Chapter 1: Developmental Defects Flashcards
Orofacial
clefts
-‐ CL=45%; CL+CP=30% (etiologically related); CPO=25%; 30% of CL ± CP and 50% CPO syndromic
-‐ Asians have highest prevalence of orofacial clefts. Majority of CL are unilateral, left side.
-‐ Environmental risks: mom smoking/drinking, folic acid def, corticoids or anticonvulsants use
-‐ Lateral facial cleft (from commissure to ear): associated with Treacher Collins, hemifacial microsomia, Nager acrofacial dysostosis and amniotic rupture sequence
-‐ Oblique facial cleft (upper lip to eye): assoc w/ CP
-‐ Median cleft of upper lip: associated with oral-‐facial-‐digital syndrome and Ellis van Crevelde
-‐ Bifid uvula: minimal manifestation of CP
-‐ Submucous palatal cleft: affects muscle only, with surface mucosa intact
-‐ Pierre-‐Robin: CP, mandibular micrognathia, glossoptosis (airway obstruction caused by posterior displacement of tongue). Assoc w/ Stickler and velocardiofacial syndrome. SOX9/KCNJ2 genes.
-‐ DiGeorge’s sydrome: Absent or hypoplastic thymus, defective cellular immunity and tetany.
CATCH-‐22 (Cardiac anomaly, Abnormal fascies, Thymic aplasia, Cleft palate and Hypocalcemia/Hypoparathyroidism), Chr 22 abnormality.
Commissural lip pits
-‐ Small mucosal invaginations at corners of mouth on vermillion border
-‐ Pts have higher prevalence of preauricular pits (aural sinuses)
Paramedian lip pits
-‐ Invaginations on lower lip. Seen in 3 syndromes:
-‐ Van der Woude syndrome: CL ± CP. Most common cause of syndromic clefting. IRF-‐6 mutation.
-‐ Popliteal pteryigium syndrome: CL ± CP, popliteal pterygia (webbing behind knee), genital abnormalities and syngnathia (connection upper and lower jaw). IRF-‐6 mutation
-‐ Kabuki syndrome: CL ± CP, eversion of eyelids, mental retardation, joint laxity, skeletal abnormalities, large ears and hypodontia
Bifid tongue
-‐ Complete or incomplete (deep furrow along midline dorsum or double ending at tip of tongue)
-‐ Orofacial digital syndrome: bifid tongue, multiple hyperplastic frenula (upper/lower)
Double lip
-‐ Redundant fold of tissue on mucosal side of lip
-‐ Ascher syndrome: double lip, upper eyelids edema (blepharochalasis), non-‐toxic thryroid enlargement (thyrotoxocosis)
Leukoedema
-‐ Also see in vagina, larynx, FOM, labial mucosa and palatal pharyngeal tissues
Microglossia
-‐ Oromandibular-‐limb hypogenesis syndromes: microglossia, hypodactylia (absence of digits) and hypomelia (hypoplasia of limbs)
-‐ Microglossia can be associated with hypoplasia of mandible and lower incisors may be missing
Macroglossia (specifically Beckwith-Wiedemann)
-‐ Beckwith-‐Wiedemann syndrome: macroglossia, omphalocele, visceromegaly, visceral tumors (Wilms’, adrenal ca), gigantism and neonatal hypoglycemia. Chr 11 defect.
-‐ Facial: port wine stain, earlobe indentations and posterior ear pit, and maxillary hypoplasia.
Macroglossia causes
Congenital vs Acquired
Congenital and Hereditary
-Vascular malformations
-Lymphangioma
-Hemangioma
-Hemi hyperplasia
-Cretinisn-l
-Beckwith-Wiedemann syndrome
-Down syndrome
-Duchenne muscular dystrophy
-Mucopolysaccharidoses
-Neurofibromatosis type I
-Multiple endocrine neoplasia, type 2B
Acquired
-Edentulous patients
-Amyloidosis
-Myxedema
-Acromegaty
-Angioedema
-Wasthenia gravis
-Amyotrophic återal sclerosis
-Carcinoma ard other tumors
Lingual thyroid
-‐ Ectopic thyroid tissue. 90% found in foramen ceccum region.
