The normalization of functional disturbances is one of the main objectives that need to be achieved during early orthodontic treatment. There is a close relationship between anterior open bite in young patients and abnormal habits that are some of the main etiological factors of malocclusion.
The most common habits are thumb-sucking, lip/nail biting, tongue thrusting, and mouth breathing mode. Normally, all of these habits could cause interferences with the circumoral musculature and tongue pressure balance, and as a consequence, they develop unaltered maxillary and mandibular arch forms. Of course, the duration, frequency, and intensity of these habits play an important role, not only in the diagnosis and treatment plan but also during the whole retention phase.
Since there isn’t only one reason for digital sucking or the prolonged use of pacifiers, there isn’t only one treatment for all of them. It is important to control the habit after 2 years of age. In some patients, the help of a psychologist is valuable. Digital sucking is responsible for causing significant changes in the maxilla and in the mandible during the growth period.
In general, the maxilla becomes narrow and V shaped, the mandible tends to be retrognathic, and, as a consequence, a significant open bite is developed with proclined upper incisors and retruded lower incisors.
Due to the excessive proclination of the upper incisors, lips become incompetent and the tongue is placed between the upper and lower incisors during the swallowing process, worsening it. Also, there is a significant link between the respiration mode, the direction of the facial growth, and the development of the malocclusions (posterior cross bite and anterior open bite), due to abnormal contraction of the cheek muscles.
Hypertrophic lymphoid tissues and nasal obstruction in combination with large adenoids and tonsils are the most common cause of nasal obstruction and mouth breathing as they push the tongue forward due to pain and decrease in the amount of posterior space for the tongue.
This atypical swallowing pattern and the anterior posture of the tongue at rest prevent the eruption of the incisors and increase the anterior open bite with lower lip interposition every time the patient swallows.
In general, these young patients are sent to the speech therapist in order to improve the pronunciation of certain words, but it is important to remember that the anterior open bite is the consequence, not the cause. Also, orofacial and speech dysfunction could be com- bined with problems at the TMJ that could worsen in the future.
In addition to TMJ problems, episodes of sleep apnea could be added. The child could stop breathing several times during the night (20–40 times per hour of sleep). As a consequence, he or she would feel daytime sleepiness, headaches, fatigue, obesity, changes in personality, lack of attention at school in the morning, etc. Since sleep apnea is a progressive disorder, the consulta- tion with the specialist is very important from the first day in order to perform a multi- and interdisciplinary treatment plan and avoid relapse (Pascually et al.).
It is important to remember that sleepwalking in young children and enuresis are commonly related to open bite problems. The real question is who, when, why, and how to treat.
The higher the percentage of environmental factors in relation to the genetic ones, the better the prognosis. Among the deleterious habits, the prolonged use of pacifiers, mouth breathing, or thumb-sucking are determinants. In some patients, the help of a psychologist is fundamental to control the habits.
Unfortunately, there isn’t only one type of appliance to treat all these patients. The appliance selection has to be related to the etiology, age of the patient, seriousness of the problem, etc. The orthodontist is responsible for the appropriate selection.
The decision of whether to use a removable, fixed appliance or a combination of both is related to the etiology and the skeletal maturity in order to maximize the effectiveness of the orthodontic treatment.
The normalization of the vertical dimension is extremely challenging for the orthodontist to control, especially in high-angle patients with mouth breathing.
If problems leading to an open bite could be identified and treated early, it might be possible to minimize or even eliminate an undesirable pattern of growth.
According to the structures affected, anterior open bite can be divided into three main categories: dental, dentoalveolar, and skeletal.
Dental and dentoalveolar open bites develop as a result of prolonged mechanical blockage of the normal vertical development of anterior teeth and alveolar process (Torres et al. 2012).
The skeletal form, in turn, is characterized by a significant vertical skeletal discrepancy, with features such as counter- clockwise rotation of the palatine process, increased lower anterior facial height and gonial angle, short mandibular ramus, and increased posterior dentoalveolar height in both mandible and maxilla.
3.1 Diagnosis
Medical and dental analysis
Evaluation of growth Functional analysis
Patients’ chief complaint
Photographic and radiologic evaluation
Vertical facial pattern
Unfavorable growth pattern
The treatment goals should include the removal of the etiological and environmental factors to permit the normalization of the anterior growth development.
Until now, no consensus has been reached to determine the best time to initiate the orthopedic/orthodontic treatment. Nonetheless, it is totally accepted that the earlier the correction of the open bite begins, the better the results will be. Also, early treatment helps avoid relapse.
Myofunctional therapy is the best option to normalize mouth breathing. Control and reduction of the extrusion of the molars are fundamental to allow a counterclockwise rotation of the mandible to maintain the results.
Failure to control bad habits may be the most important reason of relapse. The role of the otolaryngologist to improve and normalize nasal breathing during the diagnosis process and speech pathology is of prime importance.
In general, anterior open bite in temporary or early mixed dentition is associated with digital sucking habit and tongue anterior interposition. Its correction is very important since otherwise the problem could worsen and turn into a skeletal alteration.
The size and length of the lips are also important to maintain a proper lip seal during day and night. Also, it is necessary to normalize the position and function of the tongue. Normally, children who breathe through their mouth have a narrow maxillary arch, protrusive incisors, Class II occlusion, convex facial profile, bags under the eyes, an open mouth posture, and narrow nostrils. The importance of the multidisciplinary treatment cannot be denied. Treatment strategies are in close relationship with etiology, facial biotype, age of the patient, and clinical experiences.
The management of the tongue thrust and mouth breath- ing involves the interception of the habit. First of all, the doc- tor has to determine that the patient can use his/her nose to breathe normally. It is important to remember that mouth breathing is abnormal and can affect the whole stomatognathic system, body posture, etc., and not only the position of the teeth. As soon as this problem is corrected, fewer consequences appear.
