Congenital and developmental disorders of mandible

CONGENITAL ANDCONGENITAL AND
DEVELOPMENTAL DISTURBENCESDEVELOPMENTAL DISTURBENCES
OF MANDIBLE.OF MANDIBLE.
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DEVELOPMENT OF MANDIBLEDEVELOPMENT OF MANDIBLE
 Develops from firstDevelops from first
brachial arch.brachial arch.
 Mandibular process ofMandibular process of
both sides grow towardsboth sides grow towards
each other and fuse toeach other and fuse to
the midline.the midline.
 They form the lower lipThey form the lower lip
and jaw.and jaw.

 A single ossificationA single ossification
center for each half ofcenter for each half of
the mandible arises Inthe mandible arises In
the 6th week of IU lifethe 6th week of IU life
 Spread ofSpread of
intramembranousintramembranous
ossifcation dorsally andossifcation dorsally and
ventrally forms the bodyventrally forms the body
and ramus of theand ramus of the
mandible.mandible.

 Intramembranous ossification continues to formIntramembranous ossification continues to form
the body and ramus, whereas the condylarthe body and ramus, whereas the condylar
regions and coronoid processes are formed inregions and coronoid processes are formed in
cartilage.cartilage.
 this cartilage arises later than the primarythis cartilage arises later than the primary
chondracranial cartilage ,hence termed aschondracranial cartilage ,hence termed as
secondary csecondary cartilageartilage..

 This cartilage appears asThis cartilage appears as
a cone in the ramusa cone in the ramus
during the 12th week ofduring the 12th week of
development.development.
 The large end assumesThe large end assumes
the portion of the futurethe portion of the future
condyle.condyle.

 By the 20th week, the wedge of cartilage isBy the 20th week, the wedge of cartilage is
converted to bone except for a thin layer at theconverted to bone except for a thin layer at the
articular surface.articular surface.
 The cartilage that serves as a precursor of theThe cartilage that serves as a precursor of the
Coronoid process appears at about 4th monthCoronoid process appears at about 4th month
of development and is converted to bone beforeof development and is converted to bone before
birth.birth.

 Three forms of growth can be seen in mandible:Three forms of growth can be seen in mandible:
 1.Vertical1.Vertical
 2.Transverse2.Transverse
 3.Rotational3.Rotational

 VerticaLVerticaL growthgrowth of theof the
mandible is quitemandible is quite
pronounced. Thepronounced. The
mandible has to keepmandible has to keep
pace with the descent ofpace with the descent of
the maxilla and also itthe maxilla and also it
must maintain themust maintain the
interocclusal verticalinterocclusal vertical
dimension.dimension.

 TheThe transversetransverse growthgrowth ofof
the mandible is achievedthe mandible is achieved
principally by theprincipally by the
divergence of thedivergence of the
condyles as they growcondyles as they grow
posteriorly (Enlow's ‘v’posteriorly (Enlow's ‘v’
principle).principle).

 buccal bone depositionbuccal bone deposition
on the body and ramuson the body and ramus

 In Rotational growthIn Rotational growth thethe
matrix surrounding thematrix surrounding the
mandible acts tomandible acts to
moderate the shapemoderate the shape
changes of the bonechanges of the bone
rotating within it.rotating within it.

CONGENITAL AND DEVELOPMENTALCONGENITAL AND DEVELOPMENTAL
ANOMALIESANOMALIES
Congenital diseaseCongenital disease : is one which is present at or: is one which is present at or
before birth but is not necessarily inherited i.e.before birth but is not necessarily inherited i.e.
transmitted through the genes.transmitted through the genes.
Developmental anomaly ;Developmental anomaly ; unusual sequelae ofunusual sequelae of
development; a deviation from normal shape ordevelopment; a deviation from normal shape or
sizesize

DEVELOPMENTAL ANOMALIESDEVELOPMENTAL ANOMALIES
OF MANDIBLEOF MANDIBLE
 What are the potential disturbances of normalWhat are the potential disturbances of normal
jaw development?jaw development?
 Failure of the neural crest to form from theFailure of the neural crest to form from the
margins of the neural tube.margins of the neural tube.
 Slowed migration of crest cells away fromSlowed migration of crest cells away from
the neural tube.the neural tube.
 Defective mitotic division of neural crestDefective mitotic division of neural crest
cells.cells.
 Increased neural crest cell adhesion.Increased neural crest cell adhesion.
 An unusually high rate of neural cell deathAn unusually high rate of neural cell death

 A failed epithelial-mesenchymal interaction inA failed epithelial-mesenchymal interaction in
either the maxilla or mandibular prominences,either the maxilla or mandibular prominences,
this prevents bone cell differentiation.this prevents bone cell differentiation.
 Defect of the influence of related nerves,Defect of the influence of related nerves,
muscles or blood vessels.muscles or blood vessels.