-‐ 4-‐7x more in females. In 70% of the cases, it’s pts’ only thyroid tissue (avoid removal)
-‐ 30% have hypothyroidism (lingual thyroid is compensatory?).
-‐ 75% of patients with infantile hypothyroidism have some ectopic thyroid tissue
-‐ Dx: thyroid scan (avoid biopsy: hemorrhage and may be pt’s only thyroid tissue).
-‐ No tx required, but 1% develop into malignancy (more common in males)
Fordyce granules
50-‐90x increase in Lynch syndrome (hereditary nonpolyposis colorectal cancer syndrome)
Fissured tongue
-‐ Strong association with geographic tongue
-‐ Melkerson-‐Rosenthal syndrome: fissured tongue, facial paralysis, lip swelling
Hairy tongue
-‐ Keratin accumulation on filliform papillae
-‐ Causes: tobacco, poor OH, debilitation, antibiotics and radiotherapy
-‐ Coated tongue: accumulation of bacteria and epithelial cells, w/o hairlike filliform projections
Black hairy tongue cause
Bismuth
Likely Pepto bismol
Varicosities
-‐ Most common type is subligual varix
-‐ Isolated varices: lips and buccal mucosa. Typically noticed after thrombosis
-‐ Lines of Zahn: layered zones of platelets and RBC in thrombosed varix
-‐ Phlebolith: dystrophic calcification of a thrombus
Caliber-‐persistent artery
-‐ Main arterial branch extends up w/o reducing diameter
-‐ Due to loss of tone? Appears as a papule on lip, w/ pulsation.
Developmental cysts
Lateral soft palate fistula
-‐ Bilateral on anterior tonsilar pilar.
-‐ Can appear following infection, surgery, or as a result of a developmental defect
-‐ Few cases assoc w/ absence of tonsil, hearing loss and preauricular fistulas
Coronoid hyperplasia
-‐ Usually bilateral growth of coronoid process. 5x more in males.
-‐ Unilateral: must differentiate from true tumor (osteoma or osteochondroma)
-‐ Mouth opening limitation or deviation of MD to the affected side (unilateral); opening limitation (bilateral)
Condylar hyperplasia
-‐ Excessive growth of one of the condyles. Causes facial asymmetry, prognathism, open/cross bite
– Deviation towards the contra lateral side
– Significant female predilection (F:M 3:1)
-‐ DDx: hemifacial hyperplasia (has soft tissue and teeth involvement)
Condylar hypoplasia
-‐ Congenital: Treacher Collins, Goldenhar syndrome (oculo-‐auriculo-‐vertebral syndrome) and hemifacial microsomia. Complete aplasia may be seen.
-‐ Acquired: usually trauma. Also infections, RT, and arthritis
-‐ X-‐ray: short condylar process, shallow sigmoid notch and small condyle head
-‐ Goldenhar: incomplete development of the ear, nose, soft palate, lip, and mandible. Limbal dermoids, preauricular skin tags, and strabismus.
Bifid condyle
Double-‐headed condyle. Due to trauma, abnormal muscle attachment, teratogenic agents or persistence of fibrous tissue within condylar cartilage
Exostoses
-‐ Types: buccal (facial MD or MX), palatal tubercle (lingual MX tuberosity), solitary (due to irriation, such as graft placement), and reactive subpontine (under post bridge)
-‐ Reactive subpontine exostosis: beneath a posterior bridge in the alveolar bone.
Radiographically, may closely resemble an osteoma
Torus
-‐ Palatinus: Morphologic classification: Flat, spindle, nodular, lobular
-‐ Mandibularis: bilateral in 90% of cases. Correlation with bruxism and # remaining teeth
Eagle syndrome
-‐ Symptomatic elongation of styloid process or calcification of the stylohyoid ligament.
-‐ Types: classic (after tonsillectomy), carotid artery/stylohyoid syndrome (carotid is compressed by process) or traumatic (fracture of calcified ligament)
Stafne defect (static bone cyst)
-‐ RL in angle of MD below canal between molars
-‐ Focal concavity of lingual mandible, usually containing sub-‐MD gland tissue
-‐ Rarely in ant MD (sublingual gland) and upper ramus (parotid gland)
-‐ 80-‐90% men
Developmental cysts
Palatal cysts of the newborn
-‐ Epstein’s pearls (median palatal raphae); Bohn’s nodules (scattered all over palate).
