Patho Buccal 2 (1).pdf

Cours 2: Maladies osseuses Ostéopétrose : 3 types, rare HEREDITARY metabolic disease Caracterized by bone densification; caused by defect in OSTEOCLASTE functioning or differentiation (bone does NOT resorb) Many genes identified (among some that code for RANK, RANK-L, OPG); cau...

Cours 2: Maladies osseuses Ostéopétrose : 3 types, rare HEREDITARY metabolic disease Caracterized by bone densification; caused by defect in OSTEOCLASTE functioning or differentiation (bone does NOT resorb) Many genes identified (among some that code for RANK, RANK-L, OPG); causing disorder in the production of acids in “lacunes d’Howship” & inadequate molecular exchanges Histopathology: obliteration of medullar cavities by dense compact bone; we may either see unchanged/increase in osteoclasts or decrease. If unchanged or increased, absence of “lacunes d’Howship”. If decreased (almost absent), RANK & RANK-L anomaly. TX: bone marrow allograft (alogrèffe moelle osseuse) for “maligne infantile” only IF adequate genetic DX & absence of neurological effect ; symptomatic treatement for all other forms. Transfusions are done to treat for anemia, and osteomyelitis should be treated Pronostic: lethal for “infantile”; other forms have better outlook Ostéopétrose maligne infantile: ▪ DX during birth/childhood ▪ Description: lack of white and red blood cells, as well as platelets (plaquettes); obliteration of medullar cavities & replacement of bone marrow (moelle osseuse) by compact bone (os compact), sclerosis of cranial foramens (which can cause nervous compressions) ▪ Results in: anemia, increased risk of infections and bleeding; increased fragility & fractures + difficulty to visualize roots + decreased vascularization (mandibule –> very high risk  ostéomyélite); facial paralysis, blindness and deafness (paralysie facial, cécité et surdité) Ostéopétrose intermédiaire: ▪ Most symptoms shown around 10 yo, bone marrow stays fonctionnal (generally) ▪ Moderate anemia & extramedullary hematopoiesis (hématopoïèse extra-médullaire) Ostéopétrose adulte: ▪ 40% asymptomatic ▪ Description: cranial nerve compression, bone fractures, ostéomyélite mandibulaire ▪ Gene manifests itself on chromosome 1 Dysplasie cléido-crânienne : Gene RUNX2/Cbfa1 on 6p21 chromosome (6) The gene controls osteoblast differentiation from mesenchymal cells during membranous ossification; & chondrocyte maturation during endochondral ossification RUNX2 seems to play a role in odontoblast differentiation, formation of enamel and proliferation of dental lamina Description: rare condition with NO predominance, autosomal dominant with complete penetrance, 40% cases have NO family history, normal intelligence Clinical symptoms: pt have clavicular, cephalic, and dental anomalies; hypoplasia of clavicula is typical and usually partial, but BILATERAL: 10% have complete aplasia; pt have small size and certain characteristics: large skull, hypertelorism, pronounced frontal bossing, widened and depressed base of the nose  Buccal anomalies: palatine vault is high, narrow and hollowed out (voûte palatin haute, étroite et creusée); high prevalence of palatin fissures, maxillary hypoplasia and relative mandibular prognathism Dental anomalies: extended retention of primary teeth, and delayed eruption of permanent teeth; MANY supernumerary teeth (dents surnuméraire) up to 50 teeth! Causes dentigerous cysts (kystes dentifère) TX: restore pt esthetic & function (but, in most cases asymptomatic). Extraction of primary teeth + Maladie de Paget: Nom alternative: ostéite déformante Description: INCREASED bone remodeling (cause hypertrophie et désorganisation os COMPLÈTE), deformities & microfractures causes pain, 2nd most COMMON metabolic bone disease (osteoporosis is #1) Démographie: England, West Europe, britannique émigrés, 60 yo and + (frequency INCREASES with age), slightly more common in MEN. Étiologie: unknown but related to ENVIRONNEMENTAL and GENETIC factors which cause osteoclast (& potentially osteoblast) function deregulation. 