Different appliances could be used according to the age of the patient and his/her medical history, in order to establish a new neuromuscular pattern.
According to the etiology and the importance of the prob- lem, removable, fixed, or a combination of both types of appliances can be used. The orthodontist has the final decision.
The following examples will describe each option in detail. This 6-year, 8-month-old patient is sent to the office by her family dentist in search of a second opinion regarding her anterior open bite.
An adenoidectomy was performed 4 months earlier. Nonetheless, mouth breathing and tongue thrusting contin- ued. It was difficult for her to close and maintain the lips sealed. She used a pacifier until 4 years of age (Fig. 3.1a, b).
Her profile was convex, and the nasolabial angle was reduced. Even though she was only 6 years and 8 months of age, she had a double chin. Hyperactivity of the musculature of the lips in combina- tion with tongue thrust with abnormal tongue posture during speech was observed during the clinical examination.
The front photograph showed a significant open bite in the anterior region in combination with a midline deviation. Only the central upper and lower incisors were erupting at that time (Fig. 3.2a, b).
No posterior cross bite was present. All day and night, the tongue was placed between the upper and lower incisors which were why they could not erupt normally. Due to the presence of large cavities, some stainless steel crowns were placed on the temporary molars (Fig. 3.3a, b).
The treatment objective (Phase I) was to normalize over- bite and overjet, maintain Class I molar, control tongue thrust, improve the activity of the lips, and enhance her profile.
To achieve this objective, the use of a functional appliance is decided on. Of all the possible choices, a prefabricated functional appliance also known as Trainer System TM (Myofunctional Research Co. Australia) was chosen. It is fabricated with a special type of polyurethane and helps the correction and normalization of the muscular dysfunction.
The appliance is especially designed to stimulate anterior and lateral muscles and help to achieve normal nasal breathing. Since the material is soft, no major problems of adaptation are present (Fig. 3.4a, b).
It is recommendable that at the beginning, this appliance be used few hours during the day (2–3 h) and then all night (Fig. 3.5a, b).
After 9 months, a significant improvement of the maxillomandibular relationship was clearly observed. The anterior open bite was totally closed, and midlines were almost normalized (Fig. 3.6a, b).
The transverse development observed in some patients could be due to the buccal shields of the trainer that stimulates the lateral muscles using the same principles that Frankel regulator does.
The treatment goals were totally achieved without the use of any other appliance.
Upon analyzing the front and lateral photographs, a significant improvement in the lower third of the face was achieved. The patient could close her lips without tension, and the tongue was located in its right position not only at rest but in active position too (Fig. 3.7a, b).
These were the results 18 months later. Class I canine was achieved and Class I molar was maintained. Overjet and overbite were normalized and midlines were normal. Oral hygiene was fairly good (Fig. 3.8a, b).
The profile and smile lateral photographs confirmed the results. The lips were relaxed and the double chin was absent. A 6-month follow-up was highly recommended (Fig. 3.9a, b).
It is advisable that open bites be treated as early as possi- ble and in this way reinstate normal oral and breathing func- tions to reduce the possibility of relapse. The type of trainer (T4K) is a valid alternative to treat these open bite patients at an early age. It also helps to improve dental arch development during the early and late mixed dentition, and most importantly, this appliance helps normalize bad habits.
Also, other types of functional appliances can be used according to the orthodontist’s preferences. As always, correct diagnosis is more important than the type of the appliance used.
The comparison between the pre- and posttreatment front dental photographs showed evidence of the normalization of the anterior open bite and the parallelism between the occlusal and gingival planes.
No brackets were required to achieve the expected results. Ideally an overcorrection of the overjet and overbite is highly recommended (Fig. 3.10a, b).
A 6-month control was recommended until all the second molars erupted. Upon analyzing the lower third of the face and the nasola- bial angle, a significant improvement was confirmed. Moreover, the lips were more relaxed and the double chin was normalized (Fig. 3.11a, b).
Further studies should be conducted to analyze if the use of this treatment protocol would have a skeletal effect in patients with anterior open bite.
In general, patients with anterior open bite have a high-angle facial pattern and also have discrepancies in the anteroposterior and transverse dimensions. The retention protocol has to include a strict control of the position and function of the tongue.
This 9-year, 2-month-old patient was sent by her family dentist due to her significant midline deviation and slight Class III tendency.
Her profile was straight with a normal nasolabial angle. She snored loudly at night, very often (Fig. 3.12a, b).
The dental front photograph clearly showed the anterior open bite and the important deviation of the midlines (3 mm). She had a V-shaped maxilla (Fig. 3.13a, b).
The right second temporary molars had a Class III tendency, and there was a significant lateral cross bite on the left side that was maintained in central relation.
No TMJ symptoms were present until then, but she preferred to eat only soft food. He dental hygiene was fairly good and no cavities were present (Fig. 3.14a, b).
The panoramic Rx confirmed that no agenesias or supernumerary teeth were present, and the lateral radiograph showed normal development according to her age. The anterior open bite was clearly visible (Fig. 3.15a, b).
The treatment objectives were:
1. Align and level the arches.
2. Normalize transverse dimension.
3. Normalize overjet and overbite.
4. Achieve Class I molar and canine.
5. Control tongue thrust.
6. Long-term stability.
To achieve these objectives, the following treatment plan was designed:
Phase I
1. Rapid maxillary expansion to normalize the transverse problems
2. Speech therapy treatment to control tongue thrust
Phase II
If necessary, esthetic brackets, 0.22″ slot in order to nor- malize dental positions, will be used.
To correct the transverse deficiency, a modified hyrax appliance was suggested. The protocol of activation was twice a day. The lateral arms were bonded with composite to the temporary molars to improve stability. After 2 weeks, the inter-incisal diastema between the central incisors confirmed that the central suture was open (Fig. 3.16a, b).
