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Growth and development of the nasomaxillary complex /certified fixed orthodontic courses by Indian dental academy
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Growth and development of the nasomaxillary complex /certified fixed orthodontic courses by Indian dental academy




The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call



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Growth and development of the nasomaxillary complex /certified fixed orthodontic courses by Indian dental academy Growth and development of the nasomaxillary complex /certified fixed orthodontic courses by Indian dental academy Presentation Transcript

  • Growth and development of the Nasomaxillary Complex www.indiandentalacademy.com
  • INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  • Contents            Introduction Embryology & Prenatal growth Natal growth Post natal growth Concepts of growth Developmental sequence Normal variation and malocclusion Nasopharyngeal airway Evolutionary changes Anomalies Conclusion www.indiandentalacademy.com
  •  In the closest union there is still some separate existence of component parts; in the most complete separation there still is a reminiscence of union. Samuel Butler www.indiandentalacademy.com
  • Pharyngeal arches www.indiandentalacademy.com
  • Early orofacial development  The development of head depends on    Prosencephalic centre Rhombencephalic centre Prosencephalic centre -migrates from the primitive streak  Induces    Visual and inner ear apparatus Upper 1/3 of face Caudal Rhombencephalic centre  Induces middle and lower 1/3 of face and middle and ext ears. www.indiandentalacademy.com
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  • Formation of the Human Face  1st characterized by an invagination in the ectoderm below the forebrain. As it deepens,it forms an outline of the oral cavity.  Prechordal Plate   demarcates the site of the stomodeum( 14th day) endodermal thickening contributes tooropharyngeal membrane. Ectoderm – forms mucosa of mouth.  Endoderm – forms mucosa of pharynx.  Mesoderm – does not intervene.  www.indiandentalacademy.com
  •  Face develops from 5 prominences surrounding the stomodeum     Frontonasal Two maxillary processes Two mandibular processes 1st Arch Derivatives All prominences and arches arise from neural crest cells-caudal stream www.indiandentalacademy.com
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  • Frontonasal prominence 4th week iu  Develops from Cranial stream of neural crest cells proliferate downwards to form FN process.  It surrounds the developing forebrain  Nasal placodes arises inferolaterally www.indiandentalacademy.com
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  • 5th week IU  Face crowded between forebrain and heart which begins to pulsate & affects development of face because of importance of blood supply.  The face grows downwards and forwards.  Face is about 11/2 mm wide. www.indiandentalacademy.com
  • Fusion  Fusion of MNP;LNP and MP –  Fusion – MNP and MP provides –    Continuity of upper jaw and lip. Separation of nasal pits from stomodeum. Fusion – MNP and MNP – at midline     Median tuberculum Philtrum Tip of nose Primary palate – gives rise to premaxilla. www.indiandentalacademy.com
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  • 7th week IU  Shift of blood supply face from ICA to ECA because of normal atrophy of stapedial artery.  Potential for defects upper lip and palate. www.indiandentalacademy.com
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  • Development of Nose  derives contribution from     FN Prominence -Bridge. MNP’s – Median Ridge and tip LNP’s – Alae Cartilage Nasal Capsule – Septum and nasal conchae. Superficial alar field – external alar cartilage. www.indiandentalacademy.com
  •  5th week iu   2 raised areas appear above future mouth. centers of these raised areas become depressions as tissues around them start growing Nasal pits become nostrils-fusion of MN, MP and LNP .  Distance between pits does not increase but pits increase in height and length. www.indiandentalacademy.com
  •  It is separated from stomodeum by oronasal membrane which disintegrate to form primary chonae (primitive posterior nares  Definite choane of adult –form by fusion of secondary palatal shelves. www.indiandentalacademy.com
  •  Within FNP –mesenchymal condensation forms the precartilaginous nasal capsule    Mesoethmoid-prologue to nasal septum Ectethmoid-ethmoid and nasal alar cartilage The primary nasal septum is broad – between primary choane but builds up in a rostrocaudal direction as the palatal shelves fuse. www.indiandentalacademy.com
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  • NASOLACRIMAL DUCT  Between LNP and MP-rods of epithelial cells sink into adjacent mesenchyme.Rods extend from conjunctival sac of developing eyelid to external nares.They later canalize to form nasolacrimal sacs and ducts and become completely patent after birth www.indiandentalacademy.com
  • Upper Lip  Forms in 3 steps 1-Contact between MP and MNP together forming lamina nasal fin.  2- fusion into a single sheet.  3-Degeneration of this sheet resulting in connective tissue penetration through it.  www.indiandentalacademy.com
