Journal of Dental Medicine

Background and Aims: Considering the extensive connections of anatomical components in the head and neck region, it is expected that a change in one of the components of this functional unit will have effects on other parts. The aim of this study was to investigate the effect of correction of class III skeletal relationship with orthognathic surgery on the angles between cervical vertebrae.
Materials and Methods: This descriptive-analytical retrospective study was conducted in 1403 at the orthodontic department of Babol Dental School. 30 patients with class III skeletal malformations in the age group of 18 to 48 years who underwent orthognathic surgery (single jaw or double jaw) and had a good quality lateral cephalometric radiography were randomly selected and available based on entry and exit criteria. Dependent variables including 13 parameters in the cranial (angles of SNA, SNB, ANB and Wits App), cervical (the angle between the OPT and CVT lines with each other and with the true perpendicular line) and craniocervical area (the angle of the OPT and CVT lines with the horizontal planes of the head, including the mandibular and palatal plane) of the head and neck were used to evaluate the angles between the cervical vertebrae. The data were analyzed using SPSS22 software and independent t-test, and in case of non-normality, Will-Coxon test was used.
Results: In this study, a total of 30 samples were examined. None of the measured parameters of the cervical area before and after surgery showed a statistically significant change (P<0.05). By comparing the angles between the cervical vertebrae, the PP/CVT angle in the craniocervical region showed statistically significant changes (P=0.024). The values of PP/OPT, MP/OPT, SN/CVT, and MP/CVT angles increased slightly after surgery, but they were not statistically significant (P≥0.05), which showed a relative increase in the tension of the head on the upper part of the cervical spine.
Conclusion: Changing the position of the jaw following orthognathic surgery could cause head extension, but it had no effect on the position of the first 4 cervical vertebrae.

Background and Aims: Dentists’(specialists and general practitioners) perceptions of smile esthetics, which are often shaped academically based on standard criteria and hard and soft tissue relationships, may differ from those of the general public and patients, potentially failing to meet patients’ expectations of treatment. This study aimed to assess and compare the views of dental specialists, general dentists, and members of the general public regarding the influence of different labio-palatal inclinations of maxillary incisors on smile esthetics.
Materials and Methods: This descriptive cross-sectional study was conducted in 2024 on general dentists, dental specialists, and laypersons. General dentists and specialists practicing in Mazandaran Province were recruited, while laypersons were selected through convenience sampling from patients attending the Faculty of Dentistry in Babol-Iran. One male and one female subject were chosen based on the clinical and lateral cephalometric criteria, and two photographs (neutral facial expression and smiling) were taken of each. After image editing, five final photographs of each subject were prepared and presented in a questionnaire to evaluate participants’ perceptions of smile esthetics according to different labio-palatal inclinations of maxillary incisors, rated on a five-point Likert scale. Data were analyzed using SPSS software with independent t-tests and ANOVA.
Results: A total of 92 laypersons, 47 general dentists, and 141 specialists (47 orthodontists, 47 restorative dentists, and 47 oral and maxillofacial surgeons) participated in this study. Across all three groups, the most attractive male smile was associated with the -5° inclination (medium negative), whereas, the most attractive female smile was rated at 0°. Conversely, the least attractive smile in all groups was the −10° inclination (severe negative) in female images. Photographs with −10° inclination received the lowest scores for both male and female subjects. Specialists assigned lower mean scores to the 0° inclination images compared to general dentists and laypersons.
Conclusion: The divergence between dentists’ and laypersons’ perceptions of the impact of different labio-palatal inclinations of maxillary incisors on smile esthetics highlights the need for greater attention to patients’ expectations and treatment goals.