Chapter 1: Developmental Defects Flashcards
upper lip formation occurs at weeks ___
6-7
upper lip formation involves the merging of what processes?
medial nasal processes merge with each other as well as the maxillary processes of the first branchial arches
when does central face development begin?
at week 4
medial and lateral ___ develop from the proliferation of ___ on both sides of each nasal placode
- nasal processes
- ectomesenchyme
the primary palate consists of a merger of what?
medial nasal process
the secondary palate is formed from the ___ on the ___
- maxillary processes
- first branchial arches
the ___ palate makes up 90% of the hard and soft palates
secondary
a cleft lip is the defective fusion of the ___ process with the ___ process
medial nasal process with the maxillary process
most (80%) of cleft lip cases are bilateral or unilateral?
unilateral
when can you treat for cleft lip?
- rule of 10 - 10 weeks, 10 lbs, 10 gm %hemoglobin
cleft palate is a result of the failure of what to fuse?
the palatal shelves
the minimal manifestation of cleft palate is ___
bifid uvula
about what patient age is treatment of celft palate usually performed?
1.5yrs
what are the relative prevalences of developmental cases that are CP only, CL only, or CL + CP?
- CL + CP - 45% (most common developmental case)
- 30% CP only
- 25% CL only
what are the relative prevalences of syndromic clefting?
- 30% of patients with CL + CP
- 50% of patients with syndromic cleft palate only (CPO)
what is pierre robin sequence?
- CP
- mandibular micrognathia
- glossoptosis (downward displacement)
what are environmental factors responsible for nonsyndromic clefting?
- maternal alcohol or cigarette use
- folic acid deficiency
- corticosteroid use
- anticonvulsant therapy
what is the likelihood that a person affected with nonsyndromic clefting will have offspring or siblings who are also affected?
5%
the lateral facial cleft results from the lack of fusion of the ___ and ___ processes. it accounts for ___% of all facial celfts
- maxillary and mandibular processes
- <0.5%
an oblique facial cleft results from the failure of fusion of the ___ with the ___; it extends from the ___ to the ___, and is almost always associated with ___
- lateral nasal processes with the maxillary process
- upper lip to the eye
- CP
a median cleft of the upper lip results from the failure of fusion of the ___ processes; is it common or rare?
- medial nasal processes
- it is very rare
___ are one of the most common major congenital defects
orofacial celfts
what is the prevalence of orofacial clefts among asians, native americans, african americans, and caucasians?
- native americans
- asians
- caucasians
- african americans
is CL + CP more common in males or females?
males
the more severe the defect, the greater the male predilection
is CPO (cleft palate only) more common in males or females?
females
the more severe the defect, the greater the female predilection
what is a submucous palatal cleft?
- appears as a bluish midline discoloration
- surface is intact, but defect exists in the underlying musculature of the soft palate
- a bone notch will be present on the posterior hard palate margin
___ are mucosal invaginations that occur at the corners of the mouth on the vermillion border
commissural lip pits
are commissural lip pits associated with facial or palatal clefts? what is the treatment?
neither, and no treatment is required
___ are congenital invaginations of the lower lip
paramedian lip pits
are paramedian lip pits usually unilaterally or bilaterally located? what is the treatment?
- bilaterally located
- no treatment except evaluate for syndrome (or for esthetics)
___ syndrome is the greatest significance of paramedian lip pits
van der Woude syndrome
describe van der Woude syndrome
- autosomal dominant
- CL + CP
- paramedian lip pits
- most common form of syndromic clefting (2% of all CL + CP)
what is a double lip?
redundant fold of tissue on mucosal side of lip
what does a double lip result from?
congenital or acquired (trauma or oral habits)
is a double lip more common on the upper or lower lip?
upper > lower
a double lip is only noticeable when the patient does what?
tenses lip (smile)
what is the treatment for a double lip?
no treatment except for esthetics
what is ascher syndrome?
- double lip (usually acquired)
- blepharochalasis (eyelid edema)
- nontoxic thyroid enlargement
fordyce granules are ___ sebaceous glands
ectopic
fordyce granules are present in ___% of the population
80% (this is actually a variation of normal)
fordyce granules clinically appear as ___
yellow or yellow-white papular lesions
what are the most common locations of fordyce granules?
buccal mucosa and lateral portion of vermillion of uper lip
are fordyce granules more common in adults or children?
adults; puberty appears to stimulate development
what is the treatment for fordyce granules?
no treatment required
leukoedema affects up to ___% of african american adults and ___% of african american children
90% and 50%
why is leukoedema more prevalent in the african american population?
likely because background mucosal pigmentation in african americans makes the edematous changes more noticeable
is leukoedema a variation of normal?
yes
what does leukoedema look like clinically?
