Influence of skeletal class in the morphology of cervical vertebrae: A study using cone beam computed tomography

Objectives:To quantify the prevalence of cervical vertebrae anomalies and to analyze any association between them and skeletal malocclusions or head posture positions in the same study.Materials and Methods:Two hundred forty patients who were attending the Department of Orthodontics of the University of Valencia for orthodontic treatment were selected and divided into three groups: skeletal Class I (control group, 0° <ANB < 4°), Class II (ANB ≥ 4°), and Class III (ANB ≤ 0°) according to ANB Steiner angle. The morphology of the first five cervical vertebrae was analyzed with cone beam computed tomography to identify any anomalies. Intra- and interobserver error methods were calculated.Results:Dehiscence and fusion of one unit (both 23.3%) and partial cleft (11.7%) were the most frequent anomalies, while occipitalization was the least common (3.3%). Dehiscence anomaly was observed when the control group was compared with Classes II and III and partial cleft anomaly when Class I was compared with Class III. Furthermore, NSBa and ss-N-sm/ANB angles were associated with partial cleft anomaly, while NSL/NL angle and extended head posture were associated with fusion anomaly.Conclusions:Fusion, dehiscence, and partial cleft were the most frequent cervical vertebrae anomalies. Dehiscence and partial cleft were found to present statistically significant differences between Class I and Classes II and III. Cervical vertebrae anomalies and head posture were associated with fusion.     

Biomimetic Aromatic Hydroxylation of Selected Diphenylmethane Derivatives

Many oxidation systems using iron or manganese porphyrins as catalysts and various oxygen atom donors have been reported to mimic cytochrome P-450-dependent monooxygenases^1–3). Such systems are very efficient for epoxidation of alkenes and reasonably for alkane hydroxylation. Few authors also reported about the activity to hydroxylate aromatic rings. In these cases low yields were found for hydroxylation of anisole, benzene, naphthalene, and toluene^4–7). Biomimetic systems based on metalloporphyrin catalysts can be used for preparative oxidation of some substrates and appear particularly useful for the preparation of oxidized metabolites of drugs or other xenobiotics.