Correction Of Unilateral Posterior Crossbite Research Articles

A systematic review concerning early orthodontic treatment of unilateral posterior crossbite.

The aim of this study was to assess the orthodontic treatment effects on unilateral posterior crossbite in the primary and early mixed dentition by systematically reviewing the literature. A literature search was performed by applying the Medline database (Entrez PubMed) and covering the period from January 1966 to October 2002. The inclusion criteria were primary and early mixed dentition with unilateral posterior crossbite, randomized controlled trials (RCT), prospective and retrospective studies with concurrent untreated as well as normal controls, and clinical trials comparing at least two treatment strategies without any untreated or normal group involved. Two reviewers extracted the data independently and also assessed the quality of the studies. The search strategy resulted in 1001 articles, and 12 met the inclusion criteria. Two RCTs of early treatment of crossbite have been performed, and these two studies support grinding as treatment in the primary dentition. There is no scientific evidence available to show which of the treatment modalities, grinding, Quad-helix, expansion plates, or rapid maxillary expansion, is the most effective. Most of the studies have serious problems of lack of power because of small sample size, bias and confounding variables, lack of method error analysis, blinding in measurements, and deficient or lack of statistical methods. To obtain reliable scientific evidence, better-controlled RCTs with sufficient sample sizes are needed to determine which treatment is the most effective for early correction of unilateral posterior crossbite. Future studies should also include assessments of long-term stability as well as analysis of costs and side effects of the interventions.

Correction of morphological and positional asymmetry in early mixed dentition with functional unilateral crossbite

Unilateral posterior crossbite with functional mandibular shift occurs as a sequelae of constricted maxillary arch, which is usually seen in children between 3 and 12 years of age. Early treatment of this condition helps prevent facial asymmetry, proper functioning of temporomandibular joint, masticatory muscle, and proper development of dentition. Functional unilateral posterior crossbite correction using fan-shaped expander can provide differential expansion. Fan-shaped expander was used in a patient with constricted maxilla having functional unilateral posterior crossbite with asymmetric condylar position and led to the development of favorable differential expansion and correction of asymmetry.

A customized quad helix: an appliance for management of unilateral posterior cross-bite

Posterior crossbites are most common malocclusion observed in both primary and permanent dentition. Lateral shift of the mandible is one of the effects exhibited in patients with posterior crossbite. The other effects associated are asymmetrical condylar positioning, neuromuscular disturbances with difference in loading patterns and the corresponding asymmetrical maxillo-mandibular dentoskeletal adaptations. The prevention of these effects requires early intervention of orthodontic treatment to achieve a stable occlusion in early stages of development. Achieving a normal closure pattern with elimination of functional shifts through correction of transverse discrepancy harmonizes the detrimental dentofacial esthetics. However, the restoration of harmony should be achieved during periods of dynamic growth. Early permanent dentition correction is less time consuming and more physiologically tolerable treatment options. This case report describes about a customized quad helix for the correction of unilateral posterior crossbite correction in a 13-year-old patient. Keywords: Appliances, Cross-bites, Orthodontics.

Three-dimensional evaluation of forced unilateral posterior crossbite correction in the mixed dentition: a randomized controlled trial.

The objectives of this study were to assess the three-dimensional (3D) treatment changes (palatal surface area and volume) of forced unilateral posterior crossbite correction using either quad-helix or removable expansion plate appliances in the mixed dentition, and to compare the treatment changes with the three-dimensional changes occurring in age-matched untreated unilateral posterior crossbite patients as well as in subjects with normal occlusion and with no or mild orthodontic treatment need. Six-arm parallel group multicentre randomized controlled trial. One-hundred and thirty-five patients with unilateral posterior crossbite with functional shift were recruited. The patients were randomized by an independent person not involved in the trial. The randomization used blocks of 25, and the patients were randomized into the following five groups: quad-helix treatments in specialist orthodontic clinics (QHS), quad-helix treatments in general dentistry (QHG), removable expansion plate treatments in specialist orthodontic clinics (EPS), removable expansion plate treatments in general dentistry (EPG), and untreated crossbite (UC). Twenty-five patients with normal occlusion who served as normal controls were also included in the trial. Blinding of the outcome assessor and data analyst was accomplished. Data on all children were evaluated on an intention-to-treat basis, regarding 3D palatal surface area, palatal projection area, and palatal shell volume; two-dimensional linear measurements were registered at the same time. After treatment, the surface and projection area and shell volume increased in the four treatment groups (QHS, QHG, EPS, and EPG). QHS increased significantly more than EPG for the surface and projection area. The QHS and EPS had significantly higher mean difference for shell volume. The trial considers a short-term evaluation. After treatment, there were no significant differences between the four treatment groups and the normal group, which implies that the surface and projection area together with the shell volume for the four treatment groups and the normal group were equivalent. The trial was registered with https://www.researchweb.org/is/sverige, registration number: 220751.

