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ABNORMALITIES OF TEETH Environmental Alterations of Teeth Developmental Alterations of Teeth 牙齒的異常-環境與發育的影響 王文岑 高雄醫學大學 牙醫學系 [email protected] ENVIRONMENTAL ALTERATIONS OF TEETH Developmental tooth defects Turner’s tooth Hypoplasia caused by antineoplastic therapy Fluorosis Syphilitic hypoplasia Postdevelopmental structure loss Tooth wear Internal and external resorption Discolorations of teeth Intrinsic stains Extrinsic stains Localized disturbances in eruption Primary impaction Ankylosis Wen-Chen Wang Enamel development Three stages: 1. Matrix formation: protein laid down 2. Mineralization: minerals deposition, majority of original prot. removed-- diffuse, opaque white, soft enamel 3. Maturation: final mineralization-- translucent, hard enamel Amelogenesis imperfecta Enamel hypoplasia Wen-Chen Wang Enamel development No remodeling after initial formation Timing of ameloblastic damage has a great impact on location & appearance of the defect Development of crown : from 14th week of gestation to 12 months of age in deciduous dentition; 6 months to 15 y/o in permanent dentition Neonatal ring on deciduous enamel and deposition with a rate of 0.023mm/day Wen-Chen Wang See Box 2-2 Factors associated with enamel defects Systemic1. Birth-related trauma: premature birth 2. Chemicals: antineoplastic C/T, fluoride, tetracycline 3. Chromosomal abnormalities: trisomy 21 4. Infections: chicken pox, CMV, syphilis 5. Inherited diseases: Vit.D-dependent rickets 6. Malnutrition: Vit. A deficiency 7. Metabolic disorders: hypoparathyroidism, maternal diabetes 8. Neurologic disorders: cerebral palsy Wen-Chen Wang See Box 2-2 Factors associated with enamel defects Local1.Local acute mechanical trauma 2. Electric burn 3. Irradiation 4. Local infection: periapical inflammatory disease Clinical and Radiographic Features Environmental enamel defects: 1.Hypoplasia: pits, grooves or large area of missing enamel 2. Diffuse opacities: variation in translucency, normal thickness, white opacity without clear boundary 3. Demarcated opacities: increased opacity, a sharp boundary with adjacent normal enamel, normal thickness Wen-Chen Wang Turner’s hypoplasia, Turner’s tooth Permanent teeth Periapical inflammatory disease of the overlying deciduous tooth, less frequently in anterior teeth Traumatic injury- not rare -45% children sustain injury to their deciduous teeth, 23% Turner’s hypoplasia secondary permanent teeth development disturbed to previous trauma Wen-Chen Wang Turner’s teeth Wen-Chen Wang Hypoplasia caused by antineoplastic therapy Under 12 y/o, esp. under 5y/o Age at treatment, forms of therapy Chemotherapy Less alteration than radiation Increased number of enamel hypoplasia and discolorations, slight smaller tooth size, radicular hypoplasia Wen-Chen Wang Radiotherapy 0.72 Gy related to mild defects in enamel, dentin (一般成人頭頸癌照射一次約為2Gy) Dose, radiation field Wen-Chen Wang Developmental radicular hypoplasia and microdontia caused by radiotherapy Wen-Chen Wang Hypodontia, microdontia, radicular hypoplasia, enamel hypoplasia, mandibular hypoplpasia, reduced in vertical development of lower 1/3 of face Mandibular hypoplpasia may caused by Radiation →impaired root development →reduced alveolar bone growth Cranial radiation→ altered pituitary gland function→ growth failed Wen-Chen Wang *Dental fluorosis 1901, Dr. Frederick S. McKay: Colorado brown stain 1909, Dr. F.L. Robertson in Bauxite, Arkansas 1930, H.V. Churchill: high concentration of fluoride of Bauxite(13.7ppm) and Colorado 1931, Dr. H. Trendley Dean: association between fluoride, dental fluorosis and prevalence of caries among children 1.0 ppm reduced caries by 50~70% and associated with low and mild mottled enamel 