Management of the developing occlusion-late mixed dentition

Early interceptive orthodontic therapy for the reduction of factors preventing normal healthy growth of the dental arch are employed peculiarly by dentists. (Tausche et al., 2004). Depending on the dentist's knowledge and training in orthodontics, however, for the pediatric dentist the area of focus is the interceptive orthodontics. (AAPD, 2016). Interceptive orthodontics is defined as any procedure that restore the normal occlusion after the initiation of malocclusion. (Ricketts et al ,1979).

In this paper we are going to talk about the developing occlusion in the late mixed dentition, diagnosis of malocclusion and lastly the interceptive orthodontic modalities we can apply in our practice.

Late mixed dentition

Following the “first transitional phase”, which include the eruption of permanent incisors and 1st molars. Following the first transitional phase, a delay of 12 to 24 months at dental age 9-10 is noted , this is called the “inter-transitional phase”. (Profitt, 1986). Therefore, late mixed dentition stage is defined by the eruption of mandibular canine, 1st maxillary and mandibular premolar. (Profitt, 1986). Which also marks the “second transitional phase” at about dental age 11. (Profitt, 1986). Thereafter, eruption of 2nd premolars and maxillary canine defines dental age 12 followed by second permanent molars. (Profitt, 1986);(Van der Linden, 1976).

Eruption sequence and timing in the late mixed dentition.

Stages of development of group of teeth are used in the calculation of dental age. (Profitt, 2018). Dental age is determined by three characteristics, first observing which teeth emerged in the oral cavity (Harvati, 2000), secondly, extent of resorption of the primary teeth roots (Harvati, 2000), thirdly, total formation of the permanent teeth. (Harvati, 2000). Tooth frequently emerge when about three fourths of its root has already formed. (Harvati, 2000). Tooth root formation can take two-three years for the root to be completed. (Harvati, 2000).

Dental age

Late mixed dentition is defined by dental Ages 9-10. (Profitt, 2018). It is characterized by no teeth erupting but can be distinguished first by the extent of resorption of the primary canines and molars(Profitt, 2018). Secondly, by the extent of root development of their permanent successors. (Profitt, 2018). The primary canines, 1st and 2nd molars are present.(Profitt, 2018). At dental age 9, one-third of the root of mandibular canine and mandibular 1st premolar is completed. (Profitt, 2018). Root development of mandibular 2nd premolar just beginning and root development of the maxillary 1st premolar has begun and just beginning for maxillary canine and 2nd premolar. (Profitt, 2018). On the other hand, at dental age 10, one-half of the root of mandibular canine and 1st premolar completed. (Profitt, 2018). Nearly half the root of the maxillary 1st premolar is completed. Lastly completion of the roots of mandibular incisors and near completion of the roots of maxillary laterals. (Profitt, 2018). At dental age 11, mandibular canines, mandibular 1st premolars and maxillary 1st premolars erupt. (Profitt, 2018). In the mandibular arch the canine erupts just ahead of the 1st premolar. (Profitt, 2018). In the maxillary arch the 1st premolars erupt well ahead of the canine. (Profitt, 2018). The remaining primary teeth are the maxillary canine, 2nd molar and mandibular 2nd molar. At Dental age 12 remaining succedaneous permanent teeth erupt, the 2nd permanent molar in both arches are near eruption. (Profitt, 2018). Beginning of mineralization of third molars sometimes seen. (Profitt, 2018). Finally, at dental ages 13, 14 and 15, it is characterized by extent of completion of roots of the permanent teeth and root formation complete, 3rd molars should be apparent on the radiographs. (Profitt, 2018).

Space relationships in the replacement of canines & primary molars

Permanent premolars teeth size is smaller than the primary molars. (Profitt, 2018). This space difference is called leeway space, by Nance. (Gianelly, 1995). In the mandibular arch it is about 2.5mm per side and in the maxillary arch 1.5mm is available. (Gianelly, 1995).

After shedding of the primary second molars, permanent first molars move mesially – this contributes to transition from flush terminal plane to class I relationship. (Gianelly, 1995). The mandibular molar moves more than the maxillary. Differential growth of mandible relative to maxilla also contributes to this translation. (Gianelly, 1995). 3.5mm forward movement of lower molar relative to upper molar is required for transition to Class I molar relationship. (Profitt, 2018). Half of this distance is obtained from differential growth of the lower jaw and primate spaces(Early mesial shift) and the other half from the leeway space (late mesial shift). (Profitt, 2018). The amount and direction of mandibular growth is the key variable in determining the permanent dentition molar relationship. (Dimberg et al., 2015).

