Levator nasolabialis muscle transposition to prevent an orosinus fistula after tooth extraction in horses.

This study looks at a new technique where the levator nasolabialis muscle was moved (transposed) to prevent the formation of an orosinus fistula after tooth extraction in horses. This method was effective, with no formation of these fistulas after the procedure. Histological investigations showed that the moved muscles gradually transitioned into fibrous tissue and maintained viability with no facial deformities or loss of nasal function.

Method and Purpose of the Research

• The study involved transposing the ventral part of the levator nasolabialis muscle to the alveolar defect in horses who have undergone a sinusotomy and tooth extraction. This was done with the intention of preventing an orosinus fistula, an abnormal connection or passage between the oral cavity and the sinus resulting from tooth extraction.
• The study was conducted on five normal horses and six horses that had a tooth root abscess and sinusitis.

Key Outcomes

• In the normal horses, the transposed muscle remained viable at weeks 6, 10, 14, and 18 post-operation, and no orosinus fistulae were formed. This suggests that the technique was successful in preventing fistula formation.
• Additionally, the tissue samples taken from the horses revealed a progressive transition from muscle to fibrous tissue, implying successful integration of transposed muscles into recipient sites.
• Importantly, the procedure did not result in facial deformity or loss of nasal function at the donor site, indicating that it was well-tolerated.

Case of Abscess

• One of the cases resulted in a localized abscess, which was associated with incomplete removal of tooth root fragments. This case demonstrates the importance of thorough tooth root extraction to prevent complications.

Long-Term Results

• The long-term results of the procedure were also examined. After a year or more, five of the six horses treated for dental disease displayed a complete resolution of clinical symptoms, indicating long-term success of the technique.
• However, one horse continued to show intermittent mild nasal discharge, which raises the need for further investigation to refine the technique and minimize potential side effects.