10-20% have POSITIVE family history, POLYOSTIQUE > monostique Sequestome 1 (SQSTM1): most common MUTATION, codes for p62 (activates NF-κB which INCREASES osteoclast activity), 20-50% of those with positive family HISTORY, 5- 20% in other cases, most SEVERE form & YOUNG age Osteoclast precursors have VERY high AFFINITY for factors that STIMULATES bone RESORPTION: 1,25(OH)2D3 + RANKL + interleukine-6 (IL-6) Pathologie: deregulation in FORMATION & bone RESORPTION process. o Phase lytique: bone is resorbed (by numerous large osteoclasts with many  o nuclei) + bone remodeling is VERY FAST o Phase mixte: resorption process accompanied by excessive bone deposition by osteoblasts. The bone formed is ANORMAL. The collagen is ANARCHIQUE. Bone vasculisation is INCREASED. o Phase sclérose: Bone deposition is PREDOMINANT. Bone is BAD quality and DISORGANIZEED. “Mosaique à l’os”. Bone is WEAK and vascularisation is REDUCED. Clinical Symptoms: o Os affectés (most to least): iliac bone, lumbar vertebrae, femur, tibia and skull (crâne = signe xpeau) o Atteinte mâchoires = 17% (more MAXILLARY), enlargement of the middle third of the face (“tete de lion”), o Asymptomatic in MORE than 50% of patients, results in INCREASE of alkaline phosphates o Progressive INCREASE of skull circumference (densification) –> OBLITERATION of cranial foramens and nervous compressions (causes deafness and blindness) o Main symptoms: severe pain and DEFORMATIONS of long bones! Cavité buccal: o Symmetric ENLARGEMENT of alveolar ridge, lowering of the palatine vault (voute palatin) o Enlargement of alveolar ridge causes progressive INADAPTATION of denture (protheses dentaires) & DIASTEMA formation RX: o Loss of DIFFERENTIATION between SPONGY bone and CORTICAL bone; bone HYPERTROPHIA, osteolysis, generalized HYPERCEMENTOSIS o Phase lytique (diminution density): OSTEOPOROSIS (osteoporose circonscrite) + radioclaire au crane  o Phase osteoblastique (augmentation density): CORTICO-MEDULLARY dedifferentiation + THICKENING outer skull; bone sclerosis « aspect de ouate de coton », generalized HYPERCEMENTOSIS and loss of lamina dura Laboratoire: o Bilan phosphocalcique NORMAL usually o Pyridinolines, Déoxypyridinolines and N-télopeptides (allows to measure remodelling) = biological markers Histopathologie o Areas of OSTEOLYSIS adjacent to bone APPOSITION o INCREASED osteoblasts, lamellar bone is ABNORMAL (large fibres of collagen, partly calcified and misoriented). REPLACES spongy bone of the epiphyses, the cortical bone and fills the medullary cavity. Osteoclasts ++ VOLUME and nuclei (50-100!) o Bone TRABECULAE have a MOSAIC appearance, and are demarcated by reversal lines (lignes basophiles inversées) o Active phases: bone marrow tissue (tissue medullaire) very VASCULARIZED (causes bleeding during extraction) o Advanced stages: acellular spherical masses FUSE to form large areas of sclerotic bone (causes osteomyelitis during extraction) TX: normalise biological markers, BIPHOSPHONATES (only if ACTIVE and risk of complications), adjustment or redo dentures, difficulty during extraction o Note: in severe cases, HIGH risk of osteomyelitis (ostéomyélite) during CHX Pronostic: o Low fatality o UNLIKELY risk of sarcoma: ▪ Osteosarcoma: 1%, mostly in long bones ▪ Fibrosarcoma: even lower risk ▪ Certain cases, large cell bone tumor may happen  ▪ Increase in vascularization during active phases MAY cause congestive HEART failure (neurological symptoms are also possible) Chérubisme: HERIDITARY disease, BILATERAL and symmetric Autosomal dominant, variable expressivity and HIGH penetrance Gene: SH3BP2 on chromosome 4 (4p16) Modifies osteoblastic and osteoclastic activity Touches MAXILARIES (rarely anything else) Clinical symptoms: o Starts during childhood between 2-5 yo, progresses until stabilizes at PUBERTY, appearance becomes almost normal at 30 yo o Causes maxillaries expansion (+++ common in MANDIBULE, tuberosities +++ in max) and certain aesthetic changes o Predilection site: ANGLE of mandibula and ascending RAMUS o BILATERAL and symmetric: