3. INTRODUCTION
Cementum, or root cementum is mineralised tissue covering the
entire root surface.
According to Denton,
Cementum was first demonstrated microscopically by Frankel and Raschkow
(1835) and Retzius (1836) and has since become a part of general knowledge in
dentistry.
Cementum exists fundamentally in mammalian teeth, which fit into alveolar
sockets of alveolar bone, and functions as a tooth supporting device in concert
with the periodontal fibers and alveolar bone.
4. It is a specialised connective tissue that share some physical , chemical
and structural characteristics with compact bone.
Unlike bone, however, human cementum is avascular and non innervated.
Hard bone like tissue covering the anatomic roots of teeth
It is derived from Latin word Caementum,
which means quarried stone.
It’s a specialised mineralised tissue covering root surfaces and
occasionally small portions of crown of teeth.
7. PRE FUNCTIONAL DEVELOPMENTAL
STAGE
The prefunctional portion of cementum is formed during root development.
Since the formation of human tooth roots occurs over and extended period
of time ranging between 3.75 and 7.75 years for permanent teeth, the
prefunctional development of cementum is an extremely long-lasting
process. During this period of time, the primary distribution of the main
cementum varieties is determined for each root.
8. FUNCTIONAL DEVELOPMENTAL STAGE
It commences when the tooth is about to reach the occlusal level, is associated with
the attachment of the root to the surrounding bone and continues throughout life.
It is mainly during the functional development that adaptive and reparative
processes are carried out by the biological responsiveness of cementum, which in
turn, influences the alterations in the distribution and appearance of the cementum
varieties on the root surface with time.
9. CEMENTOGENESIS:-
The IEE(inner enamel epithelium) and OEE(outer enamel epithelium) proliferate
downwards as double layered sheet of flat epithelial cells called HERS(hertwig’s
epithelial root sheath).
This induces cells of dental follicle to differentiate into odontoblasts which secrete
organic matrix of predentin.
As odontoblast retreat inwards, they do not leave behind the odontoblastic
processes in first few layers of dentin. Hence this layer is structure less and is
called hyaline layer.
10. Subsequently, break occur in
HERS allowing newly formed
dentin to come in direct contact
with connective tissue cells of
dental follicle.
Cells derived from connective
tissue are called cementoblasts
which differentiate and form
cementum.
11. Properties
Physical properties:
Light yellow with a dull surface
Lighter in colour than dentin
Softer than dentin
Permeability:-
Cellular variety more permeable as the canaliculi in some areas are contiguous with
the dentinal tubuli.
More permeable than dentine
Decreases with age
Soft and thin cervically-readily removed by abrasion when gingival recession exposes
the root surface to the oral environment.
12. Chemical properties:
On a wet weight basis:-
Inorganic-65%
Organic -23%
Water-12%
By volume:-
Inorganic-45%
Organic -33%
Water -22%
13. THICKNESS:-
Cemental deposition continues throughout life.
Deposition most rapid in apical areas, where it compensates for tooth eruption,
which itself compensates for attrition.
Varies from 16-60 micrometer on the coronal half to 150-200 micrometer in the
apical third and furcation.
Thicker on distal than on mesial surfaces
between 11 to 70 years of age thickness increases 3 times.
14. COMPOSITION
Inorganic:-
Acellular cementum is more mineralized than cellular cementum, since there is
presence of uncalcified lacunae and uncalcified core of Sharpey's fibers in cellular
cementum.
The matrix of acellular cementum may be more completely mineralized because its
formation is a slow process which allows longer direct contact of tissue fluids.
