|Year : 2009 | Volume
| Issue : 2 | Page : 94-103
Effectiveness of circumoral muscle exercises in the developing dentofacial morphology in adenotonsillectomized children: An ultrasonographic evaluation
UM Das, JP Beena
Department of Pedodontics and Preventive Dentistry, V. S. Dental College and Hospital, K. R. Road, V. V. Puram, Bangalore-560 004, Karnataka, India
|Date of Web Publication||31-Aug-2009|
U M Das
Department of Pedodontics and Preventive Dentistry, K.R. Road, V.V. Puram, Bangalore-560 004, Karnataka
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Alterations in the functions of the facial muscle can establish changes in facial skeleton and in the development of occlusion. The effect of mouth breathing on the facial morphology is probably greatest during the growth period. Removal of nasal obstruction, adenoids, and tonsils have not given beneficial results in the reversion of the habit unless intercepted with various muscle exercises. Hence, this study was conducted to ultrasonographically evaluate the effectiveness of circumoral muscle exercises in the developing dentofacial morphology in adenotonsillectomized children.
Keywords: Adenotonsillectomized, circumoral, mouth breathing, ultrsonography
|How to cite this article:|
Das U M, Beena J P. Effectiveness of circumoral muscle exercises in the developing dentofacial morphology in adenotonsillectomized children: An ultrasonographic evaluation. J Indian Soc Pedod Prev Dent 2009;27:94-103
|How to cite this URL:|
Das U M, Beena J P. Effectiveness of circumoral muscle exercises in the developing dentofacial morphology in adenotonsillectomized children: An ultrasonographic evaluation. J Indian Soc Pedod Prev Dent [serial online] 2009 [cited 2021 Apr 22];27:94-103. Available from: https://www.jisppd.com/text.asp?2009/27/2/94/55334
| Introduction|| |
The role of orofacial muscles in determining facial morphology and tooth position has intrigued dental researchers for decades. Our present knowledge of the anatomy of the mimic muscle, including the circumoral musculature, is based on an extensive series of cadaver preparations. While they yield a general description of the form and distribution of muscle within the circumoral soft tissue, none provide an accurate description between the contraction and relaxation of the muscle and of the change in the shape of the soft tissue during function. 
The theory advanced by Tomes almost 100 years ago was that it is the perioral musculature and the tongue, which principally determined the position of the teeth, that has long been accepted by the dental profession. As he puts it "The agency of the lips and tongue is that which determines the position of the teeth themselves."
Nasal breathing enables adequate growth and development of the craniofacial morphology, which interacts with other functions such as chewing and swallowing.  Alterations in the soft tissues have been attributed to mouth breathing, more specifically modification in muscle functions, as well as in the hard tissue morphology, including facial bones and dental arches.  Obstructive adenoids and tonsils, which are the major causes of chronic mouth breathing, alter the dentition and dental arches. ,,
During the growth phase, the child with chronic mouth breathing, whether caused by nasal obstruction or not, develops several morphological alterations, that lead to an undesirable development of the dentofacial complex morphology. , As the obstruction of the upper airways is an important variable that can initiate these skeletal alterations, early recognition and treatment of pathological conditions that cause obstruction of airways have been recommended. 
The lips have been described only as hypotonic or hypertonic, these terms being mainly subjective, and the relationship between lip competency and malocclusion has also not come under serious scrutiny though everyone is keen to see how small or great is the influence of the lip musculature on the dentition.
Rogers  was among the first to recommend the use of muscles to correct malocclusion. The essence of myofunctional therapy was to use the muscle activity as a primary source of force for resolution of malocclusion. Reports confirm that removal of nasal obstruction, adenoids, and tonsils has not given beneficial results in the reversion of habit, and improvement in tone, and the development of the circumoral musculature.
Rogers  concluded from his studies that the problem of overcoming the mouth breathing habit is through giving exercise to the involved muscles. Proper systematic exercise alone was found to be more effective than any other method to produce a harmonious development.
Frankel  in his study stressed the importance of lip seal therapy or exercises using functional regulator devices, which have been effective in improving the poor posture of the whole of orofacial musculature. These therapies or exercises are suitable means of activating and improving the tone and thickness of the muscles creating a lip seal, suspending the mandible in a proper postural position and helping the patient acquire normal habits.
