Symphyseal fracture in a three-month-old infant

Mandibular fractures are rare in infants, and diagnosis can be easily missed due to the difficulty in obtaining an adequate history and the subtle signs. A high index of suspicion and detailed history taking from the caregiver are mandatory to pick up these cases.There are a plethora of management options that have been reported in dealing with such fractures. They range from conservative management to internal fixation by absorbable plates. While conservative management does not interfere with mandibular growth and teeth development, any surgical intervention can carry this risk. Nevertheless, a severely displaced fracture may need anatomical reduction and fixation to allow early nutrition.This study reports a 3-month-old male infant with a fracture in the mandibular symphysis who underwent reduction of the fracture and circummandibular fixation using immobilisation by an acrylic splint for 4 weeks. His long-term follow-up after 20 months showed adequate dentition with proper healing of the fracture site.

Dentoskeletal effects of Twin Block appliance in patients with Class II malocclusion

Background and aim. Class II malocclusions are most commonly seen in orthodontic practice and in the recent times Twin Block appliance has been the most popular and widely used among removable functional appliances for the correction of Class II malocclusion in growing patients. The aim of this retrospective study was to evaluate the dentoskeletal effects produced by the Twin Block appliance for the correction of Class II division 1 malocclusion with retrognathic mandible. Methods. Pre-treatment (T1) and post-treatment (T2) lateral cephalograms of 30 patients treated with Twin Block appliance (mean age = 10.8 ± 1.2 years) for the correction of class II division 1 malocclusion were compared with the 30 untreated class II control patients (mean age 11.2 ± 0.8 years) who did not undergo any treatment during this period. Both the groups were evaluated for the dentoskeletal changes using 24 angular and linear cephalometric measurements. The differences between the pre and post-treatment were calculated using a paired t-test. Results. The cephalometric analysis revealed that the Twin Block appliance stimulated mandibular growth and statistically significant differences were found between the two groups. Twin Block patients showed a statistically very high significant (p<0.001) increase in mandibular length (6.02 mm) compared with the control group (0.3 mm). ‘Headgear effect’ on the maxilla, increase in lower anterior facial height, significant reduction of overjet, overbite and Class I molar relationship was achieved in the Twin Block group. However, no significant changes appeared in the control group. Conclusion: The results of the present study conclude that the Twin Block appliance is effective in the treatment of Class II malocclusion and this is due to a combination of skeletal and dentoalveolar changes in both the arches.

Clinical and Molecular Study of the NOG Gene in Families with Mandibular Micrognathism

Objectives Previous studies showed that noggin gene (NOG) sequence alterations, as well as epigenetic factors, could influence mandibular development. The aim of this study was to analyze clinical characteristics, NOG gene sequences, and promoter methylation sites in patients with mandibular micrognathism. Materials and Methods A total of 35 individuals of five Colombian families were subject to clinical and cephalometric analysis for mandibular micrognathism. One nonaffected individual of each family was included as a control. DNA was isolated from whole blood sample from all individuals by salting out method. Nine NOG gene fragments were amplified by polymerase chain reaction (PCR) and sequenced. Identification of CpG islands for methylation analysis at the NOG gene promoter was performed by MSP-PCR kit (Qiagen R). Statistical Analysis A descriptive statistical analysis was carried out evaluating the presence or absence of genetics variants and the methylation sites in the NOG gene. Results NOG sequence results of affected individuals with mandibular micrognathism for one of the families studied demonstrated that they were heterozygous for 672 C/A (new mutation). For a second family, individuals were heterozygous for 567 G/C (single nucleotide polymorphism [SNP] RS116716909). For DNA analyzed from all patients studied, no methylations were observed at the NOG gene promoter region. Conclusion Our results suggest that 672 C/A and 567 G/C variants could be involved in the presence of mandibular micrognathism. Moreover, lack of methylation sites at the NOG gene promoter region of all individuals studied suggests possibly other epigenetic factors could modulate mandibular growth. The search of genetic variants related with mandibular micrognathism will allow to predict in an integral way the development patterns of the patients and therefore establish a better clinical treatment.

Skeletal Class II Malocclusion Treatment with Combined Twin Block and Lip Bumper Appliances: A Case Report

Functional appliances have been used over a century in clinical orthodontic treatments for skeletal Class II malocclusion patients. Its popularity is attributed to its high patient adaptability and ability to produce rapid treatment changes. The twin block and lip bumper can be combined depending on the patient’s cases. The purpose of therapy with twin block is effective in mandibular growth deficiencies to induce supplementary lengthening of mandibular by stimulating increased growth at the condylar cartilage. The patient was a ten-year-old male patient with skeletal Class II malocclusion. He had a convex facial profile, SNA (sella, nasion, A point) angle of 77.5°, SNB (sella, nasion, B point) angle of 73.0°, ANB (A point, nasion, B point) angle of 4.5°, overjet of 6.5 mm, overbite of 11/41 = 5.0 mm, 21/31 = 4.5 mm, abnormal upper labial frenulum, crossbite in the second left premolar of maxilla, crowded anterior teeth of mandibular, deficiency of mandibular growth, lower lip sucking habit, anterior teeth of maxilla with diastema and proclination. Orthodontic treatment for patient is a combination of twin block and lip bumper appliances. After seven months, frenectomy is used to eliminate and correct the spacing in the frenulum. After 10 months, the patient’s skeletal and profile had improved to skeletal Class I malocclusion, SNA angle of 78.0°, SNB angle of 75.0°, ANB angle of 3.0°, overbite and overjet of 4.0 mm, and the lower lip sucking habit had stopped. Twin block and lip bumper appliances are particularly good alternative treatment in managing selected cases of skeletal Class II malocclusion.

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.

A theoretical analysis of longitudinal temporomandibular joint compressive stresses and mandibular growth

ABSTRACT Objectives To determine if temporomandibular joint (TMJ) compressive stresses during incisor biting (1) differed between growing children over time, and (2) were correlated with Frankfort Horizontal-mandibular plane angle (FHMPA, °) and ramus length (Condylion-Gonion (Co-Go), mm). Materials and Methods Three-dimensional anatomical geometries, FHMPA and Co-Go, were measured longitudinally from lateral and posteroanterior cephalographs1 of children aged 6 (T1), 12 (T2), and 18 (T3) years. Geometries were used in numerical models to estimate subject-specific TMJ eminence shape and forces for incisor bite-forces of 3, 5, and 8 Newtons at T1, T2, and T3, respectively. TMJ compressive stresses were estimated via two steps: First, TMJ force divided by age-dependent mandibular condylar dimensions, and second, modified by loading surfaces' congruency. Analysis of variance and Tukey honest significant difference post-hoc tests, plus repeated measures and mixed effects model analyses were used to evaluate differences in variables between facial groups. Regression analyses tested for correlation between age-dependent compressive stresses, FHMPA, and Co-Go. Results Sixty-five of 842 potential subjects had T1-T3 cephalographs and were grouped by FHMPA at T3. Dolichofacial (FHMPA ≥ 27°, n = 36) compared to meso-brachyfacial (FHMPA&lt; 27°, n = 29) subjects had significantly larger FHMPA at T1-T3, shorter Co-Go at T2 and T3 (all P &lt; .01), and larger increases in TMJ compressive stresses with age (P &lt; .0001). Higher compressive stresses were correlated with larger FHMPA (all R2 ≥ 0.41) and shorter Co-Go (all R2 ≥ 0.49). Conclusions Estimated TMJ compressive stress increases from ages 6 to 18 years were significantly larger in dolichofacial compared to meso-brachyfacial subjects and correlated to FHMPA and Co-Go.