CDJ(Cementodentinal junction) shows a zone of high mineral content and low
organic content delineated by zones of low mineral content on the dentin and
sometimes on cementum side
Principle inorganic component- hydroxyapatite (Cal0(PO4)6(OH)2) with small
amounts of amorphous calcium phosphates present
15. These crystals are thin and plate like and similar to those in bone and arranged
parallel to the long axis of collagen fibril
Length varies
Minute size of mineral crystals allows for greater capacity for adsorption of
fluoride and other elements and more readily decalcifies in the presence of acidic
conditions
Concentration of fluoride tends to be higher at the external surface, conc. of 0.9%
ash weight-
Increases with age and varies with the nutritional fluoride supply to the individual
16. Contains 0.5-0.9% Mg-occupies the place of an equal no. of Ca ions in
hydroxyapatite crystal lattice
Similar to that of bone but half of that of dentine
Mg conc. appears to be lower at the surface than in deeper layers of cementum
Contains 0.1-0.3% sulfur as a constituent of the organic matrix
Trace elements - Cu, Zn and Na
17. Organic
Collagen:-
Primarily collagen type I and III, like in bone and PDL
90% of organic matrix - type I collagen and approximately 5% - type III
It has been suggested that type I fibrils are coated by type III collagen, whereas
some studies suggests that both the collagens are co localized in the same fibril
18. Non-collagenous proteins:
Glycolipids, glycoproteins or proteoglycans
Non-collagenous proteins are similar to that of bone - bone sialoprotein and
osteopontin - both are phosphorylated and sulfated glycoproteins
Bind tightly to collagenous matrices and hydroxyapatite
Participate in mineralization process
Reveal cell attachment properties through tripeptide sequence Arg-Gly-Asp that
binds to integrins
Acellular cementum contains much more of these than cellular cementum
19. Glycoproteins - fibronectin and tenascin are more widely distributed
High molecular weight and multifunctional proteins of the extracellular matrix
Fibronectin binds cells to components of extracellular matrix
During tooth development, both are present in the basement membrane of HERS at
the time of odontoblast differentiation
Enamel related proteins - have been detected
Proteoglycans - core protein to which sulfated polysaccharides are covalently linked
- chondroitin sulfate, dermatan sulfate and hyaluronic acid
20. Osteonectin –
another glycosylated protein
Found in extracellular matrix of mineralized tissue
Close relation between osteonectin and collagen seems to exist in mineralization
process
21. Similarities with bone :-
Diseases that affect the bone, often alter cementum’s properties as well.
Paget’s disease results in hypercementosis, hypophosphatasia results in no
cementum formation, etc.
composition is similar to that of bone.
22. Differences :-
Avascular
Lack haversian canals
Non innervated
Exhibits little or no remodeling
Less readily resorbed
Differences in physiochemical or biological properties
Properties of precementum
Increased density of sharpy’s fibers(particularly in acellular cementum)
Proximity of epithelial cell rests of the root surface
24. CEMENTOCLASTS:-
Multinucleated cells
Involved with cemental resorption
These cells occurs during resorption of deciduous teeth and
when orthodontic forces are applied.
These cells not only resorb cementum, they can destroy
dentin and enamel as well thus they are also called
ODNOTOCLASTS.
25. CEMENTOIDS
Unmineralized layer of cementum on cemental
surfaces(precementum)
New layer forms as old calcifies
3 to 5 micrometer
Lined by cementoblasts
Connective tissue fibers from PDL pass between the
cementoblasts
26. ARRANGEMENT OF FIBRILS:-
The arrangement of collagen fibers in cementum can be grouped into two:-
Extrinsic fiber system:-
Consists of principle fibers(SHARPEY’S FIBERS)
Mostly arranged at right angles to cementum
Intrinsic fiber system:-
The fibers are dense and irregularly arranged within the cemental matrix
27. EXTRINSIC FIBERS (SHARPEY’S FIBERS)
Terminal portions of the principle fibers that insert into cementum and bone are
termed as Sharpey’s fibers.
Produced by cells of the dental follicle during development and later by fibroblasts
of PDL.
Oriented perpendicular to root surface
5-7 microns in diameter
These have a principal role of supporting the tooth.
Mineralized partially with unmineralized core.
28. INTRINSIC FIBERS
Produced by cementoblasts
Oriented parallel to root surface
1-2 microns in diameter
Uniformly mineralized
Mainly helps in repair
29. •CLASSIFICATION
Based on presence or absence of cells:-
Acellular cementum:-
• Appears relatively structureless-no cells.
