Dental Anomalies 2 Flashcards
What are the common anomalies of shape?
Double teeth (fusion or germination)
Accessory cusps (Talon cusp or evaginated odontome)
Invaginated odontome
Taurodontism
What causes double tooth?
Inherited
Local factors:
Union of 2 adjacent tooth buds
Partial splitting of one into 2
Tooth germ move together because of crowding or trauma
in who is double tooth most common? Where is it more likely to be seen?
M =F
More common in primary dentition than permanent dentition.
Can be unilateral or bilateral
Predominantly incisor region
More common in the maxilla
Bilateral in primary dentition means more likely having anomalies in permanent dentition
What are the clinical features of double teeth?
Fused teeth might have one or two pulp chambers
Fused teeth commonly exhibit labial and lingual vertical grooves on the crown surface
If the affected tooth is counted as one there is usually one tooth less than normal for a given dental age.
What is gemination?
Gemination is the formation of 2 teeth from the same follicle.
What does gemination look like usually?
One pulp chamber is common
In permanent dentition these teeth are usually macrodonts
Which jaw is gemination more common in?
Gemination is more common in the maxilla
How is diagnosis of root canal morphology from gemination done?
Diagnosis of root canal morphology may be aided by use of CBCT as plain films are difficult to interpret.
What clinical problems are associated with double tooth?
Caries in the groove dividing the bifid crown
Periodontal disease due to extension of the groove to the root surface
Excess arch space and diastema occurs when normal teeth are fused
Crowding of the dental arch, if the fusion involves one normal tooth and a supernumerary tooth
Aplasia of the permanent successor in case of fusion
Delayed exfoliation and root resorption of primary double teeth
Impaction of the permanent successor.
Malocclusion
Esthetic problems
How is double tooth managed?
Fissure sealant
Flowable composite resin
Hemi-section
Reshaping or reduction of a double tooth
Orthodontic treatment and/or prosthetic replacement
Extraction and replacement with an implant
What is a talon cusp?
Process of horn-like shape curving from the base to the cutting edge on the palatal surface of the incisors
Who most commonly gets talon cusp?
Males > Females 1.9:1 ratio
Rare in primary dentition (0.5 - 0.6%)
Observed only in maxillary anterior teeth and involves the incisors and canines
What causes talon cusp?
Unknown
Multifactorial involving both genetic and environmental factors
May occur because of an outward folding of the inner enamel epithelium
Hyperactivity of the dental lamina (commonly in the anterior region)
Due to fusion of a normal and supernumerary tooth
What are the types of talon cusps?
Type 1 = Talon, well defined cusp, extends at least half the distance from the cemento-enamel junction to the incisal edge.
Type 2 = semi-talon, additional cusp of 1mm or more but less than half the distance from the cemento-enamel junction to incisal edge.
Type 3 = trace talon, enlarged and prominent cingulum with variations
What is the radiographic appearance of the talon cusp?
Resembles radio-opaque v-shaped structure pointing towards incisal edge of the tooth.
Cusp image outlined by 2 distinct white lines, representing the enamel.
Which syndromes are associated with talon cusps?
Rubinstein-Taybi syndrome
Mohr syndrome [oral-facial-digital II]
Sturge-weber syndrome
Incontinentia pigmentia
Ellis-van Creveld syndrome [chondroectodermal dysplasia]
Alagille’s syndrome
What are the complications assocaited with talon cusp?
Compromised aesthetics
Traumatic occlusion
Displacement of affected or opposing teeth
Plaque retention
Caries susceptibility in developmental grooves delineate the cusp
Pulpal necrosis
Hypersensitivity
Periodontal problems
Attrition of opposing teeth accidental cusp fracture
Peripaical pathosis due to excessive attrition
Irritation of tongue during speech and mastication
Interference with tongue space
Speech disturbance
Breast-feeding problems
TMJ joint pain due to excessive occlusal forces
How is a talon cusp managed?
Fissure sealants or flowable composite resin to prevent caries in the grooves
If no occlusal interference, no treatment is required
If occlusal interference present: Gradual and periodic reduction of enamel only (to avoid pulp exposure) with fluoride as a de-sensitising agent.
Elective pulpotomy
Partial pulpotomy
Extraction followed by orthodontic treatment.
What is a dens evaginatus?
An enamel covered tubercle projecting from the occlusal surface of a premolar and in rare instances canines and molars.
