Developmental defects of the oral and maxillofacial regions

1. Developmental defects of the oral and maxillofacial regions Ajiravudh Subarnbhesaj

2. Developmental defects of the jaws Orofacial clefts Coronoid hyperplasia Condylar hyperplasia Condylar hypoplasia Bifid condyle Exostoses Torus palatinus Torus mandibularis Eagle syndrome Stafne defect Hemihyperplasia Progressive hemifacial atrophy Segmental odontomaxillary dysplasia Crouzon syndrome Apert syndrome Mandibulofacial dysostosis Pierre Robin syndrome

3. Orofacial clefts Most common major congenital defects in humans Frequency of CL +/- CP : Native americans,Asians, Whites, Blacks CL+CP 45%, CPO 30%, CLO 25% More common in males than in females CL: 80%-unilateral (70%-left side), 20%-bilateral 70% of unilateral CLs are associated with CP Minimal manifestation of CP is a bifid uvula Submucosal palatal-the surface mucosa is intact, but a defect exists in the underlying musculature of the soft palate

5. Coronoid hyperplasia Rare, unknown cause Male-to-female ratio = 5:1 Endocrine influence, heredity Bilateral CH is more common than unilateral CH* Restricts mandibular opening and causes deviation toward affected side*

7. Condylar hyperplasia Excessive growth of one of the condyles Endocrine disturbances and trauma Facial asymmetry, prognathism, crossbite and open bite Most commonly found in adolescents and young adults Self limiting condition

10. Condylar hypoplasia Underdevelopment of the mandibular condyle Congenital (mandibulofacial dysostosis, hemifacial microstomia) Acquired (trauma to the condylar region during infancy or childhood, infection, radiation therapy, RA, OA)

12. Bifid condyle Double-headed mandibular condyle Medial and lateral head divided by an anteroposterior groove Trauma, abnormal muscle attachment, teratogenic agents, persistence of a fibrous septum within the condylar cartilage Popping or clicking sound when opening the mouth

14. Exostoses Localized bony protuberances that arise from the cortical plate Adults A bilateral row of bony hard nodules along the facial aspect of the maxillary and mandibular alveolar ridge

16. Torus palatinus/mandibularis Torus palatinus Common exostosis that occurs in the midline of the vault of the hard palate Genetics vs environmental or both Asian and Inuit Female:Male = 2:1 Torus mandibularis A bony protuberance along the lingual aspect of the mandible above the mylohyoid line in the region of the premolars Bilateral May appear on periapical radiographs as a radiopacity superimposed on the roots of the tooth

18. Eagle syndrome Elongation of the styloid process or mineralization of the stylohyoid ligament complex Adults, Most commonly unilateral Vague, radiated facial pain while swallowing, turning the head or opening the mouth Classic Eagle syndrome � After tonsillectomy Stylohyoid syndrome � impinge on the internal or external carotid arteries and associated sympathetic nerve fibers

20. Stafne defect An asymptomatic radiolucency below the mandibular canal in the posterior mandible, between the molar teeth and the angle of the mandible Typically well-circumscribed with a sclerotic border Mostly unilateral Reported in middle-aged and older adults, children is rarely affected Normal submandibular gland tissue No treatment required

22. Hemihyperplasia Asymmetric overgrowth of one or more body parts (right side) 2:1 female-to-male predilection Asymmetry may be noted at birth The enlargement becomes more accentuated with age especially at puberty Skin on the affected side: thickened, increased pigmentation, hypertrichosis, telangiectasias or nevus flemmeus Oral: Macroglossia, larger mandibular canal-crowns Differentiated from Proteus syndrome, NF1

24. Progressive hemifacial atrophy Atrophic changes affecting one side of the face ?trophic malfunction of the cervical sympathetic nervous system, trauma, hereditary Close relationship with localized scleroderma Starts during the first 2 decades of life Atrophy of the skin and subcut. Affecting the dermatome of CNV, osseous hypoplasia Oral: mouth deviated toward the affected side, unilateral atrophy of the tongue, unilateral posterior open bite, deficient root formation or resorption

26. Segmental odontomaxillary dysplasia Childhood Painless, unilateral enlargement of the maxillary bone along with fibrous hyperplasia of the overlying gingival soft tissues Missing developing maxillary premolars, hypoplastic primary teeth X-Ray: thickened trabeculae-relatively radiopaque, granular appearance

28. Crouzon syndrome Craniosynostosis : premature closing of the cranial sutures FGFR2 gene mutation on chromosome 10q26 Brachy-scapho-trigonocephaly Shallow orbit-visual impairment or total blindness Headaches, beaten metal skull Underdeveloped maxilla

30. Apert syndrome Characterized by craniosynostosis FGFR2 gene on chromosome 10q26 Autosomal dominant, paternal origin Tower(clover leaf) skull, ocular proptosis with hypertelorism, visual loss, hypoplastic middle face � mandibular prognathism, open- mouth appearance, syndactyly*, mental retardation, cleft soft palate

32. Mandibulofacial dysostosis Defects of structures derived from the first and second branchial arches Autosomal dominant TCOF1 gene mapped to chromosome 5q32-q33.1 Hypoplastic zygoma, narrow face, depressed cheeks, coloboma, tongue-shaped sideburns, anomalies of ears, underdeveloped mandible

34. Pierre Robin syndrome Triad: CP, mandibular micrognathia and glossoptosis The retruded mandible results in: Posterior displacement of the tongue Lack of support of the tongue musculature Airway obstruction * Respiratory difficulty in supine position noted from birth * The palatal cleft is often U0shaped and wider than isolated CP