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  • Cranial Base  The neurocranium can be divided into   Calvaria-from desmocranium Cranial base-from chondrocranium www.indiandentalacademy.com
  • Chondrocranium  4th week iu  Occipital sclerotomal mesenchyme concentrates around notochord and extends cephalically forming floor for the brain.  Conversion of the mesenchyme to cartilage constituents the beginning of chondrocranium www.indiandentalacademy.com
  •  The chondrification centers are Parachordal cartilages-around notochord  Sclerotomal cartilages-occipital bone parts  2 Hypophyseal cartilages-fuse to form basisphenoid cartilage  2 presphenoid cartilages- body of sphenoid   Orbitosphenoid and Alisphenoid- wings of sphenoid Mesoethmoid cartilage-fused presphenoid cartilages www.indiandentalacademy.com
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  •  Capsules around nasal and otic sense organs ossify and fuse to the cartilages of cranial base    nasal capsule- chondrifies in 2nd month to form nasal septum which ossifies into ethmoid and vomer otic capsules chondrify; fuse with parachordal cartilages to ossify as mastoid and petrous part of temporal bone All chondrification centres fuse to into a single irregularwww.indiandentalacademy.com plate porous basal
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  •  Chondrocranial ossification  110 ossification centers in human  45 bones in neonatal skull  22 bones in adult  Centres of ossification commence with the alisphenoids in 8 week IU  Unossified chondrocranial remanants persist at birth as     alae and septum – nose spheno-occipital and spheno- petrous junction apex – petrous bone between separate parts occipital bone www.indiandentalacademy.com
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  • CRANIAL BASE ANGULATION  prechordal and chordal parts meet at an angle at the hypophyseal fossa       Lower angle – from nasion to sella to basion 4 week - 150° (cartilage stage) 7-8 week - 130° 10 weeks – 115 - 120° (pre ossification Stage) 10-20 weeks–125–130° maintained postnatally. Flattening – is caused by rapid growth of brain during fetal period as chondrocranium retains its fetal flexure www.indiandentalacademy.com
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  • CRANIAL BASE FORAMEN  I – determines perforations of cribriform plate  II and opthalmic artery -orbitosphenoid cartilage fuses with basal plate-optic foramen.  III, IV, V, VI and ophthalmic veins-orbitosphenoid and alisphenoid – superior orbital fissure  Junction between alisphenoid and presphenoid cartilages are interrupted by V1 - Formen rotundum V2-Foramen ovale www.indiandentalacademy.com Middle meningeal artery-Formen spinosum
  •  cartilage between alisphenoid and otic capsule –Foramen Lacerum  VII and VIII - otic capsule ensures- internal acoustic meatus  IX,X,XI and IJV - otic capsule and parchordal cartilage- Jugular foramen  XII-occipital selerotomes – anterior condylar canal  Spinal cord – f. magnum www.indiandentalacademy.com
  • FACIAL SKELETON   Upper 1/3 of face –grows rapidly Middle and lower 1/3 grow slowly and over a prolonged period www.indiandentalacademy.com
  •  Facial bones develop intramembranously  Interaction between neural crest ectomesenchyme and overlying ectodermal epithelium is essential for differentiation of facial bones www.indiandentalacademy.com
  •  Frontonasal prominence- 8th week – nasal and lacrimal bone  Maxillary Prominence – 8th week      medial pterygoid plate vomer Greater wing of sphenoid Lateral pterygoid plate Palatine www.indiandentalacademy.com
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  • Pre maxilla  Originates in 7th week on the external surface of nasal capsule. It extends upwards and backwards where it joins the maxilla proper at 8th week www.indiandentalacademy.com
  • Maxilla    Acc to Jacobson it develops from a condensation of embryonic mesenchyme within the maxillary process of the mandibular arch 1° ossification centre-7th wk iu- at termination of infra orbital nerve just above the canine tooth dental lamina. 2° ossification centers – zygomatic orbitonasal nasopalatine www.indiandentalacademy.com intermaxillary
  •  Points of attachment PM fissure – sphenoid and maxillary bone  Pterygopalatine fossa – sphenoid and palatine  ZT suture – zygomatic bone and temporal  ZF suture -frontal and zygomatic bone  MF suture-frontal and maxillary  FN suture – frontal and nasal www.indiandentalacademy.com
  •  Growth of maxilla depends upon several functional matrices that act on different areas and thus allowing for its subdivision into skeletal units.  a) Basal body  b) Orbital unit  c) Nasal unit  d) Alveolar unit  e) Pneumatic unit www.indiandentalacademy.com
  •  The complexity of action of forces results in different effects on different sutures  TZ suture - A-P horizontal growth - brain and s-o synchondrosis.  F-M, F-Z, F-N, E-M,F-E suture - vertical growth eyeball and nasal septum expansion  N-M suture-A-P growth-nasal septum www.indiandentalacademy.com
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  • Eyes  Its growth provides an expanding force separating neural and facial skeletons at FM and FZ sutures therefore increasing the height.  They migrate medially due to expansion of frontal and temporal lobes of brain www.indiandentalacademy.com
