Tuesday, April 30, 2013

Dentinogenesis Imperfecta


Syndrome: Dentinogenesis Imperfecta
- anomaly of structure - histodifferentiation
- heritable defect of predentin matrix
- normal mantle dentin
- amorphic and atubular circumpulpal dentin
- 1:8000
- Autosomal dominant

Three Types:
1. DI Shields Type I
            - occurs with osteogenesis imperfecta type
            - primary teeth more severely affected
            - permanent teeth most affected – central incisors and 1st molars
            - amber translucence
            - periapical radiolucencies
            - bulbous crowns, obliteration of pulp chambers, root fractures
            - rapid attrition of teeth




2. DI Shield Type II
            - occurs alone – no OI-“hereditrary opalescent dentin”
            - both dentitions affected equally
            - same characteristics of DI-I
            - irregular or tubular pattern
            - rapid attrition


 3. DI Shields Type III
            - rare – Brandywine population only (triracial isolated group in Maryland)
            - bell-shaped crowns
            - shell teeth with short roots and enlarged pulp chambers
            - multiple pulp exposures
            - regular tubules
            - enamel pitting
            - different expression for the same DI-II gene

Dentin Dysplasia


Syndrome: Dentin Dysplasia
- anomaly of structure - apposition
- characterized by presence of normal enamel but atypical dentin with abnormal pulpal morphology
- 1:100,000

Two Types:
1. Shields Type I Dentin Dysplasia = radicular dentin dysplasia
            - normal color of crown of primary and permanent teeth
            - short, blunted roots or rootless in both dentitions
            - obliterated pulp chambers
            - periapical radiolucencies
            - cascading of dentinal tubules in root
            - can be normal tubule orientation in coronal of normal dentin
            - root sheath problem
            - severe mobility and malalignment
            - autosomal dominant
- normal dentinal tubule formation is blocked and new dentin forms around obstacles - known as lava flowing around boulders





2. Shields Type II Dentin Dysplasia = Coronal Dentin Dysplasia
            - primary teeth affected
            - coronal dentin is involved as well as root dentin
            - amber colored primary teeth
- permanent teeth look normal, but radiographically demonstrate thistle-tube shaped pulps and multiple pulp stones



De Lange Syndrome

De Lange Syndrome
 

Incidence: Approximately 1:10,000 live births

Etiology: believed to be caused by a gene mutation. Common charachteristics include low birth weight (under 5lbs), slow growth, small stature, small head size, thin eyebrows which often meet in the midline, long eyelashes, short upturned nose and thin downturned lips, excessive body hair, small hands and feet, partial joining of the second and third toes, incurved fifth fingers, missing limbs or portion of limbs, usually fingers, hands or forearms.

Common medical problems include: GERD, seizures, heart defects, cleft palate, bowel abnormalities, feeding difficulties, and developmental delay, mental retardation ranging from mild to profound. (most are mild to moderate)
Absent or minimal speech has been noted in most children but it is clear that all do communicate. The ability to speak for most individuals is much more difficult than the ability to comprehend language.
Mild to moderate hearing loss or even severe hearing loss is in almost all children with this syndrome.
Strabismus (misalignment of the eye), nystagmus (shaky eyes), nearsightedness, ptosis (drooping of one or both eyelids) are commonly seen in patients with de Lange syndrome. Also, blepharitis is seen in 50% of patients and manifests as recurrent red eyes, crusting on the eyelashes, itchy eyes, tearing, or eye discharge, due to suboptimal flow in the eyelid.

Dental considerations: These patients tend to have small jaws, poor OH, crowded teeth, small teeth, perio dz, and erosion of teeth due to GERD. Cleft palate is common and should be repaired as soon as possible to help improve speech, reduce ear infections leading to hearing loss, and improve the ability to eat.

Cardiac considerations:  20-30% have congenital heart disease ranging from mild to severe defects. All patients who are diagnosed with this syndrome should be evaluated by a cardiologist.

Behavior:  Patients may be described as being hypersensitive; having strong reactions to ordinary stimiuli that last long after the stimulus is removed. Patients may also be described as being disrhythmic; irregular behavior in eating, sleeping and emotional response.