What causes dens evaginatus?
Unknown:
Multifactorial association with racial and genetic factors.
Abnormal proliferation of the inner enamel epithelium into stellate reticulum of the enamel caused by:
Either an outflowing of the enamel epithelium
Or by a transient focal hyperplasia of the primitive pulpal mesenchyme
Where is a dens evaginatus most commonly located?
Mostly found on permanent teeth
Typically occurs on premolar teeth
Demonstrate marked mandibular predominance
Teeth with dens evaginatus usually occur bilaterally
Prevalence between 0.1% and 4.7%
Frequently seen in mongoloids, Asians, the inuit, and native americans. Rare in whites.
How is dens evaginatus classified?
According to location: Tubercle can arise from lingual ridge of buccal cusp, or center of the occlusal surface.
According to form of the projection: Smooth, grooved, terraced, or ridged.
According to pulp contents within the tubercle (Wide pulp horns, narrow pulp horns, constricted pulp horns, isolated pulp horn remnants, or no pulp horn)
What radiographic examinations should be done for a dens evaginatus?
The pulp tissue in the tubercle is normal unless it is fractured or worn down, thereby permitting bacterial invasion with consequent pulpal necrosis.
Necrosis of pulp can lead to dentoalveolar abscess
Other findings include:
Osteomyelitis
Thickening of periodontal membrane
Periapical rarefaction
Incomplete root formation
Fracture of the root
Cyst formation
Dilaceration
How is dens evaginatus managed?
Composite reinforcement
Grinding of the tubercle
Trauma or attrition to the tubercle results in pulp exposure
Revascularization
Extraction of the tooth
What is a dens invaginatus?
An infolding of the enamel and dentin towards the pulp
AKA:
Warty teeth
Invagination of enamel
Dens in dente
Invaginated odontome
What causes dens invaginatus?
Unknown; several theories:
Growth pressure: Buckling of enamel organ caused by forces in developing arch.
Focal growth retardation: Invagination results from a focal failure of growth of the internal enamel epithelium. Surrounding normal epithelium continues to proliferate and engulfs the static area.
FOCAL PROLIFERATION: Invagination is the result of an invasion of dental papilla by a rapid and aggressive proliferating area of internal enamel epithelium.
Local causes: Trauma and infection
Genetic
How commonly is dens invaginatus seen in primary dentition and on which teeth?
More rare in primary dentition (0.1%) Seen most commonly in primary canine, maxillary central incisors, and mand 2nd molars.
How commonly is dens invaginatus seen in permanent dentition and on which teeth?
0.2 - 10%
Male > female
Maxillary lateral incisors, maxillary central incisors and canines
How is dens invaginatus classified?
Coronal vs radicular
Type 1: Confined to crown
Type 2: Beyond CEJ without involving PA tissues
Type 3: Extends past CEJ and perforating laterally (3a) or apically (3b) at foramen
What are the clinical features of dens invaginatus?
Tooth crowns and roots may exhibit variations in size and form
Invagination allows entry of irritants into the area, predisposing tooth to dental caries. Remember that enamel and dentine is thin between the dens and the pulpal tissues.
Pulp necrosis often occurs within few years of eruption, sometimes even before root end closure.
May lead to abscess formation or cellulitis
Retention or displacement of neighbouring teeth
Cyst formation
Internal resorption
How should dens invaginatus be preventatively managed?
Preventative treatment such as fissure sealants + flowable composite
How should dens invaginatus be restoratively managed?
Composite resin if caries are evident
When should dens invaginatus be endodontically managed?
If symptomatic and root morphology is favourable
When should a tooth with a dens invaginatus be extracted?
If internal anatomy is complex and the root canal is not possible
Infection
Endodontic failure
Orthodontic treatment planning should be carried out prior to extraction.
What is taurodontism?
pulp cavity that tends to enlarge at the expense of the roots
What causes taurodontism?
Unknown: Theory is due to delay or failure of invagination of Hertwig’s epithelial root sheath
What is the prevalence of taurodontism?
M>F
Wide range in reported prevalence (5-60%!)
What other anomalies are commonly associated with taurodontism?
Amelogenesis imperfecta
Hypodontia (35% prevalence in patients with hypodontia)
What are the clinical implications of taurodontism?
Short but very curved canals
Canals difficult to visualize due to length of the pulp chamber