Ultrasound imaging has been used to study movements of the tongue, floor of the mouth, hyoid bone, and larynx. Ikai et al.  and Dons et al.  have used ultrasound to measure muscle size as a result of weight lifting.
Prabhu and Munshi  in a study of ultrasonographic observation of the circumoral musculature with varying classes and types of malocclusions found definite changes in the thickness of circumoral muscle in the relaxed and contracted states in various malocclusion states and also found definitive changes in muscle thickness after patients were given muscle exercises.
The effects of mouth breathing on orofacial musculature is greatest during growth period. This justifies the need for further investigations on children using ultrasound to evaluate the effectiveness of muscle exercises in circumoral musculature in adenotonsillectomized children.
To determine the thickness of circumoral musculature ultrasonographically in children with mouth breathing due to adenoids and/or tonsils prior to adenotonsillectomy.
To compare the thickness of circumoral musculature measured ultrasonographically, of the experimental groups, who have done lip seal therapy and exercises with oral screen for 6-month period, with the control group who have not done exercises during this period following adenotonsillectomy.
To establish the degree of improvement in lip seal clinically and ultrasonographically, in adenotonsillectomized experimental group children after prescribed 6 months lip seal therapy and exercises with oral screen.
| Materials and Methods|| |
A total of 30 children (15 boys and 15 girls) aged between 7 and 12 years visiting the Department of ENT, Kempegowda Institute of Medical Sciences, Bangalore, and Department of Pedodontics and Preventive Dentistry, V.S.Dental College and Hospital, Bangalore, who were confirmed to have the enlargement of adenoids and tonsils fulfilling the inclusion and exclusion criteria were selected based on clinical and radiographic examination. Prior to imaging, each subject was given a dental clinical examination, including observations on changes in the external contours of the lips were recorded on standardized frontal and profile photographs. Shape of the face, lip thickness--stiffness, lip competency, perioral tonicity, number of teeth present, caries teeth, root stumps, missing teeth, and restored teeth were also recorded. Dental treatment, including prophylaxis, preventive, and restorative treatment, was done.
The patients were divided into two groups following surgery.
Group A: Control group, who have not done exercises following surgery (eight boys and seven girls).
Group B: Experimental group, who have done lip seal therapy and exercises with oral screen for a period of 6 months following surgery (seven boys and eight girls)
Inclusion criteria: Children in the age group of 7-12 years with enlarged adenoids and tonsils.
Exclusion criteria: Mouth breathing due to reasons other than enlarged adenoids and tonsils.
Prior to the surgery: Lateral oblique view of the skull is taken to confirm the presence of adenoid enlargement. All the patients are sent for ultrasonographic evaluation of the circumoral musculature.
After adenotonsillectomy: Patients in experimental group were shown exercises using oral screen (Dentaurum) R and a set of lip seal therapy as shown in [Figure 1],[Figure 2],[Figure 3],[Figure 4],[Figure 5].
All these exercises were done for 15-20 times for four times a daily. These exercises would help in lip strengthening, lengthening, lip mobility, and improving lip closure.
Patient compliance and active involvement and co-operation of the parents were utmost important in this study. The parents were asked to maintain a record of the number of times the exercises were done and the record was brought during every recall appointment for the doctor's approval, depending on which suitable reinforcers were given to the child.
Ultrasonographic evaluations were done at the Department of Radio diagnosis in Kempegowda Institute of Medical Sciences, Bangalore, using Volvson 730 PRO with superficial probe SP of 6-12 mHz. Scan of the upper and lower lip in relaxed and contracted states was done. As a linear probe was used, the entire area of upper or lower lip was covered for taking the image at a single stretch.
From the image, the thickness of the lip in the center as well as in periphery on both sides of the upper and lower lips in contracted and relaxed states were measured. The state of contraction was standardized by having the subject hold a 'V'-shaped piece of tracing paper between the lips and the two halves of the fold were in contact with one another by lip contraction.
Upper and lower lips were divided into three portions, right, middle, and left (R.M.L) for the convenience of scanning, and the measurements were taken in millimeters. After the 6-month therapy period, the ultrasonographic evaluation was repeated. No sedation or premedication was given to these patients, as all of them were very co-operative.