  • Eye balls  Grow rapidly following neural pattern of growth and contributing to rapid widening of the face.  half of postnatal growth- 2 years adult dimensions- 7 years.  www.indiandentalacademy.com
  • Nasal Cavity and Septum  A septomaxillary ligament arises from nasal septum and inserts into Anterior nasal spine. It transmits septal growth ‘pull’ on the maxilla.  Facial growth is directed downwards and forwards by the septal cartilage www.indiandentalacademy.com
  • Palate  Derived from   two lateral max palatal shelves primary palate of F-N prominence  initially vertically oriented  8th week iu transformation from vertical to horizontal  considerable sex difference in timing. Earlier in male than female embryos. www.indiandentalacademy.com
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  •  Factors influencing change of orientation  Biochemical transformations in physical consistency of connective tissue matrices.  Variation in vasculature and blood flow  Sudden increase in tissue turgor.  Rapid mitotic activity  Intrinsic shelf force  Muscular movements  Withdrawl of face from heart prominence www.indiandentalacademy.com
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  •  Fusion occurs initially - anteriorly in hard palate, combination of degenerating epithelial cells, and a surface coat accumulation of glycoproteins and desmosomes facilitates epithelial adherence www.indiandentalacademy.com
  •  The fusion initially produces a flat, unarched roof.  Junction of components -incisive papilla. Line of fusion- mid Palatine suture.   This fusion seam is minimized in soft palate by invasion of extra territorial mesenchyme. www.indiandentalacademy.com
  • Cross-sectional view of palate at various ages www.indiandentalacademy.com
  •  Ossification - 8th week iu  Anteriorly-primary ossification centre of maxilla Posteriorly- primary ossification centre of palatine bones.   Mid palatal suture     10 1/2 weeks-fibrous layer in the midline. infancy Y shape in coronal section childhood - T shape adolescence - Interdigitated www.indiandentalacademy.com
  • Paranasal sinuses  The 4 sinuses Maxillary ,Ethmoidal ,Sphenoidal ,Frontal- 3rd month iu as outpouchings of mucous membrane of nasal meatus and spheno-ethmoidal recess.  primary pneumatisation-growth of mucous membrane sacs into the bone secondary pneumatisation-sinuses enlarge into bones  www.indiandentalacademy.com
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  • AT BIRTH  Maxilla at birth -contains deciduous teeth in various stages of completion and buds of permanent teeth.  Alveolar process is not developed and lies in same plane with palate.  Is in direct contact with bones of face and forms floor of orbit, roof of mouth and floor and lateral wall of nasal cavity www.indiandentalacademy.com
  •  Maxillary antrum - at birth has a slight depression on the lateral wall of nasal cavity opposite 2nd deciduous molar germ.  it’s growth displaces the erupting deciduous and permanent teeth www.indiandentalacademy.com
  •  Transverse palatine suture-according to Woo the palatine process of maxilla and horizontal parts of palatine bones overlap in an anterior direction.  Palate at birth - outer aspect has 2 parallel grooves.   external groove-dental groove inner -gingival groove. www.indiandentalacademy.com
  •  Zygoma – anteriorly- joins maxilla through the 1st deciduous molar. Posteriorly through calcifying 1st permanent molar.  Zygomatic arch grows by lateral addition and medial resorption. www.indiandentalacademy.com
  • POSTNATAL GROWTH  General Methods of Growth :    Remodelling. Displacement Relocation www.indiandentalacademy.com
  •  Remodeling is a process of reshaping and resizing a growing bone as it is relocated to new levels.  Reason- while parts of bone are moved; it maintains the form of the whole bone and causes its enlargement. www.indiandentalacademy.com
  •  carried out by the osteogenic membranes and other surrounding soft tissues  bone itself contributes by feedback information  Bionator-tries to alter this equilibrium  Fields of remodeling- resorptive and depository on the outside and inside of bone  Clinical significance-distalisation of molar www.indiandentalacademy.com
  •      Displacement – the whole bone is carried by a mechanical force Site -Articular contacts 1° displacement –the physical carry takes place in conjunction with the bones own enlargement vectors oriented–posteriorly and superiorly bone displaced – anteriorly and inferiorly www.indiandentalacademy.com
  •   2° displacement - movement of bone and soft tissues not directly related to its enlargement. Temporal lobe of cerebrum  Middle cranial fossa  Displace nasomaxillary complex downwards and forwards www.indiandentalacademy.com
  • primary movement-displacement or remodelling?  displacement is presently believed by many researchers to be the primary change with rate and direction of bone growth representing a secondary (transformative) response  It is also believed that both may be responding to common signals that separately but simultaneously activate both to operate in unison www.indiandentalacademy.com
