214 Reviews awl abstracts

the first operation, the type of surgical intervention, an(l t hc numlwr of op~‘r;~. tions performed. In addition, it has been found that cl~~t’t palate, (~llildr~v~ m: significantly retarded in communication skills.

Spriestcrbach of t#he TJniversity of Iowa surveys present knowledge on the effects of clefts on speech and points out areas that require further rt>search. It is known that velopharyngeal incompetence is principally responsible for articulation errors and nasa1it.y. There is no method of predicting the type of speech defect that will bc evidenced by a cleft palate person. Much will depend on the speaker’s ability to compensate. Among compensating factors arc in- creased contraction of Passavant’s pad, tongue-palate valving! lingual elevation of t,he palate, lingual occlusion of open clefts, and constriction of the nares.

The following statement from an article by Johnson, Darley, and Spriester- bath is significant to orthodontists and those who are only too ready to blame speech defects on dental malocclusion : “No big point is to be made of a space between the upper incisors, for example, when the speaker’s only misarticulation is a w for T substitution.” One must first establish a. diagnostic relat,ionship.

.r. :I. R.

Dental Anomalies in Harelip and Cleft Palate

By Arne Bb’hn. Acta odont. smndina.v. 21: Supp. 0~70, 38, 1963.

The findings of the entire study, according to Biihn, indicate the following: 1. The retrogression of the number of teeth from the deciduous to the

permanent dentition is mainly dependent on prenatal factors. 2. Both fissural teeth represent the lateral incisor, and a normal lateral in-

cisor may consist not only of both a premaxillary and a maxillary component but also possibly of only one of them if the other is missing. Under certain con- ditions, the component,s show different form-giving capacity. Their growth po- tential is easily influenced, positively or negatively, by developmental disturb- ances in the primary palate region. As a result of such di&urbances, the com- ponents may develop separately and a number of typical and atypical dental types are formed.

3. The development of supernumerary central or lateral incisors or canines may be due to disturbance of the anlage of the lateral incisor in patients without clefts as well as in those with smaller or larger clefts.

4. Increasing size of the cleft, from an isolated cleft lip to a bilateral com- bined cleft, is, with certain exceptions, accompanied by decreasing size of the teeth in the front region of the ma,xilla and also by a generallp increasing ten- dency toward hypodontia, in the permanent dentition. The exceptions are inter- preted as indications of reactive growth impulses to the cleft formation.

5. No dividing line has been demonstrated between the so-called microforms of cleft and similar anomalies of another possible origin.