Evaluation of the Vertical Bone Height of the Palate using CBCT for Placing Micro Implants- A Pilot Study

Abstract

Introduction: Determining an ideal anatomical location for mini-implant placement is very crucial for successful use of mini-implants in an orthodontic setup. Some of the factors that should be considered while selecting an ideal site for implant placement are soft tissue morphology, interradicular distance, sinus morphology, nerve location, buccolingual bone depth, and cortical thickness. In maxilla, implants are commonly placed in the buccal bone in the anterior and posterior inter radicular regions but in certain instances there is a need to place implants on the palatal side. Median and paramedian sites are recommended for placement of mini-implants in the hard palate. It is important that the measurement of the available vertical bone height is carried out to select the ideal location for placing a mini-implant since this will directly influence stability, and thus success. Aim: This study aims to evaluate the Vertical Bone Height (VBH) of the palate using a CBCT (Cone Beam Computed Tomography) at different coronal sections postero-anteriorly so as to determine the ideal location for implant placement. Materials and Methods: This is a cross-sectional study carried out in the department of Orthodontics, Kyungpook national university dental hospital, Daegu from February 2018 to march 2018. CBCT records of 12 patients referred to the department of orthodontics were selected. Sample consisted of 6 adults above 18 years (3 females and 3 males), and 6 children below the age of 18 years (3 females and 3 males). The images were analysed using InVivoDental (Anatomage Inc., San Jose, CA, USA), a volumetric imaging software. The CBCT analysis involves evaluation of series of coronal sections starting from the most posterior section of the palate extending up to the anterior section. In each section, the VBH of the palate was measured at a distance of 5 mm and 10 mm lateral to the midpalate suture on the right and left side. Results: In adults: the greatest bone height is seen in area mesial to the 1st premolar with a mean of 14.77 mm at a distance of 5 mm from the midline and mean of 17.53 mm at a distance of 10 mm from the midline. In children: the greatest bone height is seen in area mesial to the 1st deciduous molar with a mean of 14.04 mm at a distance of 5 mm from the midline and mean of 16.7 mm at a distance of 10 mm from the midline. The mean Palatal height is higher at 10 mm lateral to midline when compared to 5 mm lateral to midline at every coronal section. The mean palatal height is more in males than in females. No significant difference is seen between the palatal height on the right and the left side. Conclusion: The palate presents a site of choice for the insertion of miniscrews for orthodontic purposes as it acts as a safe haven for both novice and experienced orthodontists. The thickest part of the palate is the antero-lateral part of the palate. Further multicentric studies with larger sample size in different age ranges are required for better understanding of efficiency and success of palatal implants.

Keywords

• cone beam computed tomography
• diagnostic images
• micro implant
• palatal height
• vertical bone height