Q1. Radiographs of a preschool child with________ will show obliteration of the pulp chambers with secondary dentin, a characteristic finding.

1. amelogenesis imperfecta
2. dentinogenesis imperfecta
3. fluorosis
4. enamel hypoplasia

Answer Key: Dentinogenesis imperfecta

Dentinogenesis imperfecta (DI) :

• It is an autosomal dominant trait, its frequency of occurrence is about I in 8000.
• This inherited dentin defect originates during the histodifferentiation stage of tooth development.
• The predentin matrix is defective resulting in amorphic, disorganized, and atubular circumpulpal dentin.
• Teeth are blue-gray or brown and abrade rapidly. Occasionally, these teeth become abscessed as a result of exposure of pulp horns caused by wear.
• Full coverage is the treatment of choice. Both the primary and permanent dentitions are affected in dentinogenesis imperfecta.
• Important: Radiographs of a preschool child with dentinogenesis imperfecta will show obliteration of the pulp chambers with secondary dentin, a characteristic finding. 
• Roots of teeth usually are narrower and appear more fragile. 
• Crowns generally appear more bulbous than usual due to the smaller roots.

• Dentinogenesis imperfecta can be subdivided into three basic types:
• Shields Type I : occurs with osteogenesis imperfecta. As a result of an inherited defect in collagen formation, there is brittle bones, bowing of the limbs, and blue sclera. Periapical radiolucencies, bulbous crowns,obliterated pulp chambers, and root fractures are common. Teeth have amber translucent color. Primary teeth affected more than permanent teeth.
• Shields Type II : also known as hereditary opalescent dentin, tends to occur as a separate entity apart from osteogenesis imperfecta. Same characteristics as Type I. Both primary and permanent teeth affected equally.
• Shields Type III : quite rare, demonstrates teeth with a shell-like appearance and multiple pulp exposures.Seen exclusively in a triracial isolated group in Maryland known as the Brandywine population.

Amelogenesis imperfecta :

• It is one of the major defects of enamel.
• It is a hereditary disease characterized by faulty development of the enamel.
• There is normal pulpal and root morphology.
• There are four major categories according to the stages of tooth development in which each is thought to occur.
• Hypoplastic Type : occur in the histodifferentiation stage of tooth development. There is an insufficient quantity of enamel formed due to areas of the enamel organ that are devoid of inner enamel epithelium, causing a lack of cell differentiation into ameloblasts. Affects both primary and permanent dentitions. The affected teeth appear small with open contacts; clinical crowns contain very thin or nonexistent enamel.
• Hypomaturation Type : defect in enamel matrix apposition and is characterized by teeth having normal enamel thickness but a low value of radiodensity and mineral content.
• Hypoplastic or Hypomaturation Type with Taurodontism : is an example of inherited defects in both apposition and histodifferentiation stages in enamel formation. The enamel appears mottled with a yellow-brown color and is pitted on the facial surfaces. Molar teeth demonstrate taurodontism.
• Hypocalcification Type : is an example of inherited defect in the calcification stage of enamel formation. Quantitatively, the enamel is normal, but qualitatively, the matrix is poorly calcified. The enamel is soft and fragile and is easily fractured., exposing the underlying dentin, which produces an unesthetic appearance.

Q2. _________ is a process in which a single tooth germ splits or shows an attempt at splitting to form two completely or partially separated crowns.

1. concrescence
2. gemination
3. fusion
4. dens in dente

Answer Key : gemination

Gemination

• It is a process in which a single tooth germ splits or shows an attempt at splitting to form two completely or partially separated crowns.
• This process results in incomplete formation of two teeth. Like fusion, it is also more common in the primary dentition.
• It results in a bifid crown with a single pulp chamber.
• It most frequently occurs in the incisor region.

Concrescence 

• It is a twinning anomaly involving the union of two teeth by cementum only. Its etiology is thought to be trauma or adjacent tooth malposition.