At the end of 6 months, the thickness of circumoral musculature in both the groups was measured ultrasonographically. The data were analyzed statistically using the Students ' t '-test [Figure 6],[Figure 7],[Figure 8],[Figure 9],[Figure 10].
| Results|| |
Comparison of lip thickness
The lip thickness in the relaxed and contracted positions (for both upper and lower lip) was compared between the pre-operative and post-operative time intervals using the t -test.
We notice that there is no significant difference between the experimental group and the control group with respect to the lip thickness in pre-operative ( P >0.05). However, there is a significant difference in the post-operative time interval ( P <0.001).
There is no significant difference in the upper lip thickness in the contracted position between the two groups in the pre-operative time interval ( P >0.05), but there is a significant difference in the post-operative time interval ( P <0.001).
We see that there is no significant difference between the two groups with respect to the lower lip thickness in the relaxed position in the pre-operative time interval ( P >0.05). However, there is a significant difference between the two groups in the post-operative time interval ( P <0.001).
We observe that there is no significant difference between the two groups in the lip thickness of the lower lip in the contracted position at pre-operative time interval ( P >0.05). However, we see a significant difference at post-operative time interval ( P <0.001).
[Table 1] shows that the mean difference between the experimental and control groups at the pre-operative interval, for the upper lip in the relaxed position was
- 0.517 and at the post-operative interval it was -1.372. We noticed that there was no significant difference between the experimental group and the control group with respect to the lip thickness in the pre-operative time interval ( P >0.05), but there was a significant difference in the post-operative time interval ( P <0.001)
[Table 2] shows that the mean difference between the experimental and control groups at the pre-operative interval, for the upper lip in the contracted position was -0.201 and at the post-operative interval it was -1.056. Hence, there was no significant difference in the upper lip thickness in the contracted position between the two groups in the pre-operative time interval ( P >0.05), but there was a significant difference in the post-operative time interval ( P <0.001).
[Table 3] shows that the mean difference between the experimental and control groups at the pre-operative interval for the lower lip in the relaxed position was -0.260 and at the post-operative interval it was -1.151. Hence, there was no significant difference between the two groups with respect to the lower lip thickness in relaxed position in the pre-operative time interval ( P >0.05), but there was a significant difference between the two groups in the post-operative time interval ( P <0.001).
[Table 4] shows that the mean difference between the experimental and control groups at the pre-operative interval for the lower lip in the contracted position was -0.148 and at the Post-operative interval it was -1.045. We observe that there was no significant difference between the two groups in the lip thickness of the lower lip in the contracted position at the Pre-operative time interval ( P >0.05), but there was a significant difference at the post-operative time interval ( P <0.001).
In our study, we found that there was a significant difference in the pre-operative and post-operative lip thickness in the upper lip relaxed position (experimental group) among males ( P <0.001) and females ( P <0.01) as shown in [Table 5] and that there was a significant difference in the pre-operative and post-operative lip thickness in the upper lip contracted position (experimental group) among males ( P <0.01) and females ( P <0.05). There was no significant difference in the pre-operative and post-operative lip thickness in the upper lip relaxed position (control group) among males ( P >0.05) and females ( P >0.05).
We observed that there was no significant difference in the pre-operative and post-operative lip thickness in the, upper lip relaxed position (control group) among males ( P >0.05) and females ( P >0.05) and that there was a significant difference in the pre-operative and post-operative lip thickness in the lower lip relaxed position (experimental group) among males ( P <0.001) and females ( P <0.01).
We found that there was a significant difference in the re-operative and post-operative lip thickness in the lower lip contracted position (experimental group) among males ( P <0.001) and females ( P <0.001) and noticed that there was no significant difference in the pre-operative and post-operative lip thickness in the lower lip relaxed position (control group) among males ( P >0.05) and females ( P >0.05) as shown in [Table 5].
We notice that there was a significant difference in the pre-operative and post-operative lip thickness in the lower lip contracted position (control group) among males ( P >0.05) and females ( P >0.05).
| Discussion|| |
Respiration is essential for the maintenance of life and it is also an important function related to dentofacial development when considering the breathing pattern. ,,,, The effects of mouth breathing include alterations in the muscles, function, posture, bone, and behavior. , If this occurs during a period of active growth, the outcome is the development of the "Adenoid Facies." Such patients characteristically manifest a vertically long lower third facial height, narrow alar bases, lip incompetence, a long and narrow maxillary arch, and a greater than normal mandibular plane angle.