0.7~1.2 ppm water fluoridation was recommended after 1962, currently 0.7ppm is recommended due to increased dental fluorosis Wen-Chen Wang Dental fluorosis Retention of the amelogenin protein in enamel structure → hypomineralized enamel → permanent hypomaturation → increased surface and subsurface porosity → alters light reflection and create white, chalky area Wen-Chen Wang Dental fluorosis Critical period for clinical dental fluorosis is the 2nd and 3rd year of life, dose dependent Caries resistant Wen-Chen Wang Syphilitic hypoplasia •Congenital syphilis •Hutchinson’s incisors & mulberry molars Wen-Chen Wang POSTDEVELOPMENTAL LOSS OF TOOTH STRUCTURE Begin from enamel surface (tooth wear): Attrition, abrasion, erosion, abfraction Begin from dentin, cemental surface: internal or external resorption Wen-Chen Wang Attrition Tooth to tooth contact during occlusion and mastication, some are physiologic Accelerated by: poor quality or absent enamel, premature contact, intraoral abrasives, erosion, grinding habits Incisal, occlusal and interproximal surfaces Wen-Chen Wang Abrasion Pathologic loss of tooth structure or restoration secondary to the action of an external agent (ex. Toothbrush, hair grips, toothpicks, chewing tobacco, biting thread, dental flossing…) Toothbrush abrasion: horizontal buccal cervical notches of exposed radicular cementum and dentin with smooth surface. Greater on prominent teeth ( canines, premolars , and teeth adjacent to edentulous area) and side of the arch opposite to the dominant hand Demastication- when tooth wear is accelerated by chewing an abrasive substance between opposing teeth (both attrition and abrasion) Wen-Chen Wang Abrasion Wen-Chen Wang Improper use of hair grips Abrasion Long-term use of tobacco pipe Wen-Chen Wang Erosion Chemical process, exposure to acidic foods or drinks, medications (chewable Vit. C, aspirin), involuntary regurgitation (ex. esophagitis, pregnancy), voluntary regurgitation (ex. psychologic problems, bulimia) Perimolysis- dental erosion from gastric secretion Facial surface of maxillary anteriors affecteddietary source Posterior teeth extensive loss of occlusal surface, and palatal surface concave dentin surrounded by an elevated enamel rim- regurgitation of gastric secretion Wen-Chen Wang Erosion concave dentin surrounded by an elevated enamel rim Wen-Chen Wang Erosion A bulimia patient Wen-Chen Wang Abfraction Repeated tooth flexure caused by occlusal stresses (tensile stress) → concentrate at the cervical fulcrum → may produce disruption in the chemical bonds of enamel crystal →cracked enamel can be lost or removed by erosion or abrasion Wedge-shaped cervical defects, deep, narrow Vshaped, not allow toothbrush to contact base; if the defect, often affect a single tooth Almost exclusively on facial surface and more often in bruxism, higher in mandibular dentition Wen-Chen Wang Abfraction Wen-Chen Wang Treatment and prognosis of tooth wear Resolve pain and sensitivity Identify the cause of tooth structure loss Protection Wen-Chen Wang INTERNAL & EXTERNAL RESORPTION Internal resorption- by cells located in pulp, rare Follows injury to pulp tissues, physical trauma or caries, continue as long as vital pulp remains, may result in communication of the pulp and PDL External resorption- by cells in PDL, common Wen-Chen Wang Factors associated with external resorption Wen-Chen Wang Clinical and Radiographic Features Internal resorption Inflammatory resorptiondentin replaced by inflamed granulation tissue Pink tooth of Mummery: internal resorption involved coronal pulp Balloonlike enlargement of the canal Replacement, or metaplastic absorption- pulpal dentinal walls are replaced by bone or cementum-like bone Wen-Chen Wang Clinical and Radiographic