Relationship between masseter muscle thickness and overbite values in a Nigerian population

Objective: This study determined the relationship between masseter muscle thickness and overbite values among Nigerians. Methods: The subjects included 66 consecutive patients (21 males and 45 females) who presented for fixed orthodontic appliance treatment. Overbite values were measured from standard lateral cephalometric radiographs taken for all patients,who were thereafter divided into three groups of reduced overbite (n=22, mean -1.11+ 2.18mm), normal overbite (n=22, mean 2.59+0.50mm) and increased overbite (n=22, mean 5.21+1.39mm). The masseter muscle thickness of each patient was measured bilaterally using ultrasonography. Associations between masseter muscle thickness and different overbite values were analyzed using unpaired t-test, ANOVA and Tukey's multiple comparison analysis. Results: Mean masseter muscle thickness was 11.23 ± 2.40 mm during relaxation and 12.81 ± 2.64 mm during contraction for study participants. The masseter muscle on the habitual side of mastication of participants was generally thicker but the difference was not statistically significant (P>0.05). There was a progressive increase in masseter muscle thickness from reduced overbite through normal overbite to increased overbite groups and the differences were statistically significant (P<0.01). Tukey's multiple comparisons showed significant differences between all the three overbite groups (P<0.05). Conclusion: There was a direct relationship between the muscle thickness and overbite variations (AU)

Clinical Audit of Paediatric Magnetic Resonance Imaging Under Sedation at a Nigerian Tertiary Institution.

BACKGROUND: Magnetic resonance imaging (MRI) in paediatric patients requires them to be calm during the procedure to avoid motion artefacts in the acquired images. Sedation and/or anaesthesia is a way to achieve this. We evaluated all paediatric MRI sedations since installation of an MRI device in our hospital. MATERIAL/METHODS: We retrospectively reviewed 69 paediatric MRI sedations performed over a 5-year period using records of patients' biodata, MRI date, indication, findings and scan time, sources of referral, body region scanned, type, dose, related adverse events and route of administration of sedatives as well as image quality. RESULTS: The median age and weight of the patients were 24 months {range of 0.3 months (10 days) to 132 months (11 years)} and 11.5 kg (range of 2.6 kg to 42 kg), respectively. Males constituted 50.7% of the patients. Most participants (94.2%) were in-patients of the hospital, mainly (60.0%) referred from the paediatric unit, with slightly over one third (36.2%) of the studies performed in 2015. The commonest indication and scanned body region were macrocephaly (18.8%) and the brain (76.8%), respectively. Hydrocephalus (17.4%) was the commonest MRI finding. Sedation was planned in 66 (95.7%) patients and was successful in 68 (98.6%). Midazolam and the IV route were the commonest sedative agent and route of administration, respectively. Image quality determined by age was fair to good in 68 (98.6%) patients with only 1 patient requiring re-scanning due to motion blur. No adverse events with sedation were recorded. CONCLUSIONS: Midazolam via the IV route with or without oral route is the drug of choice for MRI sedation in children in our institution with a success rate of about 99%.