An RCT on clinical effectiveness and cost analysis of correction of unilateral posterior crossbite with functional shift in specialist and general dentistry.

To evaluate the costs of quad-helix (QH) and removable expansion plate (EP) treatments performed either in specialist or general dentistry for the correction of unilateral posterior crossbite with functional shift in the mixed dentition. Four-arm parallel group multicentre randomized controlled trial. One hundred and ten patients with unilateral posterior crossbite with functional shift were recruited. The patients were randomized by an independent person not involved in the trial. The randomization used blocks of 20 and into the following four groups: QH treatments in specialist orthodontic clinics (QHS), QH treatments in general dentistry (QHG), EP treatments in specialist orthodontic clinics (EPS), and EP treatments in general dentistry (EPG). Blinding was accomplished of the outcome assessor and data analyst. A cost analysis was performed with reference to intention-to-treat (ITT), regarding direct costs, indirect costs, and societal costs (the sum of direct and indirect costs) for calculations of successful treatments alone and for retreatments when required. To determine which alternative has the lower cost, a cost-minimization analysis was undertaken, based on that the outcome of the treatment alternatives were broadly equivalent, so the difference between them reduces to a comparison of costs. In the QHS group, 28 of 28 patients were successfully corrected compared to 23 of 27 in the QHG group. Treatment with expansion plate was less successful: 18 of 27 patients in the EPS group and 18 of 28 in the EPG group. QH treatment performed in specialist orthodontic clinics had significantly lower costs than QH or EP treatment accomplished in general dentistry as well as EP treatments in specialist orthodontic clinics. Costs depend on local factors and should not be directly extrapolated to other locations. Treatment of unilateral posterior crossbite in the mixed dentition is recommended to be performed by a specialist orthodontist using the QH appliance. The trial was not registered.

Repousser les limites de la dimension transversale. Asymétrie faciale, volume du palais et posture linguale chez les enfants ayant une occlusion croisée unilatérale postérieure : évaluation tridimensionnelle d’un traitement précoce

Unilateral posterior crossbites have been reported to be one of the most prevalent malocclusions of the primary dentition in Caucasian children. Facial asymmetry due to lateral mandibular displacement in unilateral posterior crossbite, if not treated in the primary dentition period, may lead to an undesirable growth modification which results in facial asymmetry of skeletal origin. Irregular tongue function and posture have also been diagnosed as important etiological factors. Early orthodontic treatment seems to be profitable and desirable to create conditions for normal dental, functional and skeletal development of the orofacial region. Treatment success after correction of unilateral posterior crossbite in the primary dentition is highly questionable, as it is very difficult to objectively assess correction of facial asymmetry and irregular tongue function and posture in small, growing children. Although facial photography is an important diagnostic tool in orthodontics, its main disadvantage is that it represents a three dimensional subject in two dimensions. Tongue posture and function during clinical examination are difficult to assess and is therefore unreliable. Contemporary 3D diagnostics in unilateral posterior crossbite enables uninvasive, valid and objective assessment of facial morphology, palatal volume, tongue function and posture. It can, therefore, become in the future an important part of morphological and functional diagnostics in orthodontics and dentofacial orthopedics before, during and after orthodontic treatment.