DVELOPMENTAL ANOMALIESDVELOPMENTAL ANOMALIES
 Result of factors likeResult of factors like
GENETICGENETIC::
Include chromosomal aberrations and disordersInclude chromosomal aberrations and disorders
arising from abnormal genes or gene combinations.arising from abnormal genes or gene combinations.
Environmental:Environmental:
Include infections,drugs,chemical agents andInclude infections,drugs,chemical agents and
maternal metabolic factors.maternal metabolic factors.
 Develops predominantly during embryonic periodDevelops predominantly during embryonic period
from fourth to eighth week. (critical time)from fourth to eighth week. (critical time)

DEVELOPMENTAL DEFECTSDEVELOPMENTAL DEFECTS
 Developmental defects ofDevelopmental defects of
mandible.mandible.
 Developmental defects ofDevelopmental defects of
temporomandibular joints.temporomandibular joints.

AGNATHIAAGNATHIA
 Characterized by hypoplasiaCharacterized by hypoplasia
or absence of mandible.or absence of mandible.
 More commonly, only aMore commonly, only a
portion of jaw is missing.portion of jaw is missing.
 Partial absence of mandible isPartial absence of mandible is
more common.more common.
 Entire mandible on one sideEntire mandible on one side
may be missing or moremay be missing or more
frequently, only the condylefrequently, only the condyle
or the entire ramus.or the entire ramus.
 Bilateral agenesis of condylesBilateral agenesis of condyles
and ramus have also beenand ramus have also been
reported.reported.

 In case of unilateral absence of mandibular ramus,earsIn case of unilateral absence of mandibular ramus,ears
may be deformed or absent.may be deformed or absent.
 This is believed to be due to failure of migration ofThis is believed to be due to failure of migration of
neural crest mesenchyme into maxillary prominence atneural crest mesenchyme into maxillary prominence at
the fourth to fifth week of gestation(postconception)the fourth to fifth week of gestation(postconception)
 PROGNOSIS:PROGNOSIS:
poor and it is considered to be lethal.poor and it is considered to be lethal.

MICROGNATHIAMICROGNATHIA
 Means small jaw, eitherMeans small jaw, either
the maxilla or mandiblethe maxilla or mandible
may be involved.may be involved.
 Some cases may produceSome cases may produce
illusion of micrognathiaillusion of micrognathia
due to abnormaldue to abnormal
positioning or abnormalpositioning or abnormal
relation of one jaw to therelation of one jaw to the
other.other.

 True micrognathia is classified as:True micrognathia is classified as:
>congenital.>congenital.
>acquired.>acquired.

CONGENITALCONGENITAL
 Etiology:Etiology: being unknown, it is associated withbeing unknown, it is associated with
other congenital abnormalities likeother congenital abnormalities like congenitalcongenital
heart disease and pierre robin syndrome.heart disease and pierre robin syndrome.
 Follows a hereditary pattern.Follows a hereditary pattern.
 Agenesis of condyles results in true microgathia.Agenesis of condyles results in true microgathia.

 Some patients appear clinically to have severe retrusionSome patients appear clinically to have severe retrusion
of the chin but, by actual measurements, the mandibleof the chin but, by actual measurements, the mandible
may be found within the normal limits.may be found within the normal limits.
 Such cases may be due to posterior positioning of theSuch cases may be due to posterior positioning of the
mandible with regard to the skull or to a steepmandible with regard to the skull or to a steep
mandibular angle resulting in apparent retrusion ofmandibular angle resulting in apparent retrusion of
mandible.mandible.
 In these situations it is often difficult to specify theIn these situations it is often difficult to specify the
condition as true micrognathia.condition as true micrognathia.

ACQUIRED MICROGNATHIAACQUIRED MICROGNATHIA
 It is of postnatal origin.It is of postnatal origin.
 Usually results from a disturbanceUsually results from a disturbance
in the area of temporomandibularin the area of temporomandibular
joint.joint.
 Since the normal growth of theSince the normal growth of the
mandible depend on normallymandible depend on normally
developing condyles as well asdeveloping condyles as well as
muscles,condylar ankylosis maymuscles,condylar ankylosis may
result in deficient mandible.result in deficient mandible.
 Clinically it is characterized byClinically it is characterized by
severe retrusion of the chin, a steepsevere retrusion of the chin, a steep
mandibular angle, and a deficientmandibular angle, and a deficient
chin button.chin button.

Congenital conditionsCongenital conditions
 Catel-Manzke syndromeCatel-Manzke syndrome
 Cerebrocostomandibular syndromeCerebrocostomandibular syndrome
 Cornelia de Lange syndromeCornelia de Lange syndrome
 Femoral hypoplasia-unusual facies syndromeFemoral hypoplasia-unusual facies syndrome
 Fetal aminopterin-like syndromeFetal aminopterin-like syndrome
 Miller-Dieker syndromeMiller-Dieker syndrome
 Nager acrofacial dysostosisNager acrofacial dysostosis
 Pierre Robin syndromePierre Robin syndrome
 Schwartz-Jampel-Aberfeld syndromeSchwartz-Jampel-Aberfeld syndrome
 van Bogaert-Hozay syndromevan Bogaert-Hozay syndrome

Intrauterine acquired conditionsIntrauterine acquired conditions
 Syphilis.Syphilis.
 Chromosomal abnormalitiesChromosomal abnormalities

