Case report of an adult female demonstrating severe anterior open bite with skeletal Class III malocclusion. The patient was treated non-surgicaily. The treatment mechanics and results are discussed.

Open bite is a deviation in the vertical relation­ship of the maxillary and mandibular dental arches and there should be a definite lack of contact in the vertical direction.¹ It is considered the most difficult malocclusion to treat since it results from interaction of multiple etiological factors.¹-² It may cause social and psychological distress as well as functional problems in related patients. The widely recognized problem in the treatment of open bite in the high tendency of relapse. To achieve a successful and stable result, however, it is essential to establish a correct diagnosis, identify the cause, locate the deformity and select an appropriate method of treatment.
Different treatment modalities were used in the treatment of open bite according to the etiology and the severity of the case. The treatment may start from self-correction, removable, functional and fixed appliances to surgical intervention in severe skeletal cases. Several case reports showed the effect of treatment with the Multi-loop Edgewise Arch Wire technique described by Kim.³ This case report describes the application of a modification of this technique for the treatment of an adult case with severe anterior open bite.

A 21 year old woman was presented to the Orthodontic Clinic of the College of Dentistry, King Saud University, who complained that her front teeth did not touch and which caused her psychological distress. Her medical history was of no relevance. She had a history of early extraction of upper right first molar and upper left second premolar. Family history revealed that one of her sisters had the same problem. The patient was very anxious to have orthodontic treatment.
Clinical Examination
Extra-oral examination revealed Class III skeletal base with an increased lower facial height. The lips were incompetent with deficient labio-mental fold.
Intra-oral examination revealed that she is in the permanent dentition with all teeth present except the upper left second premolar, upper first right molars and the third molars. Her oral hygiene was good. The molar relationship on the right side was Class III while in the left side was Class II. There was a unilateral cross bite on the right side. The canine relationship on both sides was Class III. The overjet was-0.5 mm with an overbite of -5.5 mm. There was moderate crowding in the lower labial segment with no crowding in the upper jaw (Fig. 1).
Radiographic Examination
The panoramic radiograph showed the presence of all permanent teeth except the upper left second premolar and upper right third molar, also a large restoration in the lower right first molar (Fig. 2).
The cephalometric analysis confirmed the clini­cal impression of a Class III skeletal base with ANB angle of zero degree. Mandible was posteriorly inclined with increased jaw angle and increased lower facial height. The maxillo-mandibular angle was increased indicating open basal configu­ration. Both upper and lower incisors were proc-lined. The upper lip was 3 mm behind the esthetic line and the lower lip was 3 mm ahead to the esthetic line (Fig. 3).
Diagnosis
The orthodontic diagnosis was Class Hi malo­cclusion with a skeletal open bite and incom­petent lips.
Treatment Aims

Treatment Plan
A surgical correction was planned but the patient refused it and therefore only conventional orthodontic therapy was undertaken.

Treatment Steps

Treatment Results

Post-retention Evaluation
Cephalomertic evaluation after two years of active treatment exhibited minimal changes. The molar and canine relationship remained the same. Minimal changes were observed in overjet and overbite. Clinically, slight opening of the extraction space occurred on the lower left side (Figs. 9,10,11). 

Open bite malocclusion is a complex and difficult problem to correct. There are several procedures available to treat this condition, how­ever, no one single procedure is suitable for all types.² The case report in this paper proved the success of orthodontic treatment in an adult patient with severe skeletal Class III malocclusion associated with open bite.
Shingemi et al⁴ stated "when planning treat­ment for skeletal problems of this magnitude, combined orthodontic treatment and ortho­gnathic surgery are usually recommended." How­ever, the case presented in this paper was treated only with orthodontic treatment because the patient refused surgery. A reverse curve nitinol rectangular archwire (0.016 x 0.022) for both upper and lower arches were used instead of using stainless steel rectagular archwire with multi-loops as recomended by Kim.³ The advan­tages of using reverse curve nitinol archwires are: less chair-time, less trauma to the patient's cheek, less food accumulation, facilitates brushing, mini­mizes gingival inflammation and achieves the same end results as the multi-loop archwires. The effect of both types of reverse curve archwires is intrusion and distal uprighting of the posterior teeth as well as extrusion of the anterior teeth. However, the main disadvantage of both wires is worsening of the open bite if vertical elastics were not fully used. Therefore, patient cooperation is mandatory.
Kim further suggested to band the second molars, however, the second molars were not banded in this case and the result was stable. This gives the possibility of using this technique in cases where the second molars did not erupt or were extracted early. The superimposition of the cephalometric tracings of pre-treatment and at the end of active treatment in the maxilla revealed that there was a distal uprighting of the molars with intrusion and extrusion of the upper incisors. The same was observed in the mandible. Further, the superimposition of the pre-treatment and the post-retention in the maxilla and the mandible showed that the upper and lower incisors were slightly proclined. The upper and the lower first molars remained in the same vertical relationship but moved slightly to a forward position. When analyzing the superimposition of these cases, it is of great benefit to recommend the extraction of the third molars before starting the treatment. Further, the effect of this technique on the soft tissue will minimize performing major surgery where minor surgery (e.g. genioplasty) can produce good and successful results. The treatment result of this technique showed few skeletal changes although several dental significant improvements were brought about. Both upper and lower incisors were extruded and showed significant retroclination and the overbite increased to positive overlap while the molars either  intruded  or were distally tipped. Some
changes tend to relapse to some degree but remained significantly stable two years after discontinuation of the treatment. (Table 1) Hence, the success of treatment of open bite cases depends on establishing proper diagnosis, applying proper treatment plans and mechanics. Further, patient cooperation is vital especially when instructed to use the vertical elastics full-time. The use of the vertical elastic is a key factor in the success of treatment together with the mechanics applied. Newman⁵ stated 'There are three typical results that can be noted when treating open bite malocclusion. Some cases remain as originally treated, with minor changes, some cases improve, and some cases, frankly relapsed." Accordingly, the case reported in this paper belongs to the first category.
Normal swallowing exercise was considered as a factor in obtaining stable result and it may minimize the effects of anterior tongue position and tongue thrust during swallowing.⁴ Firm and strong conclusion regarding the success of this treatment modality cannot be drawn unless such treated cases are large in number and followed up for several yea

1. A simple and effective technique was used for the treatment of a difficult malocclusion case was described.
2. Successful and stable result was achieved.
3. The treatment brought about few skeletal changes but several dental improvements.
4. Patient cooperation is one of the key success of the treatment. 

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