The correction of maxillary constriction is very often a target for treatment in open bite patients (McNamara and Brudon 1993).
As usual, 1 month later, the diastema closed on its own, and a monthly follow-up was suggested. The anterior open bite was totally normalized with the help of a speech thera- pist. Midlines were almost corrected.
In these cases, it is highly recommendable that RME appliance be maintained in place a minimum of 6 months to prevent relapse (Fig. 3.17a, b).
At the end of the first phase of treatment, all the objectives were achieved. The overjet and overbite were normalized as well as the position of the first molars. A removable retainer used during the night was recommended to maintain the correction of the transverse dimension, until the second molars and upper canines erupted (Fig. 3.18a, b).
The lateral and smile posttreatment photographs confirmed the results that were achieved. The lips closed smoothly with- out tension and the nasolabial angle was normal (Fig. 3.19a, b). Twenty months later, the patient returned to the office seeking improvement of the position of the canines. To achieve
these results, esthetic bracket slot 0.022″ were bonded in con- junction with a 0.016″ SS wire (Fig. 3.20a, b)
A nickel-titanium open-coil spring, slightly activated, was placed on the left side to improve the position of the first upper left bicuspid (Fig. 3.21a, b).
Seven months later, upper esthetic brackets were removed and the tongue thrusting habit was totally corrected (Fig. 3.22a, b).
Front photographs at the end of the second phase treat- ment. The face was symmetrical with balanced proportions and normal exposure of the maxillary teeth. The smile and tongue positions were totally normalized (Fig. 3.23a, b).
The lateral photographs confirmed the results. The patient was able to close her lips gently in concordance with a nice and pleasant profile and a passive lip seal (Fig. 3.24a, b).
The comparison pre- and posttreatment dental front pho- tographs confirmed that the treatment objectives were totally achieved. Dental midlines were corrected and overjet and overbite were normalized. The gingival and occlusal plane were parallel and the oral hygiene was fairly good (Fig. 3.25a, b).
The importance of the normalization of the functional problems is clearly demonstrated when the following patient is analyzed.
She was 7 years, 3 months of age and was sent to the office by her pediatric doctor due to her loud night snoring that disturbed not only her sister but also her parents’ sleep. She had a convex profile, difficulty to achieve lips clo- sure, and a double chin that are typical in all mouth breathers in conjunction with a larger lower third face and the presence of circles under their eyes. Frequently, she had colds with fever and was medicated with corticoids and antibiotics.
It is important to remember that abnormal tongue posture is associated with enlarged adenoids and tonsils in addition to sucking habits and tongue thrust (Fig. 3.26a, b).
The front dental photographs clearly confirmed the ante- rior position of the tongue at rest and an important open bite of 7 mm at the incisor region (Fig. 3.27a, b). A significant cross bite was present in the right side.
The lateral views showed Class II molar on the right side and Class I molar on the left side. The temporary right canine, first and second molars, as well as the permanent first molar were in cross bite occlusion. The oral hygiene was good and no cavities were observed (Fig. 3.28a, b).
The panoramic radiograph confirmed that all the permanent teeth were present in different stages of development in accordance to her age. The open bite was confirmed on the lateral radiograph, and it was clearly visible that the respira- tory airway was obstructed (Fig. 3.29a, b).
After the consultation with the pediatrician, the following treatment plan was decided:
1. Normalize the mouth breathing pattern.
2. Improve the position of the tongue at rest.
3. Normalize the position of the right canine and molars.
4. Achieve normal overjet and overbite.
5. Long-term stability.
In order to correct the transverse problem, a fixed bonded rapid maxillary expander was suggested. The design included bands on the right and left temporary second molars to pro- tect the permanent first molars. The activation was a quarter twice a day for 2 weeks (Fig. 3.30a, b).
At the same time, she was sent to the speech therapist to normalize the position of the tongue and in this way help close the anterior open bite. After 2 weeks, the expansion was completed. It is highly recommendable that the expander be maintained in place for a minimum of 6 months to have better control over relapse (Fig. 3.31a, b).
The speech therapist had to continue working with the patient until the overjet and overbite were normalized.
A follow-up 2 months later confirmed the improvement achieved. The inter-incisal diastema was closing normally, and the position of the central incisors was normalized (Fig. 3.32a, b).
Different types of RME can be used, but it is preferable to use those without acrylic plates not only on the palatal tis- sues but also on the occlusal surfaces of the molars. The protocol of activation is determined by the orthodon- tist, but twice a day is usually sufficient. The patient was gone for 2 years and she returned without the RME. The anterior occlusion was edge to edge, and a slight open bite was still present. Cuspids and bicuspids had almost erupted (Fig. 3.33a, b).
The lateral photographs showed slight lateral open bite in the lateral incisor and canine region, and tongue interposi- tion was still present in this area (Fig. 3.34a, b).
After a long conversation with the parents and the patient, they accepted a second phase of treatment with fixed appli- ances in order to improve her dental occlusion and prevent any type of relapse of the anterior open bite (Fig. 3.35a, b).
New panoramic and lateral radiographs showed normal eruption of the cuspids and bicuspids with no evidence of root resorption.
According to Ricketts, she had a dolichofacial pat- tern with some protrusive incisors and a moderately increased lower anterior facial height and gonial angle (Fig. 3.36a, b).
Esthetic preprogrammed 0.022″ slot brackets were bonded on the upper and lower teeth with SS 0.016″ wires to align and level the arches. No extraction of bicuspids was planned at that time.
Midlines are almost coincident (Fig. 3.37a, b). No brackets were bonded on the second lower temporary molars. However, manual stripping was performed on the mesial side in order to achieve Class I canine on the left and right side (Fig. 3.38a, b).
