|Year : 2017 | Volume
| Issue : 2 | Page : 72-75
Management of Class I Type 3 malocclusion using simple removable appliances
Neha Bhati, Zhora Jabin
Department of Pedodontics and Preventive Dentistry, D.J College of dental science and Research, Ghaziabad, Uttar Pradesh, India
|Date of Web Publication||9-Aug-2017|
Department of Pedodontics and Preventive Dentistry, D.J College of Dental Science and Research, Ghaziabad, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
According to Dewey's modification of angle's malocclusion, Class I Type 3 malocclusion is the Class I malocclusion with anterior crossbite. This case report illustrates the treatment of the 13-year-old patient, with a crossbite of the maxillary right permanent central and lateral incisors. Two upper acrylic removable appliances, each with an expansion jackscrew, were used to correct the crossbite. The total active treatment time was 6 months, and the treatment outcome was successfully maintained for the subsequent 6 months. General and pediatric dentists, as well as orthodontists, may find this technique useful in managing crossbite cases of the permanent dentition by the removable appliance and utilizing the discussion and illustrations for further clinical guidance.
Keywords: Crossbite, expansion screw, malocclusion, removable appliance
|How to cite this article:|
Bhati N, Jabin Z. Management of Class I Type 3 malocclusion using simple removable appliances. J Interdiscip Dentistry 2017;7:72-5
| Clinical Relevance to Interdisciplinary Dentistry|| |
Dentist may find this as easy, effective and less expensive approach for correction of cross-bite cases.
| Introduction|| |
A malocclusion is a misalignment or incorrect relation between the teeth of the two dental arches when they approach each other as the jaws close. It can broadly be classified as an intra-arch malocclusion, inter-arch malocclusion, and skeletal malocclusion.
Depending on the sagittal relations of teeth and jaws, malocclusions can be divided mainly into three types according to Angle's classification system published 1899.
This classification is based on, where the buccal groove of the mandibular first molar contacts the mesiobuccal cusp of the maxillary first molar:
- On the cusp (class I, neutroclusion, or normal occlusion)
- Distal to the cusp by at least the width of a premolar (Class II, distocclusion)
- Mesial to the cusp (Class III, mesiocclusion).
However, there are also other conditions, for example, crowding of teeth, not directly fitting into this classification. Many authors have tried to modify or replace Angle's classification. This has resulted in many subtypes and new systems.
Dewey's modification of angles Class-I malocclusion
- Type 1 - Anterior teeth crowding
- Type 2 - Maxillary incisor proclination
- Type 3 - Anterior cross bite
- Type 4 - Posterior cross bite
- Type 5 - Permanent molar drifts mesially.
Crossbite is a term used to describe abnormal malocclusion in the transverse plane. It has a reported incidence of 4%–5% and usually becomes evident during the early mixed dentition period. Anterior crossbite is defined as a situation in which one or more primary or permanent mandibular incisors occlude labially to their antagonists (or when one or more maxillary incisors are lingual to their antagonists). It can be a major esthetic and functional concern and may lead to abnormal enamel abrasion or proclination of the mandibular incisors, which, in turn, leads to thinning of the labial alveolar plate and/or gingival recession. Mandibular shift caused by abnormal mandibular movements may place strain on the orofacial structures, causing adverse effects on the temporomandibular joints and masticatory system. Spontaneous correction of such malocclusion has been reported to be too low to justify nonintervention, and the rate of self-correction was shown to range from 0% to 9%. Therefore, interceptive treatment is often advised to normalize the occlusion and create conditions for normal occlusal development.
Bonding brackets to the four maxillary incisors in combination with banding the two maxillary permanent first molars (2 × 4 fixed appliance) are one of the methods used for the correction of anterior crossbite with fixed appliances. It has been reported to effectively manage anterior crossbite in the mixed dentition as well as in the adult dentition. This method has the advantages of requiring little or no patient compliance or alteration of speech. Other reported treatment modalities for the correction of anterior crossbite include rare earth magnetic appliances, fixed acrylic inclined planes, bonded resin composite slopes, and multiple sets of Essix-based appliances.
Removable appliances have the advantages of easier maintenance and oral hygiene care for young patients, utilization of palatal anchorage, and the ability to move a selected block of teeth. The literature includes management techniques for unilateral crossbite using removable appliances with mid-sagittal expansion screws.
This case report aims to provide general and pediatric dentists with a simple technique to manage anterior crossbite in the permanent dentition. Illustrations of treatment progress and appliance design are included for further clinical guidance.
| Case Report|| |
A 13-year-old boy came to the Department of Pedodontics and preventive dentistry of D.J College of Dental Science and Research with the complaint of irregularly arranged teeth. Extraorally, he had a balanced face with a pleasant profile. Intraorally, he presented in the permanent dentition stage with Class I Type 3 malocclusion (Class I molar relationship on both sides, with the right maxillary incisors tipped palatally) and dental maxillary midline shifting towards the right side. The overbite was deep (100% on the left maxillary central incisor), and an anterior crossbite of the maxillary right permanent central and lateral incisors was evident [Figure 1]a,[Figure 1]b,[Figure 1]c.
|Figure 1: (a) Preoperative. (b) Preoperative study model in occlusion. (c) Preoperative maxillary study model to carry out carey's space analysis|
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Treatment planning and progress
Based on the above findings, the patient was scheduled for treatment to restore normal occlusion and alleviate the underlying functional shift. The study model was made and Carey's space analysis was done and accordingly the appliance design was formulated.
