Developmental Flashcards
When does development of the face begin?
End of 4 weeks
What are the five prominences that forms the face?
1 central frontonasal promience
2 paired maxillary prominences
2 paired mandibular prominences
What are the two subdivisions of the central frontonasal prominence?
2 medial nasal processes
2 lateral nasal processes
What causes cleft lip?
Defective fusion of median nasal processes with maxillary processes
What causes cleft palate?
Defective fusion of the palatal shelves
What are thought to be etiologically related conditions? What is a separate entity?
CL and CL+CP; CP
What is the most common major congenital defect in humans?
Orofacial clefts
What puts a patient at increased risk for orofacial clefts?
Maternal alcohol use, cigarette smoking, and anticonvulsant therapy (particularly phenytoin)
What are possible prevention techniques to prevent orofacial clefts?
Folic acid supplementation
Cleft Lip +/- Cleft Palate: Frequency in Population
Native American Population: 3.6 in 1000 births
Asian Population: 1.5x higher than white population
Black Population: 0.4 in 1000 births
Cleft Lip and CL+CP are more common in what sex?
Males
Where do 70% of unilateral CL occur?
Left side
Cleft Palate Only: Range in severity
May involve hard and soft palate or soft palate only
Cleft Palate Only: What is a minimal manifestation?
Cleft/bifid uvula
Cleft Palate Only: Frequency in Populations
1:80 white individuals
Up to 1:10 asian and native american individuals
Cleft uvula only in 1:250 Black Individuals
Cleft Palate Only: More common in what sex?
Females
What are four rare cleft patterns?
Lateral/Transverse Facial Cleft, Oblique facial cleft, median cleft of the upper lip, and submucous palatal cleft
Describe why a lateral/tranverse facial cleft occurs
Defect in fusion of maxillary and mandibular processes
What specific syndrome do lateral/transverse facial clefts occur with?
Mandibulofacial dysostosis (Treacher Collins Syndrome)
Oblique Facial Cleft: Describe
Cleft extends from upper lip to the eye
Oblique Facial Cleft is always associated with cleft ____
Cleft palate
What happens if an oblique facial cleft is severe?
Incompatible with life
Median Cleft of the Upper Lip: Describe what occurs
Defect in fusion of the medial nasal processes
Submucous Palatal Cleft: Describe
Cleft of the underlying musculature of the soft palate and often a midline palatal bone notch along posterior hard palate.
With a submucous palatal cleft, the overlying mucosa is _____
Intact
Submucous Palatal Cleft: Presentation
Bluish midline discoloration
How is the submucous palatal cleft identified
By palpation
What does the submucous palatal cleft often present with?
Cleft uvula
Define Association
A group of malformations that occur together more than would be expected by chance alone
Define syndrome
A recognizable pattern of signs or symptoms that run together
How does syndrome differ from association
Typically differs from association in that a molecular cause has been discovered
Define Sequence
A pattern of deformations and malformations which is a consequence of a single malformation.
Pierre Robin Sequence: Describe this sequence’s presentation with its three characteristics
- Cleft Palate
- Mandibular micrognathia
- Glossoptosis
How can Pierre Robin Sequence occur?
May occur as an associate finding or as part of a syndrome (DiGeorge Syndrome)
Pierre Robin Syndrome: Describe known sequence of events
Underdevelopment of the jaw -> Tongue displacement/failure to descend -> prevention of fusion of the palatal shelves with resultant cleft palate (or high-vaulted, U-shaped palate in mild cases)
Pierre Robin Sequence: Clinical Outcomes
-Respiratory, feeding and speech difficulty
-Malocclusion
-Possible missing teeth, supernumerary teeth
Other names for Deletion 22q11.2 syndrome
DiGeorge syndrome and velocardial facial syndrome
Deletion 22q11.2 Syndrome: Cause
Syndrome caused by deletion of a small portion of chromosome 22
Deletion 22q11.2 Syndrome: Clinical features
Heart defects
Poor immune system function
Characteristic facial features
Cleft palate
Delayed development with behavioral and emotional problems
Low calcium levels
Deletion 22q11.2 syndrome: Characteristic facial features
Underdeveloped chin, low-set ears, wide-set eyes or a narrow groove in the upper lip
Acronym for Deletion 22q11.2 syndrome:
CATCH 22:
Cardiac Defect
Abnormal facies
T-Cell deficit
Cleft Palate
Hypocalcemia
Mandibulofacial Dysostosis (Treacher Collins Syndrome): Etiology
Defects of structures derived from 1st and 2nd branchial arches
Mandibulofacial Dysostosis: Inheritance pattern
Autosomal dominant inheritance
Mandibulofacial Dysostosis: Clinical features tend to _____ with subsequent generations in the same family
Worsen
Mandibulofacial Dysostosis: Associated with ______ paternal age
Increased
Mandibulofacial Dysostosis: Clinical features (Characteristic facies)
Hypoplastic zygomas
Narrow face
Depressed cheeks
Downward slanting of palperbral fissures
Mandibulofacial Dysostosis: Effect on ears
Ear deformities and conductive hearing loss
Mandibulofacial Dysostosis: Effect on mandible
Underdeveloped causing retruded chin
Mandibulofacial Cleft: 15% have lateral facial clefting resulting in ___
Macrostomia
Cleft palate appears in how many mandibulofacial dysostosis patients?