The upper and lower arches showed great improvement. The lower second right and left temporary molars were still in place (Fig. 3.39a, b). The dentoalveolar changes were sig- nificant with a greater improvement in the incisor position and inclination. The vertical control was very important in order to avoid an increase of the lower facial height, during the growth period.
These were the results 2 months after debonding. Midlines were coincident. Overbite and overjet were almost normal and the oral hygiene was fairly good (Fig. 3.40a, b).
Right and left Class I canine and molar were obtained with good interdigitation in the bicuspids area. The gingival line and the occlusal plane were parallel (Fig. 3.41a, b).
A fixed retention wire was bonded on the upper and lower arches to maintain the position of the incisors. Longterm retention as well as a removable appliance were rec- ommended to control the function of the tongue (Fig. 3.42a, b).
The final photographs after the orthodontic treatment showed a significant improvement in the lower third of the face. She could close the lips without tension and there wasn’t a gingival smile. The dental midline was coincident with the facial one (Fig. 3.43a, b).
The profile photographs clearly showed a muscle equilibrium. The profile was still straight and the nasolabial angle was normal (Fig. 3.44a, b).
The patient returned 3 years later for follow-up of her retention wires. Her smile was better than ever and the oral muscles were completely relaxed. In the end, she had a symmetrical face with balanced proportions (Fig. 3.45a, b).
The nasolabial angle was more open even though no extractions were performed in the upper arch nor in the mandible. A nice and broad smile was achieved (Fig. 3.46a, b).
When analyzing the front photographs 3 years later, a slight relapse in the anterior region was observed. With this in mind, it was advisable to finish the case with a bigger overbite in order to avoid relapse (Fig. 3.47a, b).
Class I canine and molar were maintained. A 6-month follow-up was highly advisable in order to maintain or improve the results that were achieved (Fig. 3.48a, b).
The observation of the pre- and postfrontal dental photo- graphs showed that the treatment objectives were achieved. The gingival line and the occlusal plane were parallel, and the hygiene was very good.
This confirmed that to obtain an efficient therapeutic result, correct diagnosis and treatment timing are very impor- tant (Fig. 3.49a, b).
The comparison of the pre- and postfrontal photographs clearly demonstrated how the soft tissues were improved as a consequence of the correction of the bad habits. Now, the patient closes her lips normally.
The importance of tongue posture and tongue function cannot be denied (Fig. 3.50a, b).
The results were similar from the lateral side. She had a straight profile and closed her mouth in a normal way with reduction of the lip protrusion and decreased mentalis strain.
The nasolabial angle was less protrusive even though no bicuspid extractions were performed. There was a significant improvement in vertical skeletal and dentoalveolar relationships due to the elimination of the tongue thrust and mouth breathing. This patient confirms the theory that early treatment in conjunction with the normalization of the functional habits prevents asymmetric alveolar bone growth that affects the permanent dentition (Fig. 3.51a, b).
The present clinical case clearly demonstrates that if proper diagnosis is obtained and orthodontic biomechanics are well designed, stable results can be achieved in a patient with severe anterior open bite. The post-retention stability of open bite treatment is a controversial topic in orthodontics. Relapse is unpredictable.
The etiology could be tongue thrust because of its size or posture, respiratory problems, sucking habits, condylar resorption, direction of growth, etc.
Habit elimination is mandatory to prevent open bite relapse. How can relapse be prevented? Better diagnosis and an individualized treatment and retention plan.
Conclusions
Ideally, open bite patients should be treated as early as possible. Unfortunately, there is no specific bracket or arch wire to help the normalization of the position of the tongue. These three patients were treated with different appli- ances since the etiologic reasons at the beginning were different: the first one used a pacifier until 4 years of age and had an adenoidectomy, the second one had a persis- tent tongue thrusting habit until 9 years of age, and the third one was a combination of both.
The young patient has to understand that the appliance will help him or her to control the habit. The positive role of the parents to accompany the process was essential. From a clinical point of view, early treatment with removable or fixed appliances is more effective and reduces the length of treatment in the permanent dentition with less surgical procedures and more stability.
It is well known that environmental and neuromuscu- lar influences may alter the position of the teeth and the direction of the maxilla and mandibular growth. It is important to determine the presence or absence of naso- or oropharyngeal obstructions that can alter the position of the tongue and the mandibular posture. Dentofacial changes associated with mouth breathing and its relation with some types of malocclusions that involve the presence of long face syndrome are well rec- ognized (Linder-Aronson and Woodside 2000).
The role of the otolaryngologist and speech therapist is unquestionable in the diagnosis and treatment procedures. There is strong evidence that the earlier the open bite malocclusion is corrected, the better the prognosis will be, and of course, habit elimination is mandatory to pre- vent open bite relapse.
Ideally, the treatment has to begin when the children are 4–6 years old as most of the functional and dentofacial problems begin at this age, and also there is a reduction in the risk of trauma of the upper front teeth. The prevention of the apnea problems is more impor- tant than the correction of the snoring. Remember that snoring in children in conjunction with poor concentra- tion at school and behavioral problems are the most typi- cal signs of sleep apnea episodes in children.
Relapse is unpredictable since the etiology could be multifactorial (condylar resorption, respiratory problems, continuous tongue thrust, direction of growth, habits, etc.). It is well known that the stability after retention of the open bite treatment is a controversial issue for the orthodontists.
The effectiveness and efficiency of an early orthope- dic/orthodontic treatment, based on a correct, individual- ized, and exhaustive diagnosis, are undeniable. Long-term control is fundamental to confirm the achieved results (Huang 2002). The normalization of the anterior open bite is impera- tive taking into account the health problems that can occur later on.
Unfortunately, there isn’t a specific bracket or wire to treat all these patients nor to help in the normalization of the tongue position. The parents and the young patients have to be aware that the earlier the correction of the dysfunctional habits begins, the better and more effective the results will be. A complete multi- and interdisciplinary early treatment plan is the key to correct the anterior open bite and the func- tional disturbances associated with it.