• First formed-primary cementum
• Covers the root adjacent to the dentine more in the cervical 2/3
• Slower rate of matrix formation
• Incremental line closer
• Thickness:- 30-230 micrometer
• Precementum virtually absent
• Border with dentin not clearly demarcated
30. Cellular cementum:-
Contains cells (cementocytes)
Found in the apical and interradicular areas and
overlying the acellular cementum
Formed after acellular - secondary cementum
Fast rate of matrix formation
31. Presence of precementum
Spaces that the cementocytes occupy are called lacunae and the channels that their
processes extend along are the canaliculi
Adjacent canaliculi are often connected and the processes within them exhibit gap
junctions
32. Cementocytes are more widely dispersed and more randomly arranged
Canaliculi preferentially oriented towards PDL , they are chief source of nutrition
Once embedded cementocytes become relatively inactive:-
Their cytoplasmic/nuclear ratio decreases
Few organelles are responsible for energy production and for synthesis
Some unmineralized matrix may be seen in the perilacunar space
Border with dentine clearly demarcated
33. Based on the nature and origin of the organic matrix
Cementum derives its organic matrix from 2 sources.
Extrinsic fibers: from the inserting Sharpey's fibers of the periodontal
ligament which are perpendicular or oblique to root surface
Intrinsic fibers: from cementoblasts which run parallel to root surface
and approximately at right angles to extrinsic fibers
Mixed fiber cementum: both the above fibers are present
34. Based on presence or absence of cells and the nature and
origin of the organic matrix-Schroeder's classification
Acellular afibrillar cementum (AAC):
Contains neither cells nor extrinsic or intrinsic collagen fibers
Only mineralized ground substance
Product of cementoblasts
Found as coronal cementum
Thickness-1-15 micrometer
35. Acellular extrinsic fiber cementum (AEFC):-
Composed almost entirely of densely packed bundles of Sharpey's fibers
Product of fibroblasts and cementoblasts
They are present on cervical third of roots but may extend farther apically
Thickness-30-230μm
Cellular mixed stratified cementum (CMSC):-
Composed of extrinsic (Sharpey's) and intrinsic fibers
May contain cells
Co-product of fibroblasts and cementoblasts
They are present primarily in the apical third, apices and
in furcation areas
Thickness-100-1000 micrometer
36. Cellular intrinsic fiber cementum (CIFC):-
Contains cells, but no extrinsic collagen fibers
Formed by cementoblasts
Fills resorption lacunae
Intermediate cementum:
Poorly defined zone near cementodentinal junction of certain
teeth that appears to contain cellular remnants of Hertwig's
sheath embedded in calcified ground substance
INTERMEDIATE
CEMENTUM
37. Cementoenamel junction:-
• It is defined as the area of union of the
cementum and enamel at cervical region of
the tooth.
• Cementum overlaps enamel - 60-65%
• Edge-to-edge butt joint -30%
• Cementum and enamel fail to meet-5-10%
In this case, gingival recession may result in
accentuated sensitivity because of exposed
dentin
38. Cementodentinal junction:-
• Terminal apical area of cementum where it joins the
internal root canal dentin
• Obturating material in RCT should be at the CDJ
• No increase or decrease of width of the CDJ
occurs with age-remains relatively stable
• CDJ 2-3 um wide
• Here the fibrils intermingle between cementum and
dentin
39. Function of cementum :-
• The main function of cementum is tooth support or tooth anchorage together with the
principal fibers and alveolar bone.
• AEFC(Acellular Extrinsic Afibrilar Cementum) is therefore the most suitable
cementum for tooth support.
• The function of CIFC(Cellular Intrinsic Fiber Cementum) is more complicated.
• Extrinsic fiber-poor and -free Cellular Intrinsic Fiber Cementum) do not appear
to contribute to tooth support.
• Instead their function is adaptation, i.e. reshaping the root surface during tooth
movement and compensating for crown wear.
40. • Such Cellular Intrinsic Fiber Cementum also appears as reparative cementum
which fills resorbed root surfaces.
• Extrinsic fiber-poor and-free CIFC have the alternating lamellae, based on the
twisted plywood structure.
• In compact bone, the structure is considered to resist stresses from various
directions.
• In the same way, the alternating lamellae in CIFC may function to resist multi-
directional masticatory stresses.