-‐ Origin: epithelium entrapment when shelves fuse or epithelial remnants from MSG, respectively
Developmental cysts
Nasolabial cyst (Klestadt’s cyst)
-‐ Adults
– Origin: nasolacrimal duct?
-‐ Swelling of upper lip lateral to midline, elevation of nose ala. Obliteration of the mucolabial fold.
–No radiographic changes are seen because arise in soft tissue
-‐ Histo: pseudoestratifed columnar epithelium, can have cilia and goblet cells and apocrine lining
Developmental cysts
Nasopalatine duct cyst
– Adults (4th-6th decades), rarely before 1st decade
-‐ Most common non-‐odontogenic cyst of mouth. Arises from remnants of the nasopalatine duct
-‐ Canals of Scarpa: foramina within the incisive foramen that carry the nasopalatine nerves
-‐ Organ of Jacobson: accessory olfactory organ in some animals
-In humans, Jacobson’s organ usually recedes in uterine life => vestigial structure
-‐ Incisive canal or cyst? If > 6 mm, consider a cyst (unless others symptoms are present)
-‐ Cyst of incisive papilla: ST nasopalatine duct cyst
-‐ X-‐ray: inverted pear shape between maxillary incisors
-‐ Lining: squamous (75%), columnar, cuboidal or mixed + canal contents (nerves and arteries)
Developmental cysts
Median palatal cyst
-‐ Posteriorly positioned nasopalatine duct cyst?
-‐ Dx criteria: clinical enlargement; midine location; posterior to palatine papilla; ovoid or round xray; teeth vital; no communication with incisive canal; no nerves, vessels, cartilage, or MSG in the wall.
Developmental cysts
Follicular cysts of the skin
-‐ Epidermal cyst (80%): aka infundibular cyst. Associated with Gardner syndrome
-‐ Epidermal inclusion cyst: traumatic implantation of epithelium
-‐ Pilar cyst (15%): aka tricholemmal or isthmus-‐catagen cyst. No granular layer, compact keratin
–Milia (singular: milium) = tiny keratin-filled cysts that resemble miniature epidermoid cysts
Developmental cysts
Dermoid cyst
-‐ Benign cystic form of teratoma
-‐ Complex teratoma: composed of all 3 layers. More in ovaries or testes; benign or malignant.
-‐ Immature teratoma (malignant): contains primitive neuroepithelium
-‐ Neonates have benign teratomas and adults have malignant
-‐ Oral teratomas (epignathus): usually congenital and extend through a cleft palate from pituitary via Rathke’s pouch. High mortality associated with airway obstruction.
-‐ Heterotopic oral gastrointestinal cyst (enterocystoma): oral cyst lined with GI epithelium. Most in FOM and tongue. Considered a choristoma (normal tissue in abnormal location)
-‐ Dermoid cysts: contain dermal appendages in wall (if no appendages are present -‐> epidermoid)
Developmental cysts
Thyroglossal duct cyst
-‐ Midline neck, 60-‐80% below hyoid bone (often attached). Can be clinically identified by vertical movement during swallowing. Usually children or young adults.
– Most often lined by respiratory epi
-‐ Sistrunk procedure: removal of thyroglossal duct cyst with hyoid bone and muscle
-‐ 1% can transform into papillary thyroid carcinoma
Developmental cysts
Branchial cleft cyst (cervical lymphoepithelial cyst)
-‐ 95% from 2nd branchial arch.
-‐ Upper lateral neck anterior to SCM
- Infra or postauricular (per Dr. Turk)
– Most frequently develop in children and young adults between ages of 10 - 40
Bimodal presentation (< 5 years; 20-40 years) (expertpath)
-‐ If patient is older, check if lining is malignant to r/o cystic metastatic SCC
Developmental cysts
Oral lymphoepithelial cyst
–Middle-aged adults (4th-6th decade, per Woo and ExpertPath)
–Small submucosal mass, usually less than 1cm
-‐ Waldeyer’s ring: palatine tonsils, lingual tonsils and pharyngeal adenoids
-‐ Floor of mouth most frequent location.