The most common habits are thumb-sucking, lip/nail biting, tongue thrusting, and mouth breathing mode. Normally, all of these habits could cause interferences with the circumoral musculature and tongue pressure balance, and as a consequence, they develop unaltered maxillary and mandibular arch forms. Of course, the duration, frequency, and intensity of these habits play an important role, not only in the diagnosis and treatment plan but also during the whole retention phase.
Since there isn’t only one reason for digital sucking or the prolonged use of pacifiers, there isn’t only one treatment for all of them. It is important to control the habit after 2 years of age. In some patients, the help of a psychologist is valuable. Digital sucking is responsible for causing significant changes in the maxilla and in the mandible during the growth period.
In general, the maxilla becomes narrow and V shaped, the mandible tends to be retrognathic, and, as a consequence, a significant open bite is developed with proclined upper incisors and retruded lower incisors.
Due to the excessive proclination of the upper incisors, lips become incompetent and the tongue is placed between the upper and lower incisors during the swallowing process, worsening it. Also, there is a significant link between the respiration mode, the direction of the facial growth, and the development of the malocclusions (posterior cross bite and anterior open bite), due to abnormal contraction of the cheek muscles.
Hypertrophic lymphoid tissues and nasal obstruction in combination with large adenoids and tonsils are the most common cause of nasal obstruction and mouth breathing as they push the tongue forward due to pain and decrease in the amount of posterior space for the tongue.
This atypical swallowing pattern and the anterior posture of the tongue at rest prevent the eruption of the incisors and increase the anterior open bite with lower lip interposition every time the patient swallows.
In general, these young patients are sent to the speech therapist in order to improve the pronunciation of certain words, but it is important to remember that the anterior open bite is the consequence, not the cause. Also, orofacial and speech dysfunction could be com- bined with problems at the TMJ that could worsen in the future.
In addition to TMJ problems, episodes of sleep apnea could be added. The child could stop breathing several times during the night (20–40 times per hour of sleep). As a consequence, he or she would feel daytime sleepiness, headaches, fatigue, obesity, changes in personality, lack of attention at school in the morning, etc. Since sleep apnea is a progressive disorder, the consulta- tion with the specialist is very important from the first day in order to perform a multi- and interdisciplinary treatment plan and avoid relapse (Pascually et al.).
It is important to remember that sleepwalking in young children and enuresis are commonly related to open bite problems. The real question is who, when, why, and how to treat.
The higher the percentage of environmental factors in relation to the genetic ones, the better the prognosis. Among the deleterious habits, the prolonged use of pacifiers, mouth breathing, or thumb-sucking are determinants. In some patients, the help of a psychologist is fundamental to control the habits.
Unfortunately, there isn’t only one type of appliance to treat all these patients. The appliance selection has to be related to the etiology, age of the patient, seriousness of the problem, etc. The orthodontist is responsible for the appropriate selection.
The decision of whether to use a removable, fixed appliance or a combination of both is related to the etiology and the skeletal maturity in order to maximize the effectiveness of the orthodontic treatment.
The normalization of the vertical dimension is extremely challenging for the orthodontist to control, especially in high-angle patients with mouth breathing.
If problems leading to an open bite could be identified and treated early, it might be possible to minimize or even eliminate an undesirable pattern of growth.
According to the structures affected, anterior open bite can be divided into three main categories: dental, dentoalveolar, and skeletal.
Dental and dentoalveolar open bites develop as a result of prolonged mechanical blockage of the normal vertical development of anterior teeth and alveolar process (Torres et al. 2012).
The skeletal form, in turn, is characterized by a significant vertical skeletal discrepancy, with features such as counter- clockwise rotation of the palatine process, increased lower anterior facial height and gonial angle, short mandibular ramus, and increased posterior dentoalveolar height in both mandible and maxilla.
3.1 Diagnosis
Medical and dental analysis
Evaluation of growth Functional analysis
Patients’ chief complaint
Photographic and radiologic evaluation
Vertical facial pattern
Unfavorable growth pattern
The treatment goals should include the removal of the etiological and environmental factors to permit the normalization of the anterior growth development.
Until now, no consensus has been reached to determine the best time to initiate the orthopedic/orthodontic treatment. Nonetheless, it is totally accepted that the earlier the correction of the open bite begins, the better the results will be. Also, early treatment helps avoid relapse.
Myofunctional therapy is the best option to normalize mouth breathing. Control and reduction of the extrusion of the molars are fundamental to allow a counterclockwise rotation of the mandible to maintain the results.
Failure to control bad habits may be the most important reason of relapse. The role of the otolaryngologist to improve and normalize nasal breathing during the diagnosis process and speech pathology is of prime importance.
In general, anterior open bite in temporary or early mixed dentition is associated with digital sucking habit and tongue anterior interposition. Its correction is very important since otherwise the problem could worsen and turn into a skeletal alteration.
The size and length of the lips are also important to maintain a proper lip seal during day and night. Also, it is necessary to normalize the position and function of the tongue. Normally, children who breathe through their mouth have a narrow maxillary arch, protrusive incisors, Class II occlusion, convex facial profile, bags under the eyes, an open mouth posture, and narrow nostrils. The importance of the multidisciplinary treatment cannot be denied. Treatment strategies are in close relationship with etiology, facial biotype, age of the patient, and clinical experiences.
The management of the tongue thrust and mouth breath- ing involves the interception of the habit. First of all, the doc- tor has to determine that the patient can use his/her nose to breathe normally. It is important to remember that mouth breathing is abnormal and can affect the whole stomatognathic system, body posture, etc., and not only the position of the teeth. As soon as this problem is corrected, fewer consequences appear.
Different appliances could be used according to the age of the patient and his/her medical history, in order to establish a new neuromuscular pattern.