• In contrast, extrinsic fiber-rich CIFC may serve as tooth support more than
adaptation.
41. • When the adaptation is required, extrinsic fiber-poor or -free CIFC forms patch-
wise on applicable portions.
• In contrast, when tooth anchorage is required, extrinsic fiber-rich CIFC or AEFC
forms.
• CMSC (Cellular Mixed Stratified Cementum) is generally thicker in molars than
in anterior teeth.
• The reason may be deduced simply; the thickness of CMSC is parallel to the
masticatory stress loaded on the tooth.
• However, it is often found that impacted or pre-functional molars, like fully
functioning molars, possess thick CMSC.
42. Age changes
Continuous deposition:-
Cementum formation continues throughout life unless disturbed by periapical or
periodontal pathology
Deposited at a linear rate
More cementum is formed apically than cervically
Cementum thickness shows variations among tooth groups and surfaces
Thick layers may form in root surface grooves and furcations of multirooted teeth
Great variations in incremental lines indicate that rate of cementum formation may
vary
43. Changes in tooth position may exert temporal and spatial variations in pressure and
tension on root and bone surfaces-
biological responsiveness of cementoblasts to these stimuli may influence the rate as
well as pattern of cementum deposition thus maintaining the tooth in proper position
and relation to adjacent teeth.
Nonfunctioning, impacted teeth appear to have thicker cementum and their
structural architecture is different .
In impacted teeth-Sharpey's fibers may be nearly completely absent in the
cementum and it is built upmainly by intrinsic fibers arranged parallel to root
surface.
44. Physiological activity of cementocytes:
No. of cells that become incorporated into cementum matrix while its formation is
proportional to the rate of cementum deposition
Cementocytes close to cementum surface may resemble cementoblasts but the amount
of cytoplasm is reduced and they contain less endoplasmic reticulum and fewer
mitochondria.
Most well developed cell processes point towards root surface, it indicate that
exchange of metabolites through cellular intrinsic fiber cementum is limited.
In deeper layers of CIFC, more advanced nuclear and cytoplasmic changes may occur
or lacunae may appear empty, it could be due to starvation or consequence of age.
45. Cementum reactions to physiological tooth movement and occlusal
forces:
Presence of cementum on impacted teeth indicates that occlusal forces are not
necessary to stimulate cementum deposition
In posterior teeth, cementum is markedly thicker on the distal than on the mesial
root surface - indicating relationship to mesial drift
Cementum like bone is dynamically responsive and its growth may be stimulated by
tensional forces
Cementum thicker in areas exposed to tensional forces
46. Resorption and repair
Types of resorption:-
Physiological root resorption:- normal phenomenon of deciduous teeth during tooth
shedding
Causes for resorption of permanent teeth:-
pathological like infectious, systemic diseases like calcium deficiency,
hypothyroidism, hereditary fibrous osteodystrophy and Paget's disease or tumors
nonpathological like trauma (mechanical, chemical or thermal) or sustained
overcompression of the PDL
Idiopathic
47. Root resorption classified according to location as:-
Internal
External
• According to degree of persistence:-
• Transient
• Progressive
• Root surface more resistant to resorption than bone
• No. of teeth resorbed, and severity of resorption are markedly increased by
orthodontic treatment.
• Appears microscopically as bay like concavities in the root surface
48. • Multinucleated giant cells and large mononuclear macrophages are generally found
adjacent to cementum.
• May extend into underlying dentin
• Not necessarily continuous, may alternate with periods of repair and deposition of
new cementum, new cementum is demarcated from the root by a deeply staining
irregular line - reversal line
49. Repair:-
Following detachment of odontoclasts from the root surface, cementogenic cells repopulate
the Howship's lacunae and attach the initial repair matrix to a thin decalcified layer of residual
and exposed collagen fibrils
• Basophilic and electron dense reversal line forms at the fibrillar junction
• Deposited repair matrix resembles cellular intrinsic fiber cementum
• Cementum repair require a viable connective tissue
• Can occur in devitalized and in vital teeth
51. Concrescence:-
• Form of fusion which occurs after root formation
• Teeth are united by cementum
• Thought to arise as a result of traumatic injury or crowding of teeth with resorption
of interdental bone, so that 2 roots are in approximate contact and become fused by
deposition of cementum.