–Presence of lymphoid tissue in cyst wall = most striking feature
Hemihyperplasia (hemihypertrophy)
-‐ Asymmetric growth of 1 or more body parts.
-‐ Complex (entire side of the body) or simple (single limb).
-‐ Isolated (most) or associated with: Neurofibromatosis, Mc-‐Cune Albright, Maffucci, segmental odontomaxillary dysplasia, Beckwith-‐Wiedemann syndrome and Proteus syndrome.
-‐ Skin: increased pigmentation, hypetrichosis, telangiectasias, nevus flammeus
-‐ Increased prevalence of abdominal tumors (Wilms’, adrenal ca and hepatoblastoma)
-‐ Hemifacial hyperplasia: confined to one side de of the face, difficult to distinguish from “condylar hyperplasia” Assoc w/ premature eruption
Progressive hemifacial atrophy (Parry-‐Romberg syndrome)
-‐ Atrophy of one side of face, pigmentation, enopthalmos and delayed eruption of teeth
-‐ Associated with trauma and Lyme disease (Borrelia infection).
-‐ Starts on skin (pigmentation), then nerves and bones.
-‐ Closely related to localized (linear) scleroderma (also has en coupe de sabre-‐ scar on forehead)
Mouth and nose are deviated toward affected side
○ Atrophy of upper lip may expose maxillary teeth
○ Unilateral atrophy of tongue
Unilateral open bite often develops as result of mandibular hypoplasia and delayed eruption of teeth
Segmental odontomaxillary dysplasia
(hemimaxillofacial dysplasia)
-‐ Painless, unilateral enlargement of MX + fibrous hyperplasia of overlying gingiva
-‐ Absence of 1+ MX PM, hypoplastic primary teeth
-‐ Xray: vertically oriented and thickened bony trabeculae (granular appearance)
-‐ DDx with fibrous dysplasia, hemifacial hyperplasia and fibrous developmental malformation
-‐ Becker’s nevus: hypertrichosis and hyperpigmentation (one case assoc with SOD)
– fibrous hyperplasia of overlying gingival soft tissues
– Maxillary sinus smaller on the affected side
-‐ Histo: ST-‐ fibrosis; bone-‐ irregular trabeculae with woven appearance and reversal lines
Crouzon syndrome
(craniofacial dysostosis)
-‐ FGFR2 mutation. Related to increased paternal age
-‐ Characterized by craniosynostosis: premature closing of cranial structures
-‐ Brachycephaly (short head), scaphocephaly (boat-‐shaped head), trigonocephaly (triangle shape) or** clover leaf skull (Kleeblattschadel deformity)**
-‐ Radiograph: beaten-‐metal pattern (increased digital markings)
-‐ HN: midfacial hypoplasia, ocular proptosis, teeth crowding and midline maxillary pseudocleft
-‐ Visual and hearing loss, no mental retardation
Apert syndrome (acrocephalosyndactyly)
-‐ AD, FGFR2 mutation. Related to increased paternal age
-‐ Acrobrachycephaly (tower skull), tall appearance of forehead, clover leaf skull (Kleeblattschadel deformity), visual loss
-‐ Syndactyly of hand and feet: distinguishes Apert from other craniosynostosis syndromes
-‐ Radiograph: beaten-‐metal pattern
-‐ Oral: “open-‐mouth” appearance, trapezoid lips, cleft soft palate/bifid uvula, lateral hard palate swelling with pseudocleft (hyaluronic acid deposition), shovel-‐shaped incisors
Treacher Collins syndrome (mandibulofacial dysotosis)
-‐ Related to increased paternal age.
-‐ TCOF1 (treacle) gene mutation (chr 5)
-‐ Facies: hypoplastic zygoma, narrow face, depressed cheeks and downward palpebral fissures
-‐ Coloboma: notch in outer lower eyelid seen in Treacher Collins (no eyelashes medial to it)
