Complications with Extractions

1. Introduction

Complications involving cheek teeth extractions are prevalent. More than half of all cheek teeth extraction cases have a potential for complication.^1,2 Complications may involve surrounding bone, sinus, soft tissue (peridontium, vascular, nerves, etc), and teeth. The extraction process should never be viewed as a simple one-stop procedure. In contrast, an extraction should be a process that involves (1) presurgical/extraction evaluation, (2) treatment planning, (3) contingency treatment planning, (4) the extraction, and (5) postsurgical/extraction evaluation. To avoid or minimize complications, a systematic approach involving intraoral and radiographic examinations should always be instituted. Additional modalities for evaluation such as computed tomography, endoscopy, histopathology, cytology, and microbiology may be indicated before attempting an extraction procedure. Potential complications would include (but are not limited to) palatine artery laceration, iatrogenic mandible fracture, dilacerated roots, reactive cementum from chronic apical disease, alveolar bone sequestration, alveolar plug failure, oroantral fistula, iatrogenic dental fracture, retained or fractured roots, iatrogenic maxillary fracture, lingual laceration after a long-acting nerve block, collateral damage during the extraction process, and nonhealing mandibular fracture due to alveolar involvement and severe periodontal disease.

2. Materials and Methods

Oral and radiographic examination equipment/ techniques required for the evaluation of extractions has been thoroughly reviewed previously.^3–12 Sedation protocols using constant rate infusion¹³ along with regional nerve blocks^14,15 allow for most extraction procedures to be performed as a standing procedure.¹⁶

Palatine Artery Laceration

The greater palatine artery courses subgingival along the medial aspect of the maxillary cheek teeth at the edge of the hard palate within the palatine groove/process. It is a direct extension of the maxillary artery that passes through the palatine canal and extends rostral and joins its counterpart (right and left palatine artery) caudal to the incisors and enters the interincisive canal to form the incisive artery. The palatine groove does not completely enclose/protect the palatine artery. The artery is in close opposition to the alveolar bone of the maxillary cheek teeth. If extensive pathology is present along the medial/palatal alveolar wall, there is a risk of lacerating or tearing the artery when attempting an extraction. If a palatine artery laceration occurs, treatment involves direct pressure with surgical towels over a sustained period of time (20 to 30 minutes). Due to the location of the palatine artery within the palatine groove, surgical ligation is typically not possible.

Iatrogenic Mandible Fracture

The anatomical structure of a mandible consists of light alveolar and cancelous bone enveloped with a cortical plate on the medial and lateral aspect; most of the strength of the mandible is actually attributed to the large cheek teeth embedded within the bone. When planning treatment for the extraction of a mandibular cheek tooth, complete oral and radiographic evaluations are indicated for both mandibles. Strength for mastication during the postextraction healing period will be supported by the contralateral mandible. Evaluations for the (1) quality of bone, (2) pathology involving additional mandibular cheek teeth, and (3) missing mandibular cheek teeth are necessary to determine the strength of the mandibles during post extraction healing and mastication. Horses should be evaluated for chronic systemic diseases (such as Cushing’s disease), periodontal disease, and so forth, which might affect the strength and quality of bone.

An evaluation of the extraction technique should be considered. If excessive force is needed with an intraoral or repulsion technique, severe damage and/or fracture of the surrounding bone is a possible complication. In contrast, a buccotomy and osteotomy technique may have less trauma involved with the extraction,^17,18 but if the bone is of poor quality/ density, the excess removal of buccal bone may cause weakness in the overall strength of the mandible and a fracture could occur with the remaining lingual portion of the cortical bone.

Dilacerated Roots

A dilacerated root may occur with malformation, maleruption, trauma, crowding, or chronic apical disease. If a tooth is evaluated with a dilacerated root, a comprehensive treatment plan must be instituted with several options available, depending on the outcome. If standard intraoral techniques fail in the extraction process, alternative plans would include a root tip sectioning and/or a buccotomy with surgical extraction.^17,18 Excessive rotational oral extraction forces could lead to additional complications, including iatrogenic tooth fracture and devitalized alveolar bone (sequestra).

Reactive Cementum Due to Chronic Apical Disease

Unlike other species, the equine tooth reacts to insults and infection by trying to seal or wall off bacteria with a layer of cementum.¹⁹ With chronic apical disease in cheek teeth there may be surges/ flares of infection, followed with quiescent periods with cementum overgrowth. The abundant layers of cementum can create a moderate ankylosis that will inhibit or prohibit normal cheek tooth eruption. A tooth with excessive cemental buildup and/or ankylosis may need additional extraction techniques implemented if oral extraction fails. Careful oral and radiographic evaluations will help when developing an accurate treatment plan. Aggressive oral extraction forces could lead to other complications, such as iatrogenic fracture of tooth or bone, retained root tips, alveolar bone damage, sequestra formation, and so forth.  [...]