5. Environmental defects 2 .pdf

Developmental And Environmental Defects Of Teeth II MOHAMMAD ALRASHDAN BDSc,MSD,DCD,MRACDS,FDS RCSEd 12/10/2023 1 Learning objectives Recall the developmental, hereditary and idiopathic defects of teeth. Identify the epidemiology and aetio-pathogenesis of such defects. Outline the clinical and rad...

Developmental And Environmental Defects Of Teeth II MOHAMMAD ALRASHDAN BDSc,MSD,DCD,MRACDS,FDS RCSEd 12/10/2023 1 Learning objectives Recall the developmental, hereditary and idiopathic defects of teeth. Identify the epidemiology and aetio-pathogenesis of such defects. Outline the clinical and radiographic (when applicable) features of such defects. List down the differential diagnosis for hereditary and developmental teeth defects. Outline the principles for the management of such defects where applicable. 2 Impaction Q.whqtfmtfacti.tn • Total failure of tooth eruption. a Ehidingftp.akted • Mandibular third molars are most commonly affected, followed by maxillary 3rd molars and maxillary canines. • Hard-tissue impaction Vs soft-tissue impaction Whating thentypesof • Common causes Crowding and insufficient maxillofacial development Abnormal angulation or orientation of teeth Overlying cysts or tumors Gwhat mpractises Trauma Reconstructive surgery Systemic diseases or syndromes I 3 Impaction 4 Impaction QWhatare • Potential complications ofimpaction Root resorption, caries or periodontal disease Development of pathologic conditions (e.g. cysts, infections) Crowding? 5 Impaction QWhatare • Treatment options Observation Surgical removal- in the presence of infections, tumors, cysts Orthodontically- assisted eruption Transplantation • Surgical removal of asymptomatic impacted teeth?? 6 Ankylosis "Cession of eruption after emergence" refers to a situation where a tooth stops moving or growing upward after it has already come through the gum (emerged). In simpler terms, it means the tooth has partially come in, but then it just stays in that position and doesn't continue to grow into its normal place. 0whatsAnkylosis • The cessation of eruption after emergence is termed ankylosis and occurs from an anatomic fusion of tooth cementum or dentin with the alveolar bone. • Synonyms : infra-occlusion, submergence, secondary retention. • Potential causes: Disturbances from changes in local metabolism, trauma, injury • Occurs most commonly in the first 2 decades of life. 7 Ankylosis • Mandibular primary first molar > mandibular primary second molar > maxillary primary first molar> maxillary primary second molar. • Ankylosis of permanent teeth is uncommon. 8 Ankylosis • The occlusal plane of the involved tooth is below that of the adjacent dentition (infraocclusion). • PDL space is absent on radiographs. • Variable treatment options for ankylosed primary molars, extraction ± space maintenance or prosthetic build up. 9 Developmental alterations in the number of teeth • Hypodontia : lack of development of one or more teeth. • Oligodontia: lack of development of 6 or more teeth- excluding 3rd molars. • Anodontia: total lack of tooth development (extremely rare). • Hypodontia is associated with non-syndromic cleft lip or cleft palate. • 3rd molars > second premolars > lateral incisors. 10 Developmental alterations in the number of teeth From: Neville, B.W., Damm, D.D., Allen, C. and Chi, A.C., 2015. Oral and maxillofacial pathology. Elsevier Health Sciences. 11 Hypodontia 12 Developmental alterations in the number of teeth • Hyperdontia : the development of an increased number of teethcalled supernumerary teeth. • The prevalence in permanent dentition is between 0.1% and 3.8%. ismorecommon morecommonthan than • Single-tooth hyperdontia > multiple, maxilla > mandible, anterior area are the most common patterns. • the most common site is the maxillary incisor region, followed by maxillary fourth molars and mandibular fourth molars, premolars, canines and lateral incisors. Maxinciors Max417 man419 ManPM Mank 13 Developmental alterations in the number of teeth Supernumerary teeth developed Supplemental Rudimentary Conical Tuberculate smakpg.gg I Molariform tyhesetmswm.in 15 Developmental alterations in the number of teeth • A supernumerary tooth in the maxillary anterior incisor region is termed a mesiodens 16 Developmental alterations in the number of teeth • an accessory fourth molar is often called a distomolar or distodens • A posterior supernumerary tooth situated lingually or buccally to a molar tooth is termed a paramolar 17 Developmental alterations in the number of teeth • Dental transposition: normal teeth erupting into an inappropriate position (e.g., a canine present between two premolars). 01 pkg • Natal/ neonatal teeth: accessory teeth present at or shortly after birth. 18 Developmental alterations in the number of teeth • Complications of hypodontia: spacing of teeth, delayed tooth formation. • Treatment options: no treatment, replacement of missing teeth with prosthesis or implants, orthodontics I • Complications of hyperdontia: interference with normal teeth eruption, crowding, root resorption of adjacent teeth(when impacted),periodontal disease and pathology formation (e.g. cyst or tumor). • Early removal of supernumerary teeth can help reduce complications. 