49,XXXXX syndrome49,XXXXX syndrome
 Chromosome 8 recombinant syndromeChromosome 8 recombinant syndrome
 Cri du chat syndrome 5pCri du chat syndrome 5p
 Trisomy 18Trisomy 18
 Turner's syndromeTurner's syndrome
 Wolf-Hirschhorn syndromeWolf-Hirschhorn syndrome

Mendelian inherited conditionsMendelian inherited conditions
 CODAS (cerebral, ocular, dental, auricula'CODAS (cerebral, ocular, dental, auricula'
 skeletal) syndromeskeletal) syndrome
 Diamond-Blackfan anemiaDiamond-Blackfan anemia
 Noonan's syndromeNoonan's syndrome
 Opitz-Frias syndromeOpitz-Frias syndrome
Autosomal dominant conditionsAutosomal dominant conditions
 Camptomelic dysplasiaCamptomelic dysplasia
 Cardiofaciocutaneous syndromeCardiofaciocutaneous syndrome
 CHARGE syndromeCHARGE syndrome
 DiGeorge's syndromeDiGeorge's syndrome
 Micrognathia with peromeliaMicrognathia with peromelia
 Pallister-Hall syndromePallister-Hall syndrome
 Treacher Collins-Franceschetti syndromeTreacher Collins-Franceschetti syndrome
 Trichorhinophalangeal syndrome type 1Trichorhinophalangeal syndrome type 1
 Trichorhinophalangeal syndrome type 3Trichorhinophalangeal syndrome type 3
 Wagner vitreoretinal degeneration syndromWagner vitreoretinal degeneration syndrom

AutosomalAutosomal recessive conditionsrecessive conditions
 Bowen-Conradi syndromeBowen-Conradi syndrome
 Carey-Fineman-Ziter syndromeCarey-Fineman-Ziter syndrome
 Cerebrohepatorenal syndromeCerebrohepatorenal syndrome
 Cohen syndromeCohen syndrome
 Craniomandibular dermatodysostosisCraniomandibular dermatodysostosis
 De la Chapel Ie dysplasiaDe la Chapel Ie dysplasia
 Dubowitz syndromeDubowitz syndrome
 Fetal akinesia-hypokinesia sequenceFetal akinesia-hypokinesia sequence
 Hurst's microtia-absent patellae-micrognathia syndromeHurst's microtia-absent patellae-micrognathia syndrome
 Kyphomelic dysplasiaKyphomelic dysplasia
 LathosterolosisLathosterolosis
 Lethal congenital contracture syndromeLethal congenital contracture syndrome
 Lethal restrictive dermopathyLethal restrictive dermopathy
 Marden-Walker syndromeMarden-Walker syndrome
 Orofaciodigital syndrome type 4Orofaciodigital syndrome type 4
 Postaxial acrofacial dysostosis syndromePostaxial acrofacial dysostosis syndrome
 Rothmund-Thomson syndromeRothmund-Thomson syndrome
 Smith-Lemli-Opitz syndromeSmith-Lemli-Opitz syndrome
 ter Haar syndrometer Haar syndrome
 Toriello-Carey syndromeToriello-Carey syndrome
 Weissenbacher-Zweymuller syndromeWeissenbacher-Zweymuller syndrome
 Yunis-Varon syndromeYunis-Varon syndrome

X-linked inherited conditionsX-linked inherited conditions
 Atkin-Flaitz-Patil syndromeAtkin-Flaitz-Patil syndrome
 Coffin-Lowry syndromeCoffin-Lowry syndrome
 Lujan-Fryns syndromeLujan-Fryns syndrome
 Otopalatodigital syndrome type 2Otopalatodigital syndrome type 2
Autoimmune conditionsAutoimmune conditions
 Juvenile chronic arthritisJuvenile chronic arthritis

MACROGNATHIAMACROGNATHIA
 Macrognathia refers toMacrognathia refers to
the condition ofthe condition of
abnormally large jaws.abnormally large jaws.
 An increase in both theAn increase in both the
jaws is frequentlyjaws is frequently
proportional toproportional to
generalized increase ingeneralized increase in
entire skeleton.entire skeleton.
 More commonly the jawsMore commonly the jaws
are affected.are affected.

 It is often associated with other conditions like:It is often associated with other conditions like:
 Paget’s disease of bone.Paget’s disease of bone.
 Acromegaly.Acromegaly.
 Leontiasis ossea.Leontiasis ossea.

 Clinically it occurs asClinically it occurs as
protrusion orprotrusion or
prognathism of mandibleprognathism of mandible
without any systemicwithout any systemic
complications.complications.
 Etiology:Etiology: unknown,unknown,
although some cases mayalthough some cases may
follow hereditaryfollow hereditary
patterns.patterns.

 In many instances theIn many instances the
prognathism is due toprognathism is due to
disparity in the size of maxilladisparity in the size of maxilla
to mandible.to mandible.
 The angle between the ramusThe angle between the ramus
and the body influence theand the body influence the
relation of mandible torelation of mandible to
maxilla.maxilla.
 Thus prognathic patientsThus prognathic patients
tend to have long rami whichtend to have long rami which
form a steep angle with theform a steep angle with the
body of the mandible.body of the mandible.

