רפואת הפה והשיניים - עיתון ההסתדרות לרפואת שיניים בישראל - כרך ל"ז, גיליון מס' 2 אייר תש"פ

extended periods of time. The four main modalities commonly used for treatment, include Frankel’s functional appliances, face-mask reverse-pull headgear, chin cup and skeletal anchorage, as listed in table 1. Early treatment is recommended because skeletal changes are more likely in young children, aged 8 or younger, and the maximal age for which data show improved results is approximately 10-11 (23) The following provides a brief overview of each modality, including advantages, pitfalls, highlighting possible cooperation modes between the treating dentist and the orthodontic team: 1. Frankel’s FR-III appliance (Fig 2 ) The FR III appliance, recommended only for mild cases (2), is a functional appliance best suited to treat cases where the mandible is positioned posteriorly and is rotated clockwise. It is fitted with pads that stretch the upper lip forward. The main goal is to bring the maxilla forward and to restrict the growth of the mandible. This appliance requires significant patient compliance because it requires wearing 24 hours a day for 2.5 years of active treatment followed by an additional 3 years for retention (24). There is however little, if any, true forward movement of the maxilla while the chin rotates downwards and backwards (2, 25). Overall, improvement in facial appearance and inter-arch relationships is attributed mainly to dentoalveolar changes (26). Patients undergoing treatment with such appliances benefit from early detection and treatment of dental caries and bruxism. They should be monitored to detect development of alveolar defects. The general dental practitioner plays an important role in promoting hygiene, and in overall encouragement to complete treatment and wear the appliance for more than 5 years. 2. Reverse-pull headgear - Facemask (Fig 3) Only twenty years ago, Delaire introduced the facemask as a possible treatment alternative for SkCl3 anomalies in young children (15). Generally, it is recommended for use when the condition is mild to moderate, and is less demanding on the patient than the FR III (2). It is preferred to postpone maxillary

protraction until the permanent first molars and incisors have erupted. The facemask appliance can be connected to the maxillary arch by a removable splint, by a fixed appliance with extension arms to a trans-palatal arch, or by direct attachment to the maxillary bone (skeletal anchorage). Fairly heavy forces should be applied for 12-14 hours per day to achieve meaningful protraction (three mm after one year of treatment (13, 27)). When using the facemask anchored to teeth, it is expected that, in addition to skeletal movement, dentoalveolar changes may occur. Forward movement of the maxillary dentition may be observed, as well as lingual tipping of the lower incisors. Downward and backward rotation of the mandible (also known as ‘clockwise rotation’ – Fig 4 ), results in an increase of the lower anterior facial height (28, 29). While SkCl3 is a sagittal discrepancy between the upper and lower jaw, if it is also accompanied with a transverse malformation, the latter should be addressed as soon as possible. Maxillary expansion by opening the midpalatal suture leads to correction of any existing posterior crossbite, elimination of functional mandibular shift upon closure, and an increase in the space in the upper arch (30). In addition, it might move the maxilla forward, thus increasing the effectiveness of the facemask. A known example of an expansion appliance is the jackscrew appliance that can be activated at different frequencies: rapid maxillary expansion (RME; 0.5mm /day), semi-rapid (0.25mm/day), or slow (l mm/week). Palatal expansion can also be achieved with a bone borne device, so that the force is applied directly to the bone, without applying a load on the teeth, thus producing a change that is more skeletal (2). Sometimes, opening the jackscrew according to the orthodontist instructions at home is unpleasant and may frustrate patients and parents. The general dental practitioner can help motivate such patients or worried parents, while ensuring that the screw was opened properly and there is no unplanned pressure or laceration in the soft tissue. Even without such patient frustration, the general dental practitioner will contribute to treatment success by ensuring good hygiene, by early detection and treatment of caries,

10

.2 רפואת הפה והשיניים, אייר תש״פ, כרך ל״ז, גיליון