Developmental Disturbances of Oral Structures

Developmental Disturbances of Oral and Para Oral Structures

• Malformation: Defect due to a localized error in morphogenesis resulting in an abnormal shape or structure, with interference in function. Example: cleft palate.
• Deformation: An alteration in shape or structure of a previously normally formed part. Example: torticollis.
• Anomaly: Any deviation from normal. It is the same as malformation but there is no interference with function. Example: peg-shaped lateral.
• Anomalad: Malformation and subsequently derived structural changes. Example: Robin anomalad, where hypoplasia of the mandible results in cleft palate and respiratory difficulty.

Congenital Developmental Anomalies

• These defects are present at birth or before birth during the intrauterine life because of either heredity or environmental influences.
• Example: Cleft lip & palate.

Acquired Developmental Anomalies

• These defects develop during intrauterine life due to some pathological environment conditions.
• Can be prenatal, neonatal, or postnatal.
• Example: Down syndrome (Trisomy 21 syndrome).

Down Syndrome (Trisomy 21 Syndrome)

• Flat face.
• Large anterior fontanel.
• Open sutures.
• Small slanting eyes with epicanthal folds.
• Open mouth.
• Cardiac abnormalities.
• Macroglossia.
• High arched palate.

Cleft Tongue/Bifid Tongue

• Complete cleft tongue: occurs due to lack of merging of lateral lingual swellings.
• Partial cleft tongue: occurs due to incomplete merging and failure of groove obliteration by underlying mesenchymal proliferation.
• Partially cleft tongue is more common and is manifested as a deep groove in the midline of the dorsal surface.
• Food debris and microorganisms collect in the base of the cleft and cause irritation.

Fissured Tongue/Scrotal Tongue

• Deep fissures may be seen in children or adults but increase with age.
• Down syndrome and Melkersson-Rosenthal Syndrome.
• Histologic features:
  • Atrophic stratified squamous epithelium.
  • Occasionally pseudoepitheliomatous hyperplasia.
  • Loss of papillae, elongated rete ridges, and lymphocytic infiltration.

Median Rhomboid Glossitis

• Central papillary atrophy of the tongue or posterior lingual papillary atrophy.
• It is an asymptomatic elongated erythematous patch of atrophic mucosa on the mid-dorsal surface of the tongue.
• A biopsy is rarely performed on a fissured tongue because of its characteristic diagnostic clinical appearance.
• Histologic examination has shown an increase in the thickness of the lamina propria, loss of filiform papillae of the surface mucosa, hyperplasia of the rete pegs, neutrophilic micro abscesses within the epithelium, and a mixed inflammatory infiltrate in the lamina propria.

Hairy Tongue

• Characterized by marked accumulation of keratin on filiform papillae of the dorsal surface resulting in a hair-like appearance.
• Histologic Features:
  • Presence of fungal hyphae.
  • Consist of elongated filiform papillae, with mild hyperkeratosis and occasional inflammatory cells.
  • Debris accumulation among the papillae and candidal pseudohyphae is not unusual finding.
  • A mild to moderately intense chronic inflammatory cell infiltrate may be seen within subepithelial and deeper fibrovascular tissues.

Black Hairy Tongue, Lingua Nigra, Lingua Villosa

• Elongated filiform papillae, with mild hyperkeratosis and occasional inflammatory cells.
• Debris accumulation among the papillae and candidal pseudohyphae is not unusual finding.

Enamel Hypoplasia

• Teeth exhibit complete absence of enamel or there may be presence of enamel on some focal areas.
• Hypoplastic type: Lack of differentiation of ameloblast cells with little or no matrix formation.
• Hypocalcification type: Abnormal matrix structure & mineral deposition.
• Hypomaturation type: Alteration in the enamel rod & rod sheath structures.

Dentinogenesis Imperfecta

• It is the hereditary developmental disturbance of the dentin in the absence of any systemic disorder.
• Affected teeth are gray to yellowish-brown.
• Histologic Features: Enamel & mantle dentin are normal. The dentin, on the other hand, is composed of irregular tubules, with large areas of uncalcified matrix. Also known as “Hereditary opalescent dentin” & “Capdepont’s teeth”.
• Remaining dentin is severely dysplastic & exhibits vast areas of interglobular dentin.
• Dentinal tubules are short, disoriented, irregular & widely spaced.
• Classification:
  • Dentinogenesis imperfecta I: It occurs with Osteogenesis Imperfecta with opalescent teeth. Deciduous teeth more severely affected. Large pulp chamber with pulp stones.
  • Dentinogenesis imperfecta II: It is an autosomal dominant condition without associated bone disorder. Both deciduous and permanent teeth are equally affected.
  • Dentinogenesis imperfecta III: It is a rare autosomal recessive condition where the dentin is abnormal and radiolucent. It does not occur with Osteogenesis Imperfecta or any other systemic disorder.

Etiology of Micrognathia

• Congenital:
  • Pierre Robin syndrome.
  • Catel Manzke syndrome.
  • Cerebrocostomandibular syndrome.
• Intrauterine acquired conditions:
  • Congenital syphilis.
  • Turner syndrome.
• Chromosomal abnormality:
  • Trisomy 18.
• Autosomal dominant conditions:
  • Treacher Collins syndrome.
  • Pallister Hall Syndrome.

Facial Hemiatrophy

• Also known as Parry Romberg Syndrome, Progressive Facial Hemiatrophy, Progressive hemifacial atrophy.
• Parry and Romberg in 1846.

Oral Manifestations of Facial Hemiatrophy

• Dental anomalies: incomplete root formation, delayed eruption, and severe facial asymmetry.
• Eruption of teeth on the affected side may be retarded.
• Atrophy of half of the upper lip and tongue.
• Deviation of jaws while opening the mouth.
• A characteristic loss in the soft tissues of essentially half the face.

Explore the various types of developmental disturbances affecting oral and para oral structures. From malformations to acquired anomalies, learn how these conditions arise and impact function. This quiz will test your knowledge of congenital and acquired developmental anomalies and their implications.