Embryology and Cleft

EMBRYOLOGY & CLEFT——-DANIEL W TODD, MD ARCHES—-MESODERM—DIFFERENTIATES INTO THE MUSCLES, BONE, VESSELS, AND CARTILAGE NERVE IS ANT TO ARTERY EXCEPT IN 5TH/6TH ARCH 5TH/6TH ARCH HAS NO MESODERM MANIFSET ON THE SURFACE GROOVES=CLEFTS (EXTERNAL)=ECTODERM 1ST CLEFT OR GROOVE FORMS THE EAC—2ND THROUGH 4TH CLEFTS FORM TEMPORARY CERVICAL SINUSES BUT ARE USUALLY OBLITERATED BY THE 2ND ARCH MESENCHYME (INNERVATED BY CN 7) POUCHES=(INTERNAL)=ENDODERM GENERALLY DIFFERENTIATE INTO GLANDULAR ORGANS EACH POUCH HAS A VENTRAL AND DORSAL WING THE FOURTH POUCH HAS AN ADDITIONAL ACCESSORY WING—ULTIMOBRANCHIAL BODY–BECOMES INFILTRATED WITH NEURAL CREST CELLS(APUD)—BECOME PARA OR INTERFOLLICULAR (C-CELLS) OF THE THYROID (AMYLOID STROMA) AND SECRETE TCT (MEDULLARY CA) TM IS REALLY FORMED BY ALL THREE—–GROOVE, ARCH, POUCH INCUS = LARGEST OSSICLE STAPES = SMALLEST BONE IN BODY: STAPEDIUS = SMALLEST MUSCLE IN BODY BELLY OF THE STAPEDIUS CAN LOOK LIKE THE FN PERSISTENT STAPEDIAL ARTERY = A PROBLEM DURING STAPEDECTOMY MALLEUS HAS NO BODY INCUS HAS NO HEAD STAPES HAS NO NECK INCUS—LOOKS LIKE ICE CREAM CONE ON CT SCAN LENTICULAR PROCESS OF INCUS MOST SUSCEPTIBLE TO AVN (MAX CHL= 60 DB– 6 MONTHS AFTER A STAPES) ANOMALIES: CYSTS–POCKET, NO IN OR OUT–-USUALLY FILLED WITH EPITHELIAL DEBRIS AND CHOLESTEROL SINUS–IN OR OUT FISTULA–IN AND OUT CYSTS>>>SINUSES>>FISTULAS ALL LINED WITH EITHER SQUAMOUS OR RESP EPITHELIUM ALL CONTAIN LYMPHOID AGGREGATES—CAN ACT LIKE A LN IN AN URTI MOST CONG NECK MASSES APPEAR IN THE FIRST 2 DECADES OF LIFE FNA CAN BE VERY HELPFIL IN THE DIAGNOSIS –USUALLY FILLED WITH EPITHELIAL DEBRIS AND CHOLESTEROL ALL STRUCTURES/ANOMALIES–EXIT ANT TO THE ANT BORDER OF THE SCM (EPICARDIAL RIDGE MESODERM/CERVICAL SOMITES)AND CEPHALAD/SUPERIOR/SUPERFICIAL TO THE HYPOGLOSSAL NERVE(CNXII IS CAUDAL/INF/DEEP TO ALL THE ARCHES) EXCLUDING MIDLINE NECK MASSES–BRANCHIAL CLEFT CYSTS ARE THE MOST COMMON CONG LESIONS OF THE ANT TRIANGLE MALIGNANT DEGENERATION IS RARE RECURRENCE SHOULD BE LESS THAN 5% FOLLOWING GOOD SURGERY FIRST ARCH (MANDIBULAR ARCH) MECKEL’S (MANDIBLE) CARTILAGE--MALLEUS HEAD AND NECK, INCUS BODY AND SHORT PROCESS, ANT MALLEAL LIGAMENT, SPHENOMANDIBULAR LIGAMENT, MANDIBLE