DH 156 - Chapter 5 - Development of Orofacial Features.ppt

Chapter 5: Development of Orofacial Structures 1 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Chapter Outline Orofacial development Pa...

Chapter 5: Development of Orofacial Structures 1 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Chapter Outline Orofacial development Palatal development  Primary palate formation  Secondary palate formation  Completion of palate Nasal cavity and septum development Tongue development  Body of tongue formation  Base of tongue formation  Completion of tongue formation 2 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Orofacial Development 4th – 12th week Later embryonic to early fetal period 3 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Case Study 5.0 Age 9 YRS Scenario Sex Male A patient of 4’ 6” record has a Height mother that is Weight 78 LBS concerned about 90/60 his speech. He BP reports that his Chief “My mom is tongue feels like Complaint concerned it is hard to use. about my In the past, the speech and I lingual frenum feel like my has been noted tongue is hard to have a short to use.” attachment that Medical Allergy to extends to the History penicillin tongue apex. It was checked Current None annually and Medications discussed with Social Grade school his mother. History student that likes to sing A clinical photograph was Fehrenbach, MJ, Weiner J. Saunders Review of Dental Hygiene, ed 2. Saunders, Philadelphia, 2009 taken in the past. 4 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Development of Orofacial Structures PALATAL DEVELOPMENT 5 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Palatal Development: Time Table The formation of the palate starts during the fifth week of prenatal development, within the embryonic period. The palate at this time is formed from two separate embryonic structures:  primary palate and secondary palate. The palate is then completed later during the twelfth week  within the fetal period. 6 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Palatal Development: Time Table Fifth to sixth week Primary palate: Intermaxillary segment from fused medial nasal processes Sixth to twelfth week Secondary palate: Fused palatal shelves from maxillary processes Twelfth week Final palate: Fusion of all three processes 7 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Palatal Development: Process Overview Final palate involves the fusion of swellings or tissue from different surfaces of the embryo to meet and join similar to that of the fusion of the neural tube. Figure 5-1 8 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Primary Palate Formation During the fifth week of prenatal development  Still in embryonic period  Intermaxillary segment forms  From fulsed medial nasal processes 9 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Development of Intermaxillary Segment Figure 4-7 The development of the intermaxillary segment from the fused medial nasal processes on the inside of the stomodeum. 10 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Primary Palate Formation The intermaxillary segment also gives rise to the primary palate (or primitive palate). At this time, the primary palate serves only as a partial separation between the developing oral cavity proper and nasal cavity. 11 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Secondary Palate Formation 6th week Embryonic period Bilateral maxillary processes give rise to two palatal shelves (or lateral palatine processes). Figure 5-4 12 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Secondary Palate Formation Nanci A. Ten Cate’s Oral Histology, ed 7. Mosby, St. Louis, 2008 13 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Secondary Palate Formation These shelves grow inferiorly Along both sides of the developing tongue. Figure 5-4 14 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Secondary Palate Formation The tongue is also forming on the floor of the pharynx As the developing tongue muscles begin to function, the tongue contracts and moves out of the way of these developing palatal shelves. Figure 5-4 15 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Secondary Palate Formation Thus the shelves move into a horizontal position, now superior to the developing tongue. Next, the two palatal shelves elongate and move medially toward each other. Fuse to form the secondary palate. Figure 5-4 16 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Figure 5-5 17 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Secondary Palate Formation Gives rise to the posterior two thirds of the hard palate Anterior maxillary canines and posterior teeth Figure 5-6 18 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Secondary Palate Formation Median palatine raphe Median palatine suture  Indicates the line of fusion of the palatal shelves. Figure 5-6 19 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Epstein Pearl The small white papule seen in the midline of the palate of this infant is an Epstein pearl. It represents epithelial tissue that becomes trapped during the palatal fusion. Nanci A. Ten Cate’s Oral Histology, ed 7. Mosby, St. Louis, 2008 20 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Completion of Palate Posterior part of the primary palate meets the secondary palate Figure 5-4 21 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Figure 5-5 22 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Completion of Palate Nanci A. Ten Cate’s Oral Histology, ed 7. Mosby, St. Louis, 2008 23 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Palatal Development Review: Fifth to sixth week Primary palate: Intermaxillary segment from fused medial nasal processes Sixth to twelfth week Secondary palate: Fused palatal shelves from maxillary processes Twelfth week Final palate: Fusion of all three processes 24 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Developmental Disturbances Palate and Associated Tissue Standring S: Gray's Anatomy, ed 40, Edinburgh, 2009, Churchill Livingstone 25 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Cleft Palate Failure of fusion of the palatal shelves  with the primary palate  And/or with each other Figure 5-7 26 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Cleft Palate with Cleft Lip Fehrenbach, MJ, Weiner J. Saunders Review of Dental Hygiene, ed 2. Saunders, Philadelphia, 2009 27 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Bilateral Cleft Lip With Cleft Palate Bilateral cleft lip and palate in a 2-month-old boy. Sagittal T1 MRI. Elsevier, Imaging Consult, imaging.consult.com, 2009 28 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Unilateral Cleft Lip With Cleft Palate Coronal ultrasound of the fetal face at 21 weeks gestation shows a unilateral cleft lip and palate, indicated by positions of the lower lip (solid arrow), tip of the nose (asterisk); and two sides of the upper lip (open arrows). Notice the large defect in the lip. Elsevier, Imaging Consult, imaging.consult.com, 2009 29 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Cleft Uvula Cleft uvula (or bifid uvula) is the least complicated example of cleft palate Failure of fusion between nasal and maxillary processes. Fehrenbach, MJ, Weiner J. Saunders Review of Dental Hygiene, ed 2. Saunders, Philadelphia, 2009 30 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Development of Orofacial Structures Nasal Cavity and Septum Development 31 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Nasal Cavity and Septum Development The nasal cavity forms in the same time frame as the palate, from the fifth to twelfth week of prenatal development. It will serve as part of the respiratory system. 