Textbook for Orthodontic Therapists. Ceri Davies

       Leave the malocclusion and accept the teeth and their discrepancies as they are.

       All patients must be informed of all the risks if they wish to take the no treatment option.

       Anterior expansion screw or Z springs (double cantilever):These are two active components which are found on a removable appliance.Either component can be used to procline the incisors to turn them into a class II div I.

       Correct deepbite:A flat anterior bite plane can be incorporated on the removable appliance to help reduce the deepbite.This allows passive lower molar eruption and incisor intrusion.

       An alternative to a removable appliance is a sectional fixed U2–2 to turn the malocclusion into a class II div I.

       Any of these six appliances can be used:Clark’s twin blockBionatorHerbstMedium opening activator (MOA)Clip‐on fixed functional (COFF)Frankel.

       These posture the mandible forward to reduce the upper anterior segment and procline the lower anterior segment to reduce the overjet.

       Extractions:Maxillary first premolars only:This is considered in a mild–moderate crowded case with a well‐aligned lower arch.In this case the maxillary first premolars are considered because more space is gained from these teeth. Due to the need for more space anteriorly to reduce an overjet, this will help to retract the upper incisors.Maxillary first premolars and mandibular second premolars:This is considered in a mild–moderate case with crowding in both arches.Maxillary first premolars would be considered to help retract the upper incisors to reduce an overjet. These teeth are considered because more space is needed anteriorly for retraction.Mandibular second premolars would be considered for moderate crowding in the lower arch, because less space is needed to align the dentition due to there only being mild–moderate crowding.Maxillary and mandibular first premolars:This is considered in a moderate–severe crowded case in both arches.Due to more space being needed in both arches, more space is gained by extracting the first premolars, therefore this would be a consideration in severe cases.Mandibular first premolars are to be extracted if a patient has severe crowding in the lower arch

       Intermaxillary elastics:With a class II div II case, elastics would be considered.Class II intermaxillary elastics would be used.Class II elastics help to retract the upper anterior segment and procline the lower anterior segment, which will help to reduce the overjet.In class II div II cases, patients present with deepbites. Class II elastics would work in our favour with this, as they allow molar extrusion, which will help to reduce the patient’s deepbite.

       Space closure:Once the upper anterior teeth are in the correct inclination, the same class II div I procedures will apply to space closure.Fixed appliances will close all remaining spaces once the overjet has reduced.For example, a patient has had the upper first premolars and lower second premolars extracted. In the upper arch, lacebacks will be placed from the upper canines to the upper first permanent molars to achieve a class I canine relationship once the canines are in class I and the anterior segment has achieved its correct inclination, creating an overjet, and chain elastic will be placed U2–2 to retract the remaining overjet. In the lower arch, lacebacks are used to relieve lower anterior crowding, and once the teeth are aligned the posterior teeth will be brought mesially to close the remaining spaces.

       Correct deepbite:A patient in a class II div II will present with a deepbite, which can be corrected in this stage.There are numerous ways of correcting a deepbite with fixed appliances:Bond and engage 7s on archwirePosition anterior brackets more incisally – this would work in the clinician’s favour by positioning them incisally from the bond‐up appointmentReverse curve archwiresComposite/metal bite turbosFixed FABPClip‐on FABPIntermaxillary elastics – class IIHeadgear – cervical low pull

       Correct deepbite:Headgear can be used to correct a deepbite.The type of headgear that would be used is the cervical low pull headgear.This type of pull is below the occlusal plane, which is used to distalise and extrude the maxillary molars. By doing this it encourages a backward growth rotation, which will reduce the deepbite.

       Mandibular segmental procedure:This type of procedure would be done in a severe deepbite case.This is where incisions are made lower 3–3 and the anterior segment is moved down to correct the deepbite.

       Bilateral sagittal split osteotomy (BSSO):For mandibular advancement.Done in patients with a retrognathic mandible, as it advances the mandible.