Etiology of malocclusion in late mixed dentition

Figure.1 demonstrates the contributing factors for malocclusion.

Disturbances of dental development

Congenitally missing teeth

Is the outcome of disturbance during initiation and proliferation stages of tooth development. (Kliegman, 2007). Anodontia is defined as the total deficiency of teeth. (Kliegman, 2007). Congenital deficiency of more than 6 teeth is named oligodontia. (Kliegman, 2007). However, absence of few teeth, less than 6 in number is called Hypodontia. (Kliegman, 2007). Hypodontia is associated usually with the most distal tooth of any given type. (Kliegman, 2007). Ectodermal dysplasia is a systemic abnormality usually associated with anodontia or oligodontia. (Itthagarun & King, 1997).

Malformed and supernumerary teeth

A malformed tooth is an abnormality that occur during the process of morpho-differentiation. (Garvey et al., 1999). Most common variation in size is the lateral incisor and 2nd premolar. (Garvey et al., 1999). Furthermore, supernumerary teeth are caused by abnormality of the initiation and proliferation stage(Kliegman, 2007), most common is the mesiodens which is a supernumerary tooth that is found usually between the central incisors in the maxilla. (Kliegman, 2007). Sporadically, double teeth can be observed in the oral cavity, happens when tooth buds fuse or geminate during their development. (Duncan et al., 1987). Fusion stands for double teeth joined together at the dentin interface but with separate pulp chambers. (Duncan et al., 1987). On the other hand, gemination stands for double teeth with a single pulp chamber. (Duncan et al., 1987).

Traumatic displacement of teeth

Trauma in the primary dentition can dislocate the permanent successor bud. (Flores et al., 2007). When the trauma occurs during crown formation also known as the calcification stage the crown of the permanent tooth is usually defected. (Flores et al., 2007). However, if it was after the crown formation then there will be a displacement of the root in relation to the crown which is also known as dilaceration. (Flores et al., 2007). Traumatically displaced permanent teeth in children should be replaced immediately because after healing (2 – 3 weeks) it is difficult to reposition as ankylosis may develop. (Flores et al., 2007).

Early loss of primary teeth

Premature loss of primary second molar causes mesial drift of permanent first molar, because eruption path of molars is mesially inclined. (Holan & Needleman, 2014). This causes posterior crowding and malalignment of premolars. (Holan & Needleman, 2014).

Premature loss of primary first molar or canine causes distal drift of incisors, due to the action of contraction of gingival fibers along with the muscle pressure from lips and cheek. (Holan & Needleman, 2014). Early loss of tooth on one side will lead to shift in the midline, asymmetry in occlusion and tendency towards crowding. (Holan & Needleman, 2014).

Eruption abnormalities

Sequence abnormalities include teeth eruption with a considerable degree of variability from chronological age, but with maintained stages of eruption. (Tortora et al., 2008). A child with precocious dental development, the mandibular central incisors and 1st molars will erupt at age 6 and could reach dental age 12 by chronological age 10. (Tortora et al., 2008). A child with slow dental development might not reach dental age 12 until chronologic age 14. (Tortora et al., 2008). Some of the causative factors for delay in the eruption can include supernumerary teeth, dense sclerotic bone and fibrous gingiva(Tortora et al., 2008), these clinical features are seen considerably in cleidocranial dysplasia. (Tortora et al., 2008). A demarcated variation in the eruption sequence can be a sign for abnormalities in normal development. (Tortora et al., 2008). The greater the deviation the greater is the likelihood of some problem. (Tortora et al., 2008).

These variations most commonly include eruption of 2nd permanent molars before premolars in the mandibular arch(Profitt, 2018),eruption of permanent canines before premolars in the maxillary arch, and significant asymmetries in eruption between left and right sides. (Profitt, 2018).

Early eruption of mandibular 2nd molars.

It tends to decrease the space for the second premolar, second premolar partially blocked out of the arch. (Profitt, 2018). In this case it is necessary to open the space for the second premolar.(Profitt, 2018).

Early eruption of maxillary canine.

Eruption of canine before 1st premolar normal in the lower arch, but abnormal in the upper. (Profitt, 2018).Canine will be forced labially as a result of space deficiency in the arch. (Profitt, 2018). Frequently asymmetries in eruption between right and left side is normal. (Profitt, 2018).