19 Developmental alterations in the size of teeth • Macrodontia: physically larger than normal teeth. • Diffuse macrodontia has been noted in association with pituitary Gigantism, otodental syndrome, XYY males and pineal hyperplasia. • Differentiate from relative macrodontia 20 Developmental alterations in the size of teeth • Microdontia: physically smaller than normal teeth. • Maybe seen in Down syndrome and in pituitary dwarfism. • maxillary lateral incisor is most commonly involved- peg shaped lateral • Differentiate from relative microdontia 21 Developmental alterations in the shape of teeth • Gemination : a single enlarged tooth or joined (i.e., double) tooth in which the tooth count is normal when the anomalous tooth is counted as one. • In both dentitions, incisors and canines are the most commonly is a dental anomaly where a single tooth tries to divide into two affected teeth. IGemination 1the division is incomplete. The result is a teeth during its development, but I tooth that appears as a larger, joined tooth, often resembling two teeth that are fused together. Despite the appearance of two crowns, there is only one root and one pulp canal. The de nition you provided, "a single enlarged tooth or joined (i.e., double) tooth in which the tooth count is normal when the anomalous tooth is counted as one," means that when dentists are counting the number of teeth in a person's mouth, they would typically count a geminated tooth as a single tooth. Even though it may look like two teeth, it is considered one tooth in terms of the overall tooth count. 22 Fusion is a dental anomaly in which two separate teeth fuse together during development, resulting in a tooth that appears as a single, larger tooth. In the de nition you provided, "a single enlarged tooth or joined (i.e., double) tooth in which the tooth count reveals a missing tooth when the anomalous tooth is counted as one," there are a few key points to understand: Developmental alterations in the shape of teeth • Fusion: a single enlarged tooth or joined (i.e., double) tooth in which the tooth count reveals a missing tooth when the anomalous tooth is Single Enlarged Tooth or Joined Tooth: counted as one. Fusion involves the union of two adjacent teeth, creating the appearance of a larger or joined tooth. Tooth Count Reveals a Missing Tooth: When counting the teeth in the mouth, the fused tooth is considered as one, which means that the total tooth count appears normal. However, because two teeth have fused together, there is an actual missing tooth in the dental arch. In simpler terms, fusion results in the fusion of two teeth into one, giving the appearance of a larger tooth. When dentists count the teeth, they consider the fused tooth as one unit. However, because the fused tooth represents the union of two originally separate teeth, there is a missing tooth in the overall dental arch. 23 Developmental alterations in the shape of teeth • Concrescence: union of two adjacent teeth by cementum alone, without confluence of the underlying dentin. • Most commonly in posterior maxilla, 2nd molar with 3rd molar. 24 Developmental alterations in the shape of teeth • Accessory cusps The cusp of Carabelli is an accessory cusp located on the palatal surface of the mesiolingual cusp of a maxillary molar. A talon cusp is a well-delineated additional cusp that is located on the surface of an anterior tooth and extends at least half the distance from the cementoenamel junction to the incisal edge. 25 Developmental alterations in the shape of teeth • Dens evaginatus: a cusplike elevation of enamel located in the central groove or lingual ridge of the buccal cusp of premolar or molar teeth. • The accessory cusp normally consists of enamel and dentin, with pulp present in about half of the cases. 1 26 Developmental alterations in the shape of teeth • Dens invaginatus (dens in dente): a deep surface invagination of the crown or root that is lined by enamel. • Treatment depends on the type and ranges from simple restorations to root canal therapy. 27 Developmental alterations in the shape of teeth • Ectopic enamel: the presence of enamel in unusual locations, mainly the tooth root. Enamel pearls: hemispheric structures that may consist entirely of enamel or contain underlying dentin and pulp tissue. cervical enamel extensions also occur along the surface of dental roots 28 Developmental alterations in the shape of teeth • Taurodontism: an enlargement of the body and pulp chamber of a multirooted tooth, withcause apical j displacement of the pulpal floor and bifurcation of the roots. • Affected teeth tend to be rectangular with a dramatically increased apico-occlusal height. 29 Developmental alterations in the shape of teeth • Hypercementosis: nonneoplastic deposition of excessive cementum that is continuous with the normal radicular cementum. • Radiographically, affected teeth demonstrate a thickening or blunting of the root. • Mandibular molars are most commonly involved. 30 Developmental alterations in the shape of teeth Hypercementosis 31 Developmental alterations in the shape of teeth • Dilaceration: an abnormal angulation or bend in the root or, less frequently, the crown of a tooth. • Most examples are idiopathic or due to trauma. • Most commonly affected teeth are the mandibular third molars, followed by the maxillary second premolars and mandibular second molars. 