• May occur before or after tooth eruption
• Diagnosed radiographically
• Extraction of one may result in the extraction of the other
52. Ectopic enamel :-
Presence of enamel in unusual locations, mainly tooth root
Enamel pearl:-
Hemispheric structures consisting entirely of enamel or contain
underlying dentin and pulp tissue
Project from surface of root
Thought to arise from localized bulging of odontoblastic layer.
The Bulge may provide prolonged contact between HERS and
developing dentin, thus triggering the induction of enamel
formation.
53. More common in maxillary molars
Majorly occur in furcation area or CEJ
Prevents normal periodontal attachment with connective tissue and a
hemidesmosomal junction probably exists
Less resistant to breakdown, once separation exists there is a rapid loss of attachment
Leads to plaque retention and inadequate cleansing
54. Cervical enamel projections:-
Represent dipping of enamel from CEJ toward the bifurcation.
More in mandibular molars on the buccal surface.
Correlated positively to localized loss of periodontal attachment with furcation
involvement.
Have been associated with development of inflammatory cysts.
Histopathologically identical to periapical cysts.
Develop along buccal surface over the bifurcation called buccal bifurcation cysts
55. Good oral hygiene is required to prevent localized
loss of periodontal support.
Sometimes removal of the enamel is advised to
achieve a more durable periodontal attachment.
56. Hypercementosis:-
Nonneoplastic deposition of excessive cementum that is continuous with the normal
radicular cementum
Radiographically:-
Thickening or blunting of the root, surrounded by radiolucent PDL space and intact
adjacent lamina dura.
Also appears in form of spike-like excrescences called cemental spikes created by
either coalescence of cementicles to the root or calcification of PDL fibers
57. May be isolated, may
involve multiple teeth or
may appear as a generalized
process.
Premolar teeth involved
most frequently .
Occurs predominantly in
adulthood and frequency
increases with age.
58. Factors associated
Local factors
Abnormal occlusal trauma
Adjacent inflammation
Unopposed teeth (eg. Impacted, embedded, without antagonist)
Systemic factors
Acromegaly and pituitary gigantism
Arthritis
Calcinosis
Paget's disease of bone
Rheumatic fever
Thyroid goiter
59. Histopathologically:-
Periphery of root demonstrates deposition of an excessive amount of cementum over
the original layer of primary cementum.
Excessive cementum may be hypocellular or exhibit areas of cellular cementum that
resemble bone(osteocementum).
Often arranged in concentric layers.
May be applied over the entire root or be limited to the apical portion.
Use of polarized light clearly separates dentin and cementum.
Treatment:- Require no treatment, but in certain cases extraction has been
difficult where sectioning of the tooth may be required.
60. Ankylosis:-
Cessation of continued eruption.
Anatomic fusion of tooth cementum or dentin with alveolar bone.
Other terms:- Infraocclusion, secondary retention, submergence, reimpaction and
reinclusion.
Pathogenesis is unknown and may be secondary to disturbances from:-
Changes in local metabolism
Trauma
Injury
Chemical or thermal irritation
Local failure of bone growth
Abnormal pressure from the tongue
61. Periodontal ligament might act as a barrier that prevents osteoblasts from applying
bone directly onto cementum, ankylosis could arise from a variety of factors that
result in a deficiency of this barrier, it could be due to trauma or genetically
decreased periodontal ligament gap.
Other theories point to a disturbance between normal root resorption and hard tissue
repair.
Several investigators believe genetic predisposition has a significant influence and
point to monozygotic twins who demonstrate strikingly similar patterns of ankylosis
Clinical and radiographic features:-
May occur at any age, mainly 7-18 years
Most commonly involved tooth is mandibular primary 1st molar
62. Occlusal plane is below that of adjacent dentition
Sharp solid sound on percussion when more than 20% of the root is fused to bone.
Radiographically-absence of periodontal ligament space, but the area of fusion is
often in the bifurcation and interradicular root surface making radiographic
detection difficult.
Ankylosed teeth that are allowed to remain in position causes occlusal and
periodontal problems to the adjacent teeth that are incline towards it.