  •  Domino effect – Growth changes are passed on from region to region to produce a secondary spin off in areas quite distant. Such effects are cumulative. www.indiandentalacademy.com
  •  Rotation –2 types   Remodelling rotation Displacement rotation.  Nasomaxillary complex- displacement rotation in either a clock or counter clock wise direction depending on growth activities of basicranium and sutural system.  Palate- remodeling rotation occurs in a counter direction. www.indiandentalacademy.com
  • NASOMAXILLARY COMPLEX   Remodeling - Posterosuperiorly Displacement – Anteroinferiorly Remodeling –       Lacrimal suture Max tuberosity Vertical drift of teeth Nasal airway Palatal remodelling. www.indiandentalacademy.com
  •  Lacrimal suture- is a bone surrounded by Osteogenic sutural connective tissue capable of responding to growth signals  allowing a slide of bones along their sutural surfaces;eg: it allows the maxilla to slide down its orbital contacts and thus displace inferiorly. www.indiandentalacademy.com
  •  Maxillary Tuberosity :major growth site  Post surface -deposition – lengthens arch Buccal surface – deposition – widens arch posteriorly Alveolar ridge and lateral side -deposition - downward growth Endosteal side -resorptive – sinus enlargement www.indiandentalacademy.com   
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  • Resorptive areas of nasomaxillary complex www.indiandentalacademy.com
  •  Vertical drift -As the maxilla and mandible enlarge and develop the teeth drift horizontally and vertically to keep pace in their anatomic positions.  the tooth and its alveolar socket drift together as a unit www.indiandentalacademy.com
  •  Palatal Remodelling -In a child the maxillary arch and nasal floor lie very close to the orbital rim. Remodelling results in downward relocation of the palate so that the arch lies considerably below the inferior orbital rim.  nasal region of the adult occupies an area where the bony max arch used to be located during childhood. www.indiandentalacademy.com
  •  The palate widens according to Enlows V principle.  Also growth at the mid palatal suture widens the palate and the alveolar arch In RPE - maxilla is1st displaced laterally; remodelling of the displaced segments follows  www.indiandentalacademy.com
  •   Nasal airway remodelingethmoidal concha    deposition-lateral and inferior surface resorption-superior and medial surface This moves them downwards and laterally www.indiandentalacademy.com
  •  Displacement- Maxilla   primary displacement-antero -inferior direction grows and lengthens- posteriorly www.indiandentalacademy.com
  • Maxillary sutures: Primary displacement-multidirectional and thus a slide of bones along interface occurs.  Nasomaxillary complex undergoes a frontal slide at junction with lacrimal, zygomatic, nasal and ethmoidal bones.  www.indiandentalacademy.com
  • Cheek bone and Zygomatic Arch  malar protuberance- relocates posteriorly Posterior side depository anterior side resorptive Zygoma -inferior edge-depository. Zygomatic arch -laterally and inferiorly Deposition- laterally downwards  resorption -opposite cortical sides  www.indiandentalacademy.com
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  • Orbital Growth  Orbital roof -floor of anterior cranial fossa remodels antero-inferiorly  Lateral wall - resorption medially deposition laterally  Floor of the orbit-remodels upwards deposition-superiorly resorption-inferiorly www.indiandentalacademy.com
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  • Growth of maxilla  Earliest concept – maxillary growth pushes it against pterygoid plates causing a resultant force on it anteriorly  discarded coz - bone’s osteogenic membrane is pressure sensitive and compression of capillary plexus causes necrosis. www.indiandentalacademy.com
  •  Acc to Moss 3 types of bone growth changes are to be observed in the maxilla.  Due to 1)primary expansion of the orofacial capsule.  2) alterations in maxillary functional matrices eg: orbital mass.  3) maintenance of the form of the bone www.indiandentalacademy.com
  •  Enlow and Bang- principle of “area relocation”  As growth continues, “specific local areas come to occupy new actual positions in succession, as the entire bone enlarges. These growth shifts and changes involve corresponding and sequential remodeling adjustments in order to maintain the same shape, relative position and constant proportion of each individual area in maxilla as a whole” www.indiandentalacademy.com
  •  STH-somatomedin Direct effect-stimulates preosteoblasts prechondroblasts  Indirect effect-growth of septal cartilage 1. Thrust effectgrowth of septal cartilage-thrust on premaxilla-stimulates growth of suture  Histologically-collagen fibers connecting cartilage and bone www.indiandentalacademy.com
  • 2 Septopremaxillary ligament traction effect  Forward growth of septal cartilage-traction effect on premaxilla-through this ligament  Studies(Petrovic;Stutzmann)-showed greater osteoblastic at this ligament junction with premaxilla  Histologically-ligament not able to provide traction  After resection-it has a local,induction like stimulating effect on subperiosteal growth www.indiandentalacademy.com