Beckwith Wiedemann Syndrome

Beckwith Wiedemann Syndrome


Etiology: Congenital overgrowth disorder that is caused by a sporadic genetic mutation in 85% of cases. Genetics are complex, but chromosome 11 has been implicated as the problem area. BWS remains a clinical diagnosis because physicians cannot identify and test for all the genetic causes of BWS.
Five common features used to define BWS are: macroglossia (large tongue), macrosomia (birth weight and length >90th percentile), midline abdominal wall defects (omphalocele-intestines, liver, other organs remain outside the abdomen in a sac b/c of defect in abdominal wall muscles, umbilical hernia, diastasis recti-separation of rectus abdominis muscles into right/left halves), ear creases or ear pits, and neonatal hypoglycemia (low blood sugar after birth).

Diagnosis: Patients normally don’t present with all 5 features. Child is considered to have the syndrome if it has been diagnosed by a physician and they present with at least 2 of the 5 major features.
Systemic/Medical Conditions: Patients have higher risk of developing cancer, although 80% do not. Most common tumors are Wilms’ tumor (nephroblastoma) and hepatoblastoma. Both can usually be cured if diagnosed early.

Oral Manifestations: Macroglossia (one of the five principal features)
Dental needs/considerations: Macroglossia in BWS becomes less noticeable with age and often requires no treatment; but it does cause problems for some patients. In severe cases, macroglossia can cause respiratory, feeding, and speech difficulties. Children with BWS and significant macroglossia should be evaluated by a craniofacial team. Early orthodontic intervention can halt problems before they progress (open bite, mouth breathing, protrusion of teeth)
The best time to perform surgery for a large tongue is not known. Some surgeons recommend performing the surgery between 3 and 6 months of age. Surgery for macroglossia involves removing a small part of the tongue so that it fits within the mouth to allow for proper jaw and tooth development.

Tuesday, April 23, 2013

Cri-du-chat Syndrome


Syndrome: Cri-du-chat Syndrome
- AKA chromosome5p deletion syndrome, 5p minus syndrome or Lejeune’s syndrome
- chromosomal condition that results when a piece of chromosome 5 is missing
- 1 in 20,000 to 50,000 newborns
- gets its name from the characteristic cry of affected infants, which is similar to that of a meowing kitten, due to problems with the larynx and nervous system

Etiology:
- due to a partial deletion of the short arm of chromosome number 5, also called "5p monosomy".
- Approximately 90% of cases result from a sporadic, or randomly occurring deletion.
- The remaining 10-15% are due to unequal segregation of a parental balanced translocation where the 5p monosomy is often accompanied by a trisomic portion of the genome.

Diagnosis:
Diagnosis is based on the distinctive cry and accompanying physical problems

Systemic/Medical Conditions:
- intellectual disability and delayed development
- behavioral problems such as hyperactivity, aggression, tantrums, and repetitive movements
- small head size (microcephaly),
- low birth weight
- weak muscle tone (hypotonia) in infancy
- widely set eyes (hypertelorism),
- low-set ears
- rounded face


 
Oral Manifestations:
- Micrognathia
- Excessive drooling
- Feeding problems due to problems sucking and swallowing
- Cleft lip and palate
- Severe Class II malocclusion

Dental needs/considerations:
- Treatment of cleft lip and palate if present
- An aggressive preventive dentistry program is essential
- Behavior management
- Orthodontics

References
Boraz RA. Cri-du-chat syndrome: dental considerations and report of case. Spec Care Dentist. 1990 Jan-Feb;10(1):13-5.

Ehlers-Danlos Syndrome



Syndrome: Ehlers-Danlos Syndrome
- a group of inherited connective tissue disorders, caused by a defect in the synthesis of collagen (Type I or III)
- Affects 1:10,000 to 1:150,000 people

Etiology:
- X-linked
- Caused by mutations in the following:
-Fibrous Proteins: COL1A1, COL1A2, COL3A1, COL5A1, COL5A2, and TNXB
-Enzymes: ADAMTS2, PLOD1, B4GALT7

Diagnosis:
A diagnosis can be made by an evaluation of medical history and clinical observation. The Beighton scale is widely used to assess the degree of joint hypermobility. Both DNA and biochemical studies can be used to help identify affected individuals. Diagnostic tests include: collagen gene mutation testing, collagen typing via skin biopsy, echocardiogram, and lysyl hydroxylase or oxidase activity.