Features External resorption Moth-eaten loss of tooth structure, less well-defined and variation in density in radiography Most involved apical or midportions of root, occasionally, begin from cervical (invasive cervical resorption) Wen-Chen Wang Histopathologic Feature • Increased cellularity, vascularity and collagenization • Numerous multinucleated dentinoclasts • Inflammatory cells infiltration Wen-Chen Wang Treatment and prognosis Internal resorption Removal of all soft tissue from site of resorption Endodontic treatment before perforation in internal resorption Placement of calcium hydroxide paste for remineralization Surgical exposure and restoration Extraction External resorption Identification and elimination the accelerating factor Wen-Chen Wang ENVIRONMENTAL DISCOLORATION OF TEETH Extrinsic- surface accumulation of exogenous pigment Intrinsic-secondary to endogenous factors that result in discoloration of underlying dentin Wen-Chen Wang Extrinsic stains Bacterial- Chromogenic bacteria, green, black-brown, orange coloration Frequently in children, labial surface of maxillary ant. in gingival third Iron- formation of ferric sulfide Tobacco Food and beverage- chlorophyll Gingival hemorrhage- Hb. breakdown to biliverdin Restorative material – ex. Amalgam Medications- iron, iodine, silver nitrate, chlorhexidine, stannous fluoride Wen-Chen Wang Intrinsic stains Amelogenesis imperfecta Dentinogenesis imperfecta Dental fluorosis Erythropoietic porphyria – autosomatic recessive disorder of porphyrin metabolism, increased synthesis and excretion of porphyrins and their related precursors Porphyrin deposition in teeth, reddish-brown coloration, red fluorescence when exposed to a Wood’s UV light Present both in dentin and enamel in deciduous teeth, but only dentin affected in permanent teeth Wen-Chen Wang Erythropoietic porphyria Hyperbilirubinemia Wen-Chen Wang Intrinsic stains Hyperbilirubinemia- bilirubin, breakdown product of RBC, jaundance (yellow-green discoloration), erythroblastosis fetalis, biliary atresia Biliverdin deposition, green discoloration of teeth (chlorodontia) Ochronosis-alkaptonuria, blue-black discoloration Trauma- coronal discoloration, pulp necrosis Localized RBC breakdown Wen-Chen Wang Intrinsic stains MedicationsTetracycline (bright yellow to dark brown), chlortetracycline (gray-brown), oxytetracycline (yellow) , minocycline hydrochloride Time of administration dose, duration Avoid from pregnancy up to 8 yrs of age Wen-Chen Wang Minocycline hydrochloride Tx for Acne Blue-gray from incisal 3/4, to dark green or black in roots, also affect developed teeth Skin, nail, sclera, conjunctiva, thyroid, bone discoloration in susceptible individuals Stained alveolar bone Wen-Chen Wang Treatment and prognosis Extrinsic stains- polishing Intrinsic stains- bleaching, bonded restoration, crowns Wen-Chen Wang LOCALIZED DISTURBANCES IN ERUPTION PRIMARY IMPACTION- Teeth cease to eruption before emergence ANKYLOSIS -Cease of eruption after emergence and anatomic fusion of tooth cementum or dentin with alveolar bone Wen-Chen Wang Impaction 3rd molars, maxillary canines, mandibular premolars, mandibular canines, maxillary premolars, maxillary central incisors, maxillary lateral incisors, and mandibular second molars; usually angulated or diverted Factors associated with impaction: Crowding and deficient maxillofacial development Overlying cysts or tumors Trauma Reconstructive surgery Thickened overlying bone or soft tissue A host of systemic disorders, diseases or syndromes Wen-Chen Wang Classification : Partially erupted or full bony impaction according to angulation: Mesioangular, distoangular, vertical, horizontal or inverted Eruption sequestrum Wen-Chen Wang Treatment and Prognosis Choice