  • 3 Labionarinary muscle traction effect-  Septal cartilage growth produces traction on premaxilla through this muscle causing forward growth of upper jaw.  Cleft lip-absence of muscle attachment on nasal septum-bone malformations  Unilateral resection-unilateral decreased growth of operated side www.indiandentalacademy.com
  •  What is the primary growth center or pacemaker for the maxilla?  Moss and Greenberg-basic maxillary skeletal unit infraorbital neurovascular triad.basal boneprotection mechanism for the trigeminal nerve.This neurotrophic influence maintains the spatial constancy for the infraorbital canal with respect to the anterior cranial base and produces a similar constancy of the basal maxillary skeletal unit relative to the cranial base. www.indiandentalacademy.com
  • NEUROCRANIUM  The original pattern of skeleton-maintained. Stationary biologic center-body of the sphenoid  The Basicranium - “template” that establishes the growth fields within which nasomaxillary complex grows www.indiandentalacademy.com
  •   endocranial surface-resorptiveReason-sutures cant provide for multiple directions of enlargement and remodeling Fossa enlargement- direct remodeling   deposition-outside resorption -inside www.indiandentalacademy.com
  •  endocranial compartments-separated by bony partitions    depository in nature. reason-fossae expand outward by resorption, the partitions between them must enlarge inward, in proportion, by deposition. Remodeling of basicranium -stability for nerve and vessels . The foramen undergo drift to maintain proper position www.indiandentalacademy.com
  •       Synchondroses- retention from primary cartilages of chondrocranium after the endochondral ossification centers appear during fetal development Pressure adapted bone growth Sphenoethmoidal-5 to 25 years (max contribution- 6yrs) intersphenoidal- disappears at birth spheno-occipital intraoccipital - 3rd to 5th year www.indiandentalacademy.com
  •  Recent research shows SE synchondrosis has important ramifications in cleft palate rehabilitation.  synchondroses are primary centers of growth is supported by research of Sarnat, Burdi, Baume, Petrovic, and others.  Koski says these exist primarily to adjust the cranial base to needs of the brain and respiratory area. www.indiandentalacademy.com
  •  sphenoid and occipital bones move apart by primary displacement , and endochondral bone is laid down by the endosteum within each bone.  cortical (intramembranous) bone formed around the endochondral bone www.indiandentalacademy.com
  •  Synchondrosis zones- reserve, cell division, hypertrophic, and calcified zones.  Chondroblasts -aligned in distinctive columns along line of growth,with bipolar direction of linear growth www.indiandentalacademy.com
  •  Is displacement caused by growth expansion, or the endochondral growth a response to displacement caused by other forces?  Does the cartilage have an intrinsic genetic program that actually regulates growth? www.indiandentalacademy.com
  •  Cranial cartilages-autonomous growth units that develop in conjunction with the brain, but somehow independent of it.  Experimental studies show the independent proliferative capacity of synchondrosis is not greater than epiphyseal plates (more than condylar cartilage) suggesting extrinsic control factors are also required www.indiandentalacademy.com
  •  synchondrosis relates to the midventral axis and not the entire cranial floor.  Enlargement   Midline-less middle cranial fossae-more because it houses the various lobes which enlarge much more(laterally) www.indiandentalacademy.com
  • Effect on maxillary complex  middle cranial fossa-causes secondary displacement of nasomaxillary complex  maxillary complex posterior boundary positioned to coincide with the boundary between the anterior and middle cranial fossa www.indiandentalacademy.com
  •  Temporal and frontal lobes expand (5-6 yrs).     two fossae- pulled away tension fields in the frontal, temporal, sphenoidal, and ethmoidal sutures. Both fossae-enlarge nasomaxillary complex is carried along anteriorly www.indiandentalacademy.com
  •  Acc to Weinmann and Sicher the sutures are all oblique and parallel to each other. Thus causing the maxilla to move downward and forward (or the cranium upward and backward).  Sutures- increase the circumference bones involved www.indiandentalacademy.com
  •  Hunter and Enlow-growth equivalents theory  analyzed the effect cranial base growth on facial growth  emphasize both the timing of endochondral and intramembranous growth and the correlation of vectors and increments www.indiandentalacademy.com
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  •  Sicher sutural growth theory-  growth at maxillary sutures-pushes bone apart causing anteroinferior thrust on maxilla  discarded as - suture growth is tension adapted and is not adapted to pressure.  now believed-displacement of a bone produces tension which acts as a stimulus for sutural bone growth www.indiandentalacademy.com
  •  Scotts cartilaginous growth theory  It is specifically adapted to pressure related growth  Supported by research by Ohyama on rats In cleft palate cases,nasal septum grows normally   inhibition of sutural growth considered as of lack of cartilage growth –no cartilage growth, no sutural growth, no proliferation of connective www.indiandentalacademy.com tissue.