Dens-in-dente :

• The term dens-in-dente (also called dens invaginatus) means a “tooth within a tooth” and results from the invagination of the inner enamel epithelium.
• Most frequently involves the maxillary lateral incisors.
• The clinical significance of this anomaly results from potential carious involvement through communication of the invaginated portion of the lingual surface of the tooth with the outside environment.
• The enamel and dentin in the invaginated portion can be both defective and absent, allowing direct exposure of the pulp.

Dens evaginatus :

• It is an extra cusp, usually in the central groove or ridge of a posterior tooth and in the cingulum area of central and lateral incisors. In incisors, these cusps appear talon-shaped.

• It results from the evagination of inner enamel epithelial cells.
• This extra portion contains not only enamel but also dentin and pulp tissue; therefore, care must be taken with any operative procedure.

Fusion : 

• It is a condition produced when two tooth buds are joined together during development and appear as a macrodont (a single large crown).
• It is more common in the primary dentition.
• It may involve the entire length of two teeth (enamel, dentin, and cementum) or just the root (dentin and cementum).
• This condition is usually seen in the incisor area. Although fused teeth can contain two separate pulp chambers, many appear as large bifid crowns with one chamber. 
• Note : A radiograph is needed to confirm whether there is fusion or gemination.
• Important Notes :

2. Taurodont teeth are characterized by a significantly elongated pulp chamber with short stunted roots resulting from the failure of the proper level of horizontal invagination of Hertwig epithelial root sheath.
3. Dilaceration refers to an abnormal bend of the root during its development; it is thought to result from a traumatic episode, usually to the primary dentition. It is a consistent finding in children with congenital ichthyosis.

Q3. What condition is depicted below?

1. enamel hypoplasia
2. erythroblastosis fetalis
3. nursing bottle caries
4. dentinal dysplasia

Answer Key: Enamel hypoplasia

Enamel hypoplasia (EH):

• It is a defect in tooth enamel that results in less quantity of enamel than normal.
• The defect can be a small pit or dent in the tooth or can be so widespread that the entire tooth is small and/or misshaped. 
• This type of defect may cause tooth sensitivity, may be unsightly, or may be more susceptible to dental cavities.
• Some genetic disorders cause all the teeth to have enamel hypoplasia.
• EH can occur on any tooth or on multiple teeth.
• It can appear white, yellow, or brownish in color with a rough or pitted surface.
• In some cases, the quality of the enamel is affected as well as the quantity.

Environmental and genetic factors that interfere with tooth formation are thought to be responsible for EH.

Environmental factors:

• Severe infections such as exanthematous diseases and fever-producing disorders particularly during the first year of life. Syphilis (caused by Treponema pallidum) produces classic patterns of hypoplasia including Hutchinson incisors and mulberry molars. Rubella embryopathy has a high correlation with prenatal enamel hypoplasia in the primary dentition.
• Neurologic defects as seen in children with cerebral palsy and Sturge-Weber syndrome
• Fluorosis: excess ingestion of systemic fluoride
• Nutritional deficiencies: particularly vitamins A, C, and D, along with calcium and phosphorus
• Other: children born prematurely and children who have received excess radiation exposure as well as children with asthma

*** Causes of enamel hypoplasia affecting individual teeth include local infection, local trauma, iatrogenic surgery as seen in cleft plate closure, and primary tooth overretention. Turner hypoplasia is a classic example of hypoplastic defects in permanent teeth resulting from local infection or trauma to the primary precursor.

Genetic factors: amelogenesis imperfecta 

Treatment options :

• Depend on the severity of the EH on a particular tooth and the symptoms associated with it. 
• The most conservative treatment consists of bonding a tooth-colored material to the tooth to protect it from further wear or sensitivity. In some cases, the nature of the enamel prevents formation of an acceptable bond.
• Less conservative treatment options, but frequently necessary, include use of stainless steel crowns, permanent cast crowns, or extraction of affected teeth and replacement with a bridge or implant.

Q4. Excessive fluoride levels in drinking water are associated with fluorosis. Fluoride levels in excess of begin to pose a risk for fluorosis.