of treatment: Long-term observation Orthodontically assisted eruption Transplantation Surgical removal The risks associated with nonintervention: Crowding dentition Resorption and worsening of the periodontal status of adjacent teeth Development of pathologic conditions, ex infections, cysts or tumors Wen-Chen Wang The risks associated with intervention: Transient or permanent sensory loss Alveolitis Trismus Infection Fracture TMJ injury Periodontal injury Injury to adjacent teeth Wen-Chen Wang ANKYLOSIS Infraocclusion, secondary retention, submergence, reimpaction, reinclusion Wen-Chen Wang ANKYLOSIS Clinical And Radiographic Features Pathogenesis is unknown, may be secondary to many factors and result in PDL barrier deficiency. May occur at any age, any tooth Most affect 8~9yr-old children and D , E , D , E PDL absent Occlusal, periodontal problems, impaction of the underlying teeth Treatment and Prognosis Variable : extraction, orthodontics, segmental osteotomy Wen-Chen Wang DEVELOPMENTAL ALTERATIONS OF TEETH NUMBER Hypodontia Hyperdontia SIZE Microdontia Macrodontia STRUCTURE Amelogenesis imperfecta Dentinogenesis imperfecta Dentin dysplasia I & II Regional odontodysplasia SHAPE Gemination, Fusion, Concrescence Accessary cusps Dense in dente Ectopic Enamel Taurodontism Dilaceration Hypercementosis Supernumerary roots Wen-Chen Wang Missing teeth 1.6-9.6% , excluding 3rd molars, female predominance Hypodontia: missing one or more teeth Oligodontia: missing 6 or more teeth Anodontia: total missing 8>5>2>1 Deciduous mandibular incisors Gene mutation, ex: PAX9, MSX1, AXIN2 gene, HeZhao deficiency, maps to chromosome 10q11.2 AXIN2 mutation: associated with the development of adenomatous polyps of colon, and colorectal carcinoma Ectodermal dysplasia orofaciodigital syndrome Wen-Chen Wang Hypodontia Wen-Chen Wang Ectodermal dysplasia Wen-Chen Wang Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept. Supernumerary teeth, hyperdontia Mesiodens 4th molar Paramolar Distomolar, distodens deciduous - lat. incisors 86% single supernumerary multiple & impaction cleidocranial dysostosis Gardner’s syndrome Wen-Chen Wang Mesiodens The most common in supernumerary. Premaxillary area , usually between upper central incisors Cone-shaped crown & short root One or two in number Wen-Chen Wang Wen-Chen Wang Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept. Cleidocranial dysostosis 1.Skull: flat appearance, sutures remain open 2.Jaws: underdeveloped, high narrow palate 3.Teeth: prolonged retained deciduous teeth, delayed eruption of permanent teeth 4.Clavicles: complete or partial absent Wen-Chen Wang Wen-Chen Wang Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept. Wen-Chen Wang Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept. Wen-Chen Wang Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept. Wen-Chen Wang Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept. Wen-Chen Wang Gardner’s syndrome 1.multiple polyposis of the large intestine 2.osteoma of the bone 3.multiple epidermoid cysts or sebaceous cysts of the skin 4.desmoid tumors 5.impacted supernumerary & permanent teeth Wen-Chen Wang Predeciduous dentition Neonatal teeth: within 30 days Natal teeth: newborns Most are prematurely erupted deciduous teeth Removal only if mobile and at risk of aspiration Wen-Chen Wang Wen-Chen Wang Microdontia True: 1.General -pituitary dwarfism 2. Single -peg lat., 3rd molar Relative microdontia Wen-Chen Wang Macrodontia True macrodontia : 1. Generalized-pituitary gigantism 2. Localized- single, hemifacial hypertrophy Relative macrodontia: small jaw, child Wen-Chen Wang Wen-Chen Wang Gemination, Fusion, Concrescence Wen-Chen Wang Gemination single tooth germ division single root & root canal + 2 complete