Efficacy of immediate physiotherapy after surgical release of zygomatico-coronoid ankylosis in a young child: A case report

Exploring the Importance of Corticalization Occurring in Alveolar Bone Surrounding a Dental Implant

Several measures describing the transformation of trabecular bone to cortical bone on the basis of analysis of intraoral radiographs are known (including bone index or corticalization index, CI). At the same time, it has been noted that after functional loading of dental implants such transformations occur in the bone directly adjacent to the fixture. Intuitively, it seems that this is a process conducive to the long-term maintenance of dental implants and certainly necessary when immediate loading is applied. The authors examined the relationship of implant design features to marginal bone loss (MBL) and the intensity of corticalization over a 10-year period of functional loading. This study is a general description of the phenomenon of peri-implant bone corticalization and an attempt to interpret this phenomenon to achieve success of implant treatment in the long term. Corticalization significantly increased over the first 5-year functional loading (CI from 200 ± 146 initially to 282 ± 182, p < 0.001) and maintained a high level (CI = 261 ± 168) in the 10-year study relative to the reference bone (149 ± 178). MBL significantly increased throughout the follow-up period—5 years: 0.83 ± 1.26 mm (p < 0.001), 10 years: 1.48 ± 2.01 mm (p < 0.001). MBL and radiographic bone structure (CI) were evaluated in relation to intraosseous implant design features and prosthetic work performed. In the scope of the study, it can be concluded that the phenomenon of peri-implant jawbone corticalization seems an unfavorable condition for the future fate of bone-anchored implants, but it requires further research to fully explain the significance of this phenomenon.

Measures of Corticalization

After the insertion of dental implants into living bone, the condition of the peri-implant bone changes with time. Implant-loading phenomena can induce bone remodeling in the form of the corticalization of the trabecular bone. The aim of this study was to see how bone index (BI) values behave in areas of bone loss (radiographically translucent non-trabecular areas) and to propose other indices specifically dedicated to detecting corticalization in living bone. Eight measures of corticalization in clinical standardized intraoral radiographs were studied: mean optical density, entropy, differential entropy, long-run emphasis moment, BI, corticalization index ver. 1 and ver. 2 (CI v.1, CI v.2) and corticalization factor (CF). The analysis was conducted on 40 cortical bone image samples, 40 cancellous bone samples and 40 soft tissue samples. It was found that each measure distinguishes corticalization significantly (p < 0.001), but only CI v.1 and CI v.2 do so selectively. CF or the inverse of BI can serve as a measure of peri-implant bone corticalization. However, better measures are CIs as they are dedicated to detecting this phenomenon and allowing clear clinical deduction.

Clinical Evaluation of Magnesium Alloy Osteosynthesis in the Mandibular Head

Titanium alloys are used in skeletal surgery. However, once bone union is complete, such fixation material becomes unnecessary or even harmful. Resorbable magnesium materials have been available for several years (WE43 alloy). The aim of this study was to clinically compare magnesium versus titanium open reduction and rigid fixations in mandible condylar heads. Ten patients were treated for fractures of the mandibular head with magnesium headless compression screws (2.3 mm in diameter), and 11 patients were included as a reference group with titanium screws (1.8 mm in diameter) with similar construction. The fixation characteristics (delay, time, and number of screws), distant anatomical results (mandibular ramus height loss, monthly loss rate, and relative loss of reconstructed ramus height), basic functional data (mandibular movements, facial nerve function, and cutaneous perception) and the influence of the effects of the injury (fracture type, fragmentation, occlusion, additional fractures, and associated diseases) on the outcome were evaluated. The long-term results of treatment were evaluated after 18 months. Treatment results similar to those of traditional titanium fixation were found with magnesium screws. Conclusions: Resorbable metal screws can be a favored option for osteosynthesis because surgical reentry can be avoided. These materials provide proper and stable treatment results.

Protocol for Multi-Stage Treatment of Temporomandibular Joint Ankylosis in Children and Adolescents

Treatment of temporomandibular ankylosis is challenging and frequently leads to re-ankylosis, relapse, dangerous complications and, in turn, the need for multiple operations. In this article, we present a protocol for the treatment of ankylosis of the temporomandibular joints that assumes earlier intervention with the assistance of 3D virtual surgical planning (3DVSP) and custom biomaterials for better and safer surgical outcomes. Thirty-three patients were treated due to either uni- or bilateral temporomandibular ankylosis. Twenty individuals received temporomandibular prosthesis, whereas seventeen required simultaneous 3D virtual surgical/planned orthognathic surgery as the final correction of the malocclusion. All patients exhibited statistically significant improvements in mouth opening (from 1.21 ± 0.74 cm to 3.77 ± 0.46 cm) and increased physiological functioning of the mandible. Gap arthroplasty and aggressive rehabilitation prior to temporomandibular prosthesis (TMJP) placement were preferred over costochondral autografts. The use of 3DVSP and custom biomaterials enables more precise, efficient and safe procedures to be performed in the paediatric and adolescent population requiring treatment for temporomandibular ankylosis.

Evaluation of Mandibular Growth and Symmetry in Child with Congenital Zygomatic-Coronoid Ankylosis

Ankyloses in the area of the temporomandibular joint (TMJ) are mentioned as a potential etiological factor of mandibular growth disorders and facial asymmetry. The aim of this case study was to evaluate the changes in the mandible of a child with zygomatic-coronoid ankylosis during the first five years of life, in which two adhesion release procedures were performed. The adopted symmetrical approach is based on the assumption of symmetry of the structure of the stomatognathic system in relation to the sagittal median plane. However, the assessment of pathological changes in the structure of the skeletal system was performed using an asymmetrical approach. Computed tomography techniques and a system of computer-aided diagnosis (CAD) were used in the case study. During the child’s growth, linear and angular measurements were made thrice (at the age of 16, 25 and 54 months). The degree of asymmetry was estimated in the measurements made on the right and left sides of the three-dimensional mandible. Unilateral congenital hypoplasia of the articular process and zygomatic-coronoid adhesion caused asymmetrical growth of the mandible in the child along with shortening of the mandibular branch and body on the damaged side and a visible difference in the size of the mandibular angles. Removal of the adhesions during surgical procedures made it possible to reduce the asymmetry of the mandible and catch-up growth, although at the age of five, the mandible was still smaller than the mandible in healthy peers. It was shown that the early adhesion release procedures supported by the CAD analysis enabled the restoration of mandibular symmetry.