MESODERM—-TENSOR TYMPANI, MUSCLES OF MASTICATION, ANT DIGASTRIC, TENSOR VELI PALATINI (FIRST 3 OF 6 AURICULAR HILLOCKS OF HIS—-TRAGUS, HELICAL ROOT AND HELIX) NERVE—-SEMILUNAR(GASSERIAN) GANGLION—V3 ARTERY DEGENERATES 1ST POUCH—MIDDLE EAR CAVITY FIRST BRANCHIAL APPARATUS ANOMALIES(1-3%) M=F PRESENT AT MEAN AGE 2.5 YEARS EXIT TO THE SKIN ANT TO THE SCM, SUP TO THE HYOID, INF TO THE MANDIBLE RUN SUPERFICIAL TO (THE GREAT VESSELS) ICA, ECA, CN IX, CN XII WORK’S TYPE I–ECTODERM ONLY—LIKE AN ACCESSORY EAC(RUNS PARALLEL TO THE EAC) SUPERFICIAL TO THE FACIAL NERVE–USUALLY—BUT STILL PRETTY DARN CLOSE WORK’S TYPE II–ECTODERM AND MESODERM—MUCH MORE COMMON RUNS PERP TO THE EAC INVOLVE THE FACIAL NERVE—-BEWARE!!!!—-USUALLY DEEP TO THE FACIAL NERVE—WAIT UNTIL AGE 2 OR MORE TO FACILITATE DISSECTION EXT. OPENING NEAR THE BC JUNCTION IN THE INF EAC OR CONCHAL BOWL OFTEN PRESENTS AS A DRAINING EAR WITH AN INTACT TM—SOMETIMES A MEMBRANOUS ATTACHMENT FROM THE TM TO THE INF EAC Rx IS TOTAL REMOVAL VIA MODIFIED POST AURICULAR INCISION (FARRIOR AND SANTINI ‘85)—-FIND THE FACIAL NERVE—VERY SUPERFISCIAL IN KIDS–MAY NEED TO DO PARTIAL SUPERFICIAL PAROTIDECTOMY
SECOND ARCH (HYOID ARCH) REICHERT’S CARTILAGE-—MANUBRIUM OF MALLEUS, INCUS LONG AND LENTICULAR PROCESS, STAPES SUPERSTRUCTURE (FOOTPLATE AND ANNULAR LIGAMENT FORM OTIC CAPSULE[MESODERM]), PYRAMIDAL EMINENCE, STYLOID PROCESS, STYLOHYOID LIGAMENT, HYOID LESSER CORNU AND UPPER BODY, LOWER HALF OF THE FACIAL CANAL MESODERM—-PLATYSMA, STAPEDIUS MUSCLE AND TENDON, MIMETIC MUSCLES, AURICULAR MUSCLES, POST DIGASTRIC, STYLOHYOID LAST 3 OF 6 AURICULAR HILLOCKS OF HIS—-ANTI HELIX, ANTI TRAGUS, AND LOBULE NERVE—-GENICULATE GANGLION AND VII ARTERY—-STAPEDIAL(USUALLY DEGENERATES) 2ND POUCH—-OPENS TO TONSILLAR FOSSA CAVEATE–THE OTIC CAPSULE (BONE) IS MESODERMALLY DERIVED WHILE THE MEMBRANOUS LABYRINTH IS ECOTODERMALLY DERIVED—–PARS SUP (POST/SUP) SCC’S AND UTRICLE ARE FIRST AND PARS INF (ANT/INF) COCHLEA AND SACCULE ARE LAST TO DEVELOPE SECOND BRANCHIAL APPARATUS ANOMALIES(95%) 4 TYPES (CYSTS>>>SINUSES > FISTULAS) SUPERIOR TONSILLAR FOSSA BETWEEN ICA(POST) AND ECA(ANT), SUPERFICIAL TO 9 AND 12, ANT TO SCM MEAN AGE 13, MALE=FEMALE, 2% BILAT THIRD ARCH CARTILAGE BAR—HYOID