Three-dimensional assessment of palatal change in a controlled study of unilateral posterior crossbite correction in the primary dentition

The aim of this study was to quantify the palatal change in three groups of children: children with a unilateral posterior crossbite (TCB) who were treated, children with untreated unilateral posterior crossbite (UCB), and children without a crossbite (NCB). Study casts of 60 Caucasian children in the primary dentition (20 TCB, 20 UCB, and 20 NCB), aged 5.4 ± 0.7 years, were collected at baseline (T1) and at 1-year follow-up (T2). Both TCB and UCB groups had unilateral posterior crossbite and midline deviation. The TCB group was treated using a cemented acrylic splint expander in the upper arch. The study casts were scanned using a laser scanner and palatal surface area, palatal volume, and symmetry of the palatal vault were evaluated and compared between the three groups. At T1, the palatal volume of TCB (2698 mm(3)) and UCB (2585 mm(3)) was significantly smaller than that of NCB (3006 mm(3); P < 0.05, analysis of variance test). After treatment, the palatal volume of the TCB group (3087 mm(3)) increased and did not differ from the NCB group (3208 mm(3)), whereas the UCB (2644 mm(3)) had a significantly smaller palatal volume than the NCB or TCB groups (P < 0.05). The increase of palatal volume in the TCB group (389 mm(3)) was significantly greater than in the UCB (59 mm(3)) and NCB (202 mm(3)) groups. The symmetry of the palatal vault was greater than 90 per cent in all three groups at T1 and at T2. Treatment of unilateral posterior crossbite in the primary dentition has a significant effect, particularly on the palatal volume increase.

Three-dimensional evaluation of early crossbite correction: a longitudinal study

The aim of this longitudinal study was to assess whether correction of unilateral posterior crossbite in the primary dentition results in improvement of facial symmetry and increase of palatal surface area and palatal volume. A group of 60 Caucasian children in the primary dentition, aged 5.3 ± 0.7 years, were collected at baseline. The group consisted of 30 children with a unilateral posterior crossbite with midline deviation of at least 2 mm (CB) and 30 without malocclusion (NCB). The CB group was treated using an acrylic plate expander. The children's faces and dental casts were scanned using a three-dimensional laser scanning device. Non-parametric tests were used for data analysis to assess differences over the 30 months period of follow-up. The CB children had statistically significantly greater facial asymmetry in the lower part of the face (P < 0.05) and a significantly smaller palatal volume (P < 0.05) than the NCB children at baseline. There were no statistically significant differences between the two groups at 6, 12, 18, and 30 months follow-ups. Treatment of unilateral posterior crossbite in the primary dentition period resulted in an improvement of facial symmetry in the lower part of the face (P < 0.05) and increase of the palatal surface area and palatal volume (P < 0.001). At 30 months, relapse was observed in eight children (26.7 per cent). Treatment of unilateral posterior crossbite in the primary dentition improves facial symmetry and increases the palatal surface area and the palatal volume, though it creates normal conditions for normal occlusal development and skeletal growth.

Stability of unilateral posterior crossbite correction in the mixed dentition: A randomized clinical trial with a 3-year follow-up

The long-term stability of posterior crossbite correction in the mixed dentition has not been sufficiently evaluated. Our aim was to compare long-term outcomes in patients with crossbite correction by using matched controls with normal occlusion. After 35 patients were treated for crossbite with a quad-helix or an expansion plate, we used randomized controlled trial methodology to follow them for 3 years posttreatment. All had fulfilled our pretreatment criteria: mixed dentition, unilateral posterior crossbite, no sucking habits, and no previous orthodontic treatment. Transverse relationships, maxillary and mandibular widths, overbite, overjet, arch lengths, and midlines were registered on the study models immediately before and after treatment and at the follow-up 3 years after treatment. The matched control group comprised 20 subjects with normal occlusion and was compared with the first and last registrations for the treated groups. At follow-up, changes in the treatment groups were equal and stable. The changes were comparable with the control group. All other changes were minor and had no clinical implications. The long-term effect of crossbite correction on midline deviation was unpredictable. If crossbite is successfully corrected by the quad-helix appliance or the expansion plate, similar long-term stability is achieved. However, in treated patients, mean maxillary widths never reached those of normal control subjects.

