Prevalence of dens invaginatus in young Israeli population and its association with clinical morphological features of maxillary incisors.

Dens invaginatus is an anomaly mostly observed in maxillary incisors. This study aimed to assess the prevalence of dens invaginatus in maxillary incisors in young Israeli population and to study its potential association with clinical coronal morphological features. Data was collected from periapical radiographs and clinical photographs of patients from Orthodontics Department between 2006 and 2018. Radiographic characteristics were evaluated and compared to clinical coronal morphological features. Statistical analysis was performed using the Pearson chi-square test with statistical significance set at p < 0.05. The sample included 1621 maxillary incisors from 547 patients. Dens invaginatus was observed in 422 (26%) of these teeth. Maxillary lateral incisors were more affected than central incisors. In 103 patients dens invaginatus was unilateral, while in all other cases it was bilateral. Unique clinical morphological characteristics were observed in 88% of the teeth that exhibited radiographic evidence of dens invaginatus. Dens invaginatus Type I was most frequently observed, accounting for 90% of the teeth. A significant association between clinical coronal morphological features and dens invaginatus was detected. Dens invaginatus is common in maxillary incisors of the study population. Several clinical morphological features may predict the presence of dens invaginatus.

Upper Lip Horizontal Line: Characteristics of a Dynamic Facial Line.

Background: Upper lip appearance received major attention with the introduction of diverse treatment modalities, including lip augmentation, rhinoplasty surgery, and dental treatment designed to support the upper lip. Our objectives were to define the prevalence and characteristics of the upper lip horizontal line (ULHL), which is a dynamic line appearing during a smile, in relation to gender, malocclusions, aging, and facial morphology. Methods: First, the prevalence and gender distribution of ULHL was examined from standardized en-face imaging at full smile of 643 randomly selected patients. Second, cephalometric and dental cast model analyses were made for 97 consecutive patients divided into three age groups. Results: ULHL appears in 13.8% of the population examined, and prevailed significantly more in females (78%). The prevalence of ULHL was not related to age nor to malocclusion. Patients presenting ULHL showed shorter upper lip and deeper lip sulcus. The skeletal pattern showed longer mid-face, shorter lower facial height and greater prevalence of a gummy smile. Conclusions: Female patients with short upper lip, concavity of the upper lip, and gummy smile are more likely to exhibit ULHL. The ULHL is not age-related and can be identified in children and young adults. Therefore, it should be considered when selecting diverse treatment modalities involving the upper lip.

Morphologic changes of the nasopalatine canal related to dental implantation: a radiologic study in different degrees of absorbed maxillae.

BACKGROUND: Implant rehabilitation of the edentulous anterior maxilla remains a complex restorative challenge. Intricate preexisting anatomy dictates meticulous and accurate osteotomy planning. With progressive bone loss, the alveolar crest may approach anatomic structures. The nasopalatine nerve and vessels may ultimately emerge from the ridge crest. The radiologic changes of the nasopalatine canal were evaluated in different resorption phases of the premaxilla alveolus with regard to dental implantation. METHODS: The study consisted of 207 subjects who had maxillary computed tomography scans before dental implantation. The Lekholm and Zarb classification was used to divide images according to the residual bony ridge: Class A (control group) and classes B to E (study group). Anatomic mapping of the nasopalatine canal structure was carried out in both groups. RESULTS: The canal diameter was wider along the degree of ridge resorption from classes A to E in all dimensions, mainly in the palatal opening (P <0.01), middle area (P <0.001), and nasal area. The mean diameter of the enlargement was 1.8 mm, which reached 5.5 +/- 1.08 mm (P <0.01) in type E bone. In the severely resorbed ridges (classes C through E), when the palatal opening was situated on the ridge, it occupied a mean of 35.6% (13% to 58%) of the area devoted to implant placement. Tooth loss was the main reason for ridge resorption (P <0.01). CONCLUSIONS: Canal diameter enlargement was greater anteriorly to the ridge and posteriorly to the palatal bone, mainly because of tooth extraction. The atrophy of disuse may influence surrounding structures, similar to the maxillary sinus tendency to expand into surrounding bone mainly after tooth loss.