Systemic/Medical Conditions:
- Hyperplastic, fragile skin and mucosa
- Skin hemorrhages and scars
- Joint hypermobility



Oral Manifestations:
- Irregular dentinal tubules with inclusions
- Intrapulpal calcifications
- Mucosa is thin and tears easily.
- Sutures will not hold.
- Perio disease develops quickly and aggressively.
- Hypoplastic enamel is common as are small teeth and blunted roots.
- Tongue is usually large and palate is vaulted

Dental needs/considerations:
- Short appointments to minimize strain on TMJ.
- Small amount of anesthetic to avoid hematoma.
- Light ortho forces and frequent perio recall are recommended.

References
- LĂ©tourneau Y, PĂ©russe R, Buithieu H. Oral Manifestations of Ehlers Danlos Syndrome. Journal of the Canadian Dental Association 2001; 67:330-4
- Nowak, AJ and Casamassimo PS. The Handbook of Pediatric Dentistry. 4th Edition. 

Fanconi Syndrome

Fanconi Syndrome

Overview: This is a disease of the proximal renal tubules in which glucose, amino acids, uric acid, phosphate and bicarbonate are passed into the urine, instead of being reabsorbed.

 
Etiology:
This syndrome may be inherited or caused by drugs or heavy metals.

Diagnosis:
-Cystinosis is the most common cause of Fanconi syndrome in children.
- Other recognized causes are Wilson's disease (a genetically inherited condition of copper metabolism), Lowe syndrome, tyrosinemia (type I),[5] galactosemia, glycogen storage diseases, and hereditary fructose intolerance.

Clinical Features:

The clinical features of proximal renal tubular acidosis are:


Other features of the generalized proximal tubular dysfunction of the Fanconi syndrome are:


Dental Findings:
- Enamel hypoplasia

Tx:
- Treatment of children with Fanconi syndrome mainly consists of replacement of substances lost in the urine (mainly fluid and bicarbonate).

Marfan Syndrome

Marfan Syndrome:


Definition: Marfan Syndrome is an autosomal dominant disorder of the connective tissue. Marfan Syndrome features can occur in many different parts of the body.

Etiology: Defects in a gene called fibrillin-1. Majority of the cases are genetic, however, up to 30% of cases have no family history.

Frequency: About 1 in 5,000.

Clinical Features: Long, thin arms and legs, scoliosis and arachnodactyly. Arm span is much greater than their height. A chest that sinks in or sticks out -- funnel chest or pigeon breast. Flat feet, hypotonia, hyperflexible joints, learning disabilities, severe myopia or dislocation of the lens of the eye, aortic dilation or aortic aneurysm, heart valve problems, or collapsed lung.

Oral Manifestations: Long, narrow face, high palatal vault, prominent lower jaw, crowding and malocclusion.

Treatment: Vision problems should be treated when possible. Treatment of scoliosis in adolescence, medication to slow the heart rate may help prevent stress on the aorta, avoiding participating in competitive and contact sports to avoid injuring the heart. Some people may need surgical replacement of the aortic root and valve.

Prognosis: Heart-related complications may shorten the lifespan of people with this disease. However, many patients survive well into their 60s. Good care and surgery may extend the lifespan further.

Dental Considerations: Antibiotic prophylaxis and orthodontic care.

Sturge-Weber syndrome

 
Definition: Sturge-Weber Syndrome (encephelotrigeminal angiomatosis) is a congenital, non-familial hamartomatous vescular proliferation mainly involving areas along the trigeminal nerve distribution.

Etiology: Not clear, but is thought to be caused by the presence of a vascular plexus around the portion of the neural tube destined to become the facial skin.

Frequency: Rare.

Clinical Features: Hemangiomas of the skin, face, and oral mucosa, calcifications of the brain, ocular disorders such as glaucoma, epilepsy and mild mental retardation. Facial hemangiomas are the most constant and characteristic finding of this syndrome appear as a bright red or purple and are usually unilateral.


Oral Manifestations: Oral hemangiomas also tend to be unilateral, may involve the maxillary gingival, buccal mucosa, tongue and lips, are usually flat, but may have a raised irregular surface that causes tissue enlargement. Delayed or early and ectopic dental eruptions are also common.

Treatment: Depends on the location and severity of the lesions, laser therapy may lighten or remove stains. Anticonvulsants may be indicated.

Amelogenesis Imperfecta



- Amelogenesis Imperfecta (AI) may be inherited by x-linked, autosomal dominant or recessive or sporadic inheritance.  (Multiple inheritance patterns)
- AI interferes with normal enamel formation.  There is usually not an associated systemic disorder.
- Incidence between 1:4000 and 1:14000

Manifestations:  

- The 4 most common types of AI are:  hypocalficifed, hypoplastic pitted, hypoplastic generalized and hypomaturation.

