Starting with his mandible pushed forward so that his mandibular (lower) teeth were anterior to the maxillary (upper) teeth, the patient would forcefully pull his mandible back so that the lingual (back) surfaces of the mandibular incisors pushed against the buccal (outside) surfaces of the maxillary incisors.As part of Mr. G’s dental examination, we take a full series of intraoral radiographs. These reveal radiolucencies at the apices of teeth #23 through #26 (Photo 2). The films also show root canal therapy on tooth #26.
Differential diagnosis for lesions in the periapical region of the mandibular incisors includes periapical cemental dysplasia (PCD), which typically is found in middle-aged African-American females,5 and lesions resulting from non-vitality of the teeth. Histopathologically, lesions resulting from the latter include an apical abscess, cyst, or granuloma.
As is customary when periapical lesions are noted, we test the vitality of the affected teeth. None of the affected teeth responded to cold or electric pulp testing, which indicated they were non-vital. Tooth vitality is not affected in PCD, which allowed us to exclude this condition.
Non-vital teeth indicate that the pulpal tissue is necrotic. Most commonly, non-vitality occurs when decay has penetrated the pulp chamber or as a complication of physical trauma. No decay was present on Mr. G’s mandibular anterior teeth and he denied a history of trauma such as a blow to the teeth. This left his oral habit as the likely cause of non-vitality.
Treatment for a non-vital tooth is a root canal, which had been done on tooth #26. We successfully performed root canal on Mr. G’s other non-vital teeth. We informed the patient of reason for his non-vital teeth, and made a protective occlusal guard to try to prevent additional trauma to the affected teeth.
Recognizing oral habits
Restoration of worn teeth, particularly those of the mandibular anterior, is technically difficult and—depending on the nature of the restoration—quite expensive. Endodontic therapy is more successful in teeth without periapical disease.6 Thus, preventing tooth-related problems in patients who grind their teeth or engage in other destructive dental behaviors is important.
As this case illustrates, teeth can become non-vital without clinical evidence of tooth wear; clinical evidence may be subtle or nonexistent (note teeth #23, #24, and #25 in Photo 2). Absence of tooth wear is not a reliable sign of tooth vitality. Mild to moderate tooth wear usually goes unnoticed by patients and clinicians.7
Patients with bruxism may complain of masticatory muscle soreness or increased wear of the teeth.7 In extreme cases, they may self-extract teeth as a result of bruxism.8
Screen patients who have anxiety disorders or depression for signs of bruxism or related behaviors (Table 2). If you detect signs of bruxism or related behavior, refer the patient to a dentist. Ask the dentist to look for signs of wear and perform vitality testing of teeth on a regular basis (twice a year is reasonable). Any signs of changes in pulp vitality should be followed up with intraoral periapical radiographs, which these patients might need more frequently than FDA guidelines recommend.9
Table 2
Screening for bruxism: 3 questions for patients
| 1. Do you have pain or discomfort in the jaw or facial muscles, headaches or earaches, or increased tooth sensitivity? |
| 2. Have you noticed changes in the way your teeth fit together or wearing down of your teeth? |
| 3. Has your sleeping partner noticed any noise at night that might be the result of teeth grinding? |
An occlusal guard may provide the most definitive tooth protection for patients who engage in bruxism or similar behaviors. Occlusal guards are made of material that is softer than enamel, so the patient will wear away the guard rather than tooth structure. When the guard is worn away, the patient needs a new one.
Pharmacologic strategies for bruxism or related oral habits involving the teeth are not well developed. One short-term, placebo-controlled trial for acute treatment in 10 drug-free patients with sleep bruxism consisted of a predrug night, a placebo night, and a clonazepam night. Clonazepam, 1 mg 30 minutes before bedtime, significantly improved bruxism and sleep quality as determined by objective and subjective measures.10
Kast11 reported 4 cases in which tiagabine suppressed nocturnal bruxism, trismus, and consequent morning pain in the teeth, masticatory musculature, jaw, and temporomandibular joint areas. This gammaaminobutyric acid reuptake inhibitor anticonvulsant approved for treating partial seizures was dosed at 4 to 8 mg at bedtime. These dosages are lower than those used to treat seizures.