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Digital workflows have become integral in orthodontic diagnosis and therapy, reducing risk factors and chair time with one-visit protocols. This study assessed the transfer accuracy of fully digital planned insertion guides for orthodontic mini-implants (OMIs) compared with freehanded insertion. Cone-beam computed tomography (CBCT) datasets and intraoral surface scans of 32 cadaver maxillae were used to place 64 miniscrews in the anterior palate. Three groups were formed, two using printed insertion guides (A and B) and one with freehand insertion (C). Group A used commercially available customized surgical templates and Group B in-house planned and fabricated insertion guides. Postoperative CBCT datasets were superimposed with the planning model, and accuracy measurements were performed using orthodontic software. Statistical differences were found for transverse angular deviations (4.81° in A vs. 12.66° in B and 5.02° in C, p = 0.003) and sagittal angular deviations (2.26° in A vs. 2.20° in B and 5.34° in C, p = 0.007). However, accurate insertion depth was not achieved in either guide group; Group A insertion was too shallow (-0.17 mm), whereas Group B insertion was deeper (+0.65 mm) than planned. Outsourcing the planning and fabrication of computer-aided design and computer-aided manufacturing insertion guides may be beneficial for certain indications; particularly, in this study, commercial templates demonstrated superior accuracy than our in-house-fabricated insertion guides.

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OBJECTIVES: The goal of this study was to assess the extent to which median mandibular distraction via a cemented and screw-retained full-coverage splint appliance employing a hinged expansion screw causes inclination changes in the lower first molars and widens the dental arch. METHODS: Our study included 17 patients (12 females and 5 males; average age 16 years and 3 months) who presented with transverse space deficits and pronounced dental crowding. Baseline and final mandibular casts reflecting the situations before and after 6 weeks of median distraction therapy were created, scanned, and matched via their coordinate systems. Perpendiculars were drawn at the geometric centers between the cusp tips of teeth 36 and 46 and projected against the frontal plane. The intersection angles yielded single-tooth and total inclination values for both molars, and the difference between the intermolar distances measured at the geometric centers of both teeth provided the amount of transverse expansion. RESULTS: An intraclass correlation coefficient (ICC) of >0.99 was obtained in a series of three measurements. After distraction treatment, the total inclination values between teeth 36 and 46 changed by +2.93 ± 9.14°. The corresponding single-tooth inclinations changed by +0.68 ± 6.32° and -2.25 ± 4.33°, respectively. Both molars underwent similar degrees of buccal or lingual tipping. Compared to a mean expansion of +6.9 ± 1.83 mm at the distraction screw, a distance increase of only +3.77 ± 1.27 mm along the transversal connecting teeth 36 and 46 was recorded. Pearson's correlation coefficient was 0.336 between total tipping and intermolar expansion (p=0.187) and -0.426 between total tipping and patient age (p=0.088). CONCLUSION: Expansion amounts were approximately twice as long at the expansion screw as between the first molars. This V-shaped expansion pattern was due to the hinged connections between each expansion screw and the full-coverage splints. The buccal and lingual tipping of molars measured may be due to varying heights of the posterior alveolar ridge during mixed dentition or to anatomy-related differences in the expansion-screw position. In all cases we observed a mainly parallel opening of the distraction gap on the vertical plane.

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Segmental maxillary osseodistraction is a proper method to close alveolar gaps in patients with clefts of lip, palate, and alveolus. The technique is mainly used in very wide clefts after failure of conventional bone grafting procedures. The aim of the study was to analyze problems that may occur during the distraction process. Patients with uncommon wide alveolar clefts or recurrent oronasal fistulas and patients with bilateral clefts of lip, plate, and alveolus and an additional vertical deficit of the posterior cleft segment underwent distraction procedures. The patients were subdivided according to the vector of distraction: linear (following the dental arch) and vertical. The devices for horizontal distraction were tooth-borne and manufactured to the specific clinical situation. For vertical distraction, standard devices were used. Of this sample, patients with complications occurring during or after surgery and during the distraction period were selected as the study participants. On the basis of the data collected on these complications, the need for additional bone grafting procedures was evaluated. Results suggest that modifications in preoperative planning and the construction of the distraction devices may be necessary to prevent unexpected problems in segmental maxillary distraction procedures. Considerations concerning the placement of distraction devices are discussed.