In 1872, Tomes described the "adenoid face" and the concept that facial form can be influenced by enlarged adenoids became accepted as hypothesis. Tome's view was supported by many leading orthodontists including Todd and Broadbent  and Balyeat and Bowen. 
Angle  included airway obstruction as an important etiological factor in malocclusion. Moss  in developing the functional matrix theory presented a logical rationale for the findings seen in nasally obstructed patients. His view was that bone responds to the influence of function, of the adjoining soft tissue, explained the narrow palate and long face seen in mouth breathers.
Mouth breathing due to obstructive adenoids and tonsils has deleterious effects on the craniofacial morphology especially on dentition and dental arches. Our study ultrasonographically evaluated the effectiveness of the circumoral muscle exercises in the developing dentofacial morphology with mouth breathing habit in adenotonsillectomized children.
Numerous studies have been conducted to find the effect of chronic absence of active nasal respiration. Certain animal research studies have indicated that factors other than oral respiration may induce altered skeletal growth. Moss  found that bipedal rats (created by amputating a pair of legs) developed changes in both habitual body and head positions as well as in the cranial morphologic characteristics.
Reisenfeld  observed that bipedal rats developed the greatest cranial curvature forward movement of the foramen magnum, a narrower skull, and dolicocephalization. Tomer and Harvold  and Vagervik  et al . showed that there was an increase in lower face height and steepness of the mandibular plane which followed the establishment of oral respiration in primates. Harvold  et al , states that "Nasal obstructions present the trigger factor, but it is the deviant muscle recruitment which causes maldevelopment".
According to Paul and Nanda,  there is much evidence that mouth breathing produces deformities of the jaws, inadequate position or shape of the alveolar process and malocclusion.
Linder-Aronson  demonstrated varying degrees of recovery from steep mandibular plane angle, narrow maxillary arches, and retroclined maxillary and mandibular incisors during the 5 years after adenoidectomy and a change from mouth to nose breathing ( P <0.01).
Although alterations in the skeletal pattern of mouth breathers were not observed, alterations in teeth position,  constriction of the maxillary arch and proclined incisor were recorded, as reported by Johnson  and Breuer. 
Ricketts  stated that dental eruption is guided by the form and position of the basal bone, which is shaped by the musculature organs i.e. tongue and lips.
O'ryan et al ,  in their review stated that although several articles suggested a direct cause and effect relationship between nasal airway obstruction and altered dentofacial morphology, further well-controlled studies designed to quantitate the relative amount of oral versus nasal respiration were necessary before airway obstruction could be implicated as a significant etiologic factor in the development of any specific dentofacial deformity.
Schlenker et al ,  has stressed the relationship of oral respiration in orthodontic patients.
Shanker et al ,  has conducted a study on the dentofacial morphology and upper respiratory function in 8- to 10-year-old children. All these studies highlight the effects of mouth breathing.
Rogers  was among the first to recommend the use of muscles to correct malocclusion. The essence of myofunctional therapy, as well as most functional appliances was to use muscle activity as the primary source of force for the resolution of malocclusion.
Animal model experiments of Harvold  and McNamara and their co-workers  demonstrated the significant potential of myofunctional exercises.
The provocative clinical result shown by Frankel  and his disciples point up the great potential of the appliances, which alter orofacial muscle balance.
Owman Moll and Beng Ingervall  in their study showed that active lip training increase lip size and improved lip function in patients with incompetent lips. Upper and lower lip length was increased and the interlabial gap was reduced.
Taner-Sarisoy  highlighted the importance of functional therapy at early age for favorable changes in profile and lip seal. It was suggested that lip seal therapy and exercises with vestibular or oral screen produces alteration in the functional environment, which induce, a chain of adaptive changes in the network of postural system of the orofacial complex.
The respiration transfer caused by nasal air obstruction may determine the open mouth posture habit, even after nasal disobstruction. ,
Imaging with ultrasound is widely used for the prenatal measurement of structures such as fetal eyes  and for the early detection of malformation such as cyclopia.,, Cleft lip imaging of muscle dimension has been shown to be possible by Alexander and Vernon. Ikai and Fukunage  and Dons et al  have used ultrasound to measure the changes in muscle size as a result of weightlifting. Cady, Gadener, and Edwards  have used ultrasound to detect diseased muscle.
Comparing the ultrasound images of the lips during relaxation and contraction under standard condition was considered to be a more useful method for obtaining baseline information about changes in the musculature of the lips than describing and quantifying changes during actual movement from one state to the other.