If a permanent tooth erupts on one side and its counterpart on the other side does not erupt within 6 months, a radiograph should be taken to investigate the cause of the problem. (Hudson et al., 2018).

Ugly duckling stage

At around age 9, in the maxilla we can find space between the central incisors called median diastema. (Profitt, 2018).This condition occurs before the eruption of the canines. (Profitt, 2018).The diastema may close as the lateral incisors erupt, but if the incisors are flared to the labial it may persist. (Profitt, 2018).The space tends to subside after the eruption of the permanent canines. (Profitt, 2018). The larger the diastema, the less likely that it will close by itself. (Profitt, 2018). Diastema equal or less than 2mm will close naturally, while closure of diastema more than 2mm is unlikely. (Profitt, 2018). Etiology of persistent diastema involves physical obstruction such as, mesiodens, bone lesions and high frenum attachment. (Profitt, 2018). It is also caused by congenitally missing permanent lateral incisors and habits such as thumb sucking.(profitt et al., 2013). Interceptive treatment is essential if the midline diastema is preventing eruption of permeant lateral incisors, in addition to cases were spacing and protrusion might increase the chances to traumatic injuries. (profitt et al., 2013). Treatment can involve the removal of the cause, Hawley retainer and finger spring or Fixed appliance treatment. (profitt et al., 2013).

Ectopic eruption of canines

Occurs in 1-3% of population, it is usually 85% palatally and 15% buccally. (Olive, 2017). Aetiology of the impacted canine involve space deficiency in the arch related to abnormalities of sequence of eruption (Olive, 2017), other causes involves missing lateral incisors and localized pathological lesions. (Olive, 2017).

To diagnose canine ectopia the clinical and radiological evaluation are very crucial(Hudson et al., 2010). Family history, absence of palpable canine bulge at 9-10 years, the presence of any developmental anomalies, late development of the dentition especially lateral incisor. (Profitt, 2018). Presence of crowding involves buccal displacement and spacing involves palatally displaced canine. (Olive, 2017) ;(Hudson et al., 2010).

Radiographically, panoramic x rays are recommended as a screening toot to identify ectopic eruption. However, cone beam computed tomography (CBCT) is used identify the detailed position of the canine in relation to the anatomical structures in a three-dimensional image. (Proffit et al., 2013).

Management of ectopic canine involves first and foremost extraction of primary canine after evaluating the possibility of the canine’s extrusion. (Profitt, 2018) canine shouldn’t be severely displaced with available space that can be created, and patients age is between 10-13 years. (Olive, 2017). Cervical pull headgear along with rapid maxillary expansion were frequently reported in treatment of ectopic canines. (Olive, 2017). If spontaneous eruption did not occur 12 months post extraction of primary cuspid, possibility of eruption of canines will be very slim. (Litsas & Acar, 2010).

Occlusal problems

Occlusal problems can be evaluated by the jaws and the occlusal function which involves the mastication, speech and Temporomandibular joint (TMJ) function. (Profitt, 2018). Severe malocclusion patients tend to have difficulties in mastication and speech, this emphasize the importance of proper history taking of the patients before planning any orthodontic treatment. (Doshi et al., 2011). Patients with specific speech difficulties can undergo speech therapy along with orthodontic therapy. (Doshi et al., 2011).

TMJ function is of special concern in orthodontics, any anterior or lateral shifts of the mandible upon closing are of great importance. (Profitt, 2018). A child with constricted maxillary arch will usually present with a unilateral crossbite, this is important to verify during oral examination to rule out any TMJ problems or shifts. (Profitt, 2018).

Posterior crossbite

Most commonly caused by a dental origin rather than a true skeletal asymmetry, this condition is usually apparent in the mixed dentition. (Pinto et al., 2001). Posterior crossbite is often found in children with habits such as thumb sucking. (Pinto et al., 2001). Thumb sucking habit is usually associated with constricted maxilla which leads to posterior crossbite. (Profitt, 2018).

Management of posterior crossbite include the increase in arch circumference and hence more space to the permanent teeth. (Pinto et al., 2001). It is shown that opening the intermaxillary suture in maxillary expansion is easier in younger children. (Pinto et al., 2001). W-arch appliance, Quad helix appliance and Hyrax appliance with jackscrew are often used in crossbite treatment. (Profitt, 2018). However, rapid expansion is not recommended. (Pinto et al., 2001).

