Anatomical study of the pyramidal process of the palatine bone in relation to implant placement in the posterior maxilla

Abstract

The placement of dental implants in the molar region of the maxilla is often difficult because of insufficient bone volume and the inferior bone quality. In order to avoid these limitations, the pillar of bone, which is composed of the maxillary tuberosity, the pyramidal process of the palatine bone and the pterygoid process of the sphenoid bone, was introduced for implant placement. In fact, the pyramidal process is the posterior structure where implants are placed but until now, there is no available data of the size or shape of the pyramidal process. Therefore, we measured the height, anteroposterior distance and mediolateral distance of the pyramidal process and observed the shape of lateral and posterior surfaces of the pyramidal process of 54 Korean edentulous dry skulls in this study. The height was 13.1 mm (male: 13.6 mm, female: 12.4 mm). The anteroposterior distance was 6.5 mm (male: 6.7 mm, female: 6.1 mm). The mediolateral distance was 9.5 mm (male: 9.9 mm, female: 9.0 mm). The most common type was the right-angled triangle in the lateral surface (44.4%) and in the posterior surface (66.7%). There was no statistical significance between the male and the female in all items (P > 0.05). These results provide anatomical features in relation to placement of dental implants in the molar region of the maxilla and would be useful in treatment planning of partially or completely edentulous patients.

Implants in the pterygoid region: a systematic review of the literature

“…It subsequently proceeds upwards between both wings of the pterygoid processes and finds its encroachment in the pterygoid or scaphoid fossa of the sphenoid bone 21,43 . The pyramidal and pterygoid processes are composed of dense cortical bone and the average thickness of bone at their juncture is 6-6.7 mm 21,25 . If an implant is passed through this juncture at an angle of 45 degrees, it can incorporate up to 8-9 mm of dense cortical bone and its apex protrudes 2 mm into the pterygoid fossa 21 .…”

Placement of dental implants in the maxillary tuberosity: a systematic review

“…Twenty full-texts were excluded for the following reasons: clinical case studies, 22,[28][29][30]36,40,41 biomechanical study, 42 orthodontic study, 43,44 data not localized, 45 morphometric study, 46 in vitro study, 47 anatomical and radiological study, 35,48 and implants not placed in the region of the tuberosity or missing data. [49][50][51][52][53] Since there are few studies addressing the topic, relevant excluded clinical studies are summarized in Table 2.…”

“…20,21,[23][24][25][26][32][33][34][35] A systematic review indicated a 92% survival rate (first year) for implants placed in the pterygoid region 20 ; however, evidence-based reviews addressing implants placed in the tuberosity region are scarce.…”

“…32 The pyramidal process of the palatine bone and the pterygoid process of the sphenoid are dense cortical bone. 20,32,35 …”

Management of the posterior maxilla in the compromised patient: historical, current, and future perspectives

“…If the height, length, and/or width of the tuberosity are not adequate, however, the implant can be angled and the apex made to engage either the pterygoid process, the pyramidal plate of the palatine bone, or both. Recent observations and measurement of the height, anteroposterior distance, and mediolateral distance of the pyramidal process indicate that placement of implants in the lower half of the pyramidal process is advantageous (36).…”