Killiards et al ,  studied the masseter muscle thickness using an ultrasound and found it to be reliable and accurate method which could relate the variation in the thickness of the muscle to variation in the facial morphology in different individuals.
Vinkka-Puhakka et al ,  ultrasonographically imaged the circum oral musculature and concluded that it was made up of only a part of the total thickness of the lips and varied among individuals in shape, transonicity (clearness), and thickness.
Prabhu and Munshi  have found definite changes in the thickness of the muscles in relaxed and contracted states in various malocclusion states.
Anupam and Sobha  highlighted the imaging of circumoral musculature using ultrasound to evaluate the effectiveness of muscle exercises in adenotonsillectomized children. Definite changes in muscle thickness were noted in subjects who were given muscle exercises.
Due to the favorable study results by Killiards et al ,  Prabhu and Munshi  and Kumar and Kuriakose,  the present study was taken up to evaluate and correlate the changes in the thickness of the circumoral musculature in adenotonsillectomized children who were given muscle exercises. For our study, a Volvson 730 PRO with superficial probe SP of 6-12 mHz was used which gives best possible resolution for the superficial structure.
Ultrasonograhic evaluations performed before and after the circumoral muscle exercises were compared between the experimental and control groups and the results indicated a significant increase in the muscle thickness and overall improvement in achieving good oral seal only in the experimental group. These results strongly correlate with the similar study conducted by Kumar and Kuriakose. 
Linder-Aronson et al ,  found that in girls, after adenoidectomy, mandibular growth proceeded in a more horizontal direction ( P <0.01) than in matched controls. Also, after adenoidectomy, they found more individual variation in mandibular growth direction (MGD) than in the controls ( P <0.05) for both boys and girls, indicating that, after removal of adverse environmental factors, the degree of recovery varies.
Rogers  has found that persistent open bite due to mouth breathing caused by the lack of tone of facial muscles, particularly the orbicularis oris, has improved after proper systemic exercises.
So, this fact is very relevant in our study, which also shows that there was increase in the muscle thickness after circum oral muscle exercises within the prescribed period, thus, highlighting the importance of incorporation of such exercises as part of treatment after adenoidectomy.
Based on the results of this study, we recommend the re-establishment of the breathing pattern with nasal predominance as soon as any type of alteration in respiratory function is diagnosed to prevent any dentofacial maldevelopment.
Co-operation with otolaryngologists is highly recommended who treat children with adenotonsil enlargement, they should make it mandatory to refer the patient to the pediatric dentists as soon as the patients report back to them after surgical healing period, as pediatric dentists play an important role in the diagnosis and co-management of patients with mouth breathing. Besides the surgical treatment approach itself, the treatment sometimes, is always myofunctional therapy, the earlier it is initiated, the more effective, simple and non-restraining.
This would help the pediatric dentists to start the lip seal therapy and exercises with oral screen as early as possible to restore the normal nasal breathing and aid in the normal dentofacial development, rather than to wait until 90% of the deformity has established to start orthodontic treatment, before instituting treatment which is not consistent with our preventive attitude.
| Conclusions|| |
Based on the results of this study we conclude that
- Significant changes in the muscle thickness were noticed in the experimental group after 6 months of prescribed lipseal therapy and exercises with oral screen.
- The oral screen has been a suitable appliance for lip training. The screen stretches the lip musculature, providing a force which retroclines proclined incisors, and lips are strengthened simultaneously.
- Mouth breathers, who had adenotonsil enlargements did not become nasal breathers after surgery, only active circum oral exercises made them nasal breathers.
- Early incorporation of circumoral exercises should be included as a part of the treatment after the surgery in mouth breathers, who were adenotonsillectomized.