Correction of unilateral posterior crossbite in the mixed dentition: A randomized controlled trial

From an evidence-based point of view, correction of posterior crossbite is not sufficiently evaluated. Thus, the aims of this study were to compare and evaluate the effectiveness of different treatment strategies to correct unilateral posterior crossbite in the mixed dentition by using the randomized clinical trial methodology with an untreated control group. Sixty patients participated in the study. All met the following inclusion criteria: mixed dentition, unilateral posterior crossbite, no sucking habits, and no previous orthodontic treatment. The patients were randomized into 4 groups: quad-helix, expansion plate, composite onlay, and untreated control. The success rates, amounts of maxillary and mandibular expansion, and treatment times were registered. The quad-helix appliance was superior to the expansion plate in success rate and treatment time. Treatment with the expansion plate was unsuccessful in one third of the subjects. Crossbite correction with composite onlay in the mixed dentition was ineffective, and spontaneous correction in the mixed dentition did not occur. If unilateral posterior crossbite is planned to be corrected in the mixed dentition, this study clearly confirmed that treatment with the quad-helix is an appropriate and successful method.

Long-term Stability of Unilateral Posterior Crossbite Correction

To evaluate the stability of orthodontically corrected unilateral posterior crossbite in patients treated either by rapid maxillary expansion or with slow expansion devices in the early (mean age 7.2 years, n = 50) or late mixed dentition (mean age 9.9 years, n = 50). The observation periods were approximately 8 years for the early treatment groups and 6.5 years for the late treatment groups. The measurements were made on plaster casts at the following time points: before treatment (T1), after crossbite correction (T2), at the end of active orthodontic treatment (T3), and about 2 years after the end of active treatment (T4). Midline deviation and the skeletal classification of the malocclusion were also evaluated. Almost 80% of the treated patients showed long-term stability of the corrected unilateral posterior crossbite. More than 70% of the patients were treated for the mandibular midline deviation. At the end of active treatment, 50% of the patients showed a skeletal Class III craniofacial morphology. The results emphasize that determination of the correct treatment approach for the individual patient is the basic principle underlying the therapeutic success in unilateral crossbite cases. In patients where a broad lower arch is a cofactor in the etiology of the lateral crossbite, the treatment approach should be focused on both arches and not be limited to the constricted upper arch.

Grinding is effective in early orthodontic treatment of unilateral posterior crossbite

PubMed and the Cochrane Controlled Clinical Trials Register were searched. Reference lists from retrieved articles were also searched by hand for additional studies. For inclusion, an article had to satisfy the following criteria: cases in primary and early mixed dentition with unilateral posterior crossbite; be a randomised controlled trials (RCT) or prospective and retrospective studies with concurrent untreated as well as normal controls; clinical trials must have compared at least two treatment strategies without any untreated or normal control group involved; and be written in English, German, French or a Scandinavian language. Data extraction was carried out independently and in duplicate. Quality of the studies was assessed and categorised as low, medium and high. Interexaminer conflicts were resolved by discussion to reach a consensus. The search identified 1001 articles, of which 12 met the inclusion criteria. Only two RCT of early treatment of crossbite have been performed, and these two studies support grinding as treatment in the primary dentition. As treatment strategies, quad-helix (QH), expansion plates and rapid maxillary expansion (RME) are effective in the early mixed dentition with high success rates. There is, however, no scientific evidence available that shows which of the treatment modalities, that is, grinding, QH, expansion plates or RME, is the most effective. Most of the studies have the serious drawback of lack of power because of small sample size, bias and confounding variables, lack of method error analysis and blinding in measurements, and deficient or lack of statistical methods. Thus, the studies were not of high enough quality level to draw any evidence-based conclusions. Better-controlled RCT with sufficient sample sizes are needed to obtain reliable scientific evidence identifying which treatment is the most effective for early correction of unilateral posterior crossbite. Future studies should also include assessments of long-term stability as well as analysis of costs and side-effects of the interventions.