or incomplete separated crowns tooth no.: normal twinning Wen-Chen Wang Fusion Union of 2 separate tooth germs Contact of tooth germ before calcified Confluent of the dentin Complete- form a single tooth Incomplete- after calcified begins Tooth no. : less one Wen-Chen Wang Concrescence Fusion after root formation Cementun united Traumatic injury or crowding Pre-extraction x-ray check Wen-Chen Wang Talon cusp Eagle’s talon Lingual projection from the cingulum area of ant. teeth Most contain a pulp horn Both in deciduous & permanent dentition Wen-Chen Wang Dens evaginatus ( central tubercle, occlusal tuberculated premolar; Leong’s premolar; evaginated odontome; occlusal enamel pearl ) An accessory cusp or a globule of enamel on central groove or buccal cusp of premolars or molars; unilateral or bilateral. 15% in Asians, rare in whites Wen-Chen Wang Dens evaginatus Wen-Chen Wang Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept. Shovel-shaped incisors Wen-Chen Wang Dens in dente (Dens invaginatus; Dilated composite odontome) Tooth within a tooth, incidence 5% Invagination of the enamel organ into dental papilla before calcification Coronal type: 3 types maxillary lateral incisors are common Wen-Chen Wang Dens invaginatus, coronal type II Wen-Chen Wang Dens invaginatus Radicular type Hertwig’s sheath invagination Food deposition→ caries → pulp infection Restorated as soon as possible Wen-Chen Wang Taurodontism “ teeth Bi- or trifurcation near the apex Pulp chamber : greater apico-occlusal height and no constriction at the cervical of the tooth “Bull-like Wen-Chen Wang Syndromes associated with taurodontism Wen-Chen Wang Hypercementosis Wen-Chen Wang Supernumerary roots Any tooth may develop accessary roots No tx required, but critical important in endodontic procedure Wen-Chen Wang Dilaceration Angulation, sharp bend of root or crown Trauma during tooth is forming Pre-extraction x-ray check Wen-Chen Wang Amelogenesis imperfecta (Hereditary enamel dysplasia; Hereditary brown enamel; Hereditary brown opalescent teeth) Defects in- Formative stage→hypoplastic type → defective formation of matrix Calcification stage →hypocalified → defective mineralization of formed matrix Maturation stage → hypomaturation → enamel crystallites remain immature Genes mutation : AMELX, ENAM, MMP-20, KLK4, DLX3 Wen-Chen Wang Amelogenesis imperfecta Wen-Chen Wang 1.Hypoplastic type Thin enamel with pitted, rough or smooth & glossy surface; yellowish to brown undersized, squared crown, lack of contact flat occlusal surface & low cusps, attrition Wen-Chen Wang Hypoplastic type Wen-Chen Wang Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept. Hypoplastic type Wen-Chen Wang 2.Hypomaturation normal thickness of enamel, but mottled surface; cloudy white, yellow or brown, opaque in color softer than normal same density as dentin Wen-Chen Wang Hypomaturation type Kaohsiung Medical University, Oral Pathology and image Diagnosis Wen-Chen Dept. Wang 3.Hypocalcified type normal thickness of enamel, density less than dentin normal size & shape when erupt, abrade or fracture away rapidly permeability increase, darkened & stained 4.Hypomaturation-hypocalcified with taurodontism Wen-Chen Wang Hypocalcified type Wen-Chen Wang Tricho-dento-osseous syndrome Hypoplastic-Hypomaturation type Wen-Chen Wang Dentinogenesis imperfecta (Hereditary opalescent dentin) Classification of DI : (Shields) Type I : DI + OI (osteogenesis imperfecta) COL1A1, COL1A2 Type II : Isolated DI. (1/8000) DSPP Type III: DI of the Brandywine type * DSPP A racial isolate in Maryland, DI + multiple pulp exposures in deciduous teeth Wen-Chen Wang Osteosclerosis imperfecta Blue sclera M Greenwood, J G Meechan,:General medicine and surgery for dental practitioners Part 