At preoperative stage, the tooth material and arch space discrepancy as according to Carey 's space analysis was 3mm, henceforth an appliance with mid-palatal jack screw was de signed, in which two finger spring were incorporated to control the deviation of left central and lateral incisors toward right side and posterior bite plane (about 4 mm thick) to disengage the bite and facilitate tooth movement [Figure 2]a. This first removable appliance was activated in the department quarter turn twice a week for 3 months. Once the cross bite appeared to be corrected the bite plane was reduced and slowly got removed to achieve posterior occlusion [Figure 3]a,[Figure 3]b,[Figure 3]c.
|Figure 3: (a) Crossbite correction after 3 months. (b) Study model after 3 months. (c) Maxillary study model after 3 months|
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After 3 months the first appliance was replaced by another removable appliance which is simple hawley's with a midpalate jackscrew [Figure 2]b. This was to further expand the maxilla and labial bow to align the maxillary teeth. At this operative stage, the tooth material and arch space discrepancy according to Carey's space analysis was 1mm. This appliance was also activated twice a week quarter turn for next 3 months, till the desired result achieved [Figure 4]a,[Figure 4]b,[Figure 4]c.
|Figure 4: (a) Postoperative intaoral maxillary occlusion. (b) Postoperative study model. (c) Postoperative study model|
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Hence, the patient was asked to visit the department every twice a week for activating the jackscrew a quarter turn and the patient was instructed to wear the appliance full-time (day and night) except for eating and teeth cleaning. The patient was also instructed to clean the appliance as well, and handle it gently, avoid holding its wire extensions or edges while cleaning.
Upon treatment completion, the second appliance was planned to replace as a retainer to ensure the stability of the corrected malocclusion. The parents consented to the treatment plan. Follow up was done once in a month for next 6 months. After 6 months retainer was removed and the patient was recalled for follow-up after 3 months for next 6 months.
| Discussion|| |
In cases of unilateral crossbite, determining the correct treatment approach for each individual case is the key to treatment success and stability. The clinician must first distinguish crossbites of dental origin from those of skeletal origin. Dental crossbite involves localized tipping of a tooth or teeth and does not involve the basal bone. Pseudo Class III malocclusion is another example of dental anterior crossbite that needs to be differentiated from sagittal skeletal discrepancies. It involves retroclination of maxillary incisors that cause the mandible to shift forward. That is why treatment of these cases should aim to correct maxillary incisor inclination.
The maxillary arch displayed an asymmetric shape due to palatal tipping of the right central and lateral incisor. The mesial and distal line angles of the respective maxillary and mandibular left central incisors acted as a guide plane during the development of the shift, resulting in an axial tipping of these teeth. Therefore, treatment was geared to alleviate the anterior crossbite first and then control the remaining transverse discrepancy. It should be noted that cases with symmetrical arches could benefit from symmetric expansion even in the presence of unilateral crossbite and mandibular shift. In such cases, the amount of intermaxillary transverse discrepancy is usually reduced to less than a full bilateral crossbite.
In regard to the bite plane, clear instructions should be included to specify the thickness of the acrylic and the amount of tooth separation. For the first appliance, an acrylic thickness of 4 mm was specified (i.e., barely enough to disengage the anterior crossbite tooth). Increased and unnecessary amounts of bite opening may lead alteration of the vertical relationship and the patient's decreased compliance.
In general, the recommended activation frequency of similar appliances is every second or third day. In this case, we followed a quarterly twice a week activation protocol, which was found to be efficient and effective in the management of this case. Activation every 3rd day is recommended during the 1st week of therapy for improved patient comfort and acceptance. Other authors advocate activation twice a week and once a week.
The duration of treatment with removable appliances is reported to range from 6 to 12 weeks. With a slower expansion rate, treatment can take up to 6 and 12 months. The first and second appliance therapies lasted for 3 months, respectively, which is in agreement with the above-mentioned range.
The Hawley retainer was used for 6 months. The recommended retention period for similarly treated cases is 4–6 months (or for a period at least equal to that required for crossbite correction). After being out of retention for 4 months, the case demonstrated good stability. Increased treatment time and cost have been associated with the use of removable appliances versus fixed (e.g., quad-helix) for crossbite correction. Nevertheless, treatment of the present case was confined to the expected treatment time and matched the reported treatment duration using similar removable appliances. This highlights the importance of case selection and the necessity of enlisting patient and parental compliance before the start of treatment. In case of relapse, fixed orthodontics along with other orthopedic appliance may be required to complete the case.
| Conclusions|| |
A simple removable appliance for the correction of anterior unilateral crossbite with functional shift was presented. Thorough clinical assessment and accurate diagnosis must be performed to plan proper treatment strategies and appliance design. General practitioners and pediatric dentists can utilize this technique to manage cases with similar malocclusions.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]