  •  Scott attributed an epiphyseal plate like effect to the nasal septum.  Recent research shows- nasal septum seems more important in anteroposterior than vertical growth.  Questioning Scott’s hypothesis –   periosteal growth is controlled by intrinsic factors why the periosteal membrane should be different in its action than sutural growth www.indiandentalacademy.com
  • Functional matrix concept  any given bone grows in response to functional relationships established by the sum of all soft tissues operating in association with that bone.  functional matrix is apparent in craniostenosis; discontinuation of sutural growth of calvaria, with the brain still growing, pressure is exerted on other areas, causing the eye to bulge, and producing other effects www.indiandentalacademy.com
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  •  Brain rests on the chondrocranium and theoretically exerts the same amount of force downward as it would on desmocranium.  This apparent high degree of independence of bone growth is further substantiated by the fact that it is very difficult to distort the chondrocranium in contrast to desmocranium.  Thus, there is apparent support for part of the Scott hypothesis while much research supports the Moss functional matrix explanation www.indiandentalacademy.com
  • Multiple Assurance – by Latham and Scott 1970 The process and mechanisms that function to carry growth are multifactorial. If 1 becomes inoperative other components have a capacity to ‘compensate’ ie: provide alternate means to achieve same developmental and functional and result. www.indiandentalacademy.com
  • Van limborgh’s theory  synchondroses and endochondral ossification- controlled by intrinsic genetic factors.  intrinsic factors controlling intramembranous bone growth are small in number and of a general nature.  cartilaginous skull parts- growth centers. www.indiandentalacademy.com
  •  sutural growth-controlled by cartilaginous growth and growth of other structures.  periosteal bone growth depends on the growth of adjacent structures.  intramembranous bone formation can also be influenced by local environmental factors. www.indiandentalacademy.com
  • Cybernetic theory www.indiandentalacademy.com
  • THE DEVELOPMENTAL SEQUENCE Balanced growth-form and proportion remain constant  The face –balanced+ imbalanced craniofacial parts  Enlow’s counterpart principle-growth of any given part relates specifically to other structural and geometric parts  Part and counterpart grow equal-balanced growth  Unequal-imbalanced growth www.indiandentalacademy.com 
  •  Stage 1-  remodeling of maxillary tuberosity  PTM moves posteriorly  Maxillary arch length increases same amount as PTM moves posteriorly www.indiandentalacademy.com
  •  Stage2-  displacement anteriorly  Amount of fwd displacement equals amount of posterior lengthening www.indiandentalacademy.com
  •  Stage3-  temporal lobes and middle cranial fossa –remodel  The expansion projects it beyond reference line www.indiandentalacademy.com
  •  Stage4-  All parts anterior to reference line-displaced forwards  Reference line moves-same extent as MCF  Maxillary tuberosity-constant www.indiandentalacademy.com
  •  Stage5-  floor ACF and forehead      Deposition-ectocranium side Resorption-endocranial side Nasal bone displaced anteriorly ACF-in balance with maxillary arch Nasal region-equivalent growth increments horizontally www.indiandentalacademy.com
  •  Stage6-  vertical lengthening of nasomaxillary region   Primary displacement Remodelingresorption-superior part of palate  Deposition-inferior side   Thus relocating it inferiorly ;thereby providing for vertical enlargement of above nasal www.indiandentalacademy.com region
  •  Stage7-  bone deposition –maxillary sutures  equal to –maxillary displacement inferiorly  Palate and maxilla  1-2- remodeling 2-3 primary displacement and sutural growth   Teeth  1-2 –vertical drift 2-3-displacement of www.indiandentalacademy.com maxilla
  •  Stage 8  zygoma and malar arearemodel posteriorly www.indiandentalacademy.com
  •  Stage 9-  malar area-primary displacement-anteriorly and inferiorly www.indiandentalacademy.com
  • Changes in growing face Postnatally face increases primarily in length, less in A-P depth and least in lateral width.  At birth Width - 57% of adult   Height- 40% Depth - 33% www.indiandentalacademy.com
  •  Face height –  cartilages of nasal septum, upper facial skeleton and condyle determine the direction of growth of face height.  From mid-fetal life to 5 years facial growth increases by 1/3.  Face shows a sustained and longer duration growth. www.indiandentalacademy.com
  •  Face depth –  According to meredith  the face depth increases at a slower rate as age increases.  Avg face depth is approx 3% larger in boys than girls. www.indiandentalacademy.com