| References|| |
|1.||Vinkka-Puhakka H, Kean MR, Heap SW. Ultrasonographic investigation of circum-oral musculature. J Anat 1989;166:121-33. [PUBMED] [FULLTEXT]|
|2.||Moss ML. The primary role of functional matrices in facial growth. Am J Orthod 1969;55:566-77. |
|3.||Cooper BC. Nasorespiratory function and orofacial development. Otorinolaryngol Clin N Am 1989;22:413-41. |
|4.||Dunn GF, Green LJ, Cunat JJ. Relationship between variation of mandibular morphology and variation of nasopharyngeal airway size in monozygotic twins. Angle Orthod 1973;43:129-35. [PUBMED] [FULLTEXT]|
|5.||Koski K, Lahdemaki P. Adaptations of the mandible in children with adenoids. Am J Orthod 1975;68:660-5. |
|6.||Linder-Aronson S. Adenoids: Their effects on mode of breathing and nasal airflow and their relationship to characteristics of the facial skeleton and dentition. Acta Otolaryngol Suppl 1973;35:283-302. |
|7.||Hulcrantz E, Larson M, Hellquist R, Ahlquist-Astad J, Svanholm H, Jakobson OP. The influence of tonsillar obstruction and tonsillectomy on facial growth and dental arch morphology. Int J Pediatr Otorhinolaryngol 1991;22:125-34. |
|8.||Schendel SA, Eisenfeld J, Bell WH, Epker NB, Mishelevich DJ. The long face syndrome:Vertical maxillary excess. Am J Orthod 1976;70:398-408 |
|9.||Principato JJ. Upper airway obstruction and craniofacial morphplogy. Otolaryngol Head Neck Surg 1991;104:881-90. [PUBMED] |
|10.||Rogers AP. Exercises for the development of muscles of face with view to increasing their functional activity. Dental Cosmos LX 1918;59:857-76. |
|11.||Frankel R. Lipseal training in the treatment of skeletal open bite. Eur J Othodontics 1980;2:219-228. |
|12.||Ikai M, Fukunaga T. A study on training effect on strength per unit cross-sectional area of muscle by means of ultrasonic measurement. Internationale Zeitschrift fur angewandte physiologie 1970;28:173-80. |
|13.||Dons B, Bollerup K, Bonde-Petersen F, Hancke S. The effect of weight-lifting exercise related to muscle fiber composition and muscle cross sectional area in humans. Eur J Appl Physiol 1979;40:95-106. |
|14.||Prabhu NT, Munshi AK. Ultrasonographic observation of the circumoral musculature: An in-vivo study. J Clin Pediatr Dent 1995;19:195-203. [PUBMED] |
|15.||Harvold EP, Tomer BS, Vargervik K, Chierici G. Primate experiments on oral respiration. Am J Orthod Dentofac Orthop 1981;79:359-72. |
|16.||Bresolin D, Shapiro GG, Shapiro PA, Dassel SW, Furukama CT, Pierson WE, et al. Facial characteristics of children who breathe through the mouth. Pediatric 1984;73:622-5. |
|17.||Lowe AA, Takada K. Association between anterior temporal, masseter an orbicularis oris muscle activity and craniofacial morphology in children. Am J Orthod 1984;86:319. [PUBMED] |
|18.||Kerr JS, McWilliam JS, Linder-Aronson S. Mandibular form and position related to change mode of breathing, five years longitudinal study. Angle Orthod 1987;59:91. |
|19.||Gross AM, Kallum GD, Hale ST, Messer SC, Benson BA, Sisakun SL, et al. Myofunctional and dentofacial relationship in second grade children. Angle Orthod 1989;60:247. |
|20.||Emslie, RD, Massler M, Zwemer JD. Mouth breathing: I etiology and effects (a review). J Am Dent Assoc 1952;44:506. |
|21.||Breuer J. El paciente respirador bucal. Revista de la Association Odontologica Argentina 1989;77:102. |
|22.||Todd TW, Cohen MD, Broadbent B. The role of allergy in the etiology of orthodontic deformity. J Allergy 1939;10:246-9. |
|23.||Balyeat RM, Bowen R. Facial and dental deformities due to perennial nasal allergy in childhood. Int J Orthodont 1934;20:445-9. |
|24.||Angle EH. Treatment of malocclusion of the teeth. 4 th ed. Philadelphia: SS white Dental Manufacturing Co; 1907. |
|25.||Moss ML. The functional matrix, functional cranial components in vistas in orthodontics. In: Kraus BS, Reidel R, editors. Philadelphia: Lea and Febiger; 1962. p. 85-98. |