- There are 14 subgroups

-  The variability of appearance of different types of AI makes identification challenging.

AI Type I (Hypoplastic) is reviewed in the AAPD handbook.  

- Insufficient quantity of enamel, with both dentitions affected.  

- Anterior open bite occurs in 60% of these patients.

 
Dental Characteristics:

- Often times children with AI will have accelerated tooth eruption or will have late eruption

- Associated pathologies are enlarged follicles, impacted permanent teeth and ectopic eruption

- Agenesis of second molars has been observed

- More uncommonly, enamel resorption and ankylosis have been reported

- Anterior open bite is common in 50% of those with hypoplastic AI, 31% in hypomaturation AI, and 60% in hypocalcified AI

Tx:

- Teeth may need to be treated with full coverage SSC

- Some teeth may need to extracted
 
 


 
 

Williams Syndrome


Williams Syndrome

Resident: Mackenzie Craik

Seen in 1/7500 births, present at birth, occurs in all ethnicities and effects males and females equally. 

- Small upturned nose, long philtrum, wide mouth, full lips, small chin, puffiness around the eyes. Blue and green eyed children have a starburst ( a white lacy pattern on the iris)

- Most have heart or blood vessel problems such as narrowing of the aorta or pulmonary arteries, which can range from trival or severe, and cause an increased risk for high blood pressure.

- Young children can have elevated levels of blood calcium causing extreme irritability or colic-like symptoms

- Most children have low-birth weight and slow weight gain 

- Feeding problems due to low muscle tone, severe gag reflex, poor suck/swallow, tactile defensiveness etc. May resolve as the children get older.

- Slightly small, widely spaced teeth are common. They also may have a variety of abnormalities of occlusion, tooth shape or appearance.

- Increased incidence of problems with kidney structure and/or function

- Inguinal (groin) and umbilical hernias are more common

- More sensitive hearing than other children; Certain frequencies or noise levels can be painful an/or startling, often this improves with age. (patient may be sensitive to the sound of the high speed) Young children often have low muscle tone and joint laxity. Joint stiffness may develop as children get older

- These children tend to have an excessively social personality. They are typically unafraid of strangers, extremely polite and show a greater interest in contact with adults than with their peers.

- Some degree of intellectual handicap. Young children with often experience developmental delays; milestones such as walking, talking and toilet training are often achieved somewhat later than is considered normal. Strengths and weaknesses are often seen in older children and adults. There are some intellectual areas (such as speech, long term memory, and social skills) in which performance is quite strong, while other intellectual areas (such as fine motor and spatial relations) are significantly deficient.

- Anesthesia concerns are the patient's cardiovascular system, kidney function, airway anatomy, metabolic status, joint mobility and level of cognitive functioning. A cardiologic evaluation within the 12 months preceding surgery is desirable and records from the cardiologist should be requested for the anesthesiologists review. Copies of EKG'S, echocardiograms, chest x-rays (if available) and cardiac catheterizations (if appropriate) should be provided. The airway problems in WS concern the potential difficulty in placing an endotracheal tube for general anesthesia in the WS individual with an underdeveloped lower jaw. Dental problems, including brittle or loose teeth can compound this difficulty. These features are best noted when the anesthesiologist performs a brief, specific physical exam during the preoperative visit.


Hurlers Syndrome


Hurlers Syndrome Review

Resident: Mackenzie Craik

Hurler Syndrome: Also known as mucopolysaccharidosis. Genetic disorder that results in the buildup of glycosaminoglycans.

Etiology: Results in the buildup of glycosaminoglycans due to a deficiency of alpha-L iduronidase. A buildup of heparin sulfate and dermatan sulfate occurs. Occurs in 1:25,000 births.

Diagnosis: Prenatal diagnosis with amniocentesis and chorionic villus sampling can verify if a fetus either carries a copy of the defective gene or is affected with the disorder. After birth of a child clinical examination and urine tests are used.

Systemic/medical conditions associated: Progressive deterioration, hepatosplenomegaly, dwarfism and unique facial features. Mental retardation is progressive with death occurring by age 10. Language may be limited due to hearing loss and enlarged tongue. Corneas become clouded and retinas begin to degenerate. Carpal tunnel syndrome and restricted joint movement is common. Children may be large at birth with hernias. Many children slow in growth after age three develop a short body trunk and grow to less than 4 feet. Facial features include flat face, depressed nasal bridge and bulging forehead. Liver spleen and heart are often enlarged. Feeding often difficult and many children die early from obstructive airway disease, respiratory infections or cardiac complications.

