Abstract
Thumb sucking is an abnormal habit that occurs in childhood and can cause several malocclusions if it persists for a long time. Malocclusions caused by oral habits require proper treatment timing to maintain a normal growth and should be treated at an early age. This case report shows the management of thumb sucking and early correction of anterior open bite and posterior crossbite by a modified Haas expander. Three-year follow-up results showed the effectiveness of this special designed appliance.
Keywords: Thumb sucking, Modified Haas expander, anterior openbite, posterior crossbite, tongue crib
INTRODUCTION
Abnormal oral habits are repetitive actions that may lead to disturbance in physical growth depending on their frequency, duration, and intensity (1). Thumb or finger-sucking is one of the most common oral habits practiced by children, occurring in approximately 17% of them (2, 3). Malocclusion prevalence studies have established that prolonged thumb sucking may cause specific abnormal effects on occlusion, surrounding bone development and orofacial musculature function (4, 5).
Traisman (6) reported a highly significant difference in the number of malocclusions, with 9.7% in thumb-suckers compared with 6.7% in non-thumb-suckers. Thumb sucking for extended periods can lead to various types of malocclusion including anterior open bite, posterior crossbite, increased overjet, crowding, and increased probability of developing a Class II malocclusion (7).
The main cause of posterior crossbite in thumb-suckers is alteration of the functional equilibrium between the tongue and orofacial musculature (8). This imbalance leads to the narrowing of the maxillary arch that results with a posterior crossbite.
Intense habits can deform the alveolus and dentition during the primary dentition years (9). Finger pressure can impede the eruption of the permanent incisors and cause anterior open bite. Most of the changes resolve spontaneously as soon as the habit stops before the eruption of the permanent incisor.
Here, we report a case of a thumb-sucker patient with anterior open bite and posterior crossbite in the early mixed dentition stage.
CASE PRESENTATION
Diagnosis
An 8-year- and 4-month-old male patient accompanied by his parents was referred to the Department of Orthodontics with a chief complaint of prolonged thumb sucking (Figure 1). The patient was in the early mixed dentition stage. No pathological background information was reported according to his medical history.
Figure 1.
Thumb sucking position
Unilateral posterior crossbite, 3.5 mm anterior open bite, slight midline deviation to the left, and a constructed maxillary arch were revealed on complete clinical examination. He presented a Class I molar relationship on the right side and Class II on the left side (Figure 2).
Figure 2.
Pretreatment (T0) extraoral and intraoral photographs
His anamnestic information revealed that his sucking habit lasted all night long; however, he stopped the habit when someone reminded him during daytime.
His skeletal and alveolar structures appeared to be normal in panoramic radiographs. Cephalometric analysis showed that both the maxilla and the mandible were protrusive relative to SN, whereas the ANB angle was 6° (Figure 3 and Table 1). Although the patient had an anterior open bite, he a skeletally low angle. The lower incisors were proclined due to the altered type of thumb sucking pressure on them.
Figure 3.
Cephalometric radiographs
Table 1.
Cephalometric measurements
| Parameter | Norm | Pretreatment T0 |
Posttreatment T1 |
3-year follow-up T2 |
|---|---|---|---|---|
| SNA (°) | 80±2 | 92.1 | 91.7 | 90.8 |
| SNB (°) | 78±2 | 86.0 | 84.8 | 86.5 |
| ANB (°) | 2±2 | 6.0 | 6.9 | 4.3 |
| Wits (mm) | 0±1 | 2.1 | 0.9 | −0.7 |
| SN-GoGn (°) | 32±6 | 26.0 | 28.3 | 24.0 |
| FMA (°) | 25 | 18.5 | 17.7 | 15.8 |
| U1-PP (°) | 112±6 | 117.6 | 115.3 | 114.0 |
| IMPA (°) | 90±3 | 106.5 | 97.2 | 93.2 |
| U1-NA (mm) | 4.0 | −1 | 0.8 | 3.3 |
| L1-NB (mm) | 4.0 | 7.5 | 5.6 | 4.6 |
| UL-E (mm) | −4 | 0 | −0.1 | −2.2 |
| LL-E (mm) | −2 | 1.4 | 1.6 | −0.9 |
Treatment goals
The main goals of treatment were breaking the habit, correcting posterior crossbite, providing the necessary environment for permanent teeth eruption, and obtaining normal overbite.