32 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Nasal Cavity and Septum Development The future nasal septum of the nasal cavity is also developing when the palate is forming. The structure of the nasal septum, similar to the primary palate, is a Figure 5-9 growth from the fused medial nasal processes. 33 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Nasal Cavity and Septum Development The tissues that form the nasal septum will grow inferiorly and deep to the medial nasal processes and superior to the stomodeum. 34 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Nasal Cavity and Septum Development The vertical nasal septum then fuses with the horizontally oriented final palate after it has formed. Figure 5-5 35 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Deviated Septum A deviated septum occurs when the thin wall that makes up the nasal septum inside the nose is displaced to one side. The nasal septum separates the right and left nasal cavities and ideally is situated in the center of the nose, equally separating the two sides. 36 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Deviated Septum Elsevier, Imaging Consult, imaging.consult.com, 2009 37 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Development of Orofacial Structures Tongue Development 38 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Tongue Development The tongue develops during the fourth to eighth week of prenatal development. It develops from independent swellings located internally on the floor of the primitive pharynx, formed by the first four branchial arches. 39 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Development of Tongue: Time Table 5-2 Time Period With Tongue Parts Involved  Fourth to eighth week  Body: Tuberculum impar and lateral lingual swellings appear  Base: Copula overgrowing second branchial arches  Eighth week  Completed Tongue: Merging of anterior swellings of body and copula of base 40 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Body of Tongue Development During the fourth week of prenatal development, Within the embryonic period The tongue development begins as a triangular median swelling, the tuberculum impar Figure 5-11 41 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Tongue Development The single tuberculum impar (b) is located in the midline, on the floor of the primitive pharynx 42 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Body of Tongue Development Later, two oval lateral lingual swellings develop on each side of the tuberculum impar. The paired lateral lingual swellings grow in size and merge with each other. Figure 5-11 43 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Body of Tongue Development Then the two fused swellings overgrow and encompass the disappearing tuberculum impar form the anterior two thirds, or body of the tongue Figure 5-11 44 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Body of Tongue Development The median lingual sulcus is a superficial demarcation of the line of fusion of the two lateral lingual swellings Figure 5-11 45 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Base of Tongue Formation Immediately posterior to these fused anterior swellings, a pair of swellings, the copula, becomes evident. Figure 5-11 46 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Base of Tongue Formation The copula gradually overgrows the second branchial arch, or hyoid arch, to form the base of the tongue, or posterior one-third. Figure 5-11 47 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Base of Tongue Formation Even farther posterior to the copula is the projection of a third median swelling, the epiglottic swelling. Derived from mesenchyme Future epiglottis Figure 5-11 48 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Completion of Tongue Formation 1. Copula of the tongue base 2. Overgrowing the second branchial arch, 3. merges with the anterior swellings of the first branchial arch  Occurs during the eighth week of prenatal development. Figure 5-11 49 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Completion of Tongue Formation This fusion is superficially demarcated by the sulcus terminalis Foramen cecum  Beginning of thyroglossal duct  Is the pathway for thyroid gland’s migration into neck region Figure 5-11 50 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Completion of Tongue Formation Nanci A. Ten Cate’s Oral Histology, ed 7. Mosby, St. Louis, 2008 51 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Development of Tongue: Time Table 5-2 Time Period With Tongue Parts Involved  Fourth to eighth week  Body: Tuberculum impar and lateral lingual swellings appear  Base: Copula overgrowing second branchial arches  Eighth week  Completed Tongue: Merging of anterior swellings of body and copula of base 52 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Developmental Disturbances Tongue Standring S: Gray's Anatomy, ed 40, Edinburgh, 2009, Churchill Livingstone 53 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. Developmental Disturbances Tongue Ankyloglossia is described as “tongue‑tied,” which results from a short attachment of the lingual frenum that extends to the tongue apex. Figure 5-12 54 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.  Case Study 5.0 Age 9 YRS Scenario Sex Male A patient of 4’ 6” record has a Height mother that is Weight 78 LBS concerned about 90/60 his speech. He BP reports that his Chief “My mom is tongue feels like Complaint concerned it is hard to use. about my In the past, the speech and I lingual frenum feel like my has been noted tongue is hard to have a short to use.” attachment that Medical Allergy to extends to the History penicillin tongue apex. It was checked Current None annually and Medications discussed with Social Grade school his mother. History student that likes to sing A clinical Fehrenbach, MJ, Weiner J. Saunders Review of Dental photograph was Hygiene, ed 2. Saunders, Philadelphia, 2009 taken in the past. 55 Copyright © 2011, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.