Introduction
A highly acclaimed orthodontic instrument, the MEAW (Multiloop Edgewise Archwire) appliance is essential in treating a variety of malocclusions, especially class III malocclusions, in which the lower jaw extends past the upper jaw. With its distinctive multiloop design, the MEAW appliance, created by Dr. Young H. Kim in 1967, has completely changed interceptive orthodontics by allowing orthodontists to make accurate modifications to jaw and tooth alignment in many situations without the need for intrusive operations. The creation of the MEAW appliance, its clinical use, and its potential as a substitute for more intrusive treatment alternatives, such as orthognathic surgery (which aligns upper and lower jaw) are all covered in detail in this article. MEAW therapy is a non-surgical and efficient way to improve dental health and jaw alignment for patients with complex dental malocclusions.
What Is the MEAW Appliance?
The MEAW orthodontic appliance-based concept (multiloop edgewise archwire) was first developed in 1967 by Reverred Dr Young H. Kim and is now a widely adopted technique in the modern-day interceptive orthodontic field.
This technique is primarily utilized for the correction of open bite malocclusions. Current dental research shows that the Meaw technique can be extremely effective in treating any type of malocclusion, but more so used specifically for the management of class III dental malocclusion/mandibular prognathism.
The MEAW appliances are mainly constructed of prepared out using 0.016 x 0.022 dimension stainless steel (bracket of usually 0.018-inch slot) or using the 0.017x0.025 stainless steel (bracket of usually 0.022-inch slot). The arches in the appliance are supposed to retain the ideal arch form with approximately five loops on either side of the arches.
What Is Sato Concept of Class III Malocclusion?
Prof. Sadao Sato initially developed the use of the MEAW concept in interceptive orthodontics. He also has introduced several hypothesis or given an insight into the study and analysis pertaining to the etiology of skeletal and dental-based malocclusions (improper alignment of the jaws and teeth resulting in improper or misaligned bite).
According to Sato's concept, genetics would not be the only primary reason behind the occurrence of a class III malocclusion, rather there would be a local posterior tooth discrepancy instead that would be the major etiological factor for causing lower jaw or mandibular overdevelopment or prognathic lower jaw/mandible. Further in most skeletal class III malocclusion, the sphenoid bone (a complex bone located beneath the front portion of the brain, behind the eye, and at the base of the cranium) usually is misaligned in a wrong rotating force along with the vomer bone (a thin, plow-shaped bone in the skull that makes up the nasal septum's lower portion, which divides the nostrils) postero-inferiorly, leading the upper jaw to be more retruded or vertically elongated. Moreover, according to the major orthodontic hypothesis, the upper jaw would be pushed down by the undue flexion from the sphenoid bone in the posteroinferior direction, which is one of the main reasons for further causing the characteristic symptoms of very short anteroposterior dimensions in between the upper and lower jaw (maxilla to the mandible). Further Individuals with class III skeletal malocclusion also tend to have posterior tooth crowding.
What Are the Other Accepted Theories and Clinical Features of Class III Malocclusion?
According to other theories that are accepted apart from the Sato concept explained above, most of the skeletal class III relationships between the maxilla and mandible would be caused due to a lack of sagittal development or forwarded positioning of the mandible/lower jaw or a squeezing-out effect that is commonly described in orthodontic literature.
A retruded upper jaw and overdeveloped or forwarded/prognathic lower jaw that is the characteristic aspects of class III skeletal malocclusion, several clinical features would be observed to confirm the diagnosis of this orthodontic issue. The maxillofacial surgeon or the orthodontist first needs to diagnose and confirm the nature of the patient's bite and alignment of the jaw by considering the following features.
Skeletal class III malocclusion is usually characterized by the following clinical features:
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Steep mandibular plane angle on clinical and radiographic examination.
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Obtuse gonial angle and a small cranial base angle.
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Possible displacement of the glenoid fossa.
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Forward positioning of the mandible.
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Short occlusal plane in affected patients.
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Reduced anteroposterior diameter in the maxilla.
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Increased vertical growth rather than proper horizontal alignment of the maxilla.
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Labial tipping of the upper teeth, commonly accompanied by lingual tipping of the lower teeth.
What Are the Steps and Objectives of MEAW Therapy?
MEAW is hence mainly utilized for all those cases of skeletal class III malocclusion treatment that do not usually require orthognathic surgery or even the extraction protocols for intermediate teeth to gain space in the jaw usually during the surgical procedures. However, it is to be noted that in very severe cases of skeletal class III malocclusion, MEAW treatment can be also partially effective in case the affected patients are indicated for orthognathic surgery only, owing to the chronic and severe symptoms of the posterior discrepancies.
There are different steps of treatment indicated through MEAW for the management of class III malocclusion.
The treatment steps for class III malocclusion management using MEAW include:
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Leveling procedures.
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Removal of occlusal interferences.
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Establishing the proper mandibular position by pushing it backward.
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Reconstructing the correct occlusal plane direction.
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Achieving a healthy physiological bite for chewing and proper occlusion.
The objectives of MEAW treatment mainly are listed below as follows:
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First remove all the posterior tooth-based discrepancies.
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To promote intrusion of the posterior teeth, that is the premolars or molars affected.
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Consequently, these teeth are uprighted and care is taken to reconstruct the occlusal plane (as it is usually very steep and misaligned in class III).
What Are the Benefits of MEAW Therapy?
The rationale behind all these objectives in MEAW treatment is to induce the lower jaw/mandible to be adapted in a backward direction with the whole of the lower dentition that would be moved distally. Further with the uprighting of molars in the last step using the MEAW appliance, shortened class III elastics can be placed post the extraction of the third molars for aligning the jaw effectively. It is to be understood that MEAW therapy is only a non-surgical adjunct to orthognathic surgery in very severe cases of skeletal class III malocclusion. However, it can be used effectively in borderline or mild cases of class III malocclusion where patients would not be inclined to orthognathic surgery often. Further, as per the latest orthodontic research, the non-surgical treatment strategy would be effective because the correction of the patient's bite is directly related to the control of vertical dimensions and correction of the occlusal plane. Both actions are promoted effectively by using the MEAW appliance for maxillomandibular alignment.
Conclusion
In most adult patients, without the ability for any more growth of the jaw past 16 to 18 years of age, orthognathic surgery is the most widely currently indicated procedure for the management of moderate to severe skeletal class III malocclusion. However, when most patients would be refusing orthognathic surgery owing to the surgical aspects and post-operative protocols to be followed, then MEAW appliance therapy can hold promising potential in the management of borderline or mild cases of class III skeletal malocclusion.