Written informed consent was obtained from the parents of the patient.
Treatment plan and progress
A special appliance was designed by modifying the Haas expander for preventing thumb sucking and expanding the maxilla at the same time (Figure 4). This expander was anchored to the deciduous second molars and canines. A tongue crib, which was used to help break the habit, was attached to the anterior arms of the expander behind the anterior teeth. The crib was covered with acrylic making it smoother and was split into two so as not to prevent the expansion. The patient’s mother was instructed to activate the screw two turns per day in the first 10 days and then once a day. Expansion was performed until transverse overcorrection was obtained on the deciduous molars. After completion of the active expansion phase, the expander was kept in the mouth for 6 months for retention of the expansion and ensuring that the habit has truly stopped.
Figure 4.
Modified Haas expander with tongue crib
Treatment Results
Posterior crossbite was corrected successfully, including the permanent molars, even though no direct forces were applied on them. When the proper transverse dimension was achieved in the maxilla, the mandible returned to its normal position, resulting in spontaneous correction of the midline and a Class II molar relationship on the left side (Figure 5).
Figure 5.
Posttreatment (T1) extraoral and intraoral photographs
Thumb sucking was reduced significantly in the first weeks with the appliance and was prevented completely at the end of the first month. The delayed permanent anterior teeth eruption was normalized when finger pressure was eliminated.
The appliance was removed at the end of 6 months and was recalled for follow-up visits at 3-month intervals for 3 years (Figure 6).
Figure 6.
Three-year follow-up (T2) extraoral and intraoral photographs
The overall treatment resulted in a slight posterior rotation of the mandible. The ANB angle showed a slight increase after expansion, whereas the SNA angle remained unchanged. During the follow-up period, mandibular growth was mainly in an anterior direction, resulting in an increase in SNB angle and a decrease in ANB angle (Table 1). Proclined lower incisors were found to tip lingually at the end of the treatment and continued with increasing age (Figure 7).
Figure 7.
Cephalometric superimposition
DISCUSSION
The period between age 3 and 6 years is the transitional period for addressing potential oral habits (10). Abnormal oral habits, such as thumb sucking, should be decreased significantly by the end of this period. If the habit is not eliminated before the permanent incisors erupt, it leads to considerable malocclusions, especially for those who continue the habit for a duration of ≥6 h/day (11).
Our patient was in the early mixed dentition stage and had already anterior open bite because of thumb sucking. Many studies have reported that if the habit is stopped during the mixed dentition years, some of the adverse dental changes will begin to reverse naturally (10, 12). At the end of 6 months of treatment, anterior open bite was corrected spontaneously due to increased growth of the alveolar processes and eruption of the permanent incisors.
In contrast to anterior open bite, posterior crossbite is not a self-correcting malocclusion and should be treated early to avoid the negative long-term effects on growth and development of the teeth and jaws (13). Our patient had unilateral posterior crossbite in the left side that was corrected with a modified Haas expander.
Routine orthodontic treatment protocols require more than one appliance to break the habit and correct the malocclusion. Orthodontic approaches with more than one appliance increase treatment time and costs. The present design used in this case was effective in the correction of anterior open bite and posterior crossbite at the same time. On the other hand, as compared with conventional rapid palatal expansion appliances, the expander was anchored on deciduous teeth to prevent any damage or negative effects to permanent teeth.
CONCLUSION
The long-term stability of crossbite and open bite correction associated with thumb sucking in the mixed dentition was favorable. The unique design of the appliance provided an opportunity to resolve three major problems with one appliance and can be preferred as a convenient alternative to conventional habit breakers.
Footnotes
Informed Consent: Written informed consent was obtained from the parents of the patient who participated in this study.