bilateral non-painful swelling (tumefaction) that swells cheeks and stretches face (eyes downward) o “cherubin vers ciel”; speech, chewing and swallowing disorders Dental anomalies: o Agenesis of second and third MOLARS inf, absence or mvmt of primary & permanent, resorption or PREMATURE loss of primary and LATE eruption of permanent RX: o Radioclear, MULTILOCULAR, bilateral and symmetric implicating ANGLE of mandibule -> causes expansion, thinning and perforation of CORTICALES. o Advanced stages: GRANULAR aspect (“verre depoli”) o Teeth that are in lesioned sites may be impacted (incluse) or moved  Histologie : looks like granulome centrale à cellule géant (GCCG), but LESS dense stroma. Eosinophilic tissue MAY surround small blood vessels. Advanced lesions have + DENSE fibrous tissue, a LIMITED nbr of giant cells and newly formed bone trabeculae. TX : DO NOT TREAT with radiotherapy. CHX not RECOMMENDED (due to regression; only consider if very advanced). Extraction of included teeth, ortho and dentures are possible solutions. Hyperparathyroidie (HPT): Can be primary, secondary or tertiary. Primary: 85% caused by parathyroid ADENOMA. Hyperplasia or rare carcinoma of parathyroid gland cause 10%. Seen in syndromic cases, such as NEM-1/2. Caused by INCREASED serum PTH level + HYPERCALCAEMIA. Symptoms include: painful bones, renal stones, abdominal groans and psychic moans. Secondary: chronic renal failure is most COMMON cause. Vitamin D deficiency and PTH resistance are other possible causes. Decrease of phosphate excretion, hyperphosphatemia and hypocalcaemia. Stimulates secretion of PTH -> stimulates bone resorption AND increases serum CALCIUM level. Also reduces Vit D production -> reduces calcium absorption and leads to hypocalcaemia RX: o OSTEOPOROSIS. Loss of cortical definition surrounding max sinus and mand canal. Loss of lamina dura. “Verre depoli”. Brown tumors (large cell osteolytic lesion) are sometimes observed. Laboratoire: bilan sanguine of primary -> hypercalcaemia, hypophosphatemia, INCREASED serum PTH level, increased urinary phosphate  Histopathologie: REDUCTION of bone trabeculae count, INCREASED count of osteoclasts. Brown tumors ressembles GCCG, and is INDISTINGUISHABLE histologically; therefore, parathyroid gland function may be investigated. TX: o Primary hyperparathyroidism treated by CHX excision of adenoma or gland. o Secondary treated by organ transplant (restores calcitriol function and normalizes phosphate/calcium level). o Parathyroidectomy recommended if pt does NOT respond to TX Maladies osseuses d’origine diverses Ostéosclérose idiopathique: Region with dense bone, NOT associated with infection/dysplastic/neoplastic or systematic condition DX dif: ostéite condensante (has INFLAMMATORY process) Clinic: prevalence is 5%; 90% in posterior region of mandibula. No predilection for gender. Completely ASYMPTOMATIC, causes no expansion of cortical bone and tooth remains ALIVE RX: o Radio-opaque, usually alone o Well defined & does NOT have radioclaire ligne around it o The possible differential diagnosis are: ostéite condensante, dysplasia cémento- osseuse périapicale, cémentoblastome, ostéome  TX: dx from x-ray is sufficient Ostéite condensante (sclérosante): Region with dense bone, from INFLAMMATORY process (eg. Maladie pulpaire, lesion apical, atteinte paro) Prevalence: kids or young adults. Touches mostly premolar/molar of MANDIBULA and does NOT cause any bone expansion RX: o Radio-opaque at apex, no radioclaire contour o Affected tooth usually manifests a deep carious lesion, defective restauration, thickening of periodontal ligament or periapical inflammation DX: in cases of doubt, vitality test allows to differentiate with idiopathic osteosclerosis TX: elimination of what causes inflammation (eg. Extraction or endodontic treatment) Défaut ostéoporotique localisé de la spongieuse osseuse : Caused by hematopoietic tissue collection, resulting in radiotranslucent region Prevalence: 75% adult WOMEN. Touches posterior of MANDIBULA, especially edentulous areas