15%
How are parotid glands affected in mandibulofacial dysostosis?
Hypoplastic or even absent parotid glands
Mandibulofacial Dysostosis: Radiology
Hypoplasia condyle and coronoid processes
Prominent antegonial notching
Mandibulofacial Dysostosis: Treatment
Depending on severity:
-If breathing is compromised patient may need trachetomy
-Orthognathic surgery
-Orthodontic treatment
Two types of lip pits
Commissural Lip Pits & Paramedian Lip Pits
Commissural Lip Pits: Describe
Small mucosal invaginations at the corners of the mouth on the vermilion border
Commissural Lip Pits: Population affected
M>F
Commissural Lip Pits: How far can these blind fistulas extend to?
Depth of 1 to 4 mm
What type of pits are more prevalent with commissural lip pits?
Preauricular pits
Commissural lip pits are not associated with what two conditions?
Facial or palatal clefts
Commissural Lip Pits: Tx if they get infected
Excision
Commissural Lip Pits are _____ associated with syndromes
NOT
Paramedian Lip Pits: Describe location
Typically bilateral and symmetrical fistulas of the lower lips
Paramedian Lip Pits range from
Subtle depressions to prominent humps
Paramedian Lip Pits can extend down to ____ cm
1.5 cm
What are paramedian lip pits associated with?
Clefting Syndromes such as Van Der Woude Syndrome, Popliteal Pterygium Syndrome and Kabuki Syndrome
What is the most common syndromic form of clefting?
Van Der Woude Syndrome
Double Lip Etiology
May be congenital or acquired
Double Lip Congenital Cause
Arises during second or third month of gestation
Double Lip Acquired Cause
Component of Ascher Syndrome or a result of trauma or oral habits
What is affected in double lip
Can affect either or both lips (most commonly upper lip)
Cause of Ascher Syndrome
Unknown, may be inherited AD
Onset of symptoms of Ascher Syndrome
Around time of puberty
Three characteristic components of Ascher Syndrome
Double Lip
Blepharochalasis
Non-toxic thryoid enlargement
What does blepharochalasis occur abruptly and spontaneously with?
Double Lip
Microglossia: Define
Uncommon developmental condition characterized by abnormally small tongue
Microglossia Cause
Unknown
Microglossia What do most cases occur as part of?
Oromandibular limb hypogenesis syndrome
Microglossia is frequently associated with
Hypoplasia of the mandible and possible lower incisors missing
Macroglossia is an uncommon characterized by
Enlargement of the tongue
Macrglossia is caused by
A wide variety of conditions both congenital malformations and acquired disease
Lymphangioma: Define
Benign, hamartomatous tumorlike growths of lymphatic vessels
Lymphatic malformations have a marked predilection for what area of the body?
Head and neck
Lymphangioma: When are lesions found?
Half of all lesions are noted at birth, and around 90% develop by 2 years of age
Lymphangioma: What are the three classifications
- Macrocystic (cystic hygroma) >2cm cyst like spaces
- Microcystic
- Mixed
What do Macrocystic (cystic hygroma) present as?
Soft, fluctuant mass
Lymphangioma: Describe oral lesions and where they present
-Most frequent in anterior 2/3 of tongue
-Usually microcystic type: pebbly surface that resembles a cluster of translucent vesicles (Frog egg or tapioca appearance)
How is Lymphangioma diagnosed
Appearance is clinically diagnostic in most cases (does not require biopsy)
How are small lesions of lymphangioma treated
Not treated unless esthetic concern
How are large lesions of lymphangioma treated
large lesions may cause airway compromise in case of cystic hygroma -> percutaneous schlerotherapy or other surgical intervention and supportive care
Ankyloglossia: Describe cause
Tissue attaching to floor of mouth during development does not properly undergo degeneration
Ankyloglossia: Clinical Appearance
Short/thickened frenum resulting in limited tongue movement
Ankyloglossia: How does this condition affect infants and adults
Infants: May cause difficulty nursing, failure to gain weight and thrive in infants
Adults: May cause speech difficulty in adults
Ankyloglossia: Treatment
Laser or surgical incision to release tie
Typically reserved only for patients with functional complaints
Lingual Thyroid Other Names
-Ectopic Thyroid
-Aberrant Thyroid Tissue
Lingual Thyroid: Etiology
-Normally the thyroid descends into the neck during development -> 7th week gestation
-Site where the descending thyroid bud comes from foramen cecum (junction of the anterior 2/3 and posterior 1/3 of tongue)
Where is 90% of ectopic thyroid tissue found?