Opposing tooth exhibits overeruption.
It also leads to impaction of the underlying permanent tooth.
63. Treatment:-
Fail to respond to orthodontic treatment
When an underlying permanent successor is present, extraction should not be
performed until it is obvious that exfoliation is not proceeding normally, or adverse
occlusal changes are developing.
In permanent teeth or primary teeth without underlying successors a prosthetic
buildup can be placed to augment the occlusal height.
Luxation of affected permanent teeth may be attempted with extraction forceps to
break the ankylosis.
Subsequent inflammatory reaction may result in the formation of a new fibrous
ligament in the area of previous fusion.
Reevaluation in 6 months is mandatory.
64. Abrasion:-
Pathologic wearing away of tooth
substance through some abnormal
mechanical process.
Usually occurs on exposed root surfaces
Robinson stated that the most common
cause of abrasion is the use of an abrasive
dentifrice
65. Modern dentifrices are not sufficiently abrasive and can cause remarkable wear of
cementum and dentin if toothbrush carrying it is injudiciously used, particularly in
horizontal direction
V-shaped or wedge shaped ditch on root side of CEJ in teeth with some gingival
recession.
Angle formed in lesion is sharp.
Dentin appears to be highly polished.
Improper use of dental floss and toothpicks may produce lesions on proximal
exposed root surface.
66. Root caries
Soft progressive lesion that is found anywhere on the root surface that has lost
connective tissue attachment and is exposed to the oral environment.
Occurs on dentitions of older age group people with significant gingival recession and
exposed root surfaces.
It was earlier referred to as caries of cementum.
It initiates on mineralized cementum and dentin surfaces which have greater organic
component than enamel.
Occurs frequently on buccal and lingual surfaces of roots.
67. Dental plaque and microbial invasion are an essential part of the cause and
progression of the lesion.
Organisms - filamentous
Microorganisms appear to invade the cementum either along Sharpey's fibers or
between bundles of fibers.
Since cementum is formed in concentric layers and presents a lamellated
appearance, microorganisms tend to spread laterally between various layers.
After decalcification of cementum, softening and destruction of the remaining
matrix takes place.
68. Later invasion of microorganisms into dentinal tubules - matrix destruction-pulpal
involvement.
As there are less dentinal tubules per unit area in root than in crown, there is
difference in rate of caries progression and amount of dentinal sclerosis present.
Most frequently affected teeth are mandibular molars, next the mandibular
premolars and then the maxillary cuspids, interproximal areas were mostly affected
in the maxillary arch and the buccal surface in mandibular arch.
69. Cervical root resorption:-
Development of large root resorption defect in cervical region is
most likely triggered by inflammatory processes in adjacent
connective tissue.
Such resorption generally has an undermining character.
Tooth is resorbed after the alveolar bone.
Immunity to resorption has been linked to presence of an
uncalcified, vital layer of precementum on root surface.
Another explanation could be because cementum is avascular
Odontoclasts take their origin from bone marrow and cannot
attack the root surface as fast as the osteoclasts reach the bone
surface.
70. Benign cementoblastoma (True Cementoma):-
Probably a true neoplasm of functional cementoblasts which form a large mass of
cementum or cementum like tissue on the tooth root.
Clinical features:-
Frequently, under age of 25 years
No significant sex predilections
Mandibular first permanent molar is most frequently affected tooth.
Other teeth involved are mandibular second and third molars, bicuspids, maxillary
bicuspids and first, second and third molars.
71.
72. Associated tooth is vital unless coincidentally involved
Lesion is slow growing and may cause expansion of cortical plates of bone, but is
usually otherwise asymptomatic.
Radiographic features:-
Tumor mass is attached to tooth root
Appears as a well circumscribed dense radioopaque mass often surrounded by a
thin, uniform radiolucent line.
Outline of the affected root is generally obliterated because of resorption of root and
fusion of the mass to the tooth.
73. Histologic features:
Main bulk of tumor mass is composed of sheets of cementum like tissue, sometimes
resembling secondary cellular cementum, but other times being deposited in a
globular pattern resembling giant cementicles.
