Relationship between Malocclusion, Loss of Cervical Lordosis and Atlanto-occipital Instability: A Randomized Controlled Trial

This study aims to investigate the relationship between malocclusion, cervical lordosis, and atlanto-occipital instability (AOI). By analyzing cephalometric and cervical spine measurements, this research seeks to provide insights into how malocclusion may influence cervical posture and to emphasize the importance of considering postural alignment in orthodontic diagnosis and treatment planning. This study aimed to investigate the relationship between malocclusion (ANB angle) and loss of cervical lordosis (cervical Cobb angle). A total of 155 patients (77 female, 78 male) who applied to Kastamonu Training and Research Hospital were included in the study. SNA, SNB, and ANB angles were measured using full-head tomography, and skeletal classification was performed. Cervical lordosis was evaluated using the Cobb method. Additionally, to analyze atlanto-occipital instability, measurements of the basion-dental apex distance, Atlas Anterior Tubercle-Posterior Dens (ADI) distance, lateral mass steps in the rotational plane, Powers Ratio, and clivus canal angle were performed. Statistical analyses revealed a moderate negative correlation between skeletal class and cervical Cobb angle (Pearson correlation coefficient $$r=-0.32$$, $$p=0.001$$; Spearman correlation coefficient $$r=-0.29$$, $$p=0.002$$). Similarly, a negative correlation was found between the ANB angle and cervical Cobb angle (Pearson correlation coefficient $$r=-0.28$$, $$p=0.003$$; Spearman correlation coefficient $$r=-0.26$$, $$p=0.004$$). These findings suggest that malocclusion may not only affect dental and maxillofacial structures but also influence cervical spine posture. The study found that cervical lordosis angle increased in skeletal Class 2 individuals, and this condition may be associated with postural disorders. Additionally, the prevalence of skeletal Class 3 malocclusion has increased by approximately 50% since 2004. These findings highlight the importance of considering cervical spine posture in orthodontic treatment planning and the need for a multidisciplinary approach between orthodontists and orthopedists. This study demonstrates a relationship between skeletal class, ANB angle, and cervical lordosis. Future studies with larger sample sizes will provide a more detailed understanding of this relationship.