Crossbite must always be overcorrected because of the high relapse rate, the retention should be atleast 3 months post maxillary expansion. (proffit et al., 2013).

Pseudo-class III

This type of malocclusion occurs when the patient tends to shift from a centric relation position to centric occlusion. (Profitt, 2018). In patients with pseudo class III this shift occurs because of the interference of the anterior teeth. (Rabee et al., 2000). The patient tends to position their jaw forward to accomplish maximum intercuspation. (Rabee et al., 2000).

Space management in the mixed dentition

Space analysis studies the space needed for teeth alignment compared to available arch space. (Profitt, 2018). In the mixed dentition Examples of space analysis include Moyers space analysis and Tanaka & Johnston analysis. (Profitt, 2018). Unerupted canines and premolars size prediction is done in the mixed dentition by radiographic and un-radiographic methods. (Kakkar et al., 2019). The sum of mesio-distal width of lower incisors is used against tables to predict the size of the unerupted permanent successors which determine the space availability. (Kakkar et al., 2019). Two scenarios are usually found after space analysis is done, first, if we observe adequate space, the management should be space maintenance until eruption of successor teeth. (Kakkar et al., 2019). Secondly, if we observe space deficiency in the dental arch, treatment of crowding and space regaining are the possible treatments. (Kakkar et al., 2019).

Space maintainers

After premature loss of primary teeth, it is necessary to consider the space maintenance of the arch space. (Kakkar et al., 2019). Important factors must be considered in the decision-making regarding space maintainers, these include the extent of root development, the position of the tooth and the distance between the erupting tooth and the dental alveolar crest. (Brothwell, 1997). The extent of space loss is larger in the maxilla compared to the mandible. (Laing et al., 2009). Regarding the root development, if more than 75% of the root is developed then, space maintainers needed for short time or not at all. (Profitt, 2018). However, 1mm movement is expected every 4 to 5 months in erupting premolars through the bone, radiographic examination is always advisable prior to any space maintain therapy. (Profitt, 2018).

Position of the tooth in the dental arch

Here we are going to discuss different clinical scenarios that we can encounter in the mixed dentition and identify which space maintainer appliance to be suitable.

1. If we encounter premature loss of primary incisors and the primary canines is erupted, there is no need for space maintainer.

2. Unilateral loss of primary canine, extract contra-lateral primary canine and use Fixed lingual holding arch in the mandibular arch, Nance Appliance in maxillary arch.

3. Premature loss of primary 1st molar either band and loop, if bilateral then lingual arch or nance appliance.

4. Loss of 2nd primary molar, if the permanent 1st molar is erupted we use band and loop, if not we use distal shoe appliance.

(Profitt, 2018)

Lingual arch space maintainer

Acts by prevention of the mesial movement of molar teeth and distal or lingual tipping of the anterior teeth (Profitt, 2018), it consists of two bands on the first permanent molar and a loop that extend all the way to the permanent anterior incisors. (Laing et al., 2009).

Lingual arch space maintainer is contraindicated before eruption of all permanent incisors because of the possible interference of the arch loop with the eruption. (Laing et al., 2009).

Nance appliance

This appliance is used in the maxillary arch, utilizing a palatal button which acts as an anchorage to resist mesial movement of the permanent molars. (Profitt, 2018). Soft tissue irritation was reported with nance appliance, regular follow up is recommended to prevent possible impingement of the palatal button. (profit et al., 2013). Transpalatal arch appliance was shown to be less irritant to the soft tissues in comparison to nance appliance. (Laing et al., 2009).

Trans palatal arch appliance

This appliance is composed of two bands that connect a U-shaped loop between the two maxillary permanent molars. (Profitt, 2018). It is indicated when more than one primary tooth is lost on one side and the other side is intact. (Profitt, 2018). The appliance functions by providing stability from the intact side to the other side for space maintenance. (Profitt, 2018).

Crowding

Usually when we encounter a patient with a primary dentition that lacks primate spaces or spacing the consequence will be crowding in 40% of the cases. (Profitt, 2018).

Crowding is multifactorial and can be due to space loss following premature primary tooth loss or discrepancy between the teeth size and the size of the jaw. (Gianelly, 1995).

