Anatomical consideration for optimal position of orthodontic miniscrews in the maxilla: a CBCT appraisal

• Published in: Annals of Saudi medicine Vol. 40; no. 4; pp. 330 - 337
• Main Authors: Al Amri, Maha S, Sabban, Hanadi M, Alsaggaf, Doaa H, Alsulaimani, Fahad F, Al-Turki, Ghassan A, Al-Zahrani, Mohammad S, Zawawi, Khalid H
• Format: Journal Article
• Language: English
• Published: Saudi Arabia King Faisal Specialist Hospital and Research Centre 01.07.2020
• Subjects: Adult; Bone Screws; Cone-Beam Computed Tomography; Cross-Sectional Studies; Female; Humans; Male; Maxilla - anatomy & histology; Maxilla - diagnostic imaging; Maxillary Sinus - anatomy & histology; Maxillary Sinus - diagnostic imaging; Nasal Cavity - anatomy & histology; Nasal Cavity - diagnostic imaging; Original; Orthodontic Anchorage Procedures - instrumentation; Orthodontic Anchorage Procedures - methods; Retrospective Studies; Young Adult
• ISSN: 0256-4947; 0975-4466
• DOI: 10.5144/0256-4947.2020.330

Orthodontic miniscrews are commonly used as temporary anchorage devices. Bone thickness and bone depth are important factors when placing miniscrews. There are no studies to assess the maxillary bone thickness for optimum miniscrew placement in a Saudi population. Assess the proximity of the maxillary sinus and nasal cavity in areas where miniscrews are usually inserted using cone beam computed tomography (CBCT). Retrospective, cross-sectional. Department of maxillofacial radiology in a Saudi dental school. Using CBCT images, we measured the distance between the maxillary sinus and nasal cavity to the palatal bone, buccal intra-radicular and infrazygomatic crest areas. Mean values (SD) were compared at various locations, including by gender, and correlation with age was calculated. Mean bone thickness at commonly used sites for orthodontic miniscrew placements in the maxilla. Secondary outcome was the insertion angle in the infrazygomatic crest area. CBCT images of 100 patients (50 males and 50 females). The mean (standard deviation) age for the sample was 25.4 (6.5) years with no significant difference between males and females. In the palate, the distance to the nasal cavity and maxillary sinus was greater anteriorly and decreased significantly posteriorly ( <.001). Buccally, the interdental bone depth was significantly greater between the second premolar and first molar (11.96 mm) compared to between the central and lateral incisors (7.53 mm, <.001). The mean bone thickness of the infrazygomatic crest area at a 45° insertion angle was 4.94 mm compared to 3.90 at a 70° insertion angle ( <.001). No correlation was found between age and bone thickness. The distance to the nasal cavity and maxillary sinus was greater in the anterior than posterior areas. There is minimal risk of injuring the maxillary sinus or nasal cavity using the buccal approach. Caution is needed when placing miniscrews in the infrazygomatic crest area. Cross-sectional study from one center; hence, findings cannot be generalized to other populations. None.