Analysis of crown size and morphology, and gingival shape in the maxillary anterior dentition in Korean young adults

PURPOSE: The aim of this investigation was to analyze the dimensions of clinical crowns and to classify the crown and the gingival type in the anterior teeth in Korean young adults. MATERIALS AND METHODS: Casts were obtained from 50 subjects ranging in age from 24 to 32. Measurements of length and width were made on the casts using a pair of digital calipers on the entire dentition. Crown thickness and papilla height were also measured and MDW/CL (mesiodistal width to clinical length) and CW/CL (cervical width to clinical length) ratios of the maxillary anterior teeth were calculated. The K-clustering method was used for CW/CL to classify the anterior tooth shape into three groups (tapered, ovoid, and square), and one-way analysis of variance and Duncan's post-hoc comparison were used to evaluate statistical significance between the groups. Pearson's correlation analysis was performed between tooth shape and papillary height (PH) to demonstrate the correlation between tooth shape and gingival morphological characteristics. RESULTS: The average length of the maxillary central incisors was 9.89 mm; the mesio-distal width was 8.54 mm; and the ratio of width/length was 0.86 in Korean young adults. The average bucco-palatal thickness of the central incisor was 3.14 mm at the incisal 1/3 aspect. Ovoid type was the most common tooth shape (48%), followed by square type (29%) and taper type (23%) in the central incisors of Korean young adults. Tooth shape and gingival type were correlated with each other. CONCLUSION: New reference data were established for tooth size in Korean young adults and the data show several patterns of tooth shape and gingival type. Clinicians should diagnose and treat based on these characteristics for better results in the Korean population.

Analysis of dimensions and shapes of maxillary and mandibular dental arch in Korean young adults

PURPOSE: The aim of this study was to investigate dental arch dimensions and to classify arch shape in Korean young adults. MATERIALS AND METHODS: The sample included 50 Koreans with age ranging from 24 to 32 years. Maxillary and mandibular casts were fabricated using irreversible hydrocolloid and type III dental stones. Incisor-canine distance, incisor-1(st) molar distance, incisor-2(nd) molar distance, intercanine distance, inter-1(st) molar distance, and inter-2(nd) molar distance in both the maxillary and mandibular arch were measured using a three-dimensional measuring device. The dental arch was classified into three groups using five ratios from the measured values by the K-means clustering method. The data were analyzed with one-way analysis of variance. RESULTS: Arch lengths (IM2D, incisal-2(nd) molar distance) were 44.13 mm in the maxilla and 40.40 mm in the mandible. Arch widths (M2W, inter 2(nd) molar width) were 64.12 mm in the maxilla and 56.37 mm in the mandible. Distribution of the dental arch form was mostly ovoid shape (maxilla 52% and mandible 56%), followed by the V-shape and the U-shape. The arch width for the U-shape was broader than for the other forms. CONCLUSION: This study establishes new reference data for dental arch dimensions for young Korean adults. The most common arch form is the ovoid type in the maxilla and mandible of Koreans. Clinicians should be aware of these references and classify arch type before and during their dental treatment for effective and harmonized results in Koreans.

Rebleeding of Ruptured Intracranial Aneurysms in the Immediate Postoperative Period after Coil Embolization

OBJECTIVE: Early rebleeding after coil embolization of ruptured intracranial aneurysms is rare, however serious and fatal results of rebleeding have been reported. We studied the incidence and angiographic and clinical characteristics of rebleeding of ruptured aneurysms occurring in the immediate postoperative period after coil embolization. MATERIALS AND METHODS: We analyzed patients who had aneurysmal subarachnoid hemorrhage and underwent coil embolization. Patients with dissecting aneurysms, blood blister-like aneurysms, fusiform aneurysms, and pseudoaneurysms were excluded. This study included 330 consecutive patients. The clinical and radiological data of 7 of these patients with acute rebleeding after coil embolization were reviewed. RESULTS: The incidence of rebleeding of ruptured aneurysms after coil embolization was 2.1% (7/330), and all cases of rebleeding occurred in the immediate postoperative period within 3 days after coiling. The radiological characteristics were as follows: anterior communicating artery (ACoA) aneurysm (71.4%, 5/7); presence of intracerebral hemorrhage (ICH, 71.4%, 5/7); dome-to-neck ratio < 2 (42.9%, 3/7); presence of bleb (42.9%, 3/7); and subtotal occlusion of aneurysm after coiling (14.3%, 1/7). A thrombolytic agent was administered in 1 patient and continued anticoagulation was performed in 2 patients. Rebleeding patients showed a very poor outcome (Glasgow Outcome Scale 1, 85.7%, 6/7). CONCLUSION: The prognosis of early rebleeding was very poor. Location of aneurysms on ACoA, the unilateral hypoplasia of A1 segment, presence of ICH and bleb, and adverse events during the procedure were probably associated with early rebleeding of ruptured intracranial aneurysms in the immediate postoperative period after coil embolization.

Spontaneous Occluded Anterior Communicating Artery Aneurysm during Coil Embolization Treated with One Coil Insertion into Remaining Stump

Spontaneous thrombosis of a ruptured aneurysm during coil embolization is a rare event, and some reports on recanalization of a spontaneous occluded ruptured aneurysm have been published. We report on a case of a 54-year-old male who presented with a subarachnoid hemorrhage due to rupture of a small aneurysm of the anterior communicating artery (ACoA). Cerebral angiography confirmed the presence of the ACoA aneurysm, but, during coil embolization, the aneurysm was near completely occluded with a remaining small neck. A small coil was inserted into the remaining stump of the neck to prevent recanalization, and the angiographic result at 1 year after coil embolization showed complete obliteration of the aneurysm.