1. one part per million
2. two parts per million
3. three parts per million
4. four parts per million

Answer Key: three parts per million

• The role of fluoride in caries prevention is a very important one. Indeed, one of the most significant contributions of world’s free enterprise systems to the health of people is to market fluoridated toothpaste.
• Huge reductions in caries prevalence have been made in the populations of numerous countries where fluoridated toothpastes are used regularly.
• One major reason for the decrease in decay rates is that, because low concentrations of fluoride are present in people’s mouths, the use of fluoridated toothpaste is very effective in the remineralization of demineralized teeth.
• For example, more than ninety 9 0 % of the toothpastes sold in the United States contain fluoride. This amounts to a massive public health undertaking by the private sector.
• The significant impact on decay rates demonstrates the importance of fluoride in caries prevention.
• The mechanism of action for fluoride in caries abatement is shown in the following list:

• Increased resistance of the tooth structure to demineralization.
• Enhanced remineralization of early carious lesions.
• Impaired cariogenic activity of dental plaque, through disruption of bacterial metabolism and function.

• The studies and surveys link fluorosis to three factors:

• Fluorosis is more common in geographic areas where the endemic levels of fluoride in the drinking water are higher than three parts per million
• Fluorosis is associated with fluoride supplementation at inappropriately high levels
• The use of fluoridated toothpaste has been implicated in fluorosis

• Important: Excessive fluoride levels in drinking water are associated with fluorosis. Fluoride levels in excess of three parts per million begin to pose a risk for fluorosis. This has been demonstrated in numerous studies over decades of research and in various geographic settings around the world.

• Remember: 

• Dentin Dysplasia is another group of inherited dentin disorders resulting in characteristic features involving the circumpulpal dentin and root morphology.
• Two types:

• Shields Type I:

• Normal primary and permanent crown morphology with an amber translucency. 
• The roots tend to be short and sharply constricted.
• Primary and permanent dentitions demonstrate multiple radiolucencies and absent pulp chambers.

• Shields Type II: 
• Primary teeth are amber-colored closely resembling dentinogenesis Type I and II.
• Permanent teeth are normal in appearance but radiographically demonstrate thistle- tube-shaped pulp chambers with multiple pulp stones.
• No periapical radiolucencies are seen.

Q5. _________is the bedrock strategy on which all of pediatric dental behavior management rests.

1. tell-show-do (TSD)
2. positive reinforcement
3. Distraction
4. nonverbal communication

Answer Key : Tell-Show-Do (TSD)

TSD : 

• Child patients usually will not know what to expect during dental appointments and many will be at an age when they have considerable fears of the unknown. The TSD strategy is designed to deal with those issues.

– This approach is the backbone of the educational phase of developing an accepting, relaxed child dental patient.

– The effectiveness of the TSD approach depends on using language the child can understand. This means that we must use words or anecdotes that are age-appropriate so the child can conceptualize the idea we are trying to convey.

– Many children are helped by watching procedures done on themselves in the mirror during the procedure.It is important to provide an explanation of what is occurring as the procedure continues.

– Many children tend to be fearful of the unknown, especially in clinical situations. Being able to watch the procedure in the handheld mirror seems to diffuse anxiety.

– This approach works especially well when treating a child with a different cultural background.

• Important : 

The clinical examination of the infant and toddler should be accomplished with the parents’ assistance in a nonthreatening environment. Most often, it is neither necessary nor recommended that the dental chair be used. The parent and dentist sit facing each other in a knee-to-knee position, supporting the child with the head cradled on the dentist’s lap.

• Remember:
• Aggressive behavior in the dental office is usually a fear reaction
• The most realistic approach to managing a difficult child in the dental office is to attempt to recondition the child through techniques of applied psychology

Aversive conditioning :

• It is a form of behavior training or modification in which a noxious event is used to punish or extinguish undesirable behavior. Examples include HOME, voice control, etc.
• Most pediatric dentistry graduate programs do not teach HOME (hand-over-mouth excercise), as an acceptable behavior management technique. HOME is contraindicated in children who are unable to understand due to age, disability, medications, or emotional immaturity.
• Should always be followed by positive reinforcement (i.e., patient praise, use of tokens or “stickers,”etc.) for improved behaviors
• Need parents consent if using HOME or any aversive conditioning technique