General factors which would influence andGeneral factors which would influence and
favor mandibular prognathism are:favor mandibular prognathism are:
 Anterior positioning of the glenoid fossa.Anterior positioning of the glenoid fossa.
 Decreased maxillary length.Decreased maxillary length.
 Posterior positioning of the maxilla in relation to thePosterior positioning of the maxilla in relation to the
cranium.cranium.
 Prominent chin button.Prominent chin button.
 Varying soft tissue contours.Varying soft tissue contours.
 Increased height of the ramus.Increased height of the ramus.
 Increased mandibular body length.Increased mandibular body length.
 Increased gonial angle.Increased gonial angle.

 TREATMENTTREATMENT ::
 Patient with prognathism frequently placePatient with prognathism frequently place
considerable stress and unfavorable leveragesconsiderable stress and unfavorable leverages
under complete denture.under complete denture.
 This may cause excessive reduction ofThis may cause excessive reduction of
maxillary ridge.maxillary ridge.
 So in these cases mandibularSo in these cases mandibular
Ostectomy/resectionOstectomy/resection>creates more favorable>creates more favorable
arch alignment and appearance.arch alignment and appearance.

 Preoperative diagnosticPreoperative diagnostic
cast of a patient.cast of a patient.

FACIAL HEMIHYPERTROPHYFACIAL HEMIHYPERTROPHY
 One of the rareOne of the rare
developmental disorder.developmental disorder.
 Asymmetric overAsymmetric over
growth of one or moregrowth of one or more
body parts.body parts.
 Represents hyperplasiaRepresents hyperplasia
rather than hypertrophy.rather than hypertrophy.
 It is of 3 types, namely:It is of 3 types, namely:

 Simple hyperplasia.Simple hyperplasia.
 Complex hyperplasia.Complex hyperplasia.
 Hemi facial hyperplasia.Hemi facial hyperplasia.
 Female: Male>2:1,often affecting on right side.Female: Male>2:1,often affecting on right side.

 Asymmetry starts at birth.Asymmetry starts at birth.
 Enlargement is more accentuated at theEnlargement is more accentuated at the
age of 6 and continues till the overallage of 6 and continues till the overall
growth ceases.growth ceases.
 Enlargement of the mandible and teethEnlargement of the mandible and teeth
on the affected side.on the affected side.
 The bone is wider and thicker.The bone is wider and thicker.
 Premature shedding of the deciduousPremature shedding of the deciduous
teeth.teeth.
 The roots of the teeth are sometimesThe roots of the teeth are sometimes
proportionately enlarged but may beproportionately enlarged but may be
shortshort
 Permanent teeth on the affected side isPermanent teeth on the affected side is
often enlarged, most frequentlyoften enlarged, most frequently
involving cuspid, premolars, and firstinvolving cuspid, premolars, and first
molarmolar
 Permanent teeth on affected sidePermanent teeth on affected side
develops more rapidly and erupt beforedevelops more rapidly and erupt before
there counterpart on the uninvolvedthere counterpart on the uninvolved
side.side.
 Macroglossia.Macroglossia. www.indiandentalacademy.com

 TREATMENTTREATMENT::
 No specific treatment ,other thanNo specific treatment ,other than cosmeticcosmetic
surgerysurgery..
 Surgery is done after the cessation ofSurgery is done after the cessation of
growth.growth.

PAGET’S DISEASEPAGET’S DISEASE
 Characterized by excessive growthCharacterized by excessive growth
and abnormal remodeling of boneand abnormal remodeling of bone
 Results in bones which are weak,Results in bones which are weak,
enlarged and extensivelyenlarged and extensively
vascularized.vascularized.
 EtiologyEtiology: unknown, there may be: unknown, there may be
evidence of genetic link.evidence of genetic link.
 Possible etiologic factorsPossible etiologic factors::
 Viral infections.Viral infections.
 InflammatoryInflammatory
causecause
 Autoimmune,Autoimmune,
connective tissue,connective tissue,
vascular disorders.vascular disorders.

 Recognized most commonly afterRecognized most commonly after
the age of 50 years.the age of 50 years.
 Its prevalence increases with age.Its prevalence increases with age.
 Male: female>1:1Male: female>1:1
 Jaws are involved more commonly.Jaws are involved more commonly.
 The most common complaint isThe most common complaint is
bone pain.bone pain.
 This pain is perceived as dullThis pain is perceived as dull
aching pain deep below the softaching pain deep below the soft
tissues.tissues.
 It may persist or exacerbate duringIt may persist or exacerbate during
the night.the night.
 The involved bone becomes warmThe involved bone becomes warm
to the touch due to increasedto the touch due to increased
vascularity.vascularity.

