Surgical Management of Unilateral Maxillary Molar Teeth Impaction in a Horse.

Overview

• This study reports on a rare case of congenital impaction of three successive maxillary molar teeth in a horse and details the surgical approach, postoperative management, and long-term outcomes of the treatment.

Background and Case Description

• Impaction of permanent cheek teeth—where teeth fail to erupt properly—is a more common problem in the lower jaw (mandible) of horses.
• Maxillary (upper jaw) molar teeth impactions are rare, making this case particularly unusual.
• The subject was a 4-year-old mare with congenital impaction of three successive maxillary molars, indicating the condition was present from birth.

Diagnostic Imaging

• Computed Tomography (CT) scanning was utilized to assess the spatial relationships of the impacted teeth.
• CT revealed complex anatomical relationships between the impacted teeth, the sinus floor, and nearby structures.
• These relationships were inadequately visualized using conventional radiography, demonstrating the advantage and importance of CT for surgical planning in such cases.

Surgical Management

• A maxillary sinus bone flap surgical approach was employed, allowing access to the impacted teeth through the sinus.
• This method enabled controlled sectioning (cutting) and removal of the three affected molars.
• Bone samples from the sinus floor were collected during surgery for histopathologic analysis.

Histopathological Findings

• Analysis of sinus floor bone revealed reactive osteosclerosis, a thickening and hardening of the bone.
• This bone response was consistent with chronic pressure exerted by the impacted teeth and/or ongoing sinus inflammation.

Postoperative Complications and Management

• Following surgery, the mare developed an oromaxillary communication, an abnormal opening between the oral cavity and the maxillary sinus.
• Secondary sinusitis (infection/inflammation of the sinus) also occurred, partly due to the loss of polysiloxane putty, which was likely used as a packing or sealant material during surgery.
• These complications were managed through staged debridement (removal of damaged tissue) and sinoscopic lavage, a minimally invasive technique to clean and irrigate the sinus.

Long-Term Outcome

• Despite the loss of multiple maxillary cheek teeth, the long-term follow-up indicated satisfactory oral function and comfort for the horse.
• This suggests that even extensive surgical intervention for rare, complex impactions can result in acceptable functional outcomes in equine patients.

Summary

• The case highlights the rarity of maxillary molar impactions in horses and emphasizes the use of advanced imaging (CT) for accurate diagnosis and surgical planning.
• The surgical technique via a maxillary sinus bone flap was effective in removing impacted teeth while minimizing complications.
• Postoperative management of complications is critical to recovery, and the mare achieved good functional status in the long term.