Thumbsucking, Fingersucking and Malocclusion

Chandler (1878) was among the first dentists to assert that a relationship existed between thumb- and fingersucking habits and specific facial deformities. He felt that aside from the obvious displacement of teeth, the bones of the nares were frequently elongated and narrowed, and resulted in respiratory problems. Since that time, the chronic effects of these habits have been the subject of much debate but little systematic scientific attention.

Lewis (1930) studied 30 subjects and concluded that a typical pattern of malocclusion and deformity occurred in the deciduous teeth of patients sucking their thumbs, but that there was a general tendency for the malocclusions to correct themselves if the habit was broken by the time the child was five years old.

Rakosi (1958) studied 693 Czechoslovakian preschool children from three to six years of age in an effort to determine the effect of continued thumbsucking on the developing dentition. He noted that although 85% of the chilren with malocclusions had continued thumbsucking for more than four years, the 4-year period of the duration of thumbsucking did not appear to be the extremely critical etiologic factor for malocclusion. However, neither could it be ruled out.

Ruttle and his colleagues (1953) investigated the orthodontic casts of 36 children who had long periods of definite and persistent oral habits. The serial casts available ranged from 13 months to 149 months. Observations were also made on casts for 42 nonhabit cases and records were available ranging from 18 months to 167 months. They concluded that in thumb- and fingersuckers, elongation of the anterior segment of the maxillary arch occurs. Maxillary arch width appeared unaffected. They observed no statistically significant modification of the mandibular arch width in the deciduous first molar and the permanent first molar areas. The effect of thumb and finger habits on molar occlusion was not statistically or clinically significant.

Lamont (1978) has attempted to document the skeletal and dental effects from thumbsucking in arrested thumbsuckers (n=33). He concluded that neither the age at which thumbsucking was halted nor the type of appliance significantly altered overbite or overjet relationships. He also felt that normal vertical growth of the maxillary complex was impeded in children with persistent thumbsucking.

Popovich and Thompson (1973) studied 1,258 children and concluded that as the habit persisted, the probability increased that a child would develop a Class II malocclusion. In their sample, if the child stopped the habit before the age of six, the effects on the occlusion were frequently transient. In children in which the habit persisted beyond this period, no normal occlusions were observed at the age of twelve.

Thumb- and fingersucking habits appear to be relatively prevalent in infancy and childhood, and there appears to be some relationship between the habit and the development or exacerbation of malocclusions. In general, there is agreement that these habits are unlikely to result in permanent damage to the dentition, particularly if they are abandoned by the ages of four to five. If the individual persists beyond this period in thumb- or fingersucking, ic is felt that the likelihood of harmful effects is increased, although the extent to which they are increased is not fully known.

An additional variable requires consideration if the effect of thumbsucking on the occlusion is to be understood in its proper context. A number of writers have indicated that the heredity component of malocclusion seems to be more important for the development of later malocclusions than does persistent smoking self (e.g. Benjamin, 1962a,b; Sillman, 1951).

Personality Differences

An enormous amount of speculation has focused on presumed personality differences between children who engage in thumb- and fingersucking habits and those who do not. Both the psychological literature and the dental literature have assumed that there are differences. Freeden (1948) reported that there were no differences in the personalities of two groups which he studied. More detailed data suppol ng Troeden's conclusion comes from Davidson, Haryett, Sandilands, and Tensen (1967), who administered the California Test of Fors emily Relations who were persistent

Test and the Children's Aperception ret to onila. thumb- and fingersuckers. They concluded that there were no significant differences between children who engaged in the habit and those who did not as measured by their tests.

Sex Differences

No data exist to indicate a disp. sucking activities for either sex.

'onate amount of monnutritive

Methods of Controlling Habits

In this section, a number of app.oaches will be examined drawing upon the available experimental literature to sort the particular method of eliminating thumb- and fingers king habits.

The techniques available for eliminating these habits can be categorized into three groups: (1) prevention of the habit, (2) positive reinforcement, and (3) aversive conditioning methods.

Prevention of the habit. If one believes that thumb- and fingersucking habits should not be allowed to develop, some relatively simple techniques can be instituted shortly after birth to accomplish this goal. The inocuousness of the habit during the first four or five years of life does not seem to warrant such an approach; however, for the sake of completeness, the techniques which have been applied successfully will be discussed.

Chandler (1878) believed that thumbsucking in childhood should be prevented if possible. But for those children who persisted he recommended what might be the first behavioral approach by suggesting that the child sleep in a gown without openings for the arms as a method of eliminating the habit. Levin (1958) suggested a similar method of modifying the child's pajamas to prevent the child's putting his thumb or finger in the mouth.

Benjamin (1962) placed mittens on the hands of neonates during the first few months of life and observed that they engaged in sucking habits significantly less than a no-mittens control group, thus offering support to the notion that thumb- and fingersucking habits can be prevented from developing. Johnson (1938) had recommended boxing gloves as an excellent cure or preventive for thumbsucking. Sears and Wise's (1950) finding that early-weaned infants showed less sucking behaviors than late-weaned infants also suggests that carefully selected weaning schedules may prevent or reduce the occurrence of sucking behaviors. Although these methods are effective in preventing or reducing sucking activities, one may seriously question whether they should be implemented at such an early age particularly since the habit appears to drop out for most persons before the age of five or six.

The use of bitter-tasting substances applied to the thumb or finger have been recommended for some time as a method of prevention and treatment, but their use has been discouraged almost from the beginning (Chandler, 1978; Johnson, 1938).