|26.||Moss ML. Roataion of the otic capsule in bipedal rats. Am J Phs Antropol 1961;19:301-7. |
|27.||Riesenfield A. Head balance and brachycephalization. Momo 1969;20:81-90. |
|28.||Tomer BS, Hrvold EP. Primate experiments on madibular growth direction. Am J Orthod 1982;82:114-9. |
|29.||Vargervik K, Miller AJ, Chierici G, Harvold E, Tomer BS. Tomer. Morphologic response to changes in neuromuscular patterns experimentally induced by altered modes of respiration. Am J Orthod Dentofac Orthop 1984;85:115-24. |
|30.||Paul JL, Nanda RS. Effects of mouth breathing on dental occlusion. Angle Orthod 1973;43:201-6. |
|31.||Linder-Aronson S. Effcets of adenoidectomy on the deviation and facial skeleton over a period of five years. In: Cooko JT, editor. Transactions of the third international congress. London: Crosby Lockwood Staples; 1975. p. 85-100. |
|32.||Johnason LR. Habits and their relation to malocclusion. J Am Dent Assoc 1943;30:848. |
|33.||Ricketts RM. Respiratory obstruction syndrome. Am J Orthod 1968;54:495. |
|34.||O'Ryan FS, Gallager DM, LaBanc JP, Epker BN. The relationship between nasorespiratory function and dentofacial morphology: A review. Am J Orthod 1982;82:403-10. |
|35.||Schlenker WL, Jennings BD, Jeiroudi MT, Caruso JM. The effects of chronic absence of active nasal respiration on the growth of skull: A pilot study. Am J Orthod Dentofac Orthop 2000;117:706-13. |
|36.||Shanker S, Vig KW, Beck FM, Allgair E Jr, Vig PS. Dentofacial morphology and upper respiratory function in 8- 10 year old children. Clin Orthod Res 1999;2:19-26. |
|37.||Harvold EP, Vagervik K. morphogenic response to activator treatment. Am J Orthod 1971;60:478. |
|38.||McNamara JA, Carlson DS, Yellich GM, Hendricksen RP. Musculoskeletal adaptation following orthognathic surgery; Muscle adaptation in the craniofacial region. Ann Arbor: University of Michigan; 1978. |
|39.||Frankel,R. Funktionsorthopadie und der Mundvorhof als apparative Basis. Berlin: Verlag Volk und Gesundheit; 1967. |
|40.||Owman-Moll P, Ingervall B. Effect of oral screen treatment on dentition, lip morphology, and function in children with incompetent lips. Am J Orthod 1984;85:37-46. |
|41.||Taner-Sarivoy L. Early treatment of a severe class II division I malocclusion. J Clin Pediatr Dent 1998;23:23-6. |
|42.||Spalding PM, Vig PS. respiration characteristics in subjects diagnosed as having nasal obstruction. J Oral Maxillofac Surg 1988;46:189. |
|43.||Jeanty P, Dramaix-Wilmet M, Van Gansbeke D, Van Regemorter N, Rodesch F. Fetal ocular biometry by ultrasound. Radilogy 1982;83:115-24. |
|44.||Elejalde MM, De Hamilton PR, Elejalde BR. Viasualization of the fetal face by ultrasound. J Craniofac Genet Dev Biol 1984;4:251-7. |
|45.||Elejalde BR, Elejalde MM, De Hamilton PR, Christeenson R, Broekhuizen F. Prenatal dignosis of cyclopia. Am J Med Genetics 1983;14:15-9. |
|46.||Le-Marec B, Duval JM, Milton J, Grall JJ, Roussey M, Chatel M, et al. The use of echography in prenatal diagnosis in problems of familial cyclopia. J Genet Hum 1980;28:217-23. |
|47.||Alexander R, Vernon A. The dimensions of knee and ankle muscles and the forces they exert. J Hum Movements Studies 1995;1:115-23. |
|48.||Cady EB, Gardener JE, Edwards RH. Utrasonic tissue characterization of skeletal muscle. Eur J Clin Investig 1983;13:469-73. |
|49.||Killiards S, Kalebo P. Masseter muscle thickness measured by ultrasonography and its relation to facial morphology. J Dent Res 1991;70:1262-5. |
|50.||Kumar TVA, Kuriakose S. Ultrasonographic evaluation of effectiveness of circumoral muscle exercises in adenotonsillectomized children. J Clin Pediatr Dent 2004;29:49-56 |
|51.||Linder-Aronson S, Woodside DG, Lundstrom A. Mandibular growth factor direction following adenoidectomy. Am J Orthod Dentofac Orthop 1986;89:273-84. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]