GREATER CORNU AND LOWER BODY—-REALLY MOST OF THE HYOID MESODERM—STYLOPHARYNGEUS AND UPPER PHARYNGEAL CONSTRICTORS NERVE—CN 9 (NERVE OF HERRING) ARTERY—COMMON AND INTERNAL CAROTID 3RD POUCH–ENDODERM—-OPENS TO PIRIFORM SINUS FORMS 3 STRUCTURES:THYMUS(VENTRAL), L AND R INF PTG(DORSAL) THIRD BRANCHIAL APPARATUS ANOMALIES (RARE) PIRIFORM SINUS—–CAN BE CONFUSED WITH A LARYNGOCELE–ALSO GOES THROUGH THE T-H MEMBRANE—>90% OF ACUTE PEDIATRIC THYROIDITIS ASSOC WITH A LEFT PIRIFORM SINUS TRACT (3RD POUCH DEFECT) POST TO ICA AND ECA DEEP TO CN 9 SUPERFICIAL TO 12 FOURTH ARCH CARTILAGE BAR—-THYROID AND CUNEIFORM CARTILAGE MESODERM—CRICOTHYROID, CRICOPHARYNGEUS, INF PHARYNGEAL CONSTRICTORS NERVE—-SLN (X)—JUGULAR AND NODOSE GANGLION ARTERY—–AORTA(LEFT) AND PROXIMAL SUBCLAVIAN(RIGHT) THEORETIC 4TH APPARATUS ANOMALY WOLD GO FROM APEX OF PIRIFORM UNDER THE PATH OF THE RLN AND THEN ANT TO THE SCM—HAS NOT BEEN REPORTED YET 4TH POUCH—-SUP PTGS AND ULTIMOBRANCHIAL BODY—APUD CELLS OF NEURAL CREST ORIGIN (NOT IN BOT)—THE ETIOLOGY OF MEDULLARY THYROID CA FIFTH/SIXTH ARCH—ARTERY ANT TO NERVE(IF NOT=BAYFORD’S SYNDROME) CARTILAGE BAR—CRICOID, ARYTENOID, CORNICULATE MESODERM—-ALL INTRINSIC LARYNGEAL MUSCLES EXCEPT CRICOTHYROID NERVE—-RLN ARTERY—-PULMONARY ARTERY(LEFT) AND DUCTUS ARTERIOSUS, NEUROECTODERMAL—NEURAL CREST CELL TUMORS NOTOCHORD= STRUCTURAL VESTIGE FORMED FROM MESODERM (CLIVAL CHORDOMA) EVENTUALLY BECOMES THE NUCLEUS PALPOSUS—VERTEBLRAL COLUM FORMS AROUND IT STIMULATES NEURULATION PROCESS IN THE OVERLYING NEUROECTODERM NEURULATION—-SOME OF THE NEUROECTODERM SEPERATES AN MIGRATES OUT TO FORM PERIPHERAL NEURAL STRUCTURES: AFFERENT–DORSAL ROOT GANGLION AUTONOMIC GANGLION—-SYMPATHETIC TRUNK, CN 3, 7, 9, AND 10 (GLOMUS CELL TUMORS—PARAGANGLIOMAS) LINGUAL THYROID ECTOPIC THYROID—ANYWHERE FROM CIRCUMVALLATE PAPILLA TO EPIGLOTTIS MUST BE POST TO CIRCUMVALLATE PAPILLA AND TUBERCULUM IMPAR IS A FAILURE OF DESCENT (?ARRESTING MATERNAL ANTIBODIES) 4TH WEEK–FORAMEN CECUM LINGUALE DESCENDS DOWN PRIOR TO FORMATION OF THE BOT OR HYOID BONE