  •  Sex differences in Face Growth –  Girls complete A-P growth at puberty while boys continue till maturity.  Girls face grows in height more than males till 15 years.  Males - growth - Depth > Height > Width Female - growth -Depth > Height –(upto 11 yrs) Height > Depth – (11-18yrs) www.indiandentalacademy.com 
  • NORMAL VARIATION AND MALOCCLUSION  Range of facial differences exists- brainlarge and variable Broadly divided into    Dolichocephalic Brachycephalic www.indiandentalacademy.com
  •  Brachycepahlic Wider and A-P shorter basicranium  Closed basicranial flexure  Vertically and protrusively shorter ;wider midface  the anterior cranial fossa sets up a wider but shorter and more shallow palate and maxilla. www.indiandentalacademy.com
  •  Nasomaxillary complexretrusively placed  horizontal length short  Composite result -relative retrusion www.indiandentalacademy.com
  •  DolicocephalicLong and narrow basicranium elongate and open and basicranial flexure A-P and vertical elongate facial pattern anterior cranial fossa sets up a www.indiandentalacademy.com narrower and deeper maxillary
  •  nasomaxillary complex- protrusive position; lowered relative to the condyle downward and backward rotation of mandible Occlusal plane rotated in a downward-incline www.indiandentalacademy.com
  • Male versus female Dolichocephalic- features parallel those of the male face Brachycephalic- features parallel those of the female face. Comparison- is relative whole body and lung size www.indiandentalacademy.com
  • Child versus adult  Youthful face- brachycephalic brain precocious relative to facial development.  facial and pharyngeal airway is yet small  Anterior cranial fossa is developmentally precocious-nasomaxillary complex- carried to a more protrusive position than the mandible www.indiandentalacademy.com
  •  face is vertically short because  Nasal part of the face is still diminutive  Primary and secondary dentition not fully established  Jaw bones not yet grown to the vertical extent. www.indiandentalacademy.com
  •  Forward and downward inclined middle cranial fossa     maxillary protrusive mandibular retrusive effect Maxilla- offset anteriorly Mandible- down and back Class II molar relationship www.indiandentalacademy.com
  •  Upwards and backward inclined middle cranial fossa     mandibular protrusion effect Maxilla- placed backward Mandible-rotates in a protrusive position. Class III molar relationship www.indiandentalacademy.com
  •  Nasomaxillary complexvertically long   Mandible- downward-backward rotation Class II molar relationship www.indiandentalacademy.com
  •  Nasomaxillary region vertically short  mandibular -protrusive effect  Mandible rotates forward and upward  Class III molar relationship www.indiandentalacademy.com
  •  Maxillary retrusive and mandibular protrusive effects- www.indiandentalacademy.com
  •  Maxillary protrusive and mandibular retrusive effects- www.indiandentalacademy.com
  •  EFFECT OF NASOPHARYNGEAL AIRWAY Acc to Moss functional spaces (oral, nasal, pharyngeal) are not simply left over areas; but volumetric growth of these spaces is 1° morphogenetic event in facial skull growth. The functional reality of respiratory and digestive system is patency of these space www.indiandentalacademy.com
  •  Theories proposing a relationship between mouth breathing and dentofacial form- I. COMPRESSION THEORY II. DISUSE ATROPHY THEORY. III.ALTERED AIR PRESSURE. IV.SOFT TISSUE STRETCH HYPOTHESIS www.indiandentalacademy.com
  •  Compression Theory-Tomes-1872. Enlarged adenoids Low tongue position Unbalanced muscle equilibrium Excessive force on maxillary arch buccal segments V-shaped dental arches. www.indiandentalacademy.com
  •  Disuse Atrophy Theory: inactivity of nasal cavity causes an alteration in maxillary arch  Nordlund (1918)- obstruction of nasal respiration due to adenoids nasal cavity undergo disuse atrophy relative elevation of palatal vault as alveolar process grows downward www.indiandentalacademy.com
  •  Moss stated that in Congenital Bilateral Choanal Atresia - absence of Nasorespiratory function.  Marked underdeveloprment of functional space occurs www.indiandentalacademy.com
  •  Altered Air Pressure:  alteration of air pressure within nasal and oral cavities during mouth breathing effects dentofacial form.  Bloch (1903) and Michel (1908) upward stream of oral airflow pressure on palate leads to higher palatal vault. www.indiandentalacademy.com
  •  Kantorowicz (1916) and James and Hastings (1932) In mouth breathing negative pressure in sealed oral cavity lost Palate not carried downward with growth of maxillary alveolar process www.indiandentalacademy.com
  •  Soft Tissue Stretch Hypothesis: Solow and Kreiborg (1977)  Posturally induced stretching of soft tissue of facial region might influence craniofacial morphological development  Hypothetically an extension of head, i.r.t cervical column - passive stretching of soft tissue enclosing face and neck.  www.indiandentalacademy.com Effect-backward and downward forces