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In cases of bilateral clefts of lip and palate there is often a vertical and transversal deficit of the cleft segments. Ideally these problems can be solved orthodontically. In severe cases there is a need of surgical support. Distraction osteogenesis allows the correction of transversal, horizontal, and vertical deficits. A case of a 13-year-old girl with a bilateral cleft of lip and palate is presented. The patient had a severe deficit of the distal cleft segments concerning the vertical and transversal dimension. Osteotomy of the segments was performed and a vertical distraction followed by a transpalatal distraction procedure was used to correct the discrepancies.

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OBJECTIVES: Alveolar clefts are commonly closed by a bone grafting procedure. In cases of wide clefts the deficiency of soft tissue in the cleft area may lead to wound dehiscence and loss of the bony graft. Segmental maxillary bony transfer has been mentioned to be useful in such cases. Standard distraction devices allow unidirectional movement of the transported segment. Ideally the distraction should strictly follow the dental arch. The aim of this study was to analyze distraction devices that were adapted to the individual clinical situation of the patients. The goal was to achieve a distraction strictly parallel to the dental arch. STUDY DESIGN: Six children with unilateral clefts of lip, palate, and alveolus between 12 and 13 years of age were included in the study. The width of the cleft was between 7 and 19 mm. Dental cast models were used to manufacture individual distraction devices that should allow a segmental bony transport strictly parallel to the dental arch. Segmental osteotomy was performed under general anesthesia. Distraction was started 5 days after surgery. All distracters were tooth fixed but supported by palatal inserted orthodontic miniscrews. RESULTS: In all patients, a closure of the alveolar cleft was achieved. Two patients required additional bone grafting after the distraction procedure. The distraction was strictly parallel to the dental arch in all cases. In 1 case a slight cranial displacement of the transported maxillary segment could be noticed, leading to minor modifications of the following distractors. CONCLUSION: Distraction osteogenesis is a proper method to close wide alveolar clefts. Linear segmental transport is required in the posterior part of the dental arch, whereas in the frontal part the bony transport should run strictly parallel to the dental arch. An exact guided segmental transport may reduce the postoperative orthodontic complexity.

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OBJECTIVE: To determine the accuracy of different manufacturer's dimensions of bracket slots and stainless steel archwires and compare these against the tolerance limits given by DIN 13971 and 13971-2. Further to calculate torque play and effective torque and to compare the results to nominal torque. DESIGN: A laboratory investigation. SETTING: The Department of Orthodontics and Dentofacial Orthopedics at Medical University of Graz, Austria. MATERIALS AND METHODS: Ten upper central incisor brackets (0·022 inch) from five different bracket systems were investigated. Bracket slot height was measured with leaf gauges. The height and width of 10 stainless steel archwires with dimensions either 0·019×0·022 or 0·020×0·025 inch were measured using a micrometer. RESULTS: All measured bracket slot heights were within the upper and lower tolerance limits given by DIN 13971-2. Archwires showed measurements outside the upper and lower tolerance limits given by DIN 13971. The smallest effective torque loss (4·5°) resulted from the combination of the 0·022-inch SPEED System bracket with the 0·020×0·025-inch SPEED Wire small upper. The highest torque loss (11·7°) was found with the 0·022-inch Damon 2 bracket and the 0·019×0·025-inch ECO Charge 1 archwire. CONCLUSION: The accuracy of the manufacturers dimension is not to be taken for granted. A perfect 'finishing' still requires correction bends put in by the orthodontist.

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Segmental distraction osteogenesis in the maxillary alveolar process makes it possible to close alveolar clefts in patients with cleft lip and alveolus successfully. Dental spaces occurring in the lateral segment can subsequently be fully closed by transplanting teeth into this area. This new method of treatment is advantageous for patients with broad clefts and multiple missing teeth in the maxilla.

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