Atypical clefts, craniosynostosis, craniofacial dysostoses Flashcards
What is the american cleft palate association classification of craniofacial congenital anomalies?
- Clefts, encephaloceles, dysostoses
- Atrophy/Hypoplasia
- Neoplasm/Hyperplasia
- Craniosynostosis
- Unclassified
Describe the theories of pathogenesis of craniofacial clefts
- Failure of Fusion (Dursy, His)
- failure of fusion of embryonic facial processes along planes of fusion
- Failure of Penetration (Stark, Johnson)
- normally NCC derived mesoderm penetrates the laminar disc of ectoderm; struture formation and maintence of ectoderms requires penetration
- therefore incomplete (partial cleft) or complete failure to penetrate can result in facial cleft
- Ischemic Theory (McKenzie, Craig)
- intrauterine vascular event and subsequent breakdown of tissue
what are treatment goals or considerations for atypical facial cleft?
- Identify areas that require urgent or early intervention
- airway compromise, swallowing compromise, increased ICP, corneal exposure
- Functional correction of macrostomia
- Functional eyelid reconstruction to permit lid closure, prevent corneal exposure
- Separate confluent cavities (orbital, nasomaxillary, oral)
- Cosmetic: correct aesthetic deformities
What are “cleftogens”?
- factors that contribute to or are associated w/ the occurance of facial clefts:
- radiation
- maternal disorders: DM, PKU
- Maternal infections: toxoplasmosis, CMV, rubella
- chemicals: Vit A admin; other vitamin deficiency
what are clinical features of aytpical cleft 0/14?
bifid nose, median cleft lip, cyclopia, hypotelorism (vs hypertelorism)
what are atypical clefts potentially associated w/ hypertelorism?
- atypical clefts 14, 13, 12
what atypical clefts are potentially associated w/ coloboma of eye?
- lower coloboma: 3,4,5,6
- upper coloboma: 11, 10, 9
what is the most common atypical cleft and its features
- most common atypical cleft is #7
- also associated w/ treacher collins syndrome (in isolation or w/ 6, and 8)
- associated w/ macrostomia, ear malformations, mandible & zygoma aplasia/hypoplasia (and therefore corresponding abnormalities to orbit)
what is frontonasal dysplasia? what is the suspected etiology? is it characterized by excess tissue or deficient tissue?
· Aka median cleft face syndrome, Tessier number 0-14 cleft
· Excess tissue – frontonasal dysplasia
· Lack of tissue – holoprosencephaly (failure of division of forebrain division into lobes)
· Etiology – embryologic arrest of development in the nasal capsule and a lack of fusion of the midface region
· Inheritance: sporadic
what is craniofacial microsomia? (define)
constellation of asymmetric craniofacial anomalies of derivatives of the 1st and 2nd branchial arches
what is a suspected etiology of craniofacial microsomia
- sporadic with no genetic transmission
- suspected 2’ to hematoma of the embryologic (and transient) stapedial artery; vs. other (teratogens)
how would you define the clinical features of craniofacial microsomia
Describe (& classify) features using the OMENS system (mulliken) plus acknowledge other associations
Orbit
- O1 – abnormal size
- O2 – abnormal position
- O3 – abnormal size and position
Other skeletal
- Mx reduced 3 dimensions
- Zygoma reduced all 3 planes; short/absent arch
- Temporal, frontal, cervical vertebrae
Mandible (Pruzansky)
- M1 – hypoplastic mandible condyle, ramus
- M2 – Short, abnormally shaped ramus
- M2a – condyle seated in glenoid fossa
- M2b – condyle (TMJ) medially displaced
- M3 – absent ramus, condyle, glenoid fossa (TMJ)
Other mandible
- Occlusal cant, anterior open bite
- Chin deviation to ipsilateral side
- Reduced alveolar height
- CL/P, CP (15%), VPI
Ear (Meurman)
- E1 – hypoplastic and cupping; all components present
- E2 – vertical remnant cartilage/skin; absent EAC
- E3 – malpositioned lobule and auricle
Nerve
- N1 – Upper facial nerve involvement
- N2 – Lower facial nerve involvement
- N3 – all branches affected
- Plus other extra-skeletal features:*
- Cardiac, CNS, pulmonary, GI, renal, MR
Soft tissue
- S1 – mild/minimal soft tissue deformity
- S2 – moderate soft tissue deformity
- S3 – severe soft tissue deformity
Other soft tissue
- Hypoplastic muscle of mastication
- Skin tag
- Soft tissue features of clefts (ex macrostomia)
what are the general management (treatment) considerations for craniofacial microsomia?
- Birth: airway, feeding, consultations, workup for associated anomalies (in particular heart, lung, GI/GU, cervico-vertebral)
- 1st year: pre-auricular skin tags, macrostomia, hearing assessment/aids
- early childhood: mandibular distraction (zygoma) (if not required urgently for airway)
- mid-childhood: costochondral graft to mandible, orthodontics
- late childhood: ear reconstruction
- adolescence: soft tissue augmentation/reconstruction; orthognathic surgery
what are specific treatment goals of craniofacial microsomia?