According to the etiology and the importance of the prob- lem, removable, fixed, or a combination of both types of appliances can be used. The orthodontist has the final decision.
The following examples will describe each option in detail. This 6-year, 8-month-old patient is sent to the office by her family dentist in search of a second opinion regarding her anterior open bite.
An adenoidectomy was performed 4 months earlier. Nonetheless, mouth breathing and tongue thrusting contin- ued. It was difficult for her to close and maintain the lips sealed. She used a pacifier until 4 years of age (Fig. 3.1a, b).
Her profile was convex, and the nasolabial angle was reduced. Even though she was only 6 years and 8 months of age, she had a double chin. Hyperactivity of the musculature of the lips in combina- tion with tongue thrust with abnormal tongue posture during speech was observed during the clinical examination.
The front photograph showed a significant open bite in the anterior region in combination with a midline deviation. Only the central upper and lower incisors were erupting at that time (Fig. 3.2a, b).
No posterior cross bite was present. All day and night, the tongue was placed between the upper and lower incisors which were why they could not erupt normally. Due to the presence of large cavities, some stainless steel crowns were placed on the temporary molars (Fig. 3.3a, b).
The treatment objective (Phase I) was to normalize over- bite and overjet, maintain Class I molar, control tongue thrust, improve the activity of the lips, and enhance her profile.
To achieve this objective, the use of a functional appliance is decided on. Of all the possible choices, a prefabricated functional appliance also known as Trainer System TM (Myofunctional Research Co. Australia) was chosen. It is fabricated with a special type of polyurethane and helps the correction and normalization of the muscular dysfunction.
The appliance is especially designed to stimulate anterior and lateral muscles and help to achieve normal nasal breathing. Since the material is soft, no major problems of adaptation are present (Fig. 3.4a, b).
It is recommendable that at the beginning, this appliance be used few hours during the day (2–3 h) and then all night (Fig. 3.5a, b).
After 9 months, a significant improvement of the maxillomandibular relationship was clearly observed. The anterior open bite was totally closed, and midlines were almost normalized (Fig. 3.6a, b).
The transverse development observed in some patients could be due to the buccal shields of the trainer that stimulates the lateral muscles using the same principles that Frankel regulator does.
The treatment goals were totally achieved without the use of any other appliance.
Upon analyzing the front and lateral photographs, a significant improvement in the lower third of the face was achieved. The patient could close her lips without tension, and the tongue was located in its right position not only at rest but in active position too (Fig. 3.7a, b).
These were the results 18 months later. Class I canine was achieved and Class I molar was maintained. Overjet and overbite were normalized and midlines were normal. Oral hygiene was fairly good (Fig. 3.8a, b).
The profile and smile lateral photographs confirmed the results. The lips were relaxed and the double chin was absent. A 6-month follow-up was highly recommended (Fig. 3.9a, b).
It is advisable that open bites be treated as early as possi- ble and in this way reinstate normal oral and breathing func- tions to reduce the possibility of relapse. The type of trainer (T4K) is a valid alternative to treat these open bite patients at an early age. It also helps to improve dental arch development during the early and late mixed dentition, and most importantly, this appliance helps normalize bad habits.
Also, other types of functional appliances can be used according to the orthodontist’s preferences. As always, correct diagnosis is more important than the type of the appliance used.
The comparison between the pre- and posttreatment front dental photographs showed evidence of the normalization of the anterior open bite and the parallelism between the occlusal and gingival planes.
No brackets were required to achieve the expected results. Ideally an overcorrection of the overjet and overbite is highly recommended (Fig. 3.10a, b).
A 6-month control was recommended until all the second molars erupted. Upon analyzing the lower third of the face and the nasola- bial angle, a significant improvement was confirmed. Moreover, the lips were more relaxed and the double chin was normalized (Fig. 3.11a, b).
Further studies should be conducted to analyze if the use of this treatment protocol would have a skeletal effect in patients with anterior open bite.
In general, patients with anterior open bite have a high-angle facial pattern and also have discrepancies in the anteroposterior and transverse dimensions. The retention protocol has to include a strict control of the position and function of the tongue.
This 9-year, 2-month-old patient was sent by her family dentist due to her significant midline deviation and slight Class III tendency.
Her profile was straight with a normal nasolabial angle. She snored loudly at night, very often (Fig. 3.12a, b).
The dental front photograph clearly showed the anterior open bite and the important deviation of the midlines (3 mm). She had a V-shaped maxilla (Fig. 3.13a, b).
The right second temporary molars had a Class III tendency, and there was a significant lateral cross bite on the left side that was maintained in central relation.
No TMJ symptoms were present until then, but she preferred to eat only soft food. He dental hygiene was fairly good and no cavities were present (Fig. 3.14a, b).
The panoramic Rx confirmed that no agenesias or supernumerary teeth were present, and the lateral radiograph showed normal development according to her age. The anterior open bite was clearly visible (Fig. 3.15a, b).
The treatment objectives were:
1. Align and level the arches.
2. Normalize transverse dimension.
3. Normalize overjet and overbite.
4. Achieve Class I molar and canine.
5. Control tongue thrust.
6. Long-term stability.
To achieve these objectives, the following treatment plan was designed:
Phase I
1. Rapid maxillary expansion to normalize the transverse problems
2. Speech therapy treatment to control tongue thrust
Phase II
If necessary, esthetic brackets, 0.22″ slot in order to nor- malize dental positions, will be used.
To correct the transverse deficiency, a modified hyrax appliance was suggested. The protocol of activation was twice a day. The lateral arms were bonded with composite to the temporary molars to improve stability. After 2 weeks, the inter-incisal diastema between the central incisors confirmed that the central suture was open (Fig. 3.16a, b).
The correction of maxillary constriction is very often a target for treatment in open bite patients (McNamara and Brudon 1993).