 The ratio of involvement of maxilla toThe ratio of involvement of maxilla to
mandible is 2.3:1.mandible is 2.3:1.
 The maxilla exhibits progressiveThe maxilla exhibits progressive
enlargement, the alveolar ridgeenlargement, the alveolar ridge
becomes widened and palate isbecomes widened and palate is
flattened.flattened.
 If teeth are present, they may becomeIf teeth are present, they may become
loose and migrate, producing someloose and migrate, producing some
amount of spacing.amount of spacing.
 When mandible is involved theWhen mandible is involved the
findings are similar, but not as severefindings are similar, but not as severe
as in maxilla.as in maxilla.
 Edentulous patients with denturesEdentulous patients with dentures
commonly complain of inability tocommonly complain of inability to
wear their appliances because ofwear their appliances because of
increasing tightness due to expansionincreasing tightness due to expansion
of the jaw.of the jaw.

 Early stages revealEarly stages reveal
decreased bone densitydecreased bone density
and altered trabecularand altered trabecular
pattern.pattern.
 Particularly in the skullParticularly in the skull
large circumscribed areaslarge circumscribed areas
of radiolucency may beof radiolucency may be
present, which is termedpresent, which is termed
as “as “osteoporosisosteoporosis
circumscripta”circumscripta”

 During osteoblasticDuring osteoblastic
phase, patch areas ofphase, patch areas of
sclerotic bone aresclerotic bone are
formed. (formed. (cotton woolcotton wool
appearanceappearance))

 On initial discovery ofOn initial discovery of
Paget's disease, bonePaget's disease, bone
scinitigraphy should bescinitigraphy should be
performed to evaluate theperformed to evaluate the
extent of involvement.extent of involvement.
 When mandible is affected,When mandible is affected,
the bone scan maythe bone scan may
demonstrate marked uptakedemonstrate marked uptake
throughout the entirethroughout the entire
mandible from condyle tomandible from condyle to
condyle.condyle.
 This feature is termed asThis feature is termed as
““black beard or Lincoln'sblack beard or Lincoln's
sign”sign”

LABORATORY FINDINGSLABORATORY FINDINGS
 The serum alkaline phosphatase level may beThe serum alkaline phosphatase level may be
elevated to the extreme limits.elevated to the extreme limits.
 In polystotic involvement > 250 Bodansky units.In polystotic involvement > 250 Bodansky units.
 In monostotic involvement > 50 BodanskyIn monostotic involvement > 50 Bodansky
units.units.
 In Paget's disease, urinary hydroxyproline levelsIn Paget's disease, urinary hydroxyproline levels
are elevated as they reflect increased osteoclasticare elevated as they reflect increased osteoclastic
activity and bone resorbtion.activity and bone resorbtion.

 Patients with limited involvement and noPatients with limited involvement and no
symptoms>Nosymptoms>No treatment requiredtreatment required..
 When Alkaline phosphatase is more thanWhen Alkaline phosphatase is more than
25% to 50%>25% to 50%>Systemic therapy is givenSystemic therapy is given
like:like:

 Parathyroid hormone antagonistsParathyroid hormone antagonists::
>calcitonin.>calcitonin.
>biphosphonates:>biphosphonates:
a.tiludronate.a.tiludronate.
b.risedronate.b.risedronate.
c.alendronate.c.alendronate.
d.pamidronate.d.pamidronate.

 In mild casesIn mild cases: single infusion of biphosphotase.: single infusion of biphosphotase.
 In severe casesIn severe cases: weekly or biweekly for few: weekly or biweekly for few
weeks.weeks.
 Edentulous patientsEdentulous patients: require new and larger: require new and larger
dentures periodically.dentures periodically.

COMPLICATIONSCOMPLICATIONS
 Incomplete stress fractures.Incomplete stress fractures.
 Mild injuries > true pathologic fractures in weakened pageticMild injuries > true pathologic fractures in weakened pagetic
bone.bone.
 Sarcomatous degeneration may occur.Sarcomatous degeneration may occur.
 Degenerative joint diseaseDegenerative joint disease
 Cardiovascular abnormalities > increased cardiac output.Cardiovascular abnormalities > increased cardiac output.

Left ventricular hypertrophy.Left ventricular hypertrophy.

 Frequent sites of pathologic fracturesFrequent sites of pathologic fractures::
 femur.femur.
 Tibia.Tibia.
 Humerus.Humerus.
 Spine.Spine.
 Pelvis.Pelvis.

MANDIBULAR DYSOSTOSISMANDIBULAR DYSOSTOSIS
 Characterized by defectsCharacterized by defects
of structures arising fromof structures arising from
firstfirst andand secondsecond brachialbrachial
arches.arches.
 Autosomal dominant.Autosomal dominant.
 Gene for this wasGene for this was
mapped to chromosomemapped to chromosome
5q32-q33.15q32-q33.1

 A notch appears on the outerA notch appears on the outer
portion of the lower eye lids.portion of the lower eye lids.
 There is deficiency of the eye lids.There is deficiency of the eye lids.
 Ears may be deformed.Ears may be deformed.
 Mandible is under developed withMandible is under developed with
retruded chin.retruded chin.
 Malocclusion of the teeth.Malocclusion of the teeth.
 Cleft palate > 1/3 of cases.Cleft palate > 1/3 of cases.
 Parotid gland may be hypoplasticParotid gland may be hypoplastic
or totally absent.or totally absent.
 Respiratory and feeding difficultiesRespiratory and feeding difficulties
in infants due to hypoplasia of thein infants due to hypoplasia of the
nasopharynx, oropharynx, andnasopharynx, oropharynx, and
hypopharynx.hypopharynx.