TGDC LINED WITH EPITHELIUM TOWARDS THE END OF DESCENT IT IS JOINED BY THE LATERAL FOURTH POUCH NEUROECTODERMAL C-CELLS (PARAFOLLICULAR CELLS) FROM THE ULTIMOBRANCHIAL BODY——CAN FORM MEDULLARY CA INCIDENCE = 1/100,000 FEMALE 4.7:1 33% CLINICALLY HYPOTHYROID 70-100% HAVE LINGUAL THYROID AS ONLY FUNCTIONING THYROID TISSUE VERY RARELY UNDERGO MALIGNANT DEGENERATION—-27 CASES (APPEARS TO HAVE THE SAME INCIDENCE AS THYROID IN THE NL LOCATION CAVEATE—-CANNOT HAVE MEDULLARY THYROID CA HERE AS THE NEURAL CREST DERIVED C-CELLS (PARAFOLLICULAR CELLS) MIGRATE IN FROM THE ULTIMOBRANCHIAL BODY OFTEN WILL PRESENT WITH A MASS EFFECT —- DYSPHAGIA, DYSPHONIA, DYSPNEA, EVEN STRIDOR—–RARELY MAY HEMORRAGE OFTEN PRESENT AT A TIME OF STRESS WHEN HIGH TSH LEVELS PROMOTE GLANDULAR HYPERPLASIA Dx: ALWAYS PALPATE FOR NL THYROID GLAND LAB: TSH, T3, T4, THYROGLOBULIN CT WITH NO CONTRAST—NL THRYROID NATURALLY HAS ACCUMULATED I- TN99 SCAN—-DIAGNOSTIC—-AVOIDS THE NEED FOR Bx Rx: SYNTHROID SUPPRESSION—-LOWERS TSH—DECREASES GLANDULAR HYPERPLASIA—-DECREASES SYMPTOMS IF THIS FAILS—REPEAT IMAGING STUDIES——SURGERY IF NOT A SURGICAL CANDIDATE CONSIDER I131 (RAI) THYROGLOSSAL DUCT CYST (TGDC) UP TO 7 % OF ALL COMERS A CAN HAVE SOME RESIDUAL NOTED POST MORTEM PRIMARY MIDLINE NECK MASS IN PEDIATRICS (>DERMOID), 3 X MORE COMMON THAN A BRANCHIAL CLEFT ABNL, MIDLINE CERVICAL DEFECT INCIDENCE OF CA = RARE—–ALWAYS PAPILLARY NORMALLY THE THYROGLOSSAL DUCT DISSAPPEARS AT 9 WEEKS PRIMARILY AT THE HYIOD BONE(HYOID BONE = 2ND ARCH CARTILAGE/REICHERTS—ALMOST ALWAYS INVOLVED) > INFRAHYOID(65%) > SUPRAHYOID(25%) > SUPRASTERNAL (8-9%) > BOT(1-2%) 1-5 CM MOVE WITH DEGLUTITION AND TONGUE PROTRUSION (RETAINED FIBROUS THYROGLOSSAL DUCT TRACT) 2/3 PRESENT BEFORE AGE 10 90% IN THE MIDLINE, IF NOT DIRECTLY IN MIDLINE L > R LINED WITH EITHER RESP OR SQUAMOUS EPITHELIUM WITH ISLANDS OF LYMPHOID AND THYROID TISSUE ALMOST ALWAYS HAVE A PATENT PROXIMAL THYROGLOSSAL DUCT (TO THE FORAMEN CECUM) Dx: US, CT, MRI—PROBABLY SHOULD GET PRE OP TN99 THYROID SCAN AS THIS MAY BE THE ONLY FUNCTIONING THYROID TISSUE—THIS MAY NOT ALTER YOUR TREATMENT AND MANY SOURCES SAY NOT TO BOTHER—–BUT IT WOULD AT LEAST CLUE YOU IN TO THE NEED FOR FUTURE REPLACEMENT Rx: OBSERVATION (RARELY ASSOC. WITH A NEOPLASM) IF Hx OF RT—-THEN SHOULD REMOVE—–+/- POST OP RAI EXCISION VIA CISTRUNK PROCEDURE—-EXT APPROACH—REMOVE MID HYOID—-<4-5 % RECURRENCE 5 CM HORIZONTAL