Due to the anchorage of removable appliances afforded by the palatal vault, the space regaining is shown to be more efficient in the maxilla than the mandible. (Profitt, 2018). In addition, appliances in the mandible are less tolerable by patients. (proffit et al., 2013).

Figure. 2 below describes different classification of crowding and the possible treatment modalities for each class.

Disking

As a rule, there is no need for treatment when mild incisor crowding is observed during the mixed dentition. 2mm crowding in the anterior segment can resolve without treatment. (Profitt, 2018). Permanent tooth stripping should not be undertaken until all the permanent teeth have erupted and their inter-arch size relationships can be evaluated. (Bell et al., 2011).

Lip bumper

Action of the lip bumper usually by utilizing the force of the lower lip to the mandibular permanent 1st molars. (Profitt, 2018). The appliance disrupts the equilibrium forces between the lip and tongue and reliefs the forces and allow the facial movement of the incisors (profitt, 2018).

Timed/Serial extraction

Serial extraction is defined as the “The sequential removal of primary and, ultimately, permanent teeth to resolve tooth size and arch length crowding”.(Ngan et al., 1999). Indications of serial extractions are absence of skeletal discrepancies with class 1 malocclusion and normal overbite. (Wagner et al., 2000). Serial extraction is shown to be beneficial in patients with bimaxillary protrusion and in patients with crowding of greater than 10mm in the arch. (Wagner et al., 2000). On the other hand, contraindications include class II and class III malocclusion, deepbite and openbite, moderate to mild crowding of less than 5mm. (Wagner et al., 2000).

Figure.3 provides a simple guideline which summarizes the important points discussed in this paper regarding crowding.

Planned extraction

One of the common dilemmas in the pediatric dentistry practice include a clinical scenario like a permanent 1st molar with failed restoration, very close to the pulp and require endodontics plus full coverage crowns or/and general poor prognosis of 1st molar. Indications of the early or planned extraction of 1st permanent molar include patient with class I occlusion, premolar crowding, no missing permanent teeth and absence of the 3rd molar tooth-bud. (Cobourne et al., 2009).

Ideal timing of planned extraction is at the early calcification of unerupted 2nd molar root bifurcation (8-10 years). (Cobourne et al., 2009). If extraction was early; 2nd premolar will drift distally, tip and rotate and the anterior teeth will retrocline with deep bite. (Cobourne et al., 2009). However, if it was delayed, the 2nd molar will tip mesially, with spacing, poor occlusal contacts. (Cobourne et al., 2009). The 2nd premolar will migrate distally, and we will observe atrophy of alveolar bone.(Cobourne et al., 2009). Contraindications include deep bite cases, class III malocclusion and arch spacing. (Cobourne et al., 2017).

Compensating extraction stands for the extraction of the opposing tooth and this is encountered if lower 1st molar extraction is required, the removal of upper 1st molar is also done to avoid its overeruption. (Cobourne et al., 2017). However, if upper 1st molar extraction is required, we do not compensate with extraction of the lower 1st molar if healthy. (Cobourne et al., 2017).

Skeletal malocclusion

Here we are going to discuss the types of skeletal malocclusions and the possible treatments that can be performed.

Class II

The most common cause of skeletal class II was shown to be from mandibular retrognathism. (Profitt, 2018). However, it can be from maxillary excess or both. (Profitt, 2018).

Orthodontic treatment is performed in skeletal class II is done during the growth spurt period utilizing functional appliances, then followed by fixed appliances. (Profitt, 2018). The objective from this treatment is to correct the jaw discrepancy with combined dental and alveolar adjustments. (Frye et al., 2004).

Appliances that can be used in class II malocclusion include but not limited to Twin Block, Headgear, Bionater, Activater, Frankel II and Herbst appliance. (Profitt, 2018).

Functional appliances

Act by “Direct mandibular growth via altering the muscle tension at the condyle that in turn leads to accelerating the condylar growth”. (Profitt, 2018). Functional appliances are indicated in patients with skeletal class I & II malocclusion, mandibular retrognathism, short facial height and in retroclined mandibular incisors. (Profitt, 2018). In addition, the action of this appliances is increased facial height, growth inhibiting effect on maxilla and mandibular anterior repositioning. (Profitt, 2018);(Tulloch et al., 1997). However, most commonly the dental compensatory effects are apparent such as retrusion of upper anterior teeth and protrusion of lower anteriors. (Frye et al., 2009). Mesial tipping of mandibular molars and distal tipping of the maxillary molars was also reported. (Frye et al., 2009). Multiple disadvantages of functional appliances have been found sich as uunfavourable increase in the lower facial height, highly dependant on patient compliance. (Frye et al., 2009) and the time window of the use of functional appliances is narrow where it should be initiated before the growth spurt. (Frye et al., 2009). Additionally, individual tooth movements are not achievable, such as bodily movement or rotational movement which must be therefore treated with fixed appliances. (Frye et al., 2009).