Clinic: always ASYMPTOMATIC RX: radiotranslucent region that is POORLY defined, with fine bone trabeculae. NO signs of bone expansion or sclerotic reaction in periphery Histopathologie: NORMAL collection of hematopoietic cells and bone trabeculae TX: x-ray is non diagnostical; a biopsy must be done to exclude other pathological condition Granulome centrale à cellules géantes (GCCG) : Benign intraosseous lesion  Presents certain mutations : TRPV4, KRAS, FGFR1 Prevalence: WOMEN 3 :1 (3 times more likely), all ages but 60% of cases are seen in UNDER 30. Mandibula, especially anterior to 1st permanent molar, is the predilection site Careful: if BILATERAL, investigate for chérubisme! Clinical: 2 types o Non-aggressive: ▪ SLOW growth and LOW recurrence rate ▪ Mostly ASYMPTOMATIC o Aggressive: ▪ More in YOUNG pt ▪ FAST growth and HIGH recurrence rate ▪ LARGE size when discovered ▪ Symptoms: pain, paresthesia, expansion/perforation of bone cortices, extension into soft tissues, ulceration of the surface mucosa and dental resorptions RX: radioclaire lesion, uni/multilocular with SEPTAS. Granular apparence. Well defined, but NON-corticated. In maxillary, lesions are MAL defined and imitates a malignant process Histopathologie: o Cellular proliferation in highly VASCULARIZED stroma o Population of fusiform/oval MONONUCLEAR cells and population of MULTINUCLEATED giant cells of OSTEOCLASTIC nature o Number, form, and dimension vary CONSIDERABLY from case to case  o Stroma demonstrates areas of HEMORHAGE and EXTRAVASION of red blood cells, hemosiderin deposits, and trabeculae of osteoid or immature bone TX: CHX -> conservative IF non-aggressive; aggressive requires larger excision with extraction of teeth present in lesioned site Lésions fibro-osseuses bénignes: Normal bone replaced by COLLAGEN fibers ; can resemble to immature bone (ostéide), bone or tissue similar to dental cement Developmental, reactional (dysplasique) & neoplastic conditions Dysplasie fibreuse: “Défaut développement” GNAS gene, on chromosome #20 Severity depends on when lesion happens Two forms: MONOstotique vs POLYostotique Can present cutaneous and endocrinal symptoms Dysplasie fibreuse MONOstotique: o +++ frequent, 80-85% cases o No predilection by sex ; maxillaries = predilection site o Touches: ribs (côtes), femur, tibia and maxillaries Dysplasie fibreuse POLYostotique : o 2+ bones (up to 75% of bones) ; often only ONE HALF of body o Predilection: WOMEN o Clinical: symptoms related to long bones (pain, deformities, difference of length, fractures)  o Cranio-facial injury: facial asymmetry, vision issues, loss of hearing, nasal congestion, obstruction of upper lungs o Skull injury: neurological symptoms o 2 syndromes: Jaffe-Lichtenstein & McCune-Albright Jaffe-Lichtenstein syndrome (polyostotique): o Cutaneous pigmentation (taches café au lait) ; affects TRUNK (tronc) and THIGHS unilateraly, but can also touch buccal mucous McCune-Albright syndrome (polyostotique): o Cutaneous pigmentation (taches café au lait) + ENDROCINAL disorders (early puberty in girls, hyperthyroidism, diabetes or pituitary adenoma) o Dental anomalies: oligodontia, tooth movements, taurodontism, enamel disorders and prolonged PERSISTANCE of primaries Cranio-facial area: MONOSTOTIQUE form is most common, with predilection at POSTERIOR of MAXILLARY ; symptoms start at childhood or teenager ; slow EXPANSION (buccal + lingual) of arcade with movement of teeth ; teeth remain VITAL RX: o Initial: lesions begin radio-claire (similar to cyst) and become mix o Final: bone DENSIFICATION (radio-opaque), “pelure d’orange ou verre dépoli” (EXAM !!), poorly defined contour o Cortical EXPANSION (without breach), loss of lamina dura, OBLITERATION of sinus o May move mandibular canal upwards: key tale SIGN of fibrous dysplasia  Histopathologie: o well-VASCULARIZED connective tissue stroma w/ woven bone trabeculae (CHINESE characters), variable # of osteoCLASTS o NO caspule (not surrounded by osteoblasts), fuses with regular bone o Trabaculae: irregular, curvilinear, imature