 Characteristic facial feature isCharacteristic facial feature is
bird like or fish like.bird like or fish like.
 Mild casesMild cases: no: no
treatment.treatment.
 Severe casesSevere cases: Cosmetic: Cosmetic
surgerysurgery
 CombinedCombined
orthodontic therapyorthodontic therapy
along withalong with
orthognathic surgery.orthognathic surgery.

CHERUBISMCHERUBISM
 Autosomal dominant.Autosomal dominant.
 The gene is mapped toThe gene is mapped to
chromosome 4p16.chromosome 4p16.
 Facial appearance isFacial appearance is
similar to plump-similar to plump-
cheeked, hence the namecheeked, hence the name
cherubism.cherubism.
 First described in theFirst described in the
yearyear 1953 by Jones1953 by Jones..

 Jaw lesions are usuallyJaw lesions are usually
painless and symmetric.painless and symmetric.
 Lesions which are firmLesions which are firm
and non tender toand non tender to
palpate involvepalpate involve molar tomolar to
coronoid regionscoronoid regions, often, often
associated withassociated with cervicalcervical
lymphadenopathy.lymphadenopathy.
 This contributes toThis contributes to fullfull
faced appearancefaced appearance causedcaused
byby lymphoid hyperplasialymphoid hyperplasia..

 Lymph nodes enlarge at theLymph nodes enlarge at the
age of 6 and decrease et theage of 6 and decrease et the
age of 8.age of 8.
 These lesions tend to showThese lesions tend to show
varying degree of remissionvarying degree of remission
and involution after puberty.and involution after puberty.
 This radiograph showsThis radiograph shows
bilateral multilocularbilateral multilocular
radiolucencies in theradiolucencies in the
posterior mandible in a 7 yearposterior mandible in a 7 year
old male.old male.

 Same patient 6 years later. theSame patient 6 years later. the
lesions demonstratelesions demonstrate
significant resolution, butsignificant resolution, but
areas of involvement are stillareas of involvement are still
present in the body of thepresent in the body of the
mandible.mandible.
 There may beThere may be
displacment,rotation of thedisplacment,rotation of the
teeth.teeth.
 Premature exfoliation,Premature exfoliation,
delayed eruption.delayed eruption.

GRADINGGRADING
 BY ARNOT (1978).BY ARNOT (1978).
 Grade 1Grade 1 > Characterized by involvement> Characterized by involvement
of both mandibular ascending rami.of both mandibular ascending rami.
 Grade 2Grade 2 >Involvement of both maxillary>Involvement of both maxillary
tuberosities and mandibular ascendingtuberosities and mandibular ascending
rami.rami.
 Grade 3Grade 3 >Involving whole of maxilla and>Involving whole of maxilla and
mandible except the coronoid and condylarmandible except the coronoid and condylar
process.process.

TREATMENTTREATMENT
 Early surgical intervention with curettage of the lesion.Early surgical intervention with curettage of the lesion.
 Some times the early intervention may cause rapidSome times the early intervention may cause rapid
regrowth of the lesion and worsen the condition.regrowth of the lesion and worsen the condition.
 As stated by laskin(1985)As stated by laskin(1985)
 ““The treatment of cherubism should be based onThe treatment of cherubism should be based on
the unknown natural course and the clinicalthe unknown natural course and the clinical
behavior of individual case.”behavior of individual case.”
 Hence if it is necessary surgery is done after theHence if it is necessary surgery is done after the
remission phase (after the puberty)remission phase (after the puberty)
 Severe cases ----- calcitonin.Severe cases ----- calcitonin.

EXOSTOSESEXOSTOSES
 These are localized bonyThese are localized bony
protuberance arisingprotuberance arising
from the cortical plate.from the cortical plate.
 These are of benign inThese are of benign in
nature.nature.
 Often discovered inOften discovered in
adults.adults.

 Occur as a bilateral row ofOccur as a bilateral row of
bony hard nodules alongbony hard nodules along
the facial aspect ofthe facial aspect of
maxilla/mandibular alveolarmaxilla/mandibular alveolar
ridge.ridge.
 Usually asymptomaticUsually asymptomatic
unless the thin mucosalunless the thin mucosal
covering is ulcerated due tocovering is ulcerated due to
trauma.trauma.
 Torus mandibularisTorus mandibularis is oneis one
of the best known oralof the best known oral
exostoses.exostoses.

TORUS MANDIBULARISTORUS MANDIBULARIS
 Develops along theDevelops along the
lingual aspect of thelingual aspect of the
mandible, just above themandible, just above the
mylohyoid line in themylohyoid line in the
region of premolars.region of premolars.
 Etiology:Etiology:
geneticgenetic/environmental./environmental.
 Bilateral involvementBilateral involvement
occurs in more than 90%occurs in more than 90%
of cases.of cases.