· Orbit – supraorbital rim/lateral orbital wall advancement; increased orbital volume
· Mandible – I/IIa à orthodontics/orthognathic, IIB/III à costochondral grafts (III often need double jaw + genio)
· Maxilla – Can show “catch up” growth after mandible is lengthened; may require LeFort I
· Zygoma – bone graft vs allograft PRN
· Ear – soft tissue à fat graft/fillers à free flap (see microtia seminar), +/- hearing aids
· Soft Tissues – fat grafting, fillers, free flap
· Oropharyngeal – CP repair, pharyngoplasty/macrostomia repair
what is treacher collins syndrome (define)
- congenital craniofacial malformation that symmetrically involves the soft tissues and skeleton of the mid and lower face
what are ways to distinguish treacher collins from unilateral or bilateral craniofacial microsomia?
- TCS is SYMMETRICALLY bilateral; whereas CFM is bilateral only 10-30% and even then it is asymmetrically bilateral
- TCS has a Familial inheritance pattern (AD w/ variable penetrance) vs. sporadic in CFM
- gene testing (TCOF1 gene on chromosome 5)
what are the characteristic features of treacher collins syndrome?
- Zygoma; absent/hypoplastic
- Mx: hypoplastic in 3 dimensions, diminished posteiror vertical height, convex face
- Md: hypoplastic in vertical and sagittal dimensions; malocclusion; occlusal cant; anterior open bite; macrostomia, retruded chin with increased vertical height
- orbit: coloboma (jxn mid/lat 1/3), medial 1/3 absent eyelids, downsloping palpebral fissure (antimongoloid slant), lower lid vertical deficiency
- Ear: microtia, Low lying hairline @ ears
- bilaterally symmetrical - defining feature
what is the inheritance pattern of TCS?
- 60% sporadic
- AD w/ variable penetrance
what are the definging features of orbital involvement in TCS
- coloboma (jxn mid and lateral 1/3)
- vertical lower lid deficiency
- medial 1/3 absent eyelashes
- downloping palpebral fissure (antimongoloid slant)
describe goals of treatment in TCS:
- to harmonize facial appearance
- To close/correct coloboma and vertical lower lid deficiency
- To reconstruct malar/zygomatic promence and arch
- To restore maxillo-mandibular relationship and occlusion
- To reconstruct auricle and macrostomia
Describe how you would approach the treatment of TCS
- Emergencies & early intervensions (newborn)
- airway considerations (usual protocol for PRS including consideration of early DO)
- feeding considerations (NG/g-tube; remember choanal atresia)
- eyelid intervention for corneal exposure (temporary vs. permanent)
- consultations
- hearing assessments
- “O-Z-M-C” intervensions (~ 2-4yrs):
- palpebral & coloboma repair +/- lateral canthopexy
- early skeletal interventions: NVBG, VBG, alloplastic, DO
- macrostomia repair
- microtia recon (consider the skin flap required and the low hair line, esp prior to major mandibular procedures to preserve skin/STA)
- Mandible interventions:
- Pruzansky I/IIA: orthognathic later in life / Pruzansky IIA/IIB – DO / Pruzansky III – costochrondral rib graft
- Many patients require orthognathic double jaw surgery later in life (Lefort I + BSSO)
o Other – Ear reconstruction, facial profile (rhino, genio, malar/cheek augmentation)
what is a sequence, compared to a syndrome?
- a sequence is a series of events that occur secondary to a specific inciting event
- a syndrome is a collection of findings across different systems that occur in response to a genetic abnormality
how do you define pierre robin sequence?
- retrognathia
- glossopthosis
- airway compromise
- with 50% association with U-shaped cleft palate
- in response to the inciting event of mandibular hypoplasia, then the tongue does not descend, may then cause the lateral palatine processes to fail to fuse (CP) and all contributing to airway obstruction
what syndromes are associated w/ pierre robin sequence?
- 20% PRS is syndromic
- Stickler is most common
- others include: Mobeius, Beckwith Weideman, TCS, Nager, q22
what is the natural history of PRS?
- for non-syndromic patients, the retrognathia/microgenia will often catch up, and at that point any concern regarding airway obstruction usually resolves
- left still with permanent microgenia/retrognathia though which may rquire orthognatic internveion in future
- for syndromic patients with other intrinsic characteristics that predispose to airway obstruction or restricted growth, this natural progression is not observed
what consulations would you want to get for PRS?
- genetics, social work, nutrition, PRS, ENT, ophthomology, audiology, SLP
what are some considerations for treatment / extent of treatment / indication for intervention?
- duration and severity of desaturation
- response to conservative measures
- duration of high end tidal CO2
- FTT despite o2 supplementation and nutrition intervention
describe interventions (in order) utilized for patients wiht airway obstruction and PRS
- monitoring +/- supplementation oxygen
- prone position (lateral)
- nasopharyngeal tube
- feeding interventions
- tongue-lip adhesion
- tracheostomy
- distraction osteogeneis
- (last 2 may be interchangable depending on context, urgency etc)
besides airway, what is the other urgent consideration for patients w/ PRS. How is this typically managed?
- other consideration is feeding /FTT
- daily weights, nutrition consultation
- haberman nipple
- anti-reflux meds
- consideration of NG, g-tube
after the initial period in hospital managing airway and feeding concerns, what are the longer term concerns for patient w PRS?
- when to repair CP - usually delayed @ around 18-24 mos
- management of micrognathia in long term usually at skeletal maturity with chin augmentation/genioplasty/orthognathic surgery w/ BSSO vs. double-jaw
what are complications of untreated airway obstruction in infacnts w PRS?
if untreated: OSA, cor pulmonale, hypoxia, FTT – mortality rate 14-19%
ensure all infants get sleep studies
what is moebius syndrome?
- congenital bilateral absence of cranial nerve VII