As usual, 1 month later, the diastema closed on its own, and a monthly follow-up was suggested. The anterior open bite was totally normalized with the help of a speech thera- pist. Midlines were almost corrected.
In these cases, it is highly recommendable that RME appliance be maintained in place a minimum of 6 months to prevent relapse (Fig. 3.17a, b).
At the end of the first phase of treatment, all the objectives were achieved. The overjet and overbite were normalized as well as the position of the first molars. A removable retainer used during the night was recommended to maintain the correction of the transverse dimension, until the second molars and upper canines erupted (Fig. 3.18a, b).
The lateral and smile posttreatment photographs confirmed the results that were achieved. The lips closed smoothly with- out tension and the nasolabial angle was normal (Fig. 3.19a, b). Twenty months later, the patient returned to the office seeking improvement of the position of the canines. To achieve
these results, esthetic bracket slot 0.022″ were bonded in con- junction with a 0.016″ SS wire (Fig. 3.20a, b)
A nickel-titanium open-coil spring, slightly activated, was placed on the left side to improve the position of the first upper left bicuspid (Fig. 3.21a, b).
Seven months later, upper esthetic brackets were removed and the tongue thrusting habit was totally corrected (Fig. 3.22a, b).
Front photographs at the end of the second phase treat- ment. The face was symmetrical with balanced proportions and normal exposure of the maxillary teeth. The smile and tongue positions were totally normalized (Fig. 3.23a, b).
The lateral photographs confirmed the results. The patient was able to close her lips gently in concordance with a nice and pleasant profile and a passive lip seal (Fig. 3.24a, b).
The comparison pre- and posttreatment dental front pho- tographs confirmed that the treatment objectives were totally achieved. Dental midlines were corrected and overjet and overbite were normalized. The gingival and occlusal plane were parallel and the oral hygiene was fairly good (Fig. 3.25a, b).
The importance of the normalization of the functional problems is clearly demonstrated when the following patient is analyzed.
She was 7 years, 3 months of age and was sent to the office by her pediatric doctor due to her loud night snoring that disturbed not only her sister but also her parents’ sleep. She had a convex profile, difficulty to achieve lips clo- sure, and a double chin that are typical in all mouth breathers in conjunction with a larger lower third face and the presence of circles under their eyes. Frequently, she had colds with fever and was medicated with corticoids and antibiotics.
It is important to remember that abnormal tongue posture is associated with enlarged adenoids and tonsils in addition to sucking habits and tongue thrust (Fig. 3.26a, b).
The front dental photographs clearly confirmed the ante- rior position of the tongue at rest and an important open bite of 7 mm at the incisor region (Fig. 3.27a, b). A significant cross bite was present in the right side.
The lateral views showed Class II molar on the right side and Class I molar on the left side. The temporary right canine, first and second molars, as well as the permanent first molar were in cross bite occlusion. The oral hygiene was good and no cavities were observed (Fig. 3.28a, b).
The panoramic radiograph confirmed that all the permanent teeth were present in different stages of development in accordance to her age. The open bite was confirmed on the lateral radiograph, and it was clearly visible that the respira- tory airway was obstructed (Fig. 3.29a, b).
After the consultation with the pediatrician, the following treatment plan was decided:
1. Normalize the mouth breathing pattern.
2. Improve the position of the tongue at rest.
3. Normalize the position of the right canine and molars.
4. Achieve normal overjet and overbite.
5. Long-term stability.
In order to correct the transverse problem, a fixed bonded rapid maxillary expander was suggested. The design included bands on the right and left temporary second molars to pro- tect the permanent first molars. The activation was a quarter twice a day for 2 weeks (Fig. 3.30a, b).
At the same time, she was sent to the speech therapist to normalize the position of the tongue and in this way help close the anterior open bite. After 2 weeks, the expansion was completed. It is highly recommendable that the expander be maintained in place for a minimum of 6 months to have better control over relapse (Fig. 3.31a, b).
The speech therapist had to continue working with the patient until the overjet and overbite were normalized.
A follow-up 2 months later confirmed the improvement achieved. The inter-incisal diastema was closing normally, and the position of the central incisors was normalized (Fig. 3.32a, b).
Different types of RME can be used, but it is preferable to use those without acrylic plates not only on the palatal tis- sues but also on the occlusal surfaces of the molars. The protocol of activation is determined by the orthodon- tist, but twice a day is usually sufficient. The patient was gone for 2 years and she returned without the RME. The anterior occlusion was edge to edge, and a slight open bite was still present. Cuspids and bicuspids had almost erupted (Fig. 3.33a, b).
The lateral photographs showed slight lateral open bite in the lateral incisor and canine region, and tongue interposi- tion was still present in this area (Fig. 3.34a, b).
After a long conversation with the parents and the patient, they accepted a second phase of treatment with fixed appli- ances in order to improve her dental occlusion and prevent any type of relapse of the anterior open bite (Fig. 3.35a, b).
New panoramic and lateral radiographs showed normal eruption of the cuspids and bicuspids with no evidence of root resorption.
According to Ricketts, she had a dolichofacial pat- tern with some protrusive incisors and a moderately increased lower anterior facial height and gonial angle (Fig. 3.36a, b).
Esthetic preprogrammed 0.022″ slot brackets were bonded on the upper and lower teeth with SS 0.016″ wires to align and level the arches. No extraction of bicuspids was planned at that time.
Midlines are almost coincident (Fig. 3.37a, b). No brackets were bonded on the second lower temporary molars. However, manual stripping was performed on the mesial side in order to achieve Class I canine on the left and right side (Fig. 3.38a, b).
The upper and lower arches showed great improvement. The lower second right and left temporary molars were still in place (Fig. 3.39a, b). The dentoalveolar changes were sig- nificant with a greater improvement in the incisor position and inclination. The vertical control was very important in order to avoid an increase of the lower facial height, during the growth period.
