Recommended by Dr. med. dent. Thomas Meier and PD Dr. med. Dr. med. dent. David Schneider
Insights from this study for clinical practice
Understanding the natural remodeling process of the alveolar ridge following tooth extraction is essential for clinical decision-making. The pronounced resorption of the buccal bone wall, particularly in the early healing phase, underscores the importance of considering these dimensional changes when planning for future implant placement and prosthetic rehabilitation.
The volume and shape of the alveolar ridge is determined by the form of the associated teeth. So what happens if a tooth is removed? That is the subject of this paper, a partnership between researchers from Brazil and Sweden.
«The objective of the present experiment in the dog was to study some dimensional alterations of the alveolar ridge that occurred following tooth extraction as well as processes of bone modelling and remodelling associated with such change.»
Araujo and Lindhe in the cited publication
Twelve dogs each had four premolars hemi-sected, with the distal roots removed. The extractions were timed such that, at sacrifice, each dog had sites representing 1, 2, 4, and 8 weeks of healing. Sections were created and stained to allow visualization of the bone healing process. At all timepoints, measurements were taken to allow comparison of the buccal and lingual bone walls.
PD Dr. med. Dr. med. dent. David Schneider
In this publication, the dimensional and histologic changes after extraction are presented as a basis for clinical decisions regarding implantation timing, ridge prophylaxis and augmentation procedures.
The paper describes the different histological features at each time point. At 1 week there were modest signs of inflammation, and the extraction socket was filled with coagulum, granulation tissue, provisional matrix, and some newly formed bone. By 2 weeks there were no inflammatory cells in the mucosa and there was a large amount of newly formed bone in the apical and lateral areas of the extraction socket. At 4 weeks a large proportion of lamellar bone had been replaced by woven bone, with a large number of osteoclasts on its outer surface indicating remodeling. By the last observation at 8 weeks, the entrance of the extraction socket was sealed with a combination of woven and lamellar bone.
As well as creation of new bone, the healing process involves removal of unnecessary tissue. Bundle bone anchors teeth to the jaw, and thus loses its function after tooth extraction. As such, the paper describes the decreasing amounts of bundle bone around the extraction socket over time. At 1 week, the inner surfaces of the socket walls were lined with bundle bone, with occasional osteoclasts. The crestal regions of the bone walls were solely bundle bone, which was taller at the buccal than the lingual wall. By 4 weeks post-extraction, there was no bundle bone in the crestal region of the bone walls.
«Marked dimensional alterations occurred during the early phase – 8 weeks – following the extraction of mandibular premolars.»
Araujo and Lindhe in the cited publication
As well as histological observations, the researchers describe the bone resorption leading to reduced height of the bone walls. This reduction was more pronounced at the buccal than lingual bone wall, possibly due to the crest of the buccal bone wall being solely bundle bone.
Dr. med. dent. Thomas Meier
This paper describes the remodeling processes and changes occurring to the bone after tooth extraction – important knowledge for dental practitioners.
The authors conclude that resorption at the extraction site occurred in two phases: first, bundle bone was resorbed and replaced by woven bone (leading to height reduction of the buccal crest); and second, resorption from the outer surfaces of both bone walls, for reasons unknown. These findings, and the histological details, are of interest for any dental practitioner planning tooth extraction and implantation procedures.