8: Musculoskeletal system. British Dental Journal 2003 (195) 243 - 248 , Wen-Chen Wang Clinical features type I : deciduous severe than permanent teeth; type II: equally affected; type III: both dentitions affected. Gray to brownish violet or yellowish brown color, with translucent or opalescent hue. Enamel lost early through fracture, esp. on the incisal & occlusal surface, and dentin attrition rapidly. Caries rate is not increased. Wen-Chen Wang Dentinogenesis imperfecta Wen-Chen Wang Dentinogenesis imperfecta Histology: 1.pulp chamber obliterated with dentin 2.flatten D-E junction 3.atypical granular dentin, enlarged tubles, poor calcification water contents: 50% above normal Wen-Chen Wang Radiographic features Partial or total obliteration of the pulp chamber & root canal by continued formation of dentin, in both dentitions. Short and blunted roots Normal cementum, PDL & supporting bone Wen-Chen Wang Shell teeth Initial reported in the Brandywine population Normal thickness of enamel associated with extremely thin dentin and dramatically enlarged pulps (due to insufficent and deffective dentin formation) Short roots. Wen-Chen Wang Wen-Chen Wang Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept. Dentin dysplasia Hereditary, autosomal dominant. Normal enamel but atypical dentin formation with abnormal pulp morphology Type I (radicular type): “Rootless teeth” Type II (coronal) DSPP (dentin sialophosphoprotein) gene mutation Wen-Chen Wang Type I (radicular type) Radiographically: deciduous teeth affected more severely, little or no pulp, short or absent roots. If disorganization late---normal pulp chambers, with a large pulp stone. periapical lesions (R-L) no obvious cause. Histologic features Normal coronal enamel& dentin. In root: tubular dentin and atypical osteodentin surrounded with normal dentin --- appearance of “ Lava flowing around boulders”. Wen-Chen Wang Dentin dysplasia, type I Wen-Chen Wang Type II (coronal) Normal root length in both dentitions. Primary dentition similar to DI: bulbous crowns, cervical constriction thin roots , early obliterated pulp. Permanent teeth : normal coloration, thistle tube-shaped or flame-shaped pulp chamber with pulp stones. Wen-Chen Wang Dentin dysplasia, type II (coronal) Wen-Chen Wang “Lava flowing around boulders”. Dentin dysplasia Large pulp stones Wen-Chen Wang Regional odontodysplasia (odontodysplasia; odontogenic dysplasia; odontogenesis imperfecta; ghost teeth) One or several teeth in a localized area Maxi. > Mand.; both dentitions most in ant. area Delayed or total failure eruption Irregular appearance Defective mineralization Wen-Chen Wang Radiographic features 1. Radiodensity ↓, “ghost appearance” 2. Large pulp, thin enamel & dentin Histologic features 1. Dentin↓ 2.Widening of the predentin layer, 3. Interglobular dentin and an irregular tubular pattern of dentin ↑ 4.Calcification of the reduced enamel epi. Wen-Chen Wang Enameloid conglomerates Odontogenic epithelium Regional odontodysplasia Wen-Chen Wang Summary ENVIRONMENTAL ALTERATIONS OF TEETH Developmental tooth defects Turner’s tooth Hypoplasia caused by antineoplastic therapy Fluorosis Syphilitic hypoplasia Postdevelopmental structure loss Tooth wear Internal and external resorption Discolorations of teeth Intrinsic stains Extrinsic stains Localized disturbances in eruption Primary impaction Ankylosis Wen-Chen Wang Summary DEVELOPMENTAL ALTERATIONS OF TEETH NUMBER Hypodontia Hyperdontia SIZE Microdontia Macrodontia STRUCTURE Amelogenesis imperfecta Dentinogenesis imperfecta Dentin dysplasia I & II Regional odontodysplasia SHAPE Gemination, Fusion, Concrescence Accessary cusps Dense in dente Ectopic Enamel Taurodontism Dilaceration Hypercementosis Supernumerary roots Wen-Chen Wang