These were the results 2 months after debonding. Midlines were coincident. Overbite and overjet were almost normal and the oral hygiene was fairly good (Fig. 3.40a, b).
Right and left Class I canine and molar were obtained with good interdigitation in the bicuspids area. The gingival line and the occlusal plane were parallel (Fig. 3.41a, b).
A fixed retention wire was bonded on the upper and lower arches to maintain the position of the incisors. Longterm retention as well as a removable appliance were rec- ommended to control the function of the tongue (Fig. 3.42a, b).
The final photographs after the orthodontic treatment showed a significant improvement in the lower third of the face. She could close the lips without tension and there wasn’t a gingival smile. The dental midline was coincident with the facial one (Fig. 3.43a, b).
The profile photographs clearly showed a muscle equilibrium. The profile was still straight and the nasolabial angle was normal (Fig. 3.44a, b).
The patient returned 3 years later for follow-up of her retention wires. Her smile was better than ever and the oral muscles were completely relaxed. In the end, she had a symmetrical face with balanced proportions (Fig. 3.45a, b).
The nasolabial angle was more open even though no extractions were performed in the upper arch nor in the mandible. A nice and broad smile was achieved (Fig. 3.46a, b).
When analyzing the front photographs 3 years later, a slight relapse in the anterior region was observed. With this in mind, it was advisable to finish the case with a bigger overbite in order to avoid relapse (Fig. 3.47a, b).
Class I canine and molar were maintained. A 6-month follow-up was highly advisable in order to maintain or improve the results that were achieved (Fig. 3.48a, b).
The observation of the pre- and postfrontal dental photo- graphs showed that the treatment objectives were achieved. The gingival line and the occlusal plane were parallel, and the hygiene was very good.
This confirmed that to obtain an efficient therapeutic result, correct diagnosis and treatment timing are very impor- tant (Fig. 3.49a, b).
The comparison of the pre- and postfrontal photographs clearly demonstrated how the soft tissues were improved as a consequence of the correction of the bad habits. Now, the patient closes her lips normally.
The importance of tongue posture and tongue function cannot be denied (Fig. 3.50a, b).
The results were similar from the lateral side. She had a straight profile and closed her mouth in a normal way with reduction of the lip protrusion and decreased mentalis strain.
The nasolabial angle was less protrusive even though no bicuspid extractions were performed. There was a significant improvement in vertical skeletal and dentoalveolar relationships due to the elimination of the tongue thrust and mouth breathing. This patient confirms the theory that early treatment in conjunction with the normalization of the functional habits prevents asymmetric alveolar bone growth that affects the permanent dentition (Fig. 3.51a, b).
The present clinical case clearly demonstrates that if proper diagnosis is obtained and orthodontic biomechanics are well designed, stable results can be achieved in a patient with severe anterior open bite. The post-retention stability of open bite treatment is a controversial topic in orthodontics. Relapse is unpredictable.
The etiology could be tongue thrust because of its size or posture, respiratory problems, sucking habits, condylar resorption, direction of growth, etc.
Habit elimination is mandatory to prevent open bite relapse. How can relapse be prevented? Better diagnosis and an individualized treatment and retention plan.
Conclusions
Ideally, open bite patients should be treated as early as possible. Unfortunately, there is no specific bracket or arch wire to help the normalization of the position of the tongue. These three patients were treated with different appli- ances since the etiologic reasons at the beginning were different: the first one used a pacifier until 4 years of age and had an adenoidectomy, the second one had a persis- tent tongue thrusting habit until 9 years of age, and the third one was a combination of both.
The young patient has to understand that the appliance will help him or her to control the habit. The positive role of the parents to accompany the process was essential. From a clinical point of view, early treatment with removable or fixed appliances is more effective and reduces the length of treatment in the permanent dentition with less surgical procedures and more stability.
It is well known that environmental and neuromuscu- lar influences may alter the position of the teeth and the direction of the maxilla and mandibular growth. It is important to determine the presence or absence of naso- or oropharyngeal obstructions that can alter the position of the tongue and the mandibular posture. Dentofacial changes associated with mouth breathing and its relation with some types of malocclusions that involve the presence of long face syndrome are well rec- ognized (Linder-Aronson and Woodside 2000).
The role of the otolaryngologist and speech therapist is unquestionable in the diagnosis and treatment procedures. There is strong evidence that the earlier the open bite malocclusion is corrected, the better the prognosis will be, and of course, habit elimination is mandatory to pre- vent open bite relapse.
Ideally, the treatment has to begin when the children are 4–6 years old as most of the functional and dentofacial problems begin at this age, and also there is a reduction in the risk of trauma of the upper front teeth. The prevention of the apnea problems is more impor- tant than the correction of the snoring. Remember that snoring in children in conjunction with poor concentra- tion at school and behavioral problems are the most typi- cal signs of sleep apnea episodes in children.
Relapse is unpredictable since the etiology could be multifactorial (condylar resorption, respiratory problems, continuous tongue thrust, direction of growth, habits, etc.). It is well known that the stability after retention of the open bite treatment is a controversial issue for the orthodontists.
The effectiveness and efficiency of an early orthope- dic/orthodontic treatment, based on a correct, individual- ized, and exhaustive diagnosis, are undeniable. Long-term control is fundamental to confirm the achieved results (Huang 2002). The normalization of the anterior open bite is impera- tive taking into account the health problems that can occur later on.
Unfortunately, there isn’t a specific bracket or wire to treat all these patients nor to help in the normalization of the tongue position. The parents and the young patients have to be aware that the earlier the correction of the dysfunctional habits begins, the better and more effective the results will be. A complete multi- and interdisciplinary early treatment plan is the key to correct the anterior open bite and the func- tional disturbances associated with it.
Để truy cập toàn bộ bài viết, xin vui lòng xem thêm tại đây