Cleft lip (harelip)

Facial clefts may occur along any plane on the face where embryonic processes normally join and fuse. Thus we may recognize such anomalies as the oblique and transverse facial clefts, which extend from the upper lip or ala of the nose to the eye and from the angle of the mouth to the ear, respectively. The most important of the facial clefts, however, is the cleft lip, mandibular or maxillary.

The mandibular cleft lip is an extremity rare condition which occurs in the midline of the lower lip and arises owning to failure of union of the mandibular processes at this site. Only the lip may be involved or, occasionally, both the lip and the jaw.

The maxillary cleft lip is the more common and more important of the lip clefts. It has been suggested that this cleft is due not to an actual lack of union оf processes, but rather to a failure of the connective tissue to penetrate the united epithelium with the result that a continuous structure is not formed. Since the line of union and fusion normally occurs on either side of the midline, with a single median structure present that is derived from the median nasal process, it is obvious that the maxillary cleft may be a unilateral or a bilateral defect, but not a midline one. Occasionally, however, a portion of the median nasal process is completely absent, and the resulting cleft does appear in the midline.

Etiology. The etiology of the cleft lip is undoubtly a varied one with many interesting ramifications. Heredity is one of the important factors to be considered. Numerous clinical studies have shown that the incidence of cleft lip in children born to similarly affected parents may be as high as 45 per cent. Nutritional disturbances are also of importance.

Clinical features. The maxillary cleft lip may present a varied clinical picture depending upon the severity of the condition. A classification of such clefts according to appearance is as follows:

1) unilateral incomplete (33%);

2) unilateral complete (48%);

3)bilateral incomplete (7%);

4) bilateral complete (12%).

As the names would indicate, the unilateral cleft lip involves only one side of the lip, the bilateral, both sides of the lip. The latter type has given rise to the term "harelip", which is now frequently applied to all cleft lips. The incomplete cleft extends for a varying distance toward the nostril and frequently involves the palate as well. The complete cleft extends into the nostril and even more commonly involves the palate also.

The cleft lip and cleft palate are somewhat more common in boys than in girls, and the lip cleft occurs three times more frequently on the left side than on the right.

Treatment. Most cases of cleft lip may be surgically repaired with excellent cosmetic and functional results. It is customary to operate before the patient is one month of age or at a time when he has regained his original birth weight and is still gaining.

Odontogenic cysts

The odontogenic cysts are derived from epithelium associated with the development of the dental apparatus. Since several types of these cysts may occur, dependent chiefly upon the stage of odontogenesis during which they originate, various investigators have attempted to give a classification and system of nomenclature of the lesions. One of the simplest and yet most practical is a classification of Robinson and Koch:

l) primordial cyst;

2) dentigerous cyst;

3) periodontal cyst: a) apical, b) lateral; 4) gingival cyst.

A cyst is defined as a pathologic epithelium-lined cavity usually containing fluid or semisolid material. All odontogenic cysts satisfy these criteria, and, in addition, are nearly always completely enclosed within bone. The epithelium associated with each of the odontogenic cysts is derived from one of the following sources: l) a tooth germ; 2) the reduced enamel epithelium of a tooth crown; 3) the epithelial rests of Malascez, remnants of the sheath of Hertwig, or 4) remnants of the dental lamina.

The diagnosis of any of the odontogenic cysts and their correct identification as to type depend upon microscopic examination of the tissue coupled with close study of the clinical and roentgenographic findings.

The apical periodontal cyst is the most common of the odontogenic cysts. It involves the apex of an erupted tooth and is most frequently a result of infection via the pulp chamber and root canal through carious involvement of the tooth.

The gingival cyst is a cyst of gingival soft tissue, occurring in either the free or attached gingiva.

The gingival cyst appears to occur at any age and presents generally as a small, well circumscribed painless swelling of the gingiva, sometimes closely resembling a superficial mucocele. The lesion is of the same color as the adjacent normal mucosa and seldom measures over 1 cm in diameter, generally much less. Histologically, the gingival cyst is a true cyst, since it is an epithelium-lined cavity which usually contains fluid. The lining epithelium is generally very thin, flattened squamous epithelium. The lesion lies free in the connective tissue of the gingiva and may or may not be associated with inflammatory cell infiltration.

Treatment. Local surgical excision of the lesion in adults is usually recommended, and the lesions do not tend to recur. A neoplastic potential has never been reported.

For cysts occurring in infants, generally no treatment is recommended, since these represent the usual progression in the fate of degenerating dental lamina and will ultimately disappear.