Optimal sites in infrazigomatic crest according to craniofacial morphology.

Introduction: The infrazygomatic bone crest and other extra-alveolar regions represent a viable option for the placement of temporary anchorage devices when distalizing the upper arch. This approach allows for the movement of the dentition without concern for potential collisions between dental structures. Nevertheless, it is of the utmost importance to conduct a thorough examination of the anatomy of this region prior to the placement of mini-implants in order to prevent potential injuries, such as maxillary sinus perforations. The objective of the present study was to quantify the depth of the infrazygomatic crest and evaluate its correlations with age, gender, skeletal class, and vertical pattern. Methods: The study sample of this cross-sectional, retrospective study consisted of 201 cone-beam computed tomography (CBCT) scans collected from patients treated at the Orthodontic Master's Program of the University of Valencia and at a private dental clinic. The CBCT scans were collected over a period of five years, from January 2017 to May 2022. The total and intra-alveolar lengths were defined and measured at three points: the distal roots of the maxillary second molars, the distal roots of the maxillary first molars and the mesial roots of the maxillary first molars. These measurements were taken on both the right and left sides, using the Carestream 3D Imaging system (Atlanta, GA).
Results: The total length at the mesiobuccal level of the first molars was found to be significantly longer on both sides (P=0.001). The intra-alveolar length exhibited statistically significant differences between the right and left sides, with those of the left side exhibiting greater length (P<0.001). The normodivergent patterns demontstrated lower total length values compared to hypodivergent (P=0.006) and hyperdivergent patterns (P=0.033).
Conclusions: A statistically significant inverse relationship was observed between the distance from the cementoenamel junction to the vestibular bone crest and the total and intra-alveolar lengths in the studied regions. The total length was greatest in the region of the mesiobuccal root of the maxillary first molars, followed by the region of the distal root of the second molars, and finally the region of the distobuccal root of the maxillary first molars. Individuals with normodivergent patterns exhibited the lowest total infrazygomatic ridge height.
KEYWORDS: “Infrazygomatic bone crest” “Zygoma”; “Infrazygomatic”; “Cone-beam Computed Tomography”; “Craniofacial morphology”. “Temporary Skeletal Anchorage Devices”; “TSADs”