Peer-review: Externally peer-reviewed.
Author Contributions: Concept - N.M., A.A.Ö.; Design - N.M., A.A.Ö.; Supervision - N.M., A.A.Ö.; Materials - N.M., A.A.Ö.; Data Collection and/or Processing - N.M., A.A.Ö.; Analysis and/or Interpretation - N.M., A.A.Ö.; Literature Search - N.M., A.A.Ö.; Writing Manuscript - N.M., A.A.Ö.; Critical Review N.M., A.A.Ö.
Conflict of Interest: The authors have no conflict of interest to declare.
Financial Disclosure: The authors declared that this study has received no financial support.
REFERENCES
- 1.Mendoza Oropeza L, Meléndez Ocampo AF, Ortiz Sánchez R, Fernández López A. Prevalence of malocclusions associated with pernicious oral habits in a Mexican sample. Rev Mex Ortod. 2014;2:e216–23. doi: 10.1016/S2395-9215(16)30151-9. [DOI] [Google Scholar]
- 2.Fukuta O, Braham RL, Yokoi K, Kurosu K. Damage to the primary dentition resulting from thumb and finger (digit) sucking. ASDC J Dent Child. 1996;63:403–7. [PubMed] [Google Scholar]
- 3.Littlefield WH. Thumb-sucking and its relationship to malocclusion in children. Am J Orthod. 1952;38:293–300. doi: 10.1016/0002-9416(52)90122-X. [DOI] [Google Scholar]
- 4.Warren JJ, Bishara SE. Duration of nutritive and nonnutritive sucking behaviors and their effects on the dental arches in the primary dentition. Am J Orthod Dentofac Orthop. 2002;121:347–56. doi: 10.1067/mod.2002.121445. [DOI] [PubMed] [Google Scholar]
- 5.Alonso Chevitarese AB, Della Valle D, Moreira TC. Prevalence of malocclusion in 4–6 year old Brazilian children. J Clin Pediatr Dent. 2003;27:81–5. doi: 10.17796/jcpd.27.1.an436m284201571p. [DOI] [PubMed] [Google Scholar]
- 6.Traisman AS, Traisman HS. J. Pediatrics Thumb- and finger-sucking: A study of 2,650 infants and children. Am J Orthod Dentofac Orthop. 1959;45:381–3. doi: 10.1016/0002-9416(59)90167-8. [DOI] [PubMed] [Google Scholar]
- 7.Nanda RS. Effect of oral habits on the occlusion in preschool children. J Dent Child. 1972;39:449–52. [PubMed] [Google Scholar]
- 8.Vinay C, Sandeep V, Hanumanth Rao CH, Uloopi KS, Kumar AS. Modified quad helix appliance for thumb sucking and cross bite correction. Contemp Clin Dent. 2013;4:523–6. doi: 10.4103/0976-237X.123064. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Proffit WR, Fields HW, Sarver DM. Treatment of Nonskeletal Problems in Proadolescent Children: Contemporary Orhtodontics. 2007:433. [Google Scholar]
- 10.Nowak AJ, Christensen JR, Mabry TR, Townsend JA. Wells MHBT-PD Oral Habits. Philadelphia: 2019. pp. 386–393. [Google Scholar]
- 11.Proffit WR. Lingual pressure patterns in the transition from tongue thrust to adult swallowing. Arch Oral Biol. 1972;17:555–63. doi: 10.1016/0003-9969(72)90071-4. [DOI] [PubMed] [Google Scholar]
- 12.Larsson E. Artificial sucking habits: etiology, prevalence and effect on occlusion. Int J Orofacial Myology. 1994;20:10–21. [PubMed] [Google Scholar]
- 13.Petren S, Bjerklin K, Bondemark L. Stability of unilateral posterior crossbite correction in the mixed dentition: a randomized clinical trial with a 3-year follow-up. Am J Orthod Dentofacial Orthop. 2011;139:73–81. doi: 10.1016/j.ajodo.2010.06.018. [DOI] [PubMed] [Google Scholar]