OP Sheet #11 By Halah Obeidat

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v osteo genesis imperfecta :

· defect in type I collagen causes: -bone formation reduction -thin cylinder bones -excessive bone fragility -susceptibility to fracture -other symptoms : dwarfism, thin skull and bulging over the ears, defects in the bones of the ears therefore deafness, blue sclera (differential diagnosis is blue sclera), defect in cartilages collagen therefore hyper mobility and defects in heart valves

· four main types :

Type	Severity	manifestations	Dentinogenesis imperfecta
Type I	Mildest	Most common, patient lives but susceptible to fracture	No Dentinogenesis
Type II	Most severe	patient dies during birth	no teeth therefore we don’t know if Dentinogenesis imperfect is present
Type III	Less severe than type II	multiple fractures and deformities ends in the wheelchair	Dentinogenesis is present
Type IV	Type I	resembles to type I	Dentinogenesis is present

· -susceptible to bone fracture therefore care must be taken when extracting teeth (might lead to fracture of the mandible ) - class III malocclusion - susceptibility to the impaction of the first and the second molar -deformities in the respiratory system and the neck à difficult intubation àdifficult general anaesthesia

v osteopetrosis :

· -increase the density of the bone (on the account of the bone marrow and the medullary bone) - also called brittle or marble bone disease (although higher density the bone is easy to fracture) -defect in the osteoclast (they don’t do their job either during growth (bone modelling ) or during life (bone re-modelling ) )

· more info :

-pan cytopenia, pan leucopoenia, pan thrombocytopenia, anaemia -susceptible to fracture



-X ray findings: --generalized increase in bone density, no difference between cortex and medulla

--Marked radio opacity of the skull (very dense) àno sinuses, skull foramina become narrow àpressure on the nerves -motor and sensory- (pressure on the facial nerve in the foramina)

-- Dense bone àunerupted teeth, invisible roots àsusceptible to infection



v cleidocranial dysplasia :

· autosomal dominant or sporadic (new mutation, no family history )

· affects :skull ,face ,clavicle

-Skull: delay in the fontanel and suture closure therefore abnormal growth -face: reduction in the development of the middle third of the face depressed maxilla and nasal bridge normal size of the mandible (relative class III malocclusion) -chest radiograph: no clavicle (collar bone) can bring the shoulders to the mid line

Dental aspects: multiple supernumerary teeth, multiple dentigerous cysts, multiple unerupted permanent teeth (retention of primary teeth), cellular cementum defects (roots thin may be reason for uneruption)



v Achondroplasia : most common cause of dwarfism

· Difference between growth hormone defect and achondroplasia is the following :

-growth hormone defect dwarfism: generalized relative decrease in the size -achondroplasia dwarfism: normal trunk (chest and abdomen) but the limbs are short (due to a defect in endochondral ossification which happens in long bones and the base of the skull)

· autosomal dominant or sporadic mutation

· most common genetic skeletal disorder

Defect in the middle third of the face (because the base of the skull has cartilage) relative class III malocclusion



v fibro osseous lesions:

(Lesions in the bone replace the normal bone by fibrous tissue then calcification of the fibrous tissue)

-group of diseases, part of the them are benign lesions and part are benign neoplasm

· -fibrous dysplasia :

1-Monostatic: one bone 2-polystatic: multiple

· -cemento osseous dysplasia : bone and fibrous tissue ,3 types :

1- Focal: one site 2- preiapical: more than one lesion but in one area 3-florid cemento osseous dysplasia: the four quadrants (the whole jaws)

· -benign neoplasm : ossified fibroma or cemento ossified fibroma



v fibrous dysplasia :

1-monostatic: affects one bone, most common 70-80% of all cases, any type of bone such as jaws (maxilla more than mandible)

2-polyostatic: multiple bones

3-craniofacial



· CRANIOFACIAL: -painless bony swelling slowly enlarging -affects the face (multiple bones) -begins at childhood (the growth of bones), stops at the beginning of adult hood (arrest when the growth stops) -causes :