Reversal lines scattered throughout this calcified tissue are quite prevalent.
Variable soft-tissue component consisting of fibrillar, vascular & cellular elements.
Many cemental trabeculae in areas of activity are bordered by layers of cementoblast.
Away from these trabecular surfaces, cementoclasts may be evident
74. Frequently microscopically indistinguishable from the benign osteoblastoma or
giant osteoid osteoma
Some areas are so cellularly active that they bear strong resemblance to
osteosarcoma
Periphery of tumor generally shows a soft tissue cellular layer resembling capsule -
here cemental trabeculae are almost arranged at right angles
Treatment and prognosis:-
Because of tendency for expansion of the jaw, it is believed that extraction of the
tooth is justified despite the fact, that the pulp is vital - recurrence is rare.
Distinguish from severe hypercementosis or chronic focal sclerosing osteomyelitis
(ie., condensing osteitis) both of which may superficially resemble.
75. Periapical cemental dysplasia
Other names:-
Cementoma
Periapical Osteofibroma
Osteofibrosis
Cementifying fibroma
Localized fibro-osteoma
Cementoblastoma
Periapical fibrous Dysplasia.
Etiology
Unknown
Suggested to occur as a result of mild chronic trauma or traumatogenic occlusion
76. Clinical feature:
Age – commonly at 2nd decade of life.
More common in females and more often in mandible.
Lesion occurs in PDL around the apex of the tooth usually mandibular incisor
Almost asymptomatic, when localized near the mental foramen appear to impinge
mental nerve and produce pain, paresthesia and even anaesthesia.
77. Histologic and radiographic features:-
The lesion progress through three distinct stages:-
Osteolytic phase:- Periapical bone is replaced by a fibrous connective tissue,
there is fibroblastic proliferation that may contain small foci of osteoid formation -
Radiographically a radiolucent area
Cementoblastic phase: Islands and spicules of cementum like matrix form
within the connective tissue- Radiographically calcification in radiolucent area
Mature stage: The lesion is predominantly composed of irregular cementum like
material, which is densely mineralized. Radiographically it has a well defined
radioopacity that is usually bordered by a thin radiolucent line or band.
78. Treatment and Prognosis :-
Periodic observation, since its harmless, under no circumstances should one extract
the tooth or institute endodontic procedures or otherwise disturb the tooth unless,
for reasons not related to the condition
79. CENTRAL CEMENTIFYING FIBROMA
• Neoplasm of the bone
• There is remarkable similarities in clinical and histological features between
central cementifying fibroma and central ossifying fibroma
• These two are separate benign tumors, identical in nature except for the cell
undergoing proliferation, the osteoblast with bone formation and cementoblast
with cementum formation.
80. Clinical features:-
Common in young and middle-aged adults, avg-35 yrs
• Females: males = 2:1
• Marked predilection for mandible
• Generally asymptomatic until growth produces noticeable swelling and mild
deformity
• Displacement of teeth may be an early feature
• Relatively slow growing tumor, the cortical plates of bone and overlying mucosa or
skin are intact
81. Radiographic features:-
variable depending upon stage of development
well circumscribed, demarcated from surrounding bone
early stages- appears radiolucent
as tumor matures, there is an increase in calcification and radiolucent areas
becomes flecked with opacities until it appears as an extremely radioopaque mass
displacement of adjacent tooth is common
have a centrifugal growth pattern, it grows by expansion in all directions
when it reaches the inferior border of mandible, produces an expansion that in
continuity with outline of tumor mass
82. Histologic features:
Composed of many delicate interlacing collagen fibers interspersed by large
numbers of active, proliferating fibroblasts or cementoblasts.
Many small foci of basophilic masses of cementum-like tissue that are irregularly
round, ovoid or slightly elongated.
As lesion matures, islands increase in no. they enlarge and coalesce.
Treatment and prognosis:-
Should be excised conservatively
Recurrence is rare
83.
84. Focal cementoosseous dysplasia:-
• Benign lesion, occupies a portion of the spectrum
between periapical and florid cemento osseous dysplasia
• Posterior mandible is predominant site
• Asymptomatic and detected only on radiographic
examination
• Smaller than 1.5 cm in diameter
• May occur on dentulous and edentulous areas
85. •Histologic feature:-
• Tissue consists of fragments of cellular mesenchymal tissue composed of spindle
shaped fibroblasts and collagen fibers with numerous Small blood vessels.