TX: o Growth is MAXIMAL in childhood and teenage years, STABILIZES with bone MATURITY o Conservative TX, ideally DELAY until END of growth o If deformities are minon = no TX o If major = “ostéotomies modelantes” AFTER growth end ; if in active phase, 20- 50% risk of recurrence o May cause: hemorrhagic cystic lesions (kyste osseux anévrysmal) or GCCG. Risk of sarcoma transformation is VERY low (seen in radiotherapy) o EXAM!!! NEVER EVER DO RADIOTHERAPY o DX dif: ostéite et ostéomyélite (cortical breach + sequestres) Dysplasies cémento-osseuses: MOST frequent LFOB (lesions fibro-osseuses benign) of maxillaries ABNORMAL et DISORGANIZED bone production with NO risk of malignant transformation DX dif: epithelial dysplasia (risk MALIGNANCY) 3 conditions: periapical, focal, familial floride o Periapical: ▪ +++ frequency in BLACK WOMEN, 30-50 yo (70% of cases) ▪ WOMEN: Men ratio = 10-14:1 ▪ Predilection: ANT of MAND ▪ Asymptomatic, all teeth are VITAL (EXAM!!!)  ▪ ▪ Periodontal ligament stays INTACT w/ NO bone expansion ▪ Stade OSTEOBLASTIQUE = MIXTE lesion ; radio-opaque centre in radioclaire lesion ▪ Stade MATURATION = +++ radio-opaque with thin radioclaire contour ▪ Histopathology: maturation –> amas os lamellaire + spherules denses, peu vascularisé o Focale: ▪ WOMEN, 20-50 yo = 90% patients ▪ BLACKS +++, but also seen in whites (contrary to periapical) ▪ Predilection: POST of MAND ▪ Possible expansion, but RARE ▪ DX dif: fibrome cémento-ossifiante (EXPANSION!) ▪ 3 stages: radio-claire, mixte, radio-opaque with WELL-defined irregular periphery ▪ ++ zone édentée, but also apex ▪ No TX o Floride : ▪ BILATERAL + MULTIFOCAL ▪ WOMEN, BLACK, average aged ▪ Predilection : POST of maxillaries ▪ DX dif : maladie Paget (IF +++ EXPANSION) ▪ Maturation phase may : GENERALIZED effect on alveolar bone ▪ Radioclaire lesions (kystes traumatique)can develop in radio-opaque regions ▪ Maturation: radio-opaque lesion surronded by radio-CLAIRE line  ▪ Clinical : most DANGEROUS –> bone is sclerotic, little vascularization susceptible to OSTEOMYELITE ▪ Pt must have EXCELLENT HYGIENE + regular visits ▪ Active infection: ANTIBIOTICS, not effective thought (may need excision of bone) Cémentome gigantiforme familiale: HERIDITAIRY AD, very RARE, WHITES (EXAM!!!) Benign neoplasm of maxillary: 1. Fibrome cémento-ossifiante: Benign neoplasm Demography: WOMEN 5:1, WHITE > African > others Predilection: premolar-molar of MAND (EXAM!!) RX: o Well DEFINED, UNILOCULAR, radio-claire/mixte o Usually has thin radio-claire line o Teeth are moved/resorbed o Expansion osseuse concentrique POSSIBLE o Curvature of INF border of MAND = characteristic of MAND lesions Histopathologie: VASCULARIZED fibrous CAPSULE , large single fragment tumor (easily removed) or many large fragments ; OSTEOBLASTIC rimming (surrounding), immature bone trabeculae, little hemorrhage TX: enucleation, excellent prognosis, NO risk of malignancy or recurrence 2. Chondrome: Tumor of CARTILLAGE, only in maxillaries  DX dif: chondrosarcoma bien différencié (EXAM !!) Predilection : ANT of MAX + condyle TX : AGGRESIVE, complete ablation, condylotomy (if touches condyle) 3. Ostéome: Composed of MATURE, lamellar (compact) and SPONGIOUS bone Predilection : head & neck and maxillo-facial region Slow, asymptomatic growth, possible facial ASYMETRY RX: dense, radio-OPAQUE Multiple osteoma: Gardner syndrome: o APC gene, chromosome 5, AD o 1/3 cases = NEW mutation o Osteoma localized on angle of mandibula = VERY characteristic o +++ dents SURNUMERAIRES INCLUSES, odontomes, kystes dentifères o Polypes intestinaux (13-25 yo) = close to 100% risk malignancy!! (early dx allows resection of colon and saves lives) o Extra-oral: epidermic cysts, cutaneous fibroma, desmoid tumors Ostéome ostéide: o LESS than 2 cm o Very RARE in maxillaries o Nocturnal pain helped by aspirin, tumor secretes prostaglandin o RX: radio-claire (or radio-opaque centre), well-defined, osteosclerotic contour Osteoblastoma: o Maxillaries = 10% cases o WOMEN, POST of MAND o 85% cases in YOUNG pt (