32 Developmental alterations in the shape of teeth • Supernumerary roots: the development of an increased number of roots on a tooth compared with that classically described in dental anatomy. • Most commonly affected teeth are 3rd molars. 33 Hereditary alterations in the structure of teeth • Hereditary alterations in the structure of Enamel • Amelogenesis Imperfecta • Hereditary alterations in the structure of dentin • Osteogenesis imperfecta with opalescent teeth • Dentinogenesis Imperfecta • Dentin Dysplasia 34 Hereditary alterations in the structure of enamel • Amelogenesis imperfecta: the hereditary defects of the enamel formation , at least 14 different hereditary subtypes identified. • They are divided into: Hypoplastic Hypocalcified Hypomaturation 35 Hereditary alterations in the structure of enamel • I- Hypoplastic Amelogenesis Imperfecta: Type I (A-G) • Inadequate deposition of enamel matrix. Generalized pitted type: (Type IA) • Localized pitted type: (type I B&C) 36 Hereditary alterations in the structure of enamel • Diffuse type Smooth (type I D &E) Rough (type I F) 37 Hereditary alterations in the structure of enamel • Enamel Agenesis (Type I G) Complete or almost complete absence of enamel. 38 Hereditary alterations in the structure of enamel • II-Hypocalcification Amelogenesis Imperfecta: • Enamel matrix is normal, but no significant mineralization occurs. • Enamel is very soft & easily lost. • Diffuse : Type A&B 39 Hereditary alterations in the structure of enamel • • • III. Hypomaturation Amelogenesis Imperfecta: A defect in the maturation of enamel crystal structure. Affected teeth are normal in shape, but exhibit a mottled, opaque whitebrown-yellow discoloration. Enamel is softer than normal & easily chipped from underlying dentin. Diffuse : type II A&B Snow Capped : type C&D 40 Hereditary alterations in the structure of enamel IV. Amelogenesis Imperfecta with Taurodontism (Hypomaturation/Hypoplastic Amelogenesis Imperfecta) 41 Hereditary alterations in the structure of enamel • AMELX gene is associated with E. protein “amelogenin” which constitute 90% of enamel matrix. • ENAM gene is associated with “enamelin” which represents 1-5% of enamel matrix. • KLK4 • DLX3 gene 42 Hereditary disorders of dentin From: Neville, B.W., Damm, D.D., Allen, C. and Chi, A.C., 2015. Oral and maxillofacial pathology. Elsevier Health Sciences. 43 Hereditary alterations in the structure of dentin • Isolated or syndrome associated • • • • • • Osteogenesis imperfecta Ehlers-Danlos syndrome Goldblatt syndrome Schimke immuno-osseous dysplasia vitamin-D resistant rickets vitamin-D dependent rickets 44 Hereditary alterations in the structure of dentin • Dentinogenesis imperfecta (DGI) is a hereditary developmental disturbance of the dentin associated with any one of a number of mutations of the DSPP gene.DSPP gene (dentin sialophosphoprotein gene) • DGI affects teeth in both dentitions with the severity of the dental alterations varying with the age at which the tooth develops. • The dentitions have a blue-to-brown discoloration, often with a distinctive translucency. • The enamel frequently separates easily from the underlying defective dentin. 45 Shell Teeth Dentinogenesis Imperfecta 46 Hereditary alterations in the structure of dentin • Dentin dysplasia type II (DD-II; coronal dentin dysplasia) • Represents a variant of DGI • The primary teeth have a blue to- amber-to-brown translucence, similar to dentinogenesis imperfecta. Radiographically, the dental changes include bulbous crowns • The permanent teeth have a normal color clinically; however, radiographically, the pulp chambers exhibit significant enlargement and apical extension. 47 Dentin dysplasia type II (DD-II; coronal dentin dysplasia) 48 Hereditary alterations in the structure of dentin • Dentin dysplasia type I (DD-I; radicular dentin dysplasia) ,referred to as rootless teeth, because the loss of organization of the root dentin often leads to a shortened root length. • Variable presentations 49 Hereditary alterations in the structure of dentin • DDI Clinically normal crowns. Radiographically; shortened roots, absence of pulp canals, and small, crescent-shaped pulp chambers 50 Hereditary alterations in the structure of dentin • Regional odontodysplasia – Ghost Teeth • a localized, nonhereditary developmental abnormality of teeth with extensive adverse effects on the formation of enamel, dentin, and pulp. • Idiopathic but can be associated with certain conditions. 51 Hereditary alterations in the structure of dentin Regional odontodysplasia – Ghost Teeth • Typically, the process affects a focal area of the dentition, with involvement of several contiguous teeth. • Erupted teeth demonstrate small irregular crowns that are yellow to brown, often with a very rough surface. • Radiographically, the altered teeth demonstrate extremely thin enamel and dentin surrounding an enlarged radiolucent pulp, resulting in a pale wispy image of a tooth; hence the term ghost teeth 52 Regional odontodysplasia – Ghost Teeth 53