Sella turcica morphometrics in subjects with down syndrome.

OBJECTIVE: Since the number of patients diagnosed with Down syndrome seeking orthodontic treatment is increasing, clinicians could contribute by applying diagnostic modalities used frequently in the orthodontic field for research purposes. Thus, The aim of the present study is to implement morphometric methods to investigate the size and shape of sella turcica in subjects with Down syndrome. MATERIALS AND METHODS: In this retrospective study, archive records of 24 individuals with Down syndrome were compared to 48 healthy controls matched for age and gender. Parameters such as sella anterior, midpoint, and posterior height were measured, as well as sella width, area, and length were calculated. Independent sample t-tests were applied for the comparison of differences in sella turcica dimensions. Geometric morphometric analysis of the sella was performed with, implementing methods such as Procrustes superimposition and principal component analysis. Statistical significance was set at p<0.05. RESULTS: Statistically significant differences were found for sella anterior height, sella midpoint height, sella posterior height, sella maximum height, sella length, and sella area. All the aforementioned values were significantly increased in the Down syndrome subjects (p<0.05). Principal component analysis (PCA) depicted a statistically significant difference in sella shape between patients with Down syndrome and healthy controls (p<0.05). CONCLUSIONS: Subjects with Down syndrome presented significantly increased sella turcica dimensions as well statistically significant differences in shape compared to healthy controls.

Does surgically assisted maxillary protraction with skeletal anchorage and Class III elastics affect the pharyngeal airway? A retrospective, long-term study.

Objective: Surgically assisted maxillary protraction is an alternative protocol in severe Class III cases or after the adolescent growth spurt involving increased maxillary advancement. Correction of the maxillary deficiency has been suggested to improve pharyngeal airway dimensions. Therefore, this retrospective study aimed to analyze the airway changes cephalometrically following surgically assisted maxillary protraction with skeletal anchorage and Class III elastics. Methods: The study population consisted of 15 Class III patients treated with surgically assisted maxillary protraction combined with skeletal anchorage and Class III elastics (mean age: 12.9 ± 1.2 years). Growth changes were initially assessed for a mean of 5.5 ± 1.6 months prior to treatment. Airway and skeletal changes in the control (T0), pre-protraction (T1), post-protraction (T2), and follow-up (T3) periods were monitored and compared using lateral cephalometric radiographs. Statistical significance was set at p < 0.05. Results: The skeletal or airway parameters showed no statistically significant changes during the control period. Sella to nasion angle, N perpendicular to A, Point A to Point B angle, and Frankfort plane to mandibular plane angle increased significantly during the maxillary protraction period (p < 0.05), but no significant changes were observed in airway parameters (p > 0.05). No statistically significant changes were observed in the airway parameters in the follow-up period either. However, Sella to Gonion distance increased significantly (p < 0.05) during the follow-up period. Conclusions: No significant changes in pharyngeal airway parameters were found during the control, maxillary protraction, and follow-up periods. Moreover, the significant increases in the skeletal parameters during maxillary protraction were maintained in the long-term.

Orofacial Manifestations Associated with Muscular Dystrophies: A Review.

The aim of this review is to evaluate the developmental, functional, and morphological aspects of the craniofacial complex in patients with myotonic dystrophy type 1 (DM1), Facioscapulohumeral muscular dystrophy (FSHD), and Duchenne muscular dystrophy (DMD). The degree of disease onset and severity varied from patient to patient, and most parameters indicated a greater degree of deterioration in older patients. It was found that all the muscular dystrophies studied showed altered craniofacial morphology, with malocclusion as the most consistent clinical characteristic. Particularly DM1 patients, who are the most studied, showed significant vertical aberration and post-normal occlusion. DMD patients are reported mainly with altered dental arch dimensions which influence functional capacities. Data for FSHD patients are very limited, but facial asymmetry and muscular weakness appear to be the most prominent findings. Patients with muscular dystrophies present deviations in growth and development as well as in orofacial morphology. Increased prevalence of malocclusions, of both skeletal and dental origins, characterize patients with muscular dystrophies. Different dentofacial characteristics are reported among patients with different types of muscular dystrophies. Further research is needed to clarify the orofacial phenotypic expression of muscular dystrophies.

Orofacial Muscle Weakening in Facioscapulohumeral Muscular Dystrophy (FSHD) Patients.

BACKGROUND: Facioscapulohumeral muscular dystrophy is the third most commonly found type of muscular dystrophy. The aim of this study was to correlate the D4Z4 repeat array fragment size to the orofacial muscle weakening exhibited in a group of patients with a genetically supported diagnosis of FSHD. METHODS: Molecular genetic analysis was performed for 52 patients (27 female and 25 male) from a group that consisted of 36 patients with autosomal dominant pedigrees and 16 patients with either sporadic or unknown family status. The patients were tested with the southern blotting technique, using EcoRI/Avrll double digestion, and fragments were detected by a p13E-11 telomeric probe. Spearman's correlation was used to compare the fragment size with the degree of muscle weakening found in the forehead, periocular and perioral muscles. RESULTS: A positive non-significant correlation between the DNA fragment size and severity of muscle weakness was found for the forehead (r = 0.27; p = 0187), the periocular (r = 0.24; p = 0.232) and the left and right perioral (r = 0.29; p = 0.122), (r = 0.32; p = 0.085) muscles. CONCLUSIONS: Although FSHD patients exhibited a decrease in muscular activity related to the forehead, perioral, and periocular muscles the genotype-phenotype associations confirmed a weak to moderate non-significant correlation between repeat size and the severity of muscle weakness. Orofacial muscle weakening and its association with a D4Z4 contraction alone may not have the significance to serve as a prognostic biomarker, due to the weak to moderate association. Further studies with larger sample sizes are needed to determine the degree of genetic involvement in the facial growth in FSHD patients.