• Trabeculae of woven bone and cementum like material are interspersed throughout
the fibrous framework.
87. •Cleidocranial dysplasia
• Characterized by abnormalities of the skull, teeth jaws and shoulder girdle and
occasionally stunting of the long bones
• Oral findings:- prolonged retention of deciduous teeth and subsequently delay
in eruption of the succedaneous teeth
Roots of the teeth are often short and thinner than usual and may be deformed
• Surprising and unexplained feature was the absence of cellular cementum on the
erupted teeth in both dentition, with no increased thickening of primary acellular
cementum
88.
89. •Hypophasphatasia:-
• Hereditary disease due to deficiency of enzyme alkaline
phosphatase in serum or tissues and excretion of
phosphoethanolamine in urine
• Earliest manifestation - may be loosening and premature loss
of deciduous teeth, chiefly incisors
90. • Teeth present a unique appearance characterized by the absence of cementum,
presumably, as a result of cementogenesis, so that there is no sound functional
attachment of the tooth to bone by PDL accounts for spontaneous exfoliation of
deciduous teeth. Occasionally a foci of poorly formed cementum may be found on
some teeth.
91. Hyperpituitarism:-
Increase in no. of granules in acidophilic cells or an adenoma of anterior lobe of the
pituitary gland – gigantism or acromegaly
Enlargement of jaws- mainly mandible, macroglossia, anterior open bite
Root of posterior teeth enlarge as result of hypercementosis - may be the result of
functional and structural demands on teeth, instead of a secondary hormonal effect
Supraeruption of the posterior teeth may occur in an attempt to compensate for the
growth of the mandible
92. Hypothyroidism:-
• Cretinism in infants or myxedema in adults
• Decreased levels of thyroid hormone
Clinical features:–
• lethargy, dry coarse skin, swelling of face and extremities, husky voice,
constipation, weakness and fatigue, bradycardia, hypothermia
Oral findings:–
• enlarged tongue, teeth may fail to erupt if developed during childhood, in adults
external resorption of roots may occur
93. • Hyperparathyroidism:-
Excess production of PTH, usually occurs in response to
low levels of serum calcium
• Clinical features:-
Stones - renal calculi, metastatic calcifications involving
other soft tissues
• Bones - subperiosteal resorption of phalanges of index
and middle fingers, loss of lamina dura around teeth and
root resorption, brown tumor which is dark reddish-brown
color of tissue specimen because of abundant hemorrhage
and hemosiderin deposition in the tumor- ground glass
appearance radiographically
• Abdominal groans - due to duodenal ulcers
94. Paget's disease of bone:-
• Multicentric benign tumor of osteoclasts has been suggested
• Characteristic deformities of skull, jaw, back, pelvis and legs
• Facial appearance - leontiasis ossea
• Ground glass change in alveolar bones
• Loss of lamina dura and root resorption
• Generalized hypercementosis sometimes
95. REFERENCES:-
S.N Bhaskar, G.S Kumar :- Orban’s: Oral histology and Embryology
B.K.B Berkowitz, G.R. Holland, B.J Moxham :- Oral anatomy, Embryology and Histology
D.D Bosshardt and K.A Selvig:- Dental cementum: the dynamic tissue covering of the
root- PERIO 2000
Newman Takei and Klokkevold Carranza:- Clinical Periodonotology
Lindhe J:- Clinical Periodontology and Implant Dentistry
96. Shafer, Hine and Levy:– Oral Pathology
Neville, Damm, Allen, Bouquot :- Oral and Maxillofacial Pathology
Tsuneyuki Yamamoto, Tomoka Hasegawa, Tomomoaya Yamamoto, Hiromi Hongo,
Norio Amizuka:– Histology of Human Cementum: its structure, function and
development.
Kowsalya S, Anil Kumar K , Jaideep Mahendra, Ambalavanan N:- A review
on Cementum- The Dynamic Anchor of The Periodontium.
