▋ Preoperative Condition

Mr. Yu, a 60-year-old warehouse logistics operator, had been wearing a mandibular removable denture for a long time. However, he experienced significant pain and was unable to eat properly.

The removable denture also accelerated alveolar ridge resorption in the posterior mandible, resulting in a pronounced Curve of Spee and an almost 100% deep bite.

▋ Treatment Plan

If full-mouth reconstruction without sacrificing the remaining dentition were to be considered, extensive bilateral vertical bone augmentation (V-GBR) in the posterior mandible would be required. This would be followed by implant-supported fixed prostheses to increase the occlusal vertical dimension (OVD), along with the modification or replacement of all existing restorations to accommodate the new occlusion.

The minimum treatment sequence would involve:

Two V-GBR surgeries
Two implant surgeries
Two soft tissue surgeries

A total of six surgical procedures, in addition to the subsequent prosthetic phases and associated costs, caused significant anxiety and discouragement for the patient.

Our core treatment philosophy emphasizes immediate function, with the goals of less pain, less suffering, and fewer complications. Therefore, we recommended a same-day full-mouth reconstruction with immediate implant-supported fixed prostheses.

▋ Caution in the Use of Surgical Guides

Many clinicians may assume that a surgical guide is necessary for accuracy in such cases. However, in this case of extremely narrow bone, two issues arise:

Poor stability of the surgical guide (especially in the mandible)
The bone consists primarily of cortical bone; after guided drilling, deviation may occur due to differences in density between the buccal and lingual cortical plates

In such cases, utilizing the patient’s anatomical landmarks, sensing differences in bone density, and manually adjusting the drilling direction provide a more accurate approach for implant placement.

▋ Surgical Tip

Flatten the alveolar ridge before implant placement.

This allows for a more hygienic tissue–prosthesis interface. If implant platforms are placed at uneven levels, the interface will be irregular, increasing difficulty in oral hygiene and raising the risk of future complications.

▋ Considerations for Full-Mouth Reconstruction in Deep Bite

Implant-supported full-arch prostheses are generally not recommended with a deep bite occlusal design, as excessive lateral forces during anterior guidance can be detrimental to implants.

Therefore, increasing the OVD is essential to correct the deep bite.

▋ Tongue Space Consideration

In patients with long-term posterior mandibular edentulism, tongue space must be carefully evaluated.

If the patient has a relatively large tongue, posterior teeth should not be positioned too lingually (and in some cases may require a crossbite arrangement). Patients should be informed preoperatively that tongue space will change after prosthesis delivery and may require an adaptation period.

▋ Postoperative Follow-up

At the 3-year follow-up, the prosthesis was removed for maintenance. Soft tissue conditions were stable, with only minimal calculus accumulation around the abutments.

(Postoperative CBCT at 2 years is available in the comments section.)

▋ Conclusion

Although this case may appear straightforward, successful management of deep bite correction and prosthetic occlusal design requires close collaboration between the surgical and prosthetic teams.

One of the greatest challenges in the mandible is the presence of thin and dense cortical bone, which increases the risk of failure if not carefully managed. This case demonstrates that even without surgical guides or navigation systems, precise implant placement and immediate function can still be achieved.

Accurate identification of anatomical structures, continuous adjustment of drilling angulation based on tactile feedback, and maintaining appropriate insertion torque (avoiding excessive torque) are critical for success in complex cases.

Clinicians must remain vigilant regarding the three major risks in mandibular implant surgery:

Overheating
Excessive insertion torque
Mandibular fracture