Dr. Neveen Monaem Dr. Ramadan Abu-Shahba

1. Journal of Pharmaceutical Negative Results ¦ Volume 13 ¦ Special Issue 10 ¦ 2022 2281
Assessment Of Class 3 Management With
Orthodontic Tongue Crib Appliance: Prospective
Cephalometric Study
Neveen AbdalMonaem1
, Ahmed Shehata2
, Elhassanein Haussein2
, Ahmed Abouelnour3
, Ramadan Yusuf Abu-Shahba3
1. Orthodontic trainer, Egyptian fellowship of family dentistry, Almonira general hospital, Ministry of Health and
population, Cairo, Egypt.
2. Lecturer, Department of Orthodontics, Faculty of Dental Medicine, Al-Azhar University, Cairo, Egypt.
3. Associate professor, Department of Orthodontics, Faculty of Dental Medicine, Al-Azhar University, Cairo, Egypt.
266
10.47750/pnr.2022.13.S10.
DOI:
Objectives The aim of the study was assessment the orthodontic tongue crib efficiency for treating skeletal class 3 and open bite
malocclusion in growing children by cephalometric measurements analysis. Materials and Methods The sample comprised of 18
growing children with class 3 of deficient maxilla and anterior open bite malocclusion. The patients (boys 5 and girls 13 with mean
age 8.89° ± 1.6 years) were treated with fixed tongue crib and tongue exercise therapy. Lateral cephalograms were arranged and
analyzed before treatment and after 12 months for comparing the skeletal changes of the craniofacial structures. Results After 12
months of treatment with the tongue crib appliance, all patients got a favorable facial profile and lip closure improved, and positive
overjet was achieved. Anterior crossbite as well as open bite, and upper and lower first molars relationships were improved. In
cephalometric measurements analysis revealed that significant forward growth of the maxilla exhibited in a statistical increase of
SNA, maxillary depth p<0.001(SNA angle had increased from 78.75° to 81.12° and ANB angle had changed from 0.3° to +2.25°).
The mandible revealed slightly significant increase in facial angle from 83.75° to 84.94° and non- significant change of SNB.
Regarding vertical changes, growth was shown significant as increase in FMA, SN-PP, and ANS-Me. ConclusionsTongue crib
appliance is an effective device for the patients in the growing period with skeletal Class 3 and open bite malocclusions, by improving
the maxillary complex growth. Orthodontic Tongue crib appliance might be an alternative method to facemask extra-oral appliances.
Key words: Orthodontic Tongue crib, Maxillary Deficiency, Open Bite, Cephalometric Analysis
INTRODUCTION
Orthodontics aims to direct the normal facial growth and guide the dentition to erupt in a good occlusion. Early
management of developing skeletal malocclusions give a chance to redirect the growth vector and avoid orthognathic
surgery in advance.
Rogers, related the normal development of the face, jaw, and dentition to the normal functional balance of the Oro-
facial muscles7
. Facial growth is guided by the muscles and soft tissue of the face. Accordingly, when muscle or soft
tissue dysfunction occurred, facial growth is altered. The dysfunction may be tongue thrust swallowing, mouth
breathing or thumb sucking.4,8
Graber, analyzed the relationship of muscles and their configuration in Class I, Class II, and Class III malocclusions.
He reported that, the effect of muscle forces is three-dimensionally. He emphasis that; the orthodontist appraises muscle
activity, and he has to conduct his orthodontic therapy in such a manner that the finished result reflects a balance
between the structural changes obtained and the functional forces acting on the teeth and investing tissues at that time.3
Ahrari and Eslami Their case report describes orthodontic treatment of a patient with skeletal Class III malocclusion
with maxillary hypoplasia. The treatment plan included an intra-oral removable device. They achieved forward growth
of the maxilla, minimal downward and backward rotation of the mandible and improved facial profile esthetics.1
Zhao, Chen, Kyung, and Xu evaluated the treatment effects of tongue crib combination for treating severe skeletal
Angle class III malocclusion in mixed dentition by X-ray cephalometric analysis. They concluded, the tongue crib
combination is an effective device for the patients in the growing period with skeletal Angle class III malocclusion by
improving the maxillary growth and limiting the mandibular growth.9
Almost of published documents are case reports, so the present study conducted to be an article concerned with the
evaluation of orthodontic tongue guard skeletal effects used for treating skeletal class 3 and open bite malocclusion in

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growing children through cephalometric analysis.