INCISION OVER THE CYST RAISE SUP AND INF SUBPLATYSMAL FLAP—-GELPIES DIVIDE (INFRAHYOID) STRAPS BOVIE RIGHT DOWN ON THE HYOID—CAN TAKE ALL MUSCLES OFF THE CENTRAL HYOID BEWARE OF 12 LATERALLY DISSECT OUT CYST—USE MARTINS ON STRAPS BONE CUTTERS ON HYOID FOLLOW CYST UP TO BOT AND DOWN TO PYRAMIDAL LOBE CLOSE OVER A #10 JP MIDLINE CERVICAL DEFECT A FAILURE OF BRANCHIAL ARCHES TO FUSE IN THE MIDLINE RARE OFTEN MISTAKEN FOR A TGDC CLEFT LIP—JUNCTION BETWEEN VERMILLION AND SKIN = MUCOCUTANEOUS RIDGE OR WHITE LINE (VERMILLION BORDER) HAS SEVERAL SPECIFIC ANATOMIC CHARACTERISTICS—-CUPID’S BOW, PHILTRIL DEPRESSION, TUBERCLE SENSATION—UPPER LIP—V2, LOWER LIP V3 MOTOR—LABIAL BR OF MARGINAL MANDIBULAR(ORBICULARIS) BLOOD—LABIAL(CORONARY) BR OF THE FACIAL ARTERY LYPHATICS—UPPER LIP—-SUBMANDIBULAR LN-S, LOWER LIP—SUBMENTAL LN’S PALATE—ANT 3/4 = BONEY, POST 1/4 = SOFT PRIMARY PALATE = PREMAXILLA(BEARS 4 INCISORS) PRIMARY PALAT SEPARATED FROM THE SECONDARY PALAT VIA THE INCISIVE FORAMEN SECONDARY PALATE=PALATINE PROCESS OF THE MAXILLA AND HORIZONTAL PLATE OF THE PALATINE BONE (HOUSES THE GREATER AND LESSER PALATINE FORAMEN AND PTERYGOID PROCESS OF THE PALATINE BONE(TENSOR VELI PALATINI LOOPS AROUND THIS))
CLEFT LIP AND PALATE (MULTIFACTORIAL PREDILECTION)—SIMPLE MENDELIAN INHERITENCE, ENVIRONMENTAL TERATOGENS, VITAMIN/ELEMENT DEFEICIENCY(FOLATE), GENETIC MUTATIONS CLEFT LIP +/- CLEFT PALATE (1/1000)—1/700 CAUCASIONS —-PRIMARILY MALE 2:1 CLEFT PALATE ALONE (1/2,000) —PRIMARILIY FEMALE 2:1 CAUCASIONS > BLACKS ALSO HIGH IN ASIANS AND NATIVE AMERICANS LOW INCIDENCE IN BLACKS CLEFT LIP AND PALATE COMBINATION IS MOST COMMON ANOMALY UNILAT (L>R) > BILATERAL PROBLEM IS IN EMBRYONIC PERIOD (WEEK 1-8) FOLATE DEFIECEINCY HAS BEEN IMPLICATED IF YOU HAVE ONE AFFECTED CHILD OR PARENT YOUR RISK FOR THE NEXT APPROACHES 4-6 % IF YOU HAVE TWO AFFECTED CHILDREN—9-10% ONE AFFECTED PARENT AND ONE AFFECTED CHILD—16-17%!!! 