Between foramen cecum and epiglottis
How many lingual thyroids are asymptomatic thyroid remnants at the posterior dorsal tongue?
10 percent
Describe Symptomatic Cases of lingual thyroid
4-7x more common in females.
Symptoms frequently start in puberty, pregnancy, menopause
70% of the time it is the patients only thyroid tissue
Hypothyroidism in 33% of patients
Lingual Thyroid: How do we diagnose?
Avoid Biopsy in most/all cases
Scan with iodine isotopes or technetium-99m (concentrates at thyroid tissue)
Lingual Thyroid: What can a biopsy cause?
Biopsy of lingual thyroid will cause significant bleeding and this tissue may be the patient’s only functioning thyroid tissue
Treatment for Asymptomatic Lingual Thyroid
No treatment indicated
Treatment for symptomatic lingual thyroid
Supplemental thyroid hormone may shrink it, ablative therapy, transplantation
Malignancy develops in how many cases of lingual thyroid
one percent
Describe how often lingual thyroids occur in different sexes
More lingual thyroids in females but less frequently malignant than in males
Describe treatment for males with lingual thyroids
Some advocation for prophylactic excision of lingual thyroids in males
Coronoid Hyperplasia: Etiology
Rare developmental anomaly of unknown etiology
Coronoid Hyperplasia results in
Limitation of mandibular movement
Coronoid Hyperplasia: Population affected
3-5x more common in males
Coronoid Hyperplasia: Unilateral or bilateral? How is the mandible affected?
May be both; mandible deviates towards the affected side
Coronoid Hyperplasia: Treatment
Surgical removal of elongated coronoid process/es
Condylar Hyperplasia: Define
Uncommon malformation of the mandible created by excessive growth of one of the condyles
Condylar Hyperplasia: Etiology
Etiology unknown
Condylar Hyperplasia: Population affected
F>M 3:1
Condylar Hyperplasia: Clinical Appearance
Condylar head and/or neck may show elognation
Many cases show hyperplasia of the entire ramus
Patient may show asymmetry, prognathism, crossbite, open-bite
Unilateral cases of mandibular condylar hyperplasia shift ____ from the affected side
Away
Condylar Hyperplasia: Treatment
Self limiting process
Surgery to correct the defect if functionally compromises patient or esthetics are of concern +/- orthodontic treatment
Describe Condylar Hypoplasia
Underdevelopment of the mandibular condyle
Etiology of condylar hypoplasia
Congenital or acquired
Condylar Hypoplasia: Congenital is associate with what head and neck syndromes?
Mandibulofacial dysostosis, oculoauriculovertebral syndrome, hemifacial microsomia
Acquired Condylar Hypoplasia results from:
Disturbances in the growth center of the developing condyle
What are some causes for acquired condylar hypoplasia?
Trauma during childhood/adolescence
Infections
Radiotherapy
Degenerative arthritis
Condylar Hypoplasia: If unilateral, the mandible will shift _____ the affected side
Towards
Bifid Condyle: Etiology
Rare developmental anomaly resulting in doubleheaded mandibular condyle
What heads are affected in bifid condyle
Unilateral or bilateral?
Usually medial and lateral heads rather than anterior and posterior heads
Unilateral
Bifid Condyle: Symptoms & Treatment
Usually asymptomatic and requires no treatment
Eagle Syndrome/Carotid Artery Syndrome: Describe
Elongated stylohyoid process/mineralized complex impinges on internal or external carotid arteries and sympathetic fibers causing symptoms in the patient
Eagle Syndrome classically occurs after what procedure?