Materials and Methods
The sample collected from Orthodontic Outpatient Clinics of Almoneira General Hospital, Ministry of Health and
population and Faculty of Dental Medicine, Al-Azhar University. Ethical approval of this study was obtained from the
Ethical Committee of the Faculty of Medicine, Al-Azhar University and the research objectives were full discussed to
the guardians and informed consents were obtained before commencing the study.
The study and the selection of patients were conducted with the following inclusion criteria; Healthy children of age
range 8 to 11 years old. Skeletal Class 3 with/without anterior open bite malocclusion. Presence of fully erupted
completely root formed maxillary first molars. Good oral hygiene and cooperation. The exclusion criteria were taken
into consideration; Careless or uncooperative child and annoyers parents, but no one was excluded
For each patient, the following diagnostic records; Extraoral and intraoral photographs, Orthodontic study model,
panoramic radiograph, and lateral cephalometric radiograph were taken before and after one year of using orthodontic
tongue crib appliance as well as patient examination sheet and Informed consent.
The control group comprised seven children, where they make cephalometric radiographs and dismissed for ten months
due to covid-19 pandemic situation, then they revised again to start the treatment and remake the new records.
So, the sample of study group comprised eighteen growing children with class 3 of deficient maxilla and anterior open
bite malocclusion. The patients (boys 5 and girls 13 with mean age 8.89 ± 1.6 years) were treated with fixed tongue
guard and tongue exercise therapy.
Lateral cephalograms were arranged and analyzed before treatment and after 12 months for comparing the skeletal
changes of the craniofacial structures.
Reliability of the analyzed data (Measurement error analysis)
To determine the intra-examiner; a second set of measurements was performed of all cephalometries after 3 weeks from
the first measurements. The intra-observer ratability test results for all the studied variables revealed a non-significant
difference between the first and second measurements, indicating high reliability of all measurements carried out by
the same examiner.
Statistical analysis performed by SPSS 22 and paired t-test was used to evaluate the treatment changes on T0 and T1
measurements.
Figure (1) Pre-treatment and post-treatment extra-oral and intra-oral photographs for a case with
class 3 and open bite malocclusion

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Results
After 12 months of treatment with the tongue crib appliance, all patients got a favorable facial profile and lip closure
improved as well as upper and lower first molars relationships were assumed class I occlusion. Statistical analysis
summarized in table 1 and histogram 1 to describing the data of cephalometric measurements and testing the changes
between before and after installing orthodontic tongue crib appliance for 12 months. Cephalometric measurements
analysis revealed significant forward growth of the maxilla exhibited in a statistical increase of SNA, maxillary depth
p< 0.001 (SNA angle had increased from 78.75° to 81.12° and ANB angle had changed from 0.3° to +2.25°). The
mandible revealed slightly significant increase in facial angle from 83.75 to 84.94 and non-significant change of SNB.
Regarding vertical changes, growth was shown significant as increase in FMA, SN-PP, and ANS-Me. Positive overjet
was achieved. Anterior crossbite as well as open bite, were improved. For the linear measurements, there was a
significant decrease in the lower anterior facial height.
Figure (3) The cephalometric superimposition for three cases with different progression rate, the mean is the middle.
Figure (2) Lateral cephalometric radiographic views represent a case with class 3 and open bite malocclusion
a) pretreatment and b) posttreatment with orthodontic tongue guard appliance.

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Table (1) Descriptive statistics and Paired t-test for pre-treatment (T0) and post-treatment (T1) for lateral
cephalometric measurements the study group:
Mean S. D. Paired Differences t-value Sig.
Mean S. D.