1-disturbance of the function, malocclusion, displacement of the teeth 2-swelling in the post part of the maxilla, post part of the body of the mandible 3- extension in the maxillary sinus (cant see it easily at the beginning in the frontal view better if we look from above and compare right to the left to see if there is a swelling ) 4-closed intraoral vestibule

radiograph -pathognomic features- : maxilla: looks like orange peel ,thumb print ,ground glass appearance ,bone not defined, displacement of the roots or the lamina dura not clear ,periodontal ligament doesn’t thin, mandible : superior displacement of the mandibular canal (lesion starts bellow the mandibular canal) ,ground glass appearance ,teeth displacement ,buccal and lingual expansion

· POLYOSTATIC:

-segmental bones ,on one side of the body left or right ,more common in females , -other features : Albright syndrome : Café-au-lait spots and endocrine defects (hyper thyroidism hyperparathyroidism),pernicious puberty (puberty in 4-5 year-old females) , -radiograph helps -histologically :Chinese characteristic (trabeculae of the normal bone to one direction against the stress but here they are random like chine letters surrounded by cellular fibrous connection tissue stroma ),no capsule around the lesion (not well defined ) ,woven bone, osteoblast ,and ostoeclast-like giant cells ,spherical calcifications ,in the late stage the fibrous connective tissue lessen and replaced by bone and becomes lamellar bone (at first radiolucent then as it matures becomes more dense )

-blood chemistry: (especially polyostatic fibrous dysplasia) there is an increase in the alkaline phosphatase enzyme

-etiology: why there is an increase in the growth of on bone: unknown maybe defect in: 1- a gene causes loss of the osteoblast growth 2- developmental (because it’s only in the developmental period)

Mono doesn’t turn into polyostatic

-prognosis:

1. cosmetic (cosmetic surgery delayed until growth is stopped)

2. malignancy not common unless wrongly diagnosed as cancer and radiotherapy was given to the patient therefore fibrosarcoma happens



v cemento osseous dysplasia : focal ,periapical ,florid

-periapical :

1- below the apices of the teeth

2- more than one lesion but just one area

3- painless and no swelling (accidental diagnosis),but sometimes some expansion happens

4- radiograph : radiolucent area (its a fibrous tissue ),might misdiagnose it as a periapical granuloma ,(radiolucent at first then radio opaque)

5- no root resorption(away from the cementum) therefore we can exclude ’’cementum blastoma’’ as a cause for the radiolucency

6- all teeth are vital

7- most common in :middle aged females and the black race

8- most common teeth affected : mandibular anterior teeth below the apices

-focal:

1- mostly affects Asian races

2- one lesion under the apices (same as the periapical but one lesion)





-florid:

1- excessive lesion more than three quadrant

2- a symptomatic expansion without pain

3- infection might happen and osteomilitis after extraction

4- radio opaque irregular masses four quadrant (frequently symmetrical)

5- fibrous connective tissue then calcification

6- affects the black race more than others



Benign tumour: cemento ossifying fibroma

1- histologically similar to the fibro dysplasia

2- mandibular molar and premolar region,(like the fibrous dysplasia its more common in mandible not maxilla )

3- 20-40 years of age (unlike the fibrous dysplasia which stops at adulthood)

4- radiograph difference (fibrous dysplasia ill defined but here well defined radio lucency ‘’fibrous capsule’’) easier surgery

5- radiolucent then gradual calcification radiolucent rime ,thin fibrous connective tissue capsule

Trabeculae and immature bone, cementicles: round dense calcified structures resemble cementum, more than in fibrous dysplasia,

Juvenile type affects children: differs in that it’s a rapidly growing (higher mitotic activity, higher cellularity), more aggressive and local re-occurrence rate is more; prognosis is worse, affects children less than 15 years old





Oral pathology sheet

Halah Obeidat

Correction Sheet #11 ... BY Haneen Thneabat
sheet #11 p.5 line 9 (fibrous
dysplasia is more common in maxilla than mandible, unlike the cemnto
ossifying fibroma which is common in mandibular molar&premolar
region).