 May be single/multipleMay be single/multiple
nodules.nodules.
 Asymptomatic unless theAsymptomatic unless the
overlying mucosa is ulceratedoverlying mucosa is ulcerated
due to secondary trauma.due to secondary trauma.
 Bilateral torus may becomeBilateral torus may become
large and meet in the mid linelarge and meet in the mid line
as shown in the picture.as shown in the picture.
 This particular condition isThis particular condition is
known as “known as “massive kissingmassive kissing
tori”.tori”.

 This radiograph showsThis radiograph shows
the radiopacity that isthe radiopacity that is
superimposed over thesuperimposed over the
roots of the mandibularroots of the mandibular
teeth.teeth.

 Occlusal view showingOcclusal view showing
bilateral mandibular tori.bilateral mandibular tori.

TREATMENTTREATMENT
 Surgical removal is required to accommodateSurgical removal is required to accommodate
complete/partial dentures.complete/partial dentures.
 May recur in presence of teeth.May recur in presence of teeth.

STAFNE DEFECTSTAFNE DEFECT
 This condition represents aThis condition represents a
focal concavity of the corticalfocal concavity of the cortical
bone on the lingual surfacebone on the lingual surface
of the mandible.of the mandible.
 In most of the cases, biopsyIn most of the cases, biopsy
has revealed histologicallyhas revealed histologically
normal salivarynormal salivary
gland,suggesting it isgland,suggesting it is
developmental defectdevelopmental defect
containing submandibularcontaining submandibular
salivary gland.salivary gland.

 AsymptomaticAsymptomatic
radiolucency below theradiolucency below the
mandibular canal in themandibular canal in the
posterior mandibleposterior mandible
between the molar teethbetween the molar teeth
and angle of theand angle of the
mandible.mandible.
 Well circumscribed by aWell circumscribed by a
sclerotic bordersclerotic border

 Anterior lingual salivaryAnterior lingual salivary
defects associated withdefects associated with
the sublingual glandthe sublingual gland
present as well definedpresent as well defined
radiolucency that mayradiolucency that may
superimpose over thesuperimpose over the
apices of the anteriorapices of the anterior
teeth.teeth.

 Here the lingual surfaceHere the lingual surface
of the mandible showingof the mandible showing
an anterior corticalan anterior cortical
defect caused bydefect caused by
sublingual gland can besublingual gland can be
appreciated.appreciated.

 CT image showing wellCT image showing well
defined concavity indefined concavity in
lingual surface.lingual surface.

TREATMENTTREATMENT
 No treatment requiredNo treatment required > if the lesion is static.> if the lesion is static.
 SurgerySurgery > if there is increase in size.> if there is increase in size.
 Prognosis: goodPrognosis: good..

MEDIAN MANDIBULAR CYSTMEDIAN MANDIBULAR CYST
 It is an extremely rare and controversialIt is an extremely rare and controversial
lesion.lesion.
 Located along the midline of theLocated along the midline of the
mandible.mandible.
 Developed due to entrapment ofDeveloped due to entrapment of
epithelium during fusion of two halvesepithelium during fusion of two halves
of the mandible.of the mandible.
 ControversyControversy::
 Mandible develops as singleMandible develops as single
bilobed proliferation ofbilobed proliferation of
mesenchyme with a centralmesenchyme with a central
isthmus in midline.isthmus in midline.
 So as the mandible developsSo as the mandible develops
the isthmus disappearsthe isthmus disappears
without any room forwithout any room for
epithelial entrapment.epithelial entrapment.

 Asymptomatic (diagnosedAsymptomatic (diagnosed
during routine radiographicduring routine radiographic
examination).examination).
 Produce expansion of theProduce expansion of the
involved cortical bone andinvolved cortical bone and
associated teeth.associated teeth.
 It is unilocular,wellIt is unilocular,well
circumscribed radiolucencycircumscribed radiolucency
may be seen in midline.may be seen in midline.
 TREATMENT :TREATMENT :
 SurgicalSurgical
enucleation.enucleation.

DEVELOPMENTAL DEFECTS OFDEVELOPMENTAL DEFECTS OF
TEMPOROMANDIBULAR JOINTTEMPOROMANDIBULAR JOINT
 Aplasia of the mandibular condyle.Aplasia of the mandibular condyle.
 Coronoid hyperplasia.Coronoid hyperplasia.
 Condylar hyperplasia.Condylar hyperplasia.
 Bifid condyle.Bifid condyle.

APLASIA OF THE MANDIBULARAPLASIA OF THE MANDIBULAR
CONDYLE.CONDYLE.
 Failure of development ofFailure of development of
mandibular condyle.mandibular condyle.
 May occurMay occur
unilaterally/bilaterally.unilaterally/bilaterally.
 If unilateral>obvious facialIf unilateral>obvious facial
asymmetry.asymmetry.
 Occlusion and mastication isOcclusion and mastication is
alteredaltered
 Shift of mandible towards theShift of mandible towards the
affected side during mouthaffected side during mouth
opening.opening.

 Associated with defective or absent external ear.Associated with defective or absent external ear.
 In bilateral cases, shift of the mandible is not seen.In bilateral cases, shift of the mandible is not seen.
 TREATEMENTTREATEMENT ::
 Severe case > Osteoplasty and correction ofSevere case > Osteoplasty and correction of
malocclusion by orthodontic appliances.malocclusion by orthodontic appliances.
 Mild > no surgical intervention required.Mild > no surgical intervention required.
 Cosmetic surgery in correcting facial deformity.Cosmetic surgery in correcting facial deformity.