SNA 0 78.7500 3.6423 -2.3750 1.0878 -8.733 0.000***
SNA 1 81.1250 3.8275
SNB 0 78.3750 3.3838 0.5000 1.4142 1.414 0.178NS
SNB 1 77.8750 3.6674
ANB 0 0.3750 2.3058 -1.8750 1.6683 -4.496 0.000***
ANB 1 2.2500 1.6931
Y-axis 0 61.9375 3.8204 0.8125 4.1023 0.792 0.441NS
Y-axis 1 61.1250 1.4083
FMA 0 33.6250 5.9986 1.6250 3.1807 2.044 0.059*
FMA 1 32.0000 3.7947
SN-PP 0 9.1333 2.6957 -1.8667 2.5033 -2.888 0.012**
SN-PP 1 11.0000 3.1848
Gonial 0 130.5000 6.0222 0.5000 4.7329 0.423 0.679NS
Gonial 1 130.0000 4.4422
LAFH 0 58.0875 2.1011 2.0625 2.8237 2.922 0.011**
LAFH 1 56.0250 1.3051
PFH 0 59.0000 5.3429 -0.9250 2.5710 -1.439 0.171NS
PFH 1 59.9250 4.6258
Max.Depth 0 86.5000 3.3066 -2.6250 1.7842 -5.885 0.000***
Max.Depth 1 89.1250 2.8954
Facial angle 0 83.7500 3.7859 -1.1875 1.4245 -3.335 0.005***
Facial angle 1 84.9375 3.9576
NS= Non Significant at P > 0.05, *= P<0.05, **= P<0.01, ***= P<0.001
Figure (4) The histogram for the mean of pre-treatment (T0) and post-treatment (T1) cephalometric measurements
for the study group.
A comparative statistic was made between study and control group and summarized in table 2. It showed statistically
significant difference in SNA, ANB and maxillary depth angles in a sagittal direction. Also, there was a significant
difference in vertical direction (Gonial angle).
Table (2) Comparison of the lateral cephalometric skeletal changes in pre-treatment (T0) and post-treatment (T1)
measurements for the mean differences between the study and control groups (independent sample t-test):
Study group Control group p value
Mean SD p value Mean SD p value
SNA 2.32 1.96 3.521 -0.28 0.13 1.514 0.015**
SNB -1.98 2.68 0.165 0.07 0.06 0.149 0.432
ANB 2.17 1.89 0.131 -0.74 0.93 0. 281 0.018**
Y-axis −0.28 0.58 1.253 0.66 0.17 0.972 1.043
FMA 1.64 1.17 0.021 0.27 1.08 1.063 0.496
SN-PP −0.61 1.46 0.045 0.32 0.94 0.065 0.963
Gonial 1.57 1.39 0.634 0.28 1.03 0.634 0.056*
LAFH 3.41 0.64 0.057 1.77 0.34 0.986 0.281

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PFH 2.85 0.22 0.038 2.84 0.47 1.165 0.087
Max. Depth 2.73 1.34 0.057 1.71 1.27 1.672 0.049*
Facial angle 0.56 1.25 0.088 0.97 0.14 2.987 0.134
*= P<0.05, **= P<0.01, ***= P<0.001
Discussion
The present cephalometric prospective study evaluated the effectiveness of the orthodontic tongue crib for treating the
patients with skeletal class III with or without open bite malocclusion in the growing stages and comparing with the
changes with control group. This study was designed where the patients with class III malocclusion that were treated
by tongue crib got a more favorable facial profile clinically than that by other treatment modalities. All patients in that
study group revealed a significant facial profile after treatment.
The skeletal parameters: Regarding the maxilla; There was a significant increase of SNA angle, For the mandible;
There was a decrease in SNB but its statistically non-significant. For the intermaxillary relationship, it could be seen
here a significant increase of the ANB angle, which indicates an improvement of the skeletal discrepancy.
Their overjet increased obviously with the treatment, from negative to positive figure. The main interpretation for the
improvement was due to a maxilla growth forward. The limitation of the mandibular growth played some effects.
