibular dental protrusion o Biteplates can be added to level excessive curve of Spee o If there is hyperdivergent tendencies, posterior eruption should be prevented to prevent expression of growth vertically  Treatment procedure for functionals o Patient must be able to posture mandible forward 4-6mm o If this is prevented by palatal maxillary incisors or crowded incisors, this must be corrected first with fixed/removable appliances plus 6 months retention o Take wax bite with 4-6mm mandibular protrusion and 3-5mm open bite Maxillary excess (Class II)  maxillary grows downward, mandible grows downward and backward, therefore mandibular growth is not being expressed anteriorlyClass II malocclusion  headgear to reduce maxillary growth and allow mandible to catch up o applied to 6’s by facebow with neck strap/head cap for anchorage (10-12hrs a day) o forces need to be 350-450g per side (great enough to cause skeletal as well as dental changes)  functionals may also be helpful in cases of excess VD Mandibular excess (Class III)  difficult to treat, truly inhibiting growth is impossible, most will be surgery cases  Facemask protraction headgear and Class III Frankel Asymmetry  Congenital abnormalities- hemifacial microsomia, Hemimandibular hypertrophy  Trauma- fractured condyle o Functional appliance during post injury period to minimise growth restriction o i.e. Bionator advancing the mandible to near edge to edge occlusion so mandible is forced to translate and remodelling can occur 


o

if the fracture goes on undetected, and asymmetry develops, use hybrid functional appliance, possible surgery

Early Permanent Dentition (Adolescent) Alignment Problems  Crowding and Protrusion o Perform space analysis o Simple appliances are not as effective (and expansion will make protrusion worse) o Extraction and closing spaces is indicated  Mild Lower crowding o Lingual arch to hold leeway space o Lip bumper to hold leeway space and tip molars back o Transverse/anterior flaring o Extraction and fixed appliances  Mild upper crowding o Lateral/anterior expansion (flaring) o Molar distalisation with headgear o Extraction and fixed appliances  Tooth size discrepancies o Bolton Analysis to determine if discrepancy is localised or generalised o Less than 1.5mm discrepancy is insignificant o If greater than 1.5mm, then can alter incisal inclination, interproximal stripping, composite build ups, or accept your mutant child Transverse Problems  usually from narrow maxilla  rapid/slow expansion plate, sutures are more interdigitated, but some expansion can occur as late as 15-18yrs (heavier forces required)  3 months retention required Anteroposterior Problems  Class II and Class III o Growth modification before adolescent growth spurt o Camouflage o Surgery Vertical Problems  Anterior Open bite o Usually have increased facial height and steep mandibular plane, excessive maxillary vertical growth, forward rotation of mandible, excessive eruption of posterior teeth o If due to habit, even if habit is stopped at this stage there is no self correction  Deep Overbite o Resulting from upward/forward mandibular rotation, excessive eruption of lower incisors Impacted teeth/failed eruption o Surgical exposure of impacted teeth but there is risk of ankylosis o Generalised eruption failure from mechanical interferences (can be removed) or failure of eruption mechanism (these teeth don’t respond to ortho forces) Traumatic displacement/Ankylosis  trauma can lead to displacement of tooth in bone, if any part of PDL is obliterated, bone fused to cementumankylosis  Displacement of permanent tooth bud can also lead to dilaceration 

Non-Growing Patients (Adult) Skeletal Class II  Camouflage o Run Class II elastics to fixed appliances, tends to produce bimaxillary dentoalveolar protrusion and full lips and retrusive looking chin


Upper premolar extraction, retract upper teeth back (usually retract 1/3 distance of extraction space and the molars move the rest of the distance forward). o Head gear may be used for anchorage and prevent molars moving forward o Could also extract premolars in the lower arch to move lower molars forward while retracting the upper molars  Surgery- post puberty Class III  Camouflage- doesn’t work very well at all o Procline maxillary and retrocline mandibular- potential for unaesthetic result and mobility from imbalance of occlusal forces o Extraction of lower teeth followed by retraction- prominence of lower lip decreases, pointy unaesthetic chin results  Surgery- when facial growth is complete Vertical Excess  Camouflage- doesn’t’ work well either o Elastics running vertically to close the open bite would lead to increased unaesthetic tooth display  Surgery- when facial growth is complete o

Orthodontics Summary

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