  • In adenoid obstruction -increased cranio cervical angulation.  changes in Craniofacial morphology corresponding to this changed head posture.  www.indiandentalacademy.com
  • Studies showing association between nasopharyngeal obstruction and dentofacial form Experimental studies done on primates-  (1973) They blocked the Nasal passages of Rhesus monkeys and the monkeys gradually adapted from Nasal breathing to oral respiration HARVOLD, CHIERICI & VARGERVIK www.indiandentalacademy.com
  •  Critical review of literature- by 0’ Ryan et al-  suggests that simple cause and effect relationship between nasorespiratory function and dentofacial development does not exist, rather it is a complex interaction between hereditary and environmental influences www.indiandentalacademy.com
  • The Role of Ear in determining facial form  It’s role as space occupying organ ambiguous and minimal. The internal ear reaches its adult size in- 5-6 month iu.  It is the only organ that reaches full adult size by this age and thus minimises any influence on subsequent growth of facial skeleton. www.indiandentalacademy.com
  • EVOLUTION OF HUMAN FACE  Brain Enlargement, Basicranial Flexure  cerebrum expands around smaller and lesser-enlarging midventral segment-causes a bending of the whole underside of the brain. The flexure of the basicranium results www.indiandentalacademy.com
  •  orbital rotation-  Two separate axes Vertical; horizontal  forehead- rotated into vertical plane by brain, the superior orbital rims are carried with it.  temporal lobes- rotate orbits towards the midline www.indiandentalacademy.com
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  •  Orbital rotation reduces the interorbital space and the structural base of the bony nose. www.indiandentalacademy.com
  •  Reduction in nasal protrusion accompanied less equivalent reduction of the upper jaw www.indiandentalacademy.com
  •   Downward rotation of olfactory bulbs and anterior cranial floor by the frontal lobes has caused a downward rotation of the nasomaxillary complex. .The plane of the nasomaxillary region -perpendicular to the olfactory bulbs. www.indiandentalacademy.com
  •    Nasomaxillary Configuration Mammals-triangular. Man-rectangular   rotation of occlusion in a horizontal plane adapting to the vertical rotation of the midface. suborbital compartmentoccupied by maxillary sinus www.indiandentalacademy.com
  •  Face also became markedly widened of the increased breadth of the brain.  The face now lies beneath the frontal lobes of the brain. www.indiandentalacademy.com
  •  downward – directed external nares aim the inflow of air obliquely upward towards sensory nerve endings in the olfactory bulbs www.indiandentalacademy.com
  • Growth Field Boundaries   forward boundary of the brain and nasomaxillary complex is shared A line is drawn from the forward edge of the brain to prosthion.-MIDFACIAL PLANE www.indiandentalacademy.com
  •  Upper boundary  the nasal part of the face relates to the olfactory bulbs and nerve. The nasomaxillary complex develops in a growth field out to the edge of the brain perpendicular to the olfactory bulbs. www.indiandentalacademy.com
  •  Posteriorly  Direction of growth- established visual sense. The maxillary tuberosity is located beneath the floor of the orbit and aligned perpendicular to its axis. www.indiandentalacademy.com
  •  The posterior plane of midface extends from junction between the anterior and middle cranial fossa,downwards in a direction perpendicular to the neutral axis of the orbit  Posterior maxillary (PM) plane.  developmental interface between counterparts ahead and behind it www.indiandentalacademy.com
  •  Inferior boundary- established when growth is complete by inferior surface of the brain and basicranium www.indiandentalacademy.com
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  • ANOMALIES  Unilateral, bilateral cleft lip  Oblique facial cleft and cleft lip  Median cleft lip and nasal defect  Median mandibular cleft  www.indiandentalacademy.com Unilateral microstomia
  •  Ancephaly Abs of neural crest cells – neurocristopathy  Treacher Collins syndrome  Anhidrotic ectodermal dysplasia  Downs syndrome  www.indiandentalacademy.com
  •  Cleft palate-  Cleft lip and palate  Fetal alcohol syndrome www.indiandentalacademy.com
  • CONCLUSION Nasomaxillary complex growth is a process requiring intimate morphogenic interrelationships among all of it’s component growing, changing and functioning soft and hard tissue parts. No part is developmentally independent and self contained. www.indiandentalacademy.com
  • Thank you www.indiandentalacademy.com Leader in continuing dental education www.indiandentalacademy.com