Positive Reinforcement. Use of positive reinforcement or positive rewards to change behavior requires almost complete environmental control. Considerable effort on the part of the clinician is thus required. Baer (1952) has described a method of positive reinforcement which involves the withdrawal of positive rewards in the treatment of a 5-year-old boy. He employed the presentation of cartoons as a positive reinforcer. The boy was shown these cartoons which were removed when he placed his thumb in his mouth. When he removed his thumb, the cartoons were again presented. The more the child refrained from sucking his thumb, the more cartoons he was permitted to view.

Following Baer's report, a number of other case reports (Knight and McKenzie, 1974; Skiba, Pettigrew, and Alden, 1971; Martin, 1975) described apparent success with certain reinforcements such as attention, praise, or reading bedtime stories being contingent upon non-thumbsucking behavior.

Positive reinforcement is an effective treatment but requires more control over environmental contingencies than other techniques. For that reason, it probably is less likely to be used routinely than other methods to be described.

Aversive conditioning techniques. On the basis of the available evidence, the most effective techniques of eliminating sucking behaviors involve the aversive conditioning techniques, or the so-called punitive appliances. Although they have been used for many years (e.g. Massler and Wood, 1949; Massler and Chopra, 1950; Teuscher, 1940), these methods continue to be the subject of heated controversies. It appears quite clear that the source of the controversies stems from dentists' incomplete understanding of the theoretical positions mentioned earlier.

Although a number of writers have suggested that the elimination of sucking habits could be predicted and accomplished on the basis of learning theory, one of the first sound studies to systematically test the hypothesis was undertaken by Haryett and his colleagues (1967) and Davidson, et al. (1967). They divided 66 children, fours years of age and older, with chronic thumb- and fingersucking habits into six groups of eleven children each. The groups consisted of a (1) no-treatment control group; (2) psychologic treatment group (although the kind of treatment was not discussed); (3) palatal arch; (4) palatal arch and psychologic treatment (5) palatal crib; and (6) palatal crib and psychologic treatment.

All of the children were followed for ten months and evaluated regularly. At the end of ten months all the appliances were removed and additional evaluations were performed to ascertain if additional habits were developed; i.e., effects on speech, eating, etc. At the followup all 22 patients receiving the palatal crib treatment had stopped sucking habits whereas only 6 of the remaining 43 subjects stopped (one subject was lost from the study). Thus, they concluded that palatal cribs were effective in eliminating sucking habits whereas the other methods were not significantly different from the control group.

An effort was made to determine if any undesirable "mannerisms" developed as a result of the various treatments. Their findings showed no significant differences among the groups in the development of mannerisms. An analysis of associated habits at the time treatment was initiated revealed the interesting finding that in the palatal crib groups, there was also reduction in the number of associated habits--a finding completely opposite to what would be predicted by psychoanalytic theory. Of particular importance was the finding that over 82% of the children in the palatal crib groups stopped sucking habits within 7 days.

Haryett and his colleagues noted that transient speech problems developed in some children as did eating difficulties, although these were usually readily surmounted.

This study is the first to demonstrate that dental appliances (the palatal crib) effectively arrest sucking habits and do so without resulting in symptom substitutions or discernible damage to the child's psychological well-being.

Larsson (1972) investigated several methods for treating thumbsucking habits in children. Seventy-six 9-year-old children were divided into three treatment groups and one control group. The three treatment groups consisted of a positive reinforcement group for nonsucking, a negative group informed of the dangers of thumbsucking, and a palatal crib group. Treatment continued for two and one-half months. At one-year followup, all three treatment groups showed significantly more reductions in the habit than did the control group, although there were no differences among the experimental groups. interpretation of the effectiveness of the treatment groups is subject to question and may also suggest that any intervention may be effective.

The

For the sake of completeness, it must be noted that Lewis (1930) successfully treated four thumbsuckers, using a massed practice technique he ascribed to Dunlap. However, massed practice does not seem to have been used very frequently to eliminate sucking habits.

General Comment about Fixed Versus Removable Appliances

The most effective appliance is probably a fixed appliance which cannot be removed except by the dentist who places it. It is to be expected that the initial discomfort provided by the appliance until the patient relearns would result in the patient's removing it at the slightest discomfort, if it were removable.

The fixed appliance prevents this from occurring and also probably lessens the time required to eliminate the habit.

Bruxing and Grinding Habits in Children

Bruxing and grinding habits in adults appear to have received much more attention than in children. Most of the work available seems to have been carried out by Lindqvist (1974, 1973, 1972, 1971), and Lindqvist and Ringqvist (1973). Rieder (1976) reported that fully onethird of his sample of patients ranging in age from 10 to 79 years reported clenching and bruxing habits. However, only 4.6% of his sample of 153 patients were in the age range of 10 to 19 years, thus permitting no assessment to be made of the prevalence of bruxing and grinding habits in children. Reding, Rubright, and Zimmerman (1966) reported that in a subject sample of 3- to 17-year-olds, 15% had a history of nocturnal tooth grinding. Abe and Shimakawa (1966) reported that 11.6% of their 3-year olds were tooth grinders. Lindqvist (1971) examined 196 children for evidence of bruxing and grinding behavior. The children ranged in age from 10.7 years to 13.1 years with an average of 11.8 years. Parents reported that approximately 14.9% of them had heard their children grind their teeth.