CORONOID HYPERPLASIACORONOID HYPERPLASIA
 Rare developmental anomaly resulting in limitedRare developmental anomaly resulting in limited
mandibular movements.mandibular movements.
 Male: female > 5:1Male: female > 5:1
 Often seen in puberty.Often seen in puberty.
 Types :Types :
 Unilateral hyperplasia.Unilateral hyperplasia.
 Bilateral hyperplasia.Bilateral hyperplasia.

 UNILATERALUNILATERAL ::
 Enlarged Coronoid process impinging on theEnlarged Coronoid process impinging on the
posterior surface of the zygoma restricting theposterior surface of the zygoma restricting the
mandibular movements.mandibular movements.
 Mandible deviates to the affected side.Mandible deviates to the affected side.
 No pain /associated abnormality in occlusion.No pain /associated abnormality in occlusion.

 BILATERAL :BILATERAL :
 Mandibular restrictions may progressively worsenMandibular restrictions may progressively worsen
over several years during child hood and reachover several years during child hood and reach
maximum severity in late teens.maximum severity in late teens.
 TREATMENT :TREATMENT :
 Coronoidectomy/coronoidotomy > intraoralCoronoidectomy/coronoidotomy > intraoral
approach.approach.
 Post-operative physiotherapy > re-establishingPost-operative physiotherapy > re-establishing
normal function.normal function.

CONDYLAR HYPERPLASIACONDYLAR HYPERPLASIA
 Enlargement of the mandibleEnlargement of the mandible
 EtiologyEtiology :unknown.:unknown.
 Some possible etiologicalSome possible etiological
factors are :factors are :
 Local circulatoryLocal circulatory
disturbance.disturbance.
 EndocrineEndocrine
disturbance.disturbance.
 Trauma.Trauma.

 Discovered inDiscovered in
adolescence/youngadolescence/young
adults.adults.
 Facial asymmetry ,Facial asymmetry ,
prognathism , open bite ,prognathism , open bite ,
cross bite.cross bite.

 Radio graphicallyRadio graphically
there is irregularthere is irregular
enlargement of theenlargement of the
Condylar head.Condylar head.
 Some cases maySome cases may
demonstratedemonstrate
hyperplasia of thehyperplasia of the
entire ramus.entire ramus.

TREATMENTTREATMENT
 Unilateral condylectomy.Unilateral condylectomy.
 Unilateral/bilateral mandibular osteotomies.Unilateral/bilateral mandibular osteotomies.
 Patient with compensatory maxillary growth >Patient with compensatory maxillary growth >
maxillary osteotomy.maxillary osteotomy.
 Frequent orthodontic therapy.Frequent orthodontic therapy.

BIFID CONDYLEBIFID CONDYLE
 Rare developmental anomalyRare developmental anomaly
characterized by double-headedcharacterized by double-headed
mandibular condyle.mandibular condyle.
 Some may haveSome may have medial and lateralmedial and lateral
headsheads divided bydivided by anteroposterioranteroposterior
groovesgrooves..
 Some may haveSome may have anterior andanterior and
posterior headsposterior heads..
 EtiologyEtiology ::
 Anteroposterior bifid condyleAnteroposterior bifid condyle
> traumatic origin.> traumatic origin.
 MediolateralMediolateral
>traumatic,teratogenic,abnor>traumatic,teratogenic,abnor
mal musclemal muscle
attachements,persistence ofattachements,persistence of
fibrous septum in fibrousfibrous septum in fibrous
cartilage.cartilage.

 Discovered in routineDiscovered in routine
radiographs.radiographs.
 Shows bilobedShows bilobed
appearance of theappearance of the
Condylar head.Condylar head.
 AsymptomaticAsymptomatic
 Some may have “pop” orSome may have “pop” or
“click” of the TMJ“click” of the TMJ
during mouth opening.during mouth opening.

TREATMENTTREATMENT
 Asymptomatic > no treatment required.Asymptomatic > no treatment required.
 Temporomandibular therapy may be required.Temporomandibular therapy may be required.

REFERENCESREFERENCES
 Facial growth – ENLOW, 3 Edition.Facial growth – ENLOW, 3 Edition.
 Orthodontics – The art and science – BHALAJI, 1Orthodontics – The art and science – BHALAJI, 1
Edition.Edition.
 Contemporary orthodontics – WILLIAM PROFIT, 3Contemporary orthodontics – WILLIAM PROFIT, 3
Edition.Edition.
 Human embryology – INDERBIR SINGH, 5 Edition.Human embryology – INDERBIR SINGH, 5 Edition.
 Oral pathology – WILLIAM G SHAFER, 4 Edition.Oral pathology – WILLIAM G SHAFER, 4 Edition.
 Internet source –Internet source – www.google.comwww.google.com
 Oral and maxillofacial pathology – color atlas.Oral and maxillofacial pathology – color atlas.

Congenital and developmental disorders of mandible

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