1% OF CLEFT LIP +/- PALATE = SYNDROMIC RARE ENTITY TO BE AWARE OF IS VELOCARDIOFACIAL SYNDROME (CHROMOSOME #22) 8% OF CLEFT PALATE IS SYNDROMIC—-STICKLER (AD), TREACHER COLLINS (AD), PEIRRE ROBIN SEQUENCE CLEFT PALATE WILL GET IMPROVED ETT FUNCTION FOLLOWING REPAIR (DILATOR TUBAE FUNCTION) SUBMUCOUS CLEFT = MUSCULAL DIASTASIS—ZONA PELLUCIDA (BLUISH MIDLINE STREAK)—OFTEN ASSOC WITH ABNORMALITY OF THE POST HARD PALATE (PALATINE BONE)—-LEVATOR PALATINI INSERTS INTO THE PALATINE BONE SIMONART’S BAND=THIN REMNANT OF TISSUE IN THE FLOOR OF THE NASAL VESTIBULE PROBLEMS FEEDING —- CLEFT PALATE—MUST FEED IN A LATERAL SLOPING POSITION WITH A BULB SYRINGE—-FREQUENT BURPING CLEFT LIP ALONE DOES NOT POSE MUCH OF A PROBLEM ETD (80%)—-ETT STAYS MORE HORIZONTAL, TVP LACKS APPROPTIATE ORIGIN VPI—SPEECH AND DIETARY THERAPY AIRWAY—PEIRRE ROBIN SEQUENCE LACK ANT TONGUE SUPPORT DENTAL PROBLEMS—-LAT MAXILLARY INCISORS—SUPERNUMERARY, DYSTROPHIED OR MISSING TEETH COMMON PSYCH REPAIR: MULTIDISCIPLINARY TEAM REPAIR LIP AT 10 LBS, HB 10, 10TH POST NATAL WEEK REPAIR PALATE 20-24 MONTHS—ALWAYS BEFORE AGE 2 VPI—BEST Rx IS A PHARYNGEAL FLAP—–MOST IMPORTATN PRE OP ASSESSMENT IS TO NOTE LAT PHARYNGEAL WALL MOTION—–RHINOLELIA APERTA—-NASAL REFLUX VPD = VELOPHARYNGEAL DYSFUNCTION—-PRIMARILY SEEN IN CLEFT PATIENTS “N” “M” AND “NG” ARE REALLY THE ONLY NASAL PHENOMES—ALL OTHERS REQUIRE VP COMPETENCE WILL ALWAYS REQUIRE SPEECH THERAPY OTHER VPI OPTIONS: BULB OBTURATOR PALATAL LIFT PROSTHESIS PHARYNGEAL FLAP—USUALLY SUP BASED—-CAN CERTAINLY EXACERBATE OSA–-MUST HAVE GOOD LAT PHARYNGEAL WALL MOTION—IF YOU DO NOT MUST DO A — SPHINCTER PHARYNGOPLASTY––BORROW POST TONSILLAR PILLARS—SWING BACK AS AN INNERVATED MYOMUCOSAL FLAP POST PHARYNGEAL WALL AUGMENTATION TONSILLECTOMY MAY HELP VELUM MOBILITY—MUST PRESERVE POST PILLARS FOR FUTURE OPTION OF SPHINCTER REPAIR PIERRE ROBIN SEQUENCE (MICROGNATHIA—-GLOSSOPTOSIS—”U” SHAPED CLEFT PALATE (50%)) ?INTRAUTERINE INSULT–A DEFORMATION RATHER THAN A MALFORMATION? 1/40,000 MR (NOT IN TREACHER COLLINS) MIXED HL—HIGH ASSOC WITH ETD AND OME—-CHL ASSOC WITH MOBIUS SYNDROME ASSOC WITH SUBGLOTTIC STENOSIS 2/3 OPHTHALMIC ABNL—DETACHED RETINA OR GLAUCOMA—ANY CLEFT CONSIDER A OPTHO CONSULT AND AUDIO—R/O STICKLER SYNDROME (AUTO D)—-GET A GENETICS CONSULT ASPIRATION AND RESULTANT PNEUMONIA IS COMMON MAY NEED A TRACH OR MAY GET BY WITH A TONGUE LIP ADHESION REPAIR THE PALATE WHEN THE AIRWAY PROBLEM HAS FINALLY RESOLVED DUE TO MANDIBULAR GROWTH 

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