- typically appears as diffuse, gray-white, milky, opalescent lesions found bilaterally on buccal mucosa
- does not rub off
- white appearance disappears when cheek is stretched = clinical diagnosis
what is the treatment for leukoedema?
no treatment
___ is the term for an abnormally small tongue
microglossia
is microglossia syndromic or nonsyndromic?
usually syndromic
syndromic microglossia usually has what associated limb features?
- hypodactylia (absence of digits)
- hypomelia (hypoplasia of part of all of a limb)
- rarely, the entire tongue may be missing
what is the term for a missing tongue?
aglossia
aglossia is frequently associated with ___, and ___ may be missing
- hypoplasia of the mandible (micrognathia)
- lower incisors may be missing
what is the treatment of aglossia?
depends on nature and severity of condition
what is the term for an abnormally large tongue?
macroglossia
macroglossia is most frequently caused by what?
- vascular malformations
- muscular hypertrophy
- other etiologies - lymphangioma, down syndrome, amyloidosis, angioedema, tumors
macroglossia is most common in what population?
children
what condition may be manifested by noisy breathing, drooling, and difficulty in eating or speaking?
macroglossia
severe cases of macroglossia can cause ___
airway obstruction
what is beckwith-wiedmann syndrome?
- macroglossia is a characteristic of the syndrome
- patients have increased risk for several childhood tumors
- most cases are sporadic
what is the treatment for macroglossia?
depends on cause and severity of condition
what is described as a developmental tongue abnormality characterized by a short, thick lingual frenum resulting in limitation of tongue movement?
ankyloglossia (aka tongue-tied)
akyloglossia is seen in up to ___% of neonates
4%
what is the male:female ratio of the prevalence of ankyloglossia?
4:1
M:F
in other words, it is 4x more common in males than females
___ may cause problems with speech and breastfeeding
ankyloglossia
what is the treatment for ankyloglossia?
- no treatment required if asymptomatic; condition could be self-correcting
- frenectomy or frenuloplasty otherwise - wait until age 4-5
describe a lingual thyroid
- thyroid gland begins as an epithelial proliferation in the floor of the pharyngeal gut during week 3-4 of embryogenesis
- during week 7, the thyroid bud normally descends into the neck - located at the junction of the anterior 2/3 and posterior 1/3 of the tongue in midline
- if primitive gland doesn’t descend normally, ectopic thyroid can be found between the foramen cecum and the epiglottis - 90% of ectopic thyroids are found here
lingual thyroids are more common in males or females?
up to 7x more common in females
in ___% of cases, lingual thyroids are the patients only thyroid tissue
70%
what are the symptoms of lingual thyroid?
- arise during puberty, adolescence, pregnancy, or menopause
- dysphagia, dysphonia, dyspnea
- presents as a nodule on posterior tongue at the midline
1/3 of patients with lingual thyroid have ___
- hypothyroidism
- lingual thyroid enlargement may be secondary to compensate for thyroid hypofunction
how is a lingual thyroid diagnosed?
thyroid scan (using iodine isotopes or technetium-99m), CT, and/or MRI
why is a biopsy not indicated to diagnose a lingual thyroid?
risk of hemorrhage and may be patients only functioning thyroid tissue
describe a fissured tongue
- aka scrotal tongue
- tongue exhibits multiple grooves/furrows on dorsal tongue
what is the prevalence of fissured tongue in children and adults?
up to 5% of children and 30% of adults
grooves in a fissured tongue can measure from ___-___ in depth
2-6mm
what is the cause of fissured tongue?
unknown cause
is fissured tongue usually symptomatic?
no, it is usually asymptomatic, but there can be possible mild burning
fissured tongue has a strong association with ___
geographic tongue
fissured tongue is a component of ___ syndrome
melkersson-rosenthal
what is the treatment for fissured tongue?
no treatment except to brush the tongue
benign migratory glossitis and erythema migrans are other terms for ___
geographic tongue
is geographic tongue developmental?
no
geographic tongue is a common ___ condition
inflammatory
what is the female:male ratio of the prevalence of geographic tongue?
2: 1
female: male