Oral manifestations: Facial manifestations: Monitor for obstructive airway when performing dental treatment.

Dental needs: Prevention and often and early treatments to prevent stressful and lengthy appointments.

Recent information: Gene therapy has gained much interest. Patients are given retroviral, lentiviral, AAV and even nonviral vectors to deliver the iduronidase gene. This treatment has been successful on mice, dogs and cat models.


Wednesday, April 17, 2013

Vitamin D Resistant Rickets


Vitamin D Resistant Rickets

Resident: Mackenzie Craik

Vitamin D Resistant Rickets' Vitamin D-resistant rickets is considered a metabolic disorder whose symptoms originate from the age of one with limb deformities and decreased growth. Males are more often affected than females. Vitamin-D Resistant Ricketts can be differentiated from other forms of rickets by family history (is X-linked), normal serum calcium, and marked hypophosphatemia.

Main characteristics: short stature, hypophosphatemia, Bones can be painful, soft, and pliable. Patients have bow legs and skeletal abnormalities.

Etiology: The cause of Vitamin-D Resistant Rickets is related to a selective abnormality in renal phosphate transport resulting in hyperphosphaturia and hypophosphatemia. In hypophosphatemic Vitamin D-resistant rickets (renal rickets) the renal tubules can't resorb phosphorous/control he amount of phosphate excreted in the urine. Hypophosphatemic rickets is caused by low levels of phosphate.

Dental Manifestations: Dentin Abnormalities, * Delayed Primary exfoliation/Delayed Eruption of Permanent Teeth, * Premature Exfoliation of Teeth,. Enamel Defects are not associated with Vitamin D-Resistant Rickets. Also associated with the condition: hypomineralized dentin, increased width to predentin, odontoblastic disorganization (odontodysplasia), decreased alkaline phosphatase activity in tooth germ, and enlarged pulp and pulp horns. Very importantly, there have been "Spontaneous" dental abscesses resulting in pulp infection through abnormally mineralized (interglobular) dentin (Seow, Kim BDS, AAPD Journal, 1991) have also been noted clinically. These teeth did not have a history of caries.

Treatment: is generally through nutritional supplements of phosphate and calcitriol (the activated form of vitamin D)

Dental Treatment: Early dental treatment/prevention is necessary to prevent spontaneous pulp death in primary and permanent teeth.(As a side note for the boards: it is probably good to keep in mind that Vitamin D-resistant rickets, hyperparathyroidism, and pseudo-hyperparathyroidism are all conditions demonstrating characteristic dentinal abnormalities.)




Apert Syndrome


Apert Syndrome

by Mackenzie Craik

Etiology: Apert Syndrome is a congenital, hereditary, autosomal dominant condition that originates from the first branchial arch. Mutations in a gene called fibroblast growth factor receptor 2 causes bony sutures to close too early, causing craniosynostosis.

Diagnosis: Genetic Testing is used to confirm Apert Syndrome. Physical examination, hand, foot and skull radiographs, and hearing tests are common.
Patients with Apert Syndrome have Craniofacial Anomalies* and may suffer from mental retardation, hearing deficit, respiration problems, and acne vulgaris (when a teenager). They often require multiple surgeries to correct abnormal bone growth.

Main Features: The main features of Apert Syndrome are *Craniosynostosis, *Symmetric Syndactyly of the hands and feet, and midfacial malformations. Deformities in Apert Syndrome are symmetric.

Craniofacial Features Include: *Shallow Orbits/Ocular Hypertelorism, Ocular Proptosis, Divergent Strabismus, *Parrot (Beaked) Nose, Hypoplastic and Retruded Midface, Depressed Nasal Bridge, and Low Set Ears

Dental Manifestations: *Hyperdontia, *Delayed Primary Exfoliation/Delayed Permanent Eruption, *Cleft palate is highly associated (board review book says “30% cleft palate”), *V-shaped maxilla, *Severe Dental Crowding, *Anterior Open bite, *Class II Malocclusion (Board review book says “Class III with open bite”), Supernumerary Teeth, and Lateral Palatal Swellings

Dental Treatment: Interdisciplinary treatment—dental, orthodontic, oral/maxillofacial treatment is all typically necessary. There is also often the need for supplementary prophylactic dental intervention.