Chapter 27. Diseases of the dentofacial system and oral cavity organs

Malformations of the orofacial region

Malformations of the orofacial region (maxillofacial dysmorphia) are not uncommon. According to etiology, they may be hereditary, multifactorial and intrauterine.

According to clinical and morphological manifestations, these malformations are divided into developmental abnormalities of the face, jaws and lips, teeth, their enamel and dentin, tongue, salivary glands.

Malformations of the orofacial area can be isolated, combined with other develop­mental abnormalities of this region, or be a component of hereditary syndromes (Down, Patau, Edwards, etc.) with multiple malformations.

The group of malformations of the face, jaws and lips includes facial clefts, prognathism (projecting lower jaw or chin); hypognathism (underdeveloped lower jaw); exostoses (outgrowths of bone tissue of the palate and jaw); congenital fistulas of the lower lip (paramedian impressions in the lip, in which ducts of small salivary glands open); Fordyce granules (Fordyce disease, Fox-Fordyce disease, seborrheic cysts).

Facial clefts (dysraphim) are found at a rate of 1 per 250-2,500 newborns, more often unilateral, in some cases they are concealed: subcutaneous or submucosal.

Lateral cleft of the upper lip in the projection of the upper lateral incisor tooth (hare lip, cheiloschisis) and cleft palate (palatoschisis) account for up to 45% of all orofacial malformations, and in half of cases, they are combined - cheilopalatoschisis (fig. 27.1), and in 15% are associated with other defects. Often, a retained or absent maxillary lateral incisor is noted. The combination of palatoschisis with small size of the lower jaw bone (lower micrognathia) and tongue (microglossia) with tongue retraction (glossoptosis) and impaired breathing is called Pierre Robin s­yndrome.

When the palatal cleft is cross-cutting, newborns have breathing, sucking and swallowing disorders, which leads to ingress of food masses from the mouth into the nasopharynx and their aspiration with the development of aspiration pneumonia. With age, speech disorders develop in such children.

Fordyce granules (Fordyce disease, Fox-Fordyce disease, seborrheic cysts) are clusters of enlarged sebaceous glands without excretory ducts or with impaired patency in the form of nodules 1-2 mm in size and yellowish in color on the lips and mucous membrane of the cheeks, esophagus, as well as in the area of genital organs, breast nipples. 35% of patients with Fordyce granules are women and 60% are men. Such formations are regarded as a variant of the norm; however, they cause cosmetic defects, and can also be mistaken for tumors or skin diseases.

Fig. 27.1. Lateral left-sided cleft of the upper lip, alveolar process, and hard palate (cheilopalatoschisis)

An example of intrauterine malformation is alcohol syndrome (alcoholic embryofetopathy) in children born by women who systematically consumed alcohol during pregnancy: hypognathism, in 7% - high hard palate, cleft upper lip and palate (cheilopalatoschisis), malformations of the nervous, cardiovascular, genitourinary systems, extremities.

Malformations of teeth, their enamel and dentin are extremely diverse. These include the following disorders: number of teeth (edentia, hypodontia or oligodontia, hyperodontia, dichotomy of teeth); teeth location (retained and impacted teeth); size and shape of teeth (macrodontia, microdontia, reduction or increase in the quantity of cusps, roots, their length, forms, fusion of teeth, etc.); eruption can be premature (natal teeth that are present at birth), or delayed, for instance, in congenital hypothyroidism, gingival fibromatosis, etc.; premature teeth loss.

Abnormalities of enamel and dentin development are represented by endogenous and exogenous pigmentation, imperfect amelogenesis, enamel hypoplasia and imperfect dentinogenesis (see section “Non-carious lesions of dental tissue”).

Tongue malformations include: aglossia (congenital lack of tongue); micro- or hypoglossia (tongue underdevelopment); macroglossia (tongue enlargement), cleft tongue; ankyloglossia (deformaty or misplaced attachment of the tongue frenulum); lingual goiter (thyroid heterotopy).

Malformations of salivary glands are represented by aplasia and hypoplasia; atresia and doubling of the ducts of large salivary glands; ectopy of salivary glands (in the lymph nodes and soft tissues of the head and neck, jaw bones, tonsils); adenomatoid hyperplasia, polycystic parotid glands, as well as xerostomy (“dry syndrome”), which contributes to the development of caries and periodontitis.