Headgear

Head gears are in many shapes and forms, most commonly used headgears are high and cervical pull headgears. (Profitt, 2018). High pull headgear appliance produces a distal and upward force on the maxillary teeth and maxilla. (Ngan et al., 1996). Cervical headgear is composed of a neck strap connected to a facebow. (Ngan et al., 1996). This appliance produces a distal and downward forces on the maxilla and maxillary teeth. (Ngan et al., 1996). It is recommended that head gears must be worn 10-12 hrs/ day. (Proffit et al., 2013)

Twin block

Twin block was shown to be well tolerated by patients and it can be used in both permanent and mixed dentition. (Proffit et al., 2013). Most of the outcomes achieved by twin block functional appliances were mostly dental with a small skeletal component. (Al-Anezi, 2011).

Bionator

A bionator usually have a buccal wire to maintain the lips off the teeth and can incorporate bite blocks between the posterior teeth. (Proffit et al., 2013). The bionator also incorporates a major palatal connector to stabilize the posterior segments. (Proffit et al., 2013).

Herbst appliance

This appliance is used to guide the mandible anteriorly in a passive manner by a plunger and tube, this was shown to be an effective functional appliance due to the fact that it is fixed and does not need compliance from the patient. (Proffit et al., 2013).

Frankel II

This appliance is composed of a lingual pad behind the lower incisors with the mucosa in that area and fosters expansion of the arches with the buccal shields. (Proffit et al., 2013). The lower lip pad also moves the lower lip facially. (Proffit et al., 2013).

Class III

Class III malocclusion occurs mainly due to maxillary retrognathism, mandibular prognathism or both. (Profitt, 2018). The apparent mandibular excess is often due to maxillary retrognathism. (Baccetti et al., 1998). Mandibular growth restriction is shown to be limited; however, maxillary sutural growth can be modified. (Baccetti et al., 1998).

In treatment of class III malocclusion in the mixed dentition, the main objective is to reduce the extent of the malocclusion, enhance aesthetics and prevent traumatic occlusion until future orthodontic treatment is initiated.

Modalities of treatment for class III malocclusion include Orthodontic camouflage, Orthopedics and Orthognathic surgery. (Profitt, 2018).

Orthodontic camouflage

Mild skeletal class III discrepancy can be improved with extracting of premolars and achieving “Camouflage” in patients after the growth spurt or in adults. (Profitt, 2018).

Orthopedics

The orthopedic treatment is used for growth modification and it is only limited to growing children before adolescence. (Profitt, 2018). In case of deficient maxilla and normal mandible, maxillary protraction can be effective. (Cha, 2003). Individual skeletal patterns must be planned for each patient with Class III malocclusion. (Baik, 2007).

Appliances used in class III malocclusion include but not limited to frankel III, chin cap and facemask.

Frankel III

Frankel III appliance action is by relief of the muscular forces from the lip and buccal pad that will stimulate the forward growth of the maxilla, and with a labial bow that can restrict mandibular growth. (Guo et al., 2011). Frankel III appliance action is mainly the result of posterior and inferior rotation of the mandible and distalization of the lower incisors, with little effect on maxillary growth promotion. (Baik, 2007).

Face mask

Face mask has two parts, first is the external framework attached to the face, and secondly, internal attachment to the maxillary dentition. Studies indicate that the “combination of a bonded maxillary expander and face-mask therapy” is effective in early mixed dentition. (Chong et al., 1996).

Chin cap

Chin cup therapy must continue until the growth of the patient is completed or close to end. (Baik, 2007). In cases of severe mandibular prognathism this appliance has little effect , and there is a greater need for surgery. (Baccetti et al., 1998). In addition, this appliance must be limited to patients with a pseudo class III or a mild Class III malocclusion.

In general, the literature suggests that the evidence on the long-term efficacy of orthopedic treatment for class III malocclusion is lacking and often biased, therefore more research is needed in that field. (Woon & Thiruvenkatachari, 2017).

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