Tonsillectomy (or other neck trauma)
Describe how/if carotid artery syndrome is related to eagle syndrome
Related to eagle syndrome but distinguished by some authors as being unrelated to tonsillectomy
Population affected with eagle syndrome/carotid artery syndrome
Adults, F>M
Symptoms of eagle syndrome/carotid artery syndrome
Vague facial pain exacerbated by: chewing, swallowing, turning the head, opening the mouth
Dysphagia
Dysphonia
Headache, dizziness, syncope, transient ischemic attacks
Eagle Syndrome/Carotid Artery Syndrome: Diagnosis
Observed on PAN or lateral-jaw radiographs
Can be palpated in the tonsilar fossa area-> often elicits pain
Eagle Syndrome/Carotid Artery Syndrome Treatment
Local injection of corticosteroids may help symptoms
Surgical excision of elongated stylohyoid process in severe cases
List the three newborn anomalies that do not require treatment
Neonatal & natal teeth
Palatal cysts of the newborn
Gingival cysts of the newborn
Define natal teeth
Teeth present in newborns
Define neonatal teeth
Teeth arising within the first thirty days
More neonatal/natal teeth are ____ teeth, not supernumerary teeth
Decidous
85% of natal teeth are
Mandibular incisors
Palatal Cysts of the newborn: Describe
Small superficial keratin filled cysts
What are the two types of cysts that occur on the palate of newborns
- Epstein Pearls and bohn’s nodules
Location of epstein pearls
occur along median palatal raphe
Epstein pearls are derived from:
Entrapped epithelium during fusion of palatal shelves
Bohn’s nodules location
Scattered over the hard palate often near soft palate junction
Bohn’s nodules are derived from
Minor salivary glands
Gingival Cysts of the newborn: Describe clinical findings and location
Small, superfical, keratin-filled cysts that are found on the alveolar mucosa of infants
Gingival Cysts of the newborn: origin
Cysts are odontogenic origin
Hemifacial Hyperplasia: Etiology
Rare developmental anomaly characterized by asymmetric overgrowth
Hemifacial Hyperplasia may be associated with what syndromes?
Beckwith-widemann syndrome
Neurofibromatosis
McCune-Albright Syndrome
Progressive hemifacial atrophy is also known as
Parry-Romberg Syndrome
Describe Progressive hemifacial atrophy
Atrophic changes affecting one side of the face
Many features of progressive hemifacial atrophy are similar to
Scleroderma
Onset of progressive hemifacial atrophy occurs at what age?
First two decades of life
Describe how progressive hemifacial atrophy begins to look clinically and how it progresses
Begins as atrophy of the skin and subcutaneous structures in a localized area of the face-> spreads at variable rate -> follows a dermatome or branches of trigeminal nerve
Progressive hemifacial atrophy population
Female>Male
Clinical Features of Progressive Hemifacial Atrophy
-Overlying skin has dark pigmentation
-Linear scleroderma
-Ocular involvement ->enophthalmos
-Local alopecia
-May develop: trigeminal neuralgia, facial parasthesia, migraine, epilepsy
Segmental Odontomaxillary Dysplasia: Describe
Recently recognized developmental disorder that affects the jaws and sometimes the overlying facial tissues
Cause of segmental odontomaxillary dysplasia
Unknown
What is clinically frequently mistaken for craniofacial fibrous dysplasia or hemifacial hyperplasia?
Segmental Odontomaxillary dysplasia
Characteristics of Segmental Odontomaxillary Dysplasia
Painless, unilateral enlargement of the maxillary bone, fibrous hyperplasia of overlying gingival soft tissue
What teeth are missing with segmental odontomaxillary dysplasia
One or both developing maxillary premolars are frequently missing
Radiographic Appearance of Segmental Odontomaxillary Dysplasia
Thickened trabeculae that are vertically oriented
Radiopaque granular appearance to the bone
Treatment for segmental odontomaxillary dysplasia
Usually stabilizes and may not need any treatment, can recontour the are if necessary
Regional Odontodysplasia Cause/Etiology
Localized non-hereditary developmental abnormality
Proposed etiologies for regional odontodysplasia
Viral infection, abnormal migration of neural crest cells, trauma/infection, circulatory defect, malnutrition
What dentition can regional odontodysplasia occur in?
Primary or permanent
Regional Odontodysplasia Population affected
Slight female predominance
Jaw and teeth affected more often by regional odontodysplasia
Maxillary > Mandibular; predilection for anterior teeth
What happens to the soft tissue of the overlying affected teeth in regional odontodysplasia?
Hyperplasia
What happens to affected teeth in regional odontodysplasia?
Fail to erupt if teeth erupt appear small, irregular, yellow-brown, rough surfaced
Treatment for Regional Odontodysplasia
-Unerupted teeth should be left until skeletal growth is complete
-Erupted teeth should be covered but not prepped (easy pulp exposure)
