Muhad Noorman P , team dentowesome, final year.

Cleft palate and Cleft lip comprises the complex of Orofacial clefts . Both comprises congenital malformations affecting oro-facial region.
Failure of fusion of nasal and maxillary process leads to cleft of primary palate which can lead to unilateral and bilateral. Cleft of secondary palate is medial, Varies from bifid uvula to complete cleft palate up to incisive foramen.

Etiology:-
Clinically, Isolated Cleft palate
and Cleft lip with or without Cleft palate has been established.

Factors playing  role in Development of Orofacial cleft comprises

1)Heredity (40%of cleft lip and 20% cleft lip appear genetically- single gene/polygenic mutation, Monozygotic twins far likely to get)
2)Nutritional disturbances (experimentally proved in rat fed on abnormal dietary regimen caused cleft palate) mostlty- Riboflavin,Folic Acid Deficiency.

3) Physiologic, Emotional stress, Traumatic also thought to cause
4) Circulating Alcohol ,Drugs ,toxins.
5)Environmental Factors– Teratogens (phenytoin, methotrexate, Corticosteroid, Sodium Valproate)
6)Syndromic Clefting
Treacher collins syndrome
Pierre Robin Syndrome
Stickler syndrome
Oro Facial Digital syndrome
Trisomy of 13,18
Van Der Voude syndrome ( lip pit syndrome, autosomal dominant , deletion of 1q32 , clinically presenting with cleft lip and palate and medial pits on lower lips on vermillion border.Also include ankyloglossia,high arch palate ,maxillary hypodontia and sygnathia)

EMBRYOGENESIS AND CLEFTING

During sixth and seventh weeks of development upper lips forms when median nasal process merges each each other and  fuses with maxillary process of 1st branchial arches. Mid portion of upper  lip is derived from median nasal process, lateral derived from maxillary process. Lateral nasal process involved in ala of nose. Primary palate is formed from merging of median nasal process to form intermaxillary segment, which give rises to premaxilla
(bone including 4 incisor teeth). Secondary palate make up 90% of palate formed from maxillary process of first branchial arches.Defective fusion of median nasal process with maxillary process forms cleft lip. Failure of palatal shelves to fuse result in cleft palate
45% are Cleft lip with palate
30% Cleft palate alone
25% with isolated cleft lip

 

Reference:- Textbook of maxillofacial surgery- Balaji. Textbook of embryology- Inderbir Singh. Neville Oral pathology. Images credits : Image 1 – Internet medscape (https://emedicine.medscape.com/article/950823-overview

Image 2 :- Internet, Children Hospital of Philadelphia , ( https://www.chop.edu/conditions-diseases/van-der-woude-syndrome)