The outcomes from the cephalometric measurement in the present cephalometric study revealed significant sagittal
facial and skeletal improvements, such as the maxilla (SNA +2.32°) and control of mandibular position (SNB −1.98°)
and maxillomandibular relationship (ANB +2.17°) when compared to the control group. These progressions were found
to be similar to the data in the other study1
in that an increase in SNA (2.23°), reduction in SNB (−1.33°), and
improvement of ANB (+3.81°) was found by the use of miniplates as a skeletal anchorage for maxillary protraction in
the group of growing class III patients maxilla deficiency. The result of the present study were higher than the findings9
reported on class III treatment with splint, class III elastics, and chin-cup in a sample of class III growing patients
(SNA +1.2°, SNB −1.3°).
The vertical skeletal height revealed significant differences in the study group. These findings were consistent with the
outcomes of chin-cup and skeletal anchorage protraction therapy2,6
and suggested that orthodontic tongue crib might
minimize the open rotation of mandible in the case of class III malocclusion in a growing period. Some studies5
reported
the rotations of the maxilla and mandible often happened in protraction and class III elastics.
Disclosure statement
The current study is self-funded, and the investigators had no conflict of interest or financial benefits concerning the
current study results.
Conclusions
1. Tongue crib appliance is an effective device for the growing patients with skeletal Class 3 and open bite
malocclusions, by improving the maxillary growth.
2. Clinically the patient’s frontal and profile esthetic view is obviously improved.
3. Tongue crib appliance prove its sagittal and vertical effects on the maxilla.
4. Although the effects of the tongue guard on the mandible are statistically non-significant but its clinically
significant.
5. Orthodontic Tongue crib appliance might be an alternative method for facemask extra-oral appliances.
References
1. Ahrari F and Eslami N: Nonsurgical Treatment of Maxillary Deficiency Using Tongue Guard Appliance: A Case Report. J Dent Res Dent Clin
Dent Prospects 2011; 5(4):136-40.
2. Bozkaya E, Yu¨ksel AS, Bozkaya S. Zygomatic miniplates for skeletal anchorage in orthopedic correction of class III malocclusion: a controlled
clinical trial. Korean J Orthod 2017;47(2):118–29.
3. Graber TM: The "three M's": Muscles, malformation, and malocclusion. Am J Orthodontics. 1963; 49(6): 418-50.
4. Lee HS, Choi HM, Choi DS, et al. Bone thickness of the infrazygomatic crest area in skeletal class III growing patients: A computed tomographic
study. Imaging Sci Dent 2013;43(4):261–6.
5. Meyns J, Brasil DM, Mazzi-Chaves JF, et al. The clinical outcome of skeletal anchorage in interceptive treatment (in growing patients) for class
III malocclusion. Int J Oral Maxillofac Surg 2018;47(8):1003–10.
6. Perillo L, Vitale M, Masucci C, et al. Comparisons of two protocols for the early treatment of class III dentoskeletal disharmony. Eur J Orthod
2016;38(1):51–6.
7. Rogers AP.: Exercises for the development of the muscles in the face, with a view to increasing their functional activity. Dental Cosmos. 1918;
60, 857-76.
8. Soo ND, Moore RN. A technique for measurement of intraoral lip pressure with lip bumper therapy. Am J Orthod 1991;99(5):409–17.
9. Zhao W, Chen Y, Kyung H, Xu J: Effectiveness of Tongue Crib Combination Treating Severe Skeletal Angle Class III Malocclusion in Mixed
Dentition. International Journal of Clinical Pediatric Dentistry, 2020; 22, 463–74.

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10. Meyer-Marcotty P, Hartmann J, Stellzig-Eisenhauer A. Dentoalveolar open bite treatment with spur appliances. J Orofac Orthop. 2007; 68:510-
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11. Van Dyck C, Dekeyser A, Vantricht E, Manders E, Goeleven A, Fieuws S, Willems G. The effect of orofacial myofunctional treatment in
children with anterior